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 5D6472C11C5; Thu, 13 Nov 2025 09:06:49 +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=1763024809; cv=none; b=OUgp+Bm8DVP5TfGx34piFXbBw3hjYY9uI4EFa0YZvaIrzFHDX+qSz9mknRzdk2dVYJDQAAR1rrF/Sd7CFjRrc85shqoe59fpI2q3dHWVY7IvKhYCPPl4xOkI5zHHUHtPwzAS+2Phe7OMnjTH1TSpX7ahuGRl5rnRNp4WNvEhiTU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763024809; c=relaxed/simple; bh=kzjNmKxRv2HTgs2BLleVn+WPjcFHAp+Wpu1+B0RTMcg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AwGAeloTQHhSampuR9Nib+lldJFh082V3OG3qp/9z6upsKlFPRsUyEeStgGxb8gLIGsnmaheFfqZSSHtzaCOFh50n7ijm7rc8Mn+zm9zpdb8Mzc5Zk96PGaRoWyXFamdPkZe2vFvAYOF4dEcQQSIVekP9EHKwJ2+oih3CwSFfqk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rMMueHiG; 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="rMMueHiG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 871ABC16AAE; Thu, 13 Nov 2025 09:06:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763024808; bh=kzjNmKxRv2HTgs2BLleVn+WPjcFHAp+Wpu1+B0RTMcg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rMMueHiGvlrNs0GOCrftUTNWmns+IBBzry02OQpjdL86fQD1Vt2a34qjLTyOMa6oO q2CHwNgbCa4RZFauDEOSNlG6DdPb29aKc8eLeNgi88psiR5iehoQiw3AT5pafglAK0 lV8xWJNCMAzM4IFbXKq8i8lkO+PX4j0xY7uNPy2jrnFpSiV9/3SshWEfIR7tTWsB7H ioy3iuygOXPiNUqvH1KssnH/7XuxzmU/j1CH+6xt7Nk0uuVQHLjjP1BV1kD7hMbrBv MTlJDSM+sgcKd0ie3cIVt8OjXBQvoKl0cN7IQdtwUWx8bSlOAodKyl6EOH0A44NfOt T5l6xJqgvIwgg== Message-ID: Date: Thu, 13 Nov 2025 10:06:42 +0100 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: fix division-by-zero in uffd-unit-tests To: Carlos Llamas , Andrew Morton , Peter Xu , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Ujwal Kundur , Brendan Jackman Cc: kernel-team@android.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, "open list:MEMORY MANAGEMENT - USERFAULTFD" , "open list:KERNEL SELFTEST FRAMEWORK" References: <20251113034623.3127012-1-cmllamas@google.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251113034623.3127012-1-cmllamas@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 13.11.25 04:46, Carlos Llamas wrote: > Commit 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global > vars into struct") moved some of the operations previously implemented > in uffd_setup_environment() earlier in the main test loop. > > The calculation of nr_pages, which involves a division by page_size, now > occurs before checking that default_huge_page_size() returns a non-zero > This leads to a division-by-zero error on systems with !CONFIG_HUGETLB. > > Fix this by relocating the non-zero page_size check before the nr_pages > calculation, as it was originally implemented. > > Cc: stable@vger.kernel.org Do we CC stable on unit tests? From my recollection, no. > Fixes: 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global vars into struct") > Signed-off-by: Carlos Llamas > --- Acked-by: David Hildenbrand (Red Hat) -- Cheers David