From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2CF634398F4 for ; Thu, 30 Jul 2026 14:04:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785420259; cv=none; b=FZqQoKSddBZwB5uD9JmhV2XSZbvwjqd3AvpW+Cg12p4ICxhXDwZaRE5I96V+CRb1Jur22STHB7ydBOBDNPgJMrKaDeDHNLw4aIpVDpK1ZpW44gMF2Tqg3JZcEVMgkOD5U8qlQWVaeQIyURj8wJGqsx/EBx2PBjUSY29Y89NNB/4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785420259; c=relaxed/simple; bh=DEqxJ5X27WZx4zHTbcG/0t+yyTiDop0aw/ND78hZYJo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Z4MH2kzaXiUfYHyoxvr1lxud+oSZlQrqKI0m8pbsF+KctQrd0TjMntyUTIpOc0zbkiOPmsIafaIrBn0Etafz6zzJn/vd+0smx6mUIIq1V5gF+FJhoPjj2BNTmpWe3zsaXu9ONbPJlxj1+odBGQySR6djxaFKFRg5zDtkJN6Yjuo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A9kppZGM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="A9kppZGM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 492C81F000E9; Thu, 30 Jul 2026 14:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785420257; bh=Sc9xPAqFWs3rxpzHpDrswg/F94fu2SpvgRmyO3t56CM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=A9kppZGM7MB3y8nY4TySZN28Z4Ci/r9XB5Tx5JRC+aUN3yEFxeig8wLrOhhOviS/F HSSC3bJyoYiucxnE+h8iJL/KshDdj/5PYEVGRHZGyLG3R6NaekOrea8X2GchKaQALx DsncTL+WW6EGLxNHf3wt7Ln93wOoaOVEULqCTvI0= Date: Thu, 30 Jul 2026 16:04:03 +0200 From: Greg Kroah-Hartman To: Christoph Hellwig Cc: Keith Busch , Hari Mishal , Jens Axboe , Sagi Grimberg , Hannes Reinecke , Kanchan Joshi , Nitesh Shetty , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] nvme: drop WARN_ON_ONCE on write_stream bounds check Message-ID: <2026073049-improper-paparazzi-6be7@gregkh> References: <20260725135111.14041-3-harimishal1@gmail.com> <2026072748-unpopular-onlooker-4a2b@gregkh> <2026072849-uproar-aqua-07c3@gregkh> <20260728051838.GA20593@lst.de> <2026072834-buffoon-entwine-ed16@gregkh> <20260730114123.GB25956@lst.de> <2026073003-primp-granular-c176@gregkh> <20260730133726.GA2983@lst.de> 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-Disposition: inline In-Reply-To: <20260730133726.GA2983@lst.de> On Thu, Jul 30, 2026 at 03:37:26PM +0200, Christoph Hellwig wrote: > On Thu, Jul 30, 2026 at 03:18:21PM +0200, Greg Kroah-Hartman wrote: > > On Thu, Jul 30, 2026 at 01:41:23PM +0200, Christoph Hellwig wrote: > > > On Tue, Jul 28, 2026 at 08:58:00AM +0200, Greg Kroah-Hartman wrote: > > > [... monster quote mostly dropped, please stick mail netiquette] > > > > > but a debug setup you get what you pay for, and I'm really tired of > > > > > all these totally stupid attempts to make WARN_ON the new BUG_ON. > > > > > It is not, and that's for a reason. > > > > > > > > I'm tired of it too, but again, if this can be hit by something a user > > > > does, it ends up being a DoS on the machine :( > > > > > > So let's kill parnic_on_warn? Or tain the kernel when it is set so > > > that anyone enaling it knows they have to keep the pieces when it > > > breaks? > > > > I know why the cloud-boxes want panic-on-warn enabled, as they are > > cattle and want any potential problem to just reboot the box and keep on > > going. And Samsung likes it for their billions of devices for the same > > reason (it's "safe" to reboot a phone I guess...) > > > > So as much as I would _love_ to drop it, we seem to have real users. > > Then at least add a taint to make it clear to them that they are > getting themselves into trouble instead of trying taking the only > useful debug tool away because of bad choices of a few. > syzbot has this same issue, if it ever hits a WARN() output, it stops and spits out a report. See the long thread on linux-next about this right now for a more recent discussion about this. As for a taint, I'm not sure what you are asking here. If panic-on-warn is not enabled, wonderful, a WARN() will spit out a great debugging message and everyone moves on just fine. It's only the systems that have panic-on-warn enabled that need to worry about user-triggered calls to that macro, and those systems know what they are getting themselves into, including the huge number of CVE fixes they then need to be responsible for backporting :) thanks, greg k-h