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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9ED00C433EF for ; Sat, 19 Feb 2022 05:22:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232729AbiBSFWn (ORCPT ); Sat, 19 Feb 2022 00:22:43 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:48566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231442AbiBSFWl (ORCPT ); Sat, 19 Feb 2022 00:22:41 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D658D3DA57 for ; Fri, 18 Feb 2022 21:22:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645248142; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=P9r+Bhfs5dDddqduzGiZYaJG4staNq0SxYzZYyrkYbI=; b=MTNLUZk2K2LteSWUtU1WLlQZ5MsvjQ+9XWCBLFB/dacKbbw5PsdcTrW4RhqpUnOyDC01qj +mG0I19X3kJnCV9V3WibWgi3/nCe7FPlXDaelxvRFL0G2pqYJVZPfnKXQy5fPz9NuyTik2 rE5iQQ98PsN0fX9QOxNl6XKOPXhtdTo= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-177-qj0T0RAKPrKo9YQHNE6J4A-1; Sat, 19 Feb 2022 00:22:21 -0500 X-MC-Unique: qj0T0RAKPrKo9YQHNE6J4A-1 Received: by mail-qv1-f71.google.com with SMTP id e9-20020a0cf749000000b0042bf697ff6bso11060837qvo.5 for ; Fri, 18 Feb 2022 21:22:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=P9r+Bhfs5dDddqduzGiZYaJG4staNq0SxYzZYyrkYbI=; b=d/eg+DQvaqB4sIP2lZdX/fmo/JSl4Q0KKLa68R5O/gNFojs9BCS8pfRiGZIVQGFjlG eOGsfMGvjRiLfrqyAefzBxgXtIX6Mz+BRKTtr10eCvUI06cILK5QVjpBBxkwQIHJFEkN MkmP7J7ukVvVozroB1AOcMgtqmSyCxHKc7YULv+USPDFCJGWpzR8olnjPDDmshdKClc+ OIh/Q+kmBD0O1BI3e7uIOeaQqW6c51pfh+Bcs47V3x/hQBYETmXq3aJmSZqaPjUC4CBu 4FdSEFQ6XX+FGT5iT0Kq8z/4mVd0kt5YNd7Z+ueFxCjZnt77rOSudHvpxhtGrk4S83xX FG+w== X-Gm-Message-State: AOAM533yf6o6qyb2CMJaE0yx3Ereq+chZhjwdWNFGjFiMZbeuM6tVcqO 67CYlEKsItIOw10lz7v6YuScty4DKt2nsfS5Vq9QcmVknBPKPgeHsg4qgBD69sj2uBl+kEWslMC kV1ThZ/5zyTJUb9rvH2GqJ1Ak X-Received: by 2002:a05:622a:13c6:b0:2d6:75cf:cc23 with SMTP id p6-20020a05622a13c600b002d675cfcc23mr9595842qtk.473.1645248140805; Fri, 18 Feb 2022 21:22:20 -0800 (PST) X-Google-Smtp-Source: ABdhPJxHO9z5PxXHTDIIDy7QdEheDxE0SOBADu6a7I5ZgJcPDSSKo8J1gtoH6AnueqXtBdR+w0nTjA== X-Received: by 2002:a05:622a:13c6:b0:2d6:75cf:cc23 with SMTP id p6-20020a05622a13c600b002d675cfcc23mr9595837qtk.473.1645248140580; Fri, 18 Feb 2022 21:22:20 -0800 (PST) Received: from treble ([2600:1700:6e32:6c00::35]) by smtp.gmail.com with ESMTPSA id e3sm3473029qto.25.2022.02.18.21.22.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Feb 2022 21:22:20 -0800 (PST) Date: Fri, 18 Feb 2022 21:22:16 -0800 From: Josh Poimboeuf To: Peter Zijlstra Cc: x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com, andrew.cooper3@citrix.com, linux-kernel@vger.kernel.org, ndesaulniers@google.com, keescook@chromium.org, samitolvanen@google.com, mark.rutland@arm.com, alyssa.milburn@intel.com Subject: Re: [PATCH 17/29] x86/ibt: Annotate text references Message-ID: <20220219052216.7b5fx6qileqrdjbw@treble> References: <20220218164902.008644515@infradead.org> <20220218171409.579455015@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220218171409.579455015@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 18, 2022 at 05:49:19PM +0100, Peter Zijlstra wrote: > Annotate away some of the generic code references. This is things > where we take the address of a symbol for exception handling or return > addresses (eg. context switch). > > Signed-off-by: Peter Zijlstra (Intel) The vast majority of these annotations can go away if objtool only requires ENDBR for referenced *STT_FUNC* symbols. Anything still needing ANNOTATE_NOENDBR after that, might arguably not belong as STT_FUNC anyway and it might make sense to convert it to non-function code (e.g. SYM_CODE{START,END}. > @@ -564,12 +565,16 @@ SYM_CODE_END(\asmsym) > .align 16 > .globl __irqentry_text_start > __irqentry_text_start: > + ANNOTATE_NOENDBR // unwinders > + ud2; > > #include > > .align 16 > .globl __irqentry_text_end > __irqentry_text_end: > + ANNOTATE_NOENDBR > + ud2; Why ud2? If no ud2 then the annotation shouldn't be needed since the first idt entry has ENDBR. -- Josh