[deliverable/linux.git] / arch / mips / kernel / ptrace.c

/*
 * 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.
 *
 * Copyright (C) 1992 Ross Biro
 * Copyright (C) Linus Torvalds
 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
 * Copyright (C) 1996 David S. Miller
 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999 MIPS Technologies, Inc.
 * Copyright (C) 2000 Ulf Carlsson
 *
 * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
 * binaries.
 */
#include <linux/config.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/audit.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>

#include <asm/byteorder.h>
#include <asm/cpu.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/bootinfo.h>

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	/* Nothing to do.. */
}

asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
	struct task_struct *child;
	int ret;

#if 0
	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
	       (int) request, (int) pid, (unsigned long) addr,
	       (unsigned long) data);
#endif
	lock_kernel();
	ret = -EPERM;
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		if ((ret = security_ptrace(current->parent, current)))
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}
	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;

	ret = -EPERM;
	if (pid == 1)		/* you may not mess with init */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		ret = ptrace_attach(child);
		goto out_tsk;
	}

	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	if (ret < 0)
		goto out_tsk;

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKTEXT: /* read word at location addr. */
	case PTRACE_PEEKDATA: {
		unsigned long tmp;
		int copied;

		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
		ret = -EIO;
		if (copied != sizeof(tmp))
			break;
		ret = put_user(tmp,(unsigned long __user *) data);
		break;
	}

	/* Read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		struct pt_regs *regs;
		unsigned long tmp = 0;

		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
		ret = 0;  /* Default return value. */

		switch (addr) {
		case 0 ... 31:
			tmp = regs->regs[addr];
			break;
		case FPR_BASE ... FPR_BASE + 31:
			if (tsk_used_math(child)) {
				fpureg_t *fregs = get_fpu_regs(child);

#ifdef CONFIG_32BIT
				/*
				 * The odd registers are actually the high
				 * order bits of the values stored in the even
				 * registers - unless we're using r2k_switch.S.
				 */
				if (addr & 1)
					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
				else
					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
#endif
#ifdef CONFIG_64BIT
				tmp = fregs[addr - FPR_BASE];
#endif
			} else {
				tmp = -1;	/* FP not yet used  */
			}
			break;
		case PC:
			tmp = regs->cp0_epc;
			break;
		case CAUSE:
			tmp = regs->cp0_cause;
			break;
		case BADVADDR:
			tmp = regs->cp0_badvaddr;
			break;
		case MMHI:
			tmp = regs->hi;
			break;
		case MMLO:
			tmp = regs->lo;
			break;
		case FPC_CSR:
			if (cpu_has_fpu)
				tmp = child->thread.fpu.hard.fcr31;
			else
				tmp = child->thread.fpu.soft.fcr31;
			break;
		case FPC_EIR: {	/* implementation / version register */
			unsigned int flags;

			if (!cpu_has_fpu)
				break;

			flags = read_c0_status();
			__enable_fpu();
			__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
			write_c0_status(flags);
			break;
		}
		default:
			tmp = 0;
			ret = -EIO;
			goto out_tsk;
		}
		ret = put_user(tmp, (unsigned long __user *) data);
		break;
	}

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA:
		ret = 0;
		if (access_process_vm(child, addr, &data, sizeof(data), 1)
		    == sizeof(data))
			break;
		ret = -EIO;
		break;

	case PTRACE_POKEUSR: {
		struct pt_regs *regs;
		ret = 0;
		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
		       THREAD_SIZE - 32 - sizeof(struct pt_regs));

		switch (addr) {
		case 0 ... 31:
			regs->regs[addr] = data;
			break;
		case FPR_BASE ... FPR_BASE + 31: {
			fpureg_t *fregs = get_fpu_regs(child);

			if (!tsk_used_math(child)) {
				/* FP not yet used  */
				memset(&child->thread.fpu.hard, ~0,
				       sizeof(child->thread.fpu.hard));
				child->thread.fpu.hard.fcr31 = 0;
			}
#ifdef CONFIG_32BIT
			/*
			 * The odd registers are actually the high order bits
			 * of the values stored in the even registers - unless
			 * we're using r2k_switch.S.
			 */
			if (addr & 1) {
				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
			} else {
				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
				fregs[addr - FPR_BASE] |= data;
			}
#endif
#ifdef CONFIG_64BIT
			fregs[addr - FPR_BASE] = data;
#endif
			break;
		}
		case PC:
			regs->cp0_epc = data;
			break;
		case MMHI:
			regs->hi = data;
			break;
		case MMLO:
			regs->lo = data;
			break;
		case FPC_CSR:
			if (cpu_has_fpu)
				child->thread.fpu.hard.fcr31 = data;
			else
				child->thread.fpu.soft.fcr31 = data;
			break;
		default:
			/* The rest are not allowed. */
			ret = -EIO;
			break;
		}
		break;
		}

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT: { /* restart after signal. */
		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;
		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)	/* already dead */
			break;
		child->exit_code = SIGKILL;
		wake_up_process(child);
		break;

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

	case PTRACE_GET_THREAD_AREA:
		ret = put_user(child->thread_info->tp_value,
				(unsigned long __user *) data);
		break;

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

out_tsk:
	put_task_struct(child);
out:
	unlock_kernel();
	return ret;
}

static inline int audit_arch(void)
{
	int arch = EM_MIPS;
#ifdef CONFIG_64BIT
	arch |=  __AUDIT_ARCH_64BIT;
#endif
#if defined(__LITTLE_ENDIAN)
	arch |=  __AUDIT_ARCH_LE;
#endif
	return arch;
}

/*
 * Notification of system call entry/exit
 * - triggered by current->work.syscall_trace
 */
asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
{
	if (unlikely(current->audit_context) && entryexit)
		audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]),
		                   regs->regs[2]);

	if (!(current->ptrace & PT_PTRACED))
		goto out;
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		goto out;

	/* 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) {
		send_sig(current->exit_code, current, 1);
		current->exit_code = 0;
	}
 out:
	if (unlikely(current->audit_context) && !entryexit)
		audit_syscall_entry(current, audit_arch(), regs->regs[2],
				    regs->regs[4], regs->regs[5],
				    regs->regs[6], regs->regs[7]);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1992 Ross Biro
	7	* Copyright (C) Linus Torvalds
	8	* Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
	9	* Copyright (C) 1996 David S. Miller
	10	* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
	11	* Copyright (C) 1999 MIPS Technologies, Inc.
	12	* Copyright (C) 2000 Ulf Carlsson
	13	*
	14	* At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
	15	* binaries.
	16	*/
	17	#include <linux/config.h>
	18	#include <linux/compiler.h>
	19	#include <linux/kernel.h>
	20	#include <linux/sched.h>
	21	#include <linux/mm.h>
	22	#include <linux/errno.h>
	23	#include <linux/ptrace.h>
	24	#include <linux/audit.h>
	25	#include <linux/smp.h>
	26	#include <linux/smp_lock.h>
	27	#include <linux/user.h>
	28	#include <linux/security.h>
7ed20e1a	29	#include <linux/signal.h>
1da177e4	30
f8280c8d	31	#include <asm/byteorder.h>
1da177e4 LT	32	#include <asm/cpu.h>
	33	#include <asm/fpu.h>
	34	#include <asm/mipsregs.h>
	35	#include <asm/pgtable.h>
	36	#include <asm/page.h>
	37	#include <asm/system.h>
	38	#include <asm/uaccess.h>
	39	#include <asm/bootinfo.h>
	40
	41	/*
	42	* Called by kernel/ptrace.c when detaching..
	43	*
	44	* Make sure single step bits etc are not set.
	45	*/
	46	void ptrace_disable(struct task_struct *child)
	47	{
	48	/* Nothing to do.. */
	49	}
	50
	51	asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
	52	{
	53	struct task_struct *child;
	54	int ret;
	55
	56	#if 0
	57	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
	58	(int) request, (int) pid, (unsigned long) addr,
	59	(unsigned long) data);
	60	#endif
	61	lock_kernel();
	62	ret = -EPERM;
	63	if (request == PTRACE_TRACEME) {
	64	/* are we already being traced? */
	65	if (current->ptrace & PT_PTRACED)
	66	goto out;
	67	if ((ret = security_ptrace(current->parent, current)))
	68	goto out;
	69	/* set the ptrace bit in the process flags. */
	70	current->ptrace \|= PT_PTRACED;
	71	ret = 0;
	72	goto out;
	73	}
	74	ret = -ESRCH;
	75	read_lock(&tasklist_lock);
	76	child = find_task_by_pid(pid);
	77	if (child)
	78	get_task_struct(child);
	79	read_unlock(&tasklist_lock);
	80	if (!child)
	81	goto out;
	82
	83	ret = -EPERM;
	84	if (pid == 1) /* you may not mess with init */
	85	goto out_tsk;
	86
	87	if (request == PTRACE_ATTACH) {
	88	ret = ptrace_attach(child);
	89	goto out_tsk;
	90	}
	91
	92	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	93	if (ret < 0)
	94	goto out_tsk;
	95
96	switch (request) {
97	/* when I and D space are separate, these will need to be fixed. */
98	case PTRACE_PEEKTEXT: /* read word at location addr. */
99	case PTRACE_PEEKDATA: {
100	unsigned long tmp;
101	int copied;
102
103	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
104	ret = -EIO;
105	if (copied != sizeof(tmp))
106	break;
fe00f943	107	ret = put_user(tmp,(unsigned long __user *) data);
1da177e4 LT	108	break;
	109	}
	110
	111	/* Read the word at location addr in the USER area. */
	112	case PTRACE_PEEKUSR: {
	113	struct pt_regs *regs;
	114	unsigned long tmp = 0;
	115
	116	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
	117	THREAD_SIZE - 32 - sizeof(struct pt_regs));
	118	ret = 0; /* Default return value. */
	119
	120	switch (addr) {
	121	case 0 ... 31:
	122	tmp = regs->regs[addr];
	123	break;
	124	case FPR_BASE ... FPR_BASE + 31:
	125	if (tsk_used_math(child)) {
	126	fpureg_t *fregs = get_fpu_regs(child);
	127
875d43e7	128	#ifdef CONFIG_32BIT
1da177e4 LT	129	/*
	130	* The odd registers are actually the high
	131	* order bits of the values stored in the even
	132	* registers - unless we're using r2k_switch.S.
	133	*/
	134	if (addr & 1)
	135	tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
	136	else
	137	tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
	138	#endif
875d43e7	139	#ifdef CONFIG_64BIT
1da177e4 LT	140	tmp = fregs[addr - FPR_BASE];
	141	#endif
	142	} else {
	143	tmp = -1; /* FP not yet used */
	144	}
	145	break;
	146	case PC:
	147	tmp = regs->cp0_epc;
	148	break;
	149	case CAUSE:
	150	tmp = regs->cp0_cause;
	151	break;
	152	case BADVADDR:
	153	tmp = regs->cp0_badvaddr;
	154	break;
	155	case MMHI:
	156	tmp = regs->hi;
	157	break;
	158	case MMLO:
	159	tmp = regs->lo;
	160	break;
	161	case FPC_CSR:
	162	if (cpu_has_fpu)
	163	tmp = child->thread.fpu.hard.fcr31;
	164	else
	165	tmp = child->thread.fpu.soft.fcr31;
	166	break;
	167	case FPC_EIR: { /* implementation / version register */
	168	unsigned int flags;
	169
	170	if (!cpu_has_fpu)
	171	break;
	172
	173	flags = read_c0_status();
	174	__enable_fpu();
	175	__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
	176	write_c0_status(flags);
	177	break;
	178	}
	179	default:
	180	tmp = 0;
	181	ret = -EIO;
	182	goto out_tsk;
	183	}
fe00f943	184	ret = put_user(tmp, (unsigned long __user *) data);
1da177e4 LT	185	break;
	186	}
	187
	188	/* when I and D space are separate, this will have to be fixed. */
	189	case PTRACE_POKETEXT: /* write the word at location addr. */
	190	case PTRACE_POKEDATA:
	191	ret = 0;
	192	if (access_process_vm(child, addr, &data, sizeof(data), 1)
	193	== sizeof(data))
	194	break;
	195	ret = -EIO;
	196	break;
	197
	198	case PTRACE_POKEUSR: {
	199	struct pt_regs *regs;
	200	ret = 0;
	201	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
	202	THREAD_SIZE - 32 - sizeof(struct pt_regs));
	203
	204	switch (addr) {
	205	case 0 ... 31:
	206	regs->regs[addr] = data;
	207	break;
	208	case FPR_BASE ... FPR_BASE + 31: {
	209	fpureg_t *fregs = get_fpu_regs(child);
	210
	211	if (!tsk_used_math(child)) {
	212	/* FP not yet used */
	213	memset(&child->thread.fpu.hard, ~0,
	214	sizeof(child->thread.fpu.hard));
	215	child->thread.fpu.hard.fcr31 = 0;
	216	}
875d43e7	217	#ifdef CONFIG_32BIT
1da177e4 LT	218	/*
	219	* The odd registers are actually the high order bits
	220	* of the values stored in the even registers - unless
	221	* we're using r2k_switch.S.
	222	*/
	223	if (addr & 1) {
	224	fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
	225	fregs[(addr & ~1) - FPR_BASE] \|= ((unsigned long long) data) << 32;
	226	} else {
	227	fregs[addr - FPR_BASE] &= ~0xffffffffLL;
	228	fregs[addr - FPR_BASE] \|= data;
	229	}
	230	#endif
875d43e7	231	#ifdef CONFIG_64BIT
1da177e4 LT	232	fregs[addr - FPR_BASE] = data;
	233	#endif
	234	break;
	235	}
	236	case PC:
	237	regs->cp0_epc = data;
	238	break;
	239	case MMHI:
	240	regs->hi = data;
	241	break;
	242	case MMLO:
	243	regs->lo = data;
	244	break;
	245	case FPC_CSR:
	246	if (cpu_has_fpu)
	247	child->thread.fpu.hard.fcr31 = data;
	248	else
	249	child->thread.fpu.soft.fcr31 = data;
	250	break;
	251	default:
	252	/* The rest are not allowed. */
	253	ret = -EIO;
	254	break;
	255	}
	256	break;
	257	}
	258
	259	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	260	case PTRACE_CONT: { /* restart after signal. */
	261	ret = -EIO;
7ed20e1a	262	if (!valid_signal(data))
1da177e4 LT	263	break;
	264	if (request == PTRACE_SYSCALL) {
	265	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	266	}
	267	else {
	268	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	269	}
	270	child->exit_code = data;
	271	wake_up_process(child);
	272	ret = 0;
	273	break;
	274	}
	275
	276	/*
	277	* make the child exit. Best I can do is send it a sigkill.
	278	* perhaps it should be put in the status that it wants to
	279	* exit.
	280	*/
	281	case PTRACE_KILL:
	282	ret = 0;
	283	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	284	break;
	285	child->exit_code = SIGKILL;
	286	wake_up_process(child);
	287	break;
	288
	289	case PTRACE_DETACH: /* detach a process that was attached. */
	290	ret = ptrace_detach(child, data);
	291	break;
	292
3c37026d RB	293	case PTRACE_GET_THREAD_AREA:
	294	ret = put_user(child->thread_info->tp_value,
	295	(unsigned long __user *) data);
	296	break;
	297
1da177e4 LT	298	default:
	299	ret = ptrace_request(child, request, addr, data);
	300	break;
	301	}
	302
	303	out_tsk:
	304	put_task_struct(child);
	305	out:
	306	unlock_kernel();
	307	return ret;
	308	}
	309
67eb81e1	310	static inline int audit_arch(void)
2fd6f58b	311	{
f8280c8d	312	int arch = EM_MIPS;
875d43e7	313	#ifdef CONFIG_64BIT
f8280c8d RB	314	arch \|= __AUDIT_ARCH_64BIT;
	315	#endif
	316	#if defined(__LITTLE_ENDIAN)
	317	arch \|= __AUDIT_ARCH_LE;
	318	#endif
	319	return arch;
2fd6f58b	320	}
2fd6f58b	321
1da177e4 LT	322	/*
	323	* Notification of system call entry/exit
	324	* - triggered by current->work.syscall_trace
	325	*/
	326	asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
	327	{
2fd6f58b	328	if (unlikely(current->audit_context) && entryexit)
f8280c8d RB	329	audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]),
f8280c8d RB	330	regs->regs[2]);
1da177e4	331
1da177e4	332	if (!(current->ptrace & PT_PTRACED))
2fd6f58b	333	goto out;
f8280c8d RB	334	if (!test_thread_flag(TIF_SYSCALL_TRACE))
f8280c8d RB	335	goto out;
1da177e4 LT	336
	337	/* The 0x80 provides a way for the tracing parent to distinguish
	338	between a syscall stop and SIGTRAP delivery */
	339	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD) ?
	340	0x80 : 0));
	341
	342	/*
	343	* this isn't the same as continuing with a signal, but it will do
	344	* for normal use. strace only continues with a signal if the
	345	* stopping signal is not SIGTRAP. -brl
	346	*/
	347	if (current->exit_code) {
	348	send_sig(current->exit_code, current, 1);
	349	current->exit_code = 0;
	350	}
2fd6f58b	351	out:
	352	if (unlikely(current->audit_context) && !entryexit)
	353	audit_syscall_entry(current, audit_arch(), regs->regs[2],
	354	regs->regs[4], regs->regs[5],
	355	regs->regs[6], regs->regs[7]);
1da177e4	356	}