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 718552475C7 for ; Thu, 17 Apr 2025 12:27:39 +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=1744892859; cv=none; b=TkkgxgK5hDocY9KdAhjd02QgQUTCcfWflkq493w1LzHQgoo2ut0zBl5jYej3mPnnAH8i7m3FjtGOpELmfwmBNMc8f629my4UzTSqoPj6/mqJwV8hc2Pdx/mcvvTQ3gtPS8WvxGmjb0/cIPFgDYnqKLmNuP9kjI/EM60cc62aCfU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744892859; c=relaxed/simple; bh=O2PTo4z16pETZyZkspQt7nTynp4C6/OsX+smrDwitMo=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=iHFesgdE3knGY3Jx6r9jvuskCpfupSix+fKV91mPV5XmD+v7Hkfk1RL52qryI1YVxVuuKf1BcgOHKeIE/W9dfY0K1NQURsJWtKtUSYnPtv7874fv/mBPS35owvf0kKvPQ/ffvUmeTMuHDcD1pAoeQssycK8p16B4AV0fvdWJcoo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lVcF08xp; 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="lVcF08xp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAF87C4CEEF; Thu, 17 Apr 2025 12:27:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744892859; bh=O2PTo4z16pETZyZkspQt7nTynp4C6/OsX+smrDwitMo=; h=Subject:To:Cc:From:Date:From; b=lVcF08xpYZ7gKUAXxMqTuuShNSrhFHYtBG2/fC7utbSQlRC7/q8G8G1vfIXf8o8B9 /NcX46U5KeZI4WPKhOxBnClC9fwumKlS9nahM7AIe7ZSWId7Gyazh8P2y7EvSkcrgj 5Nnt19JomvzMEvxOEABBSFPI5a+ixta01IoGAp8Q= Subject: FAILED: patch "[PATCH] tracing: Do not add length to print format in synthetic" failed to apply to 6.1-stable tree To: rostedt@goodmis.org,douglas.raillard@arm.com,mathieu.desnoyers@efficios.com,mhiramat@kernel.org,zanussi@kernel.org Cc: From: Date: Thu, 17 Apr 2025 14:26:06 +0200 Message-ID: <2025041706-ambiance-zen-5f4e@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x e1a453a57bc76be678bd746f84e3d73f378a9511 # git commit -s git send-email --to '' --in-reply-to '2025041706-ambiance-zen-5f4e@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From e1a453a57bc76be678bd746f84e3d73f378a9511 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 7 Apr 2025 15:41:39 -0400 Subject: [PATCH] tracing: Do not add length to print format in synthetic events The following causes a vsnprintf fault: # 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 Because the synthetic event's "wakee" field is created as a dynamic string (even though the string copied is not). The print format to print the dynamic string changed from "%*s" to "%s" because another location (__set_synth_event_print_fmt()) exported this to user space, and user space did not need that. But it is still used in print_synth_event(), and the output looks like: -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 bash-880 [002] d..5. 193.811371: wake_lat: wakee=(efault)kworker/u35:2delta=21 -0 [001] d..5. 193.811516: wake_lat: wakee=(efault)sshd-sessiondelta=129 sshd-session-879 [001] d..5. 193.967576: wake_lat: wakee=(efault)kworker/u34:5delta=50 The length isn't needed as the string is always nul terminated. Just print the string and not add the length (which was hard coded to the max string length anyway). Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers Cc: Tom Zanussi Cc: Douglas Raillard Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/20250407154139.69955768@gandalf.local.home Fixes: 4d38328eb442d ("tracing: Fix synth event printk format for str fields"); Signed-off-by: Steven Rostedt (Google) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 969f48742d72..33cfbd4ed76d 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -370,7 +370,6 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter, union trace_synth_field *data = &entry->fields[n_u64]; trace_seq_printf(s, print_fmt, se->fields[i]->name, - STR_VAR_LEN_MAX, (char *)entry + data->as_dynamic.offset, i == se->n_fields - 1 ? "" : " "); n_u64++;