Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934395AbaDITov (ORCPT ); Wed, 9 Apr 2014 15:44:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62022 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934377AbaDITor (ORCPT ); Wed, 9 Apr 2014 15:44:47 -0400 Date: Wed, 9 Apr 2014 21:44:42 +0200 From: Oleg Nesterov To: Ingo Molnar , Srikar Dronamraju Cc: Ananth N Mavinakayanahalli , Anton Arapov , David Long , Denys Vlasenko , "Frank Ch. Eigler" , Jim Keniston , Jonathan Lebon , Masami Hiramatsu , linux-kernel@vger.kernel.org Subject: [RFC PATCH v2 6/6] uprobes/x86: Emulate rip-relative conditional "near" jmp's Message-ID: <20140409194442.GA6245@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140409194401.GA5854@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It seems that 16bit condi jmp is just 0x0f + short_jump_opc_plus_0x10. Reported-by: Jonathan Lebon Signed-off-by: Oleg Nesterov --- arch/x86/kernel/uprobes.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index ab9342a..cdad38d 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -588,6 +588,14 @@ static int ttt_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn) ttt_clear_displacement(auprobe, insn); break; + case 0x0f: + if (insn->opcode.nbytes != 2) + return -ENOSYS; + /* + * If it is a "near" conditional jmp, OPCODE2() - 0x10 matches + * OPCODE1() of the "short" jmp which checks the same condition. + */ + opc1 = OPCODE2(insn) - 0x10; default: if (!is_cond_jmp_opcode(opc1)) return -ENOSYS; -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/