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 940A7E56A for ; Mon, 16 Dec 2024 01:09:50 +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=1734311390; cv=none; b=AuMSCYdarutIOQFEOYpn3Y3RkwNJJVRIcgYORY3B6HkUBoFjtdsBFkJ2r6geHcQBGOqERCTiQPxIYnuknn+gN24cCXbM8YdtwOszjokF/mGBEj41Yj1Pwv4svBRKrKiqBVKzwrbe5GGY0aX4F0onvjkZ1NJPVRjUcrBnQAQszfU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734311390; c=relaxed/simple; bh=AI3KSgaav8QYd0mzA+A+8meEjDh2HtmAXZ/qd8sM5Bk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=eYL2MQtTT5PUFkdYsQw8gc16WKD4MQX3aPTJ4Ic6Ecr104N1D2JYmxhgnVTGUy37/ZDTsjqDy6SHNGrEw6jLg+GhPCczT5grxjNvMsCAiHdqykSsE+JnClC2ekn1aqSJksalQ5G3lUXyfZvxGKfbErEDTe69JBAxIMKE+ELWVqc= 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 E634EC4CED4; Mon, 16 Dec 2024 01:09:48 +0000 (UTC) Date: Sun, 15 Dec 2024 20:09:50 -0500 From: Steven Rostedt To: "Theodore Ts'o" Cc: Linus Torvalds , LKML , Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Al Viro , Michal Simek Subject: Re: [GIT PULL] ftrace: Fixes for v6.13 Message-ID: <20241215200950.5cb5c3d9@batman.local.home> In-Reply-To: <20241215214034.GE2472262@mit.edu> References: <20241214182138.4e7984a2@batman.local.home> <20241214220403.03a8f5d0@gandalf.local.home> <20241214221212.38cc22c3@gandalf.local.home> <20241214233855.46ad80e0@gandalf.local.home> <20241215050517.050e9d83@gandalf.local.home> <20241215214034.GE2472262@mit.edu> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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=US-ASCII Content-Transfer-Encoding: 7bit [ I'm back from a lovely day with my wife and friends visiting the Finger Lake wineries which I would love to share with the Linux Plumbers attendees if we ever get to have Plumbers at the Ithaca Conference center. ;-) ] On Sun, 15 Dec 2024 16:40:34 -0500 "Theodore Ts'o" wrote: > I'm not convinced that it's worth it in this particular case, so I > think I side with Linus here; maybe all of this hackery isn't worth > it? Steven, what am I missing? Why did we go down this particular > path in the first place? I assume there must have been something that > seemed like a good reason at the time? It has nothing to do with performance. It has only to do with debugging and catching the issue where developers use "%s" in the TP_printk() of TRACE_EVENT() for a string that can be freed after the trace event was executed but before it is read from the ring buffer. I stated in another email that I didn't like this solution when I wrote it, but it was the only solution I could think of to catch this common bug. But I also stated in another email that I think there's another solution that doesn't deal with va_list implementations and should be acceptable by Linus. I'm not against ripping out the code. I agree with Linus that it's a hack, but the hack that caught the bugs early seemed to me worth it at the time. -- Steve