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 7462E334C0B; Mon, 29 Dec 2025 16:33:02 +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=1767025983; cv=none; b=vFzuiqqJfA+6k7dhEMbY5Xjw79wN5v/Q8DZMj3ZTigvFTzATUB7JyJF1wI6zHU1JacoCfnFYZRUJoUZprHjSUErDOtsdNdIiAQETsFyM6EW5KTQF0AjyEzX9Ey+4nMv9yvkDoiP77MtBoDhX7pA7U8m88xQgUe9GA1GH08qHTkQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767025983; c=relaxed/simple; bh=CMUK+XtqNJpaqcZha0SVraFf9ag7wTaK5lrw/o0gP30=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u3ttAd59NAV1zK+wIQOC8b2T/FZdtB/SmUBma993x4s5p7MULIjEUUiLNuqyUHveeYnGA1GEBNNx3rKhd4c7UGvD9l19kMLCsHuhNf9xs9pImJBv+NLCeyQnbfVfztagpAtaFDZOHdXwz7UcZQzZ0W5ycZxe+aNSv3HaD2CMrxY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fykGARo1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fykGARo1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3D0CC4CEF7; Mon, 29 Dec 2025 16:33:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767025982; bh=CMUK+XtqNJpaqcZha0SVraFf9ag7wTaK5lrw/o0gP30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fykGARo1ro4FFfLrFgDeFohRzC3Nvafi67jy0QbiKzGg5swQw77YKcRC5Tw/IxiPN A6ja124j5CgA8dFNL2Fwxyr1Ki+lXLHaQdgdH+LaY7yvCXmgrH/OwzsCtfH+uwDDrb /sIYt2+rGrxSTxmGwQLzQlqmgqFk6WZXwf47VFgs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masami Hiramatsu , Mathieu Desnoyers , Douglas Raillard , "Steven Rostedt (Google)" Subject: [PATCH 6.18 405/430] tracing: Fix fixed array of synthetic event Date: Mon, 29 Dec 2025 17:13:27 +0100 Message-ID: <20251229160739.216221205@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251229160724.139406961@linuxfoundation.org> References: <20251229160724.139406961@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt commit 47ef834209e5981f443240d8a8b45bf680df22aa upstream. 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/dynamic_events # echo 'hist:keys=pid:ts=common_timestamp.usecs if !(common_flags & 0x18)' > /sys/kernel/tracing/events/sched/sched_waking/trigger # echo 'hist:keys=next_pid:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,next_comm,$delta)' > /sys/kernel/tracing/events/sched/sched_switch/trigger That caused the output of: -0 [001] d..5. 193.428167: wake_lat: wakee=(efault)sshd-sessiondelta=155 sshd-session-879 [001] d..5. 193.811080: wake_lat: wakee=(efault)kworker/u34:5delta=58 -0 [002] d..5. 193.811198: wake_lat: wakee=(efault)bashdelta=91 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/dynamic_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 synthetic events") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events_synth.c | 1 - 1 file changed, 1 deletion(-) --- 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_eve 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 == se->n_fields - 1 ? "" : " "); n_u64 += STR_VAR_LEN_MAX / sizeof(u64);