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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 AD8CAC54FD0 for ; Thu, 23 Apr 2020 07:50:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9740721775 for ; Thu, 23 Apr 2020 07:50:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbgDWHus (ORCPT ); Thu, 23 Apr 2020 03:50:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727051AbgDWHtu (ORCPT ); Thu, 23 Apr 2020 03:49:50 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BF7EC03C1AB; Thu, 23 Apr 2020 00:49:50 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jRWcB-0008OZ-Kj; Thu, 23 Apr 2020 09:49:43 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 46F861C047B; Thu, 23 Apr 2020 09:49:40 +0200 (CEST) Date: Thu, 23 Apr 2020 07:49:39 -0000 From: "tip-bot2 for Peter Zijlstra" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: objtool/core] x86,ftrace: Shrink ftrace_regs_caller() by one byte Cc: "Peter Zijlstra (Intel)" , Miroslav Benes , Alexandre Chartre , Josh Poimboeuf , Ingo Molnar , x86 , LKML In-Reply-To: <20200416115118.867411350@infradead.org> References: <20200416115118.867411350@infradead.org> MIME-Version: 1.0 Message-ID: <158762817989.28353.12633424393537109680.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the objtool/core branch of tip: Commit-ID: 9f2dfd61dd022d4559d42a832fb03e76aad36c5f Gitweb: https://git.kernel.org/tip/9f2dfd61dd022d4559d42a832fb03e76aad36c5f Author: Peter Zijlstra AuthorDate: Wed, 01 Apr 2020 16:51:11 +02:00 Committer: Ingo Molnar CommitterDate: Wed, 22 Apr 2020 10:53:50 +02:00 x86,ftrace: Shrink ftrace_regs_caller() by one byte 'Optimize' ftrace_regs_caller. Instead of comparing against an immediate, the more natural way to test for zero on x86 is: 'test %r,%r'. 48 83 f8 00 cmp $0x0,%rax 74 49 je 226 48 85 c0 test %rax,%rax 74 49 je 225 Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Miroslav Benes Reviewed-by: Alexandre Chartre Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20200416115118.867411350@infradead.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace_64.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index be9aff2..9738ed2 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -240,8 +240,8 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) * See arch_ftrace_set_direct_caller(). */ movq ORIG_RAX(%rsp), %rax - cmpq $0, %rax - je 1f + testq %rax, %rax + jz 1f /* Swap the flags with orig_rax */ movq MCOUNT_REG_SIZE(%rsp), %rdi