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b=RJ2dmddOQdMDLftsFFJcND6nRRMR1+HtKsSZc3SxDbKf+/cdldMq5ap3SZ6pb75wt lB5WpDIQEkLKX051okiB5uFRqVHDFM/PUHvfTaB4yHyEHRwB7aGJBcEQ/eukiHbLUg oEgZ5+/f+DPlYQvY21MRaHtpmYYZ6SRn0sjX4EPBX+BjhpuqX/0cOJo3Z55JS6sgJW FdzUp+QBd6gmb4CtSlIjs+A+y3l193N3X6rghhph4qS7Y2asFhU2iFNqpTZ3aKFPnR fyDwNHb38Q+SmLVW68BiZS0Pjmst6yFnnOzKyKzwYGVtyl7BA4bc7Q/vCvs2ZIzYP3 wos4kr2I5IilQ== From: SeongJae Park To: Hongfu Li Cc: SeongJae Park , jgg@ziepe.ca, leon@kernel.org, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] selftests/mm: Fix mmap() return value check in run_migration_benchmark Date: Tue, 12 May 2026 17:42:51 -0700 Message-ID: <20260513004252.118855-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260512101305.139509-1-lihongfu@kylinos.cn> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 9F3AD4000B X-Rspam-User: X-Stat-Signature: xtkpj8eeofqr8xzco3yty1opb94uneeh X-HE-Tag: 1778632981-5753 X-HE-Meta: U2FsdGVkX1+waz7VSo4MpJuc3N0sXrN0HDOUcZc7No93/WLckTR0l87wlcQLspbT2VpyhW/Xtn4jo8Kh3CE4l4kO8CVGUgp4dOQOpckZS2okhI/mN7Lwr04OtBVQ5lmBkjs8RGYU+PSv+7u1ZozkwEdFudxPSnIZBxho1AyHc3tB39w7O2dWegHgx/HByjMoxQbKNfInXWjqaghxRP+LBxbZ3S8PhkQGGdeJcTnX7uvL03/1oULrOj/MMibDjzR2uf0q+CRoLe97oQNgoJ7sURePmTQ9L/8pyPNJlBzIIjxc5kZAYbKRpkhL2mf4Owa5issMUaJhj0sKSpRhrUqhFIqtF9aDqLnOTzQ0hNz5tin8xfW5kltS+HRSbnv5dtfNbcO6M73ldQa+aDwtKe1NxRv3Pkp1QPhkzB1fRZQyxTlOoBdypaTiPd42szcx1jXOu740hCiRXq1m38cxQyGAxInJS5ntLsVPgk+PBwBxY+aZn+MQiYue3daEHpugklZtLBYRfMCm7UeFyySSzaqCKslL+LBDrG+G5d1E+mEQd7W1BOCTG4aDqWFDuGGgWUREz+xTBoOEIgnbP2mFucUwBQ+54h3PCc02XP4Ppwby6jWQdBwp0yEzQbc8IqVHXOW5X8QDgWGvGq8RDXkrnM8RgFIwH1+3Y/4YQjs9Z4M3os6lIgHYlXjHX2of5WX7bxOyuuxIYe8H6slhusga/3pT/HbTm9gY3dNsxABDLIg7OsBBR2+23GFUULXZn/rApYPiKJUUfpodT6RjHWfYFxgFc7uNlpt5YOwC7JZSAB1tPfUNlAotxv8xLeJqQIJKDknKDtB/aoYV2iOOlDjZQpM6jlG5Njr/UTO/7BubuX7eHlFj/O3kRYgFPnfz8mwVOLU6RjjY2QOWPzrqVPljwHBc+Xhj6hrROsVfA5edz76pw2TjFNdtCLQeQrD3Jz5uWXhm0I9n8pEAZmYKBqqcBee +IBpfjhF 8VHuH29n9fdZMc+qjZrtE/z9LO3ix3wSiBz+iw81mnOi0Fhh2Ywz6LK0SD//8y1NFxM7nenwUTmAM0ai6fZnFUAP/3iZVIfCrU3FIHD3yIcEMv5tUKcq8/DG2hEDGwIeX2R+m64bCk1LdQc+HppNm02Fgtgnh2oGgijPPzX87IWM15Hbxcutvc4wvlkUupuQ6xeM9qkKEz6sBRahb1xCvNdkZ5pmey64j0IXrd9KM8CSFEhj//uxFSqqNwV2icOz26HWfNW/1Yy3NZxWovsy0dTIhHg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 12 May 2026 18:13:05 +0800 Hongfu Li wrote: > mmap() returns MAP_FAILED on error, not NULL. The current check uses > !buffer->ptr, which evaluates to false when mmap() fails (since > MAP_FAILED is (void *)-1, not 0), so the error path is never taken. Good catch, thank you! > > Signed-off-by: Hongfu Li Reviewed-by: SeongJae Park Thanks, SJ [...]