From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (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 B81DD286D55 for ; Wed, 8 Oct 2025 13:48:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759931332; cv=none; b=UTceK4wVZj8YE/IPD3IOLFzXBgkfoILDSeHdzK4GlKdnLRzNP75d4TXfDYypjK4VzPMSxNOmwF2lgIdCeCNvOQzAo+nKlbV1glwvYIjz80Z4L6JR9u8mL6cu8QoryfkyenH9pFoBPESMd5wKW5EPRm40VGfGFXeICK+eSoOLO8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759931332; c=relaxed/simple; bh=GbSaa/EKZ5s8UkgtPrh/MX8WgMkQZPaiA6bJfdaGpgw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=I48eHPvQl8Zzg4UvOfBJTf706CgsiJMXuEejSmrCiGPJVdThdOTPaGOZeL+ixV8yzUSIpVHkCBQYSWV4+qtz+TYRcTQg8vmxCx+oYbni9xzWLk8eY9RE5JRBBs6jDWsgELUZokLPfiwaTiXm/Vl1OchmZW4FzeIiiS25A0lNb8Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XN18ZBQH; arc=none smtp.client-ip=91.218.175.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XN18ZBQH" Message-ID: <3fa8182f-0195-43ee-b163-f908a9e2cba3@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1759931325; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Uf5/duJrWVKUCDJFgAcXUExHgRsL5XyYj1G/kjKoQGw=; b=XN18ZBQHkL8VF42r5TRMQE022lIyv/4biRi92DxLzr+OwHWrQo1lBg7HW2YB6owPNKY/AP h3sdwVABCXdpNWT92wcOEWaDCwUIs7coRdTd6DNumvRABDWHVg3NmTg3WWMQ3spQWmrow/ /rU1jTQvLss0mVrtlzpXkiR37xDte28= Date: Wed, 8 Oct 2025 21:48:36 +0800 Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2 1/1] hung_task: fix warnings caused by unaligned lock pointers Content-Language: en-US To: Finn Thain , Andrew Morton Cc: Geert Uytterhoeven , Eero Tamminen , Kent Overstreet , amaindex@outlook.com, anna.schumaker@oracle.com, boqun.feng@gmail.com, ioworker0@gmail.com, joel.granados@kernel.org, jstultz@google.com, leonylgao@tencent.com, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, longman@redhat.com, mhiramat@kernel.org, mingo@redhat.com, mingzhe.yang@ly.com, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, tfiga@chromium.org, will@kernel.org, stable@vger.kernel.org References: <20250909145243.17119-1-lance.yang@linux.dev> <99410857-0e72-23e4-c60f-dea96427b85a@linux-m68k.org> <20251007135600.6fc4a031c60b1384dffaead1@linux-foundation.org> <56784853-b653-4587-b850-b03359306366@linux.dev> <693a62e0-a2b5-113b-d5d9-ffb7f2521d6c@linux-m68k.org> <23b67f9d-20ff-4302-810c-bf2d77c52c63@linux.dev> <2bd2c4a8-456e-426a-aece-6d21afe80643@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 2025/10/8 18:12, Finn Thain wrote: > > On Wed, 8 Oct 2025, Lance Yang wrote: > >> >> In other words, we are not just fixing the bug reported by Eero and >> Geert, but correcting the blocker tracking mechanism's flawed assumption >> for -stable ;) >> >> If you feel this doesn't qualify as a fix, I can change the Fixes: tag >> to point to the original commit that introduced this flawed mechanism >> instead. >> > > That's really a question for the bug reporters. I don't personally have a > problem with CONFIG_DETECT_HUNG_TASK_BLOCKER so I can't say whether the > fix meets the requirements set in > Documentation/process/stable-kernel-rules.rst. And I still don't know I'm a bit confused, as I recall you previously stating that "It's wrong and should be fixed"[1]. To clarify, is your current position that it should be fixed in general, but the fix should not be backported to -stable? If so, then I have nothing further to add to this thread and am happy to let the maintainer @Andrew decide. > what's meant by "unnecessary warnings in a few unexpected cases". The blocker tracking mechanism will trigger a warning when it encounters any unaligned lock pointer (e.g., from a packed struct). I don't think that is the expected behavior. Instead, it should simply skip any unaligned pointer it cannot handle. For the stable kernels, at least, this is the correct behavior. [1] https://lore.kernel.org/lkml/6ec95c3f-365b-e352-301b-94ab3d8af73c@linux-m68k.org/