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 4EBB12918C2; Thu, 24 Apr 2025 19:24:17 +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=1745522657; cv=none; b=TgU+KQmFhRfdYz62N1WwaUY1KnAMuPwl8Tl0NpgTIqBASxlyaeYKF9cTmeIgdJCwXUZ95iJcLsxVZ07mkKTF5WVlvL6RQZj1Wug3cagQI3N4BL5W+W3HrZvQZQUIyF6h7HPoPw5evVkSDXaCkG8jF0tv5wHySTCwVZAvA39gxR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745522657; c=relaxed/simple; bh=dywbzU05uYdtOAPyIPR7737vlANMjFHBgRmD6TWEHjs=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=A5YhmHz6Qy9c/BjUS+GP3XLmJcl5nEr1v5wgMnAvmzbuGk5aqg8KmDFxSTZX8HzJayjti+YDQ6jJuyzpQBY5hXqkY//CcS2iT8zLOMkgFJypyGxZyNa7jcX9sjY3yky9E35Dz8Efz3Jq2rWcHs4bL8H7U6P5M0DJgv3yunFSruc= 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 DA519C4CEED; Thu, 24 Apr 2025 19:24:16 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1u82D7-0000000H2QC-0gGT; Thu, 24 Apr 2025 15:26:13 -0400 Message-ID: <20250424192613.014380756@goodmis.org> User-Agent: quilt/0.68 Date: Thu, 24 Apr 2025 15:25:00 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Josh Poimboeuf , x86@kernel.org, Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Indu Bhagat , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org, Jordan Rome , Sam James , Andrii Nakryiko , Jens Remus , Florian Weimer , Andy Lutomirski , Weinan Liu , Blake Jones , Beau Belgrave , "Jose E. Marchesi" , Alexander Aring Subject: [PATCH v5 4/9] tracing: Do not bother getting user space stacktraces for kernel threads References: <20250424192456.851953422@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Steven Rostedt If a user space stacktrace is requested when running a kernel thread, just return, as there's no point trying to get the user space stacktrace as there is no user space. Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8ddf6b17215c..523e98cd121d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3087,6 +3087,10 @@ ftrace_trace_userstack(struct trace_array *tr, if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE)) return; + /* No point doing user space stacktraces on kernel threads */ + if (current->flags & PF_KTHREAD) + return; + /* * NMIs can not handle page faults, even with fix ups. * The save user stack can (and often does) fault. -- 2.47.2