| /* | 
 |  * arch/sh/kernel/ptrace_64.c | 
 |  * | 
 |  * Copyright (C) 2000, 2001  Paolo Alberelli | 
 |  * Copyright (C) 2003 - 2008  Paul Mundt | 
 |  * | 
 |  * Started from SH3/4 version: | 
 |  *   SuperH version:   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka | 
 |  * | 
 |  *   Original x86 implementation: | 
 |  *	By Ross Biro 1/23/92 | 
 |  *	edited by Linus Torvalds | 
 |  * | 
 |  * This file is subject to the terms and conditions of the GNU General Public | 
 |  * License.  See the file "COPYING" in the main directory of this archive | 
 |  * for more details. | 
 |  */ | 
 | #include <linux/kernel.h> | 
 | #include <linux/rwsem.h> | 
 | #include <linux/sched.h> | 
 | #include <linux/mm.h> | 
 | #include <linux/smp.h> | 
 | #include <linux/bitops.h> | 
 | #include <linux/errno.h> | 
 | #include <linux/ptrace.h> | 
 | #include <linux/user.h> | 
 | #include <linux/signal.h> | 
 | #include <linux/syscalls.h> | 
 | #include <linux/audit.h> | 
 | #include <linux/seccomp.h> | 
 | #include <linux/tracehook.h> | 
 | #include <linux/elf.h> | 
 | #include <linux/regset.h> | 
 | #include <asm/io.h> | 
 | #include <asm/uaccess.h> | 
 | #include <asm/pgtable.h> | 
 | #include <asm/processor.h> | 
 | #include <asm/mmu_context.h> | 
 | #include <asm/syscalls.h> | 
 | #include <asm/fpu.h> | 
 | #include <asm/traps.h> | 
 |  | 
 | #define CREATE_TRACE_POINTS | 
 | #include <trace/events/syscalls.h> | 
 |  | 
 | /* This mask defines the bits of the SR which the user is not allowed to | 
 |    change, which are everything except S, Q, M, PR, SZ, FR. */ | 
 | #define SR_MASK      (0xffff8cfd) | 
 |  | 
 | /* | 
 |  * does not yet catch signals sent when the child dies. | 
 |  * in exit.c or in signal.c. | 
 |  */ | 
 |  | 
 | /* | 
 |  * This routine will get a word from the user area in the process kernel stack. | 
 |  */ | 
 | static inline int get_stack_long(struct task_struct *task, int offset) | 
 | { | 
 | 	unsigned char *stack; | 
 |  | 
 | 	stack = (unsigned char *)(task->thread.uregs); | 
 | 	stack += offset; | 
 | 	return (*((int *)stack)); | 
 | } | 
 |  | 
 | static inline unsigned long | 
 | get_fpu_long(struct task_struct *task, unsigned long addr) | 
 | { | 
 | 	unsigned long tmp; | 
 | 	struct pt_regs *regs; | 
 | 	regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; | 
 |  | 
 | 	if (!tsk_used_math(task)) { | 
 | 		if (addr == offsetof(struct user_fpu_struct, fpscr)) { | 
 | 			tmp = FPSCR_INIT; | 
 | 		} else { | 
 | 			tmp = 0xffffffffUL; /* matches initial value in fpu.c */ | 
 | 		} | 
 | 		return tmp; | 
 | 	} | 
 |  | 
 | 	if (last_task_used_math == task) { | 
 | 		enable_fpu(); | 
 | 		save_fpu(task); | 
 | 		disable_fpu(); | 
 | 		last_task_used_math = 0; | 
 | 		regs->sr |= SR_FD; | 
 | 	} | 
 |  | 
 | 	tmp = ((long *)task->thread.xstate)[addr / sizeof(unsigned long)]; | 
 | 	return tmp; | 
 | } | 
 |  | 
 | /* | 
 |  * This routine will put a word into the user area in the process kernel stack. | 
 |  */ | 
 | static inline int put_stack_long(struct task_struct *task, int offset, | 
 | 				 unsigned long data) | 
 | { | 
 | 	unsigned char *stack; | 
 |  | 
 | 	stack = (unsigned char *)(task->thread.uregs); | 
 | 	stack += offset; | 
 | 	*(unsigned long *) stack = data; | 
 | 	return 0; | 
 | } | 
 |  | 
 | static inline int | 
 | put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data) | 
 | { | 
 | 	struct pt_regs *regs; | 
 |  | 
 | 	regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; | 
 |  | 
 | 	if (!tsk_used_math(task)) { | 
 | 		init_fpu(task); | 
 | 	} else if (last_task_used_math == task) { | 
 | 		enable_fpu(); | 
 | 		save_fpu(task); | 
 | 		disable_fpu(); | 
 | 		last_task_used_math = 0; | 
 | 		regs->sr |= SR_FD; | 
 | 	} | 
 |  | 
 | 	((long *)task->thread.xstate)[addr / sizeof(unsigned long)] = data; | 
 | 	return 0; | 
 | } | 
 |  | 
 | void user_enable_single_step(struct task_struct *child) | 
 | { | 
 | 	struct pt_regs *regs = child->thread.uregs; | 
 |  | 
 | 	regs->sr |= SR_SSTEP;	/* auto-resetting upon exception */ | 
 |  | 
 | 	set_tsk_thread_flag(child, TIF_SINGLESTEP); | 
 | } | 
 |  | 
 | void user_disable_single_step(struct task_struct *child) | 
 | { | 
 | 	struct pt_regs *regs = child->thread.uregs; | 
 |  | 
 | 	regs->sr &= ~SR_SSTEP; | 
 |  | 
 | 	clear_tsk_thread_flag(child, TIF_SINGLESTEP); | 
 | } | 
 |  | 
 | static int genregs_get(struct task_struct *target, | 
 | 		       const struct user_regset *regset, | 
 | 		       unsigned int pos, unsigned int count, | 
 | 		       void *kbuf, void __user *ubuf) | 
 | { | 
 | 	const struct pt_regs *regs = task_pt_regs(target); | 
 | 	int ret; | 
 |  | 
 | 	/* PC, SR, SYSCALL */ | 
 | 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, | 
 | 				  ®s->pc, | 
 | 				  0, 3 * sizeof(unsigned long long)); | 
 |  | 
 | 	/* R1 -> R63 */ | 
 | 	if (!ret) | 
 | 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, | 
 | 					  regs->regs, | 
 | 					  offsetof(struct pt_regs, regs[0]), | 
 | 					  63 * sizeof(unsigned long long)); | 
 | 	/* TR0 -> TR7 */ | 
 | 	if (!ret) | 
 | 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, | 
 | 					  regs->tregs, | 
 | 					  offsetof(struct pt_regs, tregs[0]), | 
 | 					  8 * sizeof(unsigned long long)); | 
 |  | 
 | 	if (!ret) | 
 | 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, | 
 | 					       sizeof(struct pt_regs), -1); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int genregs_set(struct task_struct *target, | 
 | 		       const struct user_regset *regset, | 
 | 		       unsigned int pos, unsigned int count, | 
 | 		       const void *kbuf, const void __user *ubuf) | 
 | { | 
 | 	struct pt_regs *regs = task_pt_regs(target); | 
 | 	int ret; | 
 |  | 
 | 	/* PC, SR, SYSCALL */ | 
 | 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, | 
 | 				 ®s->pc, | 
 | 				 0, 3 * sizeof(unsigned long long)); | 
 |  | 
 | 	/* R1 -> R63 */ | 
 | 	if (!ret && count > 0) | 
 | 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, | 
 | 					 regs->regs, | 
 | 					 offsetof(struct pt_regs, regs[0]), | 
 | 					 63 * sizeof(unsigned long long)); | 
 |  | 
 | 	/* TR0 -> TR7 */ | 
 | 	if (!ret && count > 0) | 
 | 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, | 
 | 					 regs->tregs, | 
 | 					 offsetof(struct pt_regs, tregs[0]), | 
 | 					 8 * sizeof(unsigned long long)); | 
 |  | 
 | 	if (!ret) | 
 | 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, | 
 | 						sizeof(struct pt_regs), -1); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | #ifdef CONFIG_SH_FPU | 
 | int fpregs_get(struct task_struct *target, | 
 | 	       const struct user_regset *regset, | 
 | 	       unsigned int pos, unsigned int count, | 
 | 	       void *kbuf, void __user *ubuf) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	ret = init_fpu(target); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, | 
 | 				   &target->thread.xstate->hardfpu, 0, -1); | 
 | } | 
 |  | 
 | static int fpregs_set(struct task_struct *target, | 
 | 		       const struct user_regset *regset, | 
 | 		       unsigned int pos, unsigned int count, | 
 | 		       const void *kbuf, const void __user *ubuf) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	ret = init_fpu(target); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	set_stopped_child_used_math(target); | 
 |  | 
 | 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf, | 
 | 				  &target->thread.xstate->hardfpu, 0, -1); | 
 | } | 
 |  | 
 | static int fpregs_active(struct task_struct *target, | 
 | 			 const struct user_regset *regset) | 
 | { | 
 | 	return tsk_used_math(target) ? regset->n : 0; | 
 | } | 
 | #endif | 
 |  | 
 | const struct pt_regs_offset regoffset_table[] = { | 
 | 	REG_OFFSET_NAME(pc), | 
 | 	REG_OFFSET_NAME(sr), | 
 | 	REG_OFFSET_NAME(syscall_nr), | 
 | 	REGS_OFFSET_NAME(0), | 
 | 	REGS_OFFSET_NAME(1), | 
 | 	REGS_OFFSET_NAME(2), | 
 | 	REGS_OFFSET_NAME(3), | 
 | 	REGS_OFFSET_NAME(4), | 
 | 	REGS_OFFSET_NAME(5), | 
 | 	REGS_OFFSET_NAME(6), | 
 | 	REGS_OFFSET_NAME(7), | 
 | 	REGS_OFFSET_NAME(8), | 
 | 	REGS_OFFSET_NAME(9), | 
 | 	REGS_OFFSET_NAME(10), | 
 | 	REGS_OFFSET_NAME(11), | 
 | 	REGS_OFFSET_NAME(12), | 
 | 	REGS_OFFSET_NAME(13), | 
 | 	REGS_OFFSET_NAME(14), | 
 | 	REGS_OFFSET_NAME(15), | 
 | 	REGS_OFFSET_NAME(16), | 
 | 	REGS_OFFSET_NAME(17), | 
 | 	REGS_OFFSET_NAME(18), | 
 | 	REGS_OFFSET_NAME(19), | 
 | 	REGS_OFFSET_NAME(20), | 
 | 	REGS_OFFSET_NAME(21), | 
 | 	REGS_OFFSET_NAME(22), | 
 | 	REGS_OFFSET_NAME(23), | 
 | 	REGS_OFFSET_NAME(24), | 
 | 	REGS_OFFSET_NAME(25), | 
 | 	REGS_OFFSET_NAME(26), | 
 | 	REGS_OFFSET_NAME(27), | 
 | 	REGS_OFFSET_NAME(28), | 
 | 	REGS_OFFSET_NAME(29), | 
 | 	REGS_OFFSET_NAME(30), | 
 | 	REGS_OFFSET_NAME(31), | 
 | 	REGS_OFFSET_NAME(32), | 
 | 	REGS_OFFSET_NAME(33), | 
 | 	REGS_OFFSET_NAME(34), | 
 | 	REGS_OFFSET_NAME(35), | 
 | 	REGS_OFFSET_NAME(36), | 
 | 	REGS_OFFSET_NAME(37), | 
 | 	REGS_OFFSET_NAME(38), | 
 | 	REGS_OFFSET_NAME(39), | 
 | 	REGS_OFFSET_NAME(40), | 
 | 	REGS_OFFSET_NAME(41), | 
 | 	REGS_OFFSET_NAME(42), | 
 | 	REGS_OFFSET_NAME(43), | 
 | 	REGS_OFFSET_NAME(44), | 
 | 	REGS_OFFSET_NAME(45), | 
 | 	REGS_OFFSET_NAME(46), | 
 | 	REGS_OFFSET_NAME(47), | 
 | 	REGS_OFFSET_NAME(48), | 
 | 	REGS_OFFSET_NAME(49), | 
 | 	REGS_OFFSET_NAME(50), | 
 | 	REGS_OFFSET_NAME(51), | 
 | 	REGS_OFFSET_NAME(52), | 
 | 	REGS_OFFSET_NAME(53), | 
 | 	REGS_OFFSET_NAME(54), | 
 | 	REGS_OFFSET_NAME(55), | 
 | 	REGS_OFFSET_NAME(56), | 
 | 	REGS_OFFSET_NAME(57), | 
 | 	REGS_OFFSET_NAME(58), | 
 | 	REGS_OFFSET_NAME(59), | 
 | 	REGS_OFFSET_NAME(60), | 
 | 	REGS_OFFSET_NAME(61), | 
 | 	REGS_OFFSET_NAME(62), | 
 | 	REGS_OFFSET_NAME(63), | 
 | 	TREGS_OFFSET_NAME(0), | 
 | 	TREGS_OFFSET_NAME(1), | 
 | 	TREGS_OFFSET_NAME(2), | 
 | 	TREGS_OFFSET_NAME(3), | 
 | 	TREGS_OFFSET_NAME(4), | 
 | 	TREGS_OFFSET_NAME(5), | 
 | 	TREGS_OFFSET_NAME(6), | 
 | 	TREGS_OFFSET_NAME(7), | 
 | 	REG_OFFSET_END, | 
 | }; | 
 |  | 
 | /* | 
 |  * These are our native regset flavours. | 
 |  */ | 
 | enum sh_regset { | 
 | 	REGSET_GENERAL, | 
 | #ifdef CONFIG_SH_FPU | 
 | 	REGSET_FPU, | 
 | #endif | 
 | }; | 
 |  | 
 | static const struct user_regset sh_regsets[] = { | 
 | 	/* | 
 | 	 * Format is: | 
 | 	 *	PC, SR, SYSCALL, | 
 | 	 *	R1 --> R63, | 
 | 	 *	TR0 --> TR7, | 
 | 	 */ | 
 | 	[REGSET_GENERAL] = { | 
 | 		.core_note_type	= NT_PRSTATUS, | 
 | 		.n		= ELF_NGREG, | 
 | 		.size		= sizeof(long long), | 
 | 		.align		= sizeof(long long), | 
 | 		.get		= genregs_get, | 
 | 		.set		= genregs_set, | 
 | 	}, | 
 |  | 
 | #ifdef CONFIG_SH_FPU | 
 | 	[REGSET_FPU] = { | 
 | 		.core_note_type	= NT_PRFPREG, | 
 | 		.n		= sizeof(struct user_fpu_struct) / | 
 | 				  sizeof(long long), | 
 | 		.size		= sizeof(long long), | 
 | 		.align		= sizeof(long long), | 
 | 		.get		= fpregs_get, | 
 | 		.set		= fpregs_set, | 
 | 		.active		= fpregs_active, | 
 | 	}, | 
 | #endif | 
 | }; | 
 |  | 
 | static const struct user_regset_view user_sh64_native_view = { | 
 | 	.name		= "sh64", | 
 | 	.e_machine	= EM_SH, | 
 | 	.regsets	= sh_regsets, | 
 | 	.n		= ARRAY_SIZE(sh_regsets), | 
 | }; | 
 |  | 
 | const struct user_regset_view *task_user_regset_view(struct task_struct *task) | 
 | { | 
 | 	return &user_sh64_native_view; | 
 | } | 
 |  | 
 | long arch_ptrace(struct task_struct *child, long request, | 
 | 		 unsigned long addr, unsigned long data) | 
 | { | 
 | 	int ret; | 
 | 	unsigned long __user *datap = (unsigned long __user *) data; | 
 |  | 
 | 	switch (request) { | 
 | 	/* read the word at location addr in the USER area. */ | 
 | 	case PTRACE_PEEKUSR: { | 
 | 		unsigned long tmp; | 
 |  | 
 | 		ret = -EIO; | 
 | 		if ((addr & 3) || addr < 0) | 
 | 			break; | 
 |  | 
 | 		if (addr < sizeof(struct pt_regs)) | 
 | 			tmp = get_stack_long(child, addr); | 
 | 		else if ((addr >= offsetof(struct user, fpu)) && | 
 | 			 (addr <  offsetof(struct user, u_fpvalid))) { | 
 | 			unsigned long index; | 
 | 			ret = init_fpu(child); | 
 | 			if (ret) | 
 | 				break; | 
 | 			index = addr - offsetof(struct user, fpu); | 
 | 			tmp = get_fpu_long(child, index); | 
 | 		} else if (addr == offsetof(struct user, u_fpvalid)) { | 
 | 			tmp = !!tsk_used_math(child); | 
 | 		} else { | 
 | 			break; | 
 | 		} | 
 | 		ret = put_user(tmp, datap); | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	case PTRACE_POKEUSR: | 
 |                 /* write the word at location addr in the USER area. We must | 
 |                    disallow any changes to certain SR bits or u_fpvalid, since | 
 |                    this could crash the kernel or result in a security | 
 |                    loophole. */ | 
 | 		ret = -EIO; | 
 | 		if ((addr & 3) || addr < 0) | 
 | 			break; | 
 |  | 
 | 		if (addr < sizeof(struct pt_regs)) { | 
 | 			/* Ignore change of top 32 bits of SR */ | 
 | 			if (addr == offsetof (struct pt_regs, sr)+4) | 
 | 			{ | 
 | 				ret = 0; | 
 | 				break; | 
 | 			} | 
 | 			/* If lower 32 bits of SR, ignore non-user bits */ | 
 | 			if (addr == offsetof (struct pt_regs, sr)) | 
 | 			{ | 
 | 				long cursr = get_stack_long(child, addr); | 
 | 				data &= ~(SR_MASK); | 
 | 				data |= (cursr & SR_MASK); | 
 | 			} | 
 | 			ret = put_stack_long(child, addr, data); | 
 | 		} | 
 | 		else if ((addr >= offsetof(struct user, fpu)) && | 
 | 			 (addr <  offsetof(struct user, u_fpvalid))) { | 
 | 			unsigned long index; | 
 | 			ret = init_fpu(child); | 
 | 			if (ret) | 
 | 				break; | 
 | 			index = addr - offsetof(struct user, fpu); | 
 | 			ret = put_fpu_long(child, index, data); | 
 | 		} | 
 | 		break; | 
 |  | 
 | 	case PTRACE_GETREGS: | 
 | 		return copy_regset_to_user(child, &user_sh64_native_view, | 
 | 					   REGSET_GENERAL, | 
 | 					   0, sizeof(struct pt_regs), | 
 | 					   datap); | 
 | 	case PTRACE_SETREGS: | 
 | 		return copy_regset_from_user(child, &user_sh64_native_view, | 
 | 					     REGSET_GENERAL, | 
 | 					     0, sizeof(struct pt_regs), | 
 | 					     datap); | 
 | #ifdef CONFIG_SH_FPU | 
 | 	case PTRACE_GETFPREGS: | 
 | 		return copy_regset_to_user(child, &user_sh64_native_view, | 
 | 					   REGSET_FPU, | 
 | 					   0, sizeof(struct user_fpu_struct), | 
 | 					   datap); | 
 | 	case PTRACE_SETFPREGS: | 
 | 		return copy_regset_from_user(child, &user_sh64_native_view, | 
 | 					     REGSET_FPU, | 
 | 					     0, sizeof(struct user_fpu_struct), | 
 | 					     datap); | 
 | #endif | 
 | 	default: | 
 | 		ret = ptrace_request(child, request, addr, data); | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | asmlinkage int sh64_ptrace(long request, long pid, | 
 | 			   unsigned long addr, unsigned long data) | 
 | { | 
 | #define WPC_DBRMODE 0x0d104008 | 
 | 	static unsigned long first_call; | 
 |  | 
 | 	if (!test_and_set_bit(0, &first_call)) { | 
 | 		/* Set WPC.DBRMODE to 0.  This makes all debug events get | 
 | 		 * delivered through RESVEC, i.e. into the handlers in entry.S. | 
 | 		 * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE | 
 | 		 * would normally be left set to 1, which makes debug events get | 
 | 		 * delivered through DBRVEC, i.e. into the remote gdb's | 
 | 		 * handlers.  This prevents ptrace getting them, and confuses | 
 | 		 * the remote gdb.) */ | 
 | 		printk("DBRMODE set to 0 to permit native debugging\n"); | 
 | 		poke_real_address_q(WPC_DBRMODE, 0); | 
 | 	} | 
 |  | 
 | 	return sys_ptrace(request, pid, addr, data); | 
 | } | 
 |  | 
 | static inline int audit_arch(void) | 
 | { | 
 | 	int arch = EM_SH; | 
 |  | 
 | #ifdef CONFIG_64BIT | 
 | 	arch |= __AUDIT_ARCH_64BIT; | 
 | #endif | 
 | #ifdef CONFIG_CPU_LITTLE_ENDIAN | 
 | 	arch |= __AUDIT_ARCH_LE; | 
 | #endif | 
 |  | 
 | 	return arch; | 
 | } | 
 |  | 
 | asmlinkage long long do_syscall_trace_enter(struct pt_regs *regs) | 
 | { | 
 | 	long long ret = 0; | 
 |  | 
 | 	secure_computing_strict(regs->regs[9]); | 
 |  | 
 | 	if (test_thread_flag(TIF_SYSCALL_TRACE) && | 
 | 	    tracehook_report_syscall_entry(regs)) | 
 | 		/* | 
 | 		 * Tracing decided this syscall should not happen. | 
 | 		 * We'll return a bogus call number to get an ENOSYS | 
 | 		 * error, but leave the original number in regs->regs[0]. | 
 | 		 */ | 
 | 		ret = -1LL; | 
 |  | 
 | 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) | 
 | 		trace_sys_enter(regs, regs->regs[9]); | 
 |  | 
 | 	audit_syscall_entry(audit_arch(), regs->regs[1], | 
 | 			    regs->regs[2], regs->regs[3], | 
 | 			    regs->regs[4], regs->regs[5]); | 
 |  | 
 | 	return ret ?: regs->regs[9]; | 
 | } | 
 |  | 
 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) | 
 | { | 
 | 	int step; | 
 |  | 
 | 	audit_syscall_exit(regs); | 
 |  | 
 | 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) | 
 | 		trace_sys_exit(regs, regs->regs[9]); | 
 |  | 
 | 	step = test_thread_flag(TIF_SINGLESTEP); | 
 | 	if (step || test_thread_flag(TIF_SYSCALL_TRACE)) | 
 | 		tracehook_report_syscall_exit(regs, step); | 
 | } | 
 |  | 
 | /* Called with interrupts disabled */ | 
 | asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs) | 
 | { | 
 | 	/* This is called after a single step exception (DEBUGSS). | 
 | 	   There is no need to change the PC, as it is a post-execution | 
 | 	   exception, as entry.S does not do anything to the PC for DEBUGSS. | 
 | 	   We need to clear the Single Step setting in SR to avoid | 
 | 	   continually stepping. */ | 
 | 	local_irq_enable(); | 
 | 	regs->sr &= ~SR_SSTEP; | 
 | 	force_sig(SIGTRAP, current); | 
 | } | 
 |  | 
 | /* Called with interrupts disabled */ | 
 | BUILD_TRAP_HANDLER(breakpoint) | 
 | { | 
 | 	TRAP_HANDLER_DECL; | 
 |  | 
 | 	/* We need to forward step the PC, to counteract the backstep done | 
 | 	   in signal.c. */ | 
 | 	local_irq_enable(); | 
 | 	force_sig(SIGTRAP, current); | 
 | 	regs->pc += 4; | 
 | } | 
 |  | 
 | /* | 
 |  * Called by kernel/ptrace.c when detaching.. | 
 |  * | 
 |  * Make sure single step bits etc are not set. | 
 |  */ | 
 | void ptrace_disable(struct task_struct *child) | 
 | { | 
 | 	user_disable_single_step(child); | 
 | } |