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 0DA81C4332F for ; Mon, 17 Oct 2022 14:56:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231383AbiJQO4L (ORCPT ); Mon, 17 Oct 2022 10:56:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231169AbiJQOyP (ORCPT ); Mon, 17 Oct 2022 10:54:15 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93D2F69183; Mon, 17 Oct 2022 07:54:01 -0700 (PDT) Date: Mon, 17 Oct 2022 14:53:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1666018438; h=from:from:sender:sender:reply-to: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n4Ok/fbnGAmjEVN0Qr/zdNfOqF8J2v/Ks5qkqOG/fFc=; b=yVJTgeMUxjMngVvb5cLb/vARREnRTPx6OfvRt7NMqoAA7dR//AE7tLi8iQx/qPLr2Kml5e Qbz68jzRhZbKlny1d+X+PlPo2BtTPtPOX9MlnvW4kZjKUiv78Kj5XEQCR5xc1lX1DZ1nRN wzIzCzzCCWWlJk5wWtZ3SxzDuSlU9oWBIXGhqH5t1vuZsfabILcIccL1aOBjzj+i+ifB2N tOUSYBK8pp/i2S0j7RGv9IpAJKcL4KU9B+uLiKvyYgp02GhOJ2yFc1VColL42NYBIsAf/J oIANLUe09cCFeS4N7+MYb5VUFE3ZmL0LTN16LKfMQX0tpJoCgmlYcPDuBZWrJg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1666018438; h=from:from:sender:sender:reply-to: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n4Ok/fbnGAmjEVN0Qr/zdNfOqF8J2v/Ks5qkqOG/fFc=; b=Q9FZRN/CyyJW86hEx72s2W78KVpFK61a5YeQ7Bcp0zSN84DLzpXQYH4a+ur1xT3IMd9RS4 23ujCG8mPy17LwBQ== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/core] objtool: Allow symbol range comparisons for IBT/ENDBR Cc: "Peter Zijlstra (Intel)" , Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220915111146.434642471@infradead.org> References: <20220915111146.434642471@infradead.org> MIME-Version: 1.0 Message-ID: <166601843692.401.16934924351803630402.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/core branch of tip: Commit-ID: 08ef8c40112b8cd157515cd532f65cb82c934a76 Gitweb: https://git.kernel.org/tip/08ef8c40112b8cd157515cd532f65cb82c934a76 Author: Peter Zijlstra AuthorDate: Thu, 15 Sep 2022 13:11:13 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 17 Oct 2022 16:41:08 +02:00 objtool: Allow symbol range comparisons for IBT/ENDBR A semi common pattern is where code checks if a code address is within a specific range. All text addresses require either ENDBR or ANNOTATE_ENDBR, however the ANNOTATE_NOENDBR past the range is unnatural. Instead, suppress this warning when this is exactly at the end of a symbol that itself starts with either ENDBR/ANNOTATE_ENDBR. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220915111146.434642471@infradead.org --- arch/x86/entry/entry_64_compat.S | 1 - tools/objtool/check.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 1dfee86..bc45ea7 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -128,7 +128,6 @@ SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL) popfq jmp .Lsysenter_flags_fixed SYM_INNER_LABEL(__end_entry_SYSENTER_compat, SYM_L_GLOBAL) - ANNOTATE_NOENDBR // is_sysenter_singlestep SYM_CODE_END(entry_SYSENTER_compat) /* diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 1461c88..3f46f46 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4033,6 +4033,24 @@ static void mark_endbr_used(struct instruction *insn) list_del_init(&insn->call_node); } +static bool noendbr_range(struct objtool_file *file, struct instruction *insn) +{ + struct symbol *sym = find_symbol_containing(insn->sec, insn->offset-1); + struct instruction *first; + + if (!sym) + return false; + + first = find_insn(file, sym->sec, sym->offset); + if (!first) + return false; + + if (first->type != INSN_ENDBR && !first->noendbr) + return false; + + return insn->offset == sym->offset + sym->len; +} + static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn) { struct instruction *dest; @@ -4105,9 +4123,19 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn continue; } + /* + * Accept anything ANNOTATE_NOENDBR. + */ if (dest->noendbr) continue; + /* + * Accept if this is the instruction after a symbol + * that is (no)endbr -- typical code-range usage. + */ + if (noendbr_range(file, dest)) + continue; + WARN_FUNC("relocation to !ENDBR: %s", insn->sec, insn->offset, offstr(dest->sec, dest->offset));