Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754024AbaDYRsk (ORCPT ); Fri, 25 Apr 2014 13:48:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59777 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125AbaDYRrs (ORCPT ); Fri, 25 Apr 2014 13:47:48 -0400 Date: Fri, 25 Apr 2014 19:47:24 +0200 From: Oleg Nesterov To: Ingo Molnar Cc: Ananth N Mavinakayanahalli , Anton Arapov , David Long , Denys Vlasenko , "Frank Ch. Eigler" , Jim Keniston , Jonathan Lebon , Masami Hiramatsu , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: [PATCH 2/4] uprobes/x86: Introduce push_ret_address() Message-ID: <20140425174724.GA7969@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140425174704.GA7898@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 Extract the "push return address" code from branch_emulate_op() into the new simple helper, push_ret_address(). It will have more users. Signed-off-by: Oleg Nesterov --- arch/x86/kernel/uprobes.c | 15 ++++++++++++--- 1 files changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 37e73b6..48d2623 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -407,6 +407,17 @@ static int default_pre_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs) return 0; } +static int push_ret_address(struct pt_regs *regs, unsigned long ip) +{ + unsigned long new_sp = regs->sp - sizeof_long(); + + if (copy_to_user((void __user *)new_sp, &ip, sizeof_long())) + return -EFAULT; + + regs->sp = new_sp; + return 0; +} + /* * Adjust the return address pushed by a call insn executed out of line. */ @@ -517,7 +528,6 @@ static bool branch_emulate_op(struct arch_uprobe *auprobe, struct pt_regs *regs) unsigned long offs = (long)auprobe->branch.offs; if (branch_is_call(auprobe)) { - unsigned long new_sp = regs->sp - sizeof_long(); /* * If it fails we execute this (mangled, see the comment in * branch_clear_offset) insn out-of-line. In the likely case @@ -527,9 +537,8 @@ static bool branch_emulate_op(struct arch_uprobe *auprobe, struct pt_regs *regs) * * But there is corner case, see the comment in ->post_xol(). */ - if (copy_to_user((void __user *)new_sp, &new_ip, sizeof_long())) + if (push_ret_address(regs, new_ip)) return false; - regs->sp = new_sp; } else if (!check_jmp_cond(auprobe, regs)) { offs = 0; } -- 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/