From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F9A82FE368; Thu, 17 Jul 2025 17:33:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752773592; cv=none; b=SNs8MkurAhHziLVJq7Y39EmNJGIkkAU8IbgQYSK0lCRW1Epdz1i0riwNNBBoY1pQFssS1fs9O1L74m9ZJUSKjKJTDgpzq64+uXsLwNcrfEfD25ZLT4+1l6ICw0fWxI8mNb3cRbpiRJNppytxckzy/R1iQZAtyFUiTmr/v2UlCnY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752773592; c=relaxed/simple; bh=PrLV5/6t/jDNDZv13dJ+tk4FMXWbDNxrkHMrhIU764A=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=MgtXYVhczvQWIJBkv5rPWbVGF+dVUtw6fUsJMdUZYYe1WgdYbQgQ8zkxR3U7x7tpVgLLyEX+vu6ErE/9lz6YhKGFkr1S3PbkdyYDz9jIFrbKfxgg0VM1y4+fag7jme9SipSpvEHFJZ1ZnjL7ZHYBt1Wj/55xsyG5NEuIev0dPV4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QMhKkBQ7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QMhKkBQ7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 304D5C4CEED; Thu, 17 Jul 2025 17:33:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752773592; bh=PrLV5/6t/jDNDZv13dJ+tk4FMXWbDNxrkHMrhIU764A=; h=Date:From:To:Cc:Subject:References:From; b=QMhKkBQ7wCz+KWRiWhE3QT9BE3z9z7zT19nsr/tl3qIoptT57DNxI/cR9wif+US7m UrPnsGfJHaa1wS2wMnrOAUzcP5q+9zd8XOzaeNVtI6SLQyn3sfflvwnXVBV6m8BOZx +euu2foBS8A9iSqNOw2wXF9eBikKJ5EwXLFwWyrei8tcmPa7VdUeoM54dNSXZVMLeU WsKju9WlzLqtDO3nWwO9e5KtFk3rveP/YCeqLU37yO3yEPLEyJiFj7fI0P0WeXrinv 0HwIzXcjPnOeu7lVmG5Pw26+HoC8eZaqkN/eSmDgbvt7BBcpQ3LgWwSJ/9yOQ7SpSN 7MG0EkL7+JLmg== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1ucSU9-00000006c0g-42Ag; Thu, 17 Jul 2025 13:33:33 -0400 Message-ID: <20250717173333.809101137@kernel.org> User-Agent: quilt/0.68 Date: Thu, 17 Jul 2025 13:31:30 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: Linus Torvalds , Josh Poimboeuf , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Namhyung Kim , Alexei Starovoitov , Jens Axboe , Masami Hiramatsu , Mathieu Desnoyers , Andrew Morton Subject: [PATCH 5/5] perf: Skip user unwind if the task is a kernel thread References: <20250717173125.434618999@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Josh Poimboeuf 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) --- 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 1fa554e2666d..bd0a33f389d2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8166,7 +8166,8 @@ 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; -- 2.47.2