On Wed, 2013-04-10 at 09:18 +0900, Namhyung Kim wrote:From: Namhyung Kim <namhyung.kim@xxxxxxx>
It looks like tracing_release() lacks checking iter->cpu_file so that
closing a per_cpu trace file would attempt to close all cpu buffers.
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
kernel/trace/trace.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7270460cfe3c..0beddcb80509 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2883,7 +2883,13 @@ static int tracing_release(struct inode *inode, struct file *file)
WARN_ON(!tr->ref);
tr->ref--;
- for_each_tracing_cpu(cpu) {
+ if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
Only the cpu that is assigned gets buffer_iter[cpu] set. The other
buffer_iter[cpus] will simply be ignored.