From patchwork Thu Feb 9 15:36:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 55014 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp406012wrn; Thu, 9 Feb 2023 07:39:47 -0800 (PST) X-Google-Smtp-Source: AK7set/aqxwjsRXVqXTsISmPZBXUzTvlASnEpqrKuDVEnpzFTRL8Ip1Jn0MBqfdOv7i+3L4tP2JO X-Received: by 2002:a50:ab01:0:b0:4a2:5f73:d3d2 with SMTP id s1-20020a50ab01000000b004a25f73d3d2mr12087740edc.41.1675957187651; Thu, 09 Feb 2023 07:39:47 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1675957187; cv=none; d=google.com; s=arc-20160816; b=E1vA3TKRrByAyCFGhGmbLrazkNnTSqXE/51qZHp9DEfKYN+AWXY5rSmgHWFDUOAEzx tpXClKB597PIne2ujQoAPJJK/jhC87ewHXM1qg2jLiF/TY4xLtK+CkPnbiGsBMZa1bLy pPu2hCRFIkUsm3zQpfzR6fMMKIhkjA5eU0s1hEkk7csehcZM7P31TSzS3dbnA0yx7kGp XRJwkRHSTuvTZXXMLwelNmZYOwfloWwwEhmHI2A1X8q5G/31freIsG9YTKbQs0zyfhOp MwYS/iTP5LHwi0tMRAUChMDvWlKDYAW5mzNppPb4Cw5MrjTND0uH0LbNJ/fCj+Ud565D STtw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:message-id:date:subject:cc:to:from:dkim-signature; bh=5OdFSpvWFGSgJN0HaOm7a/g2qt6jiZ9wCUrMnUr7Se0=; b=WaOWkl/3phnOSaDZl8vdMwSsbjjuqfnPkX3cb4smr7V4Xuz4rGViCX9bxgdNX+ALbE x1q13mxt/FUGVj7jTEM4pFzFjsoOdwLFTZ2gZU/FMRANAJdbzc+EP7zIyxOKD2e1NZBq 724xOX5S85vtVEQAvMUquOOUQespCkag22Wo7yDQxUTAC9qqznE+GkbHm6sPC7wrUCvg sco7GkFLepsqPsW/+2ILtnxJktKZ3czEgnuXuRH1AKqszGOrXdAmM/2ncU0SLuWn/lLR Md3LddROySmD3nJ3+YDPEDYlww/eixRP2djLLul2hdrb7xgOdJy+k7azFAnKryslp/9l p9VA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=U4AkSmo7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id p17-20020a056402075100b004ab2553d849si568681edy.201.2023.02.09.07.39.23; Thu, 09 Feb 2023 07:39:47 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=U4AkSmo7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231279AbjBIPhm (ORCPT + 99 others); Thu, 9 Feb 2023 10:37:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230331AbjBIPhk (ORCPT ); Thu, 9 Feb 2023 10:37:40 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD6E863136 for ; Thu, 9 Feb 2023 07:37:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 16287B82193 for ; Thu, 9 Feb 2023 15:36:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A59FC433D2; Thu, 9 Feb 2023 15:36:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675957000; bh=gHYGLHg1aB0ik45JC+4zloo1eDdi2WUI1kKJrxICvNI=; h=From:To:Cc:Subject:Date:From; b=U4AkSmo7WhLntlQo82gyxHgscJ70CK/zQRakf0C8DdZHYsAWBIIPjcQpBcU/pBt4n 0W9FmAVjgqkRgkzDP6EngmkXLngTBCVZz7e4ysvdebw+b2njayu6BjiacCBW1cn8MT JfoJ65IwMJ3/1uSV7BhCgtoUGAVSKjwaaHwXnE8ndDQJ9TV03iTOD8inzQrOAB2jHs xb4Gw9LBR84PxzKxutQFnJEkPS1oWCpVPzlCgA0ZgXHBhNMw1f2SlRiN9SFJzmEkvw aNwyZiPkHgdIG1b5jlSxexrCs9+2PodSEYdTBxEQyPShDcsbHJIs1uP6OkPsO9OqxV jyM0QLnVFnU2g== From: "Masami Hiramatsu (Google)" To: x86@kernel.org Cc: Nadav Amit , Borislav Petkov , Peter Zijlstra , Steven Rostedt , Masami Hiramatsu , linux-kernel@vger.kernel.org Subject: [PATCH -tip] kprobes/x86: Remove unneeded casting from immediate value Date: Fri, 10 Feb 2023 00:36:36 +0900 Message-Id: <167595699689.1303232.13460109151246012198.stgit@mhiramat.roam.corp.google.com> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog User-Agent: StGit/0.19 MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1757368484079266751?= X-GMAIL-MSGID: =?utf-8?q?1757368484079266751?= From: Masami Hiramatsu (Google) Remove unneeded casting from immediate value assignments for relative jump offset. Since the immediate values in the 'insn' data structure are assigned from immediate bytes as a signed value to insn.immediate.value by insn_field_set(). Thus, if we need to access that value as a signed value (in this kprobe's case), we don't need to cast it. This is a kind of clean up (should not change behavior) follows Nadav's bugfix. Link: https://lore.kernel.org/all/20230208071708.4048-1-namit@vmware.com/ Signed-off-by: Masami Hiramatsu (Google) Acked-by: Peter Zijlstra (Intel) --- arch/x86/kernel/kprobes/core.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 695873c0f50b..2440e736d0e4 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -607,19 +607,19 @@ static int prepare_emulation(struct kprobe *p, struct insn *insn) case 0xe8: /* near call relative */ p->ainsn.emulate_op = kprobe_emulate_call; if (insn->immediate.nbytes == 2) - p->ainsn.rel32 = *(s16 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; else - p->ainsn.rel32 = *(s32 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; break; case 0xeb: /* short jump relative */ case 0xe9: /* near jump relative */ p->ainsn.emulate_op = kprobe_emulate_jmp; if (insn->immediate.nbytes == 1) - p->ainsn.rel32 = *(s8 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; else if (insn->immediate.nbytes == 2) - p->ainsn.rel32 = *(s16 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; else - p->ainsn.rel32 = *(s32 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; break; case 0x70 ... 0x7f: /* 1 byte conditional jump */ @@ -634,9 +634,9 @@ static int prepare_emulation(struct kprobe *p, struct insn *insn) p->ainsn.emulate_op = kprobe_emulate_jcc; p->ainsn.jcc.type = opcode & 0xf; if (insn->immediate.nbytes == 2) - p->ainsn.rel32 = *(s16 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; else - p->ainsn.rel32 = *(s32 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; } else if (opcode == 0x01 && X86_MODRM_REG(insn->modrm.bytes[0]) == 0 && X86_MODRM_MOD(insn->modrm.bytes[0]) == 3) { @@ -651,7 +651,7 @@ static int prepare_emulation(struct kprobe *p, struct insn *insn) p->ainsn.emulate_op = kprobe_emulate_loop; p->ainsn.loop.type = opcode & 0x3; p->ainsn.loop.asize = insn->addr_bytes * 8; - p->ainsn.rel32 = *(s8 *)&insn->immediate.value; + p->ainsn.rel32 = insn->immediate.value; break; case 0xff: /*