From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751805AbdG1HmC (ORCPT ); Fri, 28 Jul 2017 03:42:02 -0400 Received: from terminus.zytor.com ([65.50.211.136]:35353 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751610AbdG1Hl7 (ORCPT ); Fri, 28 Jul 2017 03:41:59 -0400 Date: Fri, 28 Jul 2017 00:37:31 -0700 From: tip-bot for Josh Poimboeuf Message-ID: Cc: arnd@arndb.de, linux-kernel@vger.kernel.org, jpoimboe@redhat.com, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org Reply-To: hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, peterz@infradead.org, torvalds@linux-foundation.org, arnd@arndb.de, linux-kernel@vger.kernel.org, jpoimboe@redhat.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] objtool: Skip unreachable warnings for 'alt' instructions Git-Commit-ID: 0e2bb2bc14b3df754b0a86e87cd8923df0701a1b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 0e2bb2bc14b3df754b0a86e87cd8923df0701a1b Gitweb: http://git.kernel.org/tip/0e2bb2bc14b3df754b0a86e87cd8923df0701a1b Author: Josh Poimboeuf AuthorDate: Thu, 27 Jul 2017 15:56:54 -0500 Committer: Ingo Molnar CommitDate: Fri, 28 Jul 2017 08:33:32 +0200 objtool: Skip unreachable warnings for 'alt' instructions When a whitelisted function uses one of the ALTERNATIVE macros, it produces false positive warnings like: arch/x86/kvm/vmx.o: warning: objtool: .altinstr_replacement+0x0: unreachable instruction arch/x86/kvm/svm.o: warning: objtool: .altinstr_replacement+0x6e: unreachable instruction There's no easy way to whitelist alternative instructions, so instead just skip any 'unreachable' warnings associated with them. Reported-by: Arnd Bergmann Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/a5d0a8c60155f03b36a31fac871e12cf75f35fd0.1501188854.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- tools/objtool/check.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index d07bf4a..4f0c4ae 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1746,8 +1746,13 @@ static bool ignore_unreachable_insn(struct instruction *insn) /* * Ignore any unused exceptions. This can happen when a whitelisted * function has an exception table entry. + * + * Also ignore alternative replacement instructions. This can happen + * when a whitelisted function uses one of the ALTERNATIVE macros. */ - if (!strcmp(insn->sec->name, ".fixup")) + if (!strcmp(insn->sec->name, ".fixup") || + !strcmp(insn->sec->name, ".altinstr_replacement") || + !strcmp(insn->sec->name, ".altinstr_aux")) return true; /*