From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F1184285C91; Fri, 22 Aug 2025 17:09:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755882594; cv=none; b=bsanKgWmNcKU+nLuyLpnQSLETDHjtxuZRyKIldH0b1QGd9Rt7obZHytBU7Isfh+BOr/jn/lhAjKrRp2QIz2vR9lRiluwMY3UJ7BLb2DjJMg77RPblTvKhAP9ay4ewDZNE+g2To+ewQZefJ/0HwzwdhneF8QorC4q6vYmSV5CgUA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755882594; c=relaxed/simple; bh=NEyazjWgDDK3Y8sTMLiPKtOTS94IEzEQJlr1MXdW648=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=blb+KATW03u+cDSLyCvIVamBMaBM3BO9IYu6uEPnelZvBc5e6XXqITWaxySX8U+Sg/H4UtVUGY9FtKz1tW+zveJXW2KZxEDSP/3VmtBEMDCxbyB7vv1X4NQCOqNluDz7DXDQQdzDbtweKzPx9cvxomvBQKtfN9sR8zBuA5HNZVk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DmWBU4Vz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DmWBU4Vz" 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: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 [...]