From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751800AbaDADZI (ORCPT ); Mon, 31 Mar 2014 23:25:08 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:35503 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbaDADZG (ORCPT ); Mon, 31 Mar 2014 23:25:06 -0400 Message-ID: <533A318A.2080603@hitachi.com> Date: Tue, 01 Apr 2014 12:24:58 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Oleg Nesterov Cc: Ingo Molnar , Srikar Dronamraju , Ananth N Mavinakayanahalli , David Long , Denys Vlasenko , "Frank Ch. Eigler" , Jim Keniston , Jonathan Lebon , linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/7] uprobes/x86: move the UPROBE_FIX_{RIP,IP,CALL} code at the end of pre/post hooks References: <20140331194412.GA9304@redhat.com> In-Reply-To: <20140331194412.GA9304@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2014/04/01 4:44), Oleg Nesterov wrote: > No functional changes. Preparation to simplify the review of the next > change. Just reorder the code in arch_uprobe_pre/post_xol() functions > so that UPROBE_FIX_{RIP_*,IP,CALL} logic goes to the end. > > Also change arch_uprobe_pre_xol() to use utask instead of autask, to > make the code more symmetrical with arch_uprobe_post_xol(). > > Signed-off-by: Oleg Nesterov Reviewed-by: Masami Hiramatsu Thank you! > --- > arch/x86/kernel/uprobes.c | 30 ++++++++++++++---------------- > 1 files changed, 14 insertions(+), 16 deletions(-) > > diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c > index e8d7b38..7dd65dc 100644 > --- a/arch/x86/kernel/uprobes.c > +++ b/arch/x86/kernel/uprobes.c > @@ -472,19 +472,18 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, > */ > int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) > { > - struct arch_uprobe_task *autask; > + struct uprobe_task *utask = current->utask; > > - autask = ¤t->utask->autask; > - autask->saved_trap_nr = current->thread.trap_nr; > + regs->ip = utask->xol_vaddr; > + utask->autask.saved_trap_nr = current->thread.trap_nr; > current->thread.trap_nr = UPROBE_TRAP_NR; > - regs->ip = current->utask->xol_vaddr; > - pre_xol_rip_insn(auprobe, regs, autask); > > - autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF); > + utask->autask.saved_tf = !!(regs->flags & X86_EFLAGS_TF); > regs->flags |= X86_EFLAGS_TF; > if (test_tsk_thread_flag(current, TIF_BLOCKSTEP)) > set_task_blockstep(current, false); > > + pre_xol_rip_insn(auprobe, regs, &utask->autask); > return 0; > } > > @@ -558,22 +557,13 @@ bool arch_uprobe_xol_was_trapped(struct task_struct *t) > */ > int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) > { > - struct uprobe_task *utask; > + struct uprobe_task *utask = current->utask; > long correction; > int result = 0; > > WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR); > > - utask = current->utask; > current->thread.trap_nr = utask->autask.saved_trap_nr; > - correction = (long)(utask->vaddr - utask->xol_vaddr); > - handle_riprel_post_xol(auprobe, regs, &correction); > - if (auprobe->fixups & UPROBE_FIX_IP) > - regs->ip += correction; > - > - if (auprobe->fixups & UPROBE_FIX_CALL) > - result = adjust_ret_addr(regs->sp, correction); > - > /* > * arch_uprobe_pre_xol() doesn't save the state of TIF_BLOCKSTEP > * so we can get an extra SIGTRAP if we do not clear TF. We need > @@ -584,6 +574,14 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) > else if (!(auprobe->fixups & UPROBE_FIX_SETF)) > regs->flags &= ~X86_EFLAGS_TF; > > + correction = (long)(utask->vaddr - utask->xol_vaddr); > + handle_riprel_post_xol(auprobe, regs, &correction); > + if (auprobe->fixups & UPROBE_FIX_IP) > + regs->ip += correction; > + > + if (auprobe->fixups & UPROBE_FIX_CALL) > + result = adjust_ret_addr(regs->sp, correction); > + > return result; > } > > -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com