From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 12A47CCF9E3 for ; Mon, 10 Nov 2025 10:33:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 635D68E0007; Mon, 10 Nov 2025 05:33:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 60D1C8E0002; Mon, 10 Nov 2025 05:33:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5498B8E0007; Mon, 10 Nov 2025 05:33:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 433B78E0002 for ; Mon, 10 Nov 2025 05:33:23 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id E102BC0C0D for ; Mon, 10 Nov 2025 10:33:22 +0000 (UTC) X-FDA: 84094335444.06.1CF087B Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf28.hostedemail.com (Postfix) with ESMTP id 2E0B1C000D for ; Mon, 10 Nov 2025 10:33:20 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=J4JOMTZp; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf28.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762770801; a=rsa-sha256; cv=none; b=wxJFi0F4NyNDEGPMxpeRp3m2OAVPgSrc2YU0AAmjLcBc2LM/BVDqO4MZFbo7kIDsS42QQ6 k+ry3qvI6QzcIqDicl5Hjw6ZLcfTAhMEYVH82gHJhgVqP3s10QJKac/LrxyNRAV2n3vaxX Zmag+rY/29X8rzSkVNBuhfCEuicWA0g= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=J4JOMTZp; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf28.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762770801; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=uYngT3P0x8BeTeoq5JfLyRYHdqrmCoWdHOiiCCLVumA=; b=nOIiR7zNioVB5Rh+L1eHZmE4xKLT0InvyteWN7CBVhHKWLsz1y7gtqcmNUVg2lu35ZeUC3 IP3xwQ3TPTMeelzGGzxEYSCAs0TUhcVTDnrxJGJFhkutTODNJBnW8UEVG5K1wVy+/tly9f b970hjspAQ8/HsWYF+gAYgu0RaYJA6U= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id D19EC435D3; Mon, 10 Nov 2025 10:33:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70E38C4CEFB; Mon, 10 Nov 2025 10:33:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762770799; bh=XGdAZQMoYX6Us3MCpLM/NxmAUfTsARkCljiFE1chCCw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=J4JOMTZpT9f7JobhPkEEVtMbrvMHN/QmyRT6CkgFjCdJG5tsJTSz8geO6tHzfz4MZ GOtCv9QmePCfHi7gUxydKyaNAHExL86jJuMscDVKgAWHZ7EJQr57EVkxmdLu75Y+fa 0e1xo+JMgJNAA5omFi7cogT0zgMR1tsoDvsDgs7KZw1EhYLo4SQ8Go6krZUCmuxhX+ TlUwbp/UOOC/EQHwOjQ9q8LN4U6NTRoMDnhC0LYEYxbZTExqiiDH/Y7wbBEyqMfYlr r1v9Pp87oj1/1F+lROk+yyvElmJFs/KQ/dMSJPduQqa1ttaRNf6qVKNo4lb44QhkeA ibjK5TaviSRAQ== Date: Mon, 10 Nov 2025 12:33:11 +0200 From: Mike Rapoport To: Ankit Khushwaha Cc: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Shuah Khan , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] selftest/mm: fix pointer comparison in mremap_test Message-ID: References: <20251108161829.25105-1-ankitkhushwaha.linux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251108161829.25105-1-ankitkhushwaha.linux@gmail.com> X-Rspamd-Queue-Id: 2E0B1C000D X-Rspamd-Server: rspam07 X-Stat-Signature: nx36hp5rizfctc1r9mb973u556xiqcy1 X-Rspam-User: X-HE-Tag: 1762770800-400646 X-HE-Meta: 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 oLjUWXIQ /5NLm8Sy/C4fC6cM7NxKdHNClx67c3K0JRhrIn+JxkZKzMcNS11ygtbp5axH+r49qScRw1rEDpUpMfP+BslZR1ywz/Frp15ds5rX8pI3ZwJK5lF+Pvjt2D+W3su4tIPFFecU21h/1x4MOWdo1CG6baXkmFdBQgW2jfj8u9Eao/0czAT5l8EfH5W0R2CoHGT1LOMCatjdvBS3TOV4EsIWgJ+9Lzg4Ku4yHMHWcz9hIbc2ya7CSAlAD28IBUO1wjQKRyomp4CrqpG3HgjVeZYRTLWe5i8Ij4LJOv2QgYu2V+ZDFEE7GrqF2aIBlHttIwOqUjFGfdqu++fp9ntQ0PL9HEg3/omo1dw7S8XKbHJ5PjKq1v1C8Duer2l5o2MjEF9whepTGYW++k4Hoem/6fSl34R30VoRaSK0IRWTd3pJQ0EDcPpA= 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 Sat, Nov 08, 2025 at 09:48:29PM +0530, Ankit Khushwaha wrote: > Pointer arthemitic with 'void * addr' and 'ulong 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) { > | ^ > > this warning is raised from clang version 20.1.8 (Fedora 20.1.8-4.fc42). > > use 'void *tmp_addr' to do the pointer arthemitic. > > Signed-off-by: Ankit Khushwaha > --- > Changelog: > v2: > - use 'void *tmp_addr' for pointer arthemitic instead of typecasting > 'addr' to 'unsigned long long' as suggested by Andrew. > > v1: https://lore.kernel.org/linux-kselftest/20251106104917.39890-1-ankitkhushwaha.linux@gmail.com/ > --- > tools/testing/selftests/mm/mremap_test.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c > index a95c0663a011..308576437228 100644 > --- a/tools/testing/selftests/mm/mremap_test.c > +++ b/tools/testing/selftests/mm/mremap_test.c > @@ -994,7 +994,7 @@ static void mremap_move_multi_invalid_vmas(FILE *maps_fp, unsigned long page_siz > static long long remap_region(struct config c, unsigned int threshold_mb, > char *rand_addr) > { > - void *addr, *src_addr, *dest_addr, *dest_preamble_addr = NULL; > + void *addr, *tmp_addr, *src_addr, *dest_addr, *dest_preamble_addr = NULL; > unsigned long long t, d; > struct timespec t_start = {0, 0}, t_end = {0, 0}; > long long start_ns, end_ns, align_mask, ret, offset; > @@ -1032,7 +1032,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, > /* Don't destroy existing mappings unless expected to overlap */ > while (!is_remap_region_valid(addr, c.region_size) && !c.overlapping) { > /* Check for unsigned overflow */ > - if (addr + c.dest_alignment < addr) { > + tmp_addr = addr + c.dest_alignment; Nit: tmp_addr can be declared here. Other than that Acked-by: Mike Rapoport (Microsoft) > + if (tmp_addr < addr) { > ksft_print_msg("Couldn't find a valid region to remap to\n"); > ret = -1; > goto clean_up_src; > -- > 2.51.1 > -- Sincerely yours, Mike.