From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243AbdJLQbz (ORCPT ); Thu, 12 Oct 2017 12:31:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:54494 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751040AbdJLQby (ORCPT ); Thu, 12 Oct 2017 12:31:54 -0400 Date: Thu, 12 Oct 2017 18:31:41 +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 , "Ravi V. Shankar" , Shuah Khan , linux-kernel@vger.kernel.org, x86@kernel.org, ricardo.neri@intel.com, Adam Buchbinder , Colin Ian King , Lorenzo Stoakes , Qiaowei Ren , Arnaldo Carvalho de Melo , Adrian Hunter , Kees Cook , Thomas Garnier , Dmitry Vyukov Subject: Re: [PATCH v9 16/29] x86/insn-eval: Add function to get default params of code segment Message-ID: <20171012163141.mekj5hemwtkpxh32@pd.tnic> References: <1507089272-32733-1-git-send-email-ricardo.neri-calderon@linux.intel.com> <1507089272-32733-17-git-send-email-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: <1507089272-32733-17-git-send-email-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 Tue, Oct 03, 2017 at 08:54:19PM -0700, Ricardo Neri wrote: > Obtain the default values of the address and operand sizes as specified in > the D and L bits of the the segment descriptor selected by the register > CS. The function can be used for both protected and long modes. > For virtual-8086 mode, the default address and operand sizes are always 2 > bytes. > > The returned parameters are encoded in a signed 8-bit data type. Auxiliar > macros are provided to encode and decode such values. > > 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 | 5 ++++ > arch/x86/lib/insn-eval.c | 64 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 69 insertions(+) Some cleanups ontop: --- diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 64924b7d5fff..3352b9d5164f 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -614,14 +614,14 @@ static unsigned long get_seg_limit(struct pt_regs *regs, int seg_reg_idx) } /** - * insn_get_code_seg_defaults() - Obtain code segment default parameters + * insn_get_code_seg_params() - Obtain code segment parameters * @regs: Structure with register values as seen when entering kernel mode * - * Obtain the default parameters of the code segment: address and operand sizes. - * The code segment is obtained from the selector contained in the CS register - * in regs. In protected mode, the default address is determined by inspecting - * the L and D bits of the segment descriptor. In virtual-8086 mode, the default - * is always two bytes for both address and operand sizes. + * Obtain address and operand sizes of the code segment. It is obtained from the + * selector contained in the CS register in regs. In protected mode, the default + * address is determined by inspecting the L and D bits of the segment descriptor. + * In virtual-8086 mode, the default is always two bytes for both address and + * operand sizes. * * Returns: * @@ -629,7 +629,7 @@ static unsigned long get_seg_limit(struct pt_regs *regs, int seg_reg_idx) * * -EINVAL on error. */ -char insn_get_code_seg_defaults(struct pt_regs *regs) +char insn_get_code_seg_params(struct pt_regs *regs) { struct desc_struct *desc; short sel; @@ -640,7 +640,7 @@ char insn_get_code_seg_defaults(struct pt_regs *regs) sel = get_segment_selector(regs, INAT_SEG_REG_CS); if (sel < 0) - return -1L; + return sel; desc = get_desc(sel); if (!desc) -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --