From e7d0bc047548d76feee6b23f7d3d9da927189a50 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Thu, 14 Oct 2010 16:54:51 +0200
Subject: [PATCH] perf: Fix task refcount bugs
Currently it looks like find_lively_task_by_vpid() takes a task ref
and relies on find_get_context() to drop it.
The problem is that perf_event_create_kernel_counter() shouldn't be
dropping task refs.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
LKML-Reference: <20101014203625.278436085@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/perf_event.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 346dc0e35a0abf..f928878a1c17c1 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2190,11 +2190,9 @@ retry:
}
}
- put_task_struct(task);
return ctx;
errout:
- put_task_struct(task);
return ERR_PTR(err);
}
@@ -5602,7 +5600,7 @@ SYSCALL_DEFINE5(perf_event_open,
ctx = find_get_context(pmu, task, cpu);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
- goto err_group_fd;
+ goto err_task;
}
/*
@@ -5698,6 +5696,9 @@ SYSCALL_DEFINE5(perf_event_open,
err_context:
put_ctx(ctx);
+err_task:
+ if (task)
+ put_task_struct(task);
err_group_fd:
fput_light(group_file, fput_needed);
free_event(event);
--
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