Messages in this thread Patch in this message | | | From | Daniel Bristot de Oliveira <> | Subject | [PATCH V5 12/14] trace: Protect tr->tracing_cpumask with get/put_online_cpus | Date | Tue, 22 Jun 2021 16:42:30 +0200 |
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In preparation to the hotplug support on tracers with workload, protect tr->tracing_cpumask with get/put_online_cpus() to avoid concurrency with hotplug operations.
Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alexandre Chartre <alexandre.chartre@oracle.com> Cc: Clark Willaims <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> --- kernel/trace/trace.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 52fc9438b7b4..c14f33db147e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5053,7 +5053,13 @@ int tracing_set_cpumask(struct trace_array *tr, arch_spin_unlock(&tr->max_lock); local_irq_enable(); + /* + * tracing_cpumask is read by tracers that support CPU + * hotplug. + */ + get_online_cpus(); cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); + put_online_cpus(); return 0; } -- 2.31.1
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