oprofile: fix CPU unplug panic in ppro_stop()

If oprofile statically compiled in kernel, a cpu unplug triggers a panic in ppro_stop(), because a NULL pointer is dereferenced. Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: Robert Richter <[email protected]>
hanmiltonxing · Dec 3, 2008 · 9ea84ad · 9ea84ad
1 parent 061e41f
commit 9ea84ad
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c
@@ -156,6 +156,8 @@ static void ppro_start(struct op_msrs const * const msrs)
 	unsigned int low, high;
 	int i;
 
+	if (!reset_value)
+		return;
 	for (i = 0; i < num_counters; ++i) {
 		if (reset_value[i]) {
 			CTRL_READ(low, high, msrs, i);
@@ -171,6 +173,8 @@ static void ppro_stop(struct op_msrs const * const msrs)
 	unsigned int low, high;
 	int i;
 
+	if (!reset_value)
+		return;
 	for (i = 0; i < num_counters; ++i) {
 		if (!reset_value[i])
 			continue;