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perf: Really fix event_function_call() locking

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BugLink: https://bugs.launchpad.net/bugs/2089884

[ Upstream commit fe826cc2654e8561b64246325e6a51b62bf2488c ]

Commit 558abc7e3f89 ("perf: Fix event_function_call() locking") lost
IRQ disabling by mistake.

Fixes: 558abc7e3f89 ("perf: Fix event_function_call() locking")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
This commit is contained in:
Namhyung Kim
2024-08-13 22:55:11 +02:00
committed by Mehmet Basaran
parent 6230788ff5
commit cfe259e0fb
1 changed files with 8 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/events/core.c
+8 -5
View File
@@ -263,8 +263,8 @@ unlock:
static void event_function_call(struct perf_event *event, event_f func, void *data)
{
struct perf_event_context *ctx = event->ctx;
struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
struct perf_cpu_context *cpuctx;
struct event_function_struct efs = {
.event = event,
.func = func,
@@ -292,22 +292,25 @@ again:
if (!task_function_call(task, event_function, &efs))
return;
local_irq_disable();
cpuctx = this_cpu_ptr(&perf_cpu_context);
perf_ctx_lock(cpuctx, ctx);
/*
* Reload the task pointer, it might have been changed by
* a concurrent perf_event_context_sched_out().
*/
task = ctx->task;
if (task == TASK_TOMBSTONE) {
perf_ctx_unlock(cpuctx, ctx);
return;
}
if (task == TASK_TOMBSTONE)
goto unlock;
if (ctx->is_active) {
perf_ctx_unlock(cpuctx, ctx);
local_irq_enable();
goto again;
}
func(event, NULL, ctx, data);
unlock:
perf_ctx_unlock(cpuctx, ctx);
local_irq_enable();
}
/*