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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 B5FDCC43613 for ; Mon, 24 Jun 2019 09:57:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 883C320679 for ; Mon, 24 Jun 2019 09:57:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728827AbfFXJ5P (ORCPT ); Mon, 24 Jun 2019 05:57:15 -0400 Received: from foss.arm.com ([217.140.110.172]:44918 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728638AbfFXJ4V (ORCPT ); Mon, 24 Jun 2019 05:56:21 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BA46D106F; Mon, 24 Jun 2019 02:56:20 -0700 (PDT) Received: from e121650-lin.cambridge.arm.com (e121650-lin.cambridge.arm.com [10.1.196.120]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9C54A3F71E; Mon, 24 Jun 2019 02:56:19 -0700 (PDT) From: Raphael Gault To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: jpoimboe@redhat.com, peterz@infradead.org, catalin.marinas@arm.com, will.deacon@arm.com, julien.thierry@arm.com, Raphael Gault Subject: [RFC V3 07/18] objtool: Introduce INSN_UNKNOWN type Date: Mon, 24 Jun 2019 10:55:37 +0100 Message-Id: <20190624095548.8578-8-raphael.gault@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190624095548.8578-1-raphael.gault@arm.com> References: <20190624095548.8578-1-raphael.gault@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On arm64 some object files contain data stored in the .text section. This data is interpreted by objtool as instruction but can't be identified as a valid one. In order to keep analysing those files we introduce INSN_UNKNOWN type. The "unknown instruction" warning will thus only be raised if such instructions are uncountered while validating an execution branch. This change doesn't impact the x86 decoding logic since 0 is still used as a way to specify an unknown type, raising the "unknown instruction" warning during the decoding phase still. Signed-off-by: Raphael Gault --- tools/objtool/arch.h | 3 ++- tools/objtool/arch/arm64/decode.c | 8 ++++---- tools/objtool/arch/arm64/include/insn_decode.h | 4 ++-- tools/objtool/check.c | 10 +++++++++- 4 files changed, 17 insertions(+), 8 deletions(-) diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h index 723600aae13f..f3f94e2a1403 100644 --- a/tools/objtool/arch.h +++ b/tools/objtool/arch.h @@ -26,7 +26,8 @@ #define INSN_CLAC 12 #define INSN_STD 13 #define INSN_CLD 14 -#define INSN_OTHER 15 +#define INSN_UNKNOWN 15 +#define INSN_OTHER 16 #define INSN_LAST INSN_OTHER enum op_dest_type { diff --git a/tools/objtool/arch/arm64/decode.c b/tools/objtool/arch/arm64/decode.c index 5be1d87b1a1c..a40338a895f5 100644 --- a/tools/objtool/arch/arm64/decode.c +++ b/tools/objtool/arch/arm64/decode.c @@ -37,9 +37,9 @@ */ static arm_decode_class aarch64_insn_class_decode_table[] = { [INSN_RESERVED] = arm_decode_reserved, - [INSN_UNKNOWN] = arm_decode_unknown, + [INSN_UNALLOC_1] = arm_decode_unknown, [INSN_SVE_ENC] = arm_decode_sve_encoding, - [INSN_UNALLOC] = arm_decode_unknown, + [INSN_UNALLOC_2] = arm_decode_unknown, [INSN_LD_ST_4] = arm_decode_ld_st, [INSN_DP_REG_5] = arm_decode_dp_reg, [INSN_LD_ST_6] = arm_decode_ld_st, @@ -191,7 +191,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, int arm_decode_unknown(u32 instr, unsigned char *type, unsigned long *immediate, struct stack_op *op) { - *type = 0; + *type = INSN_UNKNOWN; return 0; } @@ -206,7 +206,7 @@ int arm_decode_reserved(u32 instr, unsigned char *type, unsigned long *immediate, struct stack_op *op) { *immediate = instr & ONES(16); - *type = INSN_BUG; + *type = INSN_UNKNOWN; return 0; } diff --git a/tools/objtool/arch/arm64/include/insn_decode.h b/tools/objtool/arch/arm64/include/insn_decode.h index eb54fc39dca5..a01d76306749 100644 --- a/tools/objtool/arch/arm64/include/insn_decode.h +++ b/tools/objtool/arch/arm64/include/insn_decode.h @@ -20,9 +20,9 @@ #include "../../../arch.h" #define INSN_RESERVED 0b0000 -#define INSN_UNKNOWN 0b0001 +#define INSN_UNALLOC_1 0b0001 #define INSN_SVE_ENC 0b0010 -#define INSN_UNALLOC 0b0011 +#define INSN_UNALLOC_2 0b0011 #define INSN_DP_IMM 0b1001 //0x100x #define INSN_BRANCH 0b1011 //0x101x #define INSN_LD_ST_4 0b0100 //0bx1x0 diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 3172f49c3a58..cba1d91451cc 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1952,6 +1952,13 @@ static int validate_branch(struct objtool_file *file, struct instruction *first, while (1) { next_insn = next_insn_same_sec(file, insn); + if (insn->type == INSN_UNKNOWN) { + WARN("%s+0x%lx unknown instruction type, should never be reached", + insn->sec->name, + insn->offset); + return 1; + } + if (file->c_file && func && insn->func && func != insn->func->pfunc) { WARN("%s() falls through to next function %s()", func->name, insn->func->name); @@ -2383,7 +2390,8 @@ static int validate_reachable_instructions(struct objtool_file *file) return 0; for_each_insn(file, insn) { - if (insn->visited || ignore_unreachable_insn(insn)) + if (insn->visited || ignore_unreachable_insn(insn) || + insn->type == INSN_UNKNOWN) continue; WARN_FUNC("unreachable instruction", insn->sec, insn->offset); -- 2.17.1