v4.19.13 snapshot.
diff --git a/ipc/Makefile b/ipc/Makefile
new file mode 100644
index 0000000..c2558c4
--- /dev/null
+++ b/ipc/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux ipc.
+#
+
+obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o syscall.o
+obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
+obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o
+obj-$(CONFIG_IPC_NS) += namespace.o
+obj-$(CONFIG_POSIX_MQUEUE_SYSCTL) += mq_sysctl.o
+
diff --git a/ipc/compat.c b/ipc/compat.c
new file mode 100644
index 0000000..5ab8225
--- /dev/null
+++ b/ipc/compat.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 32 bit compatibility code for System V IPC
+ *
+ * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
+ * Copyright (C) 2000 VA Linux Co
+ * Copyright (C) 2000 Don Dugger <n0ano@valinux.com>
+ * Copyright (C) 2000 Hewlett-Packard Co.
+ * Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 2000 Gerhard Tonn (ton@de.ibm.com)
+ * Copyright (C) 2000-2002 Andi Kleen, SuSE Labs (x86-64 port)
+ * Copyright (C) 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2001 IBM
+ * Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Copyright (C) 2004 Arnd Bergmann (arnd@arndb.de)
+ *
+ * This code is collected from the versions for sparc64, mips64, s390x, ia64,
+ * ppc64 and x86_64, all of which are based on the original sparc64 version
+ * by Jakub Jelinek.
+ *
+ */
+#include <linux/compat.h>
+#include <linux/errno.h>
+#include <linux/highuid.h>
+#include <linux/init.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
+#include <linux/syscalls.h>
+#include <linux/ptrace.h>
+
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+
+#include "util.h"
+
+int get_compat_ipc64_perm(struct ipc64_perm *to,
+ struct compat_ipc64_perm __user *from)
+{
+ struct compat_ipc64_perm v;
+ if (copy_from_user(&v, from, sizeof(v)))
+ return -EFAULT;
+ to->uid = v.uid;
+ to->gid = v.gid;
+ to->mode = v.mode;
+ return 0;
+}
+
+int get_compat_ipc_perm(struct ipc64_perm *to,
+ struct compat_ipc_perm __user *from)
+{
+ struct compat_ipc_perm v;
+ if (copy_from_user(&v, from, sizeof(v)))
+ return -EFAULT;
+ to->uid = v.uid;
+ to->gid = v.gid;
+ to->mode = v.mode;
+ return 0;
+}
+
+void to_compat_ipc64_perm(struct compat_ipc64_perm *to, struct ipc64_perm *from)
+{
+ to->key = from->key;
+ to->uid = from->uid;
+ to->gid = from->gid;
+ to->cuid = from->cuid;
+ to->cgid = from->cgid;
+ to->mode = from->mode;
+ to->seq = from->seq;
+}
+
+void to_compat_ipc_perm(struct compat_ipc_perm *to, struct ipc64_perm *from)
+{
+ to->key = from->key;
+ SET_UID(to->uid, from->uid);
+ SET_GID(to->gid, from->gid);
+ SET_UID(to->cuid, from->cuid);
+ SET_GID(to->cgid, from->cgid);
+ to->mode = from->mode;
+ to->seq = from->seq;
+}
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
new file mode 100644
index 0000000..8ad93c2
--- /dev/null
+++ b/ipc/ipc_sysctl.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (C) 2007
+ *
+ * Author: Eric Biederman <ebiederm@xmision.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include <linux/module.h>
+#include <linux/ipc.h>
+#include <linux/nsproxy.h>
+#include <linux/sysctl.h>
+#include <linux/uaccess.h>
+#include <linux/ipc_namespace.h>
+#include <linux/msg.h>
+#include "util.h"
+
+static void *get_ipc(struct ctl_table *table)
+{
+ char *which = table->data;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
+ return which;
+}
+
+#ifdef CONFIG_PROC_SYSCTL
+static int proc_ipc_dointvec(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = get_ipc(table);
+
+ return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
+}
+
+static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = get_ipc(table);
+
+ return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
+}
+
+static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ipc_namespace *ns = current->nsproxy->ipc_ns;
+ int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+ if (err < 0)
+ return err;
+ if (ns->shm_rmid_forced)
+ shm_destroy_orphaned(ns);
+ return err;
+}
+
+static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = get_ipc(table);
+
+ return proc_doulongvec_minmax(&ipc_table, write, buffer,
+ lenp, ppos);
+}
+
+static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+ int dummy = 0;
+
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = &dummy;
+
+ if (write)
+ pr_info_once("writing to auto_msgmni has no effect");
+
+ return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
+}
+
+#else
+#define proc_ipc_doulongvec_minmax NULL
+#define proc_ipc_dointvec NULL
+#define proc_ipc_dointvec_minmax NULL
+#define proc_ipc_dointvec_minmax_orphans NULL
+#define proc_ipc_auto_msgmni NULL
+#endif
+
+static int zero;
+static int one = 1;
+static int int_max = INT_MAX;
+
+static struct ctl_table ipc_kern_table[] = {
+ {
+ .procname = "shmmax",
+ .data = &init_ipc_ns.shm_ctlmax,
+ .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
+ .mode = 0644,
+ .proc_handler = proc_ipc_doulongvec_minmax,
+ },
+ {
+ .procname = "shmall",
+ .data = &init_ipc_ns.shm_ctlall,
+ .maxlen = sizeof(init_ipc_ns.shm_ctlall),
+ .mode = 0644,
+ .proc_handler = proc_ipc_doulongvec_minmax,
+ },
+ {
+ .procname = "shmmni",
+ .data = &init_ipc_ns.shm_ctlmni,
+ .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec,
+ },
+ {
+ .procname = "shm_rmid_forced",
+ .data = &init_ipc_ns.shm_rmid_forced,
+ .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax_orphans,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+ {
+ .procname = "msgmax",
+ .data = &init_ipc_ns.msg_ctlmax,
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "msgmni",
+ .data = &init_ipc_ns.msg_ctlmni,
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "auto_msgmni",
+ .data = NULL,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_ipc_auto_msgmni,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+ {
+ .procname = "msgmnb",
+ .data = &init_ipc_ns.msg_ctlmnb,
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "sem",
+ .data = &init_ipc_ns.sem_ctls,
+ .maxlen = 4*sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec,
+ },
+#ifdef CONFIG_CHECKPOINT_RESTORE
+ {
+ .procname = "sem_next_id",
+ .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
+ .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "msg_next_id",
+ .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
+ .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "shm_next_id",
+ .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
+ .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+#endif
+ {}
+};
+
+static struct ctl_table ipc_root_table[] = {
+ {
+ .procname = "kernel",
+ .mode = 0555,
+ .child = ipc_kern_table,
+ },
+ {}
+};
+
+static int __init ipc_sysctl_init(void)
+{
+ register_sysctl_table(ipc_root_table);
+ return 0;
+}
+
+device_initcall(ipc_sysctl_init);
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
new file mode 100644
index 0000000..68d4e95
--- /dev/null
+++ b/ipc/mq_sysctl.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2007 IBM Corporation
+ *
+ * Author: Cedric Le Goater <clg@fr.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include <linux/nsproxy.h>
+#include <linux/ipc_namespace.h>
+#include <linux/sysctl.h>
+
+#ifdef CONFIG_PROC_SYSCTL
+static void *get_mq(struct ctl_table *table)
+{
+ char *which = table->data;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
+ return which;
+}
+
+static int proc_mq_dointvec(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table mq_table;
+ memcpy(&mq_table, table, sizeof(mq_table));
+ mq_table.data = get_mq(table);
+
+ return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
+}
+
+static int proc_mq_dointvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table mq_table;
+ memcpy(&mq_table, table, sizeof(mq_table));
+ mq_table.data = get_mq(table);
+
+ return proc_dointvec_minmax(&mq_table, write, buffer,
+ lenp, ppos);
+}
+#else
+#define proc_mq_dointvec NULL
+#define proc_mq_dointvec_minmax NULL
+#endif
+
+static int msg_max_limit_min = MIN_MSGMAX;
+static int msg_max_limit_max = HARD_MSGMAX;
+
+static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
+static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
+
+static struct ctl_table mq_sysctls[] = {
+ {
+ .procname = "queues_max",
+ .data = &init_ipc_ns.mq_queues_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec,
+ },
+ {
+ .procname = "msg_max",
+ .data = &init_ipc_ns.mq_msg_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_max",
+ .data = &init_ipc_ns.mq_msgsize_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
+ {
+ .procname = "msg_default",
+ .data = &init_ipc_ns.mq_msg_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_default",
+ .data = &init_ipc_ns.mq_msgsize_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
+ {}
+};
+
+static struct ctl_table mq_sysctl_dir[] = {
+ {
+ .procname = "mqueue",
+ .mode = 0555,
+ .child = mq_sysctls,
+ },
+ {}
+};
+
+static struct ctl_table mq_sysctl_root[] = {
+ {
+ .procname = "fs",
+ .mode = 0555,
+ .child = mq_sysctl_dir,
+ },
+ {}
+};
+
+struct ctl_table_header *mq_register_sysctl_table(void)
+{
+ return register_sysctl_table(mq_sysctl_root);
+}
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
new file mode 100644
index 0000000..c0d58f3
--- /dev/null
+++ b/ipc/mqueue.c
@@ -0,0 +1,1594 @@
+/*
+ * POSIX message queues filesystem for Linux.
+ *
+ * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl)
+ * Michal Wronski (michal.wronski@gmail.com)
+ *
+ * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
+ * Lockless receive & send, fd based notify:
+ * Manfred Spraul (manfred@colorfullife.com)
+ *
+ * Audit: George Wilson (ltcgcw@us.ibm.com)
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/capability.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/sysctl.h>
+#include <linux/poll.h>
+#include <linux/mqueue.h>
+#include <linux/msg.h>
+#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <linux/netlink.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <linux/signal.h>
+#include <linux/mutex.h>
+#include <linux/nsproxy.h>
+#include <linux/pid.h>
+#include <linux/ipc_namespace.h>
+#include <linux/user_namespace.h>
+#include <linux/slab.h>
+#include <linux/sched/wake_q.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/user.h>
+
+#include <net/sock.h>
+#include "util.h"
+
+#define MQUEUE_MAGIC 0x19800202
+#define DIRENT_SIZE 20
+#define FILENT_SIZE 80
+
+#define SEND 0
+#define RECV 1
+
+#define STATE_NONE 0
+#define STATE_READY 1
+
+struct posix_msg_tree_node {
+ struct rb_node rb_node;
+ struct list_head msg_list;
+ int priority;
+};
+
+struct ext_wait_queue { /* queue of sleeping tasks */
+ struct task_struct *task;
+ struct list_head list;
+ struct msg_msg *msg; /* ptr of loaded message */
+ int state; /* one of STATE_* values */
+};
+
+struct mqueue_inode_info {
+ spinlock_t lock;
+ struct inode vfs_inode;
+ wait_queue_head_t wait_q;
+
+ struct rb_root msg_tree;
+ struct posix_msg_tree_node *node_cache;
+ struct mq_attr attr;
+
+ struct sigevent notify;
+ struct pid *notify_owner;
+ struct user_namespace *notify_user_ns;
+ struct user_struct *user; /* user who created, for accounting */
+ struct sock *notify_sock;
+ struct sk_buff *notify_cookie;
+
+ /* for tasks waiting for free space and messages, respectively */
+ struct ext_wait_queue e_wait_q[2];
+
+ unsigned long qsize; /* size of queue in memory (sum of all msgs) */
+};
+
+static const struct inode_operations mqueue_dir_inode_operations;
+static const struct file_operations mqueue_file_operations;
+static const struct super_operations mqueue_super_ops;
+static void remove_notification(struct mqueue_inode_info *info);
+
+static struct kmem_cache *mqueue_inode_cachep;
+
+static struct ctl_table_header *mq_sysctl_table;
+
+static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
+{
+ return container_of(inode, struct mqueue_inode_info, vfs_inode);
+}
+
+/*
+ * This routine should be called with the mq_lock held.
+ */
+static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
+{
+ return get_ipc_ns(inode->i_sb->s_fs_info);
+}
+
+static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
+{
+ struct ipc_namespace *ns;
+
+ spin_lock(&mq_lock);
+ ns = __get_ns_from_inode(inode);
+ spin_unlock(&mq_lock);
+ return ns;
+}
+
+/* Auxiliary functions to manipulate messages' list */
+static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
+{
+ struct rb_node **p, *parent = NULL;
+ struct posix_msg_tree_node *leaf;
+
+ p = &info->msg_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
+
+ if (likely(leaf->priority == msg->m_type))
+ goto insert_msg;
+ else if (msg->m_type < leaf->priority)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+ if (info->node_cache) {
+ leaf = info->node_cache;
+ info->node_cache = NULL;
+ } else {
+ leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
+ if (!leaf)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&leaf->msg_list);
+ }
+ leaf->priority = msg->m_type;
+ rb_link_node(&leaf->rb_node, parent, p);
+ rb_insert_color(&leaf->rb_node, &info->msg_tree);
+insert_msg:
+ info->attr.mq_curmsgs++;
+ info->qsize += msg->m_ts;
+ list_add_tail(&msg->m_list, &leaf->msg_list);
+ return 0;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+ struct rb_node **p, *parent = NULL;
+ struct posix_msg_tree_node *leaf;
+ struct msg_msg *msg;
+
+try_again:
+ p = &info->msg_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ /*
+ * During insert, low priorities go to the left and high to the
+ * right. On receive, we want the highest priorities first, so
+ * walk all the way to the right.
+ */
+ p = &(*p)->rb_right;
+ }
+ if (!parent) {
+ if (info->attr.mq_curmsgs) {
+ pr_warn_once("Inconsistency in POSIX message queue, "
+ "no tree element, but supposedly messages "
+ "should exist!\n");
+ info->attr.mq_curmsgs = 0;
+ }
+ return NULL;
+ }
+ leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
+ if (unlikely(list_empty(&leaf->msg_list))) {
+ pr_warn_once("Inconsistency in POSIX message queue, "
+ "empty leaf node but we haven't implemented "
+ "lazy leaf delete!\n");
+ rb_erase(&leaf->rb_node, &info->msg_tree);
+ if (info->node_cache) {
+ kfree(leaf);
+ } else {
+ info->node_cache = leaf;
+ }
+ goto try_again;
+ } else {
+ msg = list_first_entry(&leaf->msg_list,
+ struct msg_msg, m_list);
+ list_del(&msg->m_list);
+ if (list_empty(&leaf->msg_list)) {
+ rb_erase(&leaf->rb_node, &info->msg_tree);
+ if (info->node_cache) {
+ kfree(leaf);
+ } else {
+ info->node_cache = leaf;
+ }
+ }
+ }
+ info->attr.mq_curmsgs--;
+ info->qsize -= msg->m_ts;
+ return msg;
+}
+
+static struct inode *mqueue_get_inode(struct super_block *sb,
+ struct ipc_namespace *ipc_ns, umode_t mode,
+ struct mq_attr *attr)
+{
+ struct user_struct *u = current_user();
+ struct inode *inode;
+ int ret = -ENOMEM;
+
+ inode = new_inode(sb);
+ if (!inode)
+ goto err;
+
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
+ inode->i_mtime = inode->i_ctime = inode->i_atime = current_time(inode);
+
+ if (S_ISREG(mode)) {
+ struct mqueue_inode_info *info;
+ unsigned long mq_bytes, mq_treesize;
+
+ inode->i_fop = &mqueue_file_operations;
+ inode->i_size = FILENT_SIZE;
+ /* mqueue specific info */
+ info = MQUEUE_I(inode);
+ spin_lock_init(&info->lock);
+ init_waitqueue_head(&info->wait_q);
+ INIT_LIST_HEAD(&info->e_wait_q[0].list);
+ INIT_LIST_HEAD(&info->e_wait_q[1].list);
+ info->notify_owner = NULL;
+ info->notify_user_ns = NULL;
+ info->qsize = 0;
+ info->user = NULL; /* set when all is ok */
+ info->msg_tree = RB_ROOT;
+ info->node_cache = NULL;
+ memset(&info->attr, 0, sizeof(info->attr));
+ info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+ ipc_ns->mq_msg_default);
+ info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+ ipc_ns->mq_msgsize_default);
+ if (attr) {
+ info->attr.mq_maxmsg = attr->mq_maxmsg;
+ info->attr.mq_msgsize = attr->mq_msgsize;
+ }
+ /*
+ * We used to allocate a static array of pointers and account
+ * the size of that array as well as one msg_msg struct per
+ * possible message into the queue size. That's no longer
+ * accurate as the queue is now an rbtree and will grow and
+ * shrink depending on usage patterns. We can, however, still
+ * account one msg_msg struct per message, but the nodes are
+ * allocated depending on priority usage, and most programs
+ * only use one, or a handful, of priorities. However, since
+ * this is pinned memory, we need to assume worst case, so
+ * that means the min(mq_maxmsg, max_priorities) * struct
+ * posix_msg_tree_node.
+ */
+
+ ret = -EINVAL;
+ if (info->attr.mq_maxmsg <= 0 || info->attr.mq_msgsize <= 0)
+ goto out_inode;
+ if (capable(CAP_SYS_RESOURCE)) {
+ if (info->attr.mq_maxmsg > HARD_MSGMAX ||
+ info->attr.mq_msgsize > HARD_MSGSIZEMAX)
+ goto out_inode;
+ } else {
+ if (info->attr.mq_maxmsg > ipc_ns->mq_msg_max ||
+ info->attr.mq_msgsize > ipc_ns->mq_msgsize_max)
+ goto out_inode;
+ }
+ ret = -EOVERFLOW;
+ /* check for overflow */
+ if (info->attr.mq_msgsize > ULONG_MAX/info->attr.mq_maxmsg)
+ goto out_inode;
+ mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+ min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+ sizeof(struct posix_msg_tree_node);
+ mq_bytes = info->attr.mq_maxmsg * info->attr.mq_msgsize;
+ if (mq_bytes + mq_treesize < mq_bytes)
+ goto out_inode;
+ mq_bytes += mq_treesize;
+ spin_lock(&mq_lock);
+ if (u->mq_bytes + mq_bytes < u->mq_bytes ||
+ u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
+ spin_unlock(&mq_lock);
+ /* mqueue_evict_inode() releases info->messages */
+ ret = -EMFILE;
+ goto out_inode;
+ }
+ u->mq_bytes += mq_bytes;
+ spin_unlock(&mq_lock);
+
+ /* all is ok */
+ info->user = get_uid(u);
+ } else if (S_ISDIR(mode)) {
+ inc_nlink(inode);
+ /* Some things misbehave if size == 0 on a directory */
+ inode->i_size = 2 * DIRENT_SIZE;
+ inode->i_op = &mqueue_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ }
+
+ return inode;
+out_inode:
+ iput(inode);
+err:
+ return ERR_PTR(ret);
+}
+
+static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+ struct ipc_namespace *ns = sb->s_fs_info;
+
+ sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
+ sb->s_blocksize = PAGE_SIZE;
+ sb->s_blocksize_bits = PAGE_SHIFT;
+ sb->s_magic = MQUEUE_MAGIC;
+ sb->s_op = &mqueue_super_ops;
+
+ inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ return -ENOMEM;
+ return 0;
+}
+
+static struct dentry *mqueue_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data)
+{
+ struct ipc_namespace *ns;
+ if (flags & SB_KERNMOUNT) {
+ ns = data;
+ data = NULL;
+ } else {
+ ns = current->nsproxy->ipc_ns;
+ }
+ return mount_ns(fs_type, flags, data, ns, ns->user_ns, mqueue_fill_super);
+}
+
+static void init_once(void *foo)
+{
+ struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
+
+ inode_init_once(&p->vfs_inode);
+}
+
+static struct inode *mqueue_alloc_inode(struct super_block *sb)
+{
+ struct mqueue_inode_info *ei;
+
+ ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
+ if (!ei)
+ return NULL;
+ return &ei->vfs_inode;
+}
+
+static void mqueue_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
+}
+
+static void mqueue_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, mqueue_i_callback);
+}
+
+static void mqueue_evict_inode(struct inode *inode)
+{
+ struct mqueue_inode_info *info;
+ struct user_struct *user;
+ unsigned long mq_bytes, mq_treesize;
+ struct ipc_namespace *ipc_ns;
+ struct msg_msg *msg;
+
+ clear_inode(inode);
+
+ if (S_ISDIR(inode->i_mode))
+ return;
+
+ ipc_ns = get_ns_from_inode(inode);
+ info = MQUEUE_I(inode);
+ spin_lock(&info->lock);
+ while ((msg = msg_get(info)) != NULL)
+ free_msg(msg);
+ kfree(info->node_cache);
+ spin_unlock(&info->lock);
+
+ /* Total amount of bytes accounted for the mqueue */
+ mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+ min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+ sizeof(struct posix_msg_tree_node);
+
+ mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
+ info->attr.mq_msgsize);
+
+ user = info->user;
+ if (user) {
+ spin_lock(&mq_lock);
+ user->mq_bytes -= mq_bytes;
+ /*
+ * get_ns_from_inode() ensures that the
+ * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
+ * to which we now hold a reference, or it is NULL.
+ * We can't put it here under mq_lock, though.
+ */
+ if (ipc_ns)
+ ipc_ns->mq_queues_count--;
+ spin_unlock(&mq_lock);
+ free_uid(user);
+ }
+ if (ipc_ns)
+ put_ipc_ns(ipc_ns);
+}
+
+static int mqueue_create_attr(struct dentry *dentry, umode_t mode, void *arg)
+{
+ struct inode *dir = dentry->d_parent->d_inode;
+ struct inode *inode;
+ struct mq_attr *attr = arg;
+ int error;
+ struct ipc_namespace *ipc_ns;
+
+ spin_lock(&mq_lock);
+ ipc_ns = __get_ns_from_inode(dir);
+ if (!ipc_ns) {
+ error = -EACCES;
+ goto out_unlock;
+ }
+
+ if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
+ !capable(CAP_SYS_RESOURCE)) {
+ error = -ENOSPC;
+ goto out_unlock;
+ }
+ ipc_ns->mq_queues_count++;
+ spin_unlock(&mq_lock);
+
+ inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
+ if (IS_ERR(inode)) {
+ error = PTR_ERR(inode);
+ spin_lock(&mq_lock);
+ ipc_ns->mq_queues_count--;
+ goto out_unlock;
+ }
+
+ put_ipc_ns(ipc_ns);
+ dir->i_size += DIRENT_SIZE;
+ dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
+
+ d_instantiate(dentry, inode);
+ dget(dentry);
+ return 0;
+out_unlock:
+ spin_unlock(&mq_lock);
+ if (ipc_ns)
+ put_ipc_ns(ipc_ns);
+ return error;
+}
+
+static int mqueue_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, bool excl)
+{
+ return mqueue_create_attr(dentry, mode, NULL);
+}
+
+static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+
+ dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
+ dir->i_size -= DIRENT_SIZE;
+ drop_nlink(inode);
+ dput(dentry);
+ return 0;
+}
+
+/*
+* This is routine for system read from queue file.
+* To avoid mess with doing here some sort of mq_receive we allow
+* to read only queue size & notification info (the only values
+* that are interesting from user point of view and aren't accessible
+* through std routines)
+*/
+static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
+ size_t count, loff_t *off)
+{
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
+ char buffer[FILENT_SIZE];
+ ssize_t ret;
+
+ spin_lock(&info->lock);
+ snprintf(buffer, sizeof(buffer),
+ "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
+ info->qsize,
+ info->notify_owner ? info->notify.sigev_notify : 0,
+ (info->notify_owner &&
+ info->notify.sigev_notify == SIGEV_SIGNAL) ?
+ info->notify.sigev_signo : 0,
+ pid_vnr(info->notify_owner));
+ spin_unlock(&info->lock);
+ buffer[sizeof(buffer)-1] = '\0';
+
+ ret = simple_read_from_buffer(u_data, count, off, buffer,
+ strlen(buffer));
+ if (ret <= 0)
+ return ret;
+
+ file_inode(filp)->i_atime = file_inode(filp)->i_ctime = current_time(file_inode(filp));
+ return ret;
+}
+
+static int mqueue_flush_file(struct file *filp, fl_owner_t id)
+{
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
+
+ spin_lock(&info->lock);
+ if (task_tgid(current) == info->notify_owner)
+ remove_notification(info);
+
+ spin_unlock(&info->lock);
+ return 0;
+}
+
+static __poll_t mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
+{
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
+ __poll_t retval = 0;
+
+ poll_wait(filp, &info->wait_q, poll_tab);
+
+ spin_lock(&info->lock);
+ if (info->attr.mq_curmsgs)
+ retval = EPOLLIN | EPOLLRDNORM;
+
+ if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
+ retval |= EPOLLOUT | EPOLLWRNORM;
+ spin_unlock(&info->lock);
+
+ return retval;
+}
+
+/* Adds current to info->e_wait_q[sr] before element with smaller prio */
+static void wq_add(struct mqueue_inode_info *info, int sr,
+ struct ext_wait_queue *ewp)
+{
+ struct ext_wait_queue *walk;
+
+ ewp->task = current;
+
+ list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
+ if (walk->task->prio <= current->prio) {
+ list_add_tail(&ewp->list, &walk->list);
+ return;
+ }
+ }
+ list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
+}
+
+/*
+ * Puts current task to sleep. Caller must hold queue lock. After return
+ * lock isn't held.
+ * sr: SEND or RECV
+ */
+static int wq_sleep(struct mqueue_inode_info *info, int sr,
+ ktime_t *timeout, struct ext_wait_queue *ewp)
+ __releases(&info->lock)
+{
+ int retval;
+ signed long time;
+
+ wq_add(info, sr, ewp);
+
+ for (;;) {
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ spin_unlock(&info->lock);
+ time = schedule_hrtimeout_range_clock(timeout, 0,
+ HRTIMER_MODE_ABS, CLOCK_REALTIME);
+
+ if (ewp->state == STATE_READY) {
+ retval = 0;
+ goto out;
+ }
+ spin_lock(&info->lock);
+ if (ewp->state == STATE_READY) {
+ retval = 0;
+ goto out_unlock;
+ }
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+ if (time == 0) {
+ retval = -ETIMEDOUT;
+ break;
+ }
+ }
+ list_del(&ewp->list);
+out_unlock:
+ spin_unlock(&info->lock);
+out:
+ return retval;
+}
+
+/*
+ * Returns waiting task that should be serviced first or NULL if none exists
+ */
+static struct ext_wait_queue *wq_get_first_waiter(
+ struct mqueue_inode_info *info, int sr)
+{
+ struct list_head *ptr;
+
+ ptr = info->e_wait_q[sr].list.prev;
+ if (ptr == &info->e_wait_q[sr].list)
+ return NULL;
+ return list_entry(ptr, struct ext_wait_queue, list);
+}
+
+
+static inline void set_cookie(struct sk_buff *skb, char code)
+{
+ ((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
+}
+
+/*
+ * The next function is only to split too long sys_mq_timedsend
+ */
+static void __do_notify(struct mqueue_inode_info *info)
+{
+ /* notification
+ * invoked when there is registered process and there isn't process
+ * waiting synchronously for message AND state of queue changed from
+ * empty to not empty. Here we are sure that no one is waiting
+ * synchronously. */
+ if (info->notify_owner &&
+ info->attr.mq_curmsgs == 1) {
+ struct siginfo sig_i;
+ switch (info->notify.sigev_notify) {
+ case SIGEV_NONE:
+ break;
+ case SIGEV_SIGNAL:
+ /* sends signal */
+
+ clear_siginfo(&sig_i);
+ sig_i.si_signo = info->notify.sigev_signo;
+ sig_i.si_errno = 0;
+ sig_i.si_code = SI_MESGQ;
+ sig_i.si_value = info->notify.sigev_value;
+ /* map current pid/uid into info->owner's namespaces */
+ rcu_read_lock();
+ sig_i.si_pid = task_tgid_nr_ns(current,
+ ns_of_pid(info->notify_owner));
+ sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid());
+ rcu_read_unlock();
+
+ kill_pid_info(info->notify.sigev_signo,
+ &sig_i, info->notify_owner);
+ break;
+ case SIGEV_THREAD:
+ set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
+ netlink_sendskb(info->notify_sock, info->notify_cookie);
+ break;
+ }
+ /* after notification unregisters process */
+ put_pid(info->notify_owner);
+ put_user_ns(info->notify_user_ns);
+ info->notify_owner = NULL;
+ info->notify_user_ns = NULL;
+ }
+ wake_up(&info->wait_q);
+}
+
+static int prepare_timeout(const struct __kernel_timespec __user *u_abs_timeout,
+ struct timespec64 *ts)
+{
+ if (get_timespec64(ts, u_abs_timeout))
+ return -EFAULT;
+ if (!timespec64_valid(ts))
+ return -EINVAL;
+ return 0;
+}
+
+static void remove_notification(struct mqueue_inode_info *info)
+{
+ if (info->notify_owner != NULL &&
+ info->notify.sigev_notify == SIGEV_THREAD) {
+ set_cookie(info->notify_cookie, NOTIFY_REMOVED);
+ netlink_sendskb(info->notify_sock, info->notify_cookie);
+ }
+ put_pid(info->notify_owner);
+ put_user_ns(info->notify_user_ns);
+ info->notify_owner = NULL;
+ info->notify_user_ns = NULL;
+}
+
+static int prepare_open(struct dentry *dentry, int oflag, int ro,
+ umode_t mode, struct filename *name,
+ struct mq_attr *attr)
+{
+ static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
+ MAY_READ | MAY_WRITE };
+ int acc;
+
+ if (d_really_is_negative(dentry)) {
+ if (!(oflag & O_CREAT))
+ return -ENOENT;
+ if (ro)
+ return ro;
+ audit_inode_parent_hidden(name, dentry->d_parent);
+ return vfs_mkobj(dentry, mode & ~current_umask(),
+ mqueue_create_attr, attr);
+ }
+ /* it already existed */
+ audit_inode(name, dentry, 0);
+ if ((oflag & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+ return -EEXIST;
+ if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
+ return -EINVAL;
+ acc = oflag2acc[oflag & O_ACCMODE];
+ return inode_permission(d_inode(dentry), acc);
+}
+
+static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
+ struct mq_attr *attr)
+{
+ struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt;
+ struct dentry *root = mnt->mnt_root;
+ struct filename *name;
+ struct path path;
+ int fd, error;
+ int ro;
+
+ audit_mq_open(oflag, mode, attr);
+
+ if (IS_ERR(name = getname(u_name)))
+ return PTR_ERR(name);
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ goto out_putname;
+
+ ro = mnt_want_write(mnt); /* we'll drop it in any case */
+ inode_lock(d_inode(root));
+ path.dentry = lookup_one_len(name->name, root, strlen(name->name));
+ if (IS_ERR(path.dentry)) {
+ error = PTR_ERR(path.dentry);
+ goto out_putfd;
+ }
+ path.mnt = mntget(mnt);
+ error = prepare_open(path.dentry, oflag, ro, mode, name, attr);
+ if (!error) {
+ struct file *file = dentry_open(&path, oflag, current_cred());
+ if (!IS_ERR(file))
+ fd_install(fd, file);
+ else
+ error = PTR_ERR(file);
+ }
+ path_put(&path);
+out_putfd:
+ if (error) {
+ put_unused_fd(fd);
+ fd = error;
+ }
+ inode_unlock(d_inode(root));
+ if (!ro)
+ mnt_drop_write(mnt);
+out_putname:
+ putname(name);
+ return fd;
+}
+
+SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
+ struct mq_attr __user *, u_attr)
+{
+ struct mq_attr attr;
+ if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
+ return -EFAULT;
+
+ return do_mq_open(u_name, oflag, mode, u_attr ? &attr : NULL);
+}
+
+SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
+{
+ int err;
+ struct filename *name;
+ struct dentry *dentry;
+ struct inode *inode = NULL;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ struct vfsmount *mnt = ipc_ns->mq_mnt;
+
+ name = getname(u_name);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ audit_inode_parent_hidden(name, mnt->mnt_root);
+ err = mnt_want_write(mnt);
+ if (err)
+ goto out_name;
+ inode_lock_nested(d_inode(mnt->mnt_root), I_MUTEX_PARENT);
+ dentry = lookup_one_len(name->name, mnt->mnt_root,
+ strlen(name->name));
+ if (IS_ERR(dentry)) {
+ err = PTR_ERR(dentry);
+ goto out_unlock;
+ }
+
+ inode = d_inode(dentry);
+ if (!inode) {
+ err = -ENOENT;
+ } else {
+ ihold(inode);
+ err = vfs_unlink(d_inode(dentry->d_parent), dentry, NULL);
+ }
+ dput(dentry);
+
+out_unlock:
+ inode_unlock(d_inode(mnt->mnt_root));
+ if (inode)
+ iput(inode);
+ mnt_drop_write(mnt);
+out_name:
+ putname(name);
+
+ return err;
+}
+
+/* Pipelined send and receive functions.
+ *
+ * If a receiver finds no waiting message, then it registers itself in the
+ * list of waiting receivers. A sender checks that list before adding the new
+ * message into the message array. If there is a waiting receiver, then it
+ * bypasses the message array and directly hands the message over to the
+ * receiver. The receiver accepts the message and returns without grabbing the
+ * queue spinlock:
+ *
+ * - Set pointer to message.
+ * - Queue the receiver task for later wakeup (without the info->lock).
+ * - Update its state to STATE_READY. Now the receiver can continue.
+ * - Wake up the process after the lock is dropped. Should the process wake up
+ * before this wakeup (due to a timeout or a signal) it will either see
+ * STATE_READY and continue or acquire the lock to check the state again.
+ *
+ * The same algorithm is used for senders.
+ */
+
+/* pipelined_send() - send a message directly to the task waiting in
+ * sys_mq_timedreceive() (without inserting message into a queue).
+ */
+static inline void pipelined_send(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info,
+ struct msg_msg *message,
+ struct ext_wait_queue *receiver)
+{
+ receiver->msg = message;
+ list_del(&receiver->list);
+ wake_q_add(wake_q, receiver->task);
+ /*
+ * Rely on the implicit cmpxchg barrier from wake_q_add such
+ * that we can ensure that updating receiver->state is the last
+ * write operation: As once set, the receiver can continue,
+ * and if we don't have the reference count from the wake_q,
+ * yet, at that point we can later have a use-after-free
+ * condition and bogus wakeup.
+ */
+ receiver->state = STATE_READY;
+}
+
+/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
+ * gets its message and put to the queue (we have one free place for sure). */
+static inline void pipelined_receive(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info)
+{
+ struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
+
+ if (!sender) {
+ /* for poll */
+ wake_up_interruptible(&info->wait_q);
+ return;
+ }
+ if (msg_insert(sender->msg, info))
+ return;
+
+ list_del(&sender->list);
+ wake_q_add(wake_q, sender->task);
+ sender->state = STATE_READY;
+}
+
+static int do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+ size_t msg_len, unsigned int msg_prio,
+ struct timespec64 *ts)
+{
+ struct fd f;
+ struct inode *inode;
+ struct ext_wait_queue wait;
+ struct ext_wait_queue *receiver;
+ struct msg_msg *msg_ptr;
+ struct mqueue_inode_info *info;
+ ktime_t expires, *timeout = NULL;
+ struct posix_msg_tree_node *new_leaf = NULL;
+ int ret = 0;
+ DEFINE_WAKE_Q(wake_q);
+
+ if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
+ return -EINVAL;
+
+ if (ts) {
+ expires = timespec64_to_ktime(*ts);
+ timeout = &expires;
+ }
+
+ audit_mq_sendrecv(mqdes, msg_len, msg_prio, ts);
+
+ f = fdget(mqdes);
+ if (unlikely(!f.file)) {
+ ret = -EBADF;
+ goto out;
+ }
+
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
+ goto out_fput;
+ }
+ info = MQUEUE_I(inode);
+ audit_file(f.file);
+
+ if (unlikely(!(f.file->f_mode & FMODE_WRITE))) {
+ ret = -EBADF;
+ goto out_fput;
+ }
+
+ if (unlikely(msg_len > info->attr.mq_msgsize)) {
+ ret = -EMSGSIZE;
+ goto out_fput;
+ }
+
+ /* First try to allocate memory, before doing anything with
+ * existing queues. */
+ msg_ptr = load_msg(u_msg_ptr, msg_len);
+ if (IS_ERR(msg_ptr)) {
+ ret = PTR_ERR(msg_ptr);
+ goto out_fput;
+ }
+ msg_ptr->m_ts = msg_len;
+ msg_ptr->m_type = msg_prio;
+
+ /*
+ * msg_insert really wants us to have a valid, spare node struct so
+ * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
+ * fall back to that if necessary.
+ */
+ if (!info->node_cache)
+ new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
+
+ spin_lock(&info->lock);
+
+ if (!info->node_cache && new_leaf) {
+ /* Save our speculative allocation into the cache */
+ INIT_LIST_HEAD(&new_leaf->msg_list);
+ info->node_cache = new_leaf;
+ new_leaf = NULL;
+ } else {
+ kfree(new_leaf);
+ }
+
+ if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
+ if (f.file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ } else {
+ wait.task = current;
+ wait.msg = (void *) msg_ptr;
+ wait.state = STATE_NONE;
+ ret = wq_sleep(info, SEND, timeout, &wait);
+ /*
+ * wq_sleep must be called with info->lock held, and
+ * returns with the lock released
+ */
+ goto out_free;
+ }
+ } else {
+ receiver = wq_get_first_waiter(info, RECV);
+ if (receiver) {
+ pipelined_send(&wake_q, info, msg_ptr, receiver);
+ } else {
+ /* adds message to the queue */
+ ret = msg_insert(msg_ptr, info);
+ if (ret)
+ goto out_unlock;
+ __do_notify(info);
+ }
+ inode->i_atime = inode->i_mtime = inode->i_ctime =
+ current_time(inode);
+ }
+out_unlock:
+ spin_unlock(&info->lock);
+ wake_up_q(&wake_q);
+out_free:
+ if (ret)
+ free_msg(msg_ptr);
+out_fput:
+ fdput(f);
+out:
+ return ret;
+}
+
+static int do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+ size_t msg_len, unsigned int __user *u_msg_prio,
+ struct timespec64 *ts)
+{
+ ssize_t ret;
+ struct msg_msg *msg_ptr;
+ struct fd f;
+ struct inode *inode;
+ struct mqueue_inode_info *info;
+ struct ext_wait_queue wait;
+ ktime_t expires, *timeout = NULL;
+ struct posix_msg_tree_node *new_leaf = NULL;
+
+ if (ts) {
+ expires = timespec64_to_ktime(*ts);
+ timeout = &expires;
+ }
+
+ audit_mq_sendrecv(mqdes, msg_len, 0, ts);
+
+ f = fdget(mqdes);
+ if (unlikely(!f.file)) {
+ ret = -EBADF;
+ goto out;
+ }
+
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
+ goto out_fput;
+ }
+ info = MQUEUE_I(inode);
+ audit_file(f.file);
+
+ if (unlikely(!(f.file->f_mode & FMODE_READ))) {
+ ret = -EBADF;
+ goto out_fput;
+ }
+
+ /* checks if buffer is big enough */
+ if (unlikely(msg_len < info->attr.mq_msgsize)) {
+ ret = -EMSGSIZE;
+ goto out_fput;
+ }
+
+ /*
+ * msg_insert really wants us to have a valid, spare node struct so
+ * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
+ * fall back to that if necessary.
+ */
+ if (!info->node_cache)
+ new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
+
+ spin_lock(&info->lock);
+
+ if (!info->node_cache && new_leaf) {
+ /* Save our speculative allocation into the cache */
+ INIT_LIST_HEAD(&new_leaf->msg_list);
+ info->node_cache = new_leaf;
+ } else {
+ kfree(new_leaf);
+ }
+
+ if (info->attr.mq_curmsgs == 0) {
+ if (f.file->f_flags & O_NONBLOCK) {
+ spin_unlock(&info->lock);
+ ret = -EAGAIN;
+ } else {
+ wait.task = current;
+ wait.state = STATE_NONE;
+ ret = wq_sleep(info, RECV, timeout, &wait);
+ msg_ptr = wait.msg;
+ }
+ } else {
+ DEFINE_WAKE_Q(wake_q);
+
+ msg_ptr = msg_get(info);
+
+ inode->i_atime = inode->i_mtime = inode->i_ctime =
+ current_time(inode);
+
+ /* There is now free space in queue. */
+ pipelined_receive(&wake_q, info);
+ spin_unlock(&info->lock);
+ wake_up_q(&wake_q);
+ ret = 0;
+ }
+ if (ret == 0) {
+ ret = msg_ptr->m_ts;
+
+ if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
+ store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
+ ret = -EFAULT;
+ }
+ free_msg(msg_ptr);
+ }
+out_fput:
+ fdput(f);
+out:
+ return ret;
+}
+
+SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
+ size_t, msg_len, unsigned int, msg_prio,
+ const struct __kernel_timespec __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
+}
+
+SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
+ size_t, msg_len, unsigned int __user *, u_msg_prio,
+ const struct __kernel_timespec __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p);
+}
+
+/*
+ * Notes: the case when user wants us to deregister (with NULL as pointer)
+ * and he isn't currently owner of notification, will be silently discarded.
+ * It isn't explicitly defined in the POSIX.
+ */
+static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification)
+{
+ int ret;
+ struct fd f;
+ struct sock *sock;
+ struct inode *inode;
+ struct mqueue_inode_info *info;
+ struct sk_buff *nc;
+
+ audit_mq_notify(mqdes, notification);
+
+ nc = NULL;
+ sock = NULL;
+ if (notification != NULL) {
+ if (unlikely(notification->sigev_notify != SIGEV_NONE &&
+ notification->sigev_notify != SIGEV_SIGNAL &&
+ notification->sigev_notify != SIGEV_THREAD))
+ return -EINVAL;
+ if (notification->sigev_notify == SIGEV_SIGNAL &&
+ !valid_signal(notification->sigev_signo)) {
+ return -EINVAL;
+ }
+ if (notification->sigev_notify == SIGEV_THREAD) {
+ long timeo;
+
+ /* create the notify skb */
+ nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
+ if (!nc) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (copy_from_user(nc->data,
+ notification->sigev_value.sival_ptr,
+ NOTIFY_COOKIE_LEN)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ /* TODO: add a header? */
+ skb_put(nc, NOTIFY_COOKIE_LEN);
+ /* and attach it to the socket */
+retry:
+ f = fdget(notification->sigev_signo);
+ if (!f.file) {
+ ret = -EBADF;
+ goto out;
+ }
+ sock = netlink_getsockbyfilp(f.file);
+ fdput(f);
+ if (IS_ERR(sock)) {
+ ret = PTR_ERR(sock);
+ sock = NULL;
+ goto out;
+ }
+
+ timeo = MAX_SCHEDULE_TIMEOUT;
+ ret = netlink_attachskb(sock, nc, &timeo, NULL);
+ if (ret == 1) {
+ sock = NULL;
+ goto retry;
+ }
+ if (ret) {
+ sock = NULL;
+ nc = NULL;
+ goto out;
+ }
+ }
+ }
+
+ f = fdget(mqdes);
+ if (!f.file) {
+ ret = -EBADF;
+ goto out;
+ }
+
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
+ goto out_fput;
+ }
+ info = MQUEUE_I(inode);
+
+ ret = 0;
+ spin_lock(&info->lock);
+ if (notification == NULL) {
+ if (info->notify_owner == task_tgid(current)) {
+ remove_notification(info);
+ inode->i_atime = inode->i_ctime = current_time(inode);
+ }
+ } else if (info->notify_owner != NULL) {
+ ret = -EBUSY;
+ } else {
+ switch (notification->sigev_notify) {
+ case SIGEV_NONE:
+ info->notify.sigev_notify = SIGEV_NONE;
+ break;
+ case SIGEV_THREAD:
+ info->notify_sock = sock;
+ info->notify_cookie = nc;
+ sock = NULL;
+ nc = NULL;
+ info->notify.sigev_notify = SIGEV_THREAD;
+ break;
+ case SIGEV_SIGNAL:
+ info->notify.sigev_signo = notification->sigev_signo;
+ info->notify.sigev_value = notification->sigev_value;
+ info->notify.sigev_notify = SIGEV_SIGNAL;
+ break;
+ }
+
+ info->notify_owner = get_pid(task_tgid(current));
+ info->notify_user_ns = get_user_ns(current_user_ns());
+ inode->i_atime = inode->i_ctime = current_time(inode);
+ }
+ spin_unlock(&info->lock);
+out_fput:
+ fdput(f);
+out:
+ if (sock)
+ netlink_detachskb(sock, nc);
+ else if (nc)
+ dev_kfree_skb(nc);
+
+ return ret;
+}
+
+SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
+ const struct sigevent __user *, u_notification)
+{
+ struct sigevent n, *p = NULL;
+ if (u_notification) {
+ if (copy_from_user(&n, u_notification, sizeof(struct sigevent)))
+ return -EFAULT;
+ p = &n;
+ }
+ return do_mq_notify(mqdes, p);
+}
+
+static int do_mq_getsetattr(int mqdes, struct mq_attr *new, struct mq_attr *old)
+{
+ struct fd f;
+ struct inode *inode;
+ struct mqueue_inode_info *info;
+
+ if (new && (new->mq_flags & (~O_NONBLOCK)))
+ return -EINVAL;
+
+ f = fdget(mqdes);
+ if (!f.file)
+ return -EBADF;
+
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ fdput(f);
+ return -EBADF;
+ }
+
+ inode = file_inode(f.file);
+ info = MQUEUE_I(inode);
+
+ spin_lock(&info->lock);
+
+ if (old) {
+ *old = info->attr;
+ old->mq_flags = f.file->f_flags & O_NONBLOCK;
+ }
+ if (new) {
+ audit_mq_getsetattr(mqdes, new);
+ spin_lock(&f.file->f_lock);
+ if (new->mq_flags & O_NONBLOCK)
+ f.file->f_flags |= O_NONBLOCK;
+ else
+ f.file->f_flags &= ~O_NONBLOCK;
+ spin_unlock(&f.file->f_lock);
+
+ inode->i_atime = inode->i_ctime = current_time(inode);
+ }
+
+ spin_unlock(&info->lock);
+ fdput(f);
+ return 0;
+}
+
+SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
+ const struct mq_attr __user *, u_mqstat,
+ struct mq_attr __user *, u_omqstat)
+{
+ int ret;
+ struct mq_attr mqstat, omqstat;
+ struct mq_attr *new = NULL, *old = NULL;
+
+ if (u_mqstat) {
+ new = &mqstat;
+ if (copy_from_user(new, u_mqstat, sizeof(struct mq_attr)))
+ return -EFAULT;
+ }
+ if (u_omqstat)
+ old = &omqstat;
+
+ ret = do_mq_getsetattr(mqdes, new, old);
+ if (ret || !old)
+ return ret;
+
+ if (copy_to_user(u_omqstat, old, sizeof(struct mq_attr)))
+ return -EFAULT;
+ return 0;
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_mq_attr {
+ compat_long_t mq_flags; /* message queue flags */
+ compat_long_t mq_maxmsg; /* maximum number of messages */
+ compat_long_t mq_msgsize; /* maximum message size */
+ compat_long_t mq_curmsgs; /* number of messages currently queued */
+ compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
+};
+
+static inline int get_compat_mq_attr(struct mq_attr *attr,
+ const struct compat_mq_attr __user *uattr)
+{
+ struct compat_mq_attr v;
+
+ if (copy_from_user(&v, uattr, sizeof(*uattr)))
+ return -EFAULT;
+
+ memset(attr, 0, sizeof(*attr));
+ attr->mq_flags = v.mq_flags;
+ attr->mq_maxmsg = v.mq_maxmsg;
+ attr->mq_msgsize = v.mq_msgsize;
+ attr->mq_curmsgs = v.mq_curmsgs;
+ return 0;
+}
+
+static inline int put_compat_mq_attr(const struct mq_attr *attr,
+ struct compat_mq_attr __user *uattr)
+{
+ struct compat_mq_attr v;
+
+ memset(&v, 0, sizeof(v));
+ v.mq_flags = attr->mq_flags;
+ v.mq_maxmsg = attr->mq_maxmsg;
+ v.mq_msgsize = attr->mq_msgsize;
+ v.mq_curmsgs = attr->mq_curmsgs;
+ if (copy_to_user(uattr, &v, sizeof(*uattr)))
+ return -EFAULT;
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
+ int, oflag, compat_mode_t, mode,
+ struct compat_mq_attr __user *, u_attr)
+{
+ struct mq_attr attr, *p = NULL;
+ if (u_attr && oflag & O_CREAT) {
+ p = &attr;
+ if (get_compat_mq_attr(&attr, u_attr))
+ return -EFAULT;
+ }
+ return do_mq_open(u_name, oflag, mode, p);
+}
+
+COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
+ const struct compat_sigevent __user *, u_notification)
+{
+ struct sigevent n, *p = NULL;
+ if (u_notification) {
+ if (get_compat_sigevent(&n, u_notification))
+ return -EFAULT;
+ if (n.sigev_notify == SIGEV_THREAD)
+ n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
+ p = &n;
+ }
+ return do_mq_notify(mqdes, p);
+}
+
+COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
+ const struct compat_mq_attr __user *, u_mqstat,
+ struct compat_mq_attr __user *, u_omqstat)
+{
+ int ret;
+ struct mq_attr mqstat, omqstat;
+ struct mq_attr *new = NULL, *old = NULL;
+
+ if (u_mqstat) {
+ new = &mqstat;
+ if (get_compat_mq_attr(new, u_mqstat))
+ return -EFAULT;
+ }
+ if (u_omqstat)
+ old = &omqstat;
+
+ ret = do_mq_getsetattr(mqdes, new, old);
+ if (ret || !old)
+ return ret;
+
+ if (put_compat_mq_attr(old, u_omqstat))
+ return -EFAULT;
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+static int compat_prepare_timeout(const struct compat_timespec __user *p,
+ struct timespec64 *ts)
+{
+ if (compat_get_timespec64(ts, p))
+ return -EFAULT;
+ if (!timespec64_valid(ts))
+ return -EINVAL;
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes,
+ const char __user *, u_msg_ptr,
+ compat_size_t, msg_len, unsigned int, msg_prio,
+ const struct compat_timespec __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = compat_prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
+}
+
+COMPAT_SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes,
+ char __user *, u_msg_ptr,
+ compat_size_t, msg_len, unsigned int __user *, u_msg_prio,
+ const struct compat_timespec __user *, u_abs_timeout)
+{
+ struct timespec64 ts, *p = NULL;
+ if (u_abs_timeout) {
+ int res = compat_prepare_timeout(u_abs_timeout, &ts);
+ if (res)
+ return res;
+ p = &ts;
+ }
+ return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p);
+}
+#endif
+
+static const struct inode_operations mqueue_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .create = mqueue_create,
+ .unlink = mqueue_unlink,
+};
+
+static const struct file_operations mqueue_file_operations = {
+ .flush = mqueue_flush_file,
+ .poll = mqueue_poll_file,
+ .read = mqueue_read_file,
+ .llseek = default_llseek,
+};
+
+static const struct super_operations mqueue_super_ops = {
+ .alloc_inode = mqueue_alloc_inode,
+ .destroy_inode = mqueue_destroy_inode,
+ .evict_inode = mqueue_evict_inode,
+ .statfs = simple_statfs,
+};
+
+static struct file_system_type mqueue_fs_type = {
+ .name = "mqueue",
+ .mount = mqueue_mount,
+ .kill_sb = kill_litter_super,
+ .fs_flags = FS_USERNS_MOUNT,
+};
+
+int mq_init_ns(struct ipc_namespace *ns)
+{
+ ns->mq_queues_count = 0;
+ ns->mq_queues_max = DFLT_QUEUESMAX;
+ ns->mq_msg_max = DFLT_MSGMAX;
+ ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
+ ns->mq_msg_default = DFLT_MSG;
+ ns->mq_msgsize_default = DFLT_MSGSIZE;
+
+ ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
+ if (IS_ERR(ns->mq_mnt)) {
+ int err = PTR_ERR(ns->mq_mnt);
+ ns->mq_mnt = NULL;
+ return err;
+ }
+ return 0;
+}
+
+void mq_clear_sbinfo(struct ipc_namespace *ns)
+{
+ ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+}
+
+void mq_put_mnt(struct ipc_namespace *ns)
+{
+ kern_unmount(ns->mq_mnt);
+}
+
+static int __init init_mqueue_fs(void)
+{
+ int error;
+
+ mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
+ sizeof(struct mqueue_inode_info), 0,
+ SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, init_once);
+ if (mqueue_inode_cachep == NULL)
+ return -ENOMEM;
+
+ /* ignore failures - they are not fatal */
+ mq_sysctl_table = mq_register_sysctl_table();
+
+ error = register_filesystem(&mqueue_fs_type);
+ if (error)
+ goto out_sysctl;
+
+ spin_lock_init(&mq_lock);
+
+ error = mq_init_ns(&init_ipc_ns);
+ if (error)
+ goto out_filesystem;
+
+ return 0;
+
+out_filesystem:
+ unregister_filesystem(&mqueue_fs_type);
+out_sysctl:
+ if (mq_sysctl_table)
+ unregister_sysctl_table(mq_sysctl_table);
+ kmem_cache_destroy(mqueue_inode_cachep);
+ return error;
+}
+
+device_initcall(init_mqueue_fs);
diff --git a/ipc/msg.c b/ipc/msg.c
new file mode 100644
index 0000000..883642c
--- /dev/null
+++ b/ipc/msg.c
@@ -0,0 +1,1297 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/ipc/msg.c
+ * Copyright (C) 1992 Krishna Balasubramanian
+ *
+ * Removed all the remaining kerneld mess
+ * Catch the -EFAULT stuff properly
+ * Use GFP_KERNEL for messages as in 1.2
+ * Fixed up the unchecked user space derefs
+ * Copyright (C) 1998 Alan Cox & Andi Kleen
+ *
+ * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
+ *
+ * mostly rewritten, threaded and wake-one semantics added
+ * MSGMAX limit removed, sysctl's added
+ * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
+ *
+ * support for audit of ipc object properties and permission changes
+ * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ *
+ * namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ */
+
+#include <linux/capability.h>
+#include <linux/msg.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/proc_fs.h>
+#include <linux/list.h>
+#include <linux/security.h>
+#include <linux/sched/wake_q.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <linux/seq_file.h>
+#include <linux/rwsem.h>
+#include <linux/nsproxy.h>
+#include <linux/ipc_namespace.h>
+#include <linux/rhashtable.h>
+
+#include <asm/current.h>
+#include <linux/uaccess.h>
+#include "util.h"
+
+/* one msq_queue structure for each present queue on the system */
+struct msg_queue {
+ struct kern_ipc_perm q_perm;
+ time64_t q_stime; /* last msgsnd time */
+ time64_t q_rtime; /* last msgrcv time */
+ time64_t q_ctime; /* last change time */
+ unsigned long q_cbytes; /* current number of bytes on queue */
+ unsigned long q_qnum; /* number of messages in queue */
+ unsigned long q_qbytes; /* max number of bytes on queue */
+ struct pid *q_lspid; /* pid of last msgsnd */
+ struct pid *q_lrpid; /* last receive pid */
+
+ struct list_head q_messages;
+ struct list_head q_receivers;
+ struct list_head q_senders;
+} __randomize_layout;
+
+/* one msg_receiver structure for each sleeping receiver */
+struct msg_receiver {
+ struct list_head r_list;
+ struct task_struct *r_tsk;
+
+ int r_mode;
+ long r_msgtype;
+ long r_maxsize;
+
+ struct msg_msg *r_msg;
+};
+
+/* one msg_sender for each sleeping sender */
+struct msg_sender {
+ struct list_head list;
+ struct task_struct *tsk;
+ size_t msgsz;
+};
+
+#define SEARCH_ANY 1
+#define SEARCH_EQUAL 2
+#define SEARCH_NOTEQUAL 3
+#define SEARCH_LESSEQUAL 4
+#define SEARCH_NUMBER 5
+
+#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
+
+static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&msg_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
+
+ return container_of(ipcp, struct msg_queue, q_perm);
+}
+
+static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
+
+ return container_of(ipcp, struct msg_queue, q_perm);
+}
+
+static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
+{
+ ipc_rmid(&msg_ids(ns), &s->q_perm);
+}
+
+static void msg_rcu_free(struct rcu_head *head)
+{
+ struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
+ struct msg_queue *msq = container_of(p, struct msg_queue, q_perm);
+
+ security_msg_queue_free(&msq->q_perm);
+ kvfree(msq);
+}
+
+/**
+ * newque - Create a new msg queue
+ * @ns: namespace
+ * @params: ptr to the structure that contains the key and msgflg
+ *
+ * Called with msg_ids.rwsem held (writer)
+ */
+static int newque(struct ipc_namespace *ns, struct ipc_params *params)
+{
+ struct msg_queue *msq;
+ int retval;
+ key_t key = params->key;
+ int msgflg = params->flg;
+
+ msq = kvmalloc(sizeof(*msq), GFP_KERNEL);
+ if (unlikely(!msq))
+ return -ENOMEM;
+
+ msq->q_perm.mode = msgflg & S_IRWXUGO;
+ msq->q_perm.key = key;
+
+ msq->q_perm.security = NULL;
+ retval = security_msg_queue_alloc(&msq->q_perm);
+ if (retval) {
+ kvfree(msq);
+ return retval;
+ }
+
+ msq->q_stime = msq->q_rtime = 0;
+ msq->q_ctime = ktime_get_real_seconds();
+ msq->q_cbytes = msq->q_qnum = 0;
+ msq->q_qbytes = ns->msg_ctlmnb;
+ msq->q_lspid = msq->q_lrpid = NULL;
+ INIT_LIST_HEAD(&msq->q_messages);
+ INIT_LIST_HEAD(&msq->q_receivers);
+ INIT_LIST_HEAD(&msq->q_senders);
+
+ /* ipc_addid() locks msq upon success. */
+ retval = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
+ if (retval < 0) {
+ ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
+ return retval;
+ }
+
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
+
+ return msq->q_perm.id;
+}
+
+static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz)
+{
+ return msgsz + msq->q_cbytes <= msq->q_qbytes &&
+ 1 + msq->q_qnum <= msq->q_qbytes;
+}
+
+static inline void ss_add(struct msg_queue *msq,
+ struct msg_sender *mss, size_t msgsz)
+{
+ mss->tsk = current;
+ mss->msgsz = msgsz;
+ __set_current_state(TASK_INTERRUPTIBLE);
+ list_add_tail(&mss->list, &msq->q_senders);
+}
+
+static inline void ss_del(struct msg_sender *mss)
+{
+ if (mss->list.next)
+ list_del(&mss->list);
+}
+
+static void ss_wakeup(struct msg_queue *msq,
+ struct wake_q_head *wake_q, bool kill)
+{
+ struct msg_sender *mss, *t;
+ struct task_struct *stop_tsk = NULL;
+ struct list_head *h = &msq->q_senders;
+
+ list_for_each_entry_safe(mss, t, h, list) {
+ if (kill)
+ mss->list.next = NULL;
+
+ /*
+ * Stop at the first task we don't wakeup,
+ * we've already iterated the original
+ * sender queue.
+ */
+ else if (stop_tsk == mss->tsk)
+ break;
+ /*
+ * We are not in an EIDRM scenario here, therefore
+ * verify that we really need to wakeup the task.
+ * To maintain current semantics and wakeup order,
+ * move the sender to the tail on behalf of the
+ * blocked task.
+ */
+ else if (!msg_fits_inqueue(msq, mss->msgsz)) {
+ if (!stop_tsk)
+ stop_tsk = mss->tsk;
+
+ list_move_tail(&mss->list, &msq->q_senders);
+ continue;
+ }
+
+ wake_q_add(wake_q, mss->tsk);
+ }
+}
+
+static void expunge_all(struct msg_queue *msq, int res,
+ struct wake_q_head *wake_q)
+{
+ struct msg_receiver *msr, *t;
+
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
+ wake_q_add(wake_q, msr->r_tsk);
+ WRITE_ONCE(msr->r_msg, ERR_PTR(res));
+ }
+}
+
+/*
+ * freeque() wakes up waiters on the sender and receiver waiting queue,
+ * removes the message queue from message queue ID IDR, and cleans up all the
+ * messages associated with this queue.
+ *
+ * msg_ids.rwsem (writer) and the spinlock for this message queue are held
+ * before freeque() is called. msg_ids.rwsem remains locked on exit.
+ */
+static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
+{
+ struct msg_msg *msg, *t;
+ struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
+ DEFINE_WAKE_Q(wake_q);
+
+ expunge_all(msq, -EIDRM, &wake_q);
+ ss_wakeup(msq, &wake_q, true);
+ msg_rmid(ns, msq);
+ ipc_unlock_object(&msq->q_perm);
+ wake_up_q(&wake_q);
+ rcu_read_unlock();
+
+ list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
+ atomic_dec(&ns->msg_hdrs);
+ free_msg(msg);
+ }
+ atomic_sub(msq->q_cbytes, &ns->msg_bytes);
+ ipc_update_pid(&msq->q_lspid, NULL);
+ ipc_update_pid(&msq->q_lrpid, NULL);
+ ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
+}
+
+long ksys_msgget(key_t key, int msgflg)
+{
+ struct ipc_namespace *ns;
+ static const struct ipc_ops msg_ops = {
+ .getnew = newque,
+ .associate = security_msg_queue_associate,
+ };
+ struct ipc_params msg_params;
+
+ ns = current->nsproxy->ipc_ns;
+
+ msg_params.key = key;
+ msg_params.flg = msgflg;
+
+ return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
+}
+
+SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
+{
+ return ksys_msgget(key, msgflg);
+}
+
+static inline unsigned long
+copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
+{
+ switch (version) {
+ case IPC_64:
+ return copy_to_user(buf, in, sizeof(*in));
+ case IPC_OLD:
+ {
+ struct msqid_ds out;
+
+ memset(&out, 0, sizeof(out));
+
+ ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
+
+ out.msg_stime = in->msg_stime;
+ out.msg_rtime = in->msg_rtime;
+ out.msg_ctime = in->msg_ctime;
+
+ if (in->msg_cbytes > USHRT_MAX)
+ out.msg_cbytes = USHRT_MAX;
+ else
+ out.msg_cbytes = in->msg_cbytes;
+ out.msg_lcbytes = in->msg_cbytes;
+
+ if (in->msg_qnum > USHRT_MAX)
+ out.msg_qnum = USHRT_MAX;
+ else
+ out.msg_qnum = in->msg_qnum;
+
+ if (in->msg_qbytes > USHRT_MAX)
+ out.msg_qbytes = USHRT_MAX;
+ else
+ out.msg_qbytes = in->msg_qbytes;
+ out.msg_lqbytes = in->msg_qbytes;
+
+ out.msg_lspid = in->msg_lspid;
+ out.msg_lrpid = in->msg_lrpid;
+
+ return copy_to_user(buf, &out, sizeof(out));
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static inline unsigned long
+copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
+{
+ switch (version) {
+ case IPC_64:
+ if (copy_from_user(out, buf, sizeof(*out)))
+ return -EFAULT;
+ return 0;
+ case IPC_OLD:
+ {
+ struct msqid_ds tbuf_old;
+
+ if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+ return -EFAULT;
+
+ out->msg_perm.uid = tbuf_old.msg_perm.uid;
+ out->msg_perm.gid = tbuf_old.msg_perm.gid;
+ out->msg_perm.mode = tbuf_old.msg_perm.mode;
+
+ if (tbuf_old.msg_qbytes == 0)
+ out->msg_qbytes = tbuf_old.msg_lqbytes;
+ else
+ out->msg_qbytes = tbuf_old.msg_qbytes;
+
+ return 0;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * This function handles some msgctl commands which require the rwsem
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
+ */
+static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
+ struct msqid64_ds *msqid64)
+{
+ struct kern_ipc_perm *ipcp;
+ struct msg_queue *msq;
+ int err;
+
+ down_write(&msg_ids(ns).rwsem);
+ rcu_read_lock();
+
+ ipcp = ipcctl_obtain_check(ns, &msg_ids(ns), msqid, cmd,
+ &msqid64->msg_perm, msqid64->msg_qbytes);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto out_unlock1;
+ }
+
+ msq = container_of(ipcp, struct msg_queue, q_perm);
+
+ err = security_msg_queue_msgctl(&msq->q_perm, cmd);
+ if (err)
+ goto out_unlock1;
+
+ switch (cmd) {
+ case IPC_RMID:
+ ipc_lock_object(&msq->q_perm);
+ /* freeque unlocks the ipc object and rcu */
+ freeque(ns, ipcp);
+ goto out_up;
+ case IPC_SET:
+ {
+ DEFINE_WAKE_Q(wake_q);
+
+ if (msqid64->msg_qbytes > ns->msg_ctlmnb &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EPERM;
+ goto out_unlock1;
+ }
+
+ ipc_lock_object(&msq->q_perm);
+ err = ipc_update_perm(&msqid64->msg_perm, ipcp);
+ if (err)
+ goto out_unlock0;
+
+ msq->q_qbytes = msqid64->msg_qbytes;
+
+ msq->q_ctime = ktime_get_real_seconds();
+ /*
+ * Sleeping receivers might be excluded by
+ * stricter permissions.
+ */
+ expunge_all(msq, -EAGAIN, &wake_q);
+ /*
+ * Sleeping senders might be able to send
+ * due to a larger queue size.
+ */
+ ss_wakeup(msq, &wake_q, false);
+ ipc_unlock_object(&msq->q_perm);
+ wake_up_q(&wake_q);
+
+ goto out_unlock1;
+ }
+ default:
+ err = -EINVAL;
+ goto out_unlock1;
+ }
+
+out_unlock0:
+ ipc_unlock_object(&msq->q_perm);
+out_unlock1:
+ rcu_read_unlock();
+out_up:
+ up_write(&msg_ids(ns).rwsem);
+ return err;
+}
+
+static int msgctl_info(struct ipc_namespace *ns, int msqid,
+ int cmd, struct msginfo *msginfo)
+{
+ int err;
+ int max_idx;
+
+ /*
+ * We must not return kernel stack data.
+ * due to padding, it's not enough
+ * to set all member fields.
+ */
+ err = security_msg_queue_msgctl(NULL, cmd);
+ if (err)
+ return err;
+
+ memset(msginfo, 0, sizeof(*msginfo));
+ msginfo->msgmni = ns->msg_ctlmni;
+ msginfo->msgmax = ns->msg_ctlmax;
+ msginfo->msgmnb = ns->msg_ctlmnb;
+ msginfo->msgssz = MSGSSZ;
+ msginfo->msgseg = MSGSEG;
+ down_read(&msg_ids(ns).rwsem);
+ if (cmd == MSG_INFO) {
+ msginfo->msgpool = msg_ids(ns).in_use;
+ msginfo->msgmap = atomic_read(&ns->msg_hdrs);
+ msginfo->msgtql = atomic_read(&ns->msg_bytes);
+ } else {
+ msginfo->msgmap = MSGMAP;
+ msginfo->msgpool = MSGPOOL;
+ msginfo->msgtql = MSGTQL;
+ }
+ max_idx = ipc_get_maxidx(&msg_ids(ns));
+ up_read(&msg_ids(ns).rwsem);
+ return (max_idx < 0) ? 0 : max_idx;
+}
+
+static int msgctl_stat(struct ipc_namespace *ns, int msqid,
+ int cmd, struct msqid64_ds *p)
+{
+ struct msg_queue *msq;
+ int err;
+
+ memset(p, 0, sizeof(*p));
+
+ rcu_read_lock();
+ if (cmd == MSG_STAT || cmd == MSG_STAT_ANY) {
+ msq = msq_obtain_object(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
+ goto out_unlock;
+ }
+ } else { /* IPC_STAT */
+ msq = msq_obtain_object_check(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
+ goto out_unlock;
+ }
+ }
+
+ /* see comment for SHM_STAT_ANY */
+ if (cmd == MSG_STAT_ANY)
+ audit_ipc_obj(&msq->q_perm);
+ else {
+ err = -EACCES;
+ if (ipcperms(ns, &msq->q_perm, S_IRUGO))
+ goto out_unlock;
+ }
+
+ err = security_msg_queue_msgctl(&msq->q_perm, cmd);
+ if (err)
+ goto out_unlock;
+
+ ipc_lock_object(&msq->q_perm);
+
+ if (!ipc_valid_object(&msq->q_perm)) {
+ ipc_unlock_object(&msq->q_perm);
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm);
+ p->msg_stime = msq->q_stime;
+ p->msg_rtime = msq->q_rtime;
+ p->msg_ctime = msq->q_ctime;
+#ifndef CONFIG_64BIT
+ p->msg_stime_high = msq->q_stime >> 32;
+ p->msg_rtime_high = msq->q_rtime >> 32;
+ p->msg_ctime_high = msq->q_ctime >> 32;
+#endif
+ p->msg_cbytes = msq->q_cbytes;
+ p->msg_qnum = msq->q_qnum;
+ p->msg_qbytes = msq->q_qbytes;
+ p->msg_lspid = pid_vnr(msq->q_lspid);
+ p->msg_lrpid = pid_vnr(msq->q_lrpid);
+
+ if (cmd == IPC_STAT) {
+ /*
+ * As defined in SUS:
+ * Return 0 on success
+ */
+ err = 0;
+ } else {
+ /*
+ * MSG_STAT and MSG_STAT_ANY (both Linux specific)
+ * Return the full id, including the sequence number
+ */
+ err = msq->q_perm.id;
+ }
+
+ ipc_unlock_object(&msq->q_perm);
+out_unlock:
+ rcu_read_unlock();
+ return err;
+}
+
+long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
+{
+ int version;
+ struct ipc_namespace *ns;
+ struct msqid64_ds msqid64;
+ int err;
+
+ if (msqid < 0 || cmd < 0)
+ return -EINVAL;
+
+ version = ipc_parse_version(&cmd);
+ ns = current->nsproxy->ipc_ns;
+
+ switch (cmd) {
+ case IPC_INFO:
+ case MSG_INFO: {
+ struct msginfo msginfo;
+ err = msgctl_info(ns, msqid, cmd, &msginfo);
+ if (err < 0)
+ return err;
+ if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
+ err = -EFAULT;
+ return err;
+ }
+ case MSG_STAT: /* msqid is an index rather than a msg queue id */
+ case MSG_STAT_ANY:
+ case IPC_STAT:
+ err = msgctl_stat(ns, msqid, cmd, &msqid64);
+ if (err < 0)
+ return err;
+ if (copy_msqid_to_user(buf, &msqid64, version))
+ err = -EFAULT;
+ return err;
+ case IPC_SET:
+ if (copy_msqid_from_user(&msqid64, buf, version))
+ return -EFAULT;
+ /* fallthru */
+ case IPC_RMID:
+ return msgctl_down(ns, msqid, cmd, &msqid64);
+ default:
+ return -EINVAL;
+ }
+}
+
+SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
+{
+ return ksys_msgctl(msqid, cmd, buf);
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_msqid_ds {
+ struct compat_ipc_perm msg_perm;
+ compat_uptr_t msg_first;
+ compat_uptr_t msg_last;
+ compat_time_t msg_stime;
+ compat_time_t msg_rtime;
+ compat_time_t msg_ctime;
+ compat_ulong_t msg_lcbytes;
+ compat_ulong_t msg_lqbytes;
+ unsigned short msg_cbytes;
+ unsigned short msg_qnum;
+ unsigned short msg_qbytes;
+ compat_ipc_pid_t msg_lspid;
+ compat_ipc_pid_t msg_lrpid;
+};
+
+static int copy_compat_msqid_from_user(struct msqid64_ds *out, void __user *buf,
+ int version)
+{
+ memset(out, 0, sizeof(*out));
+ if (version == IPC_64) {
+ struct compat_msqid64_ds __user *p = buf;
+ if (get_compat_ipc64_perm(&out->msg_perm, &p->msg_perm))
+ return -EFAULT;
+ if (get_user(out->msg_qbytes, &p->msg_qbytes))
+ return -EFAULT;
+ } else {
+ struct compat_msqid_ds __user *p = buf;
+ if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm))
+ return -EFAULT;
+ if (get_user(out->msg_qbytes, &p->msg_qbytes))
+ return -EFAULT;
+ }
+ return 0;
+}
+
+static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in,
+ int version)
+{
+ if (version == IPC_64) {
+ struct compat_msqid64_ds v;
+ memset(&v, 0, sizeof(v));
+ to_compat_ipc64_perm(&v.msg_perm, &in->msg_perm);
+ v.msg_stime = lower_32_bits(in->msg_stime);
+ v.msg_stime_high = upper_32_bits(in->msg_stime);
+ v.msg_rtime = lower_32_bits(in->msg_rtime);
+ v.msg_rtime_high = upper_32_bits(in->msg_rtime);
+ v.msg_ctime = lower_32_bits(in->msg_ctime);
+ v.msg_ctime_high = upper_32_bits(in->msg_ctime);
+ v.msg_cbytes = in->msg_cbytes;
+ v.msg_qnum = in->msg_qnum;
+ v.msg_qbytes = in->msg_qbytes;
+ v.msg_lspid = in->msg_lspid;
+ v.msg_lrpid = in->msg_lrpid;
+ return copy_to_user(buf, &v, sizeof(v));
+ } else {
+ struct compat_msqid_ds v;
+ memset(&v, 0, sizeof(v));
+ to_compat_ipc_perm(&v.msg_perm, &in->msg_perm);
+ v.msg_stime = in->msg_stime;
+ v.msg_rtime = in->msg_rtime;
+ v.msg_ctime = in->msg_ctime;
+ v.msg_cbytes = in->msg_cbytes;
+ v.msg_qnum = in->msg_qnum;
+ v.msg_qbytes = in->msg_qbytes;
+ v.msg_lspid = in->msg_lspid;
+ v.msg_lrpid = in->msg_lrpid;
+ return copy_to_user(buf, &v, sizeof(v));
+ }
+}
+
+long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr)
+{
+ struct ipc_namespace *ns;
+ int err;
+ struct msqid64_ds msqid64;
+ int version = compat_ipc_parse_version(&cmd);
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (msqid < 0 || cmd < 0)
+ return -EINVAL;
+
+ switch (cmd & (~IPC_64)) {
+ case IPC_INFO:
+ case MSG_INFO: {
+ struct msginfo msginfo;
+ err = msgctl_info(ns, msqid, cmd, &msginfo);
+ if (err < 0)
+ return err;
+ if (copy_to_user(uptr, &msginfo, sizeof(struct msginfo)))
+ err = -EFAULT;
+ return err;
+ }
+ case IPC_STAT:
+ case MSG_STAT:
+ case MSG_STAT_ANY:
+ err = msgctl_stat(ns, msqid, cmd, &msqid64);
+ if (err < 0)
+ return err;
+ if (copy_compat_msqid_to_user(uptr, &msqid64, version))
+ err = -EFAULT;
+ return err;
+ case IPC_SET:
+ if (copy_compat_msqid_from_user(&msqid64, uptr, version))
+ return -EFAULT;
+ /* fallthru */
+ case IPC_RMID:
+ return msgctl_down(ns, msqid, cmd, &msqid64);
+ default:
+ return -EINVAL;
+ }
+}
+
+COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
+{
+ return compat_ksys_msgctl(msqid, cmd, uptr);
+}
+#endif
+
+static int testmsg(struct msg_msg *msg, long type, int mode)
+{
+ switch (mode) {
+ case SEARCH_ANY:
+ case SEARCH_NUMBER:
+ return 1;
+ case SEARCH_LESSEQUAL:
+ if (msg->m_type <= type)
+ return 1;
+ break;
+ case SEARCH_EQUAL:
+ if (msg->m_type == type)
+ return 1;
+ break;
+ case SEARCH_NOTEQUAL:
+ if (msg->m_type != type)
+ return 1;
+ break;
+ }
+ return 0;
+}
+
+static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
+ struct wake_q_head *wake_q)
+{
+ struct msg_receiver *msr, *t;
+
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
+ if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
+ !security_msg_queue_msgrcv(&msq->q_perm, msg, msr->r_tsk,
+ msr->r_msgtype, msr->r_mode)) {
+
+ list_del(&msr->r_list);
+ if (msr->r_maxsize < msg->m_ts) {
+ wake_q_add(wake_q, msr->r_tsk);
+ WRITE_ONCE(msr->r_msg, ERR_PTR(-E2BIG));
+ } else {
+ ipc_update_pid(&msq->q_lrpid, task_pid(msr->r_tsk));
+ msq->q_rtime = ktime_get_real_seconds();
+
+ wake_q_add(wake_q, msr->r_tsk);
+ WRITE_ONCE(msr->r_msg, msg);
+ return 1;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static long do_msgsnd(int msqid, long mtype, void __user *mtext,
+ size_t msgsz, int msgflg)
+{
+ struct msg_queue *msq;
+ struct msg_msg *msg;
+ int err;
+ struct ipc_namespace *ns;
+ DEFINE_WAKE_Q(wake_q);
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
+ return -EINVAL;
+ if (mtype < 1)
+ return -EINVAL;
+
+ msg = load_msg(mtext, msgsz);
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+
+ msg->m_type = mtype;
+ msg->m_ts = msgsz;
+
+ rcu_read_lock();
+ msq = msq_obtain_object_check(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
+ goto out_unlock1;
+ }
+
+ ipc_lock_object(&msq->q_perm);
+
+ for (;;) {
+ struct msg_sender s;
+
+ err = -EACCES;
+ if (ipcperms(ns, &msq->q_perm, S_IWUGO))
+ goto out_unlock0;
+
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
+
+ err = security_msg_queue_msgsnd(&msq->q_perm, msg, msgflg);
+ if (err)
+ goto out_unlock0;
+
+ if (msg_fits_inqueue(msq, msgsz))
+ break;
+
+ /* queue full, wait: */
+ if (msgflg & IPC_NOWAIT) {
+ err = -EAGAIN;
+ goto out_unlock0;
+ }
+
+ /* enqueue the sender and prepare to block */
+ ss_add(msq, &s, msgsz);
+
+ if (!ipc_rcu_getref(&msq->q_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
+
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
+ schedule();
+
+ rcu_read_lock();
+ ipc_lock_object(&msq->q_perm);
+
+ ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
+ ss_del(&s);
+
+ if (signal_pending(current)) {
+ err = -ERESTARTNOHAND;
+ goto out_unlock0;
+ }
+
+ }
+
+ ipc_update_pid(&msq->q_lspid, task_tgid(current));
+ msq->q_stime = ktime_get_real_seconds();
+
+ if (!pipelined_send(msq, msg, &wake_q)) {
+ /* no one is waiting for this message, enqueue it */
+ list_add_tail(&msg->m_list, &msq->q_messages);
+ msq->q_cbytes += msgsz;
+ msq->q_qnum++;
+ atomic_add(msgsz, &ns->msg_bytes);
+ atomic_inc(&ns->msg_hdrs);
+ }
+
+ err = 0;
+ msg = NULL;
+
+out_unlock0:
+ ipc_unlock_object(&msq->q_perm);
+ wake_up_q(&wake_q);
+out_unlock1:
+ rcu_read_unlock();
+ if (msg != NULL)
+ free_msg(msg);
+ return err;
+}
+
+long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+ int msgflg)
+{
+ long mtype;
+
+ if (get_user(mtype, &msgp->mtype))
+ return -EFAULT;
+ return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
+}
+
+SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
+ int, msgflg)
+{
+ return ksys_msgsnd(msqid, msgp, msgsz, msgflg);
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_msgbuf {
+ compat_long_t mtype;
+ char mtext[1];
+};
+
+long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
+ compat_ssize_t msgsz, int msgflg)
+{
+ struct compat_msgbuf __user *up = compat_ptr(msgp);
+ compat_long_t mtype;
+
+ if (get_user(mtype, &up->mtype))
+ return -EFAULT;
+ return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
+}
+
+COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
+ compat_ssize_t, msgsz, int, msgflg)
+{
+ return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg);
+}
+#endif
+
+static inline int convert_mode(long *msgtyp, int msgflg)
+{
+ if (msgflg & MSG_COPY)
+ return SEARCH_NUMBER;
+ /*
+ * find message of correct type.
+ * msgtyp = 0 => get first.
+ * msgtyp > 0 => get first message of matching type.
+ * msgtyp < 0 => get message with least type must be < abs(msgtype).
+ */
+ if (*msgtyp == 0)
+ return SEARCH_ANY;
+ if (*msgtyp < 0) {
+ if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */
+ *msgtyp = LONG_MAX;
+ else
+ *msgtyp = -*msgtyp;
+ return SEARCH_LESSEQUAL;
+ }
+ if (msgflg & MSG_EXCEPT)
+ return SEARCH_NOTEQUAL;
+ return SEARCH_EQUAL;
+}
+
+static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+ struct msgbuf __user *msgp = dest;
+ size_t msgsz;
+
+ if (put_user(msg->m_type, &msgp->mtype))
+ return -EFAULT;
+
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
+}
+
+#ifdef CONFIG_CHECKPOINT_RESTORE
+/*
+ * This function creates new kernel message structure, large enough to store
+ * bufsz message bytes.
+ */
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
+{
+ struct msg_msg *copy;
+
+ /*
+ * Create dummy message to copy real message to.
+ */
+ copy = load_msg(buf, bufsz);
+ if (!IS_ERR(copy))
+ copy->m_ts = bufsz;
+ return copy;
+}
+
+static inline void free_copy(struct msg_msg *copy)
+{
+ if (copy)
+ free_msg(copy);
+}
+#else
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline void free_copy(struct msg_msg *copy)
+{
+}
+#endif
+
+static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
+{
+ struct msg_msg *msg, *found = NULL;
+ long count = 0;
+
+ list_for_each_entry(msg, &msq->q_messages, m_list) {
+ if (testmsg(msg, *msgtyp, mode) &&
+ !security_msg_queue_msgrcv(&msq->q_perm, msg, current,
+ *msgtyp, mode)) {
+ if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
+ *msgtyp = msg->m_type - 1;
+ found = msg;
+ } else if (mode == SEARCH_NUMBER) {
+ if (*msgtyp == count)
+ return msg;
+ } else
+ return msg;
+ count++;
+ }
+ }
+
+ return found ?: ERR_PTR(-EAGAIN);
+}
+
+static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
+ long (*msg_handler)(void __user *, struct msg_msg *, size_t))
+{
+ int mode;
+ struct msg_queue *msq;
+ struct ipc_namespace *ns;
+ struct msg_msg *msg, *copy = NULL;
+ DEFINE_WAKE_Q(wake_q);
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (msqid < 0 || (long) bufsz < 0)
+ return -EINVAL;
+
+ if (msgflg & MSG_COPY) {
+ if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
+ return -EINVAL;
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
+ if (IS_ERR(copy))
+ return PTR_ERR(copy);
+ }
+ mode = convert_mode(&msgtyp, msgflg);
+
+ rcu_read_lock();
+ msq = msq_obtain_object_check(ns, msqid);
+ if (IS_ERR(msq)) {
+ rcu_read_unlock();
+ free_copy(copy);
+ return PTR_ERR(msq);
+ }
+
+ for (;;) {
+ struct msg_receiver msr_d;
+
+ msg = ERR_PTR(-EACCES);
+ if (ipcperms(ns, &msq->q_perm, S_IRUGO))
+ goto out_unlock1;
+
+ ipc_lock_object(&msq->q_perm);
+
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
+ msg = ERR_PTR(-EIDRM);
+ goto out_unlock0;
+ }
+
+ msg = find_msg(msq, &msgtyp, mode);
+ if (!IS_ERR(msg)) {
+ /*
+ * Found a suitable message.
+ * Unlink it from the queue.
+ */
+ if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
+ msg = ERR_PTR(-E2BIG);
+ goto out_unlock0;
+ }
+ /*
+ * If we are copying, then do not unlink message and do
+ * not update queue parameters.
+ */
+ if (msgflg & MSG_COPY) {
+ msg = copy_msg(msg, copy);
+ goto out_unlock0;
+ }
+
+ list_del(&msg->m_list);
+ msq->q_qnum--;
+ msq->q_rtime = ktime_get_real_seconds();
+ ipc_update_pid(&msq->q_lrpid, task_tgid(current));
+ msq->q_cbytes -= msg->m_ts;
+ atomic_sub(msg->m_ts, &ns->msg_bytes);
+ atomic_dec(&ns->msg_hdrs);
+ ss_wakeup(msq, &wake_q, false);
+
+ goto out_unlock0;
+ }
+
+ /* No message waiting. Wait for a message */
+ if (msgflg & IPC_NOWAIT) {
+ msg = ERR_PTR(-ENOMSG);
+ goto out_unlock0;
+ }
+
+ list_add_tail(&msr_d.r_list, &msq->q_receivers);
+ msr_d.r_tsk = current;
+ msr_d.r_msgtype = msgtyp;
+ msr_d.r_mode = mode;
+ if (msgflg & MSG_NOERROR)
+ msr_d.r_maxsize = INT_MAX;
+ else
+ msr_d.r_maxsize = bufsz;
+ msr_d.r_msg = ERR_PTR(-EAGAIN);
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
+ schedule();
+
+ /*
+ * Lockless receive, part 1:
+ * We don't hold a reference to the queue and getting a
+ * reference would defeat the idea of a lockless operation,
+ * thus the code relies on rcu to guarantee the existence of
+ * msq:
+ * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
+ * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
+ */
+ rcu_read_lock();
+
+ /*
+ * Lockless receive, part 2:
+ * The work in pipelined_send() and expunge_all():
+ * - Set pointer to message
+ * - Queue the receiver task for later wakeup
+ * - Wake up the process after the lock is dropped.
+ *
+ * Should the process wake up before this wakeup (due to a
+ * signal) it will either see the message and continue ...
+ */
+ msg = READ_ONCE(msr_d.r_msg);
+ if (msg != ERR_PTR(-EAGAIN))
+ goto out_unlock1;
+
+ /*
+ * ... or see -EAGAIN, acquire the lock to check the message
+ * again.
+ */
+ ipc_lock_object(&msq->q_perm);
+
+ msg = msr_d.r_msg;
+ if (msg != ERR_PTR(-EAGAIN))
+ goto out_unlock0;
+
+ list_del(&msr_d.r_list);
+ if (signal_pending(current)) {
+ msg = ERR_PTR(-ERESTARTNOHAND);
+ goto out_unlock0;
+ }
+
+ ipc_unlock_object(&msq->q_perm);
+ }
+
+out_unlock0:
+ ipc_unlock_object(&msq->q_perm);
+ wake_up_q(&wake_q);
+out_unlock1:
+ rcu_read_unlock();
+ if (IS_ERR(msg)) {
+ free_copy(copy);
+ return PTR_ERR(msg);
+ }
+
+ bufsz = msg_handler(buf, msg, bufsz);
+ free_msg(msg);
+
+ return bufsz;
+}
+
+long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+ long msgtyp, int msgflg)
+{
+ return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
+}
+
+SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
+ long, msgtyp, int, msgflg)
+{
+ return ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
+}
+
+#ifdef CONFIG_COMPAT
+static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+ struct compat_msgbuf __user *msgp = dest;
+ size_t msgsz;
+
+ if (put_user(msg->m_type, &msgp->mtype))
+ return -EFAULT;
+
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
+}
+
+long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
+ compat_long_t msgtyp, int msgflg)
+{
+ return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
+ msgflg, compat_do_msg_fill);
+}
+
+COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
+ compat_ssize_t, msgsz, compat_long_t, msgtyp,
+ int, msgflg)
+{
+ return compat_ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
+}
+#endif
+
+void msg_init_ns(struct ipc_namespace *ns)
+{
+ ns->msg_ctlmax = MSGMAX;
+ ns->msg_ctlmnb = MSGMNB;
+ ns->msg_ctlmni = MSGMNI;
+
+ atomic_set(&ns->msg_bytes, 0);
+ atomic_set(&ns->msg_hdrs, 0);
+ ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
+}
+
+#ifdef CONFIG_IPC_NS
+void msg_exit_ns(struct ipc_namespace *ns)
+{
+ free_ipcs(ns, &msg_ids(ns), freeque);
+ idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
+ rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht);
+}
+#endif
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
+{
+ struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
+ struct user_namespace *user_ns = seq_user_ns(s);
+ struct kern_ipc_perm *ipcp = it;
+ struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
+
+ seq_printf(s,
+ "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10llu %10llu %10llu\n",
+ msq->q_perm.key,
+ msq->q_perm.id,
+ msq->q_perm.mode,
+ msq->q_cbytes,
+ msq->q_qnum,
+ pid_nr_ns(msq->q_lspid, pid_ns),
+ pid_nr_ns(msq->q_lrpid, pid_ns),
+ from_kuid_munged(user_ns, msq->q_perm.uid),
+ from_kgid_munged(user_ns, msq->q_perm.gid),
+ from_kuid_munged(user_ns, msq->q_perm.cuid),
+ from_kgid_munged(user_ns, msq->q_perm.cgid),
+ msq->q_stime,
+ msq->q_rtime,
+ msq->q_ctime);
+
+ return 0;
+}
+#endif
+
+void __init msg_init(void)
+{
+ msg_init_ns(&init_ipc_ns);
+
+ ipc_init_proc_interface("sysvipc/msg",
+ " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n",
+ IPC_MSG_IDS, sysvipc_msg_proc_show);
+}
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
new file mode 100644
index 0000000..8459802
--- /dev/null
+++ b/ipc/msgutil.c
@@ -0,0 +1,182 @@
+/*
+ * linux/ipc/msgutil.c
+ * Copyright (C) 1999, 2004 Manfred Spraul
+ *
+ * This file is released under GNU General Public Licence version 2 or
+ * (at your option) any later version.
+ *
+ * See the file COPYING for more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/ipc.h>
+#include <linux/msg.h>
+#include <linux/ipc_namespace.h>
+#include <linux/utsname.h>
+#include <linux/proc_ns.h>
+#include <linux/uaccess.h>
+
+#include "util.h"
+
+DEFINE_SPINLOCK(mq_lock);
+
+/*
+ * The next 2 defines are here bc this is the only file
+ * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
+ * and not CONFIG_IPC_NS.
+ */
+struct ipc_namespace init_ipc_ns = {
+ .count = REFCOUNT_INIT(1),
+ .user_ns = &init_user_ns,
+ .ns.inum = PROC_IPC_INIT_INO,
+#ifdef CONFIG_IPC_NS
+ .ns.ops = &ipcns_operations,
+#endif
+};
+
+struct msg_msgseg {
+ struct msg_msgseg *next;
+ /* the next part of the message follows immediately */
+};
+
+#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
+#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
+
+
+static struct msg_msg *alloc_msg(size_t len)
+{
+ struct msg_msg *msg;
+ struct msg_msgseg **pseg;
+ size_t alen;
+
+ alen = min(len, DATALEN_MSG);
+ msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL_ACCOUNT);
+ if (msg == NULL)
+ return NULL;
+
+ msg->next = NULL;
+ msg->security = NULL;
+
+ len -= alen;
+ pseg = &msg->next;
+ while (len > 0) {
+ struct msg_msgseg *seg;
+ alen = min(len, DATALEN_SEG);
+ seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT);
+ if (seg == NULL)
+ goto out_err;
+ *pseg = seg;
+ seg->next = NULL;
+ pseg = &seg->next;
+ len -= alen;
+ }
+
+ return msg;
+
+out_err:
+ free_msg(msg);
+ return NULL;
+}
+
+struct msg_msg *load_msg(const void __user *src, size_t len)
+{
+ struct msg_msg *msg;
+ struct msg_msgseg *seg;
+ int err = -EFAULT;
+ size_t alen;
+
+ msg = alloc_msg(len);
+ if (msg == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ alen = min(len, DATALEN_MSG);
+ if (copy_from_user(msg + 1, src, alen))
+ goto out_err;
+
+ for (seg = msg->next; seg != NULL; seg = seg->next) {
+ len -= alen;
+ src = (char __user *)src + alen;
+ alen = min(len, DATALEN_SEG);
+ if (copy_from_user(seg + 1, src, alen))
+ goto out_err;
+ }
+
+ err = security_msg_msg_alloc(msg);
+ if (err)
+ goto out_err;
+
+ return msg;
+
+out_err:
+ free_msg(msg);
+ return ERR_PTR(err);
+}
+#ifdef CONFIG_CHECKPOINT_RESTORE
+struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
+{
+ struct msg_msgseg *dst_pseg, *src_pseg;
+ size_t len = src->m_ts;
+ size_t alen;
+
+ if (src->m_ts > dst->m_ts)
+ return ERR_PTR(-EINVAL);
+
+ alen = min(len, DATALEN_MSG);
+ memcpy(dst + 1, src + 1, alen);
+
+ for (dst_pseg = dst->next, src_pseg = src->next;
+ src_pseg != NULL;
+ dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
+
+ len -= alen;
+ alen = min(len, DATALEN_SEG);
+ memcpy(dst_pseg + 1, src_pseg + 1, alen);
+ }
+
+ dst->m_type = src->m_type;
+ dst->m_ts = src->m_ts;
+
+ return dst;
+}
+#else
+struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
+{
+ return ERR_PTR(-ENOSYS);
+}
+#endif
+int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
+{
+ size_t alen;
+ struct msg_msgseg *seg;
+
+ alen = min(len, DATALEN_MSG);
+ if (copy_to_user(dest, msg + 1, alen))
+ return -1;
+
+ for (seg = msg->next; seg != NULL; seg = seg->next) {
+ len -= alen;
+ dest = (char __user *)dest + alen;
+ alen = min(len, DATALEN_SEG);
+ if (copy_to_user(dest, seg + 1, alen))
+ return -1;
+ }
+ return 0;
+}
+
+void free_msg(struct msg_msg *msg)
+{
+ struct msg_msgseg *seg;
+
+ security_msg_msg_free(msg);
+
+ seg = msg->next;
+ kfree(msg);
+ while (seg != NULL) {
+ struct msg_msgseg *tmp = seg->next;
+ kfree(seg);
+ seg = tmp;
+ }
+}
diff --git a/ipc/namespace.c b/ipc/namespace.c
new file mode 100644
index 0000000..2160779
--- /dev/null
+++ b/ipc/namespace.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/ipc/namespace.c
+ * Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc.
+ */
+
+#include <linux/ipc.h>
+#include <linux/msg.h>
+#include <linux/ipc_namespace.h>
+#include <linux/rcupdate.h>
+#include <linux/nsproxy.h>
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/user_namespace.h>
+#include <linux/proc_ns.h>
+#include <linux/sched/task.h>
+
+#include "util.h"
+
+static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns)
+{
+ return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES);
+}
+
+static void dec_ipc_namespaces(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_IPC_NAMESPACES);
+}
+
+static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
+ struct ipc_namespace *old_ns)
+{
+ struct ipc_namespace *ns;
+ struct ucounts *ucounts;
+ int err;
+
+ err = -ENOSPC;
+ ucounts = inc_ipc_namespaces(user_ns);
+ if (!ucounts)
+ goto fail;
+
+ err = -ENOMEM;
+ ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
+ if (ns == NULL)
+ goto fail_dec;
+
+ err = ns_alloc_inum(&ns->ns);
+ if (err)
+ goto fail_free;
+ ns->ns.ops = &ipcns_operations;
+
+ refcount_set(&ns->count, 1);
+ ns->user_ns = get_user_ns(user_ns);
+ ns->ucounts = ucounts;
+
+ err = mq_init_ns(ns);
+ if (err)
+ goto fail_put;
+
+ sem_init_ns(ns);
+ msg_init_ns(ns);
+ shm_init_ns(ns);
+
+ return ns;
+
+fail_put:
+ put_user_ns(ns->user_ns);
+ ns_free_inum(&ns->ns);
+fail_free:
+ kfree(ns);
+fail_dec:
+ dec_ipc_namespaces(ucounts);
+fail:
+ return ERR_PTR(err);
+}
+
+struct ipc_namespace *copy_ipcs(unsigned long flags,
+ struct user_namespace *user_ns, struct ipc_namespace *ns)
+{
+ if (!(flags & CLONE_NEWIPC))
+ return get_ipc_ns(ns);
+ return create_ipc_ns(user_ns, ns);
+}
+
+/*
+ * free_ipcs - free all ipcs of one type
+ * @ns: the namespace to remove the ipcs from
+ * @ids: the table of ipcs to free
+ * @free: the function called to free each individual ipc
+ *
+ * Called for each kind of ipc when an ipc_namespace exits.
+ */
+void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
+ void (*free)(struct ipc_namespace *, struct kern_ipc_perm *))
+{
+ struct kern_ipc_perm *perm;
+ int next_id;
+ int total, in_use;
+
+ down_write(&ids->rwsem);
+
+ in_use = ids->in_use;
+
+ for (total = 0, next_id = 0; total < in_use; next_id++) {
+ perm = idr_find(&ids->ipcs_idr, next_id);
+ if (perm == NULL)
+ continue;
+ rcu_read_lock();
+ ipc_lock_object(perm);
+ free(ns, perm);
+ total++;
+ }
+ up_write(&ids->rwsem);
+}
+
+static void free_ipc_ns(struct ipc_namespace *ns)
+{
+ sem_exit_ns(ns);
+ msg_exit_ns(ns);
+ shm_exit_ns(ns);
+
+ dec_ipc_namespaces(ns->ucounts);
+ put_user_ns(ns->user_ns);
+ ns_free_inum(&ns->ns);
+ kfree(ns);
+}
+
+/*
+ * put_ipc_ns - drop a reference to an ipc namespace.
+ * @ns: the namespace to put
+ *
+ * If this is the last task in the namespace exiting, and
+ * it is dropping the refcount to 0, then it can race with
+ * a task in another ipc namespace but in a mounts namespace
+ * which has this ipcns's mqueuefs mounted, doing some action
+ * with one of the mqueuefs files. That can raise the refcount.
+ * So dropping the refcount, and raising the refcount when
+ * accessing it through the VFS, are protected with mq_lock.
+ *
+ * (Clearly, a task raising the refcount on its own ipc_ns
+ * needn't take mq_lock since it can't race with the last task
+ * in the ipcns exiting).
+ */
+void put_ipc_ns(struct ipc_namespace *ns)
+{
+ if (refcount_dec_and_lock(&ns->count, &mq_lock)) {
+ mq_clear_sbinfo(ns);
+ spin_unlock(&mq_lock);
+ mq_put_mnt(ns);
+ free_ipc_ns(ns);
+ }
+}
+
+static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns)
+{
+ return container_of(ns, struct ipc_namespace, ns);
+}
+
+static struct ns_common *ipcns_get(struct task_struct *task)
+{
+ struct ipc_namespace *ns = NULL;
+ struct nsproxy *nsproxy;
+
+ task_lock(task);
+ nsproxy = task->nsproxy;
+ if (nsproxy)
+ ns = get_ipc_ns(nsproxy->ipc_ns);
+ task_unlock(task);
+
+ return ns ? &ns->ns : NULL;
+}
+
+static void ipcns_put(struct ns_common *ns)
+{
+ return put_ipc_ns(to_ipc_ns(ns));
+}
+
+static int ipcns_install(struct nsproxy *nsproxy, struct ns_common *new)
+{
+ struct ipc_namespace *ns = to_ipc_ns(new);
+ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
+ !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* Ditch state from the old ipc namespace */
+ exit_sem(current);
+ put_ipc_ns(nsproxy->ipc_ns);
+ nsproxy->ipc_ns = get_ipc_ns(ns);
+ return 0;
+}
+
+static struct user_namespace *ipcns_owner(struct ns_common *ns)
+{
+ return to_ipc_ns(ns)->user_ns;
+}
+
+const struct proc_ns_operations ipcns_operations = {
+ .name = "ipc",
+ .type = CLONE_NEWIPC,
+ .get = ipcns_get,
+ .put = ipcns_put,
+ .install = ipcns_install,
+ .owner = ipcns_owner,
+};
diff --git a/ipc/sem.c b/ipc/sem.c
new file mode 100644
index 0000000..26f8e37
--- /dev/null
+++ b/ipc/sem.c
@@ -0,0 +1,2425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/ipc/sem.c
+ * Copyright (C) 1992 Krishna Balasubramanian
+ * Copyright (C) 1995 Eric Schenk, Bruno Haible
+ *
+ * /proc/sysvipc/sem support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
+ *
+ * SMP-threaded, sysctl's added
+ * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
+ * Enforced range limit on SEM_UNDO
+ * (c) 2001 Red Hat Inc
+ * Lockless wakeup
+ * (c) 2003 Manfred Spraul <manfred@colorfullife.com>
+ * (c) 2016 Davidlohr Bueso <dave@stgolabs.net>
+ * Further wakeup optimizations, documentation
+ * (c) 2010 Manfred Spraul <manfred@colorfullife.com>
+ *
+ * support for audit of ipc object properties and permission changes
+ * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ *
+ * namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ *
+ * Implementation notes: (May 2010)
+ * This file implements System V semaphores.
+ *
+ * User space visible behavior:
+ * - FIFO ordering for semop() operations (just FIFO, not starvation
+ * protection)
+ * - multiple semaphore operations that alter the same semaphore in
+ * one semop() are handled.
+ * - sem_ctime (time of last semctl()) is updated in the IPC_SET, SETVAL and
+ * SETALL calls.
+ * - two Linux specific semctl() commands: SEM_STAT, SEM_INFO.
+ * - undo adjustments at process exit are limited to 0..SEMVMX.
+ * - namespace are supported.
+ * - SEMMSL, SEMMNS, SEMOPM and SEMMNI can be configured at runtine by writing
+ * to /proc/sys/kernel/sem.
+ * - statistics about the usage are reported in /proc/sysvipc/sem.
+ *
+ * Internals:
+ * - scalability:
+ * - all global variables are read-mostly.
+ * - semop() calls and semctl(RMID) are synchronized by RCU.
+ * - most operations do write operations (actually: spin_lock calls) to
+ * the per-semaphore array structure.
+ * Thus: Perfect SMP scaling between independent semaphore arrays.
+ * If multiple semaphores in one array are used, then cache line
+ * trashing on the semaphore array spinlock will limit the scaling.
+ * - semncnt and semzcnt are calculated on demand in count_semcnt()
+ * - the task that performs a successful semop() scans the list of all
+ * sleeping tasks and completes any pending operations that can be fulfilled.
+ * Semaphores are actively given to waiting tasks (necessary for FIFO).
+ * (see update_queue())
+ * - To improve the scalability, the actual wake-up calls are performed after
+ * dropping all locks. (see wake_up_sem_queue_prepare())
+ * - All work is done by the waker, the woken up task does not have to do
+ * anything - not even acquiring a lock or dropping a refcount.
+ * - A woken up task may not even touch the semaphore array anymore, it may
+ * have been destroyed already by a semctl(RMID).
+ * - UNDO values are stored in an array (one per process and per
+ * semaphore array, lazily allocated). For backwards compatibility, multiple
+ * modes for the UNDO variables are supported (per process, per thread)
+ * (see copy_semundo, CLONE_SYSVSEM)
+ * - There are two lists of the pending operations: a per-array list
+ * and per-semaphore list (stored in the array). This allows to achieve FIFO
+ * ordering without always scanning all pending operations.
+ * The worst-case behavior is nevertheless O(N^2) for N wakeups.
+ */
+
+#include <linux/compat.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/time.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <linux/capability.h>
+#include <linux/seq_file.h>
+#include <linux/rwsem.h>
+#include <linux/nsproxy.h>
+#include <linux/ipc_namespace.h>
+#include <linux/sched/wake_q.h>
+#include <linux/nospec.h>
+#include <linux/rhashtable.h>
+
+#include <linux/uaccess.h>
+#include "util.h"
+
+/* One semaphore structure for each semaphore in the system. */
+struct sem {
+ int semval; /* current value */
+ /*
+ * PID of the process that last modified the semaphore. For
+ * Linux, specifically these are:
+ * - semop
+ * - semctl, via SETVAL and SETALL.
+ * - at task exit when performing undo adjustments (see exit_sem).
+ */
+ struct pid *sempid;
+ spinlock_t lock; /* spinlock for fine-grained semtimedop */
+ struct list_head pending_alter; /* pending single-sop operations */
+ /* that alter the semaphore */
+ struct list_head pending_const; /* pending single-sop operations */
+ /* that do not alter the semaphore*/
+ time64_t sem_otime; /* candidate for sem_otime */
+} ____cacheline_aligned_in_smp;
+
+/* One sem_array data structure for each set of semaphores in the system. */
+struct sem_array {
+ struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
+ time64_t sem_ctime; /* create/last semctl() time */
+ struct list_head pending_alter; /* pending operations */
+ /* that alter the array */
+ struct list_head pending_const; /* pending complex operations */
+ /* that do not alter semvals */
+ struct list_head list_id; /* undo requests on this array */
+ int sem_nsems; /* no. of semaphores in array */
+ int complex_count; /* pending complex operations */
+ unsigned int use_global_lock;/* >0: global lock required */
+
+ struct sem sems[];
+} __randomize_layout;
+
+/* One queue for each sleeping process in the system. */
+struct sem_queue {
+ struct list_head list; /* queue of pending operations */
+ struct task_struct *sleeper; /* this process */
+ struct sem_undo *undo; /* undo structure */
+ struct pid *pid; /* process id of requesting process */
+ int status; /* completion status of operation */
+ struct sembuf *sops; /* array of pending operations */
+ struct sembuf *blocking; /* the operation that blocked */
+ int nsops; /* number of operations */
+ bool alter; /* does *sops alter the array? */
+ bool dupsop; /* sops on more than one sem_num */
+};
+
+/* Each task has a list of undo requests. They are executed automatically
+ * when the process exits.
+ */
+struct sem_undo {
+ struct list_head list_proc; /* per-process list: *
+ * all undos from one process
+ * rcu protected */
+ struct rcu_head rcu; /* rcu struct for sem_undo */
+ struct sem_undo_list *ulp; /* back ptr to sem_undo_list */
+ struct list_head list_id; /* per semaphore array list:
+ * all undos for one array */
+ int semid; /* semaphore set identifier */
+ short *semadj; /* array of adjustments */
+ /* one per semaphore */
+};
+
+/* sem_undo_list controls shared access to the list of sem_undo structures
+ * that may be shared among all a CLONE_SYSVSEM task group.
+ */
+struct sem_undo_list {
+ refcount_t refcnt;
+ spinlock_t lock;
+ struct list_head list_proc;
+};
+
+
+#define sem_ids(ns) ((ns)->ids[IPC_SEM_IDS])
+
+static int newary(struct ipc_namespace *, struct ipc_params *);
+static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);
+#ifdef CONFIG_PROC_FS
+static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
+#endif
+
+#define SEMMSL_FAST 256 /* 512 bytes on stack */
+#define SEMOPM_FAST 64 /* ~ 372 bytes on stack */
+
+/*
+ * Switching from the mode suitable for simple ops
+ * to the mode for complex ops is costly. Therefore:
+ * use some hysteresis
+ */
+#define USE_GLOBAL_LOCK_HYSTERESIS 10
+
+/*
+ * Locking:
+ * a) global sem_lock() for read/write
+ * sem_undo.id_next,
+ * sem_array.complex_count,
+ * sem_array.pending{_alter,_const},
+ * sem_array.sem_undo
+ *
+ * b) global or semaphore sem_lock() for read/write:
+ * sem_array.sems[i].pending_{const,alter}:
+ *
+ * c) special:
+ * sem_undo_list.list_proc:
+ * * undo_list->lock for write
+ * * rcu for read
+ * use_global_lock:
+ * * global sem_lock() for write
+ * * either local or global sem_lock() for read.
+ *
+ * Memory ordering:
+ * Most ordering is enforced by using spin_lock() and spin_unlock().
+ * The special case is use_global_lock:
+ * Setting it from non-zero to 0 is a RELEASE, this is ensured by
+ * using smp_store_release().
+ * Testing if it is non-zero is an ACQUIRE, this is ensured by using
+ * smp_load_acquire().
+ * Setting it from 0 to non-zero must be ordered with regards to
+ * this smp_load_acquire(), this is guaranteed because the smp_load_acquire()
+ * is inside a spin_lock() and after a write from 0 to non-zero a
+ * spin_lock()+spin_unlock() is done.
+ */
+
+#define sc_semmsl sem_ctls[0]
+#define sc_semmns sem_ctls[1]
+#define sc_semopm sem_ctls[2]
+#define sc_semmni sem_ctls[3]
+
+void sem_init_ns(struct ipc_namespace *ns)
+{
+ ns->sc_semmsl = SEMMSL;
+ ns->sc_semmns = SEMMNS;
+ ns->sc_semopm = SEMOPM;
+ ns->sc_semmni = SEMMNI;
+ ns->used_sems = 0;
+ ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
+}
+
+#ifdef CONFIG_IPC_NS
+void sem_exit_ns(struct ipc_namespace *ns)
+{
+ free_ipcs(ns, &sem_ids(ns), freeary);
+ idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr);
+ rhashtable_destroy(&ns->ids[IPC_SEM_IDS].key_ht);
+}
+#endif
+
+void __init sem_init(void)
+{
+ sem_init_ns(&init_ipc_ns);
+ ipc_init_proc_interface("sysvipc/sem",
+ " key semid perms nsems uid gid cuid cgid otime ctime\n",
+ IPC_SEM_IDS, sysvipc_sem_proc_show);
+}
+
+/**
+ * unmerge_queues - unmerge queues, if possible.
+ * @sma: semaphore array
+ *
+ * The function unmerges the wait queues if complex_count is 0.
+ * It must be called prior to dropping the global semaphore array lock.
+ */
+static void unmerge_queues(struct sem_array *sma)
+{
+ struct sem_queue *q, *tq;
+
+ /* complex operations still around? */
+ if (sma->complex_count)
+ return;
+ /*
+ * We will switch back to simple mode.
+ * Move all pending operation back into the per-semaphore
+ * queues.
+ */
+ list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
+ struct sem *curr;
+ curr = &sma->sems[q->sops[0].sem_num];
+
+ list_add_tail(&q->list, &curr->pending_alter);
+ }
+ INIT_LIST_HEAD(&sma->pending_alter);
+}
+
+/**
+ * merge_queues - merge single semop queues into global queue
+ * @sma: semaphore array
+ *
+ * This function merges all per-semaphore queues into the global queue.
+ * It is necessary to achieve FIFO ordering for the pending single-sop
+ * operations when a multi-semop operation must sleep.
+ * Only the alter operations must be moved, the const operations can stay.
+ */
+static void merge_queues(struct sem_array *sma)
+{
+ int i;
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *sem = &sma->sems[i];
+
+ list_splice_init(&sem->pending_alter, &sma->pending_alter);
+ }
+}
+
+static void sem_rcu_free(struct rcu_head *head)
+{
+ struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
+ struct sem_array *sma = container_of(p, struct sem_array, sem_perm);
+
+ security_sem_free(&sma->sem_perm);
+ kvfree(sma);
+}
+
+/*
+ * Enter the mode suitable for non-simple operations:
+ * Caller must own sem_perm.lock.
+ */
+static void complexmode_enter(struct sem_array *sma)
+{
+ int i;
+ struct sem *sem;
+
+ if (sma->use_global_lock > 0) {
+ /*
+ * We are already in global lock mode.
+ * Nothing to do, just reset the
+ * counter until we return to simple mode.
+ */
+ sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS;
+ return;
+ }
+ sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS;
+
+ for (i = 0; i < sma->sem_nsems; i++) {
+ sem = &sma->sems[i];
+ spin_lock(&sem->lock);
+ spin_unlock(&sem->lock);
+ }
+}
+
+/*
+ * Try to leave the mode that disallows simple operations:
+ * Caller must own sem_perm.lock.
+ */
+static void complexmode_tryleave(struct sem_array *sma)
+{
+ if (sma->complex_count) {
+ /* Complex ops are sleeping.
+ * We must stay in complex mode
+ */
+ return;
+ }
+ if (sma->use_global_lock == 1) {
+ /*
+ * Immediately after setting use_global_lock to 0,
+ * a simple op can start. Thus: all memory writes
+ * performed by the current operation must be visible
+ * before we set use_global_lock to 0.
+ */
+ smp_store_release(&sma->use_global_lock, 0);
+ } else {
+ sma->use_global_lock--;
+ }
+}
+
+#define SEM_GLOBAL_LOCK (-1)
+/*
+ * If the request contains only one semaphore operation, and there are
+ * no complex transactions pending, lock only the semaphore involved.
+ * Otherwise, lock the entire semaphore array, since we either have
+ * multiple semaphores in our own semops, or we need to look at
+ * semaphores from other pending complex operations.
+ */
+static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
+ int nsops)
+{
+ struct sem *sem;
+ int idx;
+
+ if (nsops != 1) {
+ /* Complex operation - acquire a full lock */
+ ipc_lock_object(&sma->sem_perm);
+
+ /* Prevent parallel simple ops */
+ complexmode_enter(sma);
+ return SEM_GLOBAL_LOCK;
+ }
+
+ /*
+ * Only one semaphore affected - try to optimize locking.
+ * Optimized locking is possible if no complex operation
+ * is either enqueued or processed right now.
+ *
+ * Both facts are tracked by use_global_mode.
+ */
+ idx = array_index_nospec(sops->sem_num, sma->sem_nsems);
+ sem = &sma->sems[idx];
+
+ /*
+ * Initial check for use_global_lock. Just an optimization,
+ * no locking, no memory barrier.
+ */
+ if (!sma->use_global_lock) {
+ /*
+ * It appears that no complex operation is around.
+ * Acquire the per-semaphore lock.
+ */
+ spin_lock(&sem->lock);
+
+ /* pairs with smp_store_release() */
+ if (!smp_load_acquire(&sma->use_global_lock)) {
+ /* fast path successful! */
+ return sops->sem_num;
+ }
+ spin_unlock(&sem->lock);
+ }
+
+ /* slow path: acquire the full lock */
+ ipc_lock_object(&sma->sem_perm);
+
+ if (sma->use_global_lock == 0) {
+ /*
+ * The use_global_lock mode ended while we waited for
+ * sma->sem_perm.lock. Thus we must switch to locking
+ * with sem->lock.
+ * Unlike in the fast path, there is no need to recheck
+ * sma->use_global_lock after we have acquired sem->lock:
+ * We own sma->sem_perm.lock, thus use_global_lock cannot
+ * change.
+ */
+ spin_lock(&sem->lock);
+
+ ipc_unlock_object(&sma->sem_perm);
+ return sops->sem_num;
+ } else {
+ /*
+ * Not a false alarm, thus continue to use the global lock
+ * mode. No need for complexmode_enter(), this was done by
+ * the caller that has set use_global_mode to non-zero.
+ */
+ return SEM_GLOBAL_LOCK;
+ }
+}
+
+static inline void sem_unlock(struct sem_array *sma, int locknum)
+{
+ if (locknum == SEM_GLOBAL_LOCK) {
+ unmerge_queues(sma);
+ complexmode_tryleave(sma);
+ ipc_unlock_object(&sma->sem_perm);
+ } else {
+ struct sem *sem = &sma->sems[locknum];
+ spin_unlock(&sem->lock);
+ }
+}
+
+/*
+ * sem_lock_(check_) routines are called in the paths where the rwsem
+ * is not held.
+ *
+ * The caller holds the RCU read lock.
+ */
+static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&sem_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
+
+ return container_of(ipcp, struct sem_array, sem_perm);
+}
+
+static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&sem_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
+
+ return container_of(ipcp, struct sem_array, sem_perm);
+}
+
+static inline void sem_lock_and_putref(struct sem_array *sma)
+{
+ sem_lock(sma, NULL, -1);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+}
+
+static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
+{
+ ipc_rmid(&sem_ids(ns), &s->sem_perm);
+}
+
+static struct sem_array *sem_alloc(size_t nsems)
+{
+ struct sem_array *sma;
+ size_t size;
+
+ if (nsems > (INT_MAX - sizeof(*sma)) / sizeof(sma->sems[0]))
+ return NULL;
+
+ size = sizeof(*sma) + nsems * sizeof(sma->sems[0]);
+ sma = kvmalloc(size, GFP_KERNEL);
+ if (unlikely(!sma))
+ return NULL;
+
+ memset(sma, 0, size);
+
+ return sma;
+}
+
+/**
+ * newary - Create a new semaphore set
+ * @ns: namespace
+ * @params: ptr to the structure that contains key, semflg and nsems
+ *
+ * Called with sem_ids.rwsem held (as a writer)
+ */
+static int newary(struct ipc_namespace *ns, struct ipc_params *params)
+{
+ int retval;
+ struct sem_array *sma;
+ key_t key = params->key;
+ int nsems = params->u.nsems;
+ int semflg = params->flg;
+ int i;
+
+ if (!nsems)
+ return -EINVAL;
+ if (ns->used_sems + nsems > ns->sc_semmns)
+ return -ENOSPC;
+
+ sma = sem_alloc(nsems);
+ if (!sma)
+ return -ENOMEM;
+
+ sma->sem_perm.mode = (semflg & S_IRWXUGO);
+ sma->sem_perm.key = key;
+
+ sma->sem_perm.security = NULL;
+ retval = security_sem_alloc(&sma->sem_perm);
+ if (retval) {
+ kvfree(sma);
+ return retval;
+ }
+
+ for (i = 0; i < nsems; i++) {
+ INIT_LIST_HEAD(&sma->sems[i].pending_alter);
+ INIT_LIST_HEAD(&sma->sems[i].pending_const);
+ spin_lock_init(&sma->sems[i].lock);
+ }
+
+ sma->complex_count = 0;
+ sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS;
+ INIT_LIST_HEAD(&sma->pending_alter);
+ INIT_LIST_HEAD(&sma->pending_const);
+ INIT_LIST_HEAD(&sma->list_id);
+ sma->sem_nsems = nsems;
+ sma->sem_ctime = ktime_get_real_seconds();
+
+ /* ipc_addid() locks sma upon success. */
+ retval = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
+ if (retval < 0) {
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+ return retval;
+ }
+ ns->used_sems += nsems;
+
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+
+ return sma->sem_perm.id;
+}
+
+
+/*
+ * Called with sem_ids.rwsem and ipcp locked.
+ */
+static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
+ struct ipc_params *params)
+{
+ struct sem_array *sma;
+
+ sma = container_of(ipcp, struct sem_array, sem_perm);
+ if (params->u.nsems > sma->sem_nsems)
+ return -EINVAL;
+
+ return 0;
+}
+
+long ksys_semget(key_t key, int nsems, int semflg)
+{
+ struct ipc_namespace *ns;
+ static const struct ipc_ops sem_ops = {
+ .getnew = newary,
+ .associate = security_sem_associate,
+ .more_checks = sem_more_checks,
+ };
+ struct ipc_params sem_params;
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (nsems < 0 || nsems > ns->sc_semmsl)
+ return -EINVAL;
+
+ sem_params.key = key;
+ sem_params.flg = semflg;
+ sem_params.u.nsems = nsems;
+
+ return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
+}
+
+SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
+{
+ return ksys_semget(key, nsems, semflg);
+}
+
+/**
+ * perform_atomic_semop[_slow] - Attempt to perform semaphore
+ * operations on a given array.
+ * @sma: semaphore array
+ * @q: struct sem_queue that describes the operation
+ *
+ * Caller blocking are as follows, based the value
+ * indicated by the semaphore operation (sem_op):
+ *
+ * (1) >0 never blocks.
+ * (2) 0 (wait-for-zero operation): semval is non-zero.
+ * (3) <0 attempting to decrement semval to a value smaller than zero.
+ *
+ * Returns 0 if the operation was possible.
+ * Returns 1 if the operation is impossible, the caller must sleep.
+ * Returns <0 for error codes.
+ */
+static int perform_atomic_semop_slow(struct sem_array *sma, struct sem_queue *q)
+{
+ int result, sem_op, nsops;
+ struct pid *pid;
+ struct sembuf *sop;
+ struct sem *curr;
+ struct sembuf *sops;
+ struct sem_undo *un;
+
+ sops = q->sops;
+ nsops = q->nsops;
+ un = q->undo;
+
+ for (sop = sops; sop < sops + nsops; sop++) {
+ int idx = array_index_nospec(sop->sem_num, sma->sem_nsems);
+ curr = &sma->sems[idx];
+ sem_op = sop->sem_op;
+ result = curr->semval;
+
+ if (!sem_op && result)
+ goto would_block;
+
+ result += sem_op;
+ if (result < 0)
+ goto would_block;
+ if (result > SEMVMX)
+ goto out_of_range;
+
+ if (sop->sem_flg & SEM_UNDO) {
+ int undo = un->semadj[sop->sem_num] - sem_op;
+ /* Exceeding the undo range is an error. */
+ if (undo < (-SEMAEM - 1) || undo > SEMAEM)
+ goto out_of_range;
+ un->semadj[sop->sem_num] = undo;
+ }
+
+ curr->semval = result;
+ }
+
+ sop--;
+ pid = q->pid;
+ while (sop >= sops) {
+ ipc_update_pid(&sma->sems[sop->sem_num].sempid, pid);
+ sop--;
+ }
+
+ return 0;
+
+out_of_range:
+ result = -ERANGE;
+ goto undo;
+
+would_block:
+ q->blocking = sop;
+
+ if (sop->sem_flg & IPC_NOWAIT)
+ result = -EAGAIN;
+ else
+ result = 1;
+
+undo:
+ sop--;
+ while (sop >= sops) {
+ sem_op = sop->sem_op;
+ sma->sems[sop->sem_num].semval -= sem_op;
+ if (sop->sem_flg & SEM_UNDO)
+ un->semadj[sop->sem_num] += sem_op;
+ sop--;
+ }
+
+ return result;
+}
+
+static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
+{
+ int result, sem_op, nsops;
+ struct sembuf *sop;
+ struct sem *curr;
+ struct sembuf *sops;
+ struct sem_undo *un;
+
+ sops = q->sops;
+ nsops = q->nsops;
+ un = q->undo;
+
+ if (unlikely(q->dupsop))
+ return perform_atomic_semop_slow(sma, q);
+
+ /*
+ * We scan the semaphore set twice, first to ensure that the entire
+ * operation can succeed, therefore avoiding any pointless writes
+ * to shared memory and having to undo such changes in order to block
+ * until the operations can go through.
+ */
+ for (sop = sops; sop < sops + nsops; sop++) {
+ int idx = array_index_nospec(sop->sem_num, sma->sem_nsems);
+
+ curr = &sma->sems[idx];
+ sem_op = sop->sem_op;
+ result = curr->semval;
+
+ if (!sem_op && result)
+ goto would_block; /* wait-for-zero */
+
+ result += sem_op;
+ if (result < 0)
+ goto would_block;
+
+ if (result > SEMVMX)
+ return -ERANGE;
+
+ if (sop->sem_flg & SEM_UNDO) {
+ int undo = un->semadj[sop->sem_num] - sem_op;
+
+ /* Exceeding the undo range is an error. */
+ if (undo < (-SEMAEM - 1) || undo > SEMAEM)
+ return -ERANGE;
+ }
+ }
+
+ for (sop = sops; sop < sops + nsops; sop++) {
+ curr = &sma->sems[sop->sem_num];
+ sem_op = sop->sem_op;
+ result = curr->semval;
+
+ if (sop->sem_flg & SEM_UNDO) {
+ int undo = un->semadj[sop->sem_num] - sem_op;
+
+ un->semadj[sop->sem_num] = undo;
+ }
+ curr->semval += sem_op;
+ ipc_update_pid(&curr->sempid, q->pid);
+ }
+
+ return 0;
+
+would_block:
+ q->blocking = sop;
+ return sop->sem_flg & IPC_NOWAIT ? -EAGAIN : 1;
+}
+
+static inline void wake_up_sem_queue_prepare(struct sem_queue *q, int error,
+ struct wake_q_head *wake_q)
+{
+ wake_q_add(wake_q, q->sleeper);
+ /*
+ * Rely on the above implicit barrier, such that we can
+ * ensure that we hold reference to the task before setting
+ * q->status. Otherwise we could race with do_exit if the
+ * task is awoken by an external event before calling
+ * wake_up_process().
+ */
+ WRITE_ONCE(q->status, error);
+}
+
+static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
+{
+ list_del(&q->list);
+ if (q->nsops > 1)
+ sma->complex_count--;
+}
+
+/** check_restart(sma, q)
+ * @sma: semaphore array
+ * @q: the operation that just completed
+ *
+ * update_queue is O(N^2) when it restarts scanning the whole queue of
+ * waiting operations. Therefore this function checks if the restart is
+ * really necessary. It is called after a previously waiting operation
+ * modified the array.
+ * Note that wait-for-zero operations are handled without restart.
+ */
+static inline int check_restart(struct sem_array *sma, struct sem_queue *q)
+{
+ /* pending complex alter operations are too difficult to analyse */
+ if (!list_empty(&sma->pending_alter))
+ return 1;
+
+ /* we were a sleeping complex operation. Too difficult */
+ if (q->nsops > 1)
+ return 1;
+
+ /* It is impossible that someone waits for the new value:
+ * - complex operations always restart.
+ * - wait-for-zero are handled seperately.
+ * - q is a previously sleeping simple operation that
+ * altered the array. It must be a decrement, because
+ * simple increments never sleep.
+ * - If there are older (higher priority) decrements
+ * in the queue, then they have observed the original
+ * semval value and couldn't proceed. The operation
+ * decremented to value - thus they won't proceed either.
+ */
+ return 0;
+}
+
+/**
+ * wake_const_ops - wake up non-alter tasks
+ * @sma: semaphore array.
+ * @semnum: semaphore that was modified.
+ * @wake_q: lockless wake-queue head.
+ *
+ * wake_const_ops must be called after a semaphore in a semaphore array
+ * was set to 0. If complex const operations are pending, wake_const_ops must
+ * be called with semnum = -1, as well as with the number of each modified
+ * semaphore.
+ * The tasks that must be woken up are added to @wake_q. The return code
+ * is stored in q->pid.
+ * The function returns 1 if at least one operation was completed successfully.
+ */
+static int wake_const_ops(struct sem_array *sma, int semnum,
+ struct wake_q_head *wake_q)
+{
+ struct sem_queue *q, *tmp;
+ struct list_head *pending_list;
+ int semop_completed = 0;
+
+ if (semnum == -1)
+ pending_list = &sma->pending_const;
+ else
+ pending_list = &sma->sems[semnum].pending_const;
+
+ list_for_each_entry_safe(q, tmp, pending_list, list) {
+ int error = perform_atomic_semop(sma, q);
+
+ if (error > 0)
+ continue;
+ /* operation completed, remove from queue & wakeup */
+ unlink_queue(sma, q);
+
+ wake_up_sem_queue_prepare(q, error, wake_q);
+ if (error == 0)
+ semop_completed = 1;
+ }
+
+ return semop_completed;
+}
+
+/**
+ * do_smart_wakeup_zero - wakeup all wait for zero tasks
+ * @sma: semaphore array
+ * @sops: operations that were performed
+ * @nsops: number of operations
+ * @wake_q: lockless wake-queue head
+ *
+ * Checks all required queue for wait-for-zero operations, based
+ * on the actual changes that were performed on the semaphore array.
+ * The function returns 1 if at least one operation was completed successfully.
+ */
+static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
+ int nsops, struct wake_q_head *wake_q)
+{
+ int i;
+ int semop_completed = 0;
+ int got_zero = 0;
+
+ /* first: the per-semaphore queues, if known */
+ if (sops) {
+ for (i = 0; i < nsops; i++) {
+ int num = sops[i].sem_num;
+
+ if (sma->sems[num].semval == 0) {
+ got_zero = 1;
+ semop_completed |= wake_const_ops(sma, num, wake_q);
+ }
+ }
+ } else {
+ /*
+ * No sops means modified semaphores not known.
+ * Assume all were changed.
+ */
+ for (i = 0; i < sma->sem_nsems; i++) {
+ if (sma->sems[i].semval == 0) {
+ got_zero = 1;
+ semop_completed |= wake_const_ops(sma, i, wake_q);
+ }
+ }
+ }
+ /*
+ * If one of the modified semaphores got 0,
+ * then check the global queue, too.
+ */
+ if (got_zero)
+ semop_completed |= wake_const_ops(sma, -1, wake_q);
+
+ return semop_completed;
+}
+
+
+/**
+ * update_queue - look for tasks that can be completed.
+ * @sma: semaphore array.
+ * @semnum: semaphore that was modified.
+ * @wake_q: lockless wake-queue head.
+ *
+ * update_queue must be called after a semaphore in a semaphore array
+ * was modified. If multiple semaphores were modified, update_queue must
+ * be called with semnum = -1, as well as with the number of each modified
+ * semaphore.
+ * The tasks that must be woken up are added to @wake_q. The return code
+ * is stored in q->pid.
+ * The function internally checks if const operations can now succeed.
+ *
+ * The function return 1 if at least one semop was completed successfully.
+ */
+static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *wake_q)
+{
+ struct sem_queue *q, *tmp;
+ struct list_head *pending_list;
+ int semop_completed = 0;
+
+ if (semnum == -1)
+ pending_list = &sma->pending_alter;
+ else
+ pending_list = &sma->sems[semnum].pending_alter;
+
+again:
+ list_for_each_entry_safe(q, tmp, pending_list, list) {
+ int error, restart;
+
+ /* If we are scanning the single sop, per-semaphore list of
+ * one semaphore and that semaphore is 0, then it is not
+ * necessary to scan further: simple increments
+ * that affect only one entry succeed immediately and cannot
+ * be in the per semaphore pending queue, and decrements
+ * cannot be successful if the value is already 0.
+ */
+ if (semnum != -1 && sma->sems[semnum].semval == 0)
+ break;
+
+ error = perform_atomic_semop(sma, q);
+
+ /* Does q->sleeper still need to sleep? */
+ if (error > 0)
+ continue;
+
+ unlink_queue(sma, q);
+
+ if (error) {
+ restart = 0;
+ } else {
+ semop_completed = 1;
+ do_smart_wakeup_zero(sma, q->sops, q->nsops, wake_q);
+ restart = check_restart(sma, q);
+ }
+
+ wake_up_sem_queue_prepare(q, error, wake_q);
+ if (restart)
+ goto again;
+ }
+ return semop_completed;
+}
+
+/**
+ * set_semotime - set sem_otime
+ * @sma: semaphore array
+ * @sops: operations that modified the array, may be NULL
+ *
+ * sem_otime is replicated to avoid cache line trashing.
+ * This function sets one instance to the current time.
+ */
+static void set_semotime(struct sem_array *sma, struct sembuf *sops)
+{
+ if (sops == NULL) {
+ sma->sems[0].sem_otime = ktime_get_real_seconds();
+ } else {
+ sma->sems[sops[0].sem_num].sem_otime =
+ ktime_get_real_seconds();
+ }
+}
+
+/**
+ * do_smart_update - optimized update_queue
+ * @sma: semaphore array
+ * @sops: operations that were performed
+ * @nsops: number of operations
+ * @otime: force setting otime
+ * @wake_q: lockless wake-queue head
+ *
+ * do_smart_update() does the required calls to update_queue and wakeup_zero,
+ * based on the actual changes that were performed on the semaphore array.
+ * Note that the function does not do the actual wake-up: the caller is
+ * responsible for calling wake_up_q().
+ * It is safe to perform this call after dropping all locks.
+ */
+static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsops,
+ int otime, struct wake_q_head *wake_q)
+{
+ int i;
+
+ otime |= do_smart_wakeup_zero(sma, sops, nsops, wake_q);
+
+ if (!list_empty(&sma->pending_alter)) {
+ /* semaphore array uses the global queue - just process it. */
+ otime |= update_queue(sma, -1, wake_q);
+ } else {
+ if (!sops) {
+ /*
+ * No sops, thus the modified semaphores are not
+ * known. Check all.
+ */
+ for (i = 0; i < sma->sem_nsems; i++)
+ otime |= update_queue(sma, i, wake_q);
+ } else {
+ /*
+ * Check the semaphores that were increased:
+ * - No complex ops, thus all sleeping ops are
+ * decrease.
+ * - if we decreased the value, then any sleeping
+ * semaphore ops wont be able to run: If the
+ * previous value was too small, then the new
+ * value will be too small, too.
+ */
+ for (i = 0; i < nsops; i++) {
+ if (sops[i].sem_op > 0) {
+ otime |= update_queue(sma,
+ sops[i].sem_num, wake_q);
+ }
+ }
+ }
+ }
+ if (otime)
+ set_semotime(sma, sops);
+}
+
+/*
+ * check_qop: Test if a queued operation sleeps on the semaphore semnum
+ */
+static int check_qop(struct sem_array *sma, int semnum, struct sem_queue *q,
+ bool count_zero)
+{
+ struct sembuf *sop = q->blocking;
+
+ /*
+ * Linux always (since 0.99.10) reported a task as sleeping on all
+ * semaphores. This violates SUS, therefore it was changed to the
+ * standard compliant behavior.
+ * Give the administrators a chance to notice that an application
+ * might misbehave because it relies on the Linux behavior.
+ */
+ pr_info_once("semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant.\n"
+ "The task %s (%d) triggered the difference, watch for misbehavior.\n",
+ current->comm, task_pid_nr(current));
+
+ if (sop->sem_num != semnum)
+ return 0;
+
+ if (count_zero && sop->sem_op == 0)
+ return 1;
+ if (!count_zero && sop->sem_op < 0)
+ return 1;
+
+ return 0;
+}
+
+/* The following counts are associated to each semaphore:
+ * semncnt number of tasks waiting on semval being nonzero
+ * semzcnt number of tasks waiting on semval being zero
+ *
+ * Per definition, a task waits only on the semaphore of the first semop
+ * that cannot proceed, even if additional operation would block, too.
+ */
+static int count_semcnt(struct sem_array *sma, ushort semnum,
+ bool count_zero)
+{
+ struct list_head *l;
+ struct sem_queue *q;
+ int semcnt;
+
+ semcnt = 0;
+ /* First: check the simple operations. They are easy to evaluate */
+ if (count_zero)
+ l = &sma->sems[semnum].pending_const;
+ else
+ l = &sma->sems[semnum].pending_alter;
+
+ list_for_each_entry(q, l, list) {
+ /* all task on a per-semaphore list sleep on exactly
+ * that semaphore
+ */
+ semcnt++;
+ }
+
+ /* Then: check the complex operations. */
+ list_for_each_entry(q, &sma->pending_alter, list) {
+ semcnt += check_qop(sma, semnum, q, count_zero);
+ }
+ if (count_zero) {
+ list_for_each_entry(q, &sma->pending_const, list) {
+ semcnt += check_qop(sma, semnum, q, count_zero);
+ }
+ }
+ return semcnt;
+}
+
+/* Free a semaphore set. freeary() is called with sem_ids.rwsem locked
+ * as a writer and the spinlock for this semaphore set hold. sem_ids.rwsem
+ * remains locked on exit.
+ */
+static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
+{
+ struct sem_undo *un, *tu;
+ struct sem_queue *q, *tq;
+ struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
+ int i;
+ DEFINE_WAKE_Q(wake_q);
+
+ /* Free the existing undo structures for this semaphore set. */
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_for_each_entry_safe(un, tu, &sma->list_id, list_id) {
+ list_del(&un->list_id);
+ spin_lock(&un->ulp->lock);
+ un->semid = -1;
+ list_del_rcu(&un->list_proc);
+ spin_unlock(&un->ulp->lock);
+ kfree_rcu(un, rcu);
+ }
+
+ /* Wake up all pending processes and let them fail with EIDRM. */
+ list_for_each_entry_safe(q, tq, &sma->pending_const, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
+ }
+
+ list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
+ }
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *sem = &sma->sems[i];
+ list_for_each_entry_safe(q, tq, &sem->pending_const, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
+ }
+ list_for_each_entry_safe(q, tq, &sem->pending_alter, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
+ }
+ ipc_update_pid(&sem->sempid, NULL);
+ }
+
+ /* Remove the semaphore set from the IDR */
+ sem_rmid(ns, sma);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+
+ wake_up_q(&wake_q);
+ ns->used_sems -= sma->sem_nsems;
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+}
+
+static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
+{
+ switch (version) {
+ case IPC_64:
+ return copy_to_user(buf, in, sizeof(*in));
+ case IPC_OLD:
+ {
+ struct semid_ds out;
+
+ memset(&out, 0, sizeof(out));
+
+ ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm);
+
+ out.sem_otime = in->sem_otime;
+ out.sem_ctime = in->sem_ctime;
+ out.sem_nsems = in->sem_nsems;
+
+ return copy_to_user(buf, &out, sizeof(out));
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static time64_t get_semotime(struct sem_array *sma)
+{
+ int i;
+ time64_t res;
+
+ res = sma->sems[0].sem_otime;
+ for (i = 1; i < sma->sem_nsems; i++) {
+ time64_t to = sma->sems[i].sem_otime;
+
+ if (to > res)
+ res = to;
+ }
+ return res;
+}
+
+static int semctl_stat(struct ipc_namespace *ns, int semid,
+ int cmd, struct semid64_ds *semid64)
+{
+ struct sem_array *sma;
+ time64_t semotime;
+ int err;
+
+ memset(semid64, 0, sizeof(*semid64));
+
+ rcu_read_lock();
+ if (cmd == SEM_STAT || cmd == SEM_STAT_ANY) {
+ sma = sem_obtain_object(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
+ goto out_unlock;
+ }
+ } else { /* IPC_STAT */
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
+ goto out_unlock;
+ }
+ }
+
+ /* see comment for SHM_STAT_ANY */
+ if (cmd == SEM_STAT_ANY)
+ audit_ipc_obj(&sma->sem_perm);
+ else {
+ err = -EACCES;
+ if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
+ goto out_unlock;
+ }
+
+ err = security_sem_semctl(&sma->sem_perm, cmd);
+ if (err)
+ goto out_unlock;
+
+ ipc_lock_object(&sma->sem_perm);
+
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ ipc_unlock_object(&sma->sem_perm);
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ kernel_to_ipc64_perm(&sma->sem_perm, &semid64->sem_perm);
+ semotime = get_semotime(sma);
+ semid64->sem_otime = semotime;
+ semid64->sem_ctime = sma->sem_ctime;
+#ifndef CONFIG_64BIT
+ semid64->sem_otime_high = semotime >> 32;
+ semid64->sem_ctime_high = sma->sem_ctime >> 32;
+#endif
+ semid64->sem_nsems = sma->sem_nsems;
+
+ if (cmd == IPC_STAT) {
+ /*
+ * As defined in SUS:
+ * Return 0 on success
+ */
+ err = 0;
+ } else {
+ /*
+ * SEM_STAT and SEM_STAT_ANY (both Linux specific)
+ * Return the full id, including the sequence number
+ */
+ err = sma->sem_perm.id;
+ }
+ ipc_unlock_object(&sma->sem_perm);
+out_unlock:
+ rcu_read_unlock();
+ return err;
+}
+
+static int semctl_info(struct ipc_namespace *ns, int semid,
+ int cmd, void __user *p)
+{
+ struct seminfo seminfo;
+ int max_idx;
+ int err;
+
+ err = security_sem_semctl(NULL, cmd);
+ if (err)
+ return err;
+
+ memset(&seminfo, 0, sizeof(seminfo));
+ seminfo.semmni = ns->sc_semmni;
+ seminfo.semmns = ns->sc_semmns;
+ seminfo.semmsl = ns->sc_semmsl;
+ seminfo.semopm = ns->sc_semopm;
+ seminfo.semvmx = SEMVMX;
+ seminfo.semmnu = SEMMNU;
+ seminfo.semmap = SEMMAP;
+ seminfo.semume = SEMUME;
+ down_read(&sem_ids(ns).rwsem);
+ if (cmd == SEM_INFO) {
+ seminfo.semusz = sem_ids(ns).in_use;
+ seminfo.semaem = ns->used_sems;
+ } else {
+ seminfo.semusz = SEMUSZ;
+ seminfo.semaem = SEMAEM;
+ }
+ max_idx = ipc_get_maxidx(&sem_ids(ns));
+ up_read(&sem_ids(ns).rwsem);
+ if (copy_to_user(p, &seminfo, sizeof(struct seminfo)))
+ return -EFAULT;
+ return (max_idx < 0) ? 0 : max_idx;
+}
+
+static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
+ int val)
+{
+ struct sem_undo *un;
+ struct sem_array *sma;
+ struct sem *curr;
+ int err;
+ DEFINE_WAKE_Q(wake_q);
+
+ if (val > SEMVMX || val < 0)
+ return -ERANGE;
+
+ rcu_read_lock();
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ return PTR_ERR(sma);
+ }
+
+ if (semnum < 0 || semnum >= sma->sem_nsems) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+
+ if (ipcperms(ns, &sma->sem_perm, S_IWUGO)) {
+ rcu_read_unlock();
+ return -EACCES;
+ }
+
+ err = security_sem_semctl(&sma->sem_perm, SETVAL);
+ if (err) {
+ rcu_read_unlock();
+ return -EACCES;
+ }
+
+ sem_lock(sma, NULL, -1);
+
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ return -EIDRM;
+ }
+
+ semnum = array_index_nospec(semnum, sma->sem_nsems);
+ curr = &sma->sems[semnum];
+
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_for_each_entry(un, &sma->list_id, list_id)
+ un->semadj[semnum] = 0;
+
+ curr->semval = val;
+ ipc_update_pid(&curr->sempid, task_tgid(current));
+ sma->sem_ctime = ktime_get_real_seconds();
+ /* maybe some queued-up processes were waiting for this */
+ do_smart_update(sma, NULL, 0, 0, &wake_q);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ wake_up_q(&wake_q);
+ return 0;
+}
+
+static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
+ int cmd, void __user *p)
+{
+ struct sem_array *sma;
+ struct sem *curr;
+ int err, nsems;
+ ushort fast_sem_io[SEMMSL_FAST];
+ ushort *sem_io = fast_sem_io;
+ DEFINE_WAKE_Q(wake_q);
+
+ rcu_read_lock();
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ return PTR_ERR(sma);
+ }
+
+ nsems = sma->sem_nsems;
+
+ err = -EACCES;
+ if (ipcperms(ns, &sma->sem_perm, cmd == SETALL ? S_IWUGO : S_IRUGO))
+ goto out_rcu_wakeup;
+
+ err = security_sem_semctl(&sma->sem_perm, cmd);
+ if (err)
+ goto out_rcu_wakeup;
+
+ err = -EACCES;
+ switch (cmd) {
+ case GETALL:
+ {
+ ushort __user *array = p;
+ int i;
+
+ sem_lock(sma, NULL, -1);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+ if (nsems > SEMMSL_FAST) {
+ if (!ipc_rcu_getref(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ sem_io = kvmalloc_array(nsems, sizeof(ushort),
+ GFP_KERNEL);
+ if (sem_io == NULL) {
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+ return -ENOMEM;
+ }
+
+ rcu_read_lock();
+ sem_lock_and_putref(sma);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+ }
+ for (i = 0; i < sma->sem_nsems; i++)
+ sem_io[i] = sma->sems[i].semval;
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ err = 0;
+ if (copy_to_user(array, sem_io, nsems*sizeof(ushort)))
+ err = -EFAULT;
+ goto out_free;
+ }
+ case SETALL:
+ {
+ int i;
+ struct sem_undo *un;
+
+ if (!ipc_rcu_getref(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_rcu_wakeup;
+ }
+ rcu_read_unlock();
+
+ if (nsems > SEMMSL_FAST) {
+ sem_io = kvmalloc_array(nsems, sizeof(ushort),
+ GFP_KERNEL);
+ if (sem_io == NULL) {
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+ return -ENOMEM;
+ }
+ }
+
+ if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) {
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+ err = -EFAULT;
+ goto out_free;
+ }
+
+ for (i = 0; i < nsems; i++) {
+ if (sem_io[i] > SEMVMX) {
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+ err = -ERANGE;
+ goto out_free;
+ }
+ }
+ rcu_read_lock();
+ sem_lock_and_putref(sma);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ for (i = 0; i < nsems; i++) {
+ sma->sems[i].semval = sem_io[i];
+ ipc_update_pid(&sma->sems[i].sempid, task_tgid(current));
+ }
+
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_for_each_entry(un, &sma->list_id, list_id) {
+ for (i = 0; i < nsems; i++)
+ un->semadj[i] = 0;
+ }
+ sma->sem_ctime = ktime_get_real_seconds();
+ /* maybe some queued-up processes were waiting for this */
+ do_smart_update(sma, NULL, 0, 0, &wake_q);
+ err = 0;
+ goto out_unlock;
+ }
+ /* GETVAL, GETPID, GETNCTN, GETZCNT: fall-through */
+ }
+ err = -EINVAL;
+ if (semnum < 0 || semnum >= nsems)
+ goto out_rcu_wakeup;
+
+ sem_lock(sma, NULL, -1);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ semnum = array_index_nospec(semnum, nsems);
+ curr = &sma->sems[semnum];
+
+ switch (cmd) {
+ case GETVAL:
+ err = curr->semval;
+ goto out_unlock;
+ case GETPID:
+ err = pid_vnr(curr->sempid);
+ goto out_unlock;
+ case GETNCNT:
+ err = count_semcnt(sma, semnum, 0);
+ goto out_unlock;
+ case GETZCNT:
+ err = count_semcnt(sma, semnum, 1);
+ goto out_unlock;
+ }
+
+out_unlock:
+ sem_unlock(sma, -1);
+out_rcu_wakeup:
+ rcu_read_unlock();
+ wake_up_q(&wake_q);
+out_free:
+ if (sem_io != fast_sem_io)
+ kvfree(sem_io);
+ return err;
+}
+
+static inline unsigned long
+copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
+{
+ switch (version) {
+ case IPC_64:
+ if (copy_from_user(out, buf, sizeof(*out)))
+ return -EFAULT;
+ return 0;
+ case IPC_OLD:
+ {
+ struct semid_ds tbuf_old;
+
+ if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+ return -EFAULT;
+
+ out->sem_perm.uid = tbuf_old.sem_perm.uid;
+ out->sem_perm.gid = tbuf_old.sem_perm.gid;
+ out->sem_perm.mode = tbuf_old.sem_perm.mode;
+
+ return 0;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * This function handles some semctl commands which require the rwsem
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
+ */
+static int semctl_down(struct ipc_namespace *ns, int semid,
+ int cmd, struct semid64_ds *semid64)
+{
+ struct sem_array *sma;
+ int err;
+ struct kern_ipc_perm *ipcp;
+
+ down_write(&sem_ids(ns).rwsem);
+ rcu_read_lock();
+
+ ipcp = ipcctl_obtain_check(ns, &sem_ids(ns), semid, cmd,
+ &semid64->sem_perm, 0);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto out_unlock1;
+ }
+
+ sma = container_of(ipcp, struct sem_array, sem_perm);
+
+ err = security_sem_semctl(&sma->sem_perm, cmd);
+ if (err)
+ goto out_unlock1;
+
+ switch (cmd) {
+ case IPC_RMID:
+ sem_lock(sma, NULL, -1);
+ /* freeary unlocks the ipc object and rcu */
+ freeary(ns, ipcp);
+ goto out_up;
+ case IPC_SET:
+ sem_lock(sma, NULL, -1);
+ err = ipc_update_perm(&semid64->sem_perm, ipcp);
+ if (err)
+ goto out_unlock0;
+ sma->sem_ctime = ktime_get_real_seconds();
+ break;
+ default:
+ err = -EINVAL;
+ goto out_unlock1;
+ }
+
+out_unlock0:
+ sem_unlock(sma, -1);
+out_unlock1:
+ rcu_read_unlock();
+out_up:
+ up_write(&sem_ids(ns).rwsem);
+ return err;
+}
+
+long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
+{
+ int version;
+ struct ipc_namespace *ns;
+ void __user *p = (void __user *)arg;
+ struct semid64_ds semid64;
+ int err;
+
+ if (semid < 0)
+ return -EINVAL;
+
+ version = ipc_parse_version(&cmd);
+ ns = current->nsproxy->ipc_ns;
+
+ switch (cmd) {
+ case IPC_INFO:
+ case SEM_INFO:
+ return semctl_info(ns, semid, cmd, p);
+ case IPC_STAT:
+ case SEM_STAT:
+ case SEM_STAT_ANY:
+ err = semctl_stat(ns, semid, cmd, &semid64);
+ if (err < 0)
+ return err;
+ if (copy_semid_to_user(p, &semid64, version))
+ err = -EFAULT;
+ return err;
+ case GETALL:
+ case GETVAL:
+ case GETPID:
+ case GETNCNT:
+ case GETZCNT:
+ case SETALL:
+ return semctl_main(ns, semid, semnum, cmd, p);
+ case SETVAL: {
+ int val;
+#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
+ /* big-endian 64bit */
+ val = arg >> 32;
+#else
+ /* 32bit or little-endian 64bit */
+ val = arg;
+#endif
+ return semctl_setval(ns, semid, semnum, val);
+ }
+ case IPC_SET:
+ if (copy_semid_from_user(&semid64, p, version))
+ return -EFAULT;
+ case IPC_RMID:
+ return semctl_down(ns, semid, cmd, &semid64);
+ default:
+ return -EINVAL;
+ }
+}
+
+SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
+{
+ return ksys_semctl(semid, semnum, cmd, arg);
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_semid_ds {
+ struct compat_ipc_perm sem_perm;
+ compat_time_t sem_otime;
+ compat_time_t sem_ctime;
+ compat_uptr_t sem_base;
+ compat_uptr_t sem_pending;
+ compat_uptr_t sem_pending_last;
+ compat_uptr_t undo;
+ unsigned short sem_nsems;
+};
+
+static int copy_compat_semid_from_user(struct semid64_ds *out, void __user *buf,
+ int version)
+{
+ memset(out, 0, sizeof(*out));
+ if (version == IPC_64) {
+ struct compat_semid64_ds __user *p = buf;
+ return get_compat_ipc64_perm(&out->sem_perm, &p->sem_perm);
+ } else {
+ struct compat_semid_ds __user *p = buf;
+ return get_compat_ipc_perm(&out->sem_perm, &p->sem_perm);
+ }
+}
+
+static int copy_compat_semid_to_user(void __user *buf, struct semid64_ds *in,
+ int version)
+{
+ if (version == IPC_64) {
+ struct compat_semid64_ds v;
+ memset(&v, 0, sizeof(v));
+ to_compat_ipc64_perm(&v.sem_perm, &in->sem_perm);
+ v.sem_otime = lower_32_bits(in->sem_otime);
+ v.sem_otime_high = upper_32_bits(in->sem_otime);
+ v.sem_ctime = lower_32_bits(in->sem_ctime);
+ v.sem_ctime_high = upper_32_bits(in->sem_ctime);
+ v.sem_nsems = in->sem_nsems;
+ return copy_to_user(buf, &v, sizeof(v));
+ } else {
+ struct compat_semid_ds v;
+ memset(&v, 0, sizeof(v));
+ to_compat_ipc_perm(&v.sem_perm, &in->sem_perm);
+ v.sem_otime = in->sem_otime;
+ v.sem_ctime = in->sem_ctime;
+ v.sem_nsems = in->sem_nsems;
+ return copy_to_user(buf, &v, sizeof(v));
+ }
+}
+
+long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
+{
+ void __user *p = compat_ptr(arg);
+ struct ipc_namespace *ns;
+ struct semid64_ds semid64;
+ int version = compat_ipc_parse_version(&cmd);
+ int err;
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (semid < 0)
+ return -EINVAL;
+
+ switch (cmd & (~IPC_64)) {
+ case IPC_INFO:
+ case SEM_INFO:
+ return semctl_info(ns, semid, cmd, p);
+ case IPC_STAT:
+ case SEM_STAT:
+ case SEM_STAT_ANY:
+ err = semctl_stat(ns, semid, cmd, &semid64);
+ if (err < 0)
+ return err;
+ if (copy_compat_semid_to_user(p, &semid64, version))
+ err = -EFAULT;
+ return err;
+ case GETVAL:
+ case GETPID:
+ case GETNCNT:
+ case GETZCNT:
+ case GETALL:
+ case SETALL:
+ return semctl_main(ns, semid, semnum, cmd, p);
+ case SETVAL:
+ return semctl_setval(ns, semid, semnum, arg);
+ case IPC_SET:
+ if (copy_compat_semid_from_user(&semid64, p, version))
+ return -EFAULT;
+ /* fallthru */
+ case IPC_RMID:
+ return semctl_down(ns, semid, cmd, &semid64);
+ default:
+ return -EINVAL;
+ }
+}
+
+COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
+{
+ return compat_ksys_semctl(semid, semnum, cmd, arg);
+}
+#endif
+
+/* If the task doesn't already have a undo_list, then allocate one
+ * here. We guarantee there is only one thread using this undo list,
+ * and current is THE ONE
+ *
+ * If this allocation and assignment succeeds, but later
+ * portions of this code fail, there is no need to free the sem_undo_list.
+ * Just let it stay associated with the task, and it'll be freed later
+ * at exit time.
+ *
+ * This can block, so callers must hold no locks.
+ */
+static inline int get_undo_list(struct sem_undo_list **undo_listp)
+{
+ struct sem_undo_list *undo_list;
+
+ undo_list = current->sysvsem.undo_list;
+ if (!undo_list) {
+ undo_list = kzalloc(sizeof(*undo_list), GFP_KERNEL);
+ if (undo_list == NULL)
+ return -ENOMEM;
+ spin_lock_init(&undo_list->lock);
+ refcount_set(&undo_list->refcnt, 1);
+ INIT_LIST_HEAD(&undo_list->list_proc);
+
+ current->sysvsem.undo_list = undo_list;
+ }
+ *undo_listp = undo_list;
+ return 0;
+}
+
+static struct sem_undo *__lookup_undo(struct sem_undo_list *ulp, int semid)
+{
+ struct sem_undo *un;
+
+ list_for_each_entry_rcu(un, &ulp->list_proc, list_proc) {
+ if (un->semid == semid)
+ return un;
+ }
+ return NULL;
+}
+
+static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
+{
+ struct sem_undo *un;
+
+ assert_spin_locked(&ulp->lock);
+
+ un = __lookup_undo(ulp, semid);
+ if (un) {
+ list_del_rcu(&un->list_proc);
+ list_add_rcu(&un->list_proc, &ulp->list_proc);
+ }
+ return un;
+}
+
+/**
+ * find_alloc_undo - lookup (and if not present create) undo array
+ * @ns: namespace
+ * @semid: semaphore array id
+ *
+ * The function looks up (and if not present creates) the undo structure.
+ * The size of the undo structure depends on the size of the semaphore
+ * array, thus the alloc path is not that straightforward.
+ * Lifetime-rules: sem_undo is rcu-protected, on success, the function
+ * performs a rcu_read_lock().
+ */
+static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
+{
+ struct sem_array *sma;
+ struct sem_undo_list *ulp;
+ struct sem_undo *un, *new;
+ int nsems, error;
+
+ error = get_undo_list(&ulp);
+ if (error)
+ return ERR_PTR(error);
+
+ rcu_read_lock();
+ spin_lock(&ulp->lock);
+ un = lookup_undo(ulp, semid);
+ spin_unlock(&ulp->lock);
+ if (likely(un != NULL))
+ goto out;
+
+ /* no undo structure around - allocate one. */
+ /* step 1: figure out the size of the semaphore array */
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ return ERR_CAST(sma);
+ }
+
+ nsems = sma->sem_nsems;
+ if (!ipc_rcu_getref(&sma->sem_perm)) {
+ rcu_read_unlock();
+ un = ERR_PTR(-EIDRM);
+ goto out;
+ }
+ rcu_read_unlock();
+
+ /* step 2: allocate new undo structure */
+ new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
+ if (!new) {
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* step 3: Acquire the lock on semaphore array */
+ rcu_read_lock();
+ sem_lock_and_putref(sma);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ kfree(new);
+ un = ERR_PTR(-EIDRM);
+ goto out;
+ }
+ spin_lock(&ulp->lock);
+
+ /*
+ * step 4: check for races: did someone else allocate the undo struct?
+ */
+ un = lookup_undo(ulp, semid);
+ if (un) {
+ kfree(new);
+ goto success;
+ }
+ /* step 5: initialize & link new undo structure */
+ new->semadj = (short *) &new[1];
+ new->ulp = ulp;
+ new->semid = semid;
+ assert_spin_locked(&ulp->lock);
+ list_add_rcu(&new->list_proc, &ulp->list_proc);
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_add(&new->list_id, &sma->list_id);
+ un = new;
+
+success:
+ spin_unlock(&ulp->lock);
+ sem_unlock(sma, -1);
+out:
+ return un;
+}
+
+static long do_semtimedop(int semid, struct sembuf __user *tsops,
+ unsigned nsops, const struct timespec64 *timeout)
+{
+ int error = -EINVAL;
+ struct sem_array *sma;
+ struct sembuf fast_sops[SEMOPM_FAST];
+ struct sembuf *sops = fast_sops, *sop;
+ struct sem_undo *un;
+ int max, locknum;
+ bool undos = false, alter = false, dupsop = false;
+ struct sem_queue queue;
+ unsigned long dup = 0, jiffies_left = 0;
+ struct ipc_namespace *ns;
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (nsops < 1 || semid < 0)
+ return -EINVAL;
+ if (nsops > ns->sc_semopm)
+ return -E2BIG;
+ if (nsops > SEMOPM_FAST) {
+ sops = kvmalloc_array(nsops, sizeof(*sops), GFP_KERNEL);
+ if (sops == NULL)
+ return -ENOMEM;
+ }
+
+ if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) {
+ error = -EFAULT;
+ goto out_free;
+ }
+
+ if (timeout) {
+ if (timeout->tv_sec < 0 || timeout->tv_nsec < 0 ||
+ timeout->tv_nsec >= 1000000000L) {
+ error = -EINVAL;
+ goto out_free;
+ }
+ jiffies_left = timespec64_to_jiffies(timeout);
+ }
+
+ max = 0;
+ for (sop = sops; sop < sops + nsops; sop++) {
+ unsigned long mask = 1ULL << ((sop->sem_num) % BITS_PER_LONG);
+
+ if (sop->sem_num >= max)
+ max = sop->sem_num;
+ if (sop->sem_flg & SEM_UNDO)
+ undos = true;
+ if (dup & mask) {
+ /*
+ * There was a previous alter access that appears
+ * to have accessed the same semaphore, thus use
+ * the dupsop logic. "appears", because the detection
+ * can only check % BITS_PER_LONG.
+ */
+ dupsop = true;
+ }
+ if (sop->sem_op != 0) {
+ alter = true;
+ dup |= mask;
+ }
+ }
+
+ if (undos) {
+ /* On success, find_alloc_undo takes the rcu_read_lock */
+ un = find_alloc_undo(ns, semid);
+ if (IS_ERR(un)) {
+ error = PTR_ERR(un);
+ goto out_free;
+ }
+ } else {
+ un = NULL;
+ rcu_read_lock();
+ }
+
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ error = PTR_ERR(sma);
+ goto out_free;
+ }
+
+ error = -EFBIG;
+ if (max >= sma->sem_nsems) {
+ rcu_read_unlock();
+ goto out_free;
+ }
+
+ error = -EACCES;
+ if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) {
+ rcu_read_unlock();
+ goto out_free;
+ }
+
+ error = security_sem_semop(&sma->sem_perm, sops, nsops, alter);
+ if (error) {
+ rcu_read_unlock();
+ goto out_free;
+ }
+
+ error = -EIDRM;
+ locknum = sem_lock(sma, sops, nsops);
+ /*
+ * We eventually might perform the following check in a lockless
+ * fashion, considering ipc_valid_object() locking constraints.
+ * If nsops == 1 and there is no contention for sem_perm.lock, then
+ * only a per-semaphore lock is held and it's OK to proceed with the
+ * check below. More details on the fine grained locking scheme
+ * entangled here and why it's RMID race safe on comments at sem_lock()
+ */
+ if (!ipc_valid_object(&sma->sem_perm))
+ goto out_unlock_free;
+ /*
+ * semid identifiers are not unique - find_alloc_undo may have
+ * allocated an undo structure, it was invalidated by an RMID
+ * and now a new array with received the same id. Check and fail.
+ * This case can be detected checking un->semid. The existence of
+ * "un" itself is guaranteed by rcu.
+ */
+ if (un && un->semid == -1)
+ goto out_unlock_free;
+
+ queue.sops = sops;
+ queue.nsops = nsops;
+ queue.undo = un;
+ queue.pid = task_tgid(current);
+ queue.alter = alter;
+ queue.dupsop = dupsop;
+
+ error = perform_atomic_semop(sma, &queue);
+ if (error == 0) { /* non-blocking succesfull path */
+ DEFINE_WAKE_Q(wake_q);
+
+ /*
+ * If the operation was successful, then do
+ * the required updates.
+ */
+ if (alter)
+ do_smart_update(sma, sops, nsops, 1, &wake_q);
+ else
+ set_semotime(sma, sops);
+
+ sem_unlock(sma, locknum);
+ rcu_read_unlock();
+ wake_up_q(&wake_q);
+
+ goto out_free;
+ }
+ if (error < 0) /* non-blocking error path */
+ goto out_unlock_free;
+
+ /*
+ * We need to sleep on this operation, so we put the current
+ * task into the pending queue and go to sleep.
+ */
+ if (nsops == 1) {
+ struct sem *curr;
+ int idx = array_index_nospec(sops->sem_num, sma->sem_nsems);
+ curr = &sma->sems[idx];
+
+ if (alter) {
+ if (sma->complex_count) {
+ list_add_tail(&queue.list,
+ &sma->pending_alter);
+ } else {
+
+ list_add_tail(&queue.list,
+ &curr->pending_alter);
+ }
+ } else {
+ list_add_tail(&queue.list, &curr->pending_const);
+ }
+ } else {
+ if (!sma->complex_count)
+ merge_queues(sma);
+
+ if (alter)
+ list_add_tail(&queue.list, &sma->pending_alter);
+ else
+ list_add_tail(&queue.list, &sma->pending_const);
+
+ sma->complex_count++;
+ }
+
+ do {
+ WRITE_ONCE(queue.status, -EINTR);
+ queue.sleeper = current;
+
+ __set_current_state(TASK_INTERRUPTIBLE);
+ sem_unlock(sma, locknum);
+ rcu_read_unlock();
+
+ if (timeout)
+ jiffies_left = schedule_timeout(jiffies_left);
+ else
+ schedule();
+
+ /*
+ * fastpath: the semop has completed, either successfully or
+ * not, from the syscall pov, is quite irrelevant to us at this
+ * point; we're done.
+ *
+ * We _do_ care, nonetheless, about being awoken by a signal or
+ * spuriously. The queue.status is checked again in the
+ * slowpath (aka after taking sem_lock), such that we can detect
+ * scenarios where we were awakened externally, during the
+ * window between wake_q_add() and wake_up_q().
+ */
+ error = READ_ONCE(queue.status);
+ if (error != -EINTR) {
+ /*
+ * User space could assume that semop() is a memory
+ * barrier: Without the mb(), the cpu could
+ * speculatively read in userspace stale data that was
+ * overwritten by the previous owner of the semaphore.
+ */
+ smp_mb();
+ goto out_free;
+ }
+
+ rcu_read_lock();
+ locknum = sem_lock(sma, sops, nsops);
+
+ if (!ipc_valid_object(&sma->sem_perm))
+ goto out_unlock_free;
+
+ error = READ_ONCE(queue.status);
+
+ /*
+ * If queue.status != -EINTR we are woken up by another process.
+ * Leave without unlink_queue(), but with sem_unlock().
+ */
+ if (error != -EINTR)
+ goto out_unlock_free;
+
+ /*
+ * If an interrupt occurred we have to clean up the queue.
+ */
+ if (timeout && jiffies_left == 0)
+ error = -EAGAIN;
+ } while (error == -EINTR && !signal_pending(current)); /* spurious */
+
+ unlink_queue(sma, &queue);
+
+out_unlock_free:
+ sem_unlock(sma, locknum);
+ rcu_read_unlock();
+out_free:
+ if (sops != fast_sops)
+ kvfree(sops);
+ return error;
+}
+
+long ksys_semtimedop(int semid, struct sembuf __user *tsops,
+ unsigned int nsops, const struct __kernel_timespec __user *timeout)
+{
+ if (timeout) {
+ struct timespec64 ts;
+ if (get_timespec64(&ts, timeout))
+ return -EFAULT;
+ return do_semtimedop(semid, tsops, nsops, &ts);
+ }
+ return do_semtimedop(semid, tsops, nsops, NULL);
+}
+
+SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
+ unsigned int, nsops, const struct __kernel_timespec __user *, timeout)
+{
+ return ksys_semtimedop(semid, tsops, nsops, timeout);
+}
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
+ unsigned int nsops,
+ const struct compat_timespec __user *timeout)
+{
+ if (timeout) {
+ struct timespec64 ts;
+ if (compat_get_timespec64(&ts, timeout))
+ return -EFAULT;
+ return do_semtimedop(semid, tsems, nsops, &ts);
+ }
+ return do_semtimedop(semid, tsems, nsops, NULL);
+}
+
+COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
+ unsigned int, nsops,
+ const struct compat_timespec __user *, timeout)
+{
+ return compat_ksys_semtimedop(semid, tsems, nsops, timeout);
+}
+#endif
+
+SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops,
+ unsigned, nsops)
+{
+ return do_semtimedop(semid, tsops, nsops, NULL);
+}
+
+/* If CLONE_SYSVSEM is set, establish sharing of SEM_UNDO state between
+ * parent and child tasks.
+ */
+
+int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
+{
+ struct sem_undo_list *undo_list;
+ int error;
+
+ if (clone_flags & CLONE_SYSVSEM) {
+ error = get_undo_list(&undo_list);
+ if (error)
+ return error;
+ refcount_inc(&undo_list->refcnt);
+ tsk->sysvsem.undo_list = undo_list;
+ } else
+ tsk->sysvsem.undo_list = NULL;
+
+ return 0;
+}
+
+/*
+ * add semadj values to semaphores, free undo structures.
+ * undo structures are not freed when semaphore arrays are destroyed
+ * so some of them may be out of date.
+ * IMPLEMENTATION NOTE: There is some confusion over whether the
+ * set of adjustments that needs to be done should be done in an atomic
+ * manner or not. That is, if we are attempting to decrement the semval
+ * should we queue up and wait until we can do so legally?
+ * The original implementation attempted to do this (queue and wait).
+ * The current implementation does not do so. The POSIX standard
+ * and SVID should be consulted to determine what behavior is mandated.
+ */
+void exit_sem(struct task_struct *tsk)
+{
+ struct sem_undo_list *ulp;
+
+ ulp = tsk->sysvsem.undo_list;
+ if (!ulp)
+ return;
+ tsk->sysvsem.undo_list = NULL;
+
+ if (!refcount_dec_and_test(&ulp->refcnt))
+ return;
+
+ for (;;) {
+ struct sem_array *sma;
+ struct sem_undo *un;
+ int semid, i;
+ DEFINE_WAKE_Q(wake_q);
+
+ cond_resched();
+
+ rcu_read_lock();
+ un = list_entry_rcu(ulp->list_proc.next,
+ struct sem_undo, list_proc);
+ if (&un->list_proc == &ulp->list_proc) {
+ /*
+ * We must wait for freeary() before freeing this ulp,
+ * in case we raced with last sem_undo. There is a small
+ * possibility where we exit while freeary() didn't
+ * finish unlocking sem_undo_list.
+ */
+ spin_lock(&ulp->lock);
+ spin_unlock(&ulp->lock);
+ rcu_read_unlock();
+ break;
+ }
+ spin_lock(&ulp->lock);
+ semid = un->semid;
+ spin_unlock(&ulp->lock);
+
+ /* exit_sem raced with IPC_RMID, nothing to do */
+ if (semid == -1) {
+ rcu_read_unlock();
+ continue;
+ }
+
+ sma = sem_obtain_object_check(tsk->nsproxy->ipc_ns, semid);
+ /* exit_sem raced with IPC_RMID, nothing to do */
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ continue;
+ }
+
+ sem_lock(sma, NULL, -1);
+ /* exit_sem raced with IPC_RMID, nothing to do */
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ continue;
+ }
+ un = __lookup_undo(ulp, semid);
+ if (un == NULL) {
+ /* exit_sem raced with IPC_RMID+semget() that created
+ * exactly the same semid. Nothing to do.
+ */
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ continue;
+ }
+
+ /* remove un from the linked lists */
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_del(&un->list_id);
+
+ /* we are the last process using this ulp, acquiring ulp->lock
+ * isn't required. Besides that, we are also protected against
+ * IPC_RMID as we hold sma->sem_perm lock now
+ */
+ list_del_rcu(&un->list_proc);
+
+ /* perform adjustments registered in un */
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *semaphore = &sma->sems[i];
+ if (un->semadj[i]) {
+ semaphore->semval += un->semadj[i];
+ /*
+ * Range checks of the new semaphore value,
+ * not defined by sus:
+ * - Some unices ignore the undo entirely
+ * (e.g. HP UX 11i 11.22, Tru64 V5.1)
+ * - some cap the value (e.g. FreeBSD caps
+ * at 0, but doesn't enforce SEMVMX)
+ *
+ * Linux caps the semaphore value, both at 0
+ * and at SEMVMX.
+ *
+ * Manfred <manfred@colorfullife.com>
+ */
+ if (semaphore->semval < 0)
+ semaphore->semval = 0;
+ if (semaphore->semval > SEMVMX)
+ semaphore->semval = SEMVMX;
+ ipc_update_pid(&semaphore->sempid, task_tgid(current));
+ }
+ }
+ /* maybe some queued-up processes were waiting for this */
+ do_smart_update(sma, NULL, 0, 1, &wake_q);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ wake_up_q(&wake_q);
+
+ kfree_rcu(un, rcu);
+ }
+ kfree(ulp);
+}
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
+{
+ struct user_namespace *user_ns = seq_user_ns(s);
+ struct kern_ipc_perm *ipcp = it;
+ struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
+ time64_t sem_otime;
+
+ /*
+ * The proc interface isn't aware of sem_lock(), it calls
+ * ipc_lock_object() directly (in sysvipc_find_ipc).
+ * In order to stay compatible with sem_lock(), we must
+ * enter / leave complex_mode.
+ */
+ complexmode_enter(sma);
+
+ sem_otime = get_semotime(sma);
+
+ seq_printf(s,
+ "%10d %10d %4o %10u %5u %5u %5u %5u %10llu %10llu\n",
+ sma->sem_perm.key,
+ sma->sem_perm.id,
+ sma->sem_perm.mode,
+ sma->sem_nsems,
+ from_kuid_munged(user_ns, sma->sem_perm.uid),
+ from_kgid_munged(user_ns, sma->sem_perm.gid),
+ from_kuid_munged(user_ns, sma->sem_perm.cuid),
+ from_kgid_munged(user_ns, sma->sem_perm.cgid),
+ sem_otime,
+ sma->sem_ctime);
+
+ complexmode_tryleave(sma);
+
+ return 0;
+}
+#endif
diff --git a/ipc/shm.c b/ipc/shm.c
new file mode 100644
index 0000000..1c65fb3
--- /dev/null
+++ b/ipc/shm.c
@@ -0,0 +1,1753 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/ipc/shm.c
+ * Copyright (C) 1992, 1993 Krishna Balasubramanian
+ * Many improvements/fixes by Bruno Haible.
+ * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994.
+ * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli.
+ *
+ * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
+ * BIGMEM support, Andrea Arcangeli <andrea@suse.de>
+ * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
+ * HIGHMEM support, Ingo Molnar <mingo@redhat.com>
+ * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com>
+ * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com>
+ * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com>
+ *
+ * support for audit of ipc object properties and permission changes
+ * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ *
+ * namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ *
+ * Better ipc lock (kern_ipc_perm.lock) handling
+ * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013.
+ */
+
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/shm.h>
+#include <linux/init.h>
+#include <linux/file.h>
+#include <linux/mman.h>
+#include <linux/shmem_fs.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <linux/capability.h>
+#include <linux/ptrace.h>
+#include <linux/seq_file.h>
+#include <linux/rwsem.h>
+#include <linux/nsproxy.h>
+#include <linux/mount.h>
+#include <linux/ipc_namespace.h>
+#include <linux/rhashtable.h>
+
+#include <linux/uaccess.h>
+
+#include "util.h"
+
+struct shmid_kernel /* private to the kernel */
+{
+ struct kern_ipc_perm shm_perm;
+ struct file *shm_file;
+ unsigned long shm_nattch;
+ unsigned long shm_segsz;
+ time64_t shm_atim;
+ time64_t shm_dtim;
+ time64_t shm_ctim;
+ struct pid *shm_cprid;
+ struct pid *shm_lprid;
+ struct user_struct *mlock_user;
+
+ /* The task created the shm object. NULL if the task is dead. */
+ struct task_struct *shm_creator;
+ struct list_head shm_clist; /* list by creator */
+} __randomize_layout;
+
+/* shm_mode upper byte flags */
+#define SHM_DEST 01000 /* segment will be destroyed on last detach */
+#define SHM_LOCKED 02000 /* segment will not be swapped */
+
+struct shm_file_data {
+ int id;
+ struct ipc_namespace *ns;
+ struct file *file;
+ const struct vm_operations_struct *vm_ops;
+};
+
+#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
+
+static const struct file_operations shm_file_operations;
+static const struct vm_operations_struct shm_vm_ops;
+
+#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
+
+#define shm_unlock(shp) \
+ ipc_unlock(&(shp)->shm_perm)
+
+static int newseg(struct ipc_namespace *, struct ipc_params *);
+static void shm_open(struct vm_area_struct *vma);
+static void shm_close(struct vm_area_struct *vma);
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
+#ifdef CONFIG_PROC_FS
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
+#endif
+
+void shm_init_ns(struct ipc_namespace *ns)
+{
+ ns->shm_ctlmax = SHMMAX;
+ ns->shm_ctlall = SHMALL;
+ ns->shm_ctlmni = SHMMNI;
+ ns->shm_rmid_forced = 0;
+ ns->shm_tot = 0;
+ ipc_init_ids(&shm_ids(ns));
+}
+
+/*
+ * Called with shm_ids.rwsem (writer) and the shp structure locked.
+ * Only shm_ids.rwsem remains locked on exit.
+ */
+static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
+{
+ struct shmid_kernel *shp;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+ if (shp->shm_nattch) {
+ shp->shm_perm.mode |= SHM_DEST;
+ /* Do not find it any more */
+ ipc_set_key_private(&shm_ids(ns), &shp->shm_perm);
+ shm_unlock(shp);
+ } else
+ shm_destroy(ns, shp);
+}
+
+#ifdef CONFIG_IPC_NS
+void shm_exit_ns(struct ipc_namespace *ns)
+{
+ free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
+ idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
+ rhashtable_destroy(&ns->ids[IPC_SHM_IDS].key_ht);
+}
+#endif
+
+static int __init ipc_ns_init(void)
+{
+ shm_init_ns(&init_ipc_ns);
+ return 0;
+}
+
+pure_initcall(ipc_ns_init);
+
+void __init shm_init(void)
+{
+ ipc_init_proc_interface("sysvipc/shm",
+#if BITS_PER_LONG <= 32
+ " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
+#else
+ " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
+#endif
+ IPC_SHM_IDS, sysvipc_shm_proc_show);
+}
+
+static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+/*
+ * shm_lock_(check_) routines are called in the paths where the rwsem
+ * is not necessarily held.
+ */
+static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp;
+
+ rcu_read_lock();
+ ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
+ if (IS_ERR(ipcp))
+ goto err;
+
+ ipc_lock_object(ipcp);
+ /*
+ * ipc_rmid() may have already freed the ID while ipc_lock_object()
+ * was spinning: here verify that the structure is still valid.
+ * Upon races with RMID, return -EIDRM, thus indicating that
+ * the ID points to a removed identifier.
+ */
+ if (ipc_valid_object(ipcp)) {
+ /* return a locked ipc object upon success */
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+ }
+
+ ipc_unlock_object(ipcp);
+ ipcp = ERR_PTR(-EIDRM);
+err:
+ rcu_read_unlock();
+ /*
+ * Callers of shm_lock() must validate the status of the returned ipc
+ * object pointer and error out as appropriate.
+ */
+ return ERR_CAST(ipcp);
+}
+
+static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
+{
+ rcu_read_lock();
+ ipc_lock_object(&ipcp->shm_perm);
+}
+
+static void shm_rcu_free(struct rcu_head *head)
+{
+ struct kern_ipc_perm *ptr = container_of(head, struct kern_ipc_perm,
+ rcu);
+ struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel,
+ shm_perm);
+ security_shm_free(&shp->shm_perm);
+ kvfree(shp);
+}
+
+static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
+{
+ list_del(&s->shm_clist);
+ ipc_rmid(&shm_ids(ns), &s->shm_perm);
+}
+
+
+static int __shm_open(struct vm_area_struct *vma)
+{
+ struct file *file = vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+ struct shmid_kernel *shp;
+
+ shp = shm_lock(sfd->ns, sfd->id);
+
+ if (IS_ERR(shp))
+ return PTR_ERR(shp);
+
+ if (shp->shm_file != sfd->file) {
+ /* ID was reused */
+ shm_unlock(shp);
+ return -EINVAL;
+ }
+
+ shp->shm_atim = ktime_get_real_seconds();
+ ipc_update_pid(&shp->shm_lprid, task_tgid(current));
+ shp->shm_nattch++;
+ shm_unlock(shp);
+ return 0;
+}
+
+/* This is called by fork, once for every shm attach. */
+static void shm_open(struct vm_area_struct *vma)
+{
+ int err = __shm_open(vma);
+ /*
+ * We raced in the idr lookup or with shm_destroy().
+ * Either way, the ID is busted.
+ */
+ WARN_ON_ONCE(err);
+}
+
+/*
+ * shm_destroy - free the struct shmid_kernel
+ *
+ * @ns: namespace
+ * @shp: struct to free
+ *
+ * It has to be called with shp and shm_ids.rwsem (writer) locked,
+ * but returns with shp unlocked and freed.
+ */
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+ struct file *shm_file;
+
+ shm_file = shp->shm_file;
+ shp->shm_file = NULL;
+ ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ shm_rmid(ns, shp);
+ shm_unlock(shp);
+ if (!is_file_hugepages(shm_file))
+ shmem_lock(shm_file, 0, shp->mlock_user);
+ else if (shp->mlock_user)
+ user_shm_unlock(i_size_read(file_inode(shm_file)),
+ shp->mlock_user);
+ fput(shm_file);
+ ipc_update_pid(&shp->shm_cprid, NULL);
+ ipc_update_pid(&shp->shm_lprid, NULL);
+ ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
+}
+
+/*
+ * shm_may_destroy - identifies whether shm segment should be destroyed now
+ *
+ * Returns true if and only if there are no active users of the segment and
+ * one of the following is true:
+ *
+ * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
+ *
+ * 2) sysctl kernel.shm_rmid_forced is set to 1.
+ */
+static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+ return (shp->shm_nattch == 0) &&
+ (ns->shm_rmid_forced ||
+ (shp->shm_perm.mode & SHM_DEST));
+}
+
+/*
+ * remove the attach descriptor vma.
+ * free memory for segment if it is marked destroyed.
+ * The descriptor has already been removed from the current->mm->mmap list
+ * and will later be kfree()d.
+ */
+static void shm_close(struct vm_area_struct *vma)
+{
+ struct file *file = vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+ struct shmid_kernel *shp;
+ struct ipc_namespace *ns = sfd->ns;
+
+ down_write(&shm_ids(ns).rwsem);
+ /* remove from the list of attaches of the shm segment */
+ shp = shm_lock(ns, sfd->id);
+
+ /*
+ * We raced in the idr lookup or with shm_destroy().
+ * Either way, the ID is busted.
+ */
+ if (WARN_ON_ONCE(IS_ERR(shp)))
+ goto done; /* no-op */
+
+ ipc_update_pid(&shp->shm_lprid, task_tgid(current));
+ shp->shm_dtim = ktime_get_real_seconds();
+ shp->shm_nattch--;
+ if (shm_may_destroy(ns, shp))
+ shm_destroy(ns, shp);
+ else
+ shm_unlock(shp);
+done:
+ up_write(&shm_ids(ns).rwsem);
+}
+
+/* Called with ns->shm_ids(ns).rwsem locked */
+static int shm_try_destroy_orphaned(int id, void *p, void *data)
+{
+ struct ipc_namespace *ns = data;
+ struct kern_ipc_perm *ipcp = p;
+ struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+ /*
+ * We want to destroy segments without users and with already
+ * exit'ed originating process.
+ *
+ * As shp->* are changed under rwsem, it's safe to skip shp locking.
+ */
+ if (shp->shm_creator != NULL)
+ return 0;
+
+ if (shm_may_destroy(ns, shp)) {
+ shm_lock_by_ptr(shp);
+ shm_destroy(ns, shp);
+ }
+ return 0;
+}
+
+void shm_destroy_orphaned(struct ipc_namespace *ns)
+{
+ down_write(&shm_ids(ns).rwsem);
+ if (shm_ids(ns).in_use)
+ idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
+ up_write(&shm_ids(ns).rwsem);
+}
+
+/* Locking assumes this will only be called with task == current */
+void exit_shm(struct task_struct *task)
+{
+ struct ipc_namespace *ns = task->nsproxy->ipc_ns;
+ struct shmid_kernel *shp, *n;
+
+ if (list_empty(&task->sysvshm.shm_clist))
+ return;
+
+ /*
+ * If kernel.shm_rmid_forced is not set then only keep track of
+ * which shmids are orphaned, so that a later set of the sysctl
+ * can clean them up.
+ */
+ if (!ns->shm_rmid_forced) {
+ down_read(&shm_ids(ns).rwsem);
+ list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
+ shp->shm_creator = NULL;
+ /*
+ * Only under read lock but we are only called on current
+ * so no entry on the list will be shared.
+ */
+ list_del(&task->sysvshm.shm_clist);
+ up_read(&shm_ids(ns).rwsem);
+ return;
+ }
+
+ /*
+ * Destroy all already created segments, that were not yet mapped,
+ * and mark any mapped as orphan to cover the sysctl toggling.
+ * Destroy is skipped if shm_may_destroy() returns false.
+ */
+ down_write(&shm_ids(ns).rwsem);
+ list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
+ shp->shm_creator = NULL;
+
+ if (shm_may_destroy(ns, shp)) {
+ shm_lock_by_ptr(shp);
+ shm_destroy(ns, shp);
+ }
+ }
+
+ /* Remove the list head from any segments still attached. */
+ list_del(&task->sysvshm.shm_clist);
+ up_write(&shm_ids(ns).rwsem);
+}
+
+static vm_fault_t shm_fault(struct vm_fault *vmf)
+{
+ struct file *file = vmf->vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ return sfd->vm_ops->fault(vmf);
+}
+
+static int shm_split(struct vm_area_struct *vma, unsigned long addr)
+{
+ struct file *file = vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ if (sfd->vm_ops->split)
+ return sfd->vm_ops->split(vma, addr);
+
+ return 0;
+}
+
+static unsigned long shm_pagesize(struct vm_area_struct *vma)
+{
+ struct file *file = vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ if (sfd->vm_ops->pagesize)
+ return sfd->vm_ops->pagesize(vma);
+
+ return PAGE_SIZE;
+}
+
+#ifdef CONFIG_NUMA
+static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
+{
+ struct file *file = vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+ int err = 0;
+
+ if (sfd->vm_ops->set_policy)
+ err = sfd->vm_ops->set_policy(vma, new);
+ return err;
+}
+
+static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct file *file = vma->vm_file;
+ struct shm_file_data *sfd = shm_file_data(file);
+ struct mempolicy *pol = NULL;
+
+ if (sfd->vm_ops->get_policy)
+ pol = sfd->vm_ops->get_policy(vma, addr);
+ else if (vma->vm_policy)
+ pol = vma->vm_policy;
+
+ return pol;
+}
+#endif
+
+static int shm_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct shm_file_data *sfd = shm_file_data(file);
+ int ret;
+
+ /*
+ * In case of remap_file_pages() emulation, the file can represent an
+ * IPC ID that was removed, and possibly even reused by another shm
+ * segment already. Propagate this case as an error to caller.
+ */
+ ret = __shm_open(vma);
+ if (ret)
+ return ret;
+
+ ret = call_mmap(sfd->file, vma);
+ if (ret) {
+ shm_close(vma);
+ return ret;
+ }
+ sfd->vm_ops = vma->vm_ops;
+#ifdef CONFIG_MMU
+ WARN_ON(!sfd->vm_ops->fault);
+#endif
+ vma->vm_ops = &shm_vm_ops;
+ return 0;
+}
+
+static int shm_release(struct inode *ino, struct file *file)
+{
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ put_ipc_ns(sfd->ns);
+ fput(sfd->file);
+ shm_file_data(file) = NULL;
+ kfree(sfd);
+ return 0;
+}
+
+static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ if (!sfd->file->f_op->fsync)
+ return -EINVAL;
+ return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
+}
+
+static long shm_fallocate(struct file *file, int mode, loff_t offset,
+ loff_t len)
+{
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ if (!sfd->file->f_op->fallocate)
+ return -EOPNOTSUPP;
+ return sfd->file->f_op->fallocate(file, mode, offset, len);
+}
+
+static unsigned long shm_get_unmapped_area(struct file *file,
+ unsigned long addr, unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
+ pgoff, flags);
+}
+
+static const struct file_operations shm_file_operations = {
+ .mmap = shm_mmap,
+ .fsync = shm_fsync,
+ .release = shm_release,
+ .get_unmapped_area = shm_get_unmapped_area,
+ .llseek = noop_llseek,
+ .fallocate = shm_fallocate,
+};
+
+/*
+ * shm_file_operations_huge is now identical to shm_file_operations,
+ * but we keep it distinct for the sake of is_file_shm_hugepages().
+ */
+static const struct file_operations shm_file_operations_huge = {
+ .mmap = shm_mmap,
+ .fsync = shm_fsync,
+ .release = shm_release,
+ .get_unmapped_area = shm_get_unmapped_area,
+ .llseek = noop_llseek,
+ .fallocate = shm_fallocate,
+};
+
+bool is_file_shm_hugepages(struct file *file)
+{
+ return file->f_op == &shm_file_operations_huge;
+}
+
+static const struct vm_operations_struct shm_vm_ops = {
+ .open = shm_open, /* callback for a new vm-area open */
+ .close = shm_close, /* callback for when the vm-area is released */
+ .fault = shm_fault,
+ .split = shm_split,
+ .pagesize = shm_pagesize,
+#if defined(CONFIG_NUMA)
+ .set_policy = shm_set_policy,
+ .get_policy = shm_get_policy,
+#endif
+};
+
+/**
+ * newseg - Create a new shared memory segment
+ * @ns: namespace
+ * @params: ptr to the structure that contains key, size and shmflg
+ *
+ * Called with shm_ids.rwsem held as a writer.
+ */
+static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
+{
+ key_t key = params->key;
+ int shmflg = params->flg;
+ size_t size = params->u.size;
+ int error;
+ struct shmid_kernel *shp;
+ size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ struct file *file;
+ char name[13];
+ vm_flags_t acctflag = 0;
+
+ if (size < SHMMIN || size > ns->shm_ctlmax)
+ return -EINVAL;
+
+ if (numpages << PAGE_SHIFT < size)
+ return -ENOSPC;
+
+ if (ns->shm_tot + numpages < ns->shm_tot ||
+ ns->shm_tot + numpages > ns->shm_ctlall)
+ return -ENOSPC;
+
+ shp = kvmalloc(sizeof(*shp), GFP_KERNEL);
+ if (unlikely(!shp))
+ return -ENOMEM;
+
+ shp->shm_perm.key = key;
+ shp->shm_perm.mode = (shmflg & S_IRWXUGO);
+ shp->mlock_user = NULL;
+
+ shp->shm_perm.security = NULL;
+ error = security_shm_alloc(&shp->shm_perm);
+ if (error) {
+ kvfree(shp);
+ return error;
+ }
+
+ sprintf(name, "SYSV%08x", key);
+ if (shmflg & SHM_HUGETLB) {
+ struct hstate *hs;
+ size_t hugesize;
+
+ hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
+ if (!hs) {
+ error = -EINVAL;
+ goto no_file;
+ }
+ hugesize = ALIGN(size, huge_page_size(hs));
+
+ /* hugetlb_file_setup applies strict accounting */
+ if (shmflg & SHM_NORESERVE)
+ acctflag = VM_NORESERVE;
+ file = hugetlb_file_setup(name, hugesize, acctflag,
+ &shp->mlock_user, HUGETLB_SHMFS_INODE,
+ (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
+ } else {
+ /*
+ * Do not allow no accounting for OVERCOMMIT_NEVER, even
+ * if it's asked for.
+ */
+ if ((shmflg & SHM_NORESERVE) &&
+ sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+ acctflag = VM_NORESERVE;
+ file = shmem_kernel_file_setup(name, size, acctflag);
+ }
+ error = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto no_file;
+
+ shp->shm_cprid = get_pid(task_tgid(current));
+ shp->shm_lprid = NULL;
+ shp->shm_atim = shp->shm_dtim = 0;
+ shp->shm_ctim = ktime_get_real_seconds();
+ shp->shm_segsz = size;
+ shp->shm_nattch = 0;
+ shp->shm_file = file;
+ shp->shm_creator = current;
+
+ /* ipc_addid() locks shp upon success. */
+ error = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
+ if (error < 0)
+ goto no_id;
+
+ list_add(&shp->shm_clist, ¤t->sysvshm.shm_clist);
+
+ /*
+ * shmid gets reported as "inode#" in /proc/pid/maps.
+ * proc-ps tools use this. Changing this will break them.
+ */
+ file_inode(file)->i_ino = shp->shm_perm.id;
+
+ ns->shm_tot += numpages;
+ error = shp->shm_perm.id;
+
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
+ return error;
+
+no_id:
+ ipc_update_pid(&shp->shm_cprid, NULL);
+ ipc_update_pid(&shp->shm_lprid, NULL);
+ if (is_file_hugepages(file) && shp->mlock_user)
+ user_shm_unlock(size, shp->mlock_user);
+ fput(file);
+ ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
+ return error;
+no_file:
+ call_rcu(&shp->shm_perm.rcu, shm_rcu_free);
+ return error;
+}
+
+/*
+ * Called with shm_ids.rwsem and ipcp locked.
+ */
+static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
+ struct ipc_params *params)
+{
+ struct shmid_kernel *shp;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ if (shp->shm_segsz < params->u.size)
+ return -EINVAL;
+
+ return 0;
+}
+
+long ksys_shmget(key_t key, size_t size, int shmflg)
+{
+ struct ipc_namespace *ns;
+ static const struct ipc_ops shm_ops = {
+ .getnew = newseg,
+ .associate = security_shm_associate,
+ .more_checks = shm_more_checks,
+ };
+ struct ipc_params shm_params;
+
+ ns = current->nsproxy->ipc_ns;
+
+ shm_params.key = key;
+ shm_params.flg = shmflg;
+ shm_params.u.size = size;
+
+ return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
+}
+
+SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
+{
+ return ksys_shmget(key, size, shmflg);
+}
+
+static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
+{
+ switch (version) {
+ case IPC_64:
+ return copy_to_user(buf, in, sizeof(*in));
+ case IPC_OLD:
+ {
+ struct shmid_ds out;
+
+ memset(&out, 0, sizeof(out));
+ ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
+ out.shm_segsz = in->shm_segsz;
+ out.shm_atime = in->shm_atime;
+ out.shm_dtime = in->shm_dtime;
+ out.shm_ctime = in->shm_ctime;
+ out.shm_cpid = in->shm_cpid;
+ out.shm_lpid = in->shm_lpid;
+ out.shm_nattch = in->shm_nattch;
+
+ return copy_to_user(buf, &out, sizeof(out));
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
+{
+ switch (version) {
+ case IPC_64:
+ if (copy_from_user(out, buf, sizeof(*out)))
+ return -EFAULT;
+ return 0;
+ case IPC_OLD:
+ {
+ struct shmid_ds tbuf_old;
+
+ if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+ return -EFAULT;
+
+ out->shm_perm.uid = tbuf_old.shm_perm.uid;
+ out->shm_perm.gid = tbuf_old.shm_perm.gid;
+ out->shm_perm.mode = tbuf_old.shm_perm.mode;
+
+ return 0;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
+{
+ switch (version) {
+ case IPC_64:
+ return copy_to_user(buf, in, sizeof(*in));
+ case IPC_OLD:
+ {
+ struct shminfo out;
+
+ if (in->shmmax > INT_MAX)
+ out.shmmax = INT_MAX;
+ else
+ out.shmmax = (int)in->shmmax;
+
+ out.shmmin = in->shmmin;
+ out.shmmni = in->shmmni;
+ out.shmseg = in->shmseg;
+ out.shmall = in->shmall;
+
+ return copy_to_user(buf, &out, sizeof(out));
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * Calculate and add used RSS and swap pages of a shm.
+ * Called with shm_ids.rwsem held as a reader
+ */
+static void shm_add_rss_swap(struct shmid_kernel *shp,
+ unsigned long *rss_add, unsigned long *swp_add)
+{
+ struct inode *inode;
+
+ inode = file_inode(shp->shm_file);
+
+ if (is_file_hugepages(shp->shm_file)) {
+ struct address_space *mapping = inode->i_mapping;
+ struct hstate *h = hstate_file(shp->shm_file);
+ *rss_add += pages_per_huge_page(h) * mapping->nrpages;
+ } else {
+#ifdef CONFIG_SHMEM
+ struct shmem_inode_info *info = SHMEM_I(inode);
+
+ spin_lock_irq(&info->lock);
+ *rss_add += inode->i_mapping->nrpages;
+ *swp_add += info->swapped;
+ spin_unlock_irq(&info->lock);
+#else
+ *rss_add += inode->i_mapping->nrpages;
+#endif
+ }
+}
+
+/*
+ * Called with shm_ids.rwsem held as a reader
+ */
+static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
+ unsigned long *swp)
+{
+ int next_id;
+ int total, in_use;
+
+ *rss = 0;
+ *swp = 0;
+
+ in_use = shm_ids(ns).in_use;
+
+ for (total = 0, next_id = 0; total < in_use; next_id++) {
+ struct kern_ipc_perm *ipc;
+ struct shmid_kernel *shp;
+
+ ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+ if (ipc == NULL)
+ continue;
+ shp = container_of(ipc, struct shmid_kernel, shm_perm);
+
+ shm_add_rss_swap(shp, rss, swp);
+
+ total++;
+ }
+}
+
+/*
+ * This function handles some shmctl commands which require the rwsem
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
+ */
+static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
+ struct shmid64_ds *shmid64)
+{
+ struct kern_ipc_perm *ipcp;
+ struct shmid_kernel *shp;
+ int err;
+
+ down_write(&shm_ids(ns).rwsem);
+ rcu_read_lock();
+
+ ipcp = ipcctl_obtain_check(ns, &shm_ids(ns), shmid, cmd,
+ &shmid64->shm_perm, 0);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto out_unlock1;
+ }
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+ err = security_shm_shmctl(&shp->shm_perm, cmd);
+ if (err)
+ goto out_unlock1;
+
+ switch (cmd) {
+ case IPC_RMID:
+ ipc_lock_object(&shp->shm_perm);
+ /* do_shm_rmid unlocks the ipc object and rcu */
+ do_shm_rmid(ns, ipcp);
+ goto out_up;
+ case IPC_SET:
+ ipc_lock_object(&shp->shm_perm);
+ err = ipc_update_perm(&shmid64->shm_perm, ipcp);
+ if (err)
+ goto out_unlock0;
+ shp->shm_ctim = ktime_get_real_seconds();
+ break;
+ default:
+ err = -EINVAL;
+ goto out_unlock1;
+ }
+
+out_unlock0:
+ ipc_unlock_object(&shp->shm_perm);
+out_unlock1:
+ rcu_read_unlock();
+out_up:
+ up_write(&shm_ids(ns).rwsem);
+ return err;
+}
+
+static int shmctl_ipc_info(struct ipc_namespace *ns,
+ struct shminfo64 *shminfo)
+{
+ int err = security_shm_shmctl(NULL, IPC_INFO);
+ if (!err) {
+ memset(shminfo, 0, sizeof(*shminfo));
+ shminfo->shmmni = shminfo->shmseg = ns->shm_ctlmni;
+ shminfo->shmmax = ns->shm_ctlmax;
+ shminfo->shmall = ns->shm_ctlall;
+ shminfo->shmmin = SHMMIN;
+ down_read(&shm_ids(ns).rwsem);
+ err = ipc_get_maxidx(&shm_ids(ns));
+ up_read(&shm_ids(ns).rwsem);
+ if (err < 0)
+ err = 0;
+ }
+ return err;
+}
+
+static int shmctl_shm_info(struct ipc_namespace *ns,
+ struct shm_info *shm_info)
+{
+ int err = security_shm_shmctl(NULL, SHM_INFO);
+ if (!err) {
+ memset(shm_info, 0, sizeof(*shm_info));
+ down_read(&shm_ids(ns).rwsem);
+ shm_info->used_ids = shm_ids(ns).in_use;
+ shm_get_stat(ns, &shm_info->shm_rss, &shm_info->shm_swp);
+ shm_info->shm_tot = ns->shm_tot;
+ shm_info->swap_attempts = 0;
+ shm_info->swap_successes = 0;
+ err = ipc_get_maxidx(&shm_ids(ns));
+ up_read(&shm_ids(ns).rwsem);
+ if (err < 0)
+ err = 0;
+ }
+ return err;
+}
+
+static int shmctl_stat(struct ipc_namespace *ns, int shmid,
+ int cmd, struct shmid64_ds *tbuf)
+{
+ struct shmid_kernel *shp;
+ int err;
+
+ memset(tbuf, 0, sizeof(*tbuf));
+
+ rcu_read_lock();
+ if (cmd == SHM_STAT || cmd == SHM_STAT_ANY) {
+ shp = shm_obtain_object(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out_unlock;
+ }
+ } else { /* IPC_STAT */
+ shp = shm_obtain_object_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out_unlock;
+ }
+ }
+
+ /*
+ * Semantically SHM_STAT_ANY ought to be identical to
+ * that functionality provided by the /proc/sysvipc/
+ * interface. As such, only audit these calls and
+ * do not do traditional S_IRUGO permission checks on
+ * the ipc object.
+ */
+ if (cmd == SHM_STAT_ANY)
+ audit_ipc_obj(&shp->shm_perm);
+ else {
+ err = -EACCES;
+ if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
+ goto out_unlock;
+ }
+
+ err = security_shm_shmctl(&shp->shm_perm, cmd);
+ if (err)
+ goto out_unlock;
+
+ ipc_lock_object(&shp->shm_perm);
+
+ if (!ipc_valid_object(&shp->shm_perm)) {
+ ipc_unlock_object(&shp->shm_perm);
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ kernel_to_ipc64_perm(&shp->shm_perm, &tbuf->shm_perm);
+ tbuf->shm_segsz = shp->shm_segsz;
+ tbuf->shm_atime = shp->shm_atim;
+ tbuf->shm_dtime = shp->shm_dtim;
+ tbuf->shm_ctime = shp->shm_ctim;
+#ifndef CONFIG_64BIT
+ tbuf->shm_atime_high = shp->shm_atim >> 32;
+ tbuf->shm_dtime_high = shp->shm_dtim >> 32;
+ tbuf->shm_ctime_high = shp->shm_ctim >> 32;
+#endif
+ tbuf->shm_cpid = pid_vnr(shp->shm_cprid);
+ tbuf->shm_lpid = pid_vnr(shp->shm_lprid);
+ tbuf->shm_nattch = shp->shm_nattch;
+
+ if (cmd == IPC_STAT) {
+ /*
+ * As defined in SUS:
+ * Return 0 on success
+ */
+ err = 0;
+ } else {
+ /*
+ * SHM_STAT and SHM_STAT_ANY (both Linux specific)
+ * Return the full id, including the sequence number
+ */
+ err = shp->shm_perm.id;
+ }
+
+ ipc_unlock_object(&shp->shm_perm);
+out_unlock:
+ rcu_read_unlock();
+ return err;
+}
+
+static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd)
+{
+ struct shmid_kernel *shp;
+ struct file *shm_file;
+ int err;
+
+ rcu_read_lock();
+ shp = shm_obtain_object_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out_unlock1;
+ }
+
+ audit_ipc_obj(&(shp->shm_perm));
+ err = security_shm_shmctl(&shp->shm_perm, cmd);
+ if (err)
+ goto out_unlock1;
+
+ ipc_lock_object(&shp->shm_perm);
+
+ /* check if shm_destroy() is tearing down shp */
+ if (!ipc_valid_object(&shp->shm_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
+
+ if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
+ kuid_t euid = current_euid();
+
+ if (!uid_eq(euid, shp->shm_perm.uid) &&
+ !uid_eq(euid, shp->shm_perm.cuid)) {
+ err = -EPERM;
+ goto out_unlock0;
+ }
+ if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
+ err = -EPERM;
+ goto out_unlock0;
+ }
+ }
+
+ shm_file = shp->shm_file;
+ if (is_file_hugepages(shm_file))
+ goto out_unlock0;
+
+ if (cmd == SHM_LOCK) {
+ struct user_struct *user = current_user();
+
+ err = shmem_lock(shm_file, 1, user);
+ if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
+ shp->shm_perm.mode |= SHM_LOCKED;
+ shp->mlock_user = user;
+ }
+ goto out_unlock0;
+ }
+
+ /* SHM_UNLOCK */
+ if (!(shp->shm_perm.mode & SHM_LOCKED))
+ goto out_unlock0;
+ shmem_lock(shm_file, 0, shp->mlock_user);
+ shp->shm_perm.mode &= ~SHM_LOCKED;
+ shp->mlock_user = NULL;
+ get_file(shm_file);
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
+ shmem_unlock_mapping(shm_file->f_mapping);
+
+ fput(shm_file);
+ return err;
+
+out_unlock0:
+ ipc_unlock_object(&shp->shm_perm);
+out_unlock1:
+ rcu_read_unlock();
+ return err;
+}
+
+long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
+{
+ int err, version;
+ struct ipc_namespace *ns;
+ struct shmid64_ds sem64;
+
+ if (cmd < 0 || shmid < 0)
+ return -EINVAL;
+
+ version = ipc_parse_version(&cmd);
+ ns = current->nsproxy->ipc_ns;
+
+ switch (cmd) {
+ case IPC_INFO: {
+ struct shminfo64 shminfo;
+ err = shmctl_ipc_info(ns, &shminfo);
+ if (err < 0)
+ return err;
+ if (copy_shminfo_to_user(buf, &shminfo, version))
+ err = -EFAULT;
+ return err;
+ }
+ case SHM_INFO: {
+ struct shm_info shm_info;
+ err = shmctl_shm_info(ns, &shm_info);
+ if (err < 0)
+ return err;
+ if (copy_to_user(buf, &shm_info, sizeof(shm_info)))
+ err = -EFAULT;
+ return err;
+ }
+ case SHM_STAT:
+ case SHM_STAT_ANY:
+ case IPC_STAT: {
+ err = shmctl_stat(ns, shmid, cmd, &sem64);
+ if (err < 0)
+ return err;
+ if (copy_shmid_to_user(buf, &sem64, version))
+ err = -EFAULT;
+ return err;
+ }
+ case IPC_SET:
+ if (copy_shmid_from_user(&sem64, buf, version))
+ return -EFAULT;
+ /* fallthru */
+ case IPC_RMID:
+ return shmctl_down(ns, shmid, cmd, &sem64);
+ case SHM_LOCK:
+ case SHM_UNLOCK:
+ return shmctl_do_lock(ns, shmid, cmd);
+ default:
+ return -EINVAL;
+ }
+}
+
+SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
+{
+ return ksys_shmctl(shmid, cmd, buf);
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_shmid_ds {
+ struct compat_ipc_perm shm_perm;
+ int shm_segsz;
+ compat_time_t shm_atime;
+ compat_time_t shm_dtime;
+ compat_time_t shm_ctime;
+ compat_ipc_pid_t shm_cpid;
+ compat_ipc_pid_t shm_lpid;
+ unsigned short shm_nattch;
+ unsigned short shm_unused;
+ compat_uptr_t shm_unused2;
+ compat_uptr_t shm_unused3;
+};
+
+struct compat_shminfo64 {
+ compat_ulong_t shmmax;
+ compat_ulong_t shmmin;
+ compat_ulong_t shmmni;
+ compat_ulong_t shmseg;
+ compat_ulong_t shmall;
+ compat_ulong_t __unused1;
+ compat_ulong_t __unused2;
+ compat_ulong_t __unused3;
+ compat_ulong_t __unused4;
+};
+
+struct compat_shm_info {
+ compat_int_t used_ids;
+ compat_ulong_t shm_tot, shm_rss, shm_swp;
+ compat_ulong_t swap_attempts, swap_successes;
+};
+
+static int copy_compat_shminfo_to_user(void __user *buf, struct shminfo64 *in,
+ int version)
+{
+ if (in->shmmax > INT_MAX)
+ in->shmmax = INT_MAX;
+ if (version == IPC_64) {
+ struct compat_shminfo64 info;
+ memset(&info, 0, sizeof(info));
+ info.shmmax = in->shmmax;
+ info.shmmin = in->shmmin;
+ info.shmmni = in->shmmni;
+ info.shmseg = in->shmseg;
+ info.shmall = in->shmall;
+ return copy_to_user(buf, &info, sizeof(info));
+ } else {
+ struct shminfo info;
+ memset(&info, 0, sizeof(info));
+ info.shmmax = in->shmmax;
+ info.shmmin = in->shmmin;
+ info.shmmni = in->shmmni;
+ info.shmseg = in->shmseg;
+ info.shmall = in->shmall;
+ return copy_to_user(buf, &info, sizeof(info));
+ }
+}
+
+static int put_compat_shm_info(struct shm_info *ip,
+ struct compat_shm_info __user *uip)
+{
+ struct compat_shm_info info;
+
+ memset(&info, 0, sizeof(info));
+ info.used_ids = ip->used_ids;
+ info.shm_tot = ip->shm_tot;
+ info.shm_rss = ip->shm_rss;
+ info.shm_swp = ip->shm_swp;
+ info.swap_attempts = ip->swap_attempts;
+ info.swap_successes = ip->swap_successes;
+ return copy_to_user(uip, &info, sizeof(info));
+}
+
+static int copy_compat_shmid_to_user(void __user *buf, struct shmid64_ds *in,
+ int version)
+{
+ if (version == IPC_64) {
+ struct compat_shmid64_ds v;
+ memset(&v, 0, sizeof(v));
+ to_compat_ipc64_perm(&v.shm_perm, &in->shm_perm);
+ v.shm_atime = lower_32_bits(in->shm_atime);
+ v.shm_atime_high = upper_32_bits(in->shm_atime);
+ v.shm_dtime = lower_32_bits(in->shm_dtime);
+ v.shm_dtime_high = upper_32_bits(in->shm_dtime);
+ v.shm_ctime = lower_32_bits(in->shm_ctime);
+ v.shm_ctime_high = upper_32_bits(in->shm_ctime);
+ v.shm_segsz = in->shm_segsz;
+ v.shm_nattch = in->shm_nattch;
+ v.shm_cpid = in->shm_cpid;
+ v.shm_lpid = in->shm_lpid;
+ return copy_to_user(buf, &v, sizeof(v));
+ } else {
+ struct compat_shmid_ds v;
+ memset(&v, 0, sizeof(v));
+ to_compat_ipc_perm(&v.shm_perm, &in->shm_perm);
+ v.shm_perm.key = in->shm_perm.key;
+ v.shm_atime = in->shm_atime;
+ v.shm_dtime = in->shm_dtime;
+ v.shm_ctime = in->shm_ctime;
+ v.shm_segsz = in->shm_segsz;
+ v.shm_nattch = in->shm_nattch;
+ v.shm_cpid = in->shm_cpid;
+ v.shm_lpid = in->shm_lpid;
+ return copy_to_user(buf, &v, sizeof(v));
+ }
+}
+
+static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf,
+ int version)
+{
+ memset(out, 0, sizeof(*out));
+ if (version == IPC_64) {
+ struct compat_shmid64_ds __user *p = buf;
+ return get_compat_ipc64_perm(&out->shm_perm, &p->shm_perm);
+ } else {
+ struct compat_shmid_ds __user *p = buf;
+ return get_compat_ipc_perm(&out->shm_perm, &p->shm_perm);
+ }
+}
+
+long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr)
+{
+ struct ipc_namespace *ns;
+ struct shmid64_ds sem64;
+ int version = compat_ipc_parse_version(&cmd);
+ int err;
+
+ ns = current->nsproxy->ipc_ns;
+
+ if (cmd < 0 || shmid < 0)
+ return -EINVAL;
+
+ switch (cmd) {
+ case IPC_INFO: {
+ struct shminfo64 shminfo;
+ err = shmctl_ipc_info(ns, &shminfo);
+ if (err < 0)
+ return err;
+ if (copy_compat_shminfo_to_user(uptr, &shminfo, version))
+ err = -EFAULT;
+ return err;
+ }
+ case SHM_INFO: {
+ struct shm_info shm_info;
+ err = shmctl_shm_info(ns, &shm_info);
+ if (err < 0)
+ return err;
+ if (put_compat_shm_info(&shm_info, uptr))
+ err = -EFAULT;
+ return err;
+ }
+ case IPC_STAT:
+ case SHM_STAT_ANY:
+ case SHM_STAT:
+ err = shmctl_stat(ns, shmid, cmd, &sem64);
+ if (err < 0)
+ return err;
+ if (copy_compat_shmid_to_user(uptr, &sem64, version))
+ err = -EFAULT;
+ return err;
+
+ case IPC_SET:
+ if (copy_compat_shmid_from_user(&sem64, uptr, version))
+ return -EFAULT;
+ /* fallthru */
+ case IPC_RMID:
+ return shmctl_down(ns, shmid, cmd, &sem64);
+ case SHM_LOCK:
+ case SHM_UNLOCK:
+ return shmctl_do_lock(ns, shmid, cmd);
+ break;
+ default:
+ return -EINVAL;
+ }
+ return err;
+}
+
+COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
+{
+ return compat_ksys_shmctl(shmid, cmd, uptr);
+}
+#endif
+
+/*
+ * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
+ *
+ * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
+ * "raddr" thing points to kernel space, and there has to be a wrapper around
+ * this.
+ */
+long do_shmat(int shmid, char __user *shmaddr, int shmflg,
+ ulong *raddr, unsigned long shmlba)
+{
+ struct shmid_kernel *shp;
+ unsigned long addr = (unsigned long)shmaddr;
+ unsigned long size;
+ struct file *file, *base;
+ int err;
+ unsigned long flags = MAP_SHARED;
+ unsigned long prot;
+ int acc_mode;
+ struct ipc_namespace *ns;
+ struct shm_file_data *sfd;
+ int f_flags;
+ unsigned long populate = 0;
+
+ err = -EINVAL;
+ if (shmid < 0)
+ goto out;
+
+ if (addr) {
+ if (addr & (shmlba - 1)) {
+ if (shmflg & SHM_RND) {
+ addr &= ~(shmlba - 1); /* round down */
+
+ /*
+ * Ensure that the round-down is non-nil
+ * when remapping. This can happen for
+ * cases when addr < shmlba.
+ */
+ if (!addr && (shmflg & SHM_REMAP))
+ goto out;
+ } else
+#ifndef __ARCH_FORCE_SHMLBA
+ if (addr & ~PAGE_MASK)
+#endif
+ goto out;
+ }
+
+ flags |= MAP_FIXED;
+ } else if ((shmflg & SHM_REMAP))
+ goto out;
+
+ if (shmflg & SHM_RDONLY) {
+ prot = PROT_READ;
+ acc_mode = S_IRUGO;
+ f_flags = O_RDONLY;
+ } else {
+ prot = PROT_READ | PROT_WRITE;
+ acc_mode = S_IRUGO | S_IWUGO;
+ f_flags = O_RDWR;
+ }
+ if (shmflg & SHM_EXEC) {
+ prot |= PROT_EXEC;
+ acc_mode |= S_IXUGO;
+ }
+
+ /*
+ * We cannot rely on the fs check since SYSV IPC does have an
+ * additional creator id...
+ */
+ ns = current->nsproxy->ipc_ns;
+ rcu_read_lock();
+ shp = shm_obtain_object_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out_unlock;
+ }
+
+ err = -EACCES;
+ if (ipcperms(ns, &shp->shm_perm, acc_mode))
+ goto out_unlock;
+
+ err = security_shm_shmat(&shp->shm_perm, shmaddr, shmflg);
+ if (err)
+ goto out_unlock;
+
+ ipc_lock_object(&shp->shm_perm);
+
+ /* check if shm_destroy() is tearing down shp */
+ if (!ipc_valid_object(&shp->shm_perm)) {
+ ipc_unlock_object(&shp->shm_perm);
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ /*
+ * We need to take a reference to the real shm file to prevent the
+ * pointer from becoming stale in cases where the lifetime of the outer
+ * file extends beyond that of the shm segment. It's not usually
+ * possible, but it can happen during remap_file_pages() emulation as
+ * that unmaps the memory, then does ->mmap() via file reference only.
+ * We'll deny the ->mmap() if the shm segment was since removed, but to
+ * detect shm ID reuse we need to compare the file pointers.
+ */
+ base = get_file(shp->shm_file);
+ shp->shm_nattch++;
+ size = i_size_read(file_inode(base));
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
+
+ err = -ENOMEM;
+ sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
+ if (!sfd) {
+ fput(base);
+ goto out_nattch;
+ }
+
+ file = alloc_file_clone(base, f_flags,
+ is_file_hugepages(base) ?
+ &shm_file_operations_huge :
+ &shm_file_operations);
+ err = PTR_ERR(file);
+ if (IS_ERR(file)) {
+ kfree(sfd);
+ fput(base);
+ goto out_nattch;
+ }
+
+ sfd->id = shp->shm_perm.id;
+ sfd->ns = get_ipc_ns(ns);
+ sfd->file = base;
+ sfd->vm_ops = NULL;
+ file->private_data = sfd;
+
+ err = security_mmap_file(file, prot, flags);
+ if (err)
+ goto out_fput;
+
+ if (down_write_killable(¤t->mm->mmap_sem)) {
+ err = -EINTR;
+ goto out_fput;
+ }
+
+ if (addr && !(shmflg & SHM_REMAP)) {
+ err = -EINVAL;
+ if (addr + size < addr)
+ goto invalid;
+
+ if (find_vma_intersection(current->mm, addr, addr + size))
+ goto invalid;
+ }
+
+ addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate, NULL);
+ *raddr = addr;
+ err = 0;
+ if (IS_ERR_VALUE(addr))
+ err = (long)addr;
+invalid:
+ up_write(¤t->mm->mmap_sem);
+ if (populate)
+ mm_populate(addr, populate);
+
+out_fput:
+ fput(file);
+
+out_nattch:
+ down_write(&shm_ids(ns).rwsem);
+ shp = shm_lock(ns, shmid);
+ shp->shm_nattch--;
+ if (shm_may_destroy(ns, shp))
+ shm_destroy(ns, shp);
+ else
+ shm_unlock(shp);
+ up_write(&shm_ids(ns).rwsem);
+ return err;
+
+out_unlock:
+ rcu_read_unlock();
+out:
+ return err;
+}
+
+SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
+{
+ unsigned long ret;
+ long err;
+
+ err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
+ if (err)
+ return err;
+ force_successful_syscall_return();
+ return (long)ret;
+}
+
+#ifdef CONFIG_COMPAT
+
+#ifndef COMPAT_SHMLBA
+#define COMPAT_SHMLBA SHMLBA
+#endif
+
+COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg)
+{
+ unsigned long ret;
+ long err;
+
+ err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA);
+ if (err)
+ return err;
+ force_successful_syscall_return();
+ return (long)ret;
+}
+#endif
+
+/*
+ * detach and kill segment if marked destroyed.
+ * The work is done in shm_close.
+ */
+long ksys_shmdt(char __user *shmaddr)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long addr = (unsigned long)shmaddr;
+ int retval = -EINVAL;
+#ifdef CONFIG_MMU
+ loff_t size = 0;
+ struct file *file;
+ struct vm_area_struct *next;
+#endif
+
+ if (addr & ~PAGE_MASK)
+ return retval;
+
+ if (down_write_killable(&mm->mmap_sem))
+ return -EINTR;
+
+ /*
+ * This function tries to be smart and unmap shm segments that
+ * were modified by partial mlock or munmap calls:
+ * - It first determines the size of the shm segment that should be
+ * unmapped: It searches for a vma that is backed by shm and that
+ * started at address shmaddr. It records it's size and then unmaps
+ * it.
+ * - Then it unmaps all shm vmas that started at shmaddr and that
+ * are within the initially determined size and that are from the
+ * same shm segment from which we determined the size.
+ * Errors from do_munmap are ignored: the function only fails if
+ * it's called with invalid parameters or if it's called to unmap
+ * a part of a vma. Both calls in this function are for full vmas,
+ * the parameters are directly copied from the vma itself and always
+ * valid - therefore do_munmap cannot fail. (famous last words?)
+ */
+ /*
+ * If it had been mremap()'d, the starting address would not
+ * match the usual checks anyway. So assume all vma's are
+ * above the starting address given.
+ */
+ vma = find_vma(mm, addr);
+
+#ifdef CONFIG_MMU
+ while (vma) {
+ next = vma->vm_next;
+
+ /*
+ * Check if the starting address would match, i.e. it's
+ * a fragment created by mprotect() and/or munmap(), or it
+ * otherwise it starts at this address with no hassles.
+ */
+ if ((vma->vm_ops == &shm_vm_ops) &&
+ (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
+
+ /*
+ * Record the file of the shm segment being
+ * unmapped. With mremap(), someone could place
+ * page from another segment but with equal offsets
+ * in the range we are unmapping.
+ */
+ file = vma->vm_file;
+ size = i_size_read(file_inode(vma->vm_file));
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ /*
+ * We discovered the size of the shm segment, so
+ * break out of here and fall through to the next
+ * loop that uses the size information to stop
+ * searching for matching vma's.
+ */
+ retval = 0;
+ vma = next;
+ break;
+ }
+ vma = next;
+ }
+
+ /*
+ * We need look no further than the maximum address a fragment
+ * could possibly have landed at. Also cast things to loff_t to
+ * prevent overflows and make comparisons vs. equal-width types.
+ */
+ size = PAGE_ALIGN(size);
+ while (vma && (loff_t)(vma->vm_end - addr) <= size) {
+ next = vma->vm_next;
+
+ /* finding a matching vma now does not alter retval */
+ if ((vma->vm_ops == &shm_vm_ops) &&
+ ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
+ (vma->vm_file == file))
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ vma = next;
+ }
+
+#else /* CONFIG_MMU */
+ /* under NOMMU conditions, the exact address to be destroyed must be
+ * given
+ */
+ if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ retval = 0;
+ }
+
+#endif
+
+ up_write(&mm->mmap_sem);
+ return retval;
+}
+
+SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
+{
+ return ksys_shmdt(shmaddr);
+}
+
+#ifdef CONFIG_PROC_FS
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
+{
+ struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
+ struct user_namespace *user_ns = seq_user_ns(s);
+ struct kern_ipc_perm *ipcp = it;
+ struct shmid_kernel *shp;
+ unsigned long rss = 0, swp = 0;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ shm_add_rss_swap(shp, &rss, &swp);
+
+#if BITS_PER_LONG <= 32
+#define SIZE_SPEC "%10lu"
+#else
+#define SIZE_SPEC "%21lu"
+#endif
+
+ seq_printf(s,
+ "%10d %10d %4o " SIZE_SPEC " %5u %5u "
+ "%5lu %5u %5u %5u %5u %10llu %10llu %10llu "
+ SIZE_SPEC " " SIZE_SPEC "\n",
+ shp->shm_perm.key,
+ shp->shm_perm.id,
+ shp->shm_perm.mode,
+ shp->shm_segsz,
+ pid_nr_ns(shp->shm_cprid, pid_ns),
+ pid_nr_ns(shp->shm_lprid, pid_ns),
+ shp->shm_nattch,
+ from_kuid_munged(user_ns, shp->shm_perm.uid),
+ from_kgid_munged(user_ns, shp->shm_perm.gid),
+ from_kuid_munged(user_ns, shp->shm_perm.cuid),
+ from_kgid_munged(user_ns, shp->shm_perm.cgid),
+ shp->shm_atim,
+ shp->shm_dtim,
+ shp->shm_ctim,
+ rss * PAGE_SIZE,
+ swp * PAGE_SIZE);
+
+ return 0;
+}
+#endif
diff --git a/ipc/syscall.c b/ipc/syscall.c
new file mode 100644
index 0000000..65d405f
--- /dev/null
+++ b/ipc/syscall.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
+ *
+ * This is really horribly ugly, and new architectures should just wire up
+ * the individual syscalls instead.
+ */
+#include <linux/unistd.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/ipc_namespace.h>
+#include "util.h"
+
+#ifdef __ARCH_WANT_SYS_IPC
+#include <linux/errno.h>
+#include <linux/ipc.h>
+#include <linux/shm.h>
+#include <linux/uaccess.h>
+
+SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
+ unsigned long, third, void __user *, ptr, long, fifth)
+{
+ int version, ret;
+
+ version = call >> 16; /* hack for backward compatibility */
+ call &= 0xffff;
+
+ switch (call) {
+ case SEMOP:
+ return ksys_semtimedop(first, (struct sembuf __user *)ptr,
+ second, NULL);
+ case SEMTIMEDOP:
+ if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
+ return ksys_semtimedop(first, ptr, second,
+ (const struct __kernel_timespec __user *)fifth);
+ else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
+ return compat_ksys_semtimedop(first, ptr, second,
+ (const struct compat_timespec __user *)fifth);
+ else
+ return -ENOSYS;
+
+ case SEMGET:
+ return ksys_semget(first, second, third);
+ case SEMCTL: {
+ unsigned long arg;
+ if (!ptr)
+ return -EINVAL;
+ if (get_user(arg, (unsigned long __user *) ptr))
+ return -EFAULT;
+ return ksys_semctl(first, second, third, arg);
+ }
+
+ case MSGSND:
+ return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
+ second, third);
+ case MSGRCV:
+ switch (version) {
+ case 0: {
+ struct ipc_kludge tmp;
+ if (!ptr)
+ return -EINVAL;
+
+ if (copy_from_user(&tmp,
+ (struct ipc_kludge __user *) ptr,
+ sizeof(tmp)))
+ return -EFAULT;
+ return ksys_msgrcv(first, tmp.msgp, second,
+ tmp.msgtyp, third);
+ }
+ default:
+ return ksys_msgrcv(first,
+ (struct msgbuf __user *) ptr,
+ second, fifth, third);
+ }
+ case MSGGET:
+ return ksys_msgget((key_t) first, second);
+ case MSGCTL:
+ return ksys_msgctl(first, second,
+ (struct msqid_ds __user *)ptr);
+
+ case SHMAT:
+ switch (version) {
+ default: {
+ unsigned long raddr;
+ ret = do_shmat(first, (char __user *)ptr,
+ second, &raddr, SHMLBA);
+ if (ret)
+ return ret;
+ return put_user(raddr, (unsigned long __user *) third);
+ }
+ case 1:
+ /*
+ * This was the entry point for kernel-originating calls
+ * from iBCS2 in 2.2 days.
+ */
+ return -EINVAL;
+ }
+ case SHMDT:
+ return ksys_shmdt((char __user *)ptr);
+ case SHMGET:
+ return ksys_shmget(first, second, third);
+ case SHMCTL:
+ return ksys_shmctl(first, second,
+ (struct shmid_ds __user *) ptr);
+ default:
+ return -ENOSYS;
+ }
+}
+#endif
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+
+#ifndef COMPAT_SHMLBA
+#define COMPAT_SHMLBA SHMLBA
+#endif
+
+struct compat_ipc_kludge {
+ compat_uptr_t msgp;
+ compat_long_t msgtyp;
+};
+
+#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
+COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
+ u32, third, compat_uptr_t, ptr, u32, fifth)
+{
+ int version;
+ u32 pad;
+
+ version = call >> 16; /* hack for backward compatibility */
+ call &= 0xffff;
+
+ switch (call) {
+ case SEMOP:
+ /* struct sembuf is the same on 32 and 64bit :)) */
+ return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
+ case SEMTIMEDOP:
+ if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
+ return -ENOSYS;
+ return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
+ compat_ptr(fifth));
+ case SEMGET:
+ return ksys_semget(first, second, third);
+ case SEMCTL:
+ if (!ptr)
+ return -EINVAL;
+ if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
+ return -EFAULT;
+ return compat_ksys_semctl(first, second, third, pad);
+
+ case MSGSND:
+ return compat_ksys_msgsnd(first, ptr, second, third);
+
+ case MSGRCV: {
+ void __user *uptr = compat_ptr(ptr);
+
+ if (first < 0 || second < 0)
+ return -EINVAL;
+
+ if (!version) {
+ struct compat_ipc_kludge ipck;
+ if (!uptr)
+ return -EINVAL;
+ if (copy_from_user(&ipck, uptr, sizeof(ipck)))
+ return -EFAULT;
+ return compat_ksys_msgrcv(first, ipck.msgp, second,
+ ipck.msgtyp, third);
+ }
+ return compat_ksys_msgrcv(first, ptr, second, fifth, third);
+ }
+ case MSGGET:
+ return ksys_msgget(first, second);
+ case MSGCTL:
+ return compat_ksys_msgctl(first, second, compat_ptr(ptr));
+
+ case SHMAT: {
+ int err;
+ unsigned long raddr;
+
+ if (version == 1)
+ return -EINVAL;
+ err = do_shmat(first, compat_ptr(ptr), second, &raddr,
+ COMPAT_SHMLBA);
+ if (err < 0)
+ return err;
+ return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
+ }
+ case SHMDT:
+ return ksys_shmdt(compat_ptr(ptr));
+ case SHMGET:
+ return ksys_shmget(first, (unsigned int)second, third);
+ case SHMCTL:
+ return compat_ksys_shmctl(first, second, compat_ptr(ptr));
+ }
+
+ return -ENOSYS;
+}
+#endif
+#endif
diff --git a/ipc/util.c b/ipc/util.c
new file mode 100644
index 0000000..0af0575
--- /dev/null
+++ b/ipc/util.c
@@ -0,0 +1,864 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/ipc/util.c
+ * Copyright (C) 1992 Krishna Balasubramanian
+ *
+ * Sep 1997 - Call suser() last after "normal" permission checks so we
+ * get BSD style process accounting right.
+ * Occurs in several places in the IPC code.
+ * Chris Evans, <chris@ferret.lmh.ox.ac.uk>
+ * Nov 1999 - ipc helper functions, unified SMP locking
+ * Manfred Spraul <manfred@colorfullife.com>
+ * Oct 2002 - One lock per IPC id. RCU ipc_free for lock-free grow_ary().
+ * Mingming Cao <cmm@us.ibm.com>
+ * Mar 2006 - support for audit of ipc object properties
+ * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ * Jun 2006 - namespaces ssupport
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ *
+ * General sysv ipc locking scheme:
+ * rcu_read_lock()
+ * obtain the ipc object (kern_ipc_perm) by looking up the id in an idr
+ * tree.
+ * - perform initial checks (capabilities, auditing and permission,
+ * etc).
+ * - perform read-only operations, such as INFO command, that
+ * do not demand atomicity
+ * acquire the ipc lock (kern_ipc_perm.lock) through
+ * ipc_lock_object()
+ * - perform read-only operations that demand atomicity,
+ * such as STAT command.
+ * - perform data updates, such as SET, RMID commands and
+ * mechanism-specific operations (semop/semtimedop,
+ * msgsnd/msgrcv, shmat/shmdt).
+ * drop the ipc lock, through ipc_unlock_object().
+ * rcu_read_unlock()
+ *
+ * The ids->rwsem must be taken when:
+ * - creating, removing and iterating the existing entries in ipc
+ * identifier sets.
+ * - iterating through files under /proc/sysvipc/
+ *
+ * Note that sems have a special fast path that avoids kern_ipc_perm.lock -
+ * see sem_lock().
+ */
+
+#include <linux/mm.h>
+#include <linux/shm.h>
+#include <linux/init.h>
+#include <linux/msg.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+#include <linux/capability.h>
+#include <linux/highuid.h>
+#include <linux/security.h>
+#include <linux/rcupdate.h>
+#include <linux/workqueue.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/audit.h>
+#include <linux/nsproxy.h>
+#include <linux/rwsem.h>
+#include <linux/memory.h>
+#include <linux/ipc_namespace.h>
+#include <linux/rhashtable.h>
+
+#include <asm/unistd.h>
+
+#include "util.h"
+
+struct ipc_proc_iface {
+ const char *path;
+ const char *header;
+ int ids;
+ int (*show)(struct seq_file *, void *);
+};
+
+/**
+ * ipc_init - initialise ipc subsystem
+ *
+ * The various sysv ipc resources (semaphores, messages and shared
+ * memory) are initialised.
+ *
+ * A callback routine is registered into the memory hotplug notifier
+ * chain: since msgmni scales to lowmem this callback routine will be
+ * called upon successful memory add / remove to recompute msmgni.
+ */
+static int __init ipc_init(void)
+{
+ proc_mkdir("sysvipc", NULL);
+ sem_init();
+ msg_init();
+ shm_init();
+
+ return 0;
+}
+device_initcall(ipc_init);
+
+static const struct rhashtable_params ipc_kht_params = {
+ .head_offset = offsetof(struct kern_ipc_perm, khtnode),
+ .key_offset = offsetof(struct kern_ipc_perm, key),
+ .key_len = FIELD_SIZEOF(struct kern_ipc_perm, key),
+ .locks_mul = 1,
+ .automatic_shrinking = true,
+};
+
+/**
+ * ipc_init_ids - initialise ipc identifiers
+ * @ids: ipc identifier set
+ *
+ * Set up the sequence range to use for the ipc identifier range (limited
+ * below IPCMNI) then initialise the keys hashtable and ids idr.
+ */
+void ipc_init_ids(struct ipc_ids *ids)
+{
+ ids->in_use = 0;
+ ids->seq = 0;
+ init_rwsem(&ids->rwsem);
+ rhashtable_init(&ids->key_ht, &ipc_kht_params);
+ idr_init(&ids->ipcs_idr);
+ ids->max_idx = -1;
+#ifdef CONFIG_CHECKPOINT_RESTORE
+ ids->next_id = -1;
+#endif
+}
+
+#ifdef CONFIG_PROC_FS
+static const struct file_operations sysvipc_proc_fops;
+/**
+ * ipc_init_proc_interface - create a proc interface for sysipc types using a seq_file interface.
+ * @path: Path in procfs
+ * @header: Banner to be printed at the beginning of the file.
+ * @ids: ipc id table to iterate.
+ * @show: show routine.
+ */
+void __init ipc_init_proc_interface(const char *path, const char *header,
+ int ids, int (*show)(struct seq_file *, void *))
+{
+ struct proc_dir_entry *pde;
+ struct ipc_proc_iface *iface;
+
+ iface = kmalloc(sizeof(*iface), GFP_KERNEL);
+ if (!iface)
+ return;
+ iface->path = path;
+ iface->header = header;
+ iface->ids = ids;
+ iface->show = show;
+
+ pde = proc_create_data(path,
+ S_IRUGO, /* world readable */
+ NULL, /* parent dir */
+ &sysvipc_proc_fops,
+ iface);
+ if (!pde)
+ kfree(iface);
+}
+#endif
+
+/**
+ * ipc_findkey - find a key in an ipc identifier set
+ * @ids: ipc identifier set
+ * @key: key to find
+ *
+ * Returns the locked pointer to the ipc structure if found or NULL
+ * otherwise. If key is found ipc points to the owning ipc structure
+ *
+ * Called with writer ipc_ids.rwsem held.
+ */
+static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
+{
+ struct kern_ipc_perm *ipcp;
+
+ ipcp = rhashtable_lookup_fast(&ids->key_ht, &key,
+ ipc_kht_params);
+ if (!ipcp)
+ return NULL;
+
+ rcu_read_lock();
+ ipc_lock_object(ipcp);
+ return ipcp;
+}
+
+/*
+ * Insert new IPC object into idr tree, and set sequence number and id
+ * in the correct order.
+ * Especially:
+ * - the sequence number must be set before inserting the object into the idr,
+ * because the sequence number is accessed without a lock.
+ * - the id can/must be set after inserting the object into the idr.
+ * All accesses must be done after getting kern_ipc_perm.lock.
+ *
+ * The caller must own kern_ipc_perm.lock.of the new object.
+ * On error, the function returns a (negative) error code.
+ */
+static inline int ipc_idr_alloc(struct ipc_ids *ids, struct kern_ipc_perm *new)
+{
+ int idx, next_id = -1;
+
+#ifdef CONFIG_CHECKPOINT_RESTORE
+ next_id = ids->next_id;
+ ids->next_id = -1;
+#endif
+
+ /*
+ * As soon as a new object is inserted into the idr,
+ * ipc_obtain_object_idr() or ipc_obtain_object_check() can find it,
+ * and the lockless preparations for ipc operations can start.
+ * This means especially: permission checks, audit calls, allocation
+ * of undo structures, ...
+ *
+ * Thus the object must be fully initialized, and if something fails,
+ * then the full tear-down sequence must be followed.
+ * (i.e.: set new->deleted, reduce refcount, call_rcu())
+ */
+
+ if (next_id < 0) { /* !CHECKPOINT_RESTORE or next_id is unset */
+ new->seq = ids->seq++;
+ if (ids->seq > IPCID_SEQ_MAX)
+ ids->seq = 0;
+ idx = idr_alloc(&ids->ipcs_idr, new, 0, 0, GFP_NOWAIT);
+ } else {
+ new->seq = ipcid_to_seqx(next_id);
+ idx = idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id),
+ 0, GFP_NOWAIT);
+ }
+ if (idx >= 0)
+ new->id = SEQ_MULTIPLIER * new->seq + idx;
+ return idx;
+}
+
+/**
+ * ipc_addid - add an ipc identifier
+ * @ids: ipc identifier set
+ * @new: new ipc permission set
+ * @limit: limit for the number of used ids
+ *
+ * Add an entry 'new' to the ipc ids idr. The permissions object is
+ * initialised and the first free entry is set up and the index assigned
+ * is returned. The 'new' entry is returned in a locked state on success.
+ *
+ * On failure the entry is not locked and a negative err-code is returned.
+ * The caller must use ipc_rcu_putref() to free the identifier.
+ *
+ * Called with writer ipc_ids.rwsem held.
+ */
+int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit)
+{
+ kuid_t euid;
+ kgid_t egid;
+ int idx, err;
+
+ /* 1) Initialize the refcount so that ipc_rcu_putref works */
+ refcount_set(&new->refcount, 1);
+
+ if (limit > IPCMNI)
+ limit = IPCMNI;
+
+ if (ids->in_use >= limit)
+ return -ENOSPC;
+
+ idr_preload(GFP_KERNEL);
+
+ spin_lock_init(&new->lock);
+ rcu_read_lock();
+ spin_lock(&new->lock);
+
+ current_euid_egid(&euid, &egid);
+ new->cuid = new->uid = euid;
+ new->gid = new->cgid = egid;
+
+ new->deleted = false;
+
+ idx = ipc_idr_alloc(ids, new);
+ idr_preload_end();
+
+ if (idx >= 0 && new->key != IPC_PRIVATE) {
+ err = rhashtable_insert_fast(&ids->key_ht, &new->khtnode,
+ ipc_kht_params);
+ if (err < 0) {
+ idr_remove(&ids->ipcs_idr, idx);
+ idx = err;
+ }
+ }
+ if (idx < 0) {
+ new->deleted = true;
+ spin_unlock(&new->lock);
+ rcu_read_unlock();
+ return idx;
+ }
+
+ ids->in_use++;
+ if (idx > ids->max_idx)
+ ids->max_idx = idx;
+ return idx;
+}
+
+/**
+ * ipcget_new - create a new ipc object
+ * @ns: ipc namespace
+ * @ids: ipc identifier set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget, sys_semget() and sys_shmget()
+ * when the key is IPC_PRIVATE.
+ */
+static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
+ const struct ipc_ops *ops, struct ipc_params *params)
+{
+ int err;
+
+ down_write(&ids->rwsem);
+ err = ops->getnew(ns, params);
+ up_write(&ids->rwsem);
+ return err;
+}
+
+/**
+ * ipc_check_perms - check security and permissions for an ipc object
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @ops: the actual security routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
+ * when the key is not IPC_PRIVATE and that key already exists in the
+ * ds IDR.
+ *
+ * On success, the ipc id is returned.
+ *
+ * It is called with ipc_ids.rwsem and ipcp->lock held.
+ */
+static int ipc_check_perms(struct ipc_namespace *ns,
+ struct kern_ipc_perm *ipcp,
+ const struct ipc_ops *ops,
+ struct ipc_params *params)
+{
+ int err;
+
+ if (ipcperms(ns, ipcp, params->flg))
+ err = -EACCES;
+ else {
+ err = ops->associate(ipcp, params->flg);
+ if (!err)
+ err = ipcp->id;
+ }
+
+ return err;
+}
+
+/**
+ * ipcget_public - get an ipc object or create a new one
+ * @ns: ipc namespace
+ * @ids: ipc identifier set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget, sys_semget() and sys_shmget()
+ * when the key is not IPC_PRIVATE.
+ * It adds a new entry if the key is not found and does some permission
+ * / security checkings if the key is found.
+ *
+ * On success, the ipc id is returned.
+ */
+static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
+ const struct ipc_ops *ops, struct ipc_params *params)
+{
+ struct kern_ipc_perm *ipcp;
+ int flg = params->flg;
+ int err;
+
+ /*
+ * Take the lock as a writer since we are potentially going to add
+ * a new entry + read locks are not "upgradable"
+ */
+ down_write(&ids->rwsem);
+ ipcp = ipc_findkey(ids, params->key);
+ if (ipcp == NULL) {
+ /* key not used */
+ if (!(flg & IPC_CREAT))
+ err = -ENOENT;
+ else
+ err = ops->getnew(ns, params);
+ } else {
+ /* ipc object has been locked by ipc_findkey() */
+
+ if (flg & IPC_CREAT && flg & IPC_EXCL)
+ err = -EEXIST;
+ else {
+ err = 0;
+ if (ops->more_checks)
+ err = ops->more_checks(ipcp, params);
+ if (!err)
+ /*
+ * ipc_check_perms returns the IPC id on
+ * success
+ */
+ err = ipc_check_perms(ns, ipcp, ops, params);
+ }
+ ipc_unlock(ipcp);
+ }
+ up_write(&ids->rwsem);
+
+ return err;
+}
+
+/**
+ * ipc_kht_remove - remove an ipc from the key hashtable
+ * @ids: ipc identifier set
+ * @ipcp: ipc perm structure containing the key to remove
+ *
+ * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
+ * before this function is called, and remain locked on the exit.
+ */
+static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
+{
+ if (ipcp->key != IPC_PRIVATE)
+ rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode,
+ ipc_kht_params);
+}
+
+/**
+ * ipc_rmid - remove an ipc identifier
+ * @ids: ipc identifier set
+ * @ipcp: ipc perm structure containing the identifier to remove
+ *
+ * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
+ * before this function is called, and remain locked on the exit.
+ */
+void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
+{
+ int idx = ipcid_to_idx(ipcp->id);
+
+ idr_remove(&ids->ipcs_idr, idx);
+ ipc_kht_remove(ids, ipcp);
+ ids->in_use--;
+ ipcp->deleted = true;
+
+ if (unlikely(idx == ids->max_idx)) {
+ do {
+ idx--;
+ if (idx == -1)
+ break;
+ } while (!idr_find(&ids->ipcs_idr, idx));
+ ids->max_idx = idx;
+ }
+}
+
+/**
+ * ipc_set_key_private - switch the key of an existing ipc to IPC_PRIVATE
+ * @ids: ipc identifier set
+ * @ipcp: ipc perm structure containing the key to modify
+ *
+ * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
+ * before this function is called, and remain locked on the exit.
+ */
+void ipc_set_key_private(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
+{
+ ipc_kht_remove(ids, ipcp);
+ ipcp->key = IPC_PRIVATE;
+}
+
+bool ipc_rcu_getref(struct kern_ipc_perm *ptr)
+{
+ return refcount_inc_not_zero(&ptr->refcount);
+}
+
+void ipc_rcu_putref(struct kern_ipc_perm *ptr,
+ void (*func)(struct rcu_head *head))
+{
+ if (!refcount_dec_and_test(&ptr->refcount))
+ return;
+
+ call_rcu(&ptr->rcu, func);
+}
+
+/**
+ * ipcperms - check ipc permissions
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @flag: desired permission set
+ *
+ * Check user, group, other permissions for access
+ * to ipc resources. return 0 if allowed
+ *
+ * @flag will most probably be 0 or ``S_...UGO`` from <linux/stat.h>
+ */
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
+{
+ kuid_t euid = current_euid();
+ int requested_mode, granted_mode;
+
+ audit_ipc_obj(ipcp);
+ requested_mode = (flag >> 6) | (flag >> 3) | flag;
+ granted_mode = ipcp->mode;
+ if (uid_eq(euid, ipcp->cuid) ||
+ uid_eq(euid, ipcp->uid))
+ granted_mode >>= 6;
+ else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
+ granted_mode >>= 3;
+ /* is there some bit set in requested_mode but not in granted_mode? */
+ if ((requested_mode & ~granted_mode & 0007) &&
+ !ns_capable(ns->user_ns, CAP_IPC_OWNER))
+ return -1;
+
+ return security_ipc_permission(ipcp, flag);
+}
+
+/*
+ * Functions to convert between the kern_ipc_perm structure and the
+ * old/new ipc_perm structures
+ */
+
+/**
+ * kernel_to_ipc64_perm - convert kernel ipc permissions to user
+ * @in: kernel permissions
+ * @out: new style ipc permissions
+ *
+ * Turn the kernel object @in into a set of permissions descriptions
+ * for returning to userspace (@out).
+ */
+void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
+{
+ out->key = in->key;
+ out->uid = from_kuid_munged(current_user_ns(), in->uid);
+ out->gid = from_kgid_munged(current_user_ns(), in->gid);
+ out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
+ out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
+ out->mode = in->mode;
+ out->seq = in->seq;
+}
+
+/**
+ * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
+ * @in: new style ipc permissions
+ * @out: old style ipc permissions
+ *
+ * Turn the new style permissions object @in into a compatibility
+ * object and store it into the @out pointer.
+ */
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
+{
+ out->key = in->key;
+ SET_UID(out->uid, in->uid);
+ SET_GID(out->gid, in->gid);
+ SET_UID(out->cuid, in->cuid);
+ SET_GID(out->cgid, in->cgid);
+ out->mode = in->mode;
+ out->seq = in->seq;
+}
+
+/**
+ * ipc_obtain_object_idr
+ * @ids: ipc identifier set
+ * @id: ipc id to look for
+ *
+ * Look for an id in the ipc ids idr and return associated ipc object.
+ *
+ * Call inside the RCU critical section.
+ * The ipc object is *not* locked on exit.
+ */
+struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
+{
+ struct kern_ipc_perm *out;
+ int idx = ipcid_to_idx(id);
+
+ out = idr_find(&ids->ipcs_idr, idx);
+ if (!out)
+ return ERR_PTR(-EINVAL);
+
+ return out;
+}
+
+/**
+ * ipc_obtain_object_check
+ * @ids: ipc identifier set
+ * @id: ipc id to look for
+ *
+ * Similar to ipc_obtain_object_idr() but also checks the ipc object
+ * sequence number.
+ *
+ * Call inside the RCU critical section.
+ * The ipc object is *not* locked on exit.
+ */
+struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
+{
+ struct kern_ipc_perm *out = ipc_obtain_object_idr(ids, id);
+
+ if (IS_ERR(out))
+ goto out;
+
+ if (ipc_checkid(out, id))
+ return ERR_PTR(-EINVAL);
+out:
+ return out;
+}
+
+/**
+ * ipcget - Common sys_*get() code
+ * @ns: namespace
+ * @ids: ipc identifier set
+ * @ops: operations to be called on ipc object creation, permission checks
+ * and further checks
+ * @params: the parameters needed by the previous operations.
+ *
+ * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
+ */
+int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
+ const struct ipc_ops *ops, struct ipc_params *params)
+{
+ if (params->key == IPC_PRIVATE)
+ return ipcget_new(ns, ids, ops, params);
+ else
+ return ipcget_public(ns, ids, ops, params);
+}
+
+/**
+ * ipc_update_perm - update the permissions of an ipc object
+ * @in: the permission given as input.
+ * @out: the permission of the ipc to set.
+ */
+int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
+{
+ kuid_t uid = make_kuid(current_user_ns(), in->uid);
+ kgid_t gid = make_kgid(current_user_ns(), in->gid);
+ if (!uid_valid(uid) || !gid_valid(gid))
+ return -EINVAL;
+
+ out->uid = uid;
+ out->gid = gid;
+ out->mode = (out->mode & ~S_IRWXUGO)
+ | (in->mode & S_IRWXUGO);
+
+ return 0;
+}
+
+/**
+ * ipcctl_obtain_check - retrieve an ipc object and check permissions
+ * @ns: ipc namespace
+ * @ids: the table of ids where to look for the ipc
+ * @id: the id of the ipc to retrieve
+ * @cmd: the cmd to check
+ * @perm: the permission to set
+ * @extra_perm: one extra permission parameter used by msq
+ *
+ * This function does some common audit and permissions check for some IPC_XXX
+ * cmd and is called from semctl_down, shmctl_down and msgctl_down.
+ *
+ * It:
+ * - retrieves the ipc object with the given id in the given table.
+ * - performs some audit and permission check, depending on the given cmd
+ * - returns a pointer to the ipc object or otherwise, the corresponding
+ * error.
+ *
+ * Call holding the both the rwsem and the rcu read lock.
+ */
+struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,
+ struct ipc_ids *ids, int id, int cmd,
+ struct ipc64_perm *perm, int extra_perm)
+{
+ kuid_t euid;
+ int err = -EPERM;
+ struct kern_ipc_perm *ipcp;
+
+ ipcp = ipc_obtain_object_check(ids, id);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto err;
+ }
+
+ audit_ipc_obj(ipcp);
+ if (cmd == IPC_SET)
+ audit_ipc_set_perm(extra_perm, perm->uid,
+ perm->gid, perm->mode);
+
+ euid = current_euid();
+ if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
+ ns_capable(ns->user_ns, CAP_SYS_ADMIN))
+ return ipcp; /* successful lookup */
+err:
+ return ERR_PTR(err);
+}
+
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+
+
+/**
+ * ipc_parse_version - ipc call version
+ * @cmd: pointer to command
+ *
+ * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
+ * The @cmd value is turned from an encoding command and version into
+ * just the command code.
+ */
+int ipc_parse_version(int *cmd)
+{
+ if (*cmd & IPC_64) {
+ *cmd ^= IPC_64;
+ return IPC_64;
+ } else {
+ return IPC_OLD;
+ }
+}
+
+#endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */
+
+#ifdef CONFIG_PROC_FS
+struct ipc_proc_iter {
+ struct ipc_namespace *ns;
+ struct pid_namespace *pid_ns;
+ struct ipc_proc_iface *iface;
+};
+
+struct pid_namespace *ipc_seq_pid_ns(struct seq_file *s)
+{
+ struct ipc_proc_iter *iter = s->private;
+ return iter->pid_ns;
+}
+
+/*
+ * This routine locks the ipc structure found at least at position pos.
+ */
+static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
+ loff_t *new_pos)
+{
+ struct kern_ipc_perm *ipc;
+ int total, id;
+
+ total = 0;
+ for (id = 0; id < pos && total < ids->in_use; id++) {
+ ipc = idr_find(&ids->ipcs_idr, id);
+ if (ipc != NULL)
+ total++;
+ }
+
+ if (total >= ids->in_use)
+ return NULL;
+
+ for (; pos < IPCMNI; pos++) {
+ ipc = idr_find(&ids->ipcs_idr, pos);
+ if (ipc != NULL) {
+ *new_pos = pos + 1;
+ rcu_read_lock();
+ ipc_lock_object(ipc);
+ return ipc;
+ }
+ }
+
+ /* Out of range - return NULL to terminate iteration */
+ return NULL;
+}
+
+static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
+{
+ struct ipc_proc_iter *iter = s->private;
+ struct ipc_proc_iface *iface = iter->iface;
+ struct kern_ipc_perm *ipc = it;
+
+ /* If we had an ipc id locked before, unlock it */
+ if (ipc && ipc != SEQ_START_TOKEN)
+ ipc_unlock(ipc);
+
+ return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
+}
+
+/*
+ * File positions: pos 0 -> header, pos n -> ipc id = n - 1.
+ * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START.
+ */
+static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
+{
+ struct ipc_proc_iter *iter = s->private;
+ struct ipc_proc_iface *iface = iter->iface;
+ struct ipc_ids *ids;
+
+ ids = &iter->ns->ids[iface->ids];
+
+ /*
+ * Take the lock - this will be released by the corresponding
+ * call to stop().
+ */
+ down_read(&ids->rwsem);
+
+ /* pos < 0 is invalid */
+ if (*pos < 0)
+ return NULL;
+
+ /* pos == 0 means header */
+ if (*pos == 0)
+ return SEQ_START_TOKEN;
+
+ /* Find the (pos-1)th ipc */
+ return sysvipc_find_ipc(ids, *pos - 1, pos);
+}
+
+static void sysvipc_proc_stop(struct seq_file *s, void *it)
+{
+ struct kern_ipc_perm *ipc = it;
+ struct ipc_proc_iter *iter = s->private;
+ struct ipc_proc_iface *iface = iter->iface;
+ struct ipc_ids *ids;
+
+ /* If we had a locked structure, release it */
+ if (ipc && ipc != SEQ_START_TOKEN)
+ ipc_unlock(ipc);
+
+ ids = &iter->ns->ids[iface->ids];
+ /* Release the lock we took in start() */
+ up_read(&ids->rwsem);
+}
+
+static int sysvipc_proc_show(struct seq_file *s, void *it)
+{
+ struct ipc_proc_iter *iter = s->private;
+ struct ipc_proc_iface *iface = iter->iface;
+
+ if (it == SEQ_START_TOKEN) {
+ seq_puts(s, iface->header);
+ return 0;
+ }
+
+ return iface->show(s, it);
+}
+
+static const struct seq_operations sysvipc_proc_seqops = {
+ .start = sysvipc_proc_start,
+ .stop = sysvipc_proc_stop,
+ .next = sysvipc_proc_next,
+ .show = sysvipc_proc_show,
+};
+
+static int sysvipc_proc_open(struct inode *inode, struct file *file)
+{
+ struct ipc_proc_iter *iter;
+
+ iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter));
+ if (!iter)
+ return -ENOMEM;
+
+ iter->iface = PDE_DATA(inode);
+ iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
+ iter->pid_ns = get_pid_ns(task_active_pid_ns(current));
+
+ return 0;
+}
+
+static int sysvipc_proc_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ struct ipc_proc_iter *iter = seq->private;
+ put_ipc_ns(iter->ns);
+ put_pid_ns(iter->pid_ns);
+ return seq_release_private(inode, file);
+}
+
+static const struct file_operations sysvipc_proc_fops = {
+ .open = sysvipc_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = sysvipc_proc_release,
+};
+#endif /* CONFIG_PROC_FS */
diff --git a/ipc/util.h b/ipc/util.h
new file mode 100644
index 0000000..0a159f6
--- /dev/null
+++ b/ipc/util.h
@@ -0,0 +1,280 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/ipc/util.h
+ * Copyright (C) 1999 Christoph Rohland
+ *
+ * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
+ * namespaces support. 2006 OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
+ */
+
+#ifndef _IPC_UTIL_H
+#define _IPC_UTIL_H
+
+#include <linux/unistd.h>
+#include <linux/err.h>
+#include <linux/ipc_namespace.h>
+
+#define IPCMNI 32768 /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
+#define SEQ_MULTIPLIER (IPCMNI)
+
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
+
+struct ipc_namespace;
+struct pid_namespace;
+
+#ifdef CONFIG_POSIX_MQUEUE
+extern void mq_clear_sbinfo(struct ipc_namespace *ns);
+extern void mq_put_mnt(struct ipc_namespace *ns);
+#else
+static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
+static inline void mq_put_mnt(struct ipc_namespace *ns) { }
+#endif
+
+#ifdef CONFIG_SYSVIPC
+void sem_init_ns(struct ipc_namespace *ns);
+void msg_init_ns(struct ipc_namespace *ns);
+void shm_init_ns(struct ipc_namespace *ns);
+
+void sem_exit_ns(struct ipc_namespace *ns);
+void msg_exit_ns(struct ipc_namespace *ns);
+void shm_exit_ns(struct ipc_namespace *ns);
+#else
+static inline void sem_init_ns(struct ipc_namespace *ns) { }
+static inline void msg_init_ns(struct ipc_namespace *ns) { }
+static inline void shm_init_ns(struct ipc_namespace *ns) { }
+
+static inline void sem_exit_ns(struct ipc_namespace *ns) { }
+static inline void msg_exit_ns(struct ipc_namespace *ns) { }
+static inline void shm_exit_ns(struct ipc_namespace *ns) { }
+#endif
+
+/*
+ * Structure that holds the parameters needed by the ipc operations
+ * (see after)
+ */
+struct ipc_params {
+ key_t key;
+ int flg;
+ union {
+ size_t size; /* for shared memories */
+ int nsems; /* for semaphores */
+ } u; /* holds the getnew() specific param */
+};
+
+/*
+ * Structure that holds some ipc operations. This structure is used to unify
+ * the calls to sys_msgget(), sys_semget(), sys_shmget()
+ * . routine to call to create a new ipc object. Can be one of newque,
+ * newary, newseg
+ * . routine to call to check permissions for a new ipc object.
+ * Can be one of security_msg_associate, security_sem_associate,
+ * security_shm_associate
+ * . routine to call for an extra check if needed
+ */
+struct ipc_ops {
+ int (*getnew)(struct ipc_namespace *, struct ipc_params *);
+ int (*associate)(struct kern_ipc_perm *, int);
+ int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *);
+};
+
+struct seq_file;
+struct ipc_ids;
+
+void ipc_init_ids(struct ipc_ids *ids);
+#ifdef CONFIG_PROC_FS
+void __init ipc_init_proc_interface(const char *path, const char *header,
+ int ids, int (*show)(struct seq_file *, void *));
+struct pid_namespace *ipc_seq_pid_ns(struct seq_file *);
+#else
+#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
+#endif
+
+#define IPC_SEM_IDS 0
+#define IPC_MSG_IDS 1
+#define IPC_SHM_IDS 2
+
+#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
+#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
+
+/* must be called with ids->rwsem acquired for writing */
+int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
+
+/* must be called with both locks acquired. */
+void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
+
+/* must be called with both locks acquired. */
+void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *);
+
+/* must be called with ipcp locked */
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
+
+/**
+ * ipc_get_maxidx - get the highest assigned index
+ * @ids: ipc identifier set
+ *
+ * Called with ipc_ids.rwsem held for reading.
+ */
+static inline int ipc_get_maxidx(struct ipc_ids *ids)
+{
+ if (ids->in_use == 0)
+ return -1;
+
+ if (ids->in_use == IPCMNI)
+ return IPCMNI - 1;
+
+ return ids->max_idx;
+}
+
+/*
+ * For allocation that need to be freed by RCU.
+ * Objects are reference counted, they start with reference count 1.
+ * getref increases the refcount, the putref call that reduces the recount
+ * to 0 schedules the rcu destruction. Caller must guarantee locking.
+ *
+ * refcount is initialized by ipc_addid(), before that point call_rcu()
+ * must be used.
+ */
+bool ipc_rcu_getref(struct kern_ipc_perm *ptr);
+void ipc_rcu_putref(struct kern_ipc_perm *ptr,
+ void (*func)(struct rcu_head *head));
+
+struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);
+
+void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
+int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
+struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,
+ struct ipc_ids *ids, int id, int cmd,
+ struct ipc64_perm *perm, int extra_perm);
+
+static inline void ipc_update_pid(struct pid **pos, struct pid *pid)
+{
+ struct pid *old = *pos;
+ if (old != pid) {
+ *pos = get_pid(pid);
+ put_pid(old);
+ }
+}
+
+#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+/* On IA-64, we always use the "64-bit version" of the IPC structures. */
+# define ipc_parse_version(cmd) IPC_64
+#else
+int ipc_parse_version(int *cmd);
+#endif
+
+extern void free_msg(struct msg_msg *msg);
+extern struct msg_msg *load_msg(const void __user *src, size_t len);
+extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
+extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len);
+
+static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id)
+{
+ return ipcid_to_seqx(id) != ipcp->seq;
+}
+
+static inline void ipc_lock_object(struct kern_ipc_perm *perm)
+{
+ spin_lock(&perm->lock);
+}
+
+static inline void ipc_unlock_object(struct kern_ipc_perm *perm)
+{
+ spin_unlock(&perm->lock);
+}
+
+static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm)
+{
+ assert_spin_locked(&perm->lock);
+}
+
+static inline void ipc_unlock(struct kern_ipc_perm *perm)
+{
+ ipc_unlock_object(perm);
+ rcu_read_unlock();
+}
+
+/*
+ * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths
+ * where the respective ipc_ids.rwsem is not being held down.
+ * Checks whether the ipc object is still around or if it's gone already, as
+ * ipc_rmid() may have already freed the ID while the ipc lock was spinning.
+ * Needs to be called with kern_ipc_perm.lock held -- exception made for one
+ * checkpoint case at sys_semtimedop() as noted in code commentary.
+ */
+static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
+{
+ return !perm->deleted;
+}
+
+struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
+int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
+ const struct ipc_ops *ops, struct ipc_params *params);
+void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
+ void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+struct compat_ipc_perm {
+ key_t key;
+ __compat_uid_t uid;
+ __compat_gid_t gid;
+ __compat_uid_t cuid;
+ __compat_gid_t cgid;
+ compat_mode_t mode;
+ unsigned short seq;
+};
+
+void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *);
+void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *);
+int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *);
+int get_compat_ipc64_perm(struct ipc64_perm *,
+ struct compat_ipc64_perm __user *);
+
+static inline int compat_ipc_parse_version(int *cmd)
+{
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+ int version = *cmd & IPC_64;
+ *cmd &= ~IPC_64;
+ return version;
+#else
+ return IPC_64;
+#endif
+}
+#endif
+
+/* for __ARCH_WANT_SYS_IPC */
+long ksys_semtimedop(int semid, struct sembuf __user *tsops,
+ unsigned int nsops,
+ const struct __kernel_timespec __user *timeout);
+long ksys_semget(key_t key, int nsems, int semflg);
+long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
+long ksys_msgget(key_t key, int msgflg);
+long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
+long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+ long msgtyp, int msgflg);
+long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
+ int msgflg);
+long ksys_shmget(key_t key, size_t size, int shmflg);
+long ksys_shmdt(char __user *shmaddr);
+long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
+
+/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
+long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
+ unsigned int nsops,
+ const struct compat_timespec __user *timeout);
+#ifdef CONFIG_COMPAT
+long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
+long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr);
+long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
+ compat_long_t msgtyp, int msgflg);
+long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
+ compat_ssize_t msgsz, int msgflg);
+long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr);
+#endif /* CONFIG_COMPAT */
+
+#endif