[GitHub/mt8127/android_kernel_alcatel_ttab.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/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;

	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)
{
#ifdef CONFIG_CPU_LITTLE_ENDIAN
#ifdef CONFIG_64BIT
	if (!(current->thread.mflags & MF_32BIT_REGS))
		return AUDIT_ARCH_MIPSEL64;
#endif /* MIPS64 */
	return AUDIT_ARCH_MIPSEL;

#else /* big endian... */
#ifdef CONFIG_64BIT
	if (!(current->thread.mflags & MF_32BIT_REGS))
		return AUDIT_ARCH_MIPS64;
#endif /* MIPS64 */
	return AUDIT_ARCH_MIPS;

#endif /* endian */
}

/*
 * 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 (!test_thread_flag(TIF_SYSCALL_TRACE))
		goto out;
	if (!(current->ptrace & PT_PTRACED))
		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 LT	30
	31	#include <asm/cpu.h>
	32	#include <asm/fpu.h>
	33	#include <asm/mipsregs.h>
	34	#include <asm/pgtable.h>
	35	#include <asm/page.h>
	36	#include <asm/system.h>
	37	#include <asm/uaccess.h>
	38	#include <asm/bootinfo.h>
	39
	40	/*
	41	* Called by kernel/ptrace.c when detaching..
	42	*
	43	* Make sure single step bits etc are not set.
	44	*/
	45	void ptrace_disable(struct task_struct *child)
	46	{
	47	/* Nothing to do.. */
	48	}
	49
	50	asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
	51	{
	52	struct task_struct *child;
	53	int ret;
	54
	55	#if 0
	56	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
	57	(int) request, (int) pid, (unsigned long) addr,
	58	(unsigned long) data);
	59	#endif
	60	lock_kernel();
	61	ret = -EPERM;
	62	if (request == PTRACE_TRACEME) {
	63	/* are we already being traced? */
	64	if (current->ptrace & PT_PTRACED)
	65	goto out;
	66	if ((ret = security_ptrace(current->parent, current)))
	67	goto out;
	68	/* set the ptrace bit in the process flags. */
	69	current->ptrace \|= PT_PTRACED;
	70	ret = 0;
	71	goto out;
	72	}
	73	ret = -ESRCH;
	74	read_lock(&tasklist_lock);
	75	child = find_task_by_pid(pid);
	76	if (child)
	77	get_task_struct(child);
	78	read_unlock(&tasklist_lock);
	79	if (!child)
	80	goto out;
	81
	82	ret = -EPERM;
	83	if (pid == 1) /* you may not mess with init */
	84	goto out_tsk;
	85
	86	if (request == PTRACE_ATTACH) {
	87	ret = ptrace_attach(child);
	88	goto out_tsk;
	89	}
	90
	91	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	92	if (ret < 0)
	93	goto out_tsk;
94
95	switch (request) {
96	/* when I and D space are separate, these will need to be fixed. */
97	case PTRACE_PEEKTEXT: /* read word at location addr. */
98	case PTRACE_PEEKDATA: {
99	unsigned long tmp;
100	int copied;
101
102	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
103	ret = -EIO;
104	if (copied != sizeof(tmp))
105	break;
fe00f943	106	ret = put_user(tmp,(unsigned long __user *) data);
1da177e4 LT	107	break;
	108	}
	109
	110	/* Read the word at location addr in the USER area. */
	111	case PTRACE_PEEKUSR: {
	112	struct pt_regs *regs;
	113	unsigned long tmp = 0;
	114
	115	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
	116	THREAD_SIZE - 32 - sizeof(struct pt_regs));
	117	ret = 0; /* Default return value. */
	118
	119	switch (addr) {
	120	case 0 ... 31:
	121	tmp = regs->regs[addr];
	122	break;
	123	case FPR_BASE ... FPR_BASE + 31:
	124	if (tsk_used_math(child)) {
	125	fpureg_t *fregs = get_fpu_regs(child);
	126
875d43e7	127	#ifdef CONFIG_32BIT
1da177e4 LT	128	/*
	129	* The odd registers are actually the high
	130	* order bits of the values stored in the even
	131	* registers - unless we're using r2k_switch.S.
	132	*/
	133	if (addr & 1)
	134	tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
	135	else
	136	tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
	137	#endif
875d43e7	138	#ifdef CONFIG_64BIT
1da177e4 LT	139	tmp = fregs[addr - FPR_BASE];
	140	#endif
	141	} else {
	142	tmp = -1; /* FP not yet used */
	143	}
	144	break;
	145	case PC:
	146	tmp = regs->cp0_epc;
	147	break;
	148	case CAUSE:
	149	tmp = regs->cp0_cause;
	150	break;
	151	case BADVADDR:
	152	tmp = regs->cp0_badvaddr;
	153	break;
	154	case MMHI:
	155	tmp = regs->hi;
	156	break;
	157	case MMLO:
	158	tmp = regs->lo;
	159	break;
	160	case FPC_CSR:
	161	if (cpu_has_fpu)
	162	tmp = child->thread.fpu.hard.fcr31;
	163	else
	164	tmp = child->thread.fpu.soft.fcr31;
	165	break;
	166	case FPC_EIR: { /* implementation / version register */
	167	unsigned int flags;
	168
	169	if (!cpu_has_fpu)
	170	break;
	171
	172	flags = read_c0_status();
	173	__enable_fpu();
	174	__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
	175	write_c0_status(flags);
	176	break;
	177	}
	178	default:
	179	tmp = 0;
	180	ret = -EIO;
	181	goto out_tsk;
	182	}
fe00f943	183	ret = put_user(tmp, (unsigned long __user *) data);
1da177e4 LT	184	break;
	185	}
	186
	187	/* when I and D space are separate, this will have to be fixed. */
	188	case PTRACE_POKETEXT: /* write the word at location addr. */
	189	case PTRACE_POKEDATA:
	190	ret = 0;
	191	if (access_process_vm(child, addr, &data, sizeof(data), 1)
	192	== sizeof(data))
	193	break;
	194	ret = -EIO;
	195	break;
	196
	197	case PTRACE_POKEUSR: {
	198	struct pt_regs *regs;
	199	ret = 0;
	200	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
	201	THREAD_SIZE - 32 - sizeof(struct pt_regs));
	202
	203	switch (addr) {
	204	case 0 ... 31:
	205	regs->regs[addr] = data;
	206	break;
	207	case FPR_BASE ... FPR_BASE + 31: {
	208	fpureg_t *fregs = get_fpu_regs(child);
	209
	210	if (!tsk_used_math(child)) {
	211	/* FP not yet used */
	212	memset(&child->thread.fpu.hard, ~0,
	213	sizeof(child->thread.fpu.hard));
	214	child->thread.fpu.hard.fcr31 = 0;
	215	}
875d43e7	216	#ifdef CONFIG_32BIT
1da177e4 LT	217	/*
	218	* The odd registers are actually the high order bits
	219	* of the values stored in the even registers - unless
	220	* we're using r2k_switch.S.
	221	*/
	222	if (addr & 1) {
	223	fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
	224	fregs[(addr & ~1) - FPR_BASE] \|= ((unsigned long long) data) << 32;
	225	} else {
	226	fregs[addr - FPR_BASE] &= ~0xffffffffLL;
	227	fregs[addr - FPR_BASE] \|= data;
	228	}
	229	#endif
875d43e7	230	#ifdef CONFIG_64BIT
1da177e4 LT	231	fregs[addr - FPR_BASE] = data;
	232	#endif
	233	break;
	234	}
	235	case PC:
	236	regs->cp0_epc = data;
	237	break;
	238	case MMHI:
	239	regs->hi = data;
	240	break;
	241	case MMLO:
	242	regs->lo = data;
	243	break;
	244	case FPC_CSR:
	245	if (cpu_has_fpu)
	246	child->thread.fpu.hard.fcr31 = data;
	247	else
	248	child->thread.fpu.soft.fcr31 = data;
	249	break;
	250	default:
	251	/* The rest are not allowed. */
	252	ret = -EIO;
	253	break;
	254	}
	255	break;
	256	}
	257
	258	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	259	case PTRACE_CONT: { /* restart after signal. */
	260	ret = -EIO;
7ed20e1a	261	if (!valid_signal(data))
1da177e4 LT	262	break;
	263	if (request == PTRACE_SYSCALL) {
	264	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	265	}
	266	else {
	267	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	268	}
	269	child->exit_code = data;
	270	wake_up_process(child);
	271	ret = 0;
	272	break;
	273	}
	274
	275	/*
	276	* make the child exit. Best I can do is send it a sigkill.
	277	* perhaps it should be put in the status that it wants to
	278	* exit.
	279	*/
	280	case PTRACE_KILL:
	281	ret = 0;
	282	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	283	break;
	284	child->exit_code = SIGKILL;
	285	wake_up_process(child);
	286	break;
	287
	288	case PTRACE_DETACH: /* detach a process that was attached. */
	289	ret = ptrace_detach(child, data);
	290	break;
	291
	292	default:
	293	ret = ptrace_request(child, request, addr, data);
	294	break;
	295	}
	296
	297	out_tsk:
	298	put_task_struct(child);
	299	out:
	300	unlock_kernel();
	301	return ret;
	302	}
	303
67eb81e1	304	static inline int audit_arch(void)
2fd6f58b DW	305	{
2fd6f58b DW	306	#ifdef CONFIG_CPU_LITTLE_ENDIAN
875d43e7	307	#ifdef CONFIG_64BIT
2fd6f58b DW	308	if (!(current->thread.mflags & MF_32BIT_REGS))
	309	return AUDIT_ARCH_MIPSEL64;
	310	#endif /* MIPS64 */
	311	return AUDIT_ARCH_MIPSEL;
	312
	313	#else /* big endian... */
875d43e7	314	#ifdef CONFIG_64BIT
2fd6f58b DW	315	if (!(current->thread.mflags & MF_32BIT_REGS))
	316	return AUDIT_ARCH_MIPS64;
	317	#endif /* MIPS64 */
	318	return AUDIT_ARCH_MIPS;
	319
	320	#endif /* endian */
	321	}
	322
1da177e4 LT	323	/*
	324	* Notification of system call entry/exit
	325	* - triggered by current->work.syscall_trace
	326	*/
	327	asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
	328	{
2fd6f58b DW	329	if (unlikely(current->audit_context) && entryexit)
2fd6f58b DW	330	audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]), regs->regs[2]);
1da177e4 LT	331
1da177e4 LT	332	if (!test_thread_flag(TIF_SYSCALL_TRACE))
2fd6f58b	333	goto out;
1da177e4	334	if (!(current->ptrace & PT_PTRACED))
2fd6f58b	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 DW	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	}