[patch 09/16] Tracepoint fix disable

[Mathieu Desnoyers]

Set the probe array pointer to NULL when the tracepoint is disabled.
The probe array point not being NULL could generate a race condition where the
reader would dereference a freed pointer.

Impact: bugfix.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
CC: 'Ingo Molnar' <mingo@xxxxxxx>
CC: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
 kernel/tracepoint.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux.trees.git/kernel/tracepoint.c
===================================================================
--- linux.trees.git.orig/kernel/tracepoint.c	2008-11-14 17:39:52.000000000 -0500
+++ linux.trees.git/kernel/tracepoint.c	2008-11-14 17:39:56.000000000 -0500
@@ -262,6 +262,7 @@ static void set_tracepoint(struct tracep
 static void disable_tracepoint(struct tracepoint *elem)
 {
 	elem->state = 0;
+	rcu_assign_pointer(elem->funcs, NULL);
 }
 
 /**

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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