From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
If the task is not a user thread, there's no user stack to unwind.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/events/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 375115492c02..55d5d4ded7ab 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8144,7 +8144,8 @@ struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
bool kernel = !event->attr.exclude_callchain_kernel;
- bool user = !event->attr.exclude_callchain_user;
+ bool user = !event->attr.exclude_callchain_user &&
+ !(current->flags & PF_KTHREAD);
/* Disallow cross-task user callchains. */
bool crosstask = event->ctx->task && event->ctx->task != current;
const u32 max_stack = event->attr.sample_max_stack;
--
2.47.2
