[mirror_ubuntu-bionic-kernel.git] / arch / avr32 / kernel / ptrace.c

/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/unistd.h>
#include <linux/notifier.h>

#include <asm/traps.h>
#include <linux/uaccess.h>
#include <asm/ocd.h>
#include <asm/mmu_context.h>
#include <linux/kdebug.h>

static struct pt_regs *get_user_regs(struct task_struct *tsk)
{
	return (struct pt_regs *)((unsigned long)task_stack_page(tsk) +
				  THREAD_SIZE - sizeof(struct pt_regs));
}

void user_enable_single_step(struct task_struct *tsk)
{
	pr_debug("user_enable_single_step: pid=%u, PC=0x%08lx, SR=0x%08lx\n",
		 tsk->pid, task_pt_regs(tsk)->pc, task_pt_regs(tsk)->sr);

	/*
	 * We can't schedule in Debug mode, so when TIF_BREAKPOINT is
	 * set, the system call or exception handler will do a
	 * breakpoint to enter monitor mode before returning to
	 * userspace.
	 *
	 * The monitor code will then notice that TIF_SINGLE_STEP is
	 * set and return to userspace with single stepping enabled.
	 * The CPU will then enter monitor mode again after exactly
	 * one instruction has been executed, and the monitor code
	 * will then send a SIGTRAP to the process.
	 */
	set_tsk_thread_flag(tsk, TIF_BREAKPOINT);
	set_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
}

void user_disable_single_step(struct task_struct *child)
{
	/* XXX(hch): a no-op here seems wrong.. */
}

/*
 * Called by kernel/ptrace.c when detaching
 *
 * Make sure any single step bits, etc. are not set
 */
void ptrace_disable(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SINGLE_STEP);
	clear_tsk_thread_flag(child, TIF_BREAKPOINT);
	ocd_disable(child);
}

/*
 * Read the word at offset "offset" into the task's "struct user". We
 * actually access the pt_regs struct stored on the kernel stack.
 */
static int ptrace_read_user(struct task_struct *tsk, unsigned long offset,
			    unsigned long __user *data)
{
	unsigned long *regs;
	unsigned long value;

	if (offset & 3 || offset >= sizeof(struct user)) {
		printk("ptrace_read_user: invalid offset 0x%08lx\n", offset);
		return -EIO;
	}

	regs = (unsigned long *)get_user_regs(tsk);

	value = 0;
	if (offset < sizeof(struct pt_regs))
		value = regs[offset / sizeof(regs[0])];

	pr_debug("ptrace_read_user(%s[%u], %#lx, %p) -> %#lx\n",
		 tsk->comm, tsk->pid, offset, data, value);

	return put_user(value, data);
}

/*
 * Write the word "value" to offset "offset" into the task's "struct
 * user". We actually access the pt_regs struct stored on the kernel
 * stack.
 */
static int ptrace_write_user(struct task_struct *tsk, unsigned long offset,
			     unsigned long value)
{
	unsigned long *regs;

	pr_debug("ptrace_write_user(%s[%u], %#lx, %#lx)\n",
			tsk->comm, tsk->pid, offset, value);

	if (offset & 3 || offset >= sizeof(struct user)) {
		pr_debug("  invalid offset 0x%08lx\n", offset);
		return -EIO;
	}

	if (offset >= sizeof(struct pt_regs))
		return 0;

	regs = (unsigned long *)get_user_regs(tsk);
	regs[offset / sizeof(regs[0])] = value;

	return 0;
}

static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
{
	struct pt_regs *regs = get_user_regs(tsk);

	return copy_to_user(uregs, regs, sizeof(*regs)) ? -EFAULT : 0;
}

static int ptrace_setregs(struct task_struct *tsk, const void __user *uregs)
{
	struct pt_regs newregs;
	int ret;

	ret = -EFAULT;
	if (copy_from_user(&newregs, uregs, sizeof(newregs)) == 0) {
		struct pt_regs *regs = get_user_regs(tsk);

		ret = -EINVAL;
		if (valid_user_regs(&newregs)) {
			*regs = newregs;
			ret = 0;
		}
	}

	return ret;
}

long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	int ret;
	void __user *datap = (void __user *) data;

	switch (request) {
	/* Read the word at location addr in the child process */
	case PTRACE_PEEKTEXT:
	case PTRACE_PEEKDATA:
		ret = generic_ptrace_peekdata(child, addr, data);
		break;

	case PTRACE_PEEKUSR:
		ret = ptrace_read_user(child, addr, datap);
		break;

	/* Write the word in data at location addr */
	case PTRACE_POKETEXT:
	case PTRACE_POKEDATA:
		ret = generic_ptrace_pokedata(child, addr, data);
		break;

	case PTRACE_POKEUSR:
		ret = ptrace_write_user(child, addr, data);
		break;

	case PTRACE_GETREGS:
		ret = ptrace_getregs(child, datap);
		break;

	case PTRACE_SETREGS:
		ret = ptrace_setregs(child, datap);
		break;

	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

asmlinkage void syscall_trace(void)
{
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;
	if (!(current->ptrace & PT_PTRACED))
		return;

	/* The 0x80 provides a way for the tracing parent to
	 * distinguish between a syscall stop and SIGTRAP delivery */
	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
				 ? 0x80 : 0));

	/*
	 * this isn't the same as continuing with a signal, but it
	 * will do for normal use.  strace only continues with a
	 * signal if the stopping signal is not SIGTRAP.  -brl
	 */
	if (current->exit_code) {
		pr_debug("syscall_trace: sending signal %d to PID %u\n",
			 current->exit_code, current->pid);
		send_sig(current->exit_code, current, 1);
		current->exit_code = 0;
	}
}

/*
 * debug_trampoline() is an assembly stub which will store all user
 * registers on the stack and execute a breakpoint instruction.
 *
 * If we single-step into an exception handler which runs with
 * interrupts disabled the whole time so it doesn't have to check for
 * pending work, its return address will be modified so that it ends
 * up returning to debug_trampoline.
 *
 * If the exception handler decides to store the user context and
 * enable interrupts after all, it will restore the original return
 * address and status register value. Before it returns, it will
 * notice that TIF_BREAKPOINT is set and execute a breakpoint
 * instruction.
 */
extern void debug_trampoline(void);

asmlinkage struct pt_regs *do_debug(struct pt_regs *regs)
{
	struct thread_info	*ti;
	unsigned long		trampoline_addr;
	u32			status;
	u32			ctrl;
	int			code;

	status = ocd_read(DS);
	ti = current_thread_info();
	code = TRAP_BRKPT;

	pr_debug("do_debug: status=0x%08x PC=0x%08lx SR=0x%08lx tif=0x%08lx\n",
			status, regs->pc, regs->sr, ti->flags);

	if (!user_mode(regs)) {
		unsigned long	die_val = DIE_BREAKPOINT;

		if (status & (1 << OCD_DS_SSS_BIT))
			die_val = DIE_SSTEP;

		if (notify_die(die_val, "ptrace", regs, 0, 0, SIGTRAP)
				== NOTIFY_STOP)
			return regs;

		if ((status & (1 << OCD_DS_SWB_BIT))
				&& test_and_clear_ti_thread_flag(
					ti, TIF_BREAKPOINT)) {
			/*
			 * Explicit breakpoint from trampoline or
			 * exception/syscall/interrupt handler.
			 *
			 * The real saved regs are on the stack right
			 * after the ones we saved on entry.
			 */
			regs++;
			pr_debug("  -> TIF_BREAKPOINT done, adjusted regs:"
					"PC=0x%08lx SR=0x%08lx\n",
					regs->pc, regs->sr);
			BUG_ON(!user_mode(regs));

			if (test_thread_flag(TIF_SINGLE_STEP)) {
				pr_debug("Going to do single step...\n");
				return regs;
			}

			/*
			 * No TIF_SINGLE_STEP means we're done
			 * stepping over a syscall. Do the trap now.
			 */
			code = TRAP_TRACE;
		} else if ((status & (1 << OCD_DS_SSS_BIT))
				&& test_ti_thread_flag(ti, TIF_SINGLE_STEP)) {

			pr_debug("Stepped into something, "
					"setting TIF_BREAKPOINT...\n");
			set_ti_thread_flag(ti, TIF_BREAKPOINT);

			/*
			 * We stepped into an exception, interrupt or
			 * syscall handler. Some exception handlers
			 * don't check for pending work, so we need to
			 * set up a trampoline just in case.
			 *
			 * The exception entry code will undo the
			 * trampoline stuff if it does a full context
			 * save (which also means that it'll check for
			 * pending work later.)
			 */
			if ((regs->sr & MODE_MASK) == MODE_EXCEPTION) {
				trampoline_addr
					= (unsigned long)&debug_trampoline;

				pr_debug("Setting up trampoline...\n");
				ti->rar_saved = sysreg_read(RAR_EX);
				ti->rsr_saved = sysreg_read(RSR_EX);
				sysreg_write(RAR_EX, trampoline_addr);
				sysreg_write(RSR_EX, (MODE_EXCEPTION
							| SR_EM | SR_GM));
				BUG_ON(ti->rsr_saved & MODE_MASK);
			}

			/*
			 * If we stepped into a system call, we
			 * shouldn't do a single step after we return
			 * since the return address is right after the
			 * "scall" instruction we were told to step
			 * over.
			 */
			if ((regs->sr & MODE_MASK) == MODE_SUPERVISOR) {
				pr_debug("Supervisor; no single step\n");
				clear_ti_thread_flag(ti, TIF_SINGLE_STEP);
			}

			ctrl = ocd_read(DC);
			ctrl &= ~(1 << OCD_DC_SS_BIT);
			ocd_write(DC, ctrl);

			return regs;
		} else {
			printk(KERN_ERR "Unexpected OCD_DS value: 0x%08x\n",
					status);
			printk(KERN_ERR "Thread flags: 0x%08lx\n", ti->flags);
			die("Unhandled debug trap in kernel mode",
					regs, SIGTRAP);
		}
	} else if (status & (1 << OCD_DS_SSS_BIT)) {
		/* Single step in user mode */
		code = TRAP_TRACE;

		ctrl = ocd_read(DC);
		ctrl &= ~(1 << OCD_DC_SS_BIT);
		ocd_write(DC, ctrl);
	}

	pr_debug("Sending SIGTRAP: code=%d PC=0x%08lx SR=0x%08lx\n",
			code, regs->pc, regs->sr);

	clear_thread_flag(TIF_SINGLE_STEP);
	_exception(SIGTRAP, regs, code, instruction_pointer(regs));

	return regs;
}
Commit	Line	Data
5f97f7f9 HS	1	/*
	2	* Copyright (C) 2004-2006 Atmel Corporation
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8	#undef DEBUG
	9	#include <linux/kernel.h>
	10	#include <linux/sched.h>
68db0cf1	11	#include <linux/sched/task_stack.h>
5f97f7f9	12	#include <linux/mm.h>
5f97f7f9 HS	13	#include <linux/ptrace.h>
	14	#include <linux/errno.h>
	15	#include <linux/user.h>
	16	#include <linux/security.h>
	17	#include <linux/unistd.h>
	18	#include <linux/notifier.h>
	19
	20	#include <asm/traps.h>
7c0f6ba6	21	#include <linux/uaccess.h>
5f97f7f9 HS	22	#include <asm/ocd.h>
5f97f7f9 HS	23	#include <asm/mmu_context.h>
1eeb66a1	24	#include <linux/kdebug.h>
5f97f7f9 HS	25
	26	static struct pt_regs get_user_regs(struct task_struct tsk)
	27	{
c9f4f06d	28	return (struct pt_regs *)((unsigned long)task_stack_page(tsk) +
5f97f7f9 HS	29	THREAD_SIZE - sizeof(struct pt_regs));
	30	}
	31
9e584fbb	32	void user_enable_single_step(struct task_struct *tsk)
5f97f7f9	33	{
1d839317	34	pr_debug("user_enable_single_step: pid=%u, PC=0x%08lx, SR=0x%08lx\n",
2507bc13	35	tsk->pid, task_pt_regs(tsk)->pc, task_pt_regs(tsk)->sr);
5f97f7f9	36
2507bc13 HS	37	/*
	38	* We can't schedule in Debug mode, so when TIF_BREAKPOINT is
	39	* set, the system call or exception handler will do a
	40	* breakpoint to enter monitor mode before returning to
	41	* userspace.
	42	*
	43	* The monitor code will then notice that TIF_SINGLE_STEP is
	44	* set and return to userspace with single stepping enabled.
	45	* The CPU will then enter monitor mode again after exactly
	46	* one instruction has been executed, and the monitor code
	47	* will then send a SIGTRAP to the process.
	48	*/
	49	set_tsk_thread_flag(tsk, TIF_BREAKPOINT);
5f97f7f9 HS	50	set_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
	51	}
	52
1d839317 CH	53	void user_disable_single_step(struct task_struct *child)
	54	{
	55	/* XXX(hch): a no-op here seems wrong.. */
	56	}
	57
5f97f7f9 HS	58	/*
	59	* Called by kernel/ptrace.c when detaching
	60	*
	61	* Make sure any single step bits, etc. are not set
	62	*/
	63	void ptrace_disable(struct task_struct *child)
	64	{
	65	clear_tsk_thread_flag(child, TIF_SINGLE_STEP);
2507bc13	66	clear_tsk_thread_flag(child, TIF_BREAKPOINT);
13b54a50	67	ocd_disable(child);
5f97f7f9 HS	68	}
	69
	70	/*
	71	* Read the word at offset "offset" into the task's "struct user". We
	72	* actually access the pt_regs struct stored on the kernel stack.
	73	*/
	74	static int ptrace_read_user(struct task_struct *tsk, unsigned long offset,
	75	unsigned long __user *data)
	76	{
	77	unsigned long *regs;
	78	unsigned long value;
	79
5f97f7f9 HS	80	if (offset & 3 \|\| offset >= sizeof(struct user)) {
	81	printk("ptrace_read_user: invalid offset 0x%08lx\n", offset);
	82	return -EIO;
	83	}
	84
	85	regs = (unsigned long *)get_user_regs(tsk);
	86
	87	value = 0;
	88	if (offset < sizeof(struct pt_regs))
	89	value = regs[offset / sizeof(regs[0])];
	90
2507bc13 HS	91	pr_debug("ptrace_read_user(%s[%u], %#lx, %p) -> %#lx\n",
	92	tsk->comm, tsk->pid, offset, data, value);
	93
5f97f7f9 HS	94	return put_user(value, data);
	95	}
	96
	97	/*
	98	* Write the word "value" to offset "offset" into the task's "struct
	99	* user". We actually access the pt_regs struct stored on the kernel
	100	* stack.
	101	*/
	102	static int ptrace_write_user(struct task_struct *tsk, unsigned long offset,
	103	unsigned long value)
	104	{
	105	unsigned long *regs;
	106
2507bc13 HS	107	pr_debug("ptrace_write_user(%s[%u], %#lx, %#lx)\n",
	108	tsk->comm, tsk->pid, offset, value);
	109
5f97f7f9	110	if (offset & 3 \|\| offset >= sizeof(struct user)) {
2507bc13	111	pr_debug(" invalid offset 0x%08lx\n", offset);
5f97f7f9 HS	112	return -EIO;
	113	}
	114
	115	if (offset >= sizeof(struct pt_regs))
	116	return 0;
	117
	118	regs = (unsigned long *)get_user_regs(tsk);
	119	regs[offset / sizeof(regs[0])] = value;
	120
	121	return 0;
	122	}
	123
	124	static int ptrace_getregs(struct task_struct tsk, void __user uregs)
	125	{
	126	struct pt_regs *regs = get_user_regs(tsk);
	127
	128	return copy_to_user(uregs, regs, sizeof(*regs)) ? -EFAULT : 0;
	129	}
	130
	131	static int ptrace_setregs(struct task_struct tsk, const void __user uregs)
	132	{
	133	struct pt_regs newregs;
	134	int ret;
	135
	136	ret = -EFAULT;
	137	if (copy_from_user(&newregs, uregs, sizeof(newregs)) == 0) {
	138	struct pt_regs *regs = get_user_regs(tsk);
	139
	140	ret = -EINVAL;
	141	if (valid_user_regs(&newregs)) {
	142	*regs = newregs;
	143	ret = 0;
	144	}
	145	}
	146
	147	return ret;
	148	}
	149
9b05a69e NK	150	long arch_ptrace(struct task_struct *child, long request,
9b05a69e NK	151	unsigned long addr, unsigned long data)
5f97f7f9	152	{
5f97f7f9	153	int ret;
9f29b8fb	154	void __user datap = (void __user ) data;
5f97f7f9	155
5f97f7f9 HS	156	switch (request) {
	157	/* Read the word at location addr in the child process */
	158	case PTRACE_PEEKTEXT:
	159	case PTRACE_PEEKDATA:
76647323	160	ret = generic_ptrace_peekdata(child, addr, data);
5f97f7f9 HS	161	break;
	162
	163	case PTRACE_PEEKUSR:
9f29b8fb	164	ret = ptrace_read_user(child, addr, datap);
5f97f7f9 HS	165	break;
	166
	167	/* Write the word in data at location addr */
	168	case PTRACE_POKETEXT:
	169	case PTRACE_POKEDATA:
f284ce72	170	ret = generic_ptrace_pokedata(child, addr, data);
5f97f7f9 HS	171	break;
	172
	173	case PTRACE_POKEUSR:
	174	ret = ptrace_write_user(child, addr, data);
	175	break;
	176
5f97f7f9	177	case PTRACE_GETREGS:
9f29b8fb	178	ret = ptrace_getregs(child, datap);
5f97f7f9 HS	179	break;
	180
	181	case PTRACE_SETREGS:
9f29b8fb	182	ret = ptrace_setregs(child, datap);
5f97f7f9 HS	183	break;
	184
	185	default:
	186	ret = ptrace_request(child, request, addr, data);
	187	break;
	188	}
	189
5f97f7f9 HS	190	return ret;
	191	}
	192
	193	asmlinkage void syscall_trace(void)
	194	{
5f97f7f9 HS	195	if (!test_thread_flag(TIF_SYSCALL_TRACE))
	196	return;
	197	if (!(current->ptrace & PT_PTRACED))
	198	return;
	199
5f97f7f9 HS	200	/* The 0x80 provides a way for the tracing parent to
	201	* distinguish between a syscall stop and SIGTRAP delivery */
	202	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	203	? 0x80 : 0));
	204
	205	/*
	206	* this isn't the same as continuing with a signal, but it
	207	* will do for normal use. strace only continues with a
	208	* signal if the stopping signal is not SIGTRAP. -brl
	209	*/
	210	if (current->exit_code) {
	211	pr_debug("syscall_trace: sending signal %d to PID %u\n",
	212	current->exit_code, current->pid);
	213	send_sig(current->exit_code, current, 1);
	214	current->exit_code = 0;
	215	}
	216	}
	217
5f97f7f9	218	/*
2507bc13 HS	219	* debug_trampoline() is an assembly stub which will store all user
	220	* registers on the stack and execute a breakpoint instruction.
	221	*
	222	* If we single-step into an exception handler which runs with
	223	* interrupts disabled the whole time so it doesn't have to check for
	224	* pending work, its return address will be modified so that it ends
	225	* up returning to debug_trampoline.
	226	*
	227	* If the exception handler decides to store the user context and
	228	* enable interrupts after all, it will restore the original return
	229	* address and status register value. Before it returns, it will
	230	* notice that TIF_BREAKPOINT is set and execute a breakpoint
	231	* instruction.
5f97f7f9	232	*/
2507bc13	233	extern void debug_trampoline(void);
5f97f7f9	234
2507bc13 HS	235	asmlinkage struct pt_regs do_debug(struct pt_regs regs)
	236	{
	237	struct thread_info *ti;
	238	unsigned long trampoline_addr;
	239	u32 status;
	240	u32 ctrl;
	241	int code;
	242
	243	status = ocd_read(DS);
	244	ti = current_thread_info();
	245	code = TRAP_BRKPT;
	246
	247	pr_debug("do_debug: status=0x%08x PC=0x%08lx SR=0x%08lx tif=0x%08lx\n",
	248	status, regs->pc, regs->sr, ti->flags);
	249
	250	if (!user_mode(regs)) {
	251	unsigned long die_val = DIE_BREAKPOINT;
	252
	253	if (status & (1 << OCD_DS_SSS_BIT))
	254	die_val = DIE_SSTEP;
	255
	256	if (notify_die(die_val, "ptrace", regs, 0, 0, SIGTRAP)
	257	== NOTIFY_STOP)
	258	return regs;
	259
	260	if ((status & (1 << OCD_DS_SWB_BIT))
	261	&& test_and_clear_ti_thread_flag(
	262	ti, TIF_BREAKPOINT)) {
	263	/*
	264	* Explicit breakpoint from trampoline or
	265	* exception/syscall/interrupt handler.
	266	*
	267	* The real saved regs are on the stack right
	268	* after the ones we saved on entry.
	269	*/
	270	regs++;
	271	pr_debug(" -> TIF_BREAKPOINT done, adjusted regs:"
	272	"PC=0x%08lx SR=0x%08lx\n",
	273	regs->pc, regs->sr);
	274	BUG_ON(!user_mode(regs));
	275
	276	if (test_thread_flag(TIF_SINGLE_STEP)) {
	277	pr_debug("Going to do single step...\n");
	278	return regs;
	279	}
	280
	281	/*
	282	* No TIF_SINGLE_STEP means we're done
	283	* stepping over a syscall. Do the trap now.
	284	*/
	285	code = TRAP_TRACE;
	286	} else if ((status & (1 << OCD_DS_SSS_BIT))
	287	&& test_ti_thread_flag(ti, TIF_SINGLE_STEP)) {
	288
	289	pr_debug("Stepped into something, "
	290	"setting TIF_BREAKPOINT...\n");
	291	set_ti_thread_flag(ti, TIF_BREAKPOINT);
	292
	293	/*
	294	* We stepped into an exception, interrupt or
	295	* syscall handler. Some exception handlers
	296	* don't check for pending work, so we need to
	297	* set up a trampoline just in case.
	298	*
299	* The exception entry code will undo the
300	* trampoline stuff if it does a full context
301	* save (which also means that it'll check for
302	* pending work later.)
303	*/
304	if ((regs->sr & MODE_MASK) == MODE_EXCEPTION) {
305	trampoline_addr
306	= (unsigned long)&debug_trampoline;
307
308	pr_debug("Setting up trampoline...\n");
309	ti->rar_saved = sysreg_read(RAR_EX);
310	ti->rsr_saved = sysreg_read(RSR_EX);
311	sysreg_write(RAR_EX, trampoline_addr);
312	sysreg_write(RSR_EX, (MODE_EXCEPTION
313	\| SR_EM \| SR_GM));
314	BUG_ON(ti->rsr_saved & MODE_MASK);
315	}
316
317	/*
318	* If we stepped into a system call, we
319	* shouldn't do a single step after we return
320	* since the return address is right after the
321	* "scall" instruction we were told to step
322	* over.
323	*/
324	if ((regs->sr & MODE_MASK) == MODE_SUPERVISOR) {
325	pr_debug("Supervisor; no single step\n");
326	clear_ti_thread_flag(ti, TIF_SINGLE_STEP);
327	}
328
329	ctrl = ocd_read(DC);
330	ctrl &= ~(1 << OCD_DC_SS_BIT);
331	ocd_write(DC, ctrl);
332
333	return regs;
334	} else {
335	printk(KERN_ERR "Unexpected OCD_DS value: 0x%08x\n",
336	status);
337	printk(KERN_ERR "Thread flags: 0x%08lx\n", ti->flags);
338	die("Unhandled debug trap in kernel mode",
339	regs, SIGTRAP);
340	}
341	} else if (status & (1 << OCD_DS_SSS_BIT)) {
342	/* Single step in user mode */
343	code = TRAP_TRACE;
5f97f7f9	344
2507bc13 HS	345	ctrl = ocd_read(DC);
	346	ctrl &= ~(1 << OCD_DC_SS_BIT);
	347	ocd_write(DC, ctrl);
5f97f7f9 HS	348	}
5f97f7f9 HS	349
2507bc13 HS	350	pr_debug("Sending SIGTRAP: code=%d PC=0x%08lx SR=0x%08lx\n",
2507bc13 HS	351	code, regs->pc, regs->sr);
5f97f7f9	352
2507bc13 HS	353	clear_thread_flag(TIF_SINGLE_STEP);
	354	_exception(SIGTRAP, regs, code, instruction_pointer(regs));
	355
	356	return regs;
5f97f7f9	357	}