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 D404123741; Wed, 13 May 2026 00:43:00 +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=1778632980; cv=none; b=GXkAkJtYMpBomL+1pz2/Xon67EBZePb64lhuI5OiE5HGTGUyGPS35z8aAM6hprt1WQqW/HEc6yLS7yCa2F6PnYG9et+biyuEEsQhX/Z/DgYM2USjipWlmvkwbgwqcWzbWBpZBqIOV1/kEFpkR7SWT+7HjnG09wT2C3tlkhNCz8I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778632980; c=relaxed/simple; bh=F67x74zQHDavInVewpEn45XQx3OuQF+BwWkBzVhar/A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UQQPODgagLzToyL0RHveNtMyjWGJ2ti90awZMKi31qiql7Pvl2UiiunT5eTN3qp015dytX6KVzPZMvM/NGIx4YB6Lfx699+O+VUe0mBxZNwmGwhbUD6kslyUIob4QzFD2II88okFSICSKzv4qQXidWwlugbKZ76f0xv0GCRLna8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RJ2dmddO; 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="RJ2dmddO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E16C3C2BCB0; Wed, 13 May 2026 00:42:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778632980; bh=F67x74zQHDavInVewpEn45XQx3OuQF+BwWkBzVhar/A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; 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: Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 [...]