From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 457FCCCF9F8 for ; Wed, 5 Nov 2025 23:57:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1BBBC8E0005; Wed, 5 Nov 2025 18:57:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 193C78E0003; Wed, 5 Nov 2025 18:57:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F7E88E0005; Wed, 5 Nov 2025 18:57:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 004B98E0003 for ; Wed, 5 Nov 2025 18:57:56 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id A40B11604E7 for ; Wed, 5 Nov 2025 23:57:56 +0000 (UTC) X-FDA: 84078218952.27.C361F00 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf30.hostedemail.com (Postfix) with ESMTP id F1B4080010 for ; Wed, 5 Nov 2025 23:57:54 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=JmhHw+Tm; dmarc=none; spf=pass (imf30.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762387075; a=rsa-sha256; cv=none; b=sgvHZjnUk26iVlBQMr+QF9qWETzQVJRU2RE9muF/dpeh1Q//Q9NzJTEn0gEwhNv4IF5Ue6 TIzK4Y7LQ9ePxFkhSCeT3wRhi4cOrMjPrEcNon6mTaawdMK4GB0gUA0M+uitynPEfCE9el tNrlCJoPWCV2g81M+5mfEzPXM0J/Cm0= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=JmhHw+Tm; dmarc=none; spf=pass (imf30.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762387075; h=from:from:sender: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:dkim-signature; bh=Y+htYTo9KW5vmSLnBQ1+nT1mEEZoMYC6ZICdoQxeSOo=; b=D6G5cjnwbkgw3m1mWr/PdKdrt6Tv24RrctNEhAtZxkYCHD8LtGJdUcVxS/coIadYbH3gjU /OXUlHbdiX9xsjHmBVKxA+NWQ+ng1STLuRt+LJIAAOAYpQTMurFo1HC6IWJTl6dQ93dh5h CGZeF6ZYUmc/J+z5vaQPeAvWKlZlO6A= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 2B81160222; Wed, 5 Nov 2025 23:57:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68760C4CEF5; Wed, 5 Nov 2025 23:57:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1762387073; bh=2Y3mQFTXDjBIqGVv4+kIDxm2f6jAQbNAnGy7he78Hts=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=JmhHw+TmiZ0zvjghAeXmox4sDcO/3+eSl2QW8OHdnfRmWJH6i/l+yb+rvx/TZKerN CHU/H+43D/+hM0VrHf9mxhTR9KZ6oaQFsnaYQ8tYxHllE4XkNxaUSpL950mH1vf7NP +dyRxJGUsHAKLbwgNVrgSfxL0baSDJuz6xov0xUw= Date: Wed, 5 Nov 2025 15:57:52 -0800 From: Andrew Morton To: Zi Yan Cc: David Hildenbrand , Wei Yang , Lorenzo Stoakes , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] mm/huge_memory: fix folio split check for anon folios in swapcache. Message-Id: <20251105155752.fabace52f503424c64517735@linux-foundation.org> In-Reply-To: <20251105162910.752266-1-ziy@nvidia.com> References: <20251105162910.752266-1-ziy@nvidia.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: F1B4080010 X-Rspamd-Server: rspam07 X-Stat-Signature: j9mk7iyh5sjw5kgms8stss7fjj43ta81 X-Rspam-User: X-HE-Tag: 1762387074-377840 X-HE-Meta: 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 ba5TEni9 pCH1H4bKr9bYy5FWmKfvGFWGf5U/qFzht5gTPHYVrG1fNcopGeSqZM99uGidYqrO1xfXxPfhNBWx5BzlpEKa280vWh819xkUU39uhiOU/pSVwOL/ht5MCYsD3qGz/rRI2rRHVoqIurmujl6axRgXHcoxK3BvguFZ/JWxphbofxWdwD0YmsEFvgVrvo9T2tv0LzGSrgh9tc2L9mC4gnceltadA0/kdt+zDO4Twgo/Cw/uYo0gF26qlub1GWd+21+qHt4No8eExwZaCk5Qx5ov4JbzFAE/GjoSlWIbz6UHSy1WyhbcZTEPPFef1BvqhIjJY/QFtkOlQBS0kkxuf6C7DbYk0GaDq4hjv67Vf1h/mvSAoMTwaJxauhEiu4+tX1DD4TlH3624VpxqEYSGSvAzfYXFCmyVUEHafIfon X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 5 Nov 2025 11:29:10 -0500 Zi Yan wrote: > Both uniform and non uniform split check missed the check to prevent > splitting anon folios in swapcache to non-zero order. Fix the check. Please describe the possible userspace-visible effects of the bug especially when proposing a -stable backport. > Fixes: 58729c04cf10 ("mm/huge_memory: add buddy allocator like (non-uniform) folio_split()") > Reported-by: "David Hildenbrand (Red Hat)" > Closes: https://lore.kernel.org/all/dc0ecc2c-4089-484f-917f-920fdca4c898@kernel.org/ I was hopeful, but that's "from code inspection". > Cc: stable@vger.kernel.org > Signed-off-by: Zi Yan