From nobody Tue Oct 7 21:42:22 2025 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 31C8D242D64; Fri, 9 May 2025 16:51:41 +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=1746809501; cv=none; b=PiruhN4iBZW2HL9ePULIuBTreZ5dhVo70Rf0VHhdSjankklfg6dXSfOkScerVSCPFK3eeRlBR42wTbt+Kmlf8dcwkBEjS+zdwJxFALTYuz/epvdT3uWXS8rl3x+JMg98oZxf93otWrg1PwcsJGkKNoB4vW/F8B2K7T85mXgAs8Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746809501; c=relaxed/simple; bh=kJ1lRlKcjudXfNQvt0hTUNRiwuzXdk/8XeV3RVZQ1LI=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=Z3NLcKGucNsQ297J8VkZ+K49F74c4nPtDOkddRZ4rEjj8qSgi8IxxIpzhEYr+lB1F5T2jNrv1WIFqqckJMZdjIW8R4d8/zsHbOsoxzrF1hOkPXf+ShCnzbRbp0SBSU1ivFtxrLCiytNnC3vxJHt9hrx2wEixyHCHMs2cd+qqzSQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11472C4CEF5; Fri, 9 May 2025 16:51:41 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uDQx2-00000002gMD-3K0A; Fri, 09 May 2025 12:51:56 -0400 Message-ID: <20250509165156.644117342@goodmis.org> User-Agent: quilt/0.68 Date: Fri, 09 May 2025 12:45:42 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org Cc: Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Peter Zijlstra , Ingo Molnar , Jiri Olsa , Namhyung Kim Subject: [PATCH v8 18/18] perf: Skip user unwind if the task is a kernel thread References: <20250509164524.448387100@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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 7c7d5a27c568..02e52df7a02e 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 =3D !event->attr.exclude_callchain_kernel; - bool user =3D !event->attr.exclude_callchain_user; + bool user =3D !event->attr.exclude_callchain_user && + !(current->flags & PF_KTHREAD); /* Disallow cross-task user callchains. */ bool crosstask =3D event->ctx->task && event->ctx->task !=3D current; const u32 max_stack =3D event->attr.sample_max_stack; --=20 2.47.2