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 50C77143C40; Thu, 13 Jun 2024 13:26:48 +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=1718285208; cv=none; b=OTTCrOwwOzxYJw05aRnQIp8sIx97NSPUacBrW1id2NoggJpp0tpdq4Y3sJfBPP/+zJG/eYH8ctyf92XK5VVz4XyHXT6QkGLhZ+U87cxSW9AJ1A35eb+QkNcHn7MmmfY/HC9nYoD6OY1NMWG2bHv6xxLUqq3vi7IVag6HwDjLh8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718285208; c=relaxed/simple; bh=/4UAOu8OPxB6jQeNkyxjOzmqUKJUuZRRJHc/NOgQCGA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VUUuw8sIkm//gPo1CE2Rkj1zuzZ3QZ88tIC/rfa3K5UtUmWjTdP9wbN1kXP63M6ovUPpZ+X2CIyzVO3JnZ7+1RDIOcVJYe+2jGLY/tBxLlaSEezJVcJDluFkaaX0stCW2YVLhoiJmcHSI2hVaP96NA1IA2dbSd7++05rBlsQEYw= 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 5C307C32786; Thu, 13 Jun 2024 13:26:44 +0000 (UTC) Date: Thu, 13 Jun 2024 09:26:42 -0400 From: Steven Rostedt To: Ard Biesheuvel Cc: Mike Rapoport , Kees Cook , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Tony Luck , "Guilherme G. Piccoli" , linux-hardening@vger.kernel.org, Guenter Roeck , Ross Zwisler , wklin@google.com, Vineeth Remanan Pillai , Joel Fernandes , Suleiman Souhlal , Linus Torvalds , Catalin Marinas , Will Deacon Subject: Re: [PATCH v3 2/2] pstore/ramoops: Add ramoops.mem_name= command line option Message-ID: <20240613092642.385461d5@rorschach.local.home> In-Reply-To: References: <20240611144911.327227285@goodmis.org> <20240611144949.703297941@goodmis.org> <202406121145.8860502D7@keescook> <20240612145228.5bf426e0@rorschach.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-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 On Thu, 13 Jun 2024 08:11:48 +0200 Ard Biesheuvel wrote: > > > > I've added one more comment to v5, with that fixed I can take this. > > > > So how is this supposed to work wrt to the rigid 'no user visible > regressions' rule, given that this whole thing is a best effort thing This has nothing to do with user space. The kernel command line has broken in the past. If you update the kernel, you can update the command line. There's no "no user visible regressions" rule. It's "Don't break user space". This has nothing to do with user space. > to begin with. This needs at least a huge disclaimer that this rule > does not apply, and if this works today, there is no guarantee that it > will keep working on newer kernels. Otherwise, you will be making the > job of the people who work on the boot code significantly more > difficult. And even then, I wonder whether Linus and #regzcop are > going to honour such a disclaimer. Again, this has nothing to do with user space. The rule Linus talks about is breaking user space. This is about kernel debugging. Something *completely different*! > > So this belongs downstream, unless some guarantees can be provided > that this functionality is exempt from the usual regression policies. I disagree. kexec/kdump also has the same issues. -- Steve