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 48481CA0EED for ; Fri, 22 Aug 2025 17:09:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E48F440158; Fri, 22 Aug 2025 13:09:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8912D8E009D; Fri, 22 Aug 2025 13:09:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 66E9C440158; Fri, 22 Aug 2025 13:09:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 459718E009D for ; Fri, 22 Aug 2025 13:09:56 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 116DBB6BD5 for ; Fri, 22 Aug 2025 17:09:56 +0000 (UTC) X-FDA: 83805030792.20.1C70151 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf07.hostedemail.com (Postfix) with ESMTP id 702E64000B for ; Fri, 22 Aug 2025 17:09:54 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=DmWBU4Vz; spf=pass (imf07.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1755882594; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=NJaCLxCq3XCnWLFFwVYzAYFNIZQDOhDO2V5KPJHlnOY=; b=3OMu8jD6pjdWT/N8ejPzdCMW2ow39BFJS53k1Jf03+EfGgb1XlcEDU7G7tqPPeQ+EPwmFC Qx/JUyb45d9INypP8ZF0McdCGIevo8e20NfcBgOJwNH1zC81iVQGYbeBgaTIPv3mdumOk7 3VW+AhsJyA+JS2tYEbeQtJ3lTJsCBWE= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=DmWBU4Vz; spf=pass (imf07.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1755882594; a=rsa-sha256; cv=none; b=OyM0I5Ehkv2gnO/YXKFM9TTFL9iu02rjY/nmviXpyzvWeqxQbbEYCEfE+4QUzoPM8HcCEJ byzI7OPbbbO9EcLr5cBwPJxgmmXxj6IyzHdUXk27lOeBQTUAVUsOHjEkjwXp/n0j/PqTsP S0ORCPJaeqKyx+6097TdKyuFEtuKQH8= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id BE2F160203; Fri, 22 Aug 2025 17:09:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 506C3C4CEED; Fri, 22 Aug 2025 17:09:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755882593; bh=NEyazjWgDDK3Y8sTMLiPKtOTS94IEzEQJlr1MXdW648=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DmWBU4VzSCcAnl6Zdrhjx6ksjldQdRyRt8SGGJHoy1Xwe7M0wFFiAnOgc7AY/DT0q lyqL/1TbY9lw6Mk6ofMnsxQa0R5tG+ekC6WUSLcyfnxUCURU/dBA0VxXY7c6IJ9LBi dspILvQPKUlPvqhEvwNtu+fRhuKR7/IUmABwpf10OfXceruEb+htOjuVlClrNaqJfU QZNtMHJYtlsQdWeTBL2WlQglN7zceCD+RoTlZDKPvwA5Fz0NZs4QmCTFXTFDq7ZuUg eXWdY/p99/aQ44iT5rRcus/JttgHgvk0uE55mO5Gfzz0M9Zot8coHQnhPz2Tn/edlI y9z5UNwm6HZrw== From: SeongJae Park To: David Hildenbrand Cc: SeongJae Park , linux-kernel@vger.kernel.org, Alexander Potapenko , Andrew Morton , Brendan Jackman , Christoph Lameter , Dennis Zhou , Dmitry Vyukov , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, iommu@lists.linux.dev, io-uring@vger.kernel.org, Jason Gunthorpe , Jens Axboe , Johannes Weiner , John Hubbard , kasan-dev@googlegroups.com, kvm@vger.kernel.org, "Liam R. Howlett" , Linus Torvalds , linux-arm-kernel@axis.com, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-ide@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Lorenzo Stoakes , Marco Elver , Marek Szyprowski , Michal Hocko , Mike Rapoport , Muchun Song , netdev@vger.kernel.org, Oscar Salvador , Peter Xu , Robin Murphy , Suren Baghdasaryan , Tejun Heo , virtualization@lists.linux.dev, Vlastimil Babka , wireguard@lists.zx2c4.com, x86@kernel.org, Zi Yan Subject: Re: [PATCH RFC 07/35] mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages() Date: Fri, 22 Aug 2025 10:09:51 -0700 Message-Id: <20250822170951.53418-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250821200701.1329277-8-david@redhat.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: nco1yrbiy5xchqtp733th387yygtionm X-Rspam-User: X-Rspamd-Queue-Id: 702E64000B X-Rspamd-Server: rspam05 X-HE-Tag: 1755882594-236230 X-HE-Meta: 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 MAyw41gu ThXix6W9lPfXpttFNssYN52NNxfT+J3r6ycp91pBOZAH1CQCmp/+361U95tgGXeQkypXfSpEpVXkckDBaPGT9mH+DvveZ2r4JouHM1p8xwispKxa6tlcZZL7d+m6Firg0eOYMm9iYww6FfgaaPzG/aUd4W36K3hnubqNNBVpGNW/vpdlI40vwQkti1d65XRcAQKJW3waB/Oa/CBOoeohlZLeujxPyOQ9gJAnT310WIoqCeLt7UzMklab8W0B6++Vs/ObI6vLIvp4Oo/rKDZ3wqx4VjnACmmM6rMeZ0749H2lUgxDCaKnLiusUEG9iyyezyye3rUfEgMuVLaw= 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 Thu, 21 Aug 2025 22:06:33 +0200 David Hildenbrand wrote: > Let's reject unreasonable folio sizes early, where we can still fail. > We'll add sanity checks to prepare_compound_head/prepare_compound_page > next. > > Is there a way to configure a system such that unreasonable folio sizes > would be possible? It would already be rather questionable. > > If so, we'd probably want to bail out earlier, where we can avoid a > WARN and just report a proper error message that indicates where > something went wrong such that we messed up. > > Signed-off-by: David Hildenbrand Acked-by: SeongJae Park Thanks, SJ [...]