[for-next][PATCH 3/5] tracing: Eliminate double free on failure of allocation on boot up

[Steven Rostedt]

From: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@xxxxxxxxxxx>

If allocation of the max_buffer fails on boot up, the error path will
free both per_cpu data structures from the buffers. With the new redesign
of the code, those structures are freed if allocations failed. That is,
the helper function that allocates the buffers will free the per cpu data
on failure. No need to do it again. In fact, the second free will cause
a bug as the code can not handle a double free.

Link: 20140603042803.27308.30956.stgit@yunodevel">http://lkml.kernel.org/p/20140603042803.27308.30956.stgit@yunodevel

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@xxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 626dbfde5d56..135af323608b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6671,10 +6671,6 @@ __init static int tracer_alloc_buffers(void)
 out_free_temp_buffer:
 	ring_buffer_free(temp_buffer);
 out_free_cpumask:
-	free_percpu(global_trace.trace_buffer.data);
-#ifdef CONFIG_TRACER_MAX_TRACE
-	free_percpu(global_trace.max_buffer.data);
-#endif
 	free_cpumask_var(global_trace.tracing_cpumask);
 out_free_buffer_mask:
 	free_cpumask_var(tracing_buffer_mask);
-- 
2.0.0.rc2


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