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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AC2E4C433C1 for ; Wed, 24 Mar 2021 17:37:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D1AA61A19 for ; Wed, 24 Mar 2021 17:37:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237470AbhCXRhR (ORCPT ); Wed, 24 Mar 2021 13:37:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237456AbhCXRgt (ORCPT ); Wed, 24 Mar 2021 13:36:49 -0400 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62FFEC061763; Wed, 24 Mar 2021 10:36:49 -0700 (PDT) Received: by mail-ej1-x62c.google.com with SMTP id ce10so34259660ejb.6; Wed, 24 Mar 2021 10:36:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition; bh=itfVnMPvmrJ2NsehZzvMHu8ptMCf86ESb1eCu3uJO/8=; b=sMsjiTiE4bXgP8XZ9zbFt3/FqscgaCxqLPaPAoSlvXjmINHgzVQjD5Q/EHfjOyjxXX kkuUyqJhQ5ddY/DOKj8DZy79nAy4Q02aQuhdWNc3JrNekTLsbZtMxsrfpEJSa4vokuLq hPgAQxm2FZXt1K6ZRlnWaS/YMT+UklpD+MhJX0cwrATCEt1rV39aJScXa0IekfdC0jkl qHi87tGH8HixgrTDBIsjiTAoXP7wcPjm+KmagKwKchO7GDKeqPG+Xf3iiAZJa9LR2Sch fd+Xf9fYjOIlQn0jXe6onMXhFmD+6kqDNEnczWwQlW85WKhu7IWREYZRkB4WuH0p0huc Idzg== 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:mime-version :content-disposition; bh=itfVnMPvmrJ2NsehZzvMHu8ptMCf86ESb1eCu3uJO/8=; b=n02lVrm6BCp4Ko1/JR2nXvGr1raMRtKeIqci1Za8QnCuwP2+/J1IMt0y03vlLPxkfd 8quIs5OzkDDtTxt537BRxLz/5VYvNqEwUzABULHKHc5ffpvBS1e8M2BdhcgkqhdzLApA PX3aj18pbFm/Xcdnh+ULzj6/JzcYA8zS6tOGGcvyeCsAVXabLW0gEHPRe0eLPYUvZYcD NAszPCwXpgUZzB/WT/laozJP7hxQZZtVdxPmJOlv0Z6Bpi43+Q7oJClrmTc24puqz3Z0 uq7fEjYEaIPRZYOnTNpuHJspxbyn5ytLF9USvumWFxS3C/SP0votlK8wFbDBgceCFdrN 9D3g== X-Gm-Message-State: AOAM5338jbbFCCJ9Ae1pyBPpyMgbGkyYOnhQkgw/mZsuby/P2RAWEtsm sWW2N0xQwVd0z8bAsbi9OhE= X-Google-Smtp-Source: ABdhPJyJpiifaIIucKRGzfiYwZhJeSbDjmJwVHRDesaCc3E9+T7Iz7n4sIhCM+LUvYCBeHBWY1GO3Q== X-Received: by 2002:a17:906:5607:: with SMTP id f7mr4834989ejq.262.1616607408049; Wed, 24 Mar 2021 10:36:48 -0700 (PDT) Received: from LEGION ([111.119.187.57]) by smtp.gmail.com with ESMTPSA id g11sm1452028edt.35.2021.03.24.10.36.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Mar 2021 10:36:47 -0700 (PDT) Date: Wed, 24 Mar 2021 22:36:41 +0500 From: Muhammad Usama Anjum To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , "Peter Zijlstra (Intel)" , Masami Hiramatsu , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, colin.king@canonical.com, dan.carpenter@oracle.com Cc: musamaanjum@gmail.com, linux-kernel@vger.kernel.org Subject: [PATCH] x86/kprobes: Remove dead code Message-ID: <20210324173641.GA404706@LEGION> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: kernel-janitors@vger.kernel.org The condition in switch statement `opcode & 0xf0` cannot evaluate to 0xff. So this case statement will never execute. Remove it. Fixes: 6256e668b7 ("x86/kprobes: Use int3 instead of debug trap for single-step") Signed-off-by: Muhammad Usama Anjum --- arch/x86/kernel/kprobes/core.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 89d9f26785c7..3b7bcc077020 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -177,9 +177,6 @@ int can_boost(struct insn *insn, void *addr) case 0xf0: /* clear and set flags are boostable */ return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe)); - case 0xff: - /* indirect jmp is boostable */ - return X86_MODRM_REG(insn->modrm.bytes[0]) == 4; default: /* CS override prefix and call are not boostable */ return (opcode != 0x2e && opcode != 0x9a); -- 2.25.1