From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757205Ab0BCEfp (ORCPT ); Tue, 2 Feb 2010 23:35:45 -0500 Received: from mail-yx0-f189.google.com ([209.85.210.189]:58268 "EHLO mail-yx0-f189.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753857Ab0BCEfn convert rfc822-to-8bit (ORCPT ); Tue, 2 Feb 2010 23:35:43 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=asR4MqoCLG8spLBc5T+oim4II11loOsYQxopHlAtEQHA9U/OPyesp/coJTVCpT2hRK tiZqb7IYd9jqcPgtpT98h99AKKGS30hIf5I9dLHSOuwIZKQlbPAXI8TWAglWfOjoWO3s yAx60srHn9S9QBWWxs0Ib5dLdZ7ZkRSyeEDYQ= MIME-Version: 1.0 In-Reply-To: <20100202185837.GB3630@lst.de> References: <20100202185755.GA3630@lst.de> <20100202185837.GB3630@lst.de> Date: Tue, 2 Feb 2010 23:35:42 -0500 Message-ID: Subject: Re: [PATCH 2/14] alpha: use generic ptrace_resume code From: Matt Turner To: Christoph Hellwig Cc: roland@redhat.com, oleg@redhat.com, akpm@linux-foundation.org, ink@jurassic.park.msu.ru, rth@twiddle.net, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 2, 2010 at 1:58 PM, Christoph Hellwig wrote: > Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT, > PTRACE_KILL and PTRACE_SINGLESTEP.  This implies defining > arch_has_single_step in and implementing the > user_enable_single_step and user_disable_single_step functions, which > also causes the breakpoint information to be cleared on fork, which > could be considered a bug fix. > > Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL > which it previously wasn't, which is consistent with all architectures > using the modern ptrace code. > > Signed-off-by: Christoph Hellwig > > Index: linux-2.6/arch/alpha/kernel/ptrace.c > =================================================================== > --- linux-2.6.orig/arch/alpha/kernel/ptrace.c   2010-02-02 11:05:03.197004058 +0100 > +++ linux-2.6/arch/alpha/kernel/ptrace.c        2010-02-02 11:07:04.091006019 +0100 > @@ -249,6 +249,17 @@ ptrace_cancel_bpt(struct task_struct * c >        return (nsaved != 0); >  } > > +void user_enable_single_step(struct task_struct *child) > +{ > +       /* Mark single stepping.  */ > +       task_thread_info(child)->bpt_nsaved = -1; > +} > + > +void user_disable_single_step(struct task_struct *child) > +{ > +       ptrace_cancel_bpt(child); > +} > + >  /* >  * Called by kernel/ptrace.c when detaching.. >  * > @@ -256,7 +267,7 @@ ptrace_cancel_bpt(struct task_struct * c >  */ >  void ptrace_disable(struct task_struct *child) >  { > -       ptrace_cancel_bpt(child); > +       user_disable_single_step(child); >  } > >  long arch_ptrace(struct task_struct *child, long request, long addr, long data) > @@ -289,52 +300,6 @@ long arch_ptrace(struct task_struct *chi >                DBG(DBG_MEM, ("poke $%ld<-%#lx\n", addr, data)); >                ret = put_reg(child, addr, data); >                break; > - > -       case PTRACE_SYSCALL: > -               /* continue and stop at next (return from) syscall */ > -       case PTRACE_CONT:    /* restart after signal. */ > -               ret = -EIO; > -               if (!valid_signal(data)) > -                       break; > -               if (request == PTRACE_SYSCALL) > -                       set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); > -               else > -                       clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); > -               child->exit_code = data; > -               /* make sure single-step breakpoint is gone. */ > -               ptrace_cancel_bpt(child); > -               wake_up_process(child); > -               ret = 0; > -               break; > - > -       /* > -        * Make the child exit.  Best I can do is send it a sigkill. > -        * perhaps it should be put in the status that it wants to > -        * exit. > -        */ > -       case PTRACE_KILL: > -               ret = 0; > -               if (child->exit_state == EXIT_ZOMBIE) > -                       break; > -               child->exit_code = SIGKILL; > -               /* make sure single-step breakpoint is gone. */ > -               ptrace_cancel_bpt(child); > -               wake_up_process(child); > -               break; > - > -       case PTRACE_SINGLESTEP:  /* execute single instruction. */ > -               ret = -EIO; > -               if (!valid_signal(data)) > -                       break; > -               /* Mark single stepping.  */ > -               task_thread_info(child)->bpt_nsaved = -1; > -               clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); > -               child->exit_code = data; > -               wake_up_process(child); > -               /* give it a chance to run. */ > -               ret = 0; > -               break; > - >        default: >                ret = ptrace_request(child, request, addr, data); >                break; > Index: linux-2.6/arch/alpha/include/asm/ptrace.h > =================================================================== > --- linux-2.6.orig/arch/alpha/include/asm/ptrace.h      2010-02-02 11:07:29.091023600 +0100 > +++ linux-2.6/arch/alpha/include/asm/ptrace.h   2010-02-02 11:07:38.645007248 +0100 > @@ -68,6 +68,7 @@ struct switch_stack { > >  #ifdef __KERNEL__ > > +#define arch_has_single_step()         (1) >  #define user_mode(regs) (((regs)->ps & 8) != 0) >  #define instruction_pointer(regs) ((regs)->pc) >  #define profile_pc(regs) instruction_pointer(regs) > Acked-by: Matt Turner