Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 51063e7..7f83f41 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
#include "cgroup-internal.h"
#include <linux/ctype.h>
@@ -13,9 +14,12 @@
#include <linux/delayacct.h>
#include <linux/pid_namespace.h>
#include <linux/cgroupstats.h>
+#include <linux/fs_parser.h>
#include <trace/events/cgroup.h>
+#define cg_invalf(fc, fmt, ...) invalf(fc, fmt, ## __VA_ARGS__)
+
/*
* pidlists linger the following amount before being destroyed. The goal
* is avoiding frequent destruction in the middle of consecutive read calls
@@ -27,6 +31,9 @@
/* Controllers blocked by the commandline in v1 */
static u16 cgroup_no_v1_mask;
+/* disable named v1 mounts */
+static bool cgroup_no_v1_named;
+
/*
* pidlist destructions need to be flushed on cgroup destruction. Use a
* separate workqueue as flush domain.
@@ -187,25 +194,6 @@
};
/*
- * The following two functions "fix" the issue where there are more pids
- * than kmalloc will give memory for; in such cases, we use vmalloc/vfree.
- * TODO: replace with a kernel-wide solution to this problem
- */
-#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
-static void *pidlist_allocate(int count)
-{
- if (PIDLIST_TOO_LARGE(count))
- return vmalloc(array_size(count, sizeof(pid_t)));
- else
- return kmalloc_array(count, sizeof(pid_t), GFP_KERNEL);
-}
-
-static void pidlist_free(void *p)
-{
- kvfree(p);
-}
-
-/*
* Used to destroy all pidlists lingering waiting for destroy timer. None
* should be left afterwards.
*/
@@ -237,7 +225,7 @@
*/
if (!delayed_work_pending(dwork)) {
list_del(&l->links);
- pidlist_free(l->list);
+ kvfree(l->list);
put_pid_ns(l->key.ns);
tofree = l;
}
@@ -336,22 +324,6 @@
return l;
}
-/**
- * cgroup_task_count - count the number of tasks in a cgroup.
- * @cgrp: the cgroup in question
- */
-int cgroup_task_count(const struct cgroup *cgrp)
-{
- int count = 0;
- struct cgrp_cset_link *link;
-
- spin_lock_irq(&css_set_lock);
- list_for_each_entry(link, &cgrp->cset_links, cset_link)
- count += link->cset->nr_tasks;
- spin_unlock_irq(&css_set_lock);
- return count;
-}
-
/*
* Load a cgroup's pidarray with either procs' tgids or tasks' pids
*/
@@ -374,7 +346,7 @@
* show up until sometime later on.
*/
length = cgroup_task_count(cgrp);
- array = pidlist_allocate(length);
+ array = kvmalloc_array(length, sizeof(pid_t), GFP_KERNEL);
if (!array)
return -ENOMEM;
/* now, populate the array */
@@ -399,12 +371,12 @@
l = cgroup_pidlist_find_create(cgrp, type);
if (!l) {
- pidlist_free(array);
+ kvfree(array);
return -ENOMEM;
}
/* store array, freeing old if necessary */
- pidlist_free(l->list);
+ kvfree(l->list);
l->list = array;
l->length = length;
*lp = l;
@@ -903,168 +875,195 @@
return 0;
}
-static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
+enum cgroup1_param {
+ Opt_all,
+ Opt_clone_children,
+ Opt_cpuset_v2_mode,
+ Opt_name,
+ Opt_none,
+ Opt_noprefix,
+ Opt_release_agent,
+ Opt_xattr,
+};
+
+static const struct fs_parameter_spec cgroup1_param_specs[] = {
+ fsparam_flag ("all", Opt_all),
+ fsparam_flag ("clone_children", Opt_clone_children),
+ fsparam_flag ("cpuset_v2_mode", Opt_cpuset_v2_mode),
+ fsparam_string("name", Opt_name),
+ fsparam_flag ("none", Opt_none),
+ fsparam_flag ("noprefix", Opt_noprefix),
+ fsparam_string("release_agent", Opt_release_agent),
+ fsparam_flag ("xattr", Opt_xattr),
+ {}
+};
+
+const struct fs_parameter_description cgroup1_fs_parameters = {
+ .name = "cgroup1",
+ .specs = cgroup1_param_specs,
+};
+
+int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- char *token, *o = data;
- bool all_ss = false, one_ss = false;
- u16 mask = U16_MAX;
+ struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
struct cgroup_subsys *ss;
- int nr_opts = 0;
+ struct fs_parse_result result;
+ int opt, i;
+
+ opt = fs_parse(fc, &cgroup1_fs_parameters, param, &result);
+ if (opt == -ENOPARAM) {
+ if (strcmp(param->key, "source") == 0) {
+ fc->source = param->string;
+ param->string = NULL;
+ return 0;
+ }
+ for_each_subsys(ss, i) {
+ if (strcmp(param->key, ss->legacy_name))
+ continue;
+ ctx->subsys_mask |= (1 << i);
+ return 0;
+ }
+ return cg_invalf(fc, "cgroup1: Unknown subsys name '%s'", param->key);
+ }
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_none:
+ /* Explicitly have no subsystems */
+ ctx->none = true;
+ break;
+ case Opt_all:
+ ctx->all_ss = true;
+ break;
+ case Opt_noprefix:
+ ctx->flags |= CGRP_ROOT_NOPREFIX;
+ break;
+ case Opt_clone_children:
+ ctx->cpuset_clone_children = true;
+ break;
+ case Opt_cpuset_v2_mode:
+ ctx->flags |= CGRP_ROOT_CPUSET_V2_MODE;
+ break;
+ case Opt_xattr:
+ ctx->flags |= CGRP_ROOT_XATTR;
+ break;
+ case Opt_release_agent:
+ /* Specifying two release agents is forbidden */
+ if (ctx->release_agent)
+ return cg_invalf(fc, "cgroup1: release_agent respecified");
+ ctx->release_agent = param->string;
+ param->string = NULL;
+ break;
+ case Opt_name:
+ /* blocked by boot param? */
+ if (cgroup_no_v1_named)
+ return -ENOENT;
+ /* Can't specify an empty name */
+ if (!param->size)
+ return cg_invalf(fc, "cgroup1: Empty name");
+ if (param->size > MAX_CGROUP_ROOT_NAMELEN - 1)
+ return cg_invalf(fc, "cgroup1: Name too long");
+ /* Must match [\w.-]+ */
+ for (i = 0; i < param->size; i++) {
+ char c = param->string[i];
+ if (isalnum(c))
+ continue;
+ if ((c == '.') || (c == '-') || (c == '_'))
+ continue;
+ return cg_invalf(fc, "cgroup1: Invalid name");
+ }
+ /* Specifying two names is forbidden */
+ if (ctx->name)
+ return cg_invalf(fc, "cgroup1: name respecified");
+ ctx->name = param->string;
+ param->string = NULL;
+ break;
+ }
+ return 0;
+}
+
+static int check_cgroupfs_options(struct fs_context *fc)
+{
+ struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
+ u16 mask = U16_MAX;
+ u16 enabled = 0;
+ struct cgroup_subsys *ss;
int i;
#ifdef CONFIG_CPUSETS
mask = ~((u16)1 << cpuset_cgrp_id);
#endif
+ for_each_subsys(ss, i)
+ if (cgroup_ssid_enabled(i) && !cgroup1_ssid_disabled(i))
+ enabled |= 1 << i;
- memset(opts, 0, sizeof(*opts));
-
- while ((token = strsep(&o, ",")) != NULL) {
- nr_opts++;
-
- if (!*token)
- return -EINVAL;
- if (!strcmp(token, "none")) {
- /* Explicitly have no subsystems */
- opts->none = true;
- continue;
- }
- if (!strcmp(token, "all")) {
- /* Mutually exclusive option 'all' + subsystem name */
- if (one_ss)
- return -EINVAL;
- all_ss = true;
- continue;
- }
- if (!strcmp(token, "noprefix")) {
- opts->flags |= CGRP_ROOT_NOPREFIX;
- continue;
- }
- if (!strcmp(token, "clone_children")) {
- opts->cpuset_clone_children = true;
- continue;
- }
- if (!strcmp(token, "cpuset_v2_mode")) {
- opts->flags |= CGRP_ROOT_CPUSET_V2_MODE;
- continue;
- }
- if (!strcmp(token, "xattr")) {
- opts->flags |= CGRP_ROOT_XATTR;
- continue;
- }
- if (!strncmp(token, "release_agent=", 14)) {
- /* Specifying two release agents is forbidden */
- if (opts->release_agent)
- return -EINVAL;
- opts->release_agent =
- kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
- if (!opts->release_agent)
- return -ENOMEM;
- continue;
- }
- if (!strncmp(token, "name=", 5)) {
- const char *name = token + 5;
- /* Can't specify an empty name */
- if (!strlen(name))
- return -EINVAL;
- /* Must match [\w.-]+ */
- for (i = 0; i < strlen(name); i++) {
- char c = name[i];
- if (isalnum(c))
- continue;
- if ((c == '.') || (c == '-') || (c == '_'))
- continue;
- return -EINVAL;
- }
- /* Specifying two names is forbidden */
- if (opts->name)
- return -EINVAL;
- opts->name = kstrndup(name,
- MAX_CGROUP_ROOT_NAMELEN - 1,
- GFP_KERNEL);
- if (!opts->name)
- return -ENOMEM;
-
- continue;
- }
-
- for_each_subsys(ss, i) {
- if (strcmp(token, ss->legacy_name))
- continue;
- if (!cgroup_ssid_enabled(i))
- continue;
- if (cgroup1_ssid_disabled(i))
- continue;
-
- /* Mutually exclusive option 'all' + subsystem name */
- if (all_ss)
- return -EINVAL;
- opts->subsys_mask |= (1 << i);
- one_ss = true;
-
- break;
- }
- if (i == CGROUP_SUBSYS_COUNT)
- return -ENOENT;
- }
+ ctx->subsys_mask &= enabled;
/*
- * If the 'all' option was specified select all the subsystems,
- * otherwise if 'none', 'name=' and a subsystem name options were
- * not specified, let's default to 'all'
+ * In absense of 'none', 'name=' or subsystem name options,
+ * let's default to 'all'.
*/
- if (all_ss || (!one_ss && !opts->none && !opts->name))
- for_each_subsys(ss, i)
- if (cgroup_ssid_enabled(i) && !cgroup1_ssid_disabled(i))
- opts->subsys_mask |= (1 << i);
+ if (!ctx->subsys_mask && !ctx->none && !ctx->name)
+ ctx->all_ss = true;
+
+ if (ctx->all_ss) {
+ /* Mutually exclusive option 'all' + subsystem name */
+ if (ctx->subsys_mask)
+ return cg_invalf(fc, "cgroup1: subsys name conflicts with all");
+ /* 'all' => select all the subsystems */
+ ctx->subsys_mask = enabled;
+ }
/*
* We either have to specify by name or by subsystems. (So all
* empty hierarchies must have a name).
*/
- if (!opts->subsys_mask && !opts->name)
- return -EINVAL;
+ if (!ctx->subsys_mask && !ctx->name)
+ return cg_invalf(fc, "cgroup1: Need name or subsystem set");
/*
* Option noprefix was introduced just for backward compatibility
* with the old cpuset, so we allow noprefix only if mounting just
* the cpuset subsystem.
*/
- if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
- return -EINVAL;
+ if ((ctx->flags & CGRP_ROOT_NOPREFIX) && (ctx->subsys_mask & mask))
+ return cg_invalf(fc, "cgroup1: noprefix used incorrectly");
/* Can't specify "none" and some subsystems */
- if (opts->subsys_mask && opts->none)
- return -EINVAL;
+ if (ctx->subsys_mask && ctx->none)
+ return cg_invalf(fc, "cgroup1: none used incorrectly");
return 0;
}
-static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)
+int cgroup1_reconfigure(struct fs_context *fc)
{
- int ret = 0;
+ struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
+ struct kernfs_root *kf_root = kernfs_root_from_sb(fc->root->d_sb);
struct cgroup_root *root = cgroup_root_from_kf(kf_root);
- struct cgroup_sb_opts opts;
+ int ret = 0;
u16 added_mask, removed_mask;
cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
/* See what subsystems are wanted */
- ret = parse_cgroupfs_options(data, &opts);
+ ret = check_cgroupfs_options(fc);
if (ret)
goto out_unlock;
- if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
+ if (ctx->subsys_mask != root->subsys_mask || ctx->release_agent)
pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
task_tgid_nr(current), current->comm);
- added_mask = opts.subsys_mask & ~root->subsys_mask;
- removed_mask = root->subsys_mask & ~opts.subsys_mask;
+ added_mask = ctx->subsys_mask & ~root->subsys_mask;
+ removed_mask = root->subsys_mask & ~ctx->subsys_mask;
/* Don't allow flags or name to change at remount */
- if ((opts.flags ^ root->flags) ||
- (opts.name && strcmp(opts.name, root->name))) {
- pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
- opts.flags, opts.name ?: "", root->flags, root->name);
+ if ((ctx->flags ^ root->flags) ||
+ (ctx->name && strcmp(ctx->name, root->name))) {
+ cg_invalf(fc, "option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"",
+ ctx->flags, ctx->name ?: "", root->flags, root->name);
ret = -EINVAL;
goto out_unlock;
}
@@ -1081,17 +1080,15 @@
WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
- if (opts.release_agent) {
+ if (ctx->release_agent) {
spin_lock(&release_agent_path_lock);
- strcpy(root->release_agent_path, opts.release_agent);
+ strcpy(root->release_agent_path, ctx->release_agent);
spin_unlock(&release_agent_path_lock);
}
trace_cgroup_remount(root);
out_unlock:
- kfree(opts.release_agent);
- kfree(opts.name);
mutex_unlock(&cgroup_mutex);
return ret;
}
@@ -1099,30 +1096,30 @@
struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {
.rename = cgroup1_rename,
.show_options = cgroup1_show_options,
- .remount_fs = cgroup1_remount,
.mkdir = cgroup_mkdir,
.rmdir = cgroup_rmdir,
.show_path = cgroup_show_path,
};
-struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags,
- void *data, unsigned long magic,
- struct cgroup_namespace *ns)
+/*
+ * The guts of cgroup1 mount - find or create cgroup_root to use.
+ * Called with cgroup_mutex held; returns 0 on success, -E... on
+ * error and positive - in case when the candidate is busy dying.
+ * On success it stashes a reference to cgroup_root into given
+ * cgroup_fs_context; that reference is *NOT* counting towards the
+ * cgroup_root refcount.
+ */
+static int cgroup1_root_to_use(struct fs_context *fc)
{
- struct super_block *pinned_sb = NULL;
- struct cgroup_sb_opts opts;
+ struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
struct cgroup_root *root;
struct cgroup_subsys *ss;
- struct dentry *dentry;
int i, ret;
- bool new_root = false;
-
- cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
/* First find the desired set of subsystems */
- ret = parse_cgroupfs_options(data, &opts);
+ ret = check_cgroupfs_options(fc);
if (ret)
- goto out_unlock;
+ return ret;
/*
* Destruction of cgroup root is asynchronous, so subsystems may
@@ -1132,16 +1129,12 @@
* starting. Testing ref liveliness is good enough.
*/
for_each_subsys(ss, i) {
- if (!(opts.subsys_mask & (1 << i)) ||
+ if (!(ctx->subsys_mask & (1 << i)) ||
ss->root == &cgrp_dfl_root)
continue;
- if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {
- mutex_unlock(&cgroup_mutex);
- msleep(10);
- ret = restart_syscall();
- goto out_free;
- }
+ if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt))
+ return 1; /* restart */
cgroup_put(&ss->root->cgrp);
}
@@ -1156,8 +1149,8 @@
* name matches but sybsys_mask doesn't, we should fail.
* Remember whether name matched.
*/
- if (opts.name) {
- if (strcmp(opts.name, root->name))
+ if (ctx->name) {
+ if (strcmp(ctx->name, root->name))
continue;
name_match = true;
}
@@ -1166,42 +1159,18 @@
* If we asked for subsystems (or explicitly for no
* subsystems) then they must match.
*/
- if ((opts.subsys_mask || opts.none) &&
- (opts.subsys_mask != root->subsys_mask)) {
+ if ((ctx->subsys_mask || ctx->none) &&
+ (ctx->subsys_mask != root->subsys_mask)) {
if (!name_match)
continue;
- ret = -EBUSY;
- goto out_unlock;
+ return -EBUSY;
}
- if (root->flags ^ opts.flags)
+ if (root->flags ^ ctx->flags)
pr_warn("new mount options do not match the existing superblock, will be ignored\n");
- /*
- * We want to reuse @root whose lifetime is governed by its
- * ->cgrp. Let's check whether @root is alive and keep it
- * that way. As cgroup_kill_sb() can happen anytime, we
- * want to block it by pinning the sb so that @root doesn't
- * get killed before mount is complete.
- *
- * With the sb pinned, tryget_live can reliably indicate
- * whether @root can be reused. If it's being killed,
- * drain it. We can use wait_queue for the wait but this
- * path is super cold. Let's just sleep a bit and retry.
- */
- pinned_sb = kernfs_pin_sb(root->kf_root, NULL);
- if (IS_ERR(pinned_sb) ||
- !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {
- mutex_unlock(&cgroup_mutex);
- if (!IS_ERR_OR_NULL(pinned_sb))
- deactivate_super(pinned_sb);
- msleep(10);
- ret = restart_syscall();
- goto out_free;
- }
-
- ret = 0;
- goto out_unlock;
+ ctx->root = root;
+ return 0;
}
/*
@@ -1209,62 +1178,58 @@
* specification is allowed for already existing hierarchies but we
* can't create new one without subsys specification.
*/
- if (!opts.subsys_mask && !opts.none) {
- ret = -EINVAL;
- goto out_unlock;
- }
+ if (!ctx->subsys_mask && !ctx->none)
+ return cg_invalf(fc, "cgroup1: No subsys list or none specified");
/* Hierarchies may only be created in the initial cgroup namespace. */
- if (ns != &init_cgroup_ns) {
- ret = -EPERM;
- goto out_unlock;
- }
+ if (ctx->ns != &init_cgroup_ns)
+ return -EPERM;
root = kzalloc(sizeof(*root), GFP_KERNEL);
- if (!root) {
- ret = -ENOMEM;
- goto out_unlock;
- }
- new_root = true;
+ if (!root)
+ return -ENOMEM;
- init_cgroup_root(root, &opts);
+ ctx->root = root;
+ init_cgroup_root(ctx);
- ret = cgroup_setup_root(root, opts.subsys_mask, PERCPU_REF_INIT_DEAD);
+ ret = cgroup_setup_root(root, ctx->subsys_mask);
if (ret)
cgroup_free_root(root);
+ return ret;
+}
-out_unlock:
+int cgroup1_get_tree(struct fs_context *fc)
+{
+ struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
+ int ret;
+
+ /* Check if the caller has permission to mount. */
+ if (!ns_capable(ctx->ns->user_ns, CAP_SYS_ADMIN))
+ return -EPERM;
+
+ cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
+
+ ret = cgroup1_root_to_use(fc);
+ if (!ret && !percpu_ref_tryget_live(&ctx->root->cgrp.self.refcnt))
+ ret = 1; /* restart */
+
mutex_unlock(&cgroup_mutex);
-out_free:
- kfree(opts.release_agent);
- kfree(opts.name);
- if (ret)
- return ERR_PTR(ret);
+ if (!ret)
+ ret = cgroup_do_get_tree(fc);
- dentry = cgroup_do_mount(&cgroup_fs_type, flags, root,
- CGROUP_SUPER_MAGIC, ns);
-
- /*
- * There's a race window after we release cgroup_mutex and before
- * allocating a superblock. Make sure a concurrent process won't
- * be able to re-use the root during this window by delaying the
- * initialization of root refcnt.
- */
- if (new_root) {
- mutex_lock(&cgroup_mutex);
- percpu_ref_reinit(&root->cgrp.self.refcnt);
- mutex_unlock(&cgroup_mutex);
+ if (!ret && percpu_ref_is_dying(&ctx->root->cgrp.self.refcnt)) {
+ struct super_block *sb = fc->root->d_sb;
+ dput(fc->root);
+ deactivate_locked_super(sb);
+ ret = 1;
}
- /*
- * If @pinned_sb, we're reusing an existing root and holding an
- * extra ref on its sb. Mount is complete. Put the extra ref.
- */
- if (pinned_sb)
- deactivate_super(pinned_sb);
-
- return dentry;
+ if (unlikely(ret > 0)) {
+ msleep(10);
+ return restart_syscall();
+ }
+ return ret;
}
static int __init cgroup1_wq_init(void)
@@ -1292,7 +1257,12 @@
if (!strcmp(token, "all")) {
cgroup_no_v1_mask = U16_MAX;
- break;
+ continue;
+ }
+
+ if (!strcmp(token, "named")) {
+ cgroup_no_v1_named = true;
+ continue;
}
for_each_subsys(ss, i) {