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authorLinus Torvalds <torvalds@linux-foundation.org>2015-12-08 13:35:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-12-08 13:35:52 -0800
commit5406812e59761f6ba33ea0bf97e426666bdb0e28 (patch)
treee332877ab352be841ff709f307c6d70788771044
parent633bb7388bf399b2d4b16951404d69f34f9ddbec (diff)
parent0b98f0c04245877ae0b625a7f0aa55b8ff98e0c4 (diff)
Merge branch 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo: "More change than I'd have liked at this stage. The pids controller and the changes made to cgroup core to support it introduced and revealed several important issues. - Assigning membership to a newly created task and migrating it can race leading to incorrect accounting. Oleg fixed it by widening threadgroup synchronization. It looks like we'll be able to merge it with a different percpu rwsem which is used in fork path making things simpler and cheaper. - The recent change to extend cgroup membership to zombies (so that pid accounting can extend till the pid is actually released) missed pinning the underlying data structures leading to use-after-free. Fixed. - v2 hierarchy was calling subsystem callbacks with the wrong target cgroup_subsys_state based on the incorrect assumption that they share the same target. pids is the first controller affected by this. Subsys callbacks updated so that they can deal with multi-target migrations" * 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup_pids: don't account for the root cgroup cgroup: fix handling of multi-destination migration from subtree_control enabling cgroup_freezer: simplify propagation of CGROUP_FROZEN clearing in freezer_attach() cgroup: pids: kill pids_fork(), simplify pids_can_fork() and pids_cancel_fork() cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate() cgroup: make css_set pin its css's to avoid use-afer-free cgroup: fix cftype->file_offset handling
-rw-r--r--block/blk-cgroup.c6
-rw-r--r--include/linux/cgroup-defs.h13
-rw-r--r--include/linux/cgroup.h47
-rw-r--r--kernel/cgroup.c99
-rw-r--r--kernel/cgroup_freezer.c23
-rw-r--r--kernel/cgroup_pids.c77
-rw-r--r--kernel/cpuset.c33
-rw-r--r--kernel/events/core.c6
-rw-r--r--kernel/fork.c9
-rw-r--r--kernel/sched/core.c12
-rw-r--r--mm/memcontrol.c45
-rw-r--r--net/core/netclassid_cgroup.c6
-rw-r--r--net/core/netprio_cgroup.c9
13 files changed, 202 insertions, 183 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 5bcdfc10c23a..5a37188b559f 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1127,15 +1127,15 @@ void blkcg_exit_queue(struct request_queue *q)
* of the main cic data structures. For now we allow a task to change
* its cgroup only if it's the only owner of its ioc.
*/
-static int blkcg_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int blkcg_can_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
+ struct cgroup_subsys_state *dst_css;
struct io_context *ioc;
int ret = 0;
/* task_lock() is needed to avoid races with exit_io_context() */
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, dst_css, tset) {
task_lock(task);
ioc = task->io_context;
if (ioc && atomic_read(&ioc->nr_tasks) > 1)
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 60d44b26276d..06b77f9dd3f2 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -90,7 +90,6 @@ enum {
*/
struct cgroup_file {
/* do not access any fields from outside cgroup core */
- struct list_head node; /* anchored at css->files */
struct kernfs_node *kn;
};
@@ -134,9 +133,6 @@ struct cgroup_subsys_state {
*/
u64 serial_nr;
- /* all cgroup_files associated with this css */
- struct list_head files;
-
/* percpu_ref killing and RCU release */
struct rcu_head rcu_head;
struct work_struct destroy_work;
@@ -426,12 +422,9 @@ struct cgroup_subsys {
void (*css_reset)(struct cgroup_subsys_state *css);
void (*css_e_css_changed)(struct cgroup_subsys_state *css);
- int (*can_attach)(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset);
- void (*cancel_attach)(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset);
- void (*attach)(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset);
+ int (*can_attach)(struct cgroup_taskset *tset);
+ void (*cancel_attach)(struct cgroup_taskset *tset);
+ void (*attach)(struct cgroup_taskset *tset);
int (*can_fork)(struct task_struct *task, void **priv_p);
void (*cancel_fork)(struct task_struct *task, void *priv);
void (*fork)(struct task_struct *task, void *priv);
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 22e3754f89c5..cb91b44f5f78 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -88,6 +88,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_rm_cftypes(struct cftype *cfts);
+void cgroup_file_notify(struct cgroup_file *cfile);
char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
@@ -119,8 +120,10 @@ struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state
struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
struct cgroup_subsys_state *css);
-struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset);
-struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
+struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
+ struct cgroup_subsys_state **dst_cssp);
+struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
+ struct cgroup_subsys_state **dst_cssp);
void css_task_iter_start(struct cgroup_subsys_state *css,
struct css_task_iter *it);
@@ -235,30 +238,39 @@ void css_task_iter_end(struct css_task_iter *it);
/**
* cgroup_taskset_for_each - iterate cgroup_taskset
* @task: the loop cursor
+ * @dst_css: the destination css
* @tset: taskset to iterate
*
* @tset may contain multiple tasks and they may belong to multiple
- * processes. When there are multiple tasks in @tset, if a task of a
- * process is in @tset, all tasks of the process are in @tset. Also, all
- * are guaranteed to share the same source and destination csses.
+ * processes.
+ *
+ * On the v2 hierarchy, there may be tasks from multiple processes and they
+ * may not share the source or destination csses.
+ *
+ * On traditional hierarchies, when there are multiple tasks in @tset, if a
+ * task of a process is in @tset, all tasks of the process are in @tset.
+ * Also, all are guaranteed to share the same source and destination csses.
*
* Iteration is not in any specific order.
*/
-#define cgroup_taskset_for_each(task, tset) \
- for ((task) = cgroup_taskset_first((tset)); (task); \
- (task) = cgroup_taskset_next((tset)))
+#define cgroup_taskset_for_each(task, dst_css, tset) \
+ for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
+ (task); \
+ (task) = cgroup_taskset_next((tset), &(dst_css)))
/**
* cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
* @leader: the loop cursor
+ * @dst_css: the destination css
* @tset: takset to iterate
*
* Iterate threadgroup leaders of @tset. For single-task migrations, @tset
* may not contain any.
*/
-#define cgroup_taskset_for_each_leader(leader, tset) \
- for ((leader) = cgroup_taskset_first((tset)); (leader); \
- (leader) = cgroup_taskset_next((tset))) \
+#define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
+ for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
+ (leader); \
+ (leader) = cgroup_taskset_next((tset), &(dst_css))) \
if ((leader) != (leader)->group_leader) \
; \
else
@@ -516,19 +528,6 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
pr_cont_kernfs_path(cgrp->kn);
}
-/**
- * cgroup_file_notify - generate a file modified event for a cgroup_file
- * @cfile: target cgroup_file
- *
- * @cfile must have been obtained by setting cftype->file_offset.
- */
-static inline void cgroup_file_notify(struct cgroup_file *cfile)
-{
- /* might not have been created due to one of the CFTYPE selector flags */
- if (cfile->kn)
- kernfs_notify(cfile->kn);
-}
-
#else /* !CONFIG_CGROUPS */
struct cgroup_subsys_state;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f1603c153890..470f6536b9e8 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -98,6 +98,12 @@ static DEFINE_SPINLOCK(css_set_lock);
static DEFINE_SPINLOCK(cgroup_idr_lock);
/*
+ * Protects cgroup_file->kn for !self csses. It synchronizes notifications
+ * against file removal/re-creation across css hiding.
+ */
+static DEFINE_SPINLOCK(cgroup_file_kn_lock);
+
+/*
* Protects cgroup_subsys->release_agent_path. Modifying it also requires
* cgroup_mutex. Reading requires either cgroup_mutex or this spinlock.
*/
@@ -754,9 +760,11 @@ static void put_css_set_locked(struct css_set *cset)
if (!atomic_dec_and_test(&cset->refcount))
return;
- /* This css_set is dead. unlink it and release cgroup refcounts */
- for_each_subsys(ss, ssid)
+ /* This css_set is dead. unlink it and release cgroup and css refs */
+ for_each_subsys(ss, ssid) {
list_del(&cset->e_cset_node[ssid]);
+ css_put(cset->subsys[ssid]);
+ }
hash_del(&cset->hlist);
css_set_count--;
@@ -1056,9 +1064,13 @@ static struct css_set *find_css_set(struct css_set *old_cset,
key = css_set_hash(cset->subsys);
hash_add(css_set_table, &cset->hlist, key);
- for_each_subsys(ss, ssid)
+ for_each_subsys(ss, ssid) {
+ struct cgroup_subsys_state *css = cset->subsys[ssid];
+
list_add_tail(&cset->e_cset_node[ssid],
- &cset->subsys[ssid]->cgroup->e_csets[ssid]);
+ &css->cgroup->e_csets[ssid]);
+ css_get(css);
+ }
spin_unlock_bh(&css_set_lock);
@@ -1393,6 +1405,16 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
char name[CGROUP_FILE_NAME_MAX];
lockdep_assert_held(&cgroup_mutex);
+
+ if (cft->file_offset) {
+ struct cgroup_subsys_state *css = cgroup_css(cgrp, cft->ss);
+ struct cgroup_file *cfile = (void *)css + cft->file_offset;
+
+ spin_lock_irq(&cgroup_file_kn_lock);
+ cfile->kn = NULL;
+ spin_unlock_irq(&cgroup_file_kn_lock);
+ }
+
kernfs_remove_by_name(cgrp->kn, cgroup_file_name(cgrp, cft, name));
}
@@ -1856,7 +1878,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
INIT_LIST_HEAD(&cgrp->self.sibling);
INIT_LIST_HEAD(&cgrp->self.children);
- INIT_LIST_HEAD(&cgrp->self.files);
INIT_LIST_HEAD(&cgrp->cset_links);
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
@@ -2216,6 +2237,9 @@ struct cgroup_taskset {
struct list_head src_csets;
struct list_head dst_csets;
+ /* the subsys currently being processed */
+ int ssid;
+
/*
* Fields for cgroup_taskset_*() iteration.
*
@@ -2278,25 +2302,29 @@ static void cgroup_taskset_add(struct task_struct *task,
/**
* cgroup_taskset_first - reset taskset and return the first task
* @tset: taskset of interest
+ * @dst_cssp: output variable for the destination css
*
* @tset iteration is initialized and the first task is returned.
*/
-struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset)
+struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
+ struct cgroup_subsys_state **dst_cssp)
{
tset->cur_cset = list_first_entry(tset->csets, struct css_set, mg_node);
tset->cur_task = NULL;
- return cgroup_taskset_next(tset);
+ return cgroup_taskset_next(tset, dst_cssp);
}
/**
* cgroup_taskset_next - iterate to the next task in taskset
* @tset: taskset of interest
+ * @dst_cssp: output variable for the destination css
*
* Return the next task in @tset. Iteration must have been initialized
* with cgroup_taskset_first().
*/
-struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
+struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
+ struct cgroup_subsys_state **dst_cssp)
{
struct css_set *cset = tset->cur_cset;
struct task_struct *task = tset->cur_task;
@@ -2311,6 +2339,18 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
if (&task->cg_list != &cset->mg_tasks) {
tset->cur_cset = cset;
tset->cur_task = task;
+
+ /*
+ * This function may be called both before and
+ * after cgroup_taskset_migrate(). The two cases
+ * can be distinguished by looking at whether @cset
+ * has its ->mg_dst_cset set.
+ */
+ if (cset->mg_dst_cset)
+ *dst_cssp = cset->mg_dst_cset->subsys[tset->ssid];
+ else
+ *dst_cssp = cset->subsys[tset->ssid];
+
return task;
}
@@ -2346,7 +2386,8 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
/* check that we can legitimately attach to the cgroup */
for_each_e_css(css, i, dst_cgrp) {
if (css->ss->can_attach) {
- ret = css->ss->can_attach(css, tset);
+ tset->ssid = i;
+ ret = css->ss->can_attach(tset);
if (ret) {
failed_css = css;
goto out_cancel_attach;
@@ -2379,9 +2420,12 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
*/
tset->csets = &tset->dst_csets;
- for_each_e_css(css, i, dst_cgrp)
- if (css->ss->attach)
- css->ss->attach(css, tset);
+ for_each_e_css(css, i, dst_cgrp) {
+ if (css->ss->attach) {
+ tset->ssid = i;
+ css->ss->attach(tset);
+ }
+ }
ret = 0;
goto out_release_tset;
@@ -2390,8 +2434,10 @@ out_cancel_attach:
for_each_e_css(css, i, dst_cgrp) {
if (css == failed_css)
break;
- if (css->ss->cancel_attach)
- css->ss->cancel_attach(css, tset);
+ if (css->ss->cancel_attach) {
+ tset->ssid = i;
+ css->ss->cancel_attach(tset);
+ }
}
out_release_tset:
spin_lock_bh(&css_set_lock);
@@ -3313,9 +3359,9 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
if (cft->file_offset) {
struct cgroup_file *cfile = (void *)css + cft->file_offset;
- kernfs_get(kn);
+ spin_lock_irq(&cgroup_file_kn_lock);
cfile->kn = kn;
- list_add(&cfile->node, &css->files);
+ spin_unlock_irq(&cgroup_file_kn_lock);
}
return 0;
@@ -3553,6 +3599,22 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
}
/**
+ * cgroup_file_notify - generate a file modified event for a cgroup_file
+ * @cfile: target cgroup_file
+ *
+ * @cfile must have been obtained by setting cftype->file_offset.
+ */
+void cgroup_file_notify(struct cgroup_file *cfile)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cgroup_file_kn_lock, flags);
+ if (cfile->kn)
+ kernfs_notify(cfile->kn);
+ spin_unlock_irqrestore(&cgroup_file_kn_lock, flags);
+}
+
+/**
* cgroup_task_count - count the number of tasks in a cgroup.
* @cgrp: the cgroup in question
*
@@ -4613,13 +4675,9 @@ static void css_free_work_fn(struct work_struct *work)
container_of(work, struct cgroup_subsys_state, destroy_work);
struct cgroup_subsys *ss = css->ss;
struct cgroup *cgrp = css->cgroup;
- struct cgroup_file *cfile;
percpu_ref_exit(&css->refcnt);
- list_for_each_entry(cfile, &css->files, node)
- kernfs_put(cfile->kn);
-
if (ss) {
/* css free path */
int id = css->id;
@@ -4724,7 +4782,6 @@ static void init_and_link_css(struct cgroup_subsys_state *css,
css->ss = ss;
INIT_LIST_HEAD(&css->sibling);
INIT_LIST_HEAD(&css->children);
- INIT_LIST_HEAD(&css->files);
css->serial_nr = css_serial_nr_next++;
if (cgroup_parent(cgrp)) {
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index f1b30ad5dc6d..2d3df82c54f2 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -155,12 +155,10 @@ static void freezer_css_free(struct cgroup_subsys_state *css)
* @freezer->lock. freezer_attach() makes the new tasks conform to the
* current state and all following state changes can see the new tasks.
*/
-static void freezer_attach(struct cgroup_subsys_state *new_css,
- struct cgroup_taskset *tset)
+static void freezer_attach(struct cgroup_taskset *tset)
{
- struct freezer *freezer = css_freezer(new_css);
struct task_struct *task;
- bool clear_frozen = false;
+ struct cgroup_subsys_state *new_css;
mutex_lock(&freezer_mutex);
@@ -174,22 +172,21 @@ static void freezer_attach(struct cgroup_subsys_state *new_css,
* current state before executing the following - !frozen tasks may
* be visible in a FROZEN cgroup and frozen tasks in a THAWED one.
*/
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, new_css, tset) {
+ struct freezer *freezer = css_freezer(new_css);
+
if (!(freezer->state & CGROUP_FREEZING)) {
__thaw_task(task);
} else {
freeze_task(task);
- freezer->state &= ~CGROUP_FROZEN;
- clear_frozen = true;
+ /* clear FROZEN and propagate upwards */
+ while (freezer && (freezer->state & CGROUP_FROZEN)) {
+ freezer->state &= ~CGROUP_FROZEN;
+ freezer = parent_freezer(freezer);
+ }
}
}
- /* propagate FROZEN clearing upwards */
- while (clear_frozen && (freezer = parent_freezer(freezer))) {
- freezer->state &= ~CGROUP_FROZEN;
- clear_frozen = freezer->state & CGROUP_FREEZING;
- }
-
mutex_unlock(&freezer_mutex);
}
diff --git a/kernel/cgroup_pids.c b/kernel/cgroup_pids.c
index cdd8df4e991c..b50d5a167fda 100644
--- a/kernel/cgroup_pids.c
+++ b/kernel/cgroup_pids.c
@@ -106,7 +106,7 @@ static void pids_uncharge(struct pids_cgroup *pids, int num)
{
struct pids_cgroup *p;
- for (p = pids; p; p = parent_pids(p))
+ for (p = pids; parent_pids(p); p = parent_pids(p))
pids_cancel(p, num);
}
@@ -123,7 +123,7 @@ static void pids_charge(struct pids_cgroup *pids, int num)
{
struct pids_cgroup *p;
- for (p = pids; p; p = parent_pids(p))
+ for (p = pids; parent_pids(p); p = parent_pids(p))
atomic64_add(num, &p->counter);
}
@@ -140,7 +140,7 @@ static int pids_try_charge(struct pids_cgroup *pids, int num)
{
struct pids_cgroup *p, *q;
- for (p = pids; p; p = parent_pids(p)) {
+ for (p = pids; parent_pids(p); p = parent_pids(p)) {
int64_t new = atomic64_add_return(num, &p->counter);
/*
@@ -162,13 +162,13 @@ revert:
return -EAGAIN;
}
-static int pids_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int pids_can_attach(struct cgroup_taskset *tset)
{
- struct pids_cgroup *pids = css_pids(css);
struct task_struct *task;
+ struct cgroup_subsys_state *dst_css;
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, dst_css, tset) {
+ struct pids_cgroup *pids = css_pids(dst_css);
struct cgroup_subsys_state *old_css;
struct pids_cgroup *old_pids;
@@ -187,13 +187,13 @@ static int pids_can_attach(struct cgroup_subsys_state *css,
return 0;
}
-static void pids_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void pids_cancel_attach(struct cgroup_taskset *tset)
{
- struct pids_cgroup *pids = css_pids(css);
struct task_struct *task;
+ struct cgroup_subsys_state *dst_css;
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, dst_css, tset) {
+ struct pids_cgroup *pids = css_pids(dst_css);
struct cgroup_subsys_state *old_css;
struct pids_cgroup *old_pids;
@@ -205,65 +205,28 @@ static void pids_cancel_attach(struct cgroup_subsys_state *css,
}
}
+/*
+ * task_css_check(true) in pids_can_fork() and pids_cancel_fork() relies
+ * on threadgroup_change_begin() held by the copy_process().
+ */
static int pids_can_fork(struct task_struct *task, void **priv_p)
{
struct cgroup_subsys_state *css;
struct pids_cgroup *pids;
- int err;
- /*
- * Use the "current" task_css for the pids subsystem as the tentative
- * css. It is possible we will charge the wrong hierarchy, in which
- * case we will forcefully revert/reapply the charge on the right
- * hierarchy after it is committed to the task proper.
- */
- css = task_get_css(current, pids_cgrp_id);
+ css = task_css_check(current, pids_cgrp_id, true);
pids = css_pids(css);
-
- err = pids_try_charge(pids, 1);
- if (err)
- goto err_css_put;
-
- *priv_p = css;
- return 0;
-
-err_css_put:
- css_put(css);
- return err;
+ return pids_try_charge(pids, 1);
}
static void pids_cancel_fork(struct task_struct *task, void *priv)
{
- struct cgroup_subsys_state *css = priv;
- struct pids_cgroup *pids = css_pids(css);
-
- pids_uncharge(pids, 1);
- css_put(css);
-}
-
-static void pids_fork(struct task_struct *task, void *priv)
-{
struct cgroup_subsys_state *css;
- struct cgroup_subsys_state *old_css = priv;
struct pids_cgroup *pids;
- struct pids_cgroup *old_pids = css_pids(old_css);
- css = task_get_css(task, pids_cgrp_id);
+ css = task_css_check(current, pids_cgrp_id, true);
pids = css_pids(css);
-
- /*
- * If the association has changed, we have to revert and reapply the
- * charge/uncharge on the wrong hierarchy to the current one. Since
- * the association can only change due to an organisation event, its
- * okay for us to ignore the limit in this case.
- */
- if (pids != old_pids) {
- pids_uncharge(old_pids, 1);
- pids_charge(pids, 1);
- }
-
- css_put(css);
- css_put(old_css);
+ pids_uncharge(pids, 1);
}
static void pids_free(struct task_struct *task)
@@ -335,6 +298,7 @@ static struct cftype pids_files[] = {
{
.name = "current",
.read_s64 = pids_current_read,
+ .flags = CFTYPE_NOT_ON_ROOT,
},
{ } /* terminate */
};
@@ -346,7 +310,6 @@ struct cgroup_subsys pids_cgrp_subsys = {
.cancel_attach = pids_cancel_attach,
.can_fork = pids_can_fork,
.cancel_fork = pids_cancel_fork,
- .fork = pids_fork,
.free = pids_free,
.legacy_cftypes = pids_files,
.dfl_cftypes = pids_files,
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 10ae73611d80..02a8ea5c9963 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1429,15 +1429,16 @@ static int fmeter_getrate(struct fmeter *fmp)
static struct cpuset *cpuset_attach_old_cs;
/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int cpuset_can_attach(struct cgroup_taskset *tset)
{
- struct cpuset *cs = css_cs(css);
+ struct cgroup_subsys_state *css;
+ struct cpuset *cs;
struct task_struct *task;
int ret;
/* used later by cpuset_attach() */
- cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset));
+ cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css));
+ cs = css_cs(css);
mutex_lock(&cpuset_mutex);
@@ -1447,7 +1448,7 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
(cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
goto out_unlock;
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
ret = task_can_attach(task, cs->cpus_allowed);
if (ret)
goto out_unlock;
@@ -1467,9 +1468,14 @@ out_unlock:
return ret;
}
-static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void cpuset_cancel_attach(struct cgroup_taskset *tset)
{
+ struct cgroup_subsys_state *css;
+ struct cpuset *cs;
+
+ cgroup_taskset_first(tset, &css);
+ cs = css_cs(css);
+
mutex_lock(&cpuset_mutex);
css_cs(css)->attach_in_progress--;
mutex_unlock(&cpuset_mutex);
@@ -1482,16 +1488,19 @@ static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
*/
static cpumask_var_t cpus_attach;
-static void cpuset_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void cpuset_attach(struct cgroup_taskset *tset)
{
/* static buf protected by cpuset_mutex */
static nodemask_t cpuset_attach_nodemask_to;
struct task_struct *task;
struct task_struct *leader;
- struct cpuset *cs = css_cs(css);
+ struct cgroup_subsys_state *css;
+ struct cpuset *cs;
struct cpuset *oldcs = cpuset_attach_old_cs;
+ cgroup_taskset_first(tset, &css);
+ cs = css_cs(css);
+
mutex_lock(&cpuset_mutex);
/* prepare for attach */
@@ -1502,7 +1511,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
/*
* can_attach beforehand should guarantee that this doesn't
* fail. TODO: have a better way to handle failure here
@@ -1518,7 +1527,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
* sleep and should be moved outside migration path proper.
*/
cpuset_attach_nodemask_to = cs->effective_mems;
- cgroup_taskset_for_each_leader(leader, tset) {
+ cgroup_taskset_for_each_leader(leader, css, tset) {
struct mm_struct *mm = get_task_mm(leader);
if (mm) {
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 39cf4a40aa4c..ef2d6ea10736 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9494,12 +9494,12 @@ static int __perf_cgroup_move(void *info)
return 0;
}
-static void perf_cgroup_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void perf_cgroup_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
+ struct cgroup_subsys_state *css;
- cgroup_taskset_for_each(task, tset)
+ cgroup_taskset_for_each(task, css, tset)
task_function_call(task, __perf_cgroup_move, task);
}
diff --git a/kernel/fork.c b/kernel/fork.c
index f97f2c449f5c..fce002ee3ddf 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1368,8 +1368,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->real_start_time = ktime_get_boot_ns();
p->io_context = NULL;
p->audit_context = NULL;
- if (clone_flags & CLONE_THREAD)
- threadgroup_change_begin(current);
+ threadgroup_change_begin(current);
cgroup_fork(p);
#ifdef CONFIG_NUMA
p->mempolicy = mpol_dup(p->mempolicy);
@@ -1610,8 +1609,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
proc_fork_connector(p);
cgroup_post_fork(p, cgrp_ss_priv);
- if (clone_flags & CLONE_THREAD)
- threadgroup_change_end(current);
+ threadgroup_change_end(current);
perf_event_fork(p);
trace_task_newtask(p, clone_flags);
@@ -1652,8 +1650,7 @@ bad_fork_cleanup_policy:
mpol_put(p->mempolicy);
bad_fork_cleanup_threadgroup_lock:
#endif
- if (clone_flags & CLONE_THREAD)
- threadgroup_change_end(current);
+ threadgroup_change_end(current);
delayacct_tsk_free(p);
bad_fork_cleanup_count:
atomic_dec(&p->cred->user->processes);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7063c6a07440..732e993b564b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8241,12 +8241,12 @@ static void cpu_cgroup_fork(struct task_struct *task, void *private)
sched_move_task(task);
}
-static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int cpu_cgroup_can_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
+ struct cgroup_subsys_state *css;
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
#ifdef CONFIG_RT_GROUP_SCHED
if (!sched_rt_can_attach(css_tg(css), task))
return -EINVAL;
@@ -8259,12 +8259,12 @@ static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
return 0;
}
-static void cpu_cgroup_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void cpu_cgroup_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
+ struct cgroup_subsys_state *css;
- cgroup_taskset_for_each(task, tset)
+ cgroup_taskset_for_each(task, css, tset)
sched_move_task(task);
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9acfb165eb52..c92a65b2b4ab 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4779,23 +4779,18 @@ static void mem_cgroup_clear_mc(void)
spin_unlock(&mc.lock);
}
-static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct cgroup_subsys_state *css;
+ struct mem_cgroup *memcg;
struct mem_cgroup *from;
struct task_struct *leader, *p;
struct mm_struct *mm;
unsigned long move_flags;
int ret = 0;
- /*
- * We are now commited to this value whatever it is. Changes in this
- * tunable will only affect upcoming migrations, not the current one.
- * So we need to save it, and keep it going.
- */
- move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
- if (!move_flags)
+ /* charge immigration isn't supported on the default hierarchy */
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
return 0;
/*
@@ -4805,13 +4800,23 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
* multiple.
*/
p = NULL;
- cgroup_taskset_for_each_leader(leader, tset) {
+ cgroup_taskset_for_each_leader(leader, css, tset) {
WARN_ON_ONCE(p);
p = leader;
+ memcg = mem_cgroup_from_css(css);
}
if (!p)
return 0;
+ /*
+ * We are now commited to this value whatever it is. Changes in this
+ * tunable will only affect upcoming migrations, not the current one.
+ * So we need to save it, and keep it going.
+ */
+ move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
+ if (!move_flags)
+ return 0;
+
from = mem_cgroup_from_task(p);
VM_BUG_ON(from == memcg);
@@ -4842,8 +4847,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
return ret;
}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
{
if (mc.to)
mem_cgroup_clear_mc();
@@ -4985,10 +4989,10 @@ retry:
atomic_dec(&mc.from->moving_account);
}
-static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup_taskset *tset)
{
- struct task_struct *p = cgroup_taskset_first(tset);
+ struct cgroup_subsys_state *css;
+ struct task_struct *p = cgroup_taskset_first(tset, &css);
struct mm_struct *mm = get_task_mm(p);
if (mm) {
@@ -5000,17 +5004,14 @@ static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
mem_cgroup_clear_mc();
}
#else /* !CONFIG_MMU */
-static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
{
return 0;
}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
{
}
-static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup_taskset *tset)
{
}
#endif
diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c
index 2e4df84c34a1..d9ee8d08a3a6 100644
--- a/net/core/netclassid_cgroup.c
+++ b/net/core/netclassid_cgroup.c
@@ -81,9 +81,11 @@ static void update_classid(struct cgroup_subsys_state *css, void *v)
css_task_iter_end(&it);
}
-static void cgrp_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void cgrp_attach(struct cgroup_taskset *tset)
{
+ struct cgroup_subsys_state *css;
+
+ cgroup_taskset_first(tset, &css);
update_classid(css,
(void *)(unsigned long)css_cls_state(css)->classid);
}
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index cbd0a199bf52..40fd09fe06ae 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -218,13 +218,14 @@ static int update_netprio(const void *v, struct file *file, unsigned n)
return 0;
}
-static void net_prio_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void net_prio_attach(struct cgroup_taskset *tset)
{
struct task_struct *p;
- void *v = (void *)(unsigned long)css->cgroup->id;
+ struct cgroup_subsys_state *css;
+
+ cgroup_taskset_for_each(p, css, tset) {
+ void *v = (void *)(unsigned long)css->cgroup->id;
- cgroup_taskset_for_each(p, tset) {
task_lock(p);
iterate_fd(p->files, 0, update_netprio, v);
task_unlock(p);