From: Christoph Hellwig Date: Wed, 10 Mar 2010 23:23:00 +0000 (-0800) Subject: cris arch-v32: use generic ptrace_resume code X-Git-Tag: v2.6.34-rc2~139 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=290ba3aef58ff21c977585ff6b687e457f80bf54 cris arch-v32: use generic ptrace_resume code 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 Cc: Oleg Nesterov Cc: Roland McGrath Cc: Mikael Starvik Cc: Jesper Nilsson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/cris/arch-v32/kernel/ptrace.c b/arch/cris/arch-v32/kernel/ptrace.c index dd40147..f4ebd1e 100644 --- a/arch/cris/arch-v32/kernel/ptrace.c +++ b/arch/cris/arch-v32/kernel/ptrace.c @@ -78,6 +78,35 @@ int put_reg(struct task_struct *task, unsigned int regno, unsigned long data) 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. */ @@ -169,83 +197,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 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; diff --git a/arch/cris/include/arch-v32/arch/ptrace.h b/arch/cris/include/arch-v32/arch/ptrace.h index 41f4e86..ffca8d0 100644 --- a/arch/cris/include/arch-v32/arch/ptrace.h +++ b/arch/cris/include/arch-v32/arch/ptrace.h @@ -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 *);