From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750965AbdE2RQp (ORCPT ); Mon, 29 May 2017 13:16:45 -0400 Received: from mx2.suse.de ([195.135.220.15]:38586 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750844AbdE2RQn (ORCPT ); Mon, 29 May 2017 13:16:43 -0400 Date: Mon, 29 May 2017 19:16:25 +0200 From: Borislav Petkov To: Ricardo Neri Cc: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Brian Gerst , Chris Metcalf , Dave Hansen , Paolo Bonzini , Masami Hiramatsu , Huang Rui , Jiri Slaby , Jonathan Corbet , "Michael S. Tsirkin" , Paul Gortmaker , Vlastimil Babka , Chen Yucong , Alexandre Julliard , Stas Sergeev , Fenghua Yu , "Ravi V. Shankar" , Shuah Khan , linux-kernel@vger.kernel.org, x86@kernel.org, linux-msdos@vger.kernel.org, wine-devel@winehq.org, Adam Buchbinder , Colin Ian King , Lorenzo Stoakes , Qiaowei Ren , Arnaldo Carvalho de Melo , Adrian Hunter , Kees Cook , Thomas Garnier , Dmitry Vyukov Subject: Re: [PATCH v7 08/26] x86/insn-eval: Add a utility function to get register offsets Message-ID: <20170529171624.ai7cni33lpddaoed@pd.tnic> References: <20170505181724.55000-1-ricardo.neri-calderon@linux.intel.com> <20170505181724.55000-9-ricardo.neri-calderon@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170505181724.55000-9-ricardo.neri-calderon@linux.intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 05, 2017 at 11:17:06AM -0700, Ricardo Neri wrote: > The function get_reg_offset() returns the offset to the register the > argument specifies as indicated in an enumeration of type offset. Callers > of this function would need the definition of such enumeration. This is > not needed. Instead, add helper functions for this purpose. These functions > are useful in cases when, for instance, the caller needs to decide whether > the operand is a register or a memory location by looking at the rm part > of the ModRM byte. As of now, this is the only helper function that is > needed. > > Cc: Dave Hansen > Cc: Adam Buchbinder > Cc: Colin Ian King > Cc: Lorenzo Stoakes > Cc: Qiaowei Ren > Cc: Arnaldo Carvalho de Melo > Cc: Masami Hiramatsu > Cc: Adrian Hunter > Cc: Kees Cook > Cc: Thomas Garnier > Cc: Peter Zijlstra > Cc: Borislav Petkov > Cc: Dmitry Vyukov > Cc: Ravi V. Shankar > Cc: x86@kernel.org > Signed-off-by: Ricardo Neri > --- > arch/x86/include/asm/insn-eval.h | 1 + > arch/x86/lib/insn-eval.c | 15 +++++++++++++++ > 2 files changed, 16 insertions(+) > > diff --git a/arch/x86/include/asm/insn-eval.h b/arch/x86/include/asm/insn-eval.h > index 5cab1b1..7e8c963 100644 > --- a/arch/x86/include/asm/insn-eval.h > +++ b/arch/x86/include/asm/insn-eval.h > @@ -12,5 +12,6 @@ > #include > > 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); > > #endif /* _ASM_X86_INSN_EVAL_H */ > diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c > index 182e2ae..8b16761 100644 > --- a/arch/x86/lib/insn-eval.c > +++ b/arch/x86/lib/insn-eval.c > @@ -97,6 +97,21 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, > return regoff[regno]; > } > > +/** > + * insn_get_reg_offset_modrm_rm() - Obtain register in r/m part of ModRM byte That name needs to be synced with the function name below. > + * @insn: Instruction structure containing the ModRM byte > + * @regs: Structure with register values as seen when entering kernel mode > + * > + * Return: The register indicated by the r/m part of the ModRM byte. The > + * register is obtained as an offset from the base of pt_regs. In specific > + * cases, the returned value can be -EDOM to indicate that the particular value > + * of ModRM does not refer to a register and shall be ignored. > + */ > +int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs) ^^^^^^^^^^^^^^^^^^^^ -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --