From patchwork Mon Sep 7 13:15:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 11761707 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5E12715AB for ; Mon, 7 Sep 2020 17:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FA452137B for ; Mon, 7 Sep 2020 17:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731304AbgIGRcg (ORCPT ); Mon, 7 Sep 2020 13:32:36 -0400 Received: from 8bytes.org ([81.169.241.247]:43572 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729478AbgIGNS0 (ORCPT ); Mon, 7 Sep 2020 09:18:26 -0400 Received: from cap.home.8bytes.org (p549add56.dip0.t-ipconnect.de [84.154.221.86]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id 4EFC4D3B; Mon, 7 Sep 2020 15:16:47 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Cc: Joerg Roedel , Joerg Roedel , Masami Hiramatsu , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Mike Stunes , Sean Christopherson , Martin Radev , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v7 10/72] x86/insn: Add insn_get_modrm_reg_off() Date: Mon, 7 Sep 2020 15:15:11 +0200 Message-Id: <20200907131613.12703-11-joro@8bytes.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200907131613.12703-1-joro@8bytes.org> References: <20200907131613.12703-1-joro@8bytes.org> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Joerg Roedel Add a function to the instruction decoder which returns the pt_regs offset of the register specified in the reg field of the modrm byte. Signed-off-by: Joerg Roedel Acked-by: Masami Hiramatsu --- arch/x86/include/asm/insn-eval.h | 1 + arch/x86/lib/insn-eval.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/arch/x86/include/asm/insn-eval.h b/arch/x86/include/asm/insn-eval.h index 392b4fe377f9..f748f57f1491 100644 --- a/arch/x86/include/asm/insn-eval.h +++ b/arch/x86/include/asm/insn-eval.h @@ -17,6 +17,7 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs); int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs); +int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs); unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx); int insn_get_code_seg_params(struct pt_regs *regs); int insn_fetch_from_user(struct pt_regs *regs, diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 2323c85132cf..f20942ce76c6 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -20,6 +20,7 @@ enum reg_type { REG_TYPE_RM = 0, + REG_TYPE_REG, REG_TYPE_INDEX, REG_TYPE_BASE, }; @@ -439,6 +440,13 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, regno += 8; break; + case REG_TYPE_REG: + regno = X86_MODRM_REG(insn->modrm.value); + + if (X86_REX_R(insn->rex_prefix.value)) + regno += 8; + break; + case REG_TYPE_INDEX: regno = X86_SIB_INDEX(insn->sib.value); if (X86_REX_X(insn->rex_prefix.value)) @@ -807,6 +815,21 @@ int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs) return get_reg_offset(insn, regs, REG_TYPE_RM); } +/** + * insn_get_modrm_reg_off() - Obtain register in reg part of the ModRM byte + * @insn: Instruction containing the ModRM byte + * @regs: Register values as seen when entering kernel mode + * + * Returns: + * + * The register indicated by the reg part of the ModRM byte. The + * register is obtained as an offset from the base of pt_regs. + */ +int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs) +{ + return get_reg_offset(insn, regs, REG_TYPE_REG); +} + /** * get_seg_base_limit() - obtain base address and limit of a segment * @insn: Instruction. Must be valid.