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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 1FB39C4332E for ; Thu, 4 Mar 2021 17:46:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 007A064F51 for ; Thu, 4 Mar 2021 17:46:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239760AbhCDRqm (ORCPT ); Thu, 4 Mar 2021 12:46:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239150AbhCDRo6 (ORCPT ); Thu, 4 Mar 2021 12:44:58 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55883C0613D7 for ; Thu, 4 Mar 2021 09:42:58 -0800 (PST) Received: from zn.tnic (p200300ec2f0f5900f7833063514d8659.dip0.t-ipconnect.de [IPv6:2003:ec:2f0f:5900:f783:3063:514d:8659]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id E11111EC04E2; Thu, 4 Mar 2021 18:42:56 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1614879777; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8F4dFmJaJgP31TleGCXlkiVgHt5KnRoVyOa1IqQ26Do=; b=NeHcgyCJJgLL3JCfR8knOM1ZTXiqkzi9gX6b3e5Gy+nKkm8L8tvCW3V2M96sOyKm5pJlE6 VS803FozKkohK2IkyB9R7Q0PcfIVG+Cs///KkNuPvy3L9QyHgTzkS9GDv/di3WoZGXJME9 v2l+9WXplR5uf7sMVV0LsDr56EkVPfo= From: Borislav Petkov To: X86 ML Cc: Masami Hiramatsu , LKML Subject: [PATCH v3 11/21] x86/kprobes: Convert to insn_decode() Date: Thu, 4 Mar 2021 18:42:27 +0100 Message-Id: <20210304174237.31945-12-bp@alien8.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210304174237.31945-1-bp@alien8.de> References: <20210304174237.31945-1-bp@alien8.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov Simplify code, improve decoding error checking. Signed-off-by: Borislav Petkov Acked-by: Masami Hiramatsu --- arch/x86/kernel/kprobes/core.c | 17 +++++++++++------ arch/x86/kernel/kprobes/opt.c | 9 +++++++-- 2 files changed, 18 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index df776cdca327..60a540fcbd56 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -265,6 +265,8 @@ static int can_probe(unsigned long paddr) /* Decode instructions */ addr = paddr - offset; while (addr < paddr) { + int ret; + /* * Check if the instruction has been modified by another * kprobe, in which case we replace the breakpoint by the @@ -276,8 +278,10 @@ static int can_probe(unsigned long paddr) __addr = recover_probed_instruction(buf, addr); if (!__addr) return 0; - kernel_insn_init(&insn, (void *)__addr, MAX_INSN_SIZE); - insn_get_length(&insn); + + ret = insn_decode(&insn, (void *)__addr, MAX_INSN_SIZE, INSN_MODE_KERN); + if (ret < 0) + return 0; /* * Another debugging subsystem might insert this breakpoint. @@ -301,8 +305,8 @@ static int can_probe(unsigned long paddr) int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) { kprobe_opcode_t buf[MAX_INSN_SIZE]; - unsigned long recovered_insn = - recover_probed_instruction(buf, (unsigned long)src); + unsigned long recovered_insn = recover_probed_instruction(buf, (unsigned long)src); + int ret; if (!recovered_insn || !insn) return 0; @@ -312,8 +316,9 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) MAX_INSN_SIZE)) return 0; - kernel_insn_init(insn, dest, MAX_INSN_SIZE); - insn_get_length(insn); + ret = insn_decode(insn, dest, MAX_INSN_SIZE, INSN_MODE_KERN); + if (ret < 0) + return 0; /* We can not probe force emulate prefixed instruction */ if (insn_has_emulate_prefix(insn)) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 08eb23074f92..4299fc865732 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -312,6 +312,8 @@ static int can_optimize(unsigned long paddr) addr = paddr - offset; while (addr < paddr - offset + size) { /* Decode until function end */ unsigned long recovered_insn; + int ret; + if (search_exception_tables(addr)) /* * Since some fixup code will jumps into this function, @@ -321,8 +323,11 @@ static int can_optimize(unsigned long paddr) recovered_insn = recover_probed_instruction(buf, addr); if (!recovered_insn) return 0; - kernel_insn_init(&insn, (void *)recovered_insn, MAX_INSN_SIZE); - insn_get_length(&insn); + + ret = insn_decode(&insn, (void *)recovered_insn, MAX_INSN_SIZE, INSN_MODE_KERN); + if (ret < 0) + return 0; + /* * In the case of detecting unknown breakpoint, this could be * a padding INT3 between functions. Let's check that all the -- 2.29.2