- Prevent cgroup event list corruption when switching events

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Merge tag 'perf_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fix from Borislav Petkov:
 "Prevent cgroup event list corruption when switching events"

* tag 'perf_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix list corruption in perf_cgroup_switch()
This commit is contained in:
Linus Torvalds 2022-02-13 09:25:26 -08:00
commit f5e02656b1

View file

@ -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);