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 DE5212E229C; Fri, 7 Nov 2025 09:27:32 +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=1762507653; cv=none; b=El7BCk0X7/1b4HA28pYKrsoJnwUgU+6Mk1pbDc4dcFlLI8f6z0zDJhdZFltPs8JmEoc3Oqo9OnXKKM+Un40ouFKHyQundaS/6lymLAUCiWwOk3uUu+lDkZAwTI4gf/EchdZiEldQWj2FYoRRs6A5A955VmSgDyPgfwFDItAvNo8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762507653; c=relaxed/simple; bh=XYsZOHDCQvqBnfIJG8n72IsqXz8wRu5FCAMH1Fh68L8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=R5gk0MNoTd23tQpWeDJaQojZ/LDL0yt+PmkZT28jyJG+XdVJsMdAg+gwUbyzY+ezVzGzGGRE11IJRFS6M8X17r1ZXInYppjHjFUALcxzPOqUhcCQ7sAyhlyZnizTKt4AptHSGWrZzgHXjhThSvaLWCkrpofX1naeP8n0jAOTS2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=L+KqY78U; 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="L+KqY78U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65B39C19423; Fri, 7 Nov 2025 09:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762507652; bh=XYsZOHDCQvqBnfIJG8n72IsqXz8wRu5FCAMH1Fh68L8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=L+KqY78U5Aw8o2oFDAC9jsuAfpaoekJrMt9UmrwJZZ0IuMSJpB5oih+tmojGWpYmF CSW4agR0Ki5dfjyQqPpDDNMck6Po/SHEklb3UdtbBVN/tlwVIJutMAvTQk+T9sJ8Bk 5DmZXrEgpsQDNnlglx7teswqt1Lrh6fNpjMuRgfR2xrezYr4BnWuaJAiQXwWXvPAwz 0bdfriP8Lv8haXp3SVfdAw5w22/5H6c3cxo26kCeLzRYopHrypfnK9mE7QBYyPgX+j I1wCfHzqQtDOcp+OFq09FHUFlOTk5+Kv5O/fuOryyYSxAdLqfqID3B45ME/ih4CU5z bfcESEkKYBDQQ== Message-ID: <6e07949b-d86f-46d8-a68c-9717cfb26084@kernel.org> Date: Fri, 7 Nov 2025 10:27:27 +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] selftest/mm: fix pointer comparison in mremap_test To: Ankit Khushwaha Cc: Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20251106104917.39890-1-ankitkhushwaha.linux@gmail.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 06.11.25 13:02, Ankit Khushwaha wrote: > On Thu, Nov 06, 2025 at 12:18:57PM +0100, David Hildenbrand (Red Hat) wrote: >> On 06.11.25 11:49, Ankit Khushwaha wrote: >>> Pointer arthemitic with 'void * addr' and 'unsigned long long dest_alignment' >>> triggers following warning: >>> >>> mremap_test.c:1035:31: warning: pointer comparison always evaluates to >>> false [-Wtautological-compare] >>> 1035 | if (addr + c.dest_alignment < addr) { >>> | ^ >>> >>> typecasting 'addr' to 'unsigned long long' to fix pointer comparison. >> >> With which compiler are you seeing this? > > Hi David, > > clang version 20.1.8 (Fedora 20.1.8-4.fc42) raised this warning. > > To reproduce: > make -C tools/testing/selftests/mm CC=clang Thanks, and thanks to Lorenzo for the details. Acked-by: David Hildenbrand (Red Hat) -- Cheers David