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 Content-Length: 4696 Lines: 118 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 -- 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/