From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-op-o11.zoho.com (sender4-op-o11.zoho.com [136.143.188.11]) (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 44C86480943; Wed, 29 Jul 2026 12:49:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.11 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785329342; cv=pass; b=qeI4kQ9Ol3EYjd7AbcR7NujFhP2u12YD4DHOLe45SNb96XTPVYFERIhDrxbgUIG441laGiVeX/VZcRLQgwPSldsbaoiGVAd5KBugXw6bolRRjyjJ0MvT7cGMLmPfWzv6WiL3r3wIQzC+e0izxHA8WpNWtPh4NI/JSryyhHH75n8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785329342; c=relaxed/simple; bh=K6/3kU8+PyP2xUrEwLEWq6fy9+6Z8w5y2gToAP/crv4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=skBitxKb6iRE7cfE78V/UEGHeICAD83bBqKq+hBAhzu0oASPyFTVcqXlArqy7kyn8LTan0mPTMPJUtriZZblVeQ/H9rzkeKwMd0QG/iLRUSeWYnQLGszgv5mzvBaUImFD41LYVZkQSN9KWOMeJeAfaX8pXXsxdd6DcZDWhwS4JY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=leandro.ribeiro@collabora.com header.b=DFnsJ9Uj; arc=pass smtp.client-ip=136.143.188.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=leandro.ribeiro@collabora.com header.b="DFnsJ9Uj" ARC-Seal: i=1; a=rsa-sha256; t=1785329312; cv=none; d=zohomail.com; s=zohoarc; b=Bujx/lJqLxcSrFvDgB8sLzLAxzVNAYML8stfeYcXTpkJQ7GJ0eF9ZqjK326bN0mvf5lfIcl9Up2E7dedD55pVY2w0g7hKJhWu8g/E64z7/en/9NPIF5dc83fD4qHuXEymZspuqtKvOgGTGACdLMqmG6aKmir1DqCd6qeMmIf1uk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1785329312; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=mBlfFTZEC5TmDbfDkYkor8AyQ5BZ1sJ44q+KZ1cZS1A=; b=hPGekkEgQ/KbZ1oChaMtEt2xSL+7u9I12qK4U6FPJmxD1wU8Q3ujnxgMlDCMEjJd09IL4YUDklt7RenIEje9TKn0vnpRJ3Iy5iTx7iQRwfadmSZgs4VlynK1CJIBNzyea+YzUIcdiu54DKrJ8iNlFu5Jm6ak0W8HDE53W55pFJc= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=leandro.ribeiro@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1785329312; s=zohomail; d=collabora.com; i=leandro.ribeiro@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=mBlfFTZEC5TmDbfDkYkor8AyQ5BZ1sJ44q+KZ1cZS1A=; b=DFnsJ9UjAdjCMoA+gAC4AR2jbYLCSUuPmAWJXewZ/evi6DjsbF6yz9K+dBwzmbtC zBDiY0766nN736vW2EJT79duVMSBYP/63p3KndyfvcPJOZtJzg7HBtT1DnXbR0tHpwP uTgDcq8VttZiCMkq30jic792e97VOATadAW0fBvc= Received: by mx.zohomail.com with SMTPS id 1785329309162762.3161254320859; Wed, 29 Jul 2026 05:48:29 -0700 (PDT) Message-ID: <55f614e1-a016-48ef-b4ec-fe472cb6ed69@collabora.com> Date: Wed, 29 Jul 2026 09:48:22 -0300 Precedence: bulk X-Mailing-List: linux-next@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Policy regarding linux-next only changes To: Tetsuo Handa , Miguel Ojeda Cc: Mark Brown , Pekka Paalanen , Daniel Stone , Theodore Tso , Alexander Potapenko , Christoph Hellwig , Aleksandr Nogikh , Boqun Feng , Gary Guo , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Miguel Ojeda , Linus Torvalds , peterz@infradead.org, will@kernel.org, longman@redhat.com, mingo@kernel.org, gregkh@linuxfoundation.org References: <2c903636-532f-47b5-9894-00470f235682@I-love.SAKURA.ne.jp> <58689827-9211-4f26-9777-51c0b5e1eebb@I-love.SAKURA.ne.jp> <8c3d90d5-747e-451b-bdcb-1cfe1d5fce53@I-love.SAKURA.ne.jp> <0e5ea495-07a2-4f83-8fd7-c90563bc12c4@sirena.org.uk> <43a46fbd-acea-43f6-99f4-c8b866a5f9f4@I-love.SAKURA.ne.jp> Content-Language: en-US From: Leandro Ribeiro In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External On 7/28/26 20:46, Tetsuo Handa wrote: > On 2026/07/29 7:11, Miguel Ojeda wrote: >> On Tue, Jul 28, 2026 at 4:46 PM Tetsuo Handa >> wrote: >>> >>> syzbot stops upon encountering "BUG:" or "WARNING:" within printk() output. >> >> Out of curiosity, is that a fundamental property or something that >> could be optionally be relaxed (for certain linux-next runs only, >> perhaps) so that you can continue testing in certain cases where the >> "WARNING:" may be harmless (i.e. irrelevant for your particular >> fuzzing)? >> >> i.e. I was wondering whether the system could ignore the "WARNING:"s >> (and avoid the kernel panicking on them etc.) until after boot, i.e. >> when the fuzzing starts. > > syzbot uses kernel.panic_on_warn=1, for most of WARN*() users are reporting > problems that should not be ignored. Therefore, WARN*() must not be used for > reporting recoverable mistakes like -EINVAL. Abusing WARN*() like > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/kernel/workqueue.c?id=6e845bcb78c95af935094040bd4edc3c2b6dd784#n5855 > is a fatal barrier for continuous testing systems like syzbot. > > Quoting from https://lkml.kernel.org/r/5b2dea50-2850-4876-b6e8-ba94b9a85034@I-love.SAKURA.ne.jp : > > Please never try to emit WARNING: or BUG: message just for letting developers > update their code. If you can't use panic() instead of WARN*() or BUG*(), you > should not use WARN*() or BUG*(). The patch author who changes the behavior of > in-tree code is responsible for updating all in-tree code. > > Commit 860e748bddcc ("drm: ensure blend mode supported if pixel format > with alpha exposed") must be reverted or updated not to emit "WARNING:" string. > Until authors of that commit respond, that commit had better be excluded from > the linux-next tree. > Hello, First of all, sorry for all the trouble with this warning. I'll propose a patch replacing the warning with printk() or pr_info(), if that doesn't cause similar issues for fuzzers. Thanks, Leandro