v4.19.13 snapshot.
diff --git a/fs/proc/base.c b/fs/proc/base.c
new file mode 100644
index 0000000..7e9f07b
--- /dev/null
+++ b/fs/proc/base.c
@@ -0,0 +1,3616 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/proc/base.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * proc base directory handling functions
+ *
+ * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
+ * Instead of using magical inumbers to determine the kind of object
+ * we allocate and fill in-core inodes upon lookup. They don't even
+ * go into icache. We cache the reference to task_struct upon lookup too.
+ * Eventually it should become a filesystem in its own. We don't use the
+ * rest of procfs anymore.
+ *
+ *
+ * Changelog:
+ * 17-Jan-2005
+ * Allan Bezerra
+ * Bruna Moreira <bruna.moreira@indt.org.br>
+ * Edjard Mota <edjard.mota@indt.org.br>
+ * Ilias Biris <ilias.biris@indt.org.br>
+ * Mauricio Lin <mauricio.lin@indt.org.br>
+ *
+ * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
+ *
+ * A new process specific entry (smaps) included in /proc. It shows the
+ * size of rss for each memory area. The maps entry lacks information
+ * about physical memory size (rss) for each mapped file, i.e.,
+ * rss information for executables and library files.
+ * This additional information is useful for any tools that need to know
+ * about physical memory consumption for a process specific library.
+ *
+ * Changelog:
+ * 21-Feb-2005
+ * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
+ * Pud inclusion in the page table walking.
+ *
+ * ChangeLog:
+ * 10-Mar-2005
+ * 10LE Instituto Nokia de Tecnologia - INdT:
+ * A better way to walks through the page table as suggested by Hugh Dickins.
+ *
+ * Simo Piiroinen <simo.piiroinen@nokia.com>:
+ * Smaps information related to shared, private, clean and dirty pages.
+ *
+ * Paul Mundt <paul.mundt@nokia.com>:
+ * Overall revision about smaps.
+ */
+
+#include <linux/uaccess.h>
+
+#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/init.h>
+#include <linux/capability.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/string.h>
+#include <linux/seq_file.h>
+#include <linux/namei.h>
+#include <linux/mnt_namespace.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/rcupdate.h>
+#include <linux/kallsyms.h>
+#include <linux/stacktrace.h>
+#include <linux/resource.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/security.h>
+#include <linux/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/printk.h>
+#include <linux/cache.h>
+#include <linux/cgroup.h>
+#include <linux/cpuset.h>
+#include <linux/audit.h>
+#include <linux/poll.h>
+#include <linux/nsproxy.h>
+#include <linux/oom.h>
+#include <linux/elf.h>
+#include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
+#include <linux/fs_struct.h>
+#include <linux/slab.h>
+#include <linux/sched/autogroup.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/coredump.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/stat.h>
+#include <linux/flex_array.h>
+#include <linux/posix-timers.h>
+#include <trace/events/oom.h>
+#include "internal.h"
+#include "fd.h"
+
+#include "../../lib/kstrtox.h"
+
+/* NOTE:
+ * Implementing inode permission operations in /proc is almost
+ * certainly an error. Permission checks need to happen during
+ * each system call not at open time. The reason is that most of
+ * what we wish to check for permissions in /proc varies at runtime.
+ *
+ * The classic example of a problem is opening file descriptors
+ * in /proc for a task before it execs a suid executable.
+ */
+
+static u8 nlink_tid __ro_after_init;
+static u8 nlink_tgid __ro_after_init;
+
+struct pid_entry {
+ const char *name;
+ unsigned int len;
+ umode_t mode;
+ const struct inode_operations *iop;
+ const struct file_operations *fop;
+ union proc_op op;
+};
+
+#define NOD(NAME, MODE, IOP, FOP, OP) { \
+ .name = (NAME), \
+ .len = sizeof(NAME) - 1, \
+ .mode = MODE, \
+ .iop = IOP, \
+ .fop = FOP, \
+ .op = OP, \
+}
+
+#define DIR(NAME, MODE, iops, fops) \
+ NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
+#define LNK(NAME, get_link) \
+ NOD(NAME, (S_IFLNK|S_IRWXUGO), \
+ &proc_pid_link_inode_operations, NULL, \
+ { .proc_get_link = get_link } )
+#define REG(NAME, MODE, fops) \
+ NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
+#define ONE(NAME, MODE, show) \
+ NOD(NAME, (S_IFREG|(MODE)), \
+ NULL, &proc_single_file_operations, \
+ { .proc_show = show } )
+
+/*
+ * Count the number of hardlinks for the pid_entry table, excluding the .
+ * and .. links.
+ */
+static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
+ unsigned int n)
+{
+ unsigned int i;
+ unsigned int count;
+
+ count = 2;
+ for (i = 0; i < n; ++i) {
+ if (S_ISDIR(entries[i].mode))
+ ++count;
+ }
+
+ return count;
+}
+
+static int get_task_root(struct task_struct *task, struct path *root)
+{
+ int result = -ENOENT;
+
+ task_lock(task);
+ if (task->fs) {
+ get_fs_root(task->fs, root);
+ result = 0;
+ }
+ task_unlock(task);
+ return result;
+}
+
+static int proc_cwd_link(struct dentry *dentry, struct path *path)
+{
+ struct task_struct *task = get_proc_task(d_inode(dentry));
+ int result = -ENOENT;
+
+ if (task) {
+ task_lock(task);
+ if (task->fs) {
+ get_fs_pwd(task->fs, path);
+ result = 0;
+ }
+ task_unlock(task);
+ put_task_struct(task);
+ }
+ return result;
+}
+
+static int proc_root_link(struct dentry *dentry, struct path *path)
+{
+ struct task_struct *task = get_proc_task(d_inode(dentry));
+ int result = -ENOENT;
+
+ if (task) {
+ result = get_task_root(task, path);
+ put_task_struct(task);
+ }
+ return result;
+}
+
+static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long arg_start, arg_end, env_start, env_end;
+ unsigned long pos, len;
+ char *page;
+
+ /* Check if process spawned far enough to have cmdline. */
+ if (!mm->env_end)
+ return 0;
+
+ spin_lock(&mm->arg_lock);
+ arg_start = mm->arg_start;
+ arg_end = mm->arg_end;
+ env_start = mm->env_start;
+ env_end = mm->env_end;
+ spin_unlock(&mm->arg_lock);
+
+ if (arg_start >= arg_end)
+ return 0;
+
+ /*
+ * We have traditionally allowed the user to re-write
+ * the argument strings and overflow the end result
+ * into the environment section. But only do that if
+ * the environment area is contiguous to the arguments.
+ */
+ if (env_start != arg_end || env_start >= env_end)
+ env_start = env_end = arg_end;
+
+ /* .. and limit it to a maximum of one page of slop */
+ if (env_end >= arg_end + PAGE_SIZE)
+ env_end = arg_end + PAGE_SIZE - 1;
+
+ /* We're not going to care if "*ppos" has high bits set */
+ pos = arg_start + *ppos;
+
+ /* .. but we do check the result is in the proper range */
+ if (pos < arg_start || pos >= env_end)
+ return 0;
+
+ /* .. and we never go past env_end */
+ if (env_end - pos < count)
+ count = env_end - pos;
+
+ page = (char *)__get_free_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ len = 0;
+ while (count) {
+ int got;
+ size_t size = min_t(size_t, PAGE_SIZE, count);
+ long offset;
+
+ /*
+ * Are we already starting past the official end?
+ * We always include the last byte that is *supposed*
+ * to be NUL
+ */
+ offset = (pos >= arg_end) ? pos - arg_end + 1 : 0;
+
+ got = access_remote_vm(mm, pos - offset, page, size + offset, FOLL_ANON);
+ if (got <= offset)
+ break;
+ got -= offset;
+
+ /* Don't walk past a NUL character once you hit arg_end */
+ if (pos + got >= arg_end) {
+ int n = 0;
+
+ /*
+ * If we started before 'arg_end' but ended up
+ * at or after it, we start the NUL character
+ * check at arg_end-1 (where we expect the normal
+ * EOF to be).
+ *
+ * NOTE! This is smaller than 'got', because
+ * pos + got >= arg_end
+ */
+ if (pos < arg_end)
+ n = arg_end - pos - 1;
+
+ /* Cut off at first NUL after 'n' */
+ got = n + strnlen(page+n, offset+got-n);
+ if (got < offset)
+ break;
+ got -= offset;
+
+ /* Include the NUL if it existed */
+ if (got < size)
+ got++;
+ }
+
+ got -= copy_to_user(buf, page+offset, got);
+ if (unlikely(!got)) {
+ if (!len)
+ len = -EFAULT;
+ break;
+ }
+ pos += got;
+ buf += got;
+ len += got;
+ count -= got;
+ }
+
+ free_page((unsigned long)page);
+ return len;
+}
+
+static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct mm_struct *mm;
+ ssize_t ret;
+
+ mm = get_task_mm(tsk);
+ if (!mm)
+ return 0;
+
+ ret = get_mm_cmdline(mm, buf, count, pos);
+ mmput(mm);
+ return ret;
+}
+
+static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct task_struct *tsk;
+ ssize_t ret;
+
+ BUG_ON(*pos < 0);
+
+ tsk = get_proc_task(file_inode(file));
+ if (!tsk)
+ return -ESRCH;
+ ret = get_task_cmdline(tsk, buf, count, pos);
+ put_task_struct(tsk);
+ if (ret > 0)
+ *pos += ret;
+ return ret;
+}
+
+static const struct file_operations proc_pid_cmdline_ops = {
+ .read = proc_pid_cmdline_read,
+ .llseek = generic_file_llseek,
+};
+
+#ifdef CONFIG_KALLSYMS
+/*
+ * Provides a wchan file via kallsyms in a proper one-value-per-file format.
+ * Returns the resolved symbol. If that fails, simply return the address.
+ */
+static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ unsigned long wchan;
+ char symname[KSYM_NAME_LEN];
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
+ goto print0;
+
+ wchan = get_wchan(task);
+ if (wchan && !lookup_symbol_name(wchan, symname)) {
+ seq_puts(m, symname);
+ return 0;
+ }
+
+print0:
+ seq_putc(m, '0');
+ return 0;
+}
+#endif /* CONFIG_KALLSYMS */
+
+static int lock_trace(struct task_struct *task)
+{
+ int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
+ if (err)
+ return err;
+ if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
+ mutex_unlock(&task->signal->cred_guard_mutex);
+ return -EPERM;
+ }
+ return 0;
+}
+
+static void unlock_trace(struct task_struct *task)
+{
+ mutex_unlock(&task->signal->cred_guard_mutex);
+}
+
+#ifdef CONFIG_STACKTRACE
+
+#define MAX_STACK_TRACE_DEPTH 64
+
+static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ struct stack_trace trace;
+ unsigned long *entries;
+ int err;
+
+ /*
+ * The ability to racily run the kernel stack unwinder on a running task
+ * and then observe the unwinder output is scary; while it is useful for
+ * debugging kernel issues, it can also allow an attacker to leak kernel
+ * stack contents.
+ * Doing this in a manner that is at least safe from races would require
+ * some work to ensure that the remote task can not be scheduled; and
+ * even then, this would still expose the unwinder as local attack
+ * surface.
+ * Therefore, this interface is restricted to root.
+ */
+ if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
+ return -EACCES;
+
+ entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
+ GFP_KERNEL);
+ if (!entries)
+ return -ENOMEM;
+
+ trace.nr_entries = 0;
+ trace.max_entries = MAX_STACK_TRACE_DEPTH;
+ trace.entries = entries;
+ trace.skip = 0;
+
+ err = lock_trace(task);
+ if (!err) {
+ unsigned int i;
+
+ save_stack_trace_tsk(task, &trace);
+
+ for (i = 0; i < trace.nr_entries; i++) {
+ seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
+ }
+ unlock_trace(task);
+ }
+ kfree(entries);
+
+ return err;
+}
+#endif
+
+#ifdef CONFIG_SCHED_INFO
+/*
+ * Provides /proc/PID/schedstat
+ */
+static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ if (unlikely(!sched_info_on()))
+ seq_printf(m, "0 0 0\n");
+ else
+ seq_printf(m, "%llu %llu %lu\n",
+ (unsigned long long)task->se.sum_exec_runtime,
+ (unsigned long long)task->sched_info.run_delay,
+ task->sched_info.pcount);
+
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_LATENCYTOP
+static int lstats_show_proc(struct seq_file *m, void *v)
+{
+ int i;
+ struct inode *inode = m->private;
+ struct task_struct *task = get_proc_task(inode);
+
+ if (!task)
+ return -ESRCH;
+ seq_puts(m, "Latency Top version : v0.1\n");
+ for (i = 0; i < LT_SAVECOUNT; i++) {
+ struct latency_record *lr = &task->latency_record[i];
+ if (lr->backtrace[0]) {
+ int q;
+ seq_printf(m, "%i %li %li",
+ lr->count, lr->time, lr->max);
+ for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
+ unsigned long bt = lr->backtrace[q];
+ if (!bt)
+ break;
+ if (bt == ULONG_MAX)
+ break;
+ seq_printf(m, " %ps", (void *)bt);
+ }
+ seq_putc(m, '\n');
+ }
+
+ }
+ put_task_struct(task);
+ return 0;
+}
+
+static int lstats_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, lstats_show_proc, inode);
+}
+
+static ssize_t lstats_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offs)
+{
+ struct task_struct *task = get_proc_task(file_inode(file));
+
+ if (!task)
+ return -ESRCH;
+ clear_all_latency_tracing(task);
+ put_task_struct(task);
+
+ return count;
+}
+
+static const struct file_operations proc_lstats_operations = {
+ .open = lstats_open,
+ .read = seq_read,
+ .write = lstats_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+#endif
+
+static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ unsigned long totalpages = totalram_pages + total_swap_pages;
+ unsigned long points = 0;
+
+ points = oom_badness(task, NULL, NULL, totalpages) *
+ 1000 / totalpages;
+ seq_printf(m, "%lu\n", points);
+
+ return 0;
+}
+
+struct limit_names {
+ const char *name;
+ const char *unit;
+};
+
+static const struct limit_names lnames[RLIM_NLIMITS] = {
+ [RLIMIT_CPU] = {"Max cpu time", "seconds"},
+ [RLIMIT_FSIZE] = {"Max file size", "bytes"},
+ [RLIMIT_DATA] = {"Max data size", "bytes"},
+ [RLIMIT_STACK] = {"Max stack size", "bytes"},
+ [RLIMIT_CORE] = {"Max core file size", "bytes"},
+ [RLIMIT_RSS] = {"Max resident set", "bytes"},
+ [RLIMIT_NPROC] = {"Max processes", "processes"},
+ [RLIMIT_NOFILE] = {"Max open files", "files"},
+ [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
+ [RLIMIT_AS] = {"Max address space", "bytes"},
+ [RLIMIT_LOCKS] = {"Max file locks", "locks"},
+ [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
+ [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
+ [RLIMIT_NICE] = {"Max nice priority", NULL},
+ [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
+ [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
+};
+
+/* Display limits for a process */
+static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ unsigned int i;
+ unsigned long flags;
+
+ struct rlimit rlim[RLIM_NLIMITS];
+
+ if (!lock_task_sighand(task, &flags))
+ return 0;
+ memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
+ unlock_task_sighand(task, &flags);
+
+ /*
+ * print the file header
+ */
+ seq_printf(m, "%-25s %-20s %-20s %-10s\n",
+ "Limit", "Soft Limit", "Hard Limit", "Units");
+
+ for (i = 0; i < RLIM_NLIMITS; i++) {
+ if (rlim[i].rlim_cur == RLIM_INFINITY)
+ seq_printf(m, "%-25s %-20s ",
+ lnames[i].name, "unlimited");
+ else
+ seq_printf(m, "%-25s %-20lu ",
+ lnames[i].name, rlim[i].rlim_cur);
+
+ if (rlim[i].rlim_max == RLIM_INFINITY)
+ seq_printf(m, "%-20s ", "unlimited");
+ else
+ seq_printf(m, "%-20lu ", rlim[i].rlim_max);
+
+ if (lnames[i].unit)
+ seq_printf(m, "%-10s\n", lnames[i].unit);
+ else
+ seq_putc(m, '\n');
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ long nr;
+ unsigned long args[6], sp, pc;
+ int res;
+
+ res = lock_trace(task);
+ if (res)
+ return res;
+
+ if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
+ seq_puts(m, "running\n");
+ else if (nr < 0)
+ seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
+ else
+ seq_printf(m,
+ "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
+ nr,
+ args[0], args[1], args[2], args[3], args[4], args[5],
+ sp, pc);
+ unlock_trace(task);
+
+ return 0;
+}
+#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
+
+/************************************************************************/
+/* Here the fs part begins */
+/************************************************************************/
+
+/* permission checks */
+static int proc_fd_access_allowed(struct inode *inode)
+{
+ struct task_struct *task;
+ int allowed = 0;
+ /* Allow access to a task's file descriptors if it is us or we
+ * may use ptrace attach to the process and find out that
+ * information.
+ */
+ task = get_proc_task(inode);
+ if (task) {
+ allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
+ put_task_struct(task);
+ }
+ return allowed;
+}
+
+int proc_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ int error;
+ struct inode *inode = d_inode(dentry);
+
+ if (attr->ia_valid & ATTR_MODE)
+ return -EPERM;
+
+ error = setattr_prepare(dentry, attr);
+ if (error)
+ return error;
+
+ setattr_copy(inode, attr);
+ mark_inode_dirty(inode);
+ return 0;
+}
+
+/*
+ * May current process learn task's sched/cmdline info (for hide_pid_min=1)
+ * or euid/egid (for hide_pid_min=2)?
+ */
+static bool has_pid_permissions(struct pid_namespace *pid,
+ struct task_struct *task,
+ int hide_pid_min)
+{
+ if (pid->hide_pid < hide_pid_min)
+ return true;
+ if (in_group_p(pid->pid_gid))
+ return true;
+ return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
+}
+
+
+static int proc_pid_permission(struct inode *inode, int mask)
+{
+ struct pid_namespace *pid = proc_pid_ns(inode);
+ struct task_struct *task;
+ bool has_perms;
+
+ task = get_proc_task(inode);
+ if (!task)
+ return -ESRCH;
+ has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
+ put_task_struct(task);
+
+ if (!has_perms) {
+ if (pid->hide_pid == HIDEPID_INVISIBLE) {
+ /*
+ * Let's make getdents(), stat(), and open()
+ * consistent with each other. If a process
+ * may not stat() a file, it shouldn't be seen
+ * in procfs at all.
+ */
+ return -ENOENT;
+ }
+
+ return -EPERM;
+ }
+ return generic_permission(inode, mask);
+}
+
+
+
+static const struct inode_operations proc_def_inode_operations = {
+ .setattr = proc_setattr,
+};
+
+static int proc_single_show(struct seq_file *m, void *v)
+{
+ struct inode *inode = m->private;
+ struct pid_namespace *ns = proc_pid_ns(inode);
+ struct pid *pid = proc_pid(inode);
+ struct task_struct *task;
+ int ret;
+
+ task = get_pid_task(pid, PIDTYPE_PID);
+ if (!task)
+ return -ESRCH;
+
+ ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
+
+ put_task_struct(task);
+ return ret;
+}
+
+static int proc_single_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, proc_single_show, inode);
+}
+
+static const struct file_operations proc_single_file_operations = {
+ .open = proc_single_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+
+struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
+{
+ struct task_struct *task = get_proc_task(inode);
+ struct mm_struct *mm = ERR_PTR(-ESRCH);
+
+ if (task) {
+ mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
+ put_task_struct(task);
+
+ if (!IS_ERR_OR_NULL(mm)) {
+ /* ensure this mm_struct can't be freed */
+ mmgrab(mm);
+ /* but do not pin its memory */
+ mmput(mm);
+ }
+ }
+
+ return mm;
+}
+
+static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
+{
+ struct mm_struct *mm = proc_mem_open(inode, mode);
+
+ if (IS_ERR(mm))
+ return PTR_ERR(mm);
+
+ file->private_data = mm;
+ return 0;
+}
+
+static int mem_open(struct inode *inode, struct file *file)
+{
+ int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
+
+ /* OK to pass negative loff_t, we can catch out-of-range */
+ file->f_mode |= FMODE_UNSIGNED_OFFSET;
+
+ return ret;
+}
+
+static ssize_t mem_rw(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos, int write)
+{
+ struct mm_struct *mm = file->private_data;
+ unsigned long addr = *ppos;
+ ssize_t copied;
+ char *page;
+ unsigned int flags;
+
+ if (!mm)
+ return 0;
+
+ page = (char *)__get_free_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ copied = 0;
+ if (!mmget_not_zero(mm))
+ goto free;
+
+ flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
+
+ while (count > 0) {
+ int this_len = min_t(int, count, PAGE_SIZE);
+
+ if (write && copy_from_user(page, buf, this_len)) {
+ copied = -EFAULT;
+ break;
+ }
+
+ this_len = access_remote_vm(mm, addr, page, this_len, flags);
+ if (!this_len) {
+ if (!copied)
+ copied = -EIO;
+ break;
+ }
+
+ if (!write && copy_to_user(buf, page, this_len)) {
+ copied = -EFAULT;
+ break;
+ }
+
+ buf += this_len;
+ addr += this_len;
+ copied += this_len;
+ count -= this_len;
+ }
+ *ppos = addr;
+
+ mmput(mm);
+free:
+ free_page((unsigned long) page);
+ return copied;
+}
+
+static ssize_t mem_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return mem_rw(file, buf, count, ppos, 0);
+}
+
+static ssize_t mem_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return mem_rw(file, (char __user*)buf, count, ppos, 1);
+}
+
+loff_t mem_lseek(struct file *file, loff_t offset, int orig)
+{
+ switch (orig) {
+ case 0:
+ file->f_pos = offset;
+ break;
+ case 1:
+ file->f_pos += offset;
+ break;
+ default:
+ return -EINVAL;
+ }
+ force_successful_syscall_return();
+ return file->f_pos;
+}
+
+static int mem_release(struct inode *inode, struct file *file)
+{
+ struct mm_struct *mm = file->private_data;
+ if (mm)
+ mmdrop(mm);
+ return 0;
+}
+
+static const struct file_operations proc_mem_operations = {
+ .llseek = mem_lseek,
+ .read = mem_read,
+ .write = mem_write,
+ .open = mem_open,
+ .release = mem_release,
+};
+
+static int environ_open(struct inode *inode, struct file *file)
+{
+ return __mem_open(inode, file, PTRACE_MODE_READ);
+}
+
+static ssize_t environ_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *page;
+ unsigned long src = *ppos;
+ int ret = 0;
+ struct mm_struct *mm = file->private_data;
+ unsigned long env_start, env_end;
+
+ /* Ensure the process spawned far enough to have an environment. */
+ if (!mm || !mm->env_end)
+ return 0;
+
+ page = (char *)__get_free_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ ret = 0;
+ if (!mmget_not_zero(mm))
+ goto free;
+
+ spin_lock(&mm->arg_lock);
+ env_start = mm->env_start;
+ env_end = mm->env_end;
+ spin_unlock(&mm->arg_lock);
+
+ while (count > 0) {
+ size_t this_len, max_len;
+ int retval;
+
+ if (src >= (env_end - env_start))
+ break;
+
+ this_len = env_end - (env_start + src);
+
+ max_len = min_t(size_t, PAGE_SIZE, count);
+ this_len = min(max_len, this_len);
+
+ retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
+
+ if (retval <= 0) {
+ ret = retval;
+ break;
+ }
+
+ if (copy_to_user(buf, page, retval)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ ret += retval;
+ src += retval;
+ buf += retval;
+ count -= retval;
+ }
+ *ppos = src;
+ mmput(mm);
+
+free:
+ free_page((unsigned long) page);
+ return ret;
+}
+
+static const struct file_operations proc_environ_operations = {
+ .open = environ_open,
+ .read = environ_read,
+ .llseek = generic_file_llseek,
+ .release = mem_release,
+};
+
+static int auxv_open(struct inode *inode, struct file *file)
+{
+ return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
+}
+
+static ssize_t auxv_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct mm_struct *mm = file->private_data;
+ unsigned int nwords = 0;
+
+ if (!mm)
+ return 0;
+ do {
+ nwords += 2;
+ } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
+ return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
+ nwords * sizeof(mm->saved_auxv[0]));
+}
+
+static const struct file_operations proc_auxv_operations = {
+ .open = auxv_open,
+ .read = auxv_read,
+ .llseek = generic_file_llseek,
+ .release = mem_release,
+};
+
+static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct task_struct *task = get_proc_task(file_inode(file));
+ char buffer[PROC_NUMBUF];
+ int oom_adj = OOM_ADJUST_MIN;
+ size_t len;
+
+ if (!task)
+ return -ESRCH;
+ if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
+ oom_adj = OOM_ADJUST_MAX;
+ else
+ oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
+ OOM_SCORE_ADJ_MAX;
+ put_task_struct(task);
+ len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
+ return simple_read_from_buffer(buf, count, ppos, buffer, len);
+}
+
+static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
+{
+ static DEFINE_MUTEX(oom_adj_mutex);
+ struct mm_struct *mm = NULL;
+ struct task_struct *task;
+ int err = 0;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+
+ mutex_lock(&oom_adj_mutex);
+ if (legacy) {
+ if (oom_adj < task->signal->oom_score_adj &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EACCES;
+ goto err_unlock;
+ }
+ /*
+ * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
+ * /proc/pid/oom_score_adj instead.
+ */
+ pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
+ current->comm, task_pid_nr(current), task_pid_nr(task),
+ task_pid_nr(task));
+ } else {
+ if ((short)oom_adj < task->signal->oom_score_adj_min &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EACCES;
+ goto err_unlock;
+ }
+ }
+
+ /*
+ * Make sure we will check other processes sharing the mm if this is
+ * not vfrok which wants its own oom_score_adj.
+ * pin the mm so it doesn't go away and get reused after task_unlock
+ */
+ if (!task->vfork_done) {
+ struct task_struct *p = find_lock_task_mm(task);
+
+ if (p) {
+ if (atomic_read(&p->mm->mm_users) > 1) {
+ mm = p->mm;
+ mmgrab(mm);
+ }
+ task_unlock(p);
+ }
+ }
+
+ task->signal->oom_score_adj = oom_adj;
+ if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
+ task->signal->oom_score_adj_min = (short)oom_adj;
+ trace_oom_score_adj_update(task);
+
+ if (mm) {
+ struct task_struct *p;
+
+ rcu_read_lock();
+ for_each_process(p) {
+ if (same_thread_group(task, p))
+ continue;
+
+ /* do not touch kernel threads or the global init */
+ if (p->flags & PF_KTHREAD || is_global_init(p))
+ continue;
+
+ task_lock(p);
+ if (!p->vfork_done && process_shares_mm(p, mm)) {
+ pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
+ task_pid_nr(p), p->comm,
+ p->signal->oom_score_adj, oom_adj,
+ task_pid_nr(task), task->comm);
+ p->signal->oom_score_adj = oom_adj;
+ if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
+ p->signal->oom_score_adj_min = (short)oom_adj;
+ }
+ task_unlock(p);
+ }
+ rcu_read_unlock();
+ mmdrop(mm);
+ }
+err_unlock:
+ mutex_unlock(&oom_adj_mutex);
+ put_task_struct(task);
+ return err;
+}
+
+/*
+ * /proc/pid/oom_adj exists solely for backwards compatibility with previous
+ * kernels. The effective policy is defined by oom_score_adj, which has a
+ * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
+ * Values written to oom_adj are simply mapped linearly to oom_score_adj.
+ * Processes that become oom disabled via oom_adj will still be oom disabled
+ * with this implementation.
+ *
+ * oom_adj cannot be removed since existing userspace binaries use it.
+ */
+static ssize_t oom_adj_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char buffer[PROC_NUMBUF];
+ int oom_adj;
+ int err;
+
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count)) {
+ err = -EFAULT;
+ goto out;
+ }
+
+ err = kstrtoint(strstrip(buffer), 0, &oom_adj);
+ if (err)
+ goto out;
+ if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
+ oom_adj != OOM_DISABLE) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
+ * value is always attainable.
+ */
+ if (oom_adj == OOM_ADJUST_MAX)
+ oom_adj = OOM_SCORE_ADJ_MAX;
+ else
+ oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
+
+ err = __set_oom_adj(file, oom_adj, true);
+out:
+ return err < 0 ? err : count;
+}
+
+static const struct file_operations proc_oom_adj_operations = {
+ .read = oom_adj_read,
+ .write = oom_adj_write,
+ .llseek = generic_file_llseek,
+};
+
+static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task = get_proc_task(file_inode(file));
+ char buffer[PROC_NUMBUF];
+ short oom_score_adj = OOM_SCORE_ADJ_MIN;
+ size_t len;
+
+ if (!task)
+ return -ESRCH;
+ oom_score_adj = task->signal->oom_score_adj;
+ put_task_struct(task);
+ len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
+ return simple_read_from_buffer(buf, count, ppos, buffer, len);
+}
+
+static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char buffer[PROC_NUMBUF];
+ int oom_score_adj;
+ int err;
+
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count)) {
+ err = -EFAULT;
+ goto out;
+ }
+
+ err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
+ if (err)
+ goto out;
+ if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
+ oom_score_adj > OOM_SCORE_ADJ_MAX) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = __set_oom_adj(file, oom_score_adj, false);
+out:
+ return err < 0 ? err : count;
+}
+
+static const struct file_operations proc_oom_score_adj_operations = {
+ .read = oom_score_adj_read,
+ .write = oom_score_adj_write,
+ .llseek = default_llseek,
+};
+
+#ifdef CONFIG_AUDITSYSCALL
+#define TMPBUFLEN 11
+static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file_inode(file);
+ struct task_struct *task = get_proc_task(inode);
+ ssize_t length;
+ char tmpbuf[TMPBUFLEN];
+
+ if (!task)
+ return -ESRCH;
+ length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
+ from_kuid(file->f_cred->user_ns,
+ audit_get_loginuid(task)));
+ put_task_struct(task);
+ return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}
+
+static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file_inode(file);
+ uid_t loginuid;
+ kuid_t kloginuid;
+ int rv;
+
+ rcu_read_lock();
+ if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
+ rcu_read_unlock();
+ return -EPERM;
+ }
+ rcu_read_unlock();
+
+ if (*ppos != 0) {
+ /* No partial writes. */
+ return -EINVAL;
+ }
+
+ rv = kstrtou32_from_user(buf, count, 10, &loginuid);
+ if (rv < 0)
+ return rv;
+
+ /* is userspace tring to explicitly UNSET the loginuid? */
+ if (loginuid == AUDIT_UID_UNSET) {
+ kloginuid = INVALID_UID;
+ } else {
+ kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
+ if (!uid_valid(kloginuid))
+ return -EINVAL;
+ }
+
+ rv = audit_set_loginuid(kloginuid);
+ if (rv < 0)
+ return rv;
+ return count;
+}
+
+static const struct file_operations proc_loginuid_operations = {
+ .read = proc_loginuid_read,
+ .write = proc_loginuid_write,
+ .llseek = generic_file_llseek,
+};
+
+static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file_inode(file);
+ struct task_struct *task = get_proc_task(inode);
+ ssize_t length;
+ char tmpbuf[TMPBUFLEN];
+
+ if (!task)
+ return -ESRCH;
+ length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
+ audit_get_sessionid(task));
+ put_task_struct(task);
+ return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}
+
+static const struct file_operations proc_sessionid_operations = {
+ .read = proc_sessionid_read,
+ .llseek = generic_file_llseek,
+};
+#endif
+
+#ifdef CONFIG_FAULT_INJECTION
+static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task = get_proc_task(file_inode(file));
+ char buffer[PROC_NUMBUF];
+ size_t len;
+ int make_it_fail;
+
+ if (!task)
+ return -ESRCH;
+ make_it_fail = task->make_it_fail;
+ put_task_struct(task);
+
+ len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
+
+ return simple_read_from_buffer(buf, count, ppos, buffer, len);
+}
+
+static ssize_t proc_fault_inject_write(struct file * file,
+ const char __user * buf, size_t count, loff_t *ppos)
+{
+ struct task_struct *task;
+ char buffer[PROC_NUMBUF];
+ int make_it_fail;
+ int rv;
+
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count))
+ return -EFAULT;
+ rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
+ if (rv < 0)
+ return rv;
+ if (make_it_fail < 0 || make_it_fail > 1)
+ return -EINVAL;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+ task->make_it_fail = make_it_fail;
+ put_task_struct(task);
+
+ return count;
+}
+
+static const struct file_operations proc_fault_inject_operations = {
+ .read = proc_fault_inject_read,
+ .write = proc_fault_inject_write,
+ .llseek = generic_file_llseek,
+};
+
+static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task;
+ int err;
+ unsigned int n;
+
+ err = kstrtouint_from_user(buf, count, 0, &n);
+ if (err)
+ return err;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+ task->fail_nth = n;
+ put_task_struct(task);
+
+ return count;
+}
+
+static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task;
+ char numbuf[PROC_NUMBUF];
+ ssize_t len;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+ len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
+ put_task_struct(task);
+ return simple_read_from_buffer(buf, count, ppos, numbuf, len);
+}
+
+static const struct file_operations proc_fail_nth_operations = {
+ .read = proc_fail_nth_read,
+ .write = proc_fail_nth_write,
+};
+#endif
+
+
+#ifdef CONFIG_SCHED_DEBUG
+/*
+ * Print out various scheduling related per-task fields:
+ */
+static int sched_show(struct seq_file *m, void *v)
+{
+ struct inode *inode = m->private;
+ struct pid_namespace *ns = proc_pid_ns(inode);
+ struct task_struct *p;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+ proc_sched_show_task(p, ns, m);
+
+ put_task_struct(p);
+
+ return 0;
+}
+
+static ssize_t
+sched_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offset)
+{
+ struct inode *inode = file_inode(file);
+ struct task_struct *p;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+ proc_sched_set_task(p);
+
+ put_task_struct(p);
+
+ return count;
+}
+
+static int sched_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_show, inode);
+}
+
+static const struct file_operations proc_pid_sched_operations = {
+ .open = sched_open,
+ .read = seq_read,
+ .write = sched_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+#endif
+
+#ifdef CONFIG_SCHED_AUTOGROUP
+/*
+ * Print out autogroup related information:
+ */
+static int sched_autogroup_show(struct seq_file *m, void *v)
+{
+ struct inode *inode = m->private;
+ struct task_struct *p;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+ proc_sched_autogroup_show_task(p, m);
+
+ put_task_struct(p);
+
+ return 0;
+}
+
+static ssize_t
+sched_autogroup_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offset)
+{
+ struct inode *inode = file_inode(file);
+ struct task_struct *p;
+ char buffer[PROC_NUMBUF];
+ int nice;
+ int err;
+
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count))
+ return -EFAULT;
+
+ err = kstrtoint(strstrip(buffer), 0, &nice);
+ if (err < 0)
+ return err;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+
+ err = proc_sched_autogroup_set_nice(p, nice);
+ if (err)
+ count = err;
+
+ put_task_struct(p);
+
+ return count;
+}
+
+static int sched_autogroup_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = single_open(filp, sched_autogroup_show, NULL);
+ if (!ret) {
+ struct seq_file *m = filp->private_data;
+
+ m->private = inode;
+ }
+ return ret;
+}
+
+static const struct file_operations proc_pid_sched_autogroup_operations = {
+ .open = sched_autogroup_open,
+ .read = seq_read,
+ .write = sched_autogroup_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+#endif /* CONFIG_SCHED_AUTOGROUP */
+
+static ssize_t comm_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offset)
+{
+ struct inode *inode = file_inode(file);
+ struct task_struct *p;
+ char buffer[TASK_COMM_LEN];
+ const size_t maxlen = sizeof(buffer) - 1;
+
+ memset(buffer, 0, sizeof(buffer));
+ if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
+ return -EFAULT;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+
+ if (same_thread_group(current, p))
+ set_task_comm(p, buffer);
+ else
+ count = -EINVAL;
+
+ put_task_struct(p);
+
+ return count;
+}
+
+static int comm_show(struct seq_file *m, void *v)
+{
+ struct inode *inode = m->private;
+ struct task_struct *p;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+
+ proc_task_name(m, p, false);
+ seq_putc(m, '\n');
+
+ put_task_struct(p);
+
+ return 0;
+}
+
+static int comm_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, comm_show, inode);
+}
+
+static const struct file_operations proc_pid_set_comm_operations = {
+ .open = comm_open,
+ .read = seq_read,
+ .write = comm_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
+{
+ struct task_struct *task;
+ struct file *exe_file;
+
+ task = get_proc_task(d_inode(dentry));
+ if (!task)
+ return -ENOENT;
+ exe_file = get_task_exe_file(task);
+ put_task_struct(task);
+ if (exe_file) {
+ *exe_path = exe_file->f_path;
+ path_get(&exe_file->f_path);
+ fput(exe_file);
+ return 0;
+ } else
+ return -ENOENT;
+}
+
+static const char *proc_pid_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
+{
+ struct path path;
+ int error = -EACCES;
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ /* Are we allowed to snoop on the tasks file descriptors? */
+ if (!proc_fd_access_allowed(inode))
+ goto out;
+
+ error = PROC_I(inode)->op.proc_get_link(dentry, &path);
+ if (error)
+ goto out;
+
+ nd_jump_link(&path);
+ return NULL;
+out:
+ return ERR_PTR(error);
+}
+
+static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
+{
+ char *tmp = (char *)__get_free_page(GFP_KERNEL);
+ char *pathname;
+ int len;
+
+ if (!tmp)
+ return -ENOMEM;
+
+ pathname = d_path(path, tmp, PAGE_SIZE);
+ len = PTR_ERR(pathname);
+ if (IS_ERR(pathname))
+ goto out;
+ len = tmp + PAGE_SIZE - 1 - pathname;
+
+ if (len > buflen)
+ len = buflen;
+ if (copy_to_user(buffer, pathname, len))
+ len = -EFAULT;
+ out:
+ free_page((unsigned long)tmp);
+ return len;
+}
+
+static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
+{
+ int error = -EACCES;
+ struct inode *inode = d_inode(dentry);
+ struct path path;
+
+ /* Are we allowed to snoop on the tasks file descriptors? */
+ if (!proc_fd_access_allowed(inode))
+ goto out;
+
+ error = PROC_I(inode)->op.proc_get_link(dentry, &path);
+ if (error)
+ goto out;
+
+ error = do_proc_readlink(&path, buffer, buflen);
+ path_put(&path);
+out:
+ return error;
+}
+
+const struct inode_operations proc_pid_link_inode_operations = {
+ .readlink = proc_pid_readlink,
+ .get_link = proc_pid_get_link,
+ .setattr = proc_setattr,
+};
+
+
+/* building an inode */
+
+void task_dump_owner(struct task_struct *task, umode_t mode,
+ kuid_t *ruid, kgid_t *rgid)
+{
+ /* Depending on the state of dumpable compute who should own a
+ * proc file for a task.
+ */
+ const struct cred *cred;
+ kuid_t uid;
+ kgid_t gid;
+
+ if (unlikely(task->flags & PF_KTHREAD)) {
+ *ruid = GLOBAL_ROOT_UID;
+ *rgid = GLOBAL_ROOT_GID;
+ return;
+ }
+
+ /* Default to the tasks effective ownership */
+ rcu_read_lock();
+ cred = __task_cred(task);
+ uid = cred->euid;
+ gid = cred->egid;
+ rcu_read_unlock();
+
+ /*
+ * Before the /proc/pid/status file was created the only way to read
+ * the effective uid of a /process was to stat /proc/pid. Reading
+ * /proc/pid/status is slow enough that procps and other packages
+ * kept stating /proc/pid. To keep the rules in /proc simple I have
+ * made this apply to all per process world readable and executable
+ * directories.
+ */
+ if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
+ struct mm_struct *mm;
+ task_lock(task);
+ mm = task->mm;
+ /* Make non-dumpable tasks owned by some root */
+ if (mm) {
+ if (get_dumpable(mm) != SUID_DUMP_USER) {
+ struct user_namespace *user_ns = mm->user_ns;
+
+ uid = make_kuid(user_ns, 0);
+ if (!uid_valid(uid))
+ uid = GLOBAL_ROOT_UID;
+
+ gid = make_kgid(user_ns, 0);
+ if (!gid_valid(gid))
+ gid = GLOBAL_ROOT_GID;
+ }
+ } else {
+ uid = GLOBAL_ROOT_UID;
+ gid = GLOBAL_ROOT_GID;
+ }
+ task_unlock(task);
+ }
+ *ruid = uid;
+ *rgid = gid;
+}
+
+struct inode *proc_pid_make_inode(struct super_block * sb,
+ struct task_struct *task, umode_t mode)
+{
+ struct inode * inode;
+ struct proc_inode *ei;
+
+ /* We need a new inode */
+
+ inode = new_inode(sb);
+ if (!inode)
+ goto out;
+
+ /* Common stuff */
+ ei = PROC_I(inode);
+ inode->i_mode = mode;
+ inode->i_ino = get_next_ino();
+ inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
+ inode->i_op = &proc_def_inode_operations;
+
+ /*
+ * grab the reference to task.
+ */
+ ei->pid = get_task_pid(task, PIDTYPE_PID);
+ if (!ei->pid)
+ goto out_unlock;
+
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
+ security_task_to_inode(task, inode);
+
+out:
+ return inode;
+
+out_unlock:
+ iput(inode);
+ return NULL;
+}
+
+int pid_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ struct inode *inode = d_inode(path->dentry);
+ struct pid_namespace *pid = proc_pid_ns(inode);
+ struct task_struct *task;
+
+ generic_fillattr(inode, stat);
+
+ stat->uid = GLOBAL_ROOT_UID;
+ stat->gid = GLOBAL_ROOT_GID;
+ rcu_read_lock();
+ task = pid_task(proc_pid(inode), PIDTYPE_PID);
+ if (task) {
+ if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
+ rcu_read_unlock();
+ /*
+ * This doesn't prevent learning whether PID exists,
+ * it only makes getattr() consistent with readdir().
+ */
+ return -ENOENT;
+ }
+ task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+/* dentry stuff */
+
+/*
+ * Set <pid>/... inode ownership (can change due to setuid(), etc.)
+ */
+void pid_update_inode(struct task_struct *task, struct inode *inode)
+{
+ task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
+
+ inode->i_mode &= ~(S_ISUID | S_ISGID);
+ security_task_to_inode(task, inode);
+}
+
+/*
+ * Rewrite the inode's ownerships here because the owning task may have
+ * performed a setuid(), etc.
+ *
+ */
+static int pid_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct inode *inode;
+ struct task_struct *task;
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = d_inode(dentry);
+ task = get_proc_task(inode);
+
+ if (task) {
+ pid_update_inode(task, inode);
+ put_task_struct(task);
+ return 1;
+ }
+ return 0;
+}
+
+static inline bool proc_inode_is_dead(struct inode *inode)
+{
+ return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
+}
+
+int pid_delete_dentry(const struct dentry *dentry)
+{
+ /* Is the task we represent dead?
+ * If so, then don't put the dentry on the lru list,
+ * kill it immediately.
+ */
+ return proc_inode_is_dead(d_inode(dentry));
+}
+
+const struct dentry_operations pid_dentry_operations =
+{
+ .d_revalidate = pid_revalidate,
+ .d_delete = pid_delete_dentry,
+};
+
+/* Lookups */
+
+/*
+ * Fill a directory entry.
+ *
+ * If possible create the dcache entry and derive our inode number and
+ * file type from dcache entry.
+ *
+ * Since all of the proc inode numbers are dynamically generated, the inode
+ * numbers do not exist until the inode is cache. This means creating the
+ * the dcache entry in readdir is necessary to keep the inode numbers
+ * reported by readdir in sync with the inode numbers reported
+ * by stat.
+ */
+bool proc_fill_cache(struct file *file, struct dir_context *ctx,
+ const char *name, unsigned int len,
+ instantiate_t instantiate, struct task_struct *task, const void *ptr)
+{
+ struct dentry *child, *dir = file->f_path.dentry;
+ struct qstr qname = QSTR_INIT(name, len);
+ struct inode *inode;
+ unsigned type = DT_UNKNOWN;
+ ino_t ino = 1;
+
+ child = d_hash_and_lookup(dir, &qname);
+ if (!child) {
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ child = d_alloc_parallel(dir, &qname, &wq);
+ if (IS_ERR(child))
+ goto end_instantiate;
+ if (d_in_lookup(child)) {
+ struct dentry *res;
+ res = instantiate(child, task, ptr);
+ d_lookup_done(child);
+ if (unlikely(res)) {
+ dput(child);
+ child = res;
+ if (IS_ERR(child))
+ goto end_instantiate;
+ }
+ }
+ }
+ inode = d_inode(child);
+ ino = inode->i_ino;
+ type = inode->i_mode >> 12;
+ dput(child);
+end_instantiate:
+ return dir_emit(ctx, name, len, ino, type);
+}
+
+/*
+ * dname_to_vma_addr - maps a dentry name into two unsigned longs
+ * which represent vma start and end addresses.
+ */
+static int dname_to_vma_addr(struct dentry *dentry,
+ unsigned long *start, unsigned long *end)
+{
+ const char *str = dentry->d_name.name;
+ unsigned long long sval, eval;
+ unsigned int len;
+
+ if (str[0] == '0' && str[1] != '-')
+ return -EINVAL;
+ len = _parse_integer(str, 16, &sval);
+ if (len & KSTRTOX_OVERFLOW)
+ return -EINVAL;
+ if (sval != (unsigned long)sval)
+ return -EINVAL;
+ str += len;
+
+ if (*str != '-')
+ return -EINVAL;
+ str++;
+
+ if (str[0] == '0' && str[1])
+ return -EINVAL;
+ len = _parse_integer(str, 16, &eval);
+ if (len & KSTRTOX_OVERFLOW)
+ return -EINVAL;
+ if (eval != (unsigned long)eval)
+ return -EINVAL;
+ str += len;
+
+ if (*str != '\0')
+ return -EINVAL;
+
+ *start = sval;
+ *end = eval;
+
+ return 0;
+}
+
+static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ unsigned long vm_start, vm_end;
+ bool exact_vma_exists = false;
+ struct mm_struct *mm = NULL;
+ struct task_struct *task;
+ struct inode *inode;
+ int status = 0;
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = d_inode(dentry);
+ task = get_proc_task(inode);
+ if (!task)
+ goto out_notask;
+
+ mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
+ if (IS_ERR_OR_NULL(mm))
+ goto out;
+
+ if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
+ down_read(&mm->mmap_sem);
+ exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
+ up_read(&mm->mmap_sem);
+ }
+
+ mmput(mm);
+
+ if (exact_vma_exists) {
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
+
+ security_task_to_inode(task, inode);
+ status = 1;
+ }
+
+out:
+ put_task_struct(task);
+
+out_notask:
+ return status;
+}
+
+static const struct dentry_operations tid_map_files_dentry_operations = {
+ .d_revalidate = map_files_d_revalidate,
+ .d_delete = pid_delete_dentry,
+};
+
+static int map_files_get_link(struct dentry *dentry, struct path *path)
+{
+ unsigned long vm_start, vm_end;
+ struct vm_area_struct *vma;
+ struct task_struct *task;
+ struct mm_struct *mm;
+ int rc;
+
+ rc = -ENOENT;
+ task = get_proc_task(d_inode(dentry));
+ if (!task)
+ goto out;
+
+ mm = get_task_mm(task);
+ put_task_struct(task);
+ if (!mm)
+ goto out;
+
+ rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
+ if (rc)
+ goto out_mmput;
+
+ rc = -ENOENT;
+ down_read(&mm->mmap_sem);
+ vma = find_exact_vma(mm, vm_start, vm_end);
+ if (vma && vma->vm_file) {
+ *path = vma->vm_file->f_path;
+ path_get(path);
+ rc = 0;
+ }
+ up_read(&mm->mmap_sem);
+
+out_mmput:
+ mmput(mm);
+out:
+ return rc;
+}
+
+struct map_files_info {
+ unsigned long start;
+ unsigned long end;
+ fmode_t mode;
+};
+
+/*
+ * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
+ * symlinks may be used to bypass permissions on ancestor directories in the
+ * path to the file in question.
+ */
+static const char *
+proc_map_files_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ return proc_pid_get_link(dentry, inode, done);
+}
+
+/*
+ * Identical to proc_pid_link_inode_operations except for get_link()
+ */
+static const struct inode_operations proc_map_files_link_inode_operations = {
+ .readlink = proc_pid_readlink,
+ .get_link = proc_map_files_get_link,
+ .setattr = proc_setattr,
+};
+
+static struct dentry *
+proc_map_files_instantiate(struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
+{
+ fmode_t mode = (fmode_t)(unsigned long)ptr;
+ struct proc_inode *ei;
+ struct inode *inode;
+
+ inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
+ ((mode & FMODE_READ ) ? S_IRUSR : 0) |
+ ((mode & FMODE_WRITE) ? S_IWUSR : 0));
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+
+ ei = PROC_I(inode);
+ ei->op.proc_get_link = map_files_get_link;
+
+ inode->i_op = &proc_map_files_link_inode_operations;
+ inode->i_size = 64;
+
+ d_set_d_op(dentry, &tid_map_files_dentry_operations);
+ return d_splice_alias(inode, dentry);
+}
+
+static struct dentry *proc_map_files_lookup(struct inode *dir,
+ struct dentry *dentry, unsigned int flags)
+{
+ unsigned long vm_start, vm_end;
+ struct vm_area_struct *vma;
+ struct task_struct *task;
+ struct dentry *result;
+ struct mm_struct *mm;
+
+ result = ERR_PTR(-ENOENT);
+ task = get_proc_task(dir);
+ if (!task)
+ goto out;
+
+ result = ERR_PTR(-EACCES);
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
+ goto out_put_task;
+
+ result = ERR_PTR(-ENOENT);
+ if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
+ goto out_put_task;
+
+ mm = get_task_mm(task);
+ if (!mm)
+ goto out_put_task;
+
+ down_read(&mm->mmap_sem);
+ vma = find_exact_vma(mm, vm_start, vm_end);
+ if (!vma)
+ goto out_no_vma;
+
+ if (vma->vm_file)
+ result = proc_map_files_instantiate(dentry, task,
+ (void *)(unsigned long)vma->vm_file->f_mode);
+
+out_no_vma:
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+out_put_task:
+ put_task_struct(task);
+out:
+ return result;
+}
+
+static const struct inode_operations proc_map_files_inode_operations = {
+ .lookup = proc_map_files_lookup,
+ .permission = proc_fd_permission,
+ .setattr = proc_setattr,
+};
+
+static int
+proc_map_files_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct vm_area_struct *vma;
+ struct task_struct *task;
+ struct mm_struct *mm;
+ unsigned long nr_files, pos, i;
+ struct flex_array *fa = NULL;
+ struct map_files_info info;
+ struct map_files_info *p;
+ int ret;
+
+ ret = -ENOENT;
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ goto out;
+
+ ret = -EACCES;
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
+ goto out_put_task;
+
+ ret = 0;
+ if (!dir_emit_dots(file, ctx))
+ goto out_put_task;
+
+ mm = get_task_mm(task);
+ if (!mm)
+ goto out_put_task;
+ down_read(&mm->mmap_sem);
+
+ nr_files = 0;
+
+ /*
+ * We need two passes here:
+ *
+ * 1) Collect vmas of mapped files with mmap_sem taken
+ * 2) Release mmap_sem and instantiate entries
+ *
+ * otherwise we get lockdep complained, since filldir()
+ * routine might require mmap_sem taken in might_fault().
+ */
+
+ for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
+ if (vma->vm_file && ++pos > ctx->pos)
+ nr_files++;
+ }
+
+ if (nr_files) {
+ fa = flex_array_alloc(sizeof(info), nr_files,
+ GFP_KERNEL);
+ if (!fa || flex_array_prealloc(fa, 0, nr_files,
+ GFP_KERNEL)) {
+ ret = -ENOMEM;
+ if (fa)
+ flex_array_free(fa);
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ goto out_put_task;
+ }
+ for (i = 0, vma = mm->mmap, pos = 2; vma;
+ vma = vma->vm_next) {
+ if (!vma->vm_file)
+ continue;
+ if (++pos <= ctx->pos)
+ continue;
+
+ info.start = vma->vm_start;
+ info.end = vma->vm_end;
+ info.mode = vma->vm_file->f_mode;
+ if (flex_array_put(fa, i++, &info, GFP_KERNEL))
+ BUG();
+ }
+ }
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+
+ for (i = 0; i < nr_files; i++) {
+ char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
+ unsigned int len;
+
+ p = flex_array_get(fa, i);
+ len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
+ if (!proc_fill_cache(file, ctx,
+ buf, len,
+ proc_map_files_instantiate,
+ task,
+ (void *)(unsigned long)p->mode))
+ break;
+ ctx->pos++;
+ }
+ if (fa)
+ flex_array_free(fa);
+
+out_put_task:
+ put_task_struct(task);
+out:
+ return ret;
+}
+
+static const struct file_operations proc_map_files_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = proc_map_files_readdir,
+ .llseek = generic_file_llseek,
+};
+
+#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
+struct timers_private {
+ struct pid *pid;
+ struct task_struct *task;
+ struct sighand_struct *sighand;
+ struct pid_namespace *ns;
+ unsigned long flags;
+};
+
+static void *timers_start(struct seq_file *m, loff_t *pos)
+{
+ struct timers_private *tp = m->private;
+
+ tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
+ if (!tp->task)
+ return ERR_PTR(-ESRCH);
+
+ tp->sighand = lock_task_sighand(tp->task, &tp->flags);
+ if (!tp->sighand)
+ return ERR_PTR(-ESRCH);
+
+ return seq_list_start(&tp->task->signal->posix_timers, *pos);
+}
+
+static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct timers_private *tp = m->private;
+ return seq_list_next(v, &tp->task->signal->posix_timers, pos);
+}
+
+static void timers_stop(struct seq_file *m, void *v)
+{
+ struct timers_private *tp = m->private;
+
+ if (tp->sighand) {
+ unlock_task_sighand(tp->task, &tp->flags);
+ tp->sighand = NULL;
+ }
+
+ if (tp->task) {
+ put_task_struct(tp->task);
+ tp->task = NULL;
+ }
+}
+
+static int show_timer(struct seq_file *m, void *v)
+{
+ struct k_itimer *timer;
+ struct timers_private *tp = m->private;
+ int notify;
+ static const char * const nstr[] = {
+ [SIGEV_SIGNAL] = "signal",
+ [SIGEV_NONE] = "none",
+ [SIGEV_THREAD] = "thread",
+ };
+
+ timer = list_entry((struct list_head *)v, struct k_itimer, list);
+ notify = timer->it_sigev_notify;
+
+ seq_printf(m, "ID: %d\n", timer->it_id);
+ seq_printf(m, "signal: %d/%px\n",
+ timer->sigq->info.si_signo,
+ timer->sigq->info.si_value.sival_ptr);
+ seq_printf(m, "notify: %s/%s.%d\n",
+ nstr[notify & ~SIGEV_THREAD_ID],
+ (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
+ pid_nr_ns(timer->it_pid, tp->ns));
+ seq_printf(m, "ClockID: %d\n", timer->it_clock);
+
+ return 0;
+}
+
+static const struct seq_operations proc_timers_seq_ops = {
+ .start = timers_start,
+ .next = timers_next,
+ .stop = timers_stop,
+ .show = show_timer,
+};
+
+static int proc_timers_open(struct inode *inode, struct file *file)
+{
+ struct timers_private *tp;
+
+ tp = __seq_open_private(file, &proc_timers_seq_ops,
+ sizeof(struct timers_private));
+ if (!tp)
+ return -ENOMEM;
+
+ tp->pid = proc_pid(inode);
+ tp->ns = proc_pid_ns(inode);
+ return 0;
+}
+
+static const struct file_operations proc_timers_operations = {
+ .open = proc_timers_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+#endif
+
+static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offset)
+{
+ struct inode *inode = file_inode(file);
+ struct task_struct *p;
+ u64 slack_ns;
+ int err;
+
+ err = kstrtoull_from_user(buf, count, 10, &slack_ns);
+ if (err < 0)
+ return err;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+
+ if (p != current) {
+ if (!capable(CAP_SYS_NICE)) {
+ count = -EPERM;
+ goto out;
+ }
+
+ err = security_task_setscheduler(p);
+ if (err) {
+ count = err;
+ goto out;
+ }
+ }
+
+ task_lock(p);
+ if (slack_ns == 0)
+ p->timer_slack_ns = p->default_timer_slack_ns;
+ else
+ p->timer_slack_ns = slack_ns;
+ task_unlock(p);
+
+out:
+ put_task_struct(p);
+
+ return count;
+}
+
+static int timerslack_ns_show(struct seq_file *m, void *v)
+{
+ struct inode *inode = m->private;
+ struct task_struct *p;
+ int err = 0;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+
+ if (p != current) {
+
+ if (!capable(CAP_SYS_NICE)) {
+ err = -EPERM;
+ goto out;
+ }
+ err = security_task_getscheduler(p);
+ if (err)
+ goto out;
+ }
+
+ task_lock(p);
+ seq_printf(m, "%llu\n", p->timer_slack_ns);
+ task_unlock(p);
+
+out:
+ put_task_struct(p);
+
+ return err;
+}
+
+static int timerslack_ns_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, timerslack_ns_show, inode);
+}
+
+static const struct file_operations proc_pid_set_timerslack_ns_operations = {
+ .open = timerslack_ns_open,
+ .read = seq_read,
+ .write = timerslack_ns_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *proc_pident_instantiate(struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
+{
+ const struct pid_entry *p = ptr;
+ struct inode *inode;
+ struct proc_inode *ei;
+
+ inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+
+ ei = PROC_I(inode);
+ if (S_ISDIR(inode->i_mode))
+ set_nlink(inode, 2); /* Use getattr to fix if necessary */
+ if (p->iop)
+ inode->i_op = p->iop;
+ if (p->fop)
+ inode->i_fop = p->fop;
+ ei->op = p->op;
+ pid_update_inode(task, inode);
+ d_set_d_op(dentry, &pid_dentry_operations);
+ return d_splice_alias(inode, dentry);
+}
+
+static struct dentry *proc_pident_lookup(struct inode *dir,
+ struct dentry *dentry,
+ const struct pid_entry *ents,
+ unsigned int nents)
+{
+ struct task_struct *task = get_proc_task(dir);
+ const struct pid_entry *p, *last;
+ struct dentry *res = ERR_PTR(-ENOENT);
+
+ if (!task)
+ goto out_no_task;
+
+ /*
+ * Yes, it does not scale. And it should not. Don't add
+ * new entries into /proc/<tgid>/ without very good reasons.
+ */
+ last = &ents[nents];
+ for (p = ents; p < last; p++) {
+ if (p->len != dentry->d_name.len)
+ continue;
+ if (!memcmp(dentry->d_name.name, p->name, p->len)) {
+ res = proc_pident_instantiate(dentry, task, p);
+ break;
+ }
+ }
+ put_task_struct(task);
+out_no_task:
+ return res;
+}
+
+static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
+ const struct pid_entry *ents, unsigned int nents)
+{
+ struct task_struct *task = get_proc_task(file_inode(file));
+ const struct pid_entry *p;
+
+ if (!task)
+ return -ENOENT;
+
+ if (!dir_emit_dots(file, ctx))
+ goto out;
+
+ if (ctx->pos >= nents + 2)
+ goto out;
+
+ for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
+ if (!proc_fill_cache(file, ctx, p->name, p->len,
+ proc_pident_instantiate, task, p))
+ break;
+ ctx->pos++;
+ }
+out:
+ put_task_struct(task);
+ return 0;
+}
+
+#ifdef CONFIG_SECURITY
+static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file_inode(file);
+ char *p = NULL;
+ ssize_t length;
+ struct task_struct *task = get_proc_task(inode);
+
+ if (!task)
+ return -ESRCH;
+
+ length = security_getprocattr(task,
+ (char*)file->f_path.dentry->d_name.name,
+ &p);
+ put_task_struct(task);
+ if (length > 0)
+ length = simple_read_from_buffer(buf, count, ppos, p, length);
+ kfree(p);
+ return length;
+}
+
+static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file_inode(file);
+ struct task_struct *task;
+ void *page;
+ int rv;
+
+ rcu_read_lock();
+ task = pid_task(proc_pid(inode), PIDTYPE_PID);
+ if (!task) {
+ rcu_read_unlock();
+ return -ESRCH;
+ }
+ /* A task may only write its own attributes. */
+ if (current != task) {
+ rcu_read_unlock();
+ return -EACCES;
+ }
+ rcu_read_unlock();
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+
+ /* No partial writes. */
+ if (*ppos != 0)
+ return -EINVAL;
+
+ page = memdup_user(buf, count);
+ if (IS_ERR(page)) {
+ rv = PTR_ERR(page);
+ goto out;
+ }
+
+ /* Guard against adverse ptrace interaction */
+ rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
+ if (rv < 0)
+ goto out_free;
+
+ rv = security_setprocattr(file->f_path.dentry->d_name.name, page, count);
+ mutex_unlock(¤t->signal->cred_guard_mutex);
+out_free:
+ kfree(page);
+out:
+ return rv;
+}
+
+static const struct file_operations proc_pid_attr_operations = {
+ .read = proc_pid_attr_read,
+ .write = proc_pid_attr_write,
+ .llseek = generic_file_llseek,
+};
+
+static const struct pid_entry attr_dir_stuff[] = {
+ REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+ REG("prev", S_IRUGO, proc_pid_attr_operations),
+ REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+ REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+ REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+ REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
+};
+
+static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
+{
+ return proc_pident_readdir(file, ctx,
+ attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
+}
+
+static const struct file_operations proc_attr_dir_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = proc_attr_dir_readdir,
+ .llseek = generic_file_llseek,
+};
+
+static struct dentry *proc_attr_dir_lookup(struct inode *dir,
+ struct dentry *dentry, unsigned int flags)
+{
+ return proc_pident_lookup(dir, dentry,
+ attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
+}
+
+static const struct inode_operations proc_attr_dir_inode_operations = {
+ .lookup = proc_attr_dir_lookup,
+ .getattr = pid_getattr,
+ .setattr = proc_setattr,
+};
+
+#endif
+
+#ifdef CONFIG_ELF_CORE
+static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task = get_proc_task(file_inode(file));
+ struct mm_struct *mm;
+ char buffer[PROC_NUMBUF];
+ size_t len;
+ int ret;
+
+ if (!task)
+ return -ESRCH;
+
+ ret = 0;
+ mm = get_task_mm(task);
+ if (mm) {
+ len = snprintf(buffer, sizeof(buffer), "%08lx\n",
+ ((mm->flags & MMF_DUMP_FILTER_MASK) >>
+ MMF_DUMP_FILTER_SHIFT));
+ mmput(mm);
+ ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
+ }
+
+ put_task_struct(task);
+
+ return ret;
+}
+
+static ssize_t proc_coredump_filter_write(struct file *file,
+ const char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ struct task_struct *task;
+ struct mm_struct *mm;
+ unsigned int val;
+ int ret;
+ int i;
+ unsigned long mask;
+
+ ret = kstrtouint_from_user(buf, count, 0, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = -ESRCH;
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ goto out_no_task;
+
+ mm = get_task_mm(task);
+ if (!mm)
+ goto out_no_mm;
+ ret = 0;
+
+ for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
+ if (val & mask)
+ set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
+ else
+ clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
+ }
+
+ mmput(mm);
+ out_no_mm:
+ put_task_struct(task);
+ out_no_task:
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
+static const struct file_operations proc_coredump_filter_operations = {
+ .read = proc_coredump_filter_read,
+ .write = proc_coredump_filter_write,
+ .llseek = generic_file_llseek,
+};
+#endif
+
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
+{
+ struct task_io_accounting acct = task->ioac;
+ unsigned long flags;
+ int result;
+
+ result = mutex_lock_killable(&task->signal->cred_guard_mutex);
+ if (result)
+ return result;
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
+ result = -EACCES;
+ goto out_unlock;
+ }
+
+ if (whole && lock_task_sighand(task, &flags)) {
+ struct task_struct *t = task;
+
+ task_io_accounting_add(&acct, &task->signal->ioac);
+ while_each_thread(task, t)
+ task_io_accounting_add(&acct, &t->ioac);
+
+ unlock_task_sighand(task, &flags);
+ }
+ seq_printf(m,
+ "rchar: %llu\n"
+ "wchar: %llu\n"
+ "syscr: %llu\n"
+ "syscw: %llu\n"
+ "read_bytes: %llu\n"
+ "write_bytes: %llu\n"
+ "cancelled_write_bytes: %llu\n",
+ (unsigned long long)acct.rchar,
+ (unsigned long long)acct.wchar,
+ (unsigned long long)acct.syscr,
+ (unsigned long long)acct.syscw,
+ (unsigned long long)acct.read_bytes,
+ (unsigned long long)acct.write_bytes,
+ (unsigned long long)acct.cancelled_write_bytes);
+ result = 0;
+
+out_unlock:
+ mutex_unlock(&task->signal->cred_guard_mutex);
+ return result;
+}
+
+static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ return do_io_accounting(task, m, 0);
+}
+
+static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ return do_io_accounting(task, m, 1);
+}
+#endif /* CONFIG_TASK_IO_ACCOUNTING */
+
+#ifdef CONFIG_USER_NS
+static int proc_id_map_open(struct inode *inode, struct file *file,
+ const struct seq_operations *seq_ops)
+{
+ struct user_namespace *ns = NULL;
+ struct task_struct *task;
+ struct seq_file *seq;
+ int ret = -EINVAL;
+
+ task = get_proc_task(inode);
+ if (task) {
+ rcu_read_lock();
+ ns = get_user_ns(task_cred_xxx(task, user_ns));
+ rcu_read_unlock();
+ put_task_struct(task);
+ }
+ if (!ns)
+ goto err;
+
+ ret = seq_open(file, seq_ops);
+ if (ret)
+ goto err_put_ns;
+
+ seq = file->private_data;
+ seq->private = ns;
+
+ return 0;
+err_put_ns:
+ put_user_ns(ns);
+err:
+ return ret;
+}
+
+static int proc_id_map_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ struct user_namespace *ns = seq->private;
+ put_user_ns(ns);
+ return seq_release(inode, file);
+}
+
+static int proc_uid_map_open(struct inode *inode, struct file *file)
+{
+ return proc_id_map_open(inode, file, &proc_uid_seq_operations);
+}
+
+static int proc_gid_map_open(struct inode *inode, struct file *file)
+{
+ return proc_id_map_open(inode, file, &proc_gid_seq_operations);
+}
+
+static int proc_projid_map_open(struct inode *inode, struct file *file)
+{
+ return proc_id_map_open(inode, file, &proc_projid_seq_operations);
+}
+
+static const struct file_operations proc_uid_map_operations = {
+ .open = proc_uid_map_open,
+ .write = proc_uid_map_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = proc_id_map_release,
+};
+
+static const struct file_operations proc_gid_map_operations = {
+ .open = proc_gid_map_open,
+ .write = proc_gid_map_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = proc_id_map_release,
+};
+
+static const struct file_operations proc_projid_map_operations = {
+ .open = proc_projid_map_open,
+ .write = proc_projid_map_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = proc_id_map_release,
+};
+
+static int proc_setgroups_open(struct inode *inode, struct file *file)
+{
+ struct user_namespace *ns = NULL;
+ struct task_struct *task;
+ int ret;
+
+ ret = -ESRCH;
+ task = get_proc_task(inode);
+ if (task) {
+ rcu_read_lock();
+ ns = get_user_ns(task_cred_xxx(task, user_ns));
+ rcu_read_unlock();
+ put_task_struct(task);
+ }
+ if (!ns)
+ goto err;
+
+ if (file->f_mode & FMODE_WRITE) {
+ ret = -EACCES;
+ if (!ns_capable(ns, CAP_SYS_ADMIN))
+ goto err_put_ns;
+ }
+
+ ret = single_open(file, &proc_setgroups_show, ns);
+ if (ret)
+ goto err_put_ns;
+
+ return 0;
+err_put_ns:
+ put_user_ns(ns);
+err:
+ return ret;
+}
+
+static int proc_setgroups_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ struct user_namespace *ns = seq->private;
+ int ret = single_release(inode, file);
+ put_user_ns(ns);
+ return ret;
+}
+
+static const struct file_operations proc_setgroups_operations = {
+ .open = proc_setgroups_open,
+ .write = proc_setgroups_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = proc_setgroups_release,
+};
+#endif /* CONFIG_USER_NS */
+
+static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ int err = lock_trace(task);
+ if (!err) {
+ seq_printf(m, "%08x\n", task->personality);
+ unlock_trace(task);
+ }
+ return err;
+}
+
+#ifdef CONFIG_LIVEPATCH
+static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ seq_printf(m, "%d\n", task->patch_state);
+ return 0;
+}
+#endif /* CONFIG_LIVEPATCH */
+
+/*
+ * Thread groups
+ */
+static const struct file_operations proc_task_operations;
+static const struct inode_operations proc_task_inode_operations;
+
+static const struct pid_entry tgid_base_stuff[] = {
+ DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
+ DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
+ DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
+ DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
+ DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
+#ifdef CONFIG_NET
+ DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
+#endif
+ REG("environ", S_IRUSR, proc_environ_operations),
+ REG("auxv", S_IRUSR, proc_auxv_operations),
+ ONE("status", S_IRUGO, proc_pid_status),
+ ONE("personality", S_IRUSR, proc_pid_personality),
+ ONE("limits", S_IRUGO, proc_pid_limits),
+#ifdef CONFIG_SCHED_DEBUG
+ REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
+#endif
+#ifdef CONFIG_SCHED_AUTOGROUP
+ REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
+#endif
+ REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+ ONE("syscall", S_IRUSR, proc_pid_syscall),
+#endif
+ REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
+ ONE("stat", S_IRUGO, proc_tgid_stat),
+ ONE("statm", S_IRUGO, proc_pid_statm),
+ REG("maps", S_IRUGO, proc_pid_maps_operations),
+#ifdef CONFIG_NUMA
+ REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
+#endif
+ REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
+ LNK("cwd", proc_cwd_link),
+ LNK("root", proc_root_link),
+ LNK("exe", proc_exe_link),
+ REG("mounts", S_IRUGO, proc_mounts_operations),
+ REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
+ REG("mountstats", S_IRUSR, proc_mountstats_operations),
+#ifdef CONFIG_PROC_PAGE_MONITOR
+ REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
+ REG("smaps", S_IRUGO, proc_pid_smaps_operations),
+ REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
+ REG("pagemap", S_IRUSR, proc_pagemap_operations),
+#endif
+#ifdef CONFIG_SECURITY
+ DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
+#endif
+#ifdef CONFIG_KALLSYMS
+ ONE("wchan", S_IRUGO, proc_pid_wchan),
+#endif
+#ifdef CONFIG_STACKTRACE
+ ONE("stack", S_IRUSR, proc_pid_stack),
+#endif
+#ifdef CONFIG_SCHED_INFO
+ ONE("schedstat", S_IRUGO, proc_pid_schedstat),
+#endif
+#ifdef CONFIG_LATENCYTOP
+ REG("latency", S_IRUGO, proc_lstats_operations),
+#endif
+#ifdef CONFIG_PROC_PID_CPUSET
+ ONE("cpuset", S_IRUGO, proc_cpuset_show),
+#endif
+#ifdef CONFIG_CGROUPS
+ ONE("cgroup", S_IRUGO, proc_cgroup_show),
+#endif
+ ONE("oom_score", S_IRUGO, proc_oom_score),
+ REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
+ REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
+#ifdef CONFIG_AUDITSYSCALL
+ REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
+ REG("sessionid", S_IRUGO, proc_sessionid_operations),
+#endif
+#ifdef CONFIG_FAULT_INJECTION
+ REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+ REG("fail-nth", 0644, proc_fail_nth_operations),
+#endif
+#ifdef CONFIG_ELF_CORE
+ REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
+#endif
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+ ONE("io", S_IRUSR, proc_tgid_io_accounting),
+#endif
+#ifdef CONFIG_USER_NS
+ REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
+ REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
+ REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
+ REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
+#endif
+#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
+ REG("timers", S_IRUGO, proc_timers_operations),
+#endif
+ REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
+#ifdef CONFIG_LIVEPATCH
+ ONE("patch_state", S_IRUSR, proc_pid_patch_state),
+#endif
+};
+
+static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
+{
+ return proc_pident_readdir(file, ctx,
+ tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
+}
+
+static const struct file_operations proc_tgid_base_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = proc_tgid_base_readdir,
+ .llseek = generic_file_llseek,
+};
+
+static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+ return proc_pident_lookup(dir, dentry,
+ tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
+}
+
+static const struct inode_operations proc_tgid_base_inode_operations = {
+ .lookup = proc_tgid_base_lookup,
+ .getattr = pid_getattr,
+ .setattr = proc_setattr,
+ .permission = proc_pid_permission,
+};
+
+static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
+{
+ struct dentry *dentry, *leader, *dir;
+ char buf[10 + 1];
+ struct qstr name;
+
+ name.name = buf;
+ name.len = snprintf(buf, sizeof(buf), "%u", pid);
+ /* no ->d_hash() rejects on procfs */
+ dentry = d_hash_and_lookup(mnt->mnt_root, &name);
+ if (dentry) {
+ d_invalidate(dentry);
+ dput(dentry);
+ }
+
+ if (pid == tgid)
+ return;
+
+ name.name = buf;
+ name.len = snprintf(buf, sizeof(buf), "%u", tgid);
+ leader = d_hash_and_lookup(mnt->mnt_root, &name);
+ if (!leader)
+ goto out;
+
+ name.name = "task";
+ name.len = strlen(name.name);
+ dir = d_hash_and_lookup(leader, &name);
+ if (!dir)
+ goto out_put_leader;
+
+ name.name = buf;
+ name.len = snprintf(buf, sizeof(buf), "%u", pid);
+ dentry = d_hash_and_lookup(dir, &name);
+ if (dentry) {
+ d_invalidate(dentry);
+ dput(dentry);
+ }
+
+ dput(dir);
+out_put_leader:
+ dput(leader);
+out:
+ return;
+}
+
+/**
+ * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
+ * @task: task that should be flushed.
+ *
+ * When flushing dentries from proc, one needs to flush them from global
+ * proc (proc_mnt) and from all the namespaces' procs this task was seen
+ * in. This call is supposed to do all of this job.
+ *
+ * Looks in the dcache for
+ * /proc/@pid
+ * /proc/@tgid/task/@pid
+ * if either directory is present flushes it and all of it'ts children
+ * from the dcache.
+ *
+ * It is safe and reasonable to cache /proc entries for a task until
+ * that task exits. After that they just clog up the dcache with
+ * useless entries, possibly causing useful dcache entries to be
+ * flushed instead. This routine is proved to flush those useless
+ * dcache entries at process exit time.
+ *
+ * NOTE: This routine is just an optimization so it does not guarantee
+ * that no dcache entries will exist at process exit time it
+ * just makes it very unlikely that any will persist.
+ */
+
+void proc_flush_task(struct task_struct *task)
+{
+ int i;
+ struct pid *pid, *tgid;
+ struct upid *upid;
+
+ pid = task_pid(task);
+ tgid = task_tgid(task);
+
+ for (i = 0; i <= pid->level; i++) {
+ upid = &pid->numbers[i];
+ proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
+ tgid->numbers[i].nr);
+ }
+}
+
+static struct dentry *proc_pid_instantiate(struct dentry * dentry,
+ struct task_struct *task, const void *ptr)
+{
+ struct inode *inode;
+
+ inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+
+ inode->i_op = &proc_tgid_base_inode_operations;
+ inode->i_fop = &proc_tgid_base_operations;
+ inode->i_flags|=S_IMMUTABLE;
+
+ set_nlink(inode, nlink_tgid);
+ pid_update_inode(task, inode);
+
+ d_set_d_op(dentry, &pid_dentry_operations);
+ return d_splice_alias(inode, dentry);
+}
+
+struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
+{
+ struct task_struct *task;
+ unsigned tgid;
+ struct pid_namespace *ns;
+ struct dentry *result = ERR_PTR(-ENOENT);
+
+ tgid = name_to_int(&dentry->d_name);
+ if (tgid == ~0U)
+ goto out;
+
+ ns = dentry->d_sb->s_fs_info;
+ rcu_read_lock();
+ task = find_task_by_pid_ns(tgid, ns);
+ if (task)
+ get_task_struct(task);
+ rcu_read_unlock();
+ if (!task)
+ goto out;
+
+ result = proc_pid_instantiate(dentry, task, NULL);
+ put_task_struct(task);
+out:
+ return result;
+}
+
+/*
+ * Find the first task with tgid >= tgid
+ *
+ */
+struct tgid_iter {
+ unsigned int tgid;
+ struct task_struct *task;
+};
+static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
+{
+ struct pid *pid;
+
+ if (iter.task)
+ put_task_struct(iter.task);
+ rcu_read_lock();
+retry:
+ iter.task = NULL;
+ pid = find_ge_pid(iter.tgid, ns);
+ if (pid) {
+ iter.tgid = pid_nr_ns(pid, ns);
+ iter.task = pid_task(pid, PIDTYPE_PID);
+ /* What we to know is if the pid we have find is the
+ * pid of a thread_group_leader. Testing for task
+ * being a thread_group_leader is the obvious thing
+ * todo but there is a window when it fails, due to
+ * the pid transfer logic in de_thread.
+ *
+ * So we perform the straight forward test of seeing
+ * if the pid we have found is the pid of a thread
+ * group leader, and don't worry if the task we have
+ * found doesn't happen to be a thread group leader.
+ * As we don't care in the case of readdir.
+ */
+ if (!iter.task || !has_group_leader_pid(iter.task)) {
+ iter.tgid += 1;
+ goto retry;
+ }
+ get_task_struct(iter.task);
+ }
+ rcu_read_unlock();
+ return iter;
+}
+
+#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
+
+/* for the /proc/ directory itself, after non-process stuff has been done */
+int proc_pid_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct tgid_iter iter;
+ struct pid_namespace *ns = proc_pid_ns(file_inode(file));
+ loff_t pos = ctx->pos;
+
+ if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
+ return 0;
+
+ if (pos == TGID_OFFSET - 2) {
+ struct inode *inode = d_inode(ns->proc_self);
+ if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
+ return 0;
+ ctx->pos = pos = pos + 1;
+ }
+ if (pos == TGID_OFFSET - 1) {
+ struct inode *inode = d_inode(ns->proc_thread_self);
+ if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
+ return 0;
+ ctx->pos = pos = pos + 1;
+ }
+ iter.tgid = pos - TGID_OFFSET;
+ iter.task = NULL;
+ for (iter = next_tgid(ns, iter);
+ iter.task;
+ iter.tgid += 1, iter = next_tgid(ns, iter)) {
+ char name[10 + 1];
+ unsigned int len;
+
+ cond_resched();
+ if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
+ continue;
+
+ len = snprintf(name, sizeof(name), "%u", iter.tgid);
+ ctx->pos = iter.tgid + TGID_OFFSET;
+ if (!proc_fill_cache(file, ctx, name, len,
+ proc_pid_instantiate, iter.task, NULL)) {
+ put_task_struct(iter.task);
+ return 0;
+ }
+ }
+ ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
+ return 0;
+}
+
+/*
+ * proc_tid_comm_permission is a special permission function exclusively
+ * used for the node /proc/<pid>/task/<tid>/comm.
+ * It bypasses generic permission checks in the case where a task of the same
+ * task group attempts to access the node.
+ * The rationale behind this is that glibc and bionic access this node for
+ * cross thread naming (pthread_set/getname_np(!self)). However, if
+ * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
+ * which locks out the cross thread naming implementation.
+ * This function makes sure that the node is always accessible for members of
+ * same thread group.
+ */
+static int proc_tid_comm_permission(struct inode *inode, int mask)
+{
+ bool is_same_tgroup;
+ struct task_struct *task;
+
+ task = get_proc_task(inode);
+ if (!task)
+ return -ESRCH;
+ is_same_tgroup = same_thread_group(current, task);
+ put_task_struct(task);
+
+ if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
+ /* This file (/proc/<pid>/task/<tid>/comm) can always be
+ * read or written by the members of the corresponding
+ * thread group.
+ */
+ return 0;
+ }
+
+ return generic_permission(inode, mask);
+}
+
+static const struct inode_operations proc_tid_comm_inode_operations = {
+ .permission = proc_tid_comm_permission,
+};
+
+/*
+ * Tasks
+ */
+static const struct pid_entry tid_base_stuff[] = {
+ DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
+ DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
+ DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
+#ifdef CONFIG_NET
+ DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
+#endif
+ REG("environ", S_IRUSR, proc_environ_operations),
+ REG("auxv", S_IRUSR, proc_auxv_operations),
+ ONE("status", S_IRUGO, proc_pid_status),
+ ONE("personality", S_IRUSR, proc_pid_personality),
+ ONE("limits", S_IRUGO, proc_pid_limits),
+#ifdef CONFIG_SCHED_DEBUG
+ REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
+#endif
+ NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
+ &proc_tid_comm_inode_operations,
+ &proc_pid_set_comm_operations, {}),
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+ ONE("syscall", S_IRUSR, proc_pid_syscall),
+#endif
+ REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
+ ONE("stat", S_IRUGO, proc_tid_stat),
+ ONE("statm", S_IRUGO, proc_pid_statm),
+ REG("maps", S_IRUGO, proc_pid_maps_operations),
+#ifdef CONFIG_PROC_CHILDREN
+ REG("children", S_IRUGO, proc_tid_children_operations),
+#endif
+#ifdef CONFIG_NUMA
+ REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
+#endif
+ REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
+ LNK("cwd", proc_cwd_link),
+ LNK("root", proc_root_link),
+ LNK("exe", proc_exe_link),
+ REG("mounts", S_IRUGO, proc_mounts_operations),
+ REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
+#ifdef CONFIG_PROC_PAGE_MONITOR
+ REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
+ REG("smaps", S_IRUGO, proc_pid_smaps_operations),
+ REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
+ REG("pagemap", S_IRUSR, proc_pagemap_operations),
+#endif
+#ifdef CONFIG_SECURITY
+ DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
+#endif
+#ifdef CONFIG_KALLSYMS
+ ONE("wchan", S_IRUGO, proc_pid_wchan),
+#endif
+#ifdef CONFIG_STACKTRACE
+ ONE("stack", S_IRUSR, proc_pid_stack),
+#endif
+#ifdef CONFIG_SCHED_INFO
+ ONE("schedstat", S_IRUGO, proc_pid_schedstat),
+#endif
+#ifdef CONFIG_LATENCYTOP
+ REG("latency", S_IRUGO, proc_lstats_operations),
+#endif
+#ifdef CONFIG_PROC_PID_CPUSET
+ ONE("cpuset", S_IRUGO, proc_cpuset_show),
+#endif
+#ifdef CONFIG_CGROUPS
+ ONE("cgroup", S_IRUGO, proc_cgroup_show),
+#endif
+ ONE("oom_score", S_IRUGO, proc_oom_score),
+ REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
+ REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
+#ifdef CONFIG_AUDITSYSCALL
+ REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
+ REG("sessionid", S_IRUGO, proc_sessionid_operations),
+#endif
+#ifdef CONFIG_FAULT_INJECTION
+ REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+ REG("fail-nth", 0644, proc_fail_nth_operations),
+#endif
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+ ONE("io", S_IRUSR, proc_tid_io_accounting),
+#endif
+#ifdef CONFIG_USER_NS
+ REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
+ REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
+ REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
+ REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
+#endif
+#ifdef CONFIG_LIVEPATCH
+ ONE("patch_state", S_IRUSR, proc_pid_patch_state),
+#endif
+};
+
+static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
+{
+ return proc_pident_readdir(file, ctx,
+ tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
+}
+
+static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+ return proc_pident_lookup(dir, dentry,
+ tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
+}
+
+static const struct file_operations proc_tid_base_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = proc_tid_base_readdir,
+ .llseek = generic_file_llseek,
+};
+
+static const struct inode_operations proc_tid_base_inode_operations = {
+ .lookup = proc_tid_base_lookup,
+ .getattr = pid_getattr,
+ .setattr = proc_setattr,
+};
+
+static struct dentry *proc_task_instantiate(struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
+{
+ struct inode *inode;
+ inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+
+ inode->i_op = &proc_tid_base_inode_operations;
+ inode->i_fop = &proc_tid_base_operations;
+ inode->i_flags |= S_IMMUTABLE;
+
+ set_nlink(inode, nlink_tid);
+ pid_update_inode(task, inode);
+
+ d_set_d_op(dentry, &pid_dentry_operations);
+ return d_splice_alias(inode, dentry);
+}
+
+static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
+{
+ struct task_struct *task;
+ struct task_struct *leader = get_proc_task(dir);
+ unsigned tid;
+ struct pid_namespace *ns;
+ struct dentry *result = ERR_PTR(-ENOENT);
+
+ if (!leader)
+ goto out_no_task;
+
+ tid = name_to_int(&dentry->d_name);
+ if (tid == ~0U)
+ goto out;
+
+ ns = dentry->d_sb->s_fs_info;
+ rcu_read_lock();
+ task = find_task_by_pid_ns(tid, ns);
+ if (task)
+ get_task_struct(task);
+ rcu_read_unlock();
+ if (!task)
+ goto out;
+ if (!same_thread_group(leader, task))
+ goto out_drop_task;
+
+ result = proc_task_instantiate(dentry, task, NULL);
+out_drop_task:
+ put_task_struct(task);
+out:
+ put_task_struct(leader);
+out_no_task:
+ return result;
+}
+
+/*
+ * Find the first tid of a thread group to return to user space.
+ *
+ * Usually this is just the thread group leader, but if the users
+ * buffer was too small or there was a seek into the middle of the
+ * directory we have more work todo.
+ *
+ * In the case of a short read we start with find_task_by_pid.
+ *
+ * In the case of a seek we start with the leader and walk nr
+ * threads past it.
+ */
+static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
+ struct pid_namespace *ns)
+{
+ struct task_struct *pos, *task;
+ unsigned long nr = f_pos;
+
+ if (nr != f_pos) /* 32bit overflow? */
+ return NULL;
+
+ rcu_read_lock();
+ task = pid_task(pid, PIDTYPE_PID);
+ if (!task)
+ goto fail;
+
+ /* Attempt to start with the tid of a thread */
+ if (tid && nr) {
+ pos = find_task_by_pid_ns(tid, ns);
+ if (pos && same_thread_group(pos, task))
+ goto found;
+ }
+
+ /* If nr exceeds the number of threads there is nothing todo */
+ if (nr >= get_nr_threads(task))
+ goto fail;
+
+ /* If we haven't found our starting place yet start
+ * with the leader and walk nr threads forward.
+ */
+ pos = task = task->group_leader;
+ do {
+ if (!nr--)
+ goto found;
+ } while_each_thread(task, pos);
+fail:
+ pos = NULL;
+ goto out;
+found:
+ get_task_struct(pos);
+out:
+ rcu_read_unlock();
+ return pos;
+}
+
+/*
+ * Find the next thread in the thread list.
+ * Return NULL if there is an error or no next thread.
+ *
+ * The reference to the input task_struct is released.
+ */
+static struct task_struct *next_tid(struct task_struct *start)
+{
+ struct task_struct *pos = NULL;
+ rcu_read_lock();
+ if (pid_alive(start)) {
+ pos = next_thread(start);
+ if (thread_group_leader(pos))
+ pos = NULL;
+ else
+ get_task_struct(pos);
+ }
+ rcu_read_unlock();
+ put_task_struct(start);
+ return pos;
+}
+
+/* for the /proc/TGID/task/ directories */
+static int proc_task_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct inode *inode = file_inode(file);
+ struct task_struct *task;
+ struct pid_namespace *ns;
+ int tid;
+
+ if (proc_inode_is_dead(inode))
+ return -ENOENT;
+
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+
+ /* f_version caches the tgid value that the last readdir call couldn't
+ * return. lseek aka telldir automagically resets f_version to 0.
+ */
+ ns = proc_pid_ns(inode);
+ tid = (int)file->f_version;
+ file->f_version = 0;
+ for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
+ task;
+ task = next_tid(task), ctx->pos++) {
+ char name[10 + 1];
+ unsigned int len;
+ tid = task_pid_nr_ns(task, ns);
+ len = snprintf(name, sizeof(name), "%u", tid);
+ if (!proc_fill_cache(file, ctx, name, len,
+ proc_task_instantiate, task, NULL)) {
+ /* returning this tgid failed, save it as the first
+ * pid for the next readir call */
+ file->f_version = (u64)tid;
+ put_task_struct(task);
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int proc_task_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ struct inode *inode = d_inode(path->dentry);
+ struct task_struct *p = get_proc_task(inode);
+ generic_fillattr(inode, stat);
+
+ if (p) {
+ stat->nlink += get_nr_threads(p);
+ put_task_struct(p);
+ }
+
+ return 0;
+}
+
+static const struct inode_operations proc_task_inode_operations = {
+ .lookup = proc_task_lookup,
+ .getattr = proc_task_getattr,
+ .setattr = proc_setattr,
+ .permission = proc_pid_permission,
+};
+
+static const struct file_operations proc_task_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = proc_task_readdir,
+ .llseek = generic_file_llseek,
+};
+
+void __init set_proc_pid_nlink(void)
+{
+ nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
+ nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
+}