Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756952Ab0BBTBK (ORCPT ); Tue, 2 Feb 2010 14:01:10 -0500 Received: from verein.lst.de ([213.95.11.210]:38059 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932110Ab0BBTA5 (ORCPT ); Tue, 2 Feb 2010 14:00:57 -0500 Date: Tue, 2 Feb 2010 20:00:42 +0100 From: Christoph Hellwig To: roland@redhat.com, oleg@redhat.com, akpm@linux-foundation.org, starvik@axis.com, jesper.nilsson@axis.com Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: [PATCH, RFC 13/14] cris arch-v32: use generic ptrace_resume code Message-ID: <20100202190042.GM3630@lst.de> References: <20100202185755.GA3630@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100202185755.GA3630@lst.de> User-Agent: Mutt/1.3.28i X-Spam-Score: 0 () Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5111 Lines: 170 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. The way breakpoints are disabled is entirely inconsistent currently, I tried to make some sense of it, but I suspect all of the content of ptrace_disable should be moved into user_disable_single_step, this defintively needs some revisting as the current patch changes behaviour in not quite designed ways. Signed-off-by: Christoph Hellwig Index: linux-2.6/arch/cris/arch-v32/kernel/ptrace.c =================================================================== --- linux-2.6.orig/arch/cris/arch-v32/kernel/ptrace.c 2010-02-02 19:23:12.314003057 +0100 +++ linux-2.6/arch/cris/arch-v32/kernel/ptrace.c 2010-02-02 19:25:27.396253967 +0100 @@ -78,6 +78,35 @@ int put_reg(struct task_struct *task, un return 0; } +void user_enable_single_step(struct task_struct *child) +{ + unsigned long tmp; + + /* + * Set up SPC if not set already (in which case we have no other + * choice but to trust it). + */ + if (!get_reg(child, PT_SPC)) { + /* In case we're stopped in a delay slot. */ + tmp = get_reg(child, PT_ERP) & ~1; + put_reg(child, PT_SPC, tmp); + } + tmp = get_reg(child, PT_CCS) | SBIT_USER; + put_reg(child, PT_CCS, tmp); +} + +void user_disable_single_step(struct task_struct *child) +{ + put_reg(child, PT_SPC, 0); + + if (!get_debugreg(child->pid, PT_BP_CTRL)) { + unsigned long tmp; + /* If no h/w bp configured, disable S bit. */ + tmp = get_reg(child, PT_CCS) & ~SBIT_USER; + put_reg(child, PT_CCS, tmp); + } +} + /* * Called by kernel/ptrace.c when detaching. * @@ -89,8 +118,7 @@ ptrace_disable(struct task_struct *child unsigned long tmp; /* Deconfigure SPC and S-bit. */ - tmp = get_reg(child, PT_CCS) & ~SBIT_USER; - put_reg(child, PT_CCS, tmp); + user_disable_single_step(child); put_reg(child, PT_SPC, 0); /* Deconfigure any watchpoints associated with the child. */ @@ -163,83 +191,6 @@ long arch_ptrace(struct task_struct *chi ret = 0; break; - case PTRACE_SYSCALL: - case PTRACE_CONT: - ret = -EIO; - - if (!valid_signal(data)) - break; - - /* Continue means no single-step. */ - put_reg(child, PT_SPC, 0); - - if (!get_debugreg(child->pid, PT_BP_CTRL)) { - unsigned long tmp; - /* If no h/w bp configured, disable S bit. */ - tmp = get_reg(child, PT_CCS) & ~SBIT_USER; - put_reg(child, PT_CCS, tmp); - } - - 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; - - /* TODO: make sure any pending breakpoint is killed */ - wake_up_process(child); - ret = 0; - - break; - - /* Make the child exit by sending it a sigkill. */ - case PTRACE_KILL: - ret = 0; - - if (child->exit_state == EXIT_ZOMBIE) - break; - - child->exit_code = SIGKILL; - - /* Deconfigure single-step and h/w bp. */ - ptrace_disable(child); - - /* TODO: make sure any pending breakpoint is killed */ - wake_up_process(child); - break; - - /* Set the trap flag. */ - case PTRACE_SINGLESTEP: { - unsigned long tmp; - ret = -EIO; - - /* Set up SPC if not set already (in which case we have - no other choice but to trust it). */ - if (!get_reg(child, PT_SPC)) { - /* In case we're stopped in a delay slot. */ - tmp = get_reg(child, PT_ERP) & ~1; - put_reg(child, PT_SPC, tmp); - } - tmp = get_reg(child, PT_CCS) | SBIT_USER; - put_reg(child, PT_CCS, tmp); - - if (!valid_signal(data)) - break; - - clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); - - /* TODO: set some clever breakpoint mechanism... */ - - child->exit_code = data; - wake_up_process(child); - ret = 0; - break; - - } - /* Get all GP registers from the child. */ case PTRACE_GETREGS: { int i; Index: linux-2.6/arch/cris/include/arch-v32/arch/ptrace.h =================================================================== --- linux-2.6.orig/arch/cris/include/arch-v32/arch/ptrace.h 2010-02-02 19:25:39.092254418 +0100 +++ linux-2.6/arch/cris/include/arch-v32/arch/ptrace.h 2010-02-02 19:25:46.173254455 +0100 @@ -108,6 +108,7 @@ struct switch_stack { #ifdef __KERNEL__ +#define arch_has_single_step() (1) #define user_mode(regs) (((regs)->ccs & (1 << (U_CCS_BITNR + CCS_SHIFT))) != 0) #define instruction_pointer(regs) ((regs)->erp) extern void show_regs(struct pt_regs *); -- 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/