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b=SUCMD5rCWj/oJLM3Ldv8h7XQMawBx92SJwIAPYTByVK2UJEpkBnkk3NSlYWo7z2mK 5EciqmWn1brjUmACgkQUojIOAvnG0c8isq24sN7BXmL+KxyrfEw4wsfd1ldjXPWM9y eQ0eRniOpEft0u7RUfWjGy1rEeaipAvzqeEW/0sE= Date: Wed, 17 Jul 2024 20:46:16 -0700 From: Andrew Morton To: Jiapeng Chong Cc: shuah@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Abaci Robot Subject: Re: [PATCH -next] selftests/mm: mseal, self_elf: Fix warning comparing pointer to 0 Message-Id: <20240717204616.7a3d2465272d4f8fd1736831@linux-foundation.org> In-Reply-To: <20240718031039.69861-1-jiapeng.chong@linux.alibaba.com> References: <20240718031039.69861-1-jiapeng.chong@linux.alibaba.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 76AE11C0006 X-Stat-Signature: x3p43kounnxzmyk1mdfks864msg3k87h X-Rspam-User: X-HE-Tag: 1721274381-308650 X-HE-Meta: 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 c/AQ+017 yZz60bb56zhJ0/Z8P9H29pPk3fHShCZYWFu6mmaLhbwzz9O1Qn1Jwa20mr8uTqnkwTzrz4R3JxodwXv3//dBM5bhsfWvAhfi6U48NKsqo4VRtEE425pbhHO+Ndt1NaKKSRhOeXsPDZpe4Ccf52y/ttwWtJGcLKwMotCRtpznITAXFhxShcUcn3Mw295WAwMAvWSFAKjWIefXl+lesrvKObhiZJpHSp1LvctcT/WpZGAr+X846A2QmM0aHXpEAeVsedaZMs2dkT/Bs9Qe2mGyMtYeyo4BHd9+qyDMu 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, 18 Jul 2024 11:10:39 +0800 Jiapeng Chong wrote: > Avoid pointer type value compared with 0 to make code clear. > > ./tools/testing/selftests/mm/mseal_test.c:486:27-28: WARNING comparing pointer to 0. > ./tools/testing/selftests/mm/mseal_test.c:1399:29-30: WARNING comparing pointer to 0. > > ... > > --- a/tools/testing/selftests/mm/mseal_test.c > +++ b/tools/testing/selftests/mm/mseal_test.c > @@ -481,9 +481,8 @@ static void test_seal_zero_address(void) > int prot; > > /* use mmap to change protection. */ > - ptr = sys_mmap(0, size, PROT_NONE, > - MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); > - FAIL_TEST_IF_FALSE(ptr == 0); > + ptr = sys_mmap(0, size, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); > + FAIL_TEST_IF_FALSE(!ptr); > @@ -1390,13 +1389,12 @@ static void test_seal_mremap_move_fixed_zero(bool seal) > /* > * MREMAP_FIXED can move the mapping to zero address > */ > - ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED, > - 0); > + ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED, 0); The author of this code chose to make it tractable in an 80-column display. It's best not to change that, without explanation.