From cee010ec5211b96f33c5c2208f5c14ebb04b634a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 10 Sep 2010 12:51:54 +0200 Subject: [PATCH] perf: Ensure we call add_event_to_ctx() with the right locks held Even though we call it from the inherit path, where the child is not yet accessible, we need to hold ctx->lock, add_event_to_ctx() assumes IRQs are disabled. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index eaf1c5de6dcc..f395fb4d9b74 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -5913,6 +5913,7 @@ inherit_event(struct perf_event *parent_event, struct perf_event_context *child_ctx) { struct perf_event *child_event; + unsigned long flags; /* * Instead of creating recursive hierarchies of events, @@ -5957,7 +5958,9 @@ inherit_event(struct perf_event *parent_event, /* * Link it up in the child's context: */ + raw_spin_lock_irqsave(&child_ctx->lock, flags); add_event_to_ctx(child_event, child_ctx); + raw_spin_unlock_irqrestore(&child_ctx->lock, flags); /* * Get a reference to the parent filp - we will fput it -- 2.20.1