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[34.118.241.116]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2985c245f8asm28347325ad.37.2025.11.13.07.01.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Nov 2025 07:01:30 -0800 (PST) Date: Thu, 13 Nov 2025 15:01:25 +0000 From: Carlos Llamas To: Lorenzo Stoakes Cc: "David Hildenbrand (Red Hat)" , Andrew Morton , Peter Xu , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Ujwal Kundur , Brendan Jackman , kernel-team@android.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, "open list:MEMORY MANAGEMENT - USERFAULTFD" , "open list:KERNEL SELFTEST FRAMEWORK" Subject: Re: [PATCH] selftests/mm: fix division-by-zero in uffd-unit-tests Message-ID: References: <20251113034623.3127012-1-cmllamas@google.com> <4a60a703-d9c2-46a8-83b4-a7ecff7f6ba2@lucifer.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4a60a703-d9c2-46a8-83b4-a7ecff7f6ba2@lucifer.local> X-Rspamd-Queue-Id: 4AA4010001A X-Rspamd-Server: rspam07 X-Stat-Signature: p6eqfxmws74go3bx1z3ioucggrykxp7i X-Rspam-User: X-HE-Tag: 1763046093-251210 X-HE-Meta: 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 RSkLzY1Q 4oRf5axEK8TQmJZzpbycZ6FS9o+Z4Rzz/BpXr60ZDu5W0Yu3HSw8sjIyWpyE2k6YJqZj3OQl/9a4SAKCdLXGQvkZy3O3K74Xjnyn7xuYyuuUbVSLv5NX+yUp9QzOpuoNRMP2up+GVYg9mspGBmDhbn6yqX5OGLiJAcg0b/Vck6bCkQcLBv9igXVtesm6k52BRceIe+uvXGMhG6bZATDkqaXhW/ttQdS5aPpf78iwZXQUHQhMwq40cxv/LVXg44LHRinTBQ0b4RtzIr7amhU4sEWJ1bWm7zWstPvx63gvaIBs78IxkC5lq07W8efb5WTpGT9xB8Mn+XOHMunpKyB6T+EFC18BAenTG86VVVbfPkYzT98FPCoJsf6ybiUGcBfeIXKb34jrZlZ/qVYQ2ERW8ReIqsJ0if1k+roM4E8phLfAKMQJJusaZNMKfFarbEZRJ/3gyu3lZwm60PIo= 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, Nov 13, 2025 at 09:54:37AM +0000, Lorenzo Stoakes wrote: > On Thu, Nov 13, 2025 at 10:06:42AM +0100, David Hildenbrand (Red Hat) wrote: > > 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. > > Yeah please let's not. Oops, I keep getting confused about this Cc stable thing. Please let me know if a v2 dropping the tag is needed. -- Carlos Llamas