From nobody Fri Dec 19 14:44:43 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 CF6BC21CC68; Sat, 6 Dec 2025 01:05:52 +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=1764983152; cv=none; b=k1ks5wRQPtaadjPv9ibnhdQ+2+xu8FooWiei0DJb59xk9nFH8ZDKtacLl/9YBfYGvIzPekskgNTkgKEs1f5FY9BpQ7jNDxgcF9bd9/DzruOcRd2Zjf0OWJrEr3raBGJEoObZgCMZobdKuYeICHecTdAnjMDU7f95A1eLFct0qC8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764983152; c=relaxed/simple; bh=XziP3BZvKCUwzNrgPVp+a4VK1kBazIplv/7b3TjByT0=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=dQ9bFI08d+H3YrbsDZUb35OPP70Q8U1e6KIkPezV/ZN7vc6T2ue0/dW5/nZ3VkIFtSGPu/mvlEWRBzA0Wa+vU5PgpiXyuRX6WTivYPLZmzybl2AEza9tVToHrOpKcjEBuUV9nsNAw+dhMPqAVQ1pVYHj1+lNIFYlBbaRpWMukdo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TVKTJc7t; 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="TVKTJc7t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 878A3C19421; Sat, 6 Dec 2025 01:05:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764983152; bh=XziP3BZvKCUwzNrgPVp+a4VK1kBazIplv/7b3TjByT0=; h=Date:From:To:Cc:Subject:References:From; b=TVKTJc7tS1LNfRyV3wB1vRszmFyK1qX8KnEfHi03XeKM0ZmkP1Gy/pjVHDHpUxiFi 0vwqee4TWk+WpsByfkjDwPMsIeAfv0Vlx62yYeDZwTIAqEV0ItQnAikLNjUllMdFf6 g8jncTAJy5Qjg2A/sFzr+e5hIRSorVlgtqGiwLnu1xu3Q3WxnXE6ln5MGoNRXJOqaa iwOMVqM+3jiQnhDDaAMKZpUOl0+5r0xrVVrP6PAWzOZB14QpXKQqgubrwD2q6sNuLU +V8hqrriAl4Lz7JNqLDomYdkcBrk4baSUDkNyVKmsn3r8l0P3hVdUgGNwrj6lBX6mg 0plsdi4joMjtQ== Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1vRglJ-00000009Vlx-0XCw; Fri, 05 Dec 2025 20:07:01 -0500 Message-ID: <20251206010700.980966840@kernel.org> User-Agent: quilt/0.68 Date: Fri, 05 Dec 2025 20:06:35 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org, Douglas Raillard Subject: [for-linus][PATCH 02/15] tracing: Fix fixed array of synthetic event References: <20251206010633.884804695@kernel.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: Steven Rostedt The commit 4d38328eb442d ("tracing: Fix synth event printk format for str fields") replaced "%.*s" with "%s" but missed removing the number size of the dynamic and static strings. The commit e1a453a57bc7 ("tracing: Do not add length to print format in synthetic events") fixed the dynamic part but did not fix the static part. That is, with the commands: # echo 's:wake_lat char[] wakee; u64 delta;' >> /sys/kernel/tracing/dynam= ic_events # echo 'hist:keys=3Dpid:ts=3Dcommon_timestamp.usecs if !(common_flags & 0= x18)' > /sys/kernel/tracing/events/sched/sched_waking/trigger # echo 'hist:keys=3Dnext_pid:delta=3Dcommon_timestamp.usecs-$ts:onmatch(s= ched.sched_waking).trace(wake_lat,next_comm,$delta)' > /sys/kernel/tracing/= events/sched/sched_switch/trigger That caused the output of: -0 [001] d..5. 193.428167: wake_lat: wakee=3D(efaul= t)sshd-sessiondelta=3D155 sshd-session-879 [001] d..5. 193.811080: wake_lat: wakee=3D(efaul= t)kworker/u34:5delta=3D58 -0 [002] d..5. 193.811198: wake_lat: wakee=3D(efaul= t)bashdelta=3D91 The commit e1a453a57bc7 fixed the part where the synthetic event had "char[] wakee". But if one were to replace that with a static size string: # echo 's:wake_lat char[16] wakee; u64 delta;' >> /sys/kernel/tracing/dyn= amic_events Where "wakee" is defined as "char[16]" and not "char[]" making it a static size, the code triggered the "(efaul)" again. Remove the added STR_VAR_LEN_MAX size as the string is still going to be nul terminated. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Douglas Raillard Link: https://patch.msgid.link/20251204151935.5fa30355@gandalf.local.home Fixes: e1a453a57bc7 ("tracing: Do not add length to print format in synthet= ic events") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_synth.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_= synth.c index 2f19bbe73d27..4554c458b78c 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -375,7 +375,6 @@ static enum print_line_t print_synth_event(struct trace= _iterator *iter, n_u64++; } else { trace_seq_printf(s, print_fmt, se->fields[i]->name, - STR_VAR_LEN_MAX, (char *)&entry->fields[n_u64].as_u64, i =3D=3D se->n_fields - 1 ? "" : " "); n_u64 +=3D STR_VAR_LEN_MAX / sizeof(u64); --=20 2.51.0