From: Josh Poimboeuf Date: Wed, 20 Aug 2025 18:03:43 +0000 (-0400) Subject: perf: Skip user unwind if the task is a kernel thread X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=16ed389227651330879e17bd83d43bd234006722;p=thirdparty%2Fkernel%2Fstable.git perf: Skip user unwind if the task is a kernel thread If the task is not a user thread, there's no user stack to unwind. Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250820180428.930791978@kernel.org --- diff --git a/kernel/events/core.c b/kernel/events/core.c index f880cec0c9809..28de3baff7922 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8198,7 +8198,8 @@ 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 | PF_USER_WORKER)); /* Disallow cross-task user callchains. */ bool crosstask = event->ctx->task && event->ctx->task != current; const u32 max_stack = event->attr.sample_max_stack;