[net-next-2.6.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/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 <asm/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));
}

static void ptrace_single_step(struct task_struct *tsk)
{
	pr_debug("ptrace_single_step: pid=%u, SR=0x%08lx\n",
		 tsk->pid, tsk->thread.cpu_context.sr);
	if (!(tsk->thread.cpu_context.sr & SR_D)) {
		/*
		 * Set a breakpoint at the current pc to force the
		 * process into debug mode.  The syscall/exception
		 * exit code will set a breakpoint at the return
		 * address when this flag is set.
		 */
		pr_debug("ptrace_single_step: Setting TIF_BREAKPOINT\n");
		set_tsk_thread_flag(tsk, TIF_BREAKPOINT);
	}

	/* The monitor code will do the actual step for us */
	set_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
}

/*
 * 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);
}

/*
 * Handle hitting a breakpoint
 */
static void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
{
	siginfo_t info;

	info.si_signo = SIGTRAP;
	info.si_errno = 0;
	info.si_code  = TRAP_BRKPT;
	info.si_addr  = (void __user *)instruction_pointer(regs);

	pr_debug("ptrace_break: Sending SIGTRAP to PID %u (pc = 0x%p)\n",
		 tsk->pid, info.si_addr);
	force_sig_info(SIGTRAP, &info, tsk);
}

/*
 * 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;

	pr_debug("ptrace_read_user(%p, %#lx, %p)\n",
		 tsk, offset, data);

	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])];

	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;

	if (offset & 3 || offset >= sizeof(struct user)) {
		printk("ptrace_write_user: 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, long addr, long data)
{
	int ret;

	pr_debug("arch_ptrace(%ld, %d, %#lx, %#lx)\n",
		 request, child->pid, addr, data);

	pr_debug("ptrace: Enabling monitor mode...\n");
	__mtdr(DBGREG_DC, __mfdr(DBGREG_DC) | DC_MM | DC_DBE);

	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,
				       (unsigned long __user *)data);
		break;

	/* Write the word in data at location addr */
	case PTRACE_POKETEXT:
	case PTRACE_POKEDATA:
		ret = access_process_vm(child, addr, &data, sizeof(data), 1);
		if (ret == sizeof(data))
			ret = 0;
		else
			ret = -EIO;
		break;

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

	/* continue and stop at next (return from) syscall */
	case PTRACE_SYSCALL:
	/* restart after signal */
	case PTRACE_CONT:
		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;
		/* XXX: Are we sure no breakpoints are active here? */
		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;
		wake_up_process(child);
		break;

	/*
	 * execute single instruction.
	 */
	case PTRACE_SINGLESTEP:
		ret = -EIO;
		if (!valid_signal(data))
			break;
		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		ptrace_single_step(child);
		child->exit_code = data;
		wake_up_process(child);
		ret = 0;
		break;

	/* Detach a process that was attached */
	case PTRACE_DETACH:
		ret = ptrace_detach(child, data);
		break;

	case PTRACE_GETREGS:
		ret = ptrace_getregs(child, (void __user *)data);
		break;

	case PTRACE_SETREGS:
		ret = ptrace_setregs(child, (const void __user *)data);
		break;

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

	pr_debug("sys_ptrace returning %d (DC = 0x%08lx)\n", ret, __mfdr(DBGREG_DC));
	return ret;
}

asmlinkage void syscall_trace(void)
{
	pr_debug("syscall_trace called\n");
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;
	if (!(current->ptrace & PT_PTRACED))
		return;

	pr_debug("syscall_trace: notifying parent\n");
	/* 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;
	}
}

asmlinkage void do_debug_priv(struct pt_regs *regs)
{
	unsigned long dc, ds;
	unsigned long die_val;

	ds = __mfdr(DBGREG_DS);

	pr_debug("do_debug_priv: pc = %08lx, ds = %08lx\n", regs->pc, ds);

	if (ds & DS_SSS)
		die_val = DIE_SSTEP;
	else
		die_val = DIE_BREAKPOINT;

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

	if (likely(ds & DS_SSS)) {
		extern void itlb_miss(void);
		extern void tlb_miss_common(void);
		struct thread_info *ti;

		dc = __mfdr(DBGREG_DC);
		dc &= ~DC_SS;
		__mtdr(DBGREG_DC, dc);

		ti = current_thread_info();
		set_ti_thread_flag(ti, TIF_BREAKPOINT);

		/* The TLB miss handlers don't check thread flags */
		if ((regs->pc >= (unsigned long)&itlb_miss)
		    && (regs->pc <= (unsigned long)&tlb_miss_common)) {
			__mtdr(DBGREG_BWA2A, sysreg_read(RAR_EX));
			__mtdr(DBGREG_BWC2A, 0x40000001 | (get_asid() << 1));
		}

		/*
		 * If we're running in supervisor mode, the breakpoint
		 * will take us where we want directly, no need to
		 * single step.
		 */
		if ((regs->sr & MODE_MASK) != MODE_SUPERVISOR)
			set_ti_thread_flag(ti, TIF_SINGLE_STEP);
	} else {
		panic("Unable to handle debug trap at pc = %08lx\n",
		      regs->pc);
	}
}

/*
 * Handle breakpoints, single steps and other debuggy things. To keep
 * things simple initially, we run with interrupts and exceptions
 * disabled all the time.
 */
asmlinkage void do_debug(struct pt_regs *regs)
{
	unsigned long dc, ds;

	ds = __mfdr(DBGREG_DS);
	pr_debug("do_debug: pc = %08lx, ds = %08lx\n", regs->pc, ds);

	if (test_thread_flag(TIF_BREAKPOINT)) {
		pr_debug("TIF_BREAKPOINT set\n");
		/* We're taking care of it */
		clear_thread_flag(TIF_BREAKPOINT);
		__mtdr(DBGREG_BWC2A, 0);
	}

	if (test_thread_flag(TIF_SINGLE_STEP)) {
		pr_debug("TIF_SINGLE_STEP set, ds = 0x%08lx\n", ds);
		if (ds & DS_SSS) {
			dc = __mfdr(DBGREG_DC);
			dc &= ~DC_SS;
			__mtdr(DBGREG_DC, dc);

			clear_thread_flag(TIF_SINGLE_STEP);
			ptrace_break(current, regs);
		}
	} else {
		/* regular breakpoint */
		ptrace_break(current, 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>
	11	#include <linux/mm.h>
5f97f7f9 HS	12	#include <linux/ptrace.h>
	13	#include <linux/errno.h>
	14	#include <linux/user.h>
	15	#include <linux/security.h>
	16	#include <linux/unistd.h>
	17	#include <linux/notifier.h>
	18
	19	#include <asm/traps.h>
	20	#include <asm/uaccess.h>
	21	#include <asm/ocd.h>
	22	#include <asm/mmu_context.h>
1eeb66a1	23	#include <linux/kdebug.h>
5f97f7f9 HS	24
	25	static struct pt_regs get_user_regs(struct task_struct tsk)
	26	{
c9f4f06d	27	return (struct pt_regs *)((unsigned long)task_stack_page(tsk) +
5f97f7f9 HS	28	THREAD_SIZE - sizeof(struct pt_regs));
	29	}
	30
	31	static void ptrace_single_step(struct task_struct *tsk)
	32	{
	33	pr_debug("ptrace_single_step: pid=%u, SR=0x%08lx\n",
	34	tsk->pid, tsk->thread.cpu_context.sr);
	35	if (!(tsk->thread.cpu_context.sr & SR_D)) {
	36	/*
	37	* Set a breakpoint at the current pc to force the
	38	* process into debug mode. The syscall/exception
	39	* exit code will set a breakpoint at the return
	40	* address when this flag is set.
	41	*/
	42	pr_debug("ptrace_single_step: Setting TIF_BREAKPOINT\n");
	43	set_tsk_thread_flag(tsk, TIF_BREAKPOINT);
	44	}
	45
	46	/* The monitor code will do the actual step for us */
	47	set_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
	48	}
	49
	50	/*
	51	* Called by kernel/ptrace.c when detaching
	52	*
	53	* Make sure any single step bits, etc. are not set
	54	*/
	55	void ptrace_disable(struct task_struct *child)
	56	{
	57	clear_tsk_thread_flag(child, TIF_SINGLE_STEP);
	58	}
	59
	60	/*
	61	* Handle hitting a breakpoint
	62	*/
	63	static void ptrace_break(struct task_struct tsk, struct pt_regs regs)
	64	{
	65	siginfo_t info;
	66
	67	info.si_signo = SIGTRAP;
	68	info.si_errno = 0;
	69	info.si_code = TRAP_BRKPT;
	70	info.si_addr = (void __user *)instruction_pointer(regs);
	71
	72	pr_debug("ptrace_break: Sending SIGTRAP to PID %u (pc = 0x%p)\n",
	73	tsk->pid, info.si_addr);
	74	force_sig_info(SIGTRAP, &info, tsk);
	75	}
	76
	77	/*
	78	* Read the word at offset "offset" into the task's "struct user". We
	79	* actually access the pt_regs struct stored on the kernel stack.
	80	*/
	81	static int ptrace_read_user(struct task_struct *tsk, unsigned long offset,
	82	unsigned long __user *data)
	83	{
	84	unsigned long *regs;
	85	unsigned long value;
	86
	87	pr_debug("ptrace_read_user(%p, %#lx, %p)\n",
	88	tsk, offset, data);
	89
	90	if (offset & 3 \|\| offset >= sizeof(struct user)) {
	91	printk("ptrace_read_user: invalid offset 0x%08lx\n", offset);
92	return -EIO;
93	}
94
95	regs = (unsigned long *)get_user_regs(tsk);
96
97	value = 0;
98	if (offset < sizeof(struct pt_regs))
99	value = regs[offset / sizeof(regs[0])];
100
101	return put_user(value, data);
102	}
103
104	/*
105	* Write the word "value" to offset "offset" into the task's "struct
106	* user". We actually access the pt_regs struct stored on the kernel
107	* stack.
108	*/
109	static int ptrace_write_user(struct task_struct *tsk, unsigned long offset,
110	unsigned long value)
111	{
112	unsigned long *regs;
113
114	if (offset & 3 \|\| offset >= sizeof(struct user)) {
115	printk("ptrace_write_user: invalid offset 0x%08lx\n", offset);
116	return -EIO;
117	}
118
119	if (offset >= sizeof(struct pt_regs))
120	return 0;
121
122	regs = (unsigned long *)get_user_regs(tsk);
123	regs[offset / sizeof(regs[0])] = value;
124
125	return 0;
126	}
127
128	static int ptrace_getregs(struct task_struct tsk, void __user uregs)
129	{
130	struct pt_regs *regs = get_user_regs(tsk);
131
132	return copy_to_user(uregs, regs, sizeof(*regs)) ? -EFAULT : 0;
133	}
134
135	static int ptrace_setregs(struct task_struct tsk, const void __user uregs)
136	{
137	struct pt_regs newregs;
138	int ret;
139
140	ret = -EFAULT;
141	if (copy_from_user(&newregs, uregs, sizeof(newregs)) == 0) {
142	struct pt_regs *regs = get_user_regs(tsk);
143
144	ret = -EINVAL;
145	if (valid_user_regs(&newregs)) {
146	*regs = newregs;
147	ret = 0;
148	}
149	}
150
151	return ret;
152	}
153
154	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
155	{
5f97f7f9 HS	156	int ret;
5f97f7f9 HS	157
6ea850b5	158	pr_debug("arch_ptrace(%ld, %d, %#lx, %#lx)\n",
5f97f7f9 HS	159	request, child->pid, addr, data);
	160
	161	pr_debug("ptrace: Enabling monitor mode...\n");
	162	__mtdr(DBGREG_DC, __mfdr(DBGREG_DC) \| DC_MM \| DC_DBE);
	163
	164	switch (request) {
	165	/* Read the word at location addr in the child process */
	166	case PTRACE_PEEKTEXT:
	167	case PTRACE_PEEKDATA:
76647323	168	ret = generic_ptrace_peekdata(child, addr, data);
5f97f7f9 HS	169	break;
	170
	171	case PTRACE_PEEKUSR:
	172	ret = ptrace_read_user(child, addr,
	173	(unsigned long __user *)data);
	174	break;
	175
	176	/* Write the word in data at location addr */
	177	case PTRACE_POKETEXT:
	178	case PTRACE_POKEDATA:
	179	ret = access_process_vm(child, addr, &data, sizeof(data), 1);
	180	if (ret == sizeof(data))
	181	ret = 0;
	182	else
	183	ret = -EIO;
	184	break;
	185
	186	case PTRACE_POKEUSR:
	187	ret = ptrace_write_user(child, addr, data);
	188	break;
	189
	190	/* continue and stop at next (return from) syscall */
	191	case PTRACE_SYSCALL:
	192	/* restart after signal */
	193	case PTRACE_CONT:
	194	ret = -EIO;
	195	if (!valid_signal(data))
	196	break;
	197	if (request == PTRACE_SYSCALL)
	198	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	199	else
	200	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	201	child->exit_code = data;
	202	/* XXX: Are we sure no breakpoints are active here? */
	203	wake_up_process(child);
	204	ret = 0;
	205	break;
	206
	207	/*
	208	* Make the child exit. Best I can do is send it a
	209	* SIGKILL. Perhaps it should be put in the status that it
	210	* wants to exit.
	211	*/
	212	case PTRACE_KILL:
	213	ret = 0;
	214	if (child->exit_state == EXIT_ZOMBIE)
	215	break;
	216	child->exit_code = SIGKILL;
	217	wake_up_process(child);
	218	break;
	219
	220	/*
	221	* execute single instruction.
	222	*/
	223	case PTRACE_SINGLESTEP:
	224	ret = -EIO;
	225	if (!valid_signal(data))
	226	break;
	227	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	228	ptrace_single_step(child);
	229	child->exit_code = data;
	230	wake_up_process(child);
	231	ret = 0;
	232	break;
233
234	/* Detach a process that was attached */
235	case PTRACE_DETACH:
236	ret = ptrace_detach(child, data);
237	break;
238
239	case PTRACE_GETREGS:
240	ret = ptrace_getregs(child, (void __user *)data);
241	break;
242
243	case PTRACE_SETREGS:
244	ret = ptrace_setregs(child, (const void __user *)data);
245	break;
246
247	default:
248	ret = ptrace_request(child, request, addr, data);
249	break;
250	}
251
252	pr_debug("sys_ptrace returning %d (DC = 0x%08lx)\n", ret, __mfdr(DBGREG_DC));
253	return ret;
254	}
255
256	asmlinkage void syscall_trace(void)
257	{
258	pr_debug("syscall_trace called\n");
259	if (!test_thread_flag(TIF_SYSCALL_TRACE))
260	return;
261	if (!(current->ptrace & PT_PTRACED))
262	return;
263
264	pr_debug("syscall_trace: notifying parent\n");
265	/* The 0x80 provides a way for the tracing parent to
266	* distinguish between a syscall stop and SIGTRAP delivery */
267	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
268	? 0x80 : 0));
269
270	/*
271	* this isn't the same as continuing with a signal, but it
272	* will do for normal use. strace only continues with a
273	* signal if the stopping signal is not SIGTRAP. -brl
274	*/
275	if (current->exit_code) {
276	pr_debug("syscall_trace: sending signal %d to PID %u\n",
277	current->exit_code, current->pid);
278	send_sig(current->exit_code, current, 1);
279	current->exit_code = 0;
280	}
281	}
282
283	asmlinkage void do_debug_priv(struct pt_regs *regs)
284	{
285	unsigned long dc, ds;
286	unsigned long die_val;
287
288	ds = __mfdr(DBGREG_DS);
289
290	pr_debug("do_debug_priv: pc = %08lx, ds = %08lx\n", regs->pc, ds);
291
292	if (ds & DS_SSS)
293	die_val = DIE_SSTEP;
294	else
295	die_val = DIE_BREAKPOINT;
296
1eeb66a1	297	if (notify_die(die_val, "ptrace", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
5f97f7f9 HS	298	return;
	299
	300	if (likely(ds & DS_SSS)) {
	301	extern void itlb_miss(void);
	302	extern void tlb_miss_common(void);
	303	struct thread_info *ti;
	304
	305	dc = __mfdr(DBGREG_DC);
	306	dc &= ~DC_SS;
	307	__mtdr(DBGREG_DC, dc);
	308
	309	ti = current_thread_info();
a19b4a14	310	set_ti_thread_flag(ti, TIF_BREAKPOINT);
5f97f7f9 HS	311
	312	/* The TLB miss handlers don't check thread flags */
	313	if ((regs->pc >= (unsigned long)&itlb_miss)
	314	&& (regs->pc <= (unsigned long)&tlb_miss_common)) {
	315	__mtdr(DBGREG_BWA2A, sysreg_read(RAR_EX));
	316	__mtdr(DBGREG_BWC2A, 0x40000001 \| (get_asid() << 1));
	317	}
	318
	319	/*
	320	* If we're running in supervisor mode, the breakpoint
	321	* will take us where we want directly, no need to
	322	* single step.
	323	*/
	324	if ((regs->sr & MODE_MASK) != MODE_SUPERVISOR)
a19b4a14	325	set_ti_thread_flag(ti, TIF_SINGLE_STEP);
5f97f7f9 HS	326	} else {
	327	panic("Unable to handle debug trap at pc = %08lx\n",
	328	regs->pc);
	329	}
	330	}
	331
	332	/*
	333	* Handle breakpoints, single steps and other debuggy things. To keep
	334	* things simple initially, we run with interrupts and exceptions
	335	* disabled all the time.
	336	*/
	337	asmlinkage void do_debug(struct pt_regs *regs)
	338	{
	339	unsigned long dc, ds;
	340
	341	ds = __mfdr(DBGREG_DS);
	342	pr_debug("do_debug: pc = %08lx, ds = %08lx\n", regs->pc, ds);
	343
	344	if (test_thread_flag(TIF_BREAKPOINT)) {
	345	pr_debug("TIF_BREAKPOINT set\n");
	346	/* We're taking care of it */
	347	clear_thread_flag(TIF_BREAKPOINT);
	348	__mtdr(DBGREG_BWC2A, 0);
	349	}
	350
	351	if (test_thread_flag(TIF_SINGLE_STEP)) {
	352	pr_debug("TIF_SINGLE_STEP set, ds = 0x%08lx\n", ds);
	353	if (ds & DS_SSS) {
	354	dc = __mfdr(DBGREG_DC);
	355	dc &= ~DC_SS;
	356	__mtdr(DBGREG_DC, dc);
	357
	358	clear_thread_flag(TIF_SINGLE_STEP);
	359	ptrace_break(current, regs);
	360	}
	361	} else {
	362	/* regular breakpoint */
	363	ptrace_break(current, regs);
	364	}
	365	}