From patchwork Wed Jan 20 17:37:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 368202 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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 2D88BC433E9 for ; Wed, 20 Jan 2021 19:22:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4535233EB for ; Wed, 20 Jan 2021 19:22:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387718AbhATSrH (ORCPT ); Wed, 20 Jan 2021 13:47:07 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:53120 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387841AbhATRjx (ORCPT ); Wed, 20 Jan 2021 12:39:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611164306; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hMguHZY/sCxCSurZhMfyymWiW0UnVLAVgK8Kmo5II94=; b=SwimEIuurf362w7DdAiFG6Z9WwhdF13Urc8ZziqYsrjAjdtg1pm5C7JApYPV6KpsdxJG2b ZhA+x3itdHT4sqsnyxyeGq7n3v9f8n5hwjEuH2bNI3Nl6fTn/W/LQ3Dai2MMiYXey1ADx9 54fmPM9wLm5r7/LsZFXPZevibmckp7U= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-500-SlB0ZcMYMUyi1Ippz8oZdA-1; Wed, 20 Jan 2021 12:38:24 -0500 X-MC-Unique: SlB0ZcMYMUyi1Ippz8oZdA-1 Received: by mail-wr1-f72.google.com with SMTP id r8so11923138wro.22 for ; Wed, 20 Jan 2021 09:38:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hMguHZY/sCxCSurZhMfyymWiW0UnVLAVgK8Kmo5II94=; b=phKDsUBAVkZsQUB5f5NFxoUzYNEXJjrVXtBTW3s/wSz/DJ/l5wlpwV/RouX8cWlzKS HGlsc1epeG4eJT4jWm7mShpSMXNGqPkGRNjoSbmdf0QFOVsSDMlH9batcMvyPOVwoyoh Fx+xipl5vRAP2vcx7GbmVNfS2R8YkFDN1JOVzOOkyKL29Gt272nVelTJsQvUH8Q4kb7Y uVlX22ZbVJSOfI+18rb2jxN8U9CdUL2ZAehq1EB7m+y+Nga96dJ6+arcgr8Ts3ztjcBo Ri564w2vYu1WnYTx2IgqIu/6qRfDhk5DT2GyKU0AtC71zLEAwM+WLCj6r5KVktLaE2xK 9ToA== X-Gm-Message-State: AOAM532WmkbUHF5e426iQQyNiSBRHFSRnMReQlu9age4rXG1fcI6bcFR BD3URJQwBDcS27P6rp4IIQigXa6Zgx4myyPscXbZHoKKclCLVFn3HtEu1ieXj7HrA+EV8Eqqxse Rm1kkl+bHFN3DDu2udFvs X-Received: by 2002:a5d:5112:: with SMTP id s18mr10242710wrt.267.1611164302691; Wed, 20 Jan 2021 09:38:22 -0800 (PST) X-Google-Smtp-Source: ABdhPJwfzo6NlUcDC38dNrSR8pTXGMXlfQTTcZKajys6pTqFZqQ1R+z9gv6rpXRif0O4vIIw0NAjMg== X-Received: by 2002:a5d:5112:: with SMTP id s18mr10242694wrt.267.1611164302569; Wed, 20 Jan 2021 09:38:22 -0800 (PST) Received: from redfedo.redhat.com ([2a01:cb14:499:3d00:cd47:f651:9d80:157a]) by smtp.gmail.com with ESMTPSA id x11sm4948325wmi.4.2021.01.20.09.38.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Jan 2021 09:38:22 -0800 (PST) From: Julien Thierry To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, ardb@kernel.org, masahiroy@kernel.org, keescook@chromium.org, michal.lkml@markovi.net, jpoimboe@redhat.com, peterz@infradead.org, mark.rutland@arm.com, broonie@kernel.org, linux-efi@vger.kernel.org, linux-hardening@vger.kernel.org, Julien Thierry Subject: [RFC PATCH 08/17] objtool: arm64: Decode load/store instructions Date: Wed, 20 Jan 2021 18:37:51 +0100 Message-Id: <20210120173800.1660730-9-jthierry@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20210120173800.1660730-1-jthierry@redhat.com> References: <20210120173800.1660730-1-jthierry@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Decode load/store operations and create corresponding stack_ops for operations targetting SP or FP. Operations storing/loading multiple registers are split into separate stack_ops storing single registers. Operations modifying the base register get an additional stack_op for the register update. Since the atomic register(s) load/store + base register update gets split into multiple operations, to make sure objtool always sees a valid stack, consider store instruction to perform stack allocations (i.e. modifying the base pointer before the storing) and loads de-allocations (i.e. modifying the base pointer after the load). Signed-off-by: Julien Thierry --- tools/objtool/arch/arm64/decode.c | 127 ++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) diff --git a/tools/objtool/arch/arm64/decode.c b/tools/objtool/arch/arm64/decode.c index a4a587c400a1..1087ede67bcd 100644 --- a/tools/objtool/arch/arm64/decode.c +++ b/tools/objtool/arch/arm64/decode.c @@ -105,6 +105,40 @@ int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg) return -1; } +static struct stack_op *arm_make_store_op(enum aarch64_insn_register base, + enum aarch64_insn_register reg, + int offset) +{ + struct stack_op *op; + + op = calloc(1, sizeof(*op)); + op->dest.type = OP_DEST_REG_INDIRECT; + op->dest.reg = base; + op->dest.offset = offset; + op->src.type = OP_SRC_REG; + op->src.reg = reg; + op->src.offset = 0; + + return op; +} + +static struct stack_op *arm_make_load_op(enum aarch64_insn_register base, + enum aarch64_insn_register reg, + int offset) +{ + struct stack_op *op; + + op = calloc(1, sizeof(*op)); + op->dest.type = OP_DEST_REG; + op->dest.reg = reg; + op->dest.offset = 0; + op->src.type = OP_SRC_REG_INDIRECT; + op->src.reg = base; + op->src.offset = offset; + + return op; +} + static struct stack_op *arm_make_add_op(enum aarch64_insn_register dest, enum aarch64_insn_register src, int val) @@ -121,6 +155,94 @@ static struct stack_op *arm_make_add_op(enum aarch64_insn_register dest, return op; } +static bool arm_decode_load_store(u32 insn, enum insn_type *type, + unsigned long *immediate, + struct list_head *ops_list) +{ + enum aarch64_insn_register base; + enum aarch64_insn_register rt; + struct stack_op *op; + int size; + int offset; + + *type = INSN_OTHER; + + if (aarch64_insn_is_store_single(insn) || + aarch64_insn_is_load_single(insn)) + size = 1 << ((insn & GENMASK(31, 30)) >> 30); + else + size = 4 << ((insn >> 31) & 1); + + if (aarch64_insn_is_store_imm(insn) || aarch64_insn_is_load_imm(insn)) + *immediate = size * aarch64_insn_decode_immediate(AARCH64_INSN_IMM_12, + insn); + else if (aarch64_insn_is_store_pre(insn) || + aarch64_insn_is_load_pre(insn) || + aarch64_insn_is_store_post(insn) || + aarch64_insn_is_load_post(insn)) + *immediate = sign_extend(aarch64_insn_decode_immediate(AARCH64_INSN_IMM_9, + insn), + 9); + else if (aarch64_insn_is_stp(insn) || aarch64_insn_is_ldp(insn) || + aarch64_insn_is_stp_pre(insn) || + aarch64_insn_is_ldp_pre(insn) || + aarch64_insn_is_stp_post(insn) || + aarch64_insn_is_ldp_post(insn)) + *immediate = size * sign_extend(aarch64_insn_decode_immediate(AARCH64_INSN_IMM_7, + insn), + 7); + else + return false; + + base = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RN, insn); + if (base != AARCH64_INSN_REG_FP && base != AARCH64_INSN_REG_SP) + return true; + + offset = *immediate; + + if (aarch64_insn_is_store_pre(insn) || aarch64_insn_is_stp_pre(insn) || + aarch64_insn_is_store_post(insn) || aarch64_insn_is_stp_post(insn)) { + op = arm_make_add_op(base, base, *immediate); + list_add_tail(&op->list, ops_list); + + if (aarch64_insn_is_store_post(insn) || aarch64_insn_is_stp_post(insn)) + offset = -*immediate; + else + offset = 0; + } else if (aarch64_insn_is_load_post(insn) || aarch64_insn_is_ldp_post(insn)) { + offset = 0; + } + + /* First register */ + rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn); + if (aarch64_insn_is_store_single(insn) || + aarch64_insn_is_store_pair(insn)) + op = arm_make_store_op(base, rt, offset); + else + op = arm_make_load_op(base, rt, offset); + list_add_tail(&op->list, ops_list); + + /* Second register (if present) */ + if (aarch64_insn_is_store_pair(insn) || + aarch64_insn_is_load_pair(insn)) { + rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT2, + insn); + if (aarch64_insn_is_store_pair(insn)) + op = arm_make_store_op(base, rt, offset + size); + else + op = arm_make_load_op(base, rt, offset + size); + list_add_tail(&op->list, ops_list); + } + + if (aarch64_insn_is_load_pre(insn) || aarch64_insn_is_ldp_pre(insn) || + aarch64_insn_is_load_post(insn) || aarch64_insn_is_ldp_post(insn)) { + op = arm_make_add_op(base, base, *immediate); + list_add_tail(&op->list, ops_list); + } + + return true; +} + static void arm_decode_add_sub_imm(u32 instr, bool set_flags, enum insn_type *type, unsigned long *immediate, @@ -234,6 +356,11 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec, *type = INSN_OTHER; } break; + case AARCH64_INSN_CLS_LDST: + if (arm_decode_load_store(insn, type, immediate, ops_list)) + break; + *type = INSN_OTHER; + break; default: *type = INSN_OTHER; break;