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 X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03505C433DB for ; Fri, 5 Feb 2021 19:00:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 902E764E30 for ; Fri, 5 Feb 2021 19:00:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 902E764E30 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CF5B16B006C; Fri, 5 Feb 2021 14:00:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CA5DF6B006E; Fri, 5 Feb 2021 14:00:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B94AA6B0070; Fri, 5 Feb 2021 14:00:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id A2FAB6B006C for ; Fri, 5 Feb 2021 14:00:10 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 6370D181AEF1A for ; Fri, 5 Feb 2021 19:00:10 +0000 (UTC) X-FDA: 77785129380.25.door41_0d16c57275e7 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id 3AD871804E3A9 for ; Fri, 5 Feb 2021 19:00:10 +0000 (UTC) X-HE-Tag: door41_0d16c57275e7 X-Filterd-Recvd-Size: 4378 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Fri, 5 Feb 2021 19:00:09 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 75F1864DDD; Fri, 5 Feb 2021 19:00:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612551608; bh=bZuXQy1PiGC0sOhNm3CFAA7NXZxxgKQLuFfDc0NALKo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=t1ppFdNTYUUdVL9i1c3gehAV+Uj3jluSIWB7Nwe0zR4Cs2wAgMxnPEuJPgSF3f/Hk 42v1g+rj01vUAVTCncgfkcL+PJ0vCUQ9qb2K6qdU8QtF5xG3+lrzH2zFzC2UZeqiX+ MeXrQnKWWgnz9oDmA+rOfo1PU1tkKdUVkaXMvVNsJjjTIOWKvPG/JcdXfXZP932wQE YV3UBe65wWJ9g72kc6+0gLBEy5TyL1kUCuqL9uzUG7KzJaQEvp/zHogoDfsbCr2mH4 TfLDPnx1B8M/1iaoELpvwabLuhv0ev+fJHhf+srZPZ55SenLIIoKo1+8/0PEA2nboS Bo1GvzfVPaTvg== Date: Fri, 5 Feb 2021 12:00:05 -0700 From: Nathan Chancellor To: Kees Cook Cc: Arnd Bergmann , Andrew Morton , Nick Desaulniers , "Kirill A. Shutemov" , Wei Yang , Arnd Bergmann , Vlastimil Babka , Dmitry Safonov <0x7f454c46@gmail.com>, Brian Geffon , linux-mm@kvack.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH] mm/mremap: fix BUILD_BUG_ON() error in get_extent Message-ID: <20210205190005.GB461042@localhost> References: <20201230154104.522605-1-arnd@kernel.org> <20210112191634.GA1587546@ubuntu-m3-large-x86> <20210203184840.GA1711681@localhost> <202102031202.F0AEC4A7@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202102031202.F0AEC4A7@keescook> 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: On Wed, Feb 03, 2021 at 12:03:07PM -0800, Kees Cook wrote: > On Wed, Feb 03, 2021 at 11:48:40AM -0700, Nathan Chancellor wrote: > > On Tue, Jan 12, 2021 at 12:16:34PM -0700, Nathan Chancellor wrote: > > > On Wed, Dec 30, 2020 at 04:40:40PM +0100, Arnd Bergmann wrote: > > > > From: Arnd Bergmann > > > > > > > > clang cannt evaluate this function argument at compile time > > > > when the function is not inlined, which leads to a link > > > > time failure: > > > > > > > > ld.lld: error: undefined symbol: __compiletime_assert_414 > > > > >>> referenced by mremap.c > > > > >>> mremap.o:(get_extent) in archive mm/built-in.a > > > > > > > > Mark the function as __always_inline to avoid it. > > > > > > > > Fixes: 9ad9718bfa41 ("mm/mremap: calculate extent in one place") > > > > Signed-off-by: Arnd Bergmann > > > > > > I would like to see some movement on getting this fixed in 5.11. As it > > > stands, this is one of three __compiletime_assert references with > > > CONFIG_UBSAN_UNSIGNED_OVERFLOW. If we want to keep the BUILD_BUG() > > > around, I think this is fine. Alternatively, turning it into a runtime > > > check would be fine too. > > > > > > Reviewed-by: Nathan Chancellor > > > > Ping? It is pretty late into the 5.11 cycle and this is still broken. > > I think we should just do the __always_inline. Who can take this? This should probably go through -mm, unless we get an ack then Nick and I could take it. > > > > Cheers, > > Nathan > > > > > > --- > > > > mm/mremap.c | 5 +++-- > > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/mm/mremap.c b/mm/mremap.c > > > > index c5590afe7165..1cb464a07184 100644 > > > > --- a/mm/mremap.c > > > > +++ b/mm/mremap.c > > > > @@ -336,8 +336,9 @@ enum pgt_entry { > > > > * valid. Else returns a smaller extent bounded by the end of the source and > > > > * destination pgt_entry. > > > > */ > > > > -static unsigned long get_extent(enum pgt_entry entry, unsigned long old_addr, > > > > - unsigned long old_end, unsigned long new_addr) > > > > +static __always_inline unsigned long get_extent(enum pgt_entry entry, > > > > + unsigned long old_addr, unsigned long old_end, > > > > + unsigned long new_addr) > > > > { > > > > unsigned long next, extent, mask, size; > > > > > > > > -- > > > > 2.29.2 > > > > Cheers, Nathan