[9/9] samples/kretprobe: correctly check for kthreads

Message ID 20190814104131.20190-10-mark.rutland@arm.com
State New
Headers show
Series
  • kthread detection cleanup
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Commit Message

Mark Rutland Aug. 14, 2019, 10:41 a.m.
In general, a non-NULL current->mm doesn't imply that current is a
kthread, as kthreads can install an mm via use_mm(), and so it's
preferable to use is_kthread() to determine whether a thread is a
kthread.

For consistency, let's use is_kthread() here.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
 samples/kprobes/kretprobe_example.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.11.0

Patch

diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index 186315ca88b3..d6e0bf196f0e 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -41,7 +41,7 @@  static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
 	struct my_data *data;
 
-	if (!current->mm)
+	if (is_kthread(current))
 		return 1;	/* Skip kernel threads */
 
 	data = (struct my_data *)ri->data;