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=-17.5 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,USER_AGENT_SANE_1 autolearn=unavailable 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 83BCCC433E0 for ; Tue, 16 Feb 2021 18:56:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A73764E42 for ; Tue, 16 Feb 2021 18:56:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231205AbhBPSzt (ORCPT ); Tue, 16 Feb 2021 13:55:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:48208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231135AbhBPSza (ORCPT ); Tue, 16 Feb 2021 13:55:30 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 60A9264EC8; Tue, 16 Feb 2021 18:54:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613501690; bh=XLdhnbxpQyUDI0ibwdZi9VWVTk4/FfIbiYNNHh0bGMo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PRPLQ5TwQ5HAvg963yD0IXfVeTU1PfgILSKT/zALIcuO2gE1ArT2oqoNRTFx0AvkL Re4t0dwNDMixZhUOBCnYlnUB4SUeeYbZA69yoB4O7I10DK7/mYSn+QaVeqptrom6ur fnCSuUvoYuIeNRqm1b7cMjhQbmEWOKDYRmGAXaE2A6YAKDixOHVxou7r7qbM8dQM+a XsHab8VVEigD8OhpAPfQ3dvi5fjwDwetEAjQjpOYTtLPusx8Jcw3h+lEbT14SByHeb L/rNkZjdiHrSlh0prLOEYNxbHJBSbQp2ArM+CHdx7e0ov4UxiHmUmTwsxK4TtiuCOZ sAORhJdGrR50Q== Date: Tue, 16 Feb 2021 11:54:47 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Alexander Lobakin , Thomas Bogendoerfer , Arnd Bergmann , Nathan Chancellor , Huacai Chen , Pei Huang , Kees Cook , Sami Tolvanen , Fangrui Song , Jiaxun Yang , Ralf Baechle , Corey Minyard , kernel test robot , linux-mips@vger.kernel.org, LKML , linux-arch , clang-built-linux Subject: Re: [PATCH mips-next] vmlinux.lds.h: catch more UBSAN symbols into .data Message-ID: <20210216185447.GA64303@24bbad8f3778> References: <20210216085442.2967-1-alobakin@pm.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 16, 2021 at 09:56:32AM -0800, 'Nick Desaulniers' via Clang Built Linux wrote: > On Tue, Feb 16, 2021 at 12:55 AM Alexander Lobakin wrote: > > > > LKP triggered lots of LD orphan warnings [0]: > > Thanks for the patch, just some questions. > > With which linker? Was there a particular config from the bot's > report that triggered this? Looks like GNU ld 2.34 (see below). > > > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data299' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data299' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data183' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data183' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type3' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type3' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type2' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type2' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type0' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type0' > > > > [...] > > > > Seems like "unnamed data" isn't the only type of symbols that UBSAN > > instrumentation can emit. > > Catch these into .data with the wildcard as well. > > > > [0] https://lore.kernel.org/linux-mm/202102160741.k57GCNSR-lkp@intel.com > > > > Fixes: f41b233de0ae ("vmlinux.lds.h: catch UBSAN's "unnamed data" into data") > > Reported-by: kernel test robot > > Signed-off-by: Alexander Lobakin > > --- > > include/asm-generic/vmlinux.lds.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > > index cc659e77fcb0..83537e5ee78f 100644 > > --- a/include/asm-generic/vmlinux.lds.h > > +++ b/include/asm-generic/vmlinux.lds.h > > @@ -95,7 +95,7 @@ > > */ > > #ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION > > #define TEXT_MAIN .text .text.[0-9a-zA-Z_]* > > -#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* > > +#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$Lubsan_* > > Are these sections only created when > CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is selected? (Same with > .data.$__unnamed_*) Most likely, as that config is set in the problematic config. My guess is that these are GCC's equivalent of Clang's .data.$__unnamed_... $ crl https://lore.kernel.org/linux-mm/202102160741.k57GCNSR-lkp@intel.com/2-a.bin | gzip -d | rg "CONFIG_LD_DEAD_CODE|CONFIG_LD_VERSION" CONFIG_LD_VERSION=234000000 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y > > #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]* > > #define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L* > > #define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral* > > -- > > 2.30.1 > > > > > > > -- > Thanks, > ~Nick Desaulniers >