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=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=no 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 5A5DBC388F9 for ; Fri, 23 Oct 2020 17:48:50 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 2C50D2168B for ; Fri, 23 Oct 2020 17:48:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="h9H11cgb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C50D2168B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20257-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 3594 invoked by uid 550); 23 Oct 2020 17:48:42 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 3573 invoked from network); 23 Oct 2020 17:48:41 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=uHs6b4ooy0rgFnXBjoHTZU/MFzwidZAAr9PXWq9UsVk=; b=h9H11cgbsiLIfnCVNg9C63PczJj6klub3nyQOP7k17qHXCkM3+IiRWUf+K8onV/M6f cq6hpYWY5tijhMZOqe4vpxWnGOmq8cRM3qeYtsvRKEgPmJNNtDrmOS532+baO+0nsP5H 4oTZzToITDWX/+cRTyYkk0o02ppC4ZW2srP3cde+HPF1A0gWOS7McnJYg5AziS2A8+k5 FA/pfx2HXxsJo1PFtx/M/61rAc4BlJZES29IbLZRpqOuPDxsS+IoEvzMCqD9jME5DLTE nrFqzJCCPwXyQB8C7frIf3mqYooXH89m8/kypUCqoZ0QyzM52bhO/vCOCMQcptgtC5Xq D7GQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=uHs6b4ooy0rgFnXBjoHTZU/MFzwidZAAr9PXWq9UsVk=; b=TgxbPeRNo6aio2fojF8CtZ+AQewT2ylvR5pjRqpiivvHOZTIecF2szjiJI3RuHO4Y0 /MMu44jXUals2gHi3R4OQ/Ll3GUg/fWQ2EepDVSaMQRZlXJ8tAirr2pPAjNcrHdVh/ti xfLawokGpeLP/fw98KvVzMtsQld9aEpNqA4Ig3uSs1s1fR6x+0nWMt3YGPmFxtmBmNov bTJ0bzKT24nyNSluRqRXnBD4a/y6UFcwEYETtwX75bq1BMWkSUrE/Vjp8pMfDbZAlwnc 9l3VSSgROID6vauhCzHVB3xP7F1Nme+60fjrKmfLozKT/s0PBkWlPvygS83GO/SN/Rf8 Lz5g== X-Gm-Message-State: AOAM532uEujrC14qz62QTRb24zd8dmQF1kJmEUvaG+Bwp25MIjauHj81 rRddg3IAVISEFFjAEnKcGPkZWA== X-Google-Smtp-Source: ABdhPJyvkbZhNi51MOK3wMCs4cSy44OvLHixOCI7o3MOo/m8861HBGG5Vdka871MDYa0ozQesghZuQ== X-Received: by 2002:a17:90a:450d:: with SMTP id u13mr3848288pjg.148.1603475309279; Fri, 23 Oct 2020 10:48:29 -0700 (PDT) Date: Fri, 23 Oct 2020 10:48:22 -0700 From: Sami Tolvanen To: Peter Zijlstra Cc: Josh Poimboeuf , Jann Horn , the arch/x86 maintainers , Masahiro Yamada , Steven Rostedt , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux , Kernel Hardening , linux-arch , Linux ARM , linux-kbuild , kernel list , linux-pci@vger.kernel.org Subject: Re: [PATCH v6 22/25] x86/asm: annotate indirect jumps Message-ID: <20201023174822.GA2696347@google.com> References: <20201015102216.GB2611@hirez.programming.kicks-ass.net> <20201015203942.f3kwcohcwwa6lagd@treble> <20201020185217.ilg6w5l7ujau2246@treble> <20201021085606.GZ2628@hirez.programming.kicks-ass.net> <20201021093213.GV2651@hirez.programming.kicks-ass.net> <20201021212747.ofk74lugt4hhjdzg@treble> <20201022072553.GN2628@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201022072553.GN2628@hirez.programming.kicks-ass.net> On Thu, Oct 22, 2020 at 09:25:53AM +0200, Peter Zijlstra wrote: > On Wed, Oct 21, 2020 at 04:27:47PM -0500, Josh Poimboeuf wrote: > > On Wed, Oct 21, 2020 at 11:32:13AM +0200, Peter Zijlstra wrote: > > > On Wed, Oct 21, 2020 at 10:56:06AM +0200, Peter Zijlstra wrote: > > > > > > > I do not see these in particular, although I do see a lot of: > > > > > > > > "sibling call from callable instruction with modified stack frame" > > > > > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x10a: sibling call from callable instruction with modified stack frame > > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x99: (branch) > > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x3e: (branch) > > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x0: <=== (sym) > > > > > > $ nm defconfig-build/vmlinux.o | grep msr_write > > > 0000000000043250 t msr_write > > > 00000000004289c0 T msr_write > > > 0000000000003056 t msr_write.cold > > > > > > Below 'fixes' it. So this is also caused by duplicate symbols. > > > > There's a new linker flag for renaming duplicates: > > > > https://sourceware.org/bugzilla/show_bug.cgi?id=26391 > > > > But I guess that doesn't help us now. > > Well, depends a bit if clang can do it; we only need this for LTO builds > for now. LLD doesn't seem to support -z unique-symbol. Sami