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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-10 15:05:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-10 15:05:45 -0700
commite941484541036ba3652b658ed5536c7bca5bdb89 (patch)
tree5d89b30474126b313205ca24e66b2deee521bda2 /kernel
parent2c1aca4bd3fefc57018773cc8771f71c9bfbdc1f (diff)
parent2e5383d7904e60529136727e49629a82058a5607 (diff)
Merge branch 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo: - cgroup.procs listing related fixes. It didn't interlock properly with exiting tasks leaving a short window where a cgroup has empty cgroup.procs but still can't be removed and misbehaved on short reads. - psi_show() crash fix on 32bit ino archs - Empty release_agent handling fix * 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup1: don't call release_agent when it is "" cgroup: fix psi_show() crash on 32bit ino archs cgroup: Iterate tasks that did not finish do_exit() cgroup: cgroup_procs_next should increase position index cgroup-v1: cgroup_pidlist_next should update position index
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup/cgroup-v1.c3
-rw-r--r--kernel/cgroup/cgroup.c39
2 files changed, 28 insertions, 14 deletions
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index be1a1c83cdd1..f2d7cea86ffe 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -471,6 +471,7 @@ static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
*/
p++;
if (p >= end) {
+ (*pos)++;
return NULL;
} else {
*pos = *p;
@@ -782,7 +783,7 @@ void cgroup1_release_agent(struct work_struct *work)
pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
- if (!pathbuf || !agentbuf)
+ if (!pathbuf || !agentbuf || !strlen(agentbuf))
goto out;
spin_lock_irq(&css_set_lock);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 75f687301bbf..7a39dc882095 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3542,21 +3542,21 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
+ struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_IO);
}
static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
+ struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_MEM);
}
static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
+ struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_CPU);
}
@@ -4400,12 +4400,16 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
}
} while (!css_set_populated(cset) && list_empty(&cset->dying_tasks));
- if (!list_empty(&cset->tasks))
+ if (!list_empty(&cset->tasks)) {
it->task_pos = cset->tasks.next;
- else if (!list_empty(&cset->mg_tasks))
+ it->cur_tasks_head = &cset->tasks;
+ } else if (!list_empty(&cset->mg_tasks)) {
it->task_pos = cset->mg_tasks.next;
- else
+ it->cur_tasks_head = &cset->mg_tasks;
+ } else {
it->task_pos = cset->dying_tasks.next;
+ it->cur_tasks_head = &cset->dying_tasks;
+ }
it->tasks_head = &cset->tasks;
it->mg_tasks_head = &cset->mg_tasks;
@@ -4463,10 +4467,14 @@ repeat:
else
it->task_pos = it->task_pos->next;
- if (it->task_pos == it->tasks_head)
+ if (it->task_pos == it->tasks_head) {
it->task_pos = it->mg_tasks_head->next;
- if (it->task_pos == it->mg_tasks_head)
+ it->cur_tasks_head = it->mg_tasks_head;
+ }
+ if (it->task_pos == it->mg_tasks_head) {
it->task_pos = it->dying_tasks_head->next;
+ it->cur_tasks_head = it->dying_tasks_head;
+ }
if (it->task_pos == it->dying_tasks_head)
css_task_iter_advance_css_set(it);
} else {
@@ -4485,11 +4493,12 @@ repeat:
goto repeat;
/* and dying leaders w/o live member threads */
- if (!atomic_read(&task->signal->live))
+ if (it->cur_tasks_head == it->dying_tasks_head &&
+ !atomic_read(&task->signal->live))
goto repeat;
} else {
/* skip all dying ones */
- if (task->flags & PF_EXITING)
+ if (it->cur_tasks_head == it->dying_tasks_head)
goto repeat;
}
}
@@ -4595,6 +4604,9 @@ static void *cgroup_procs_next(struct seq_file *s, void *v, loff_t *pos)
struct kernfs_open_file *of = s->private;
struct css_task_iter *it = of->priv;
+ if (pos)
+ (*pos)++;
+
return css_task_iter_next(it);
}
@@ -4610,7 +4622,7 @@ static void *__cgroup_procs_start(struct seq_file *s, loff_t *pos,
* from position 0, so we can simply keep iterating on !0 *pos.
*/
if (!it) {
- if (WARN_ON_ONCE((*pos)++))
+ if (WARN_ON_ONCE((*pos)))
return ERR_PTR(-EINVAL);
it = kzalloc(sizeof(*it), GFP_KERNEL);
@@ -4618,10 +4630,11 @@ static void *__cgroup_procs_start(struct seq_file *s, loff_t *pos,
return ERR_PTR(-ENOMEM);
of->priv = it;
css_task_iter_start(&cgrp->self, iter_flags, it);
- } else if (!(*pos)++) {
+ } else if (!(*pos)) {
css_task_iter_end(it);
css_task_iter_start(&cgrp->self, iter_flags, it);
- }
+ } else
+ return it->cur_task;
return cgroup_procs_next(s, NULL, NULL);
}