[PATCH v7 13/18] perf: Skip user unwind if the task is a kernel thread.
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-04-30 20:01:05
Also in:
linux-perf-users, linux-toolchains, lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
From: Josh Poimboeuf <jpoimboe@kernel.org> If the task is not a user thread, there's no user stack to unwind. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> --- 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 430dd158b1ee..ec9edf602974 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c@@ -8101,7 +8101,8 @@ 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