diff options
| author | Song Liu <song@kernel.org> | 2022-02-04 03:40:57 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-02-07 00:37:27 +0300 |
| commit | 5f4e5ce638e6a490b976ade4a40017b40abb2da0 (patch) | |
| tree | e1b716c4008595ffb28775f1357d8da88414befc | |
| parent | 1d9093457b243061a9bba23543c38726e864a643 (diff) | |
| download | linux-5f4e5ce638e6a490b976ade4a40017b40abb2da0.tar.xz | |
perf: Fix list corruption in perf_cgroup_switch()
There's list corruption on cgrp_cpuctx_list. This happens on the
following path:
perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list)
cpu_ctx_sched_in
ctx_sched_in
ctx_pinned_sched_in
merge_sched_in
perf_cgroup_event_disable: remove the event from the list
Use list_for_each_entry_safe() to allow removing an entry during
iteration.
Fixes: 058fe1c0440e ("perf/core: Make cgroup switch visit only cpuctxs with cgroup events")
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220204004057.2961252-1-song@kernel.org
| -rw-r--r-- | kernel/events/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 57c7197838db..6859229497b1 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -839,7 +839,7 @@ static DEFINE_PER_CPU(struct list_head, cgrp_cpuctx_list); */ static void perf_cgroup_switch(struct task_struct *task, int mode) { - struct perf_cpu_context *cpuctx; + struct perf_cpu_context *cpuctx, *tmp; struct list_head *list; unsigned long flags; @@ -850,7 +850,7 @@ static void perf_cgroup_switch(struct task_struct *task, int mode) local_irq_save(flags); list = this_cpu_ptr(&cgrp_cpuctx_list); - list_for_each_entry(cpuctx, list, cgrp_cpuctx_entry) { + list_for_each_entry_safe(cpuctx, tmp, list, cgrp_cpuctx_entry) { WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0); perf_ctx_lock(cpuctx, cpuctx->task_ctx); |