[linux-2.6-block.git] / arch / mips / kernel / ptrace32.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/compiler.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.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>

/*
 * Tracing a 32-bit process with a 64-bit strace and vice versa will not
 * work.  I don't know how to fix this.
 */
asmlinkage int sys32_ptrace(int request, int pid, int addr, int 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 int 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 int *) (unsigned long) data);
		break;
	}

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

		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);

				/*
				 * 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);
			} 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 *) (unsigned long) 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;
			}
			/*
			 * 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;
				/* Must cast, lest sign extension fill upper
				   bits!  */
				fregs[addr - FPR_BASE] |= (unsigned int)data;
			}
			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;
}
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/compiler.h>
	18	#include <linux/kernel.h>
	19	#include <linux/sched.h>
	20	#include <linux/mm.h>
	21	#include <linux/errno.h>
	22	#include <linux/ptrace.h>
	23	#include <linux/smp.h>
	24	#include <linux/smp_lock.h>
	25	#include <linux/user.h>
	26	#include <linux/security.h>
7ed20e1a	27	#include <linux/signal.h>
1da177e4 LT	28
	29	#include <asm/cpu.h>
	30	#include <asm/fpu.h>
	31	#include <asm/mipsregs.h>
	32	#include <asm/pgtable.h>
	33	#include <asm/page.h>
	34	#include <asm/system.h>
	35	#include <asm/uaccess.h>
	36	#include <asm/bootinfo.h>
	37
	38	/*
	39	* Tracing a 32-bit process with a 64-bit strace and vice versa will not
	40	* work. I don't know how to fix this.
	41	*/
	42	asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
	43	{
	44	struct task_struct *child;
	45	int ret;
	46
	47	#if 0
	48	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
	49	(int) request, (int) pid, (unsigned long) addr,
	50	(unsigned long) data);
	51	#endif
	52	lock_kernel();
	53	ret = -EPERM;
	54	if (request == PTRACE_TRACEME) {
	55	/* are we already being traced? */
	56	if (current->ptrace & PT_PTRACED)
	57	goto out;
	58	if ((ret = security_ptrace(current->parent, current)))
	59	goto out;
	60	/* set the ptrace bit in the process flags. */
	61	current->ptrace \|= PT_PTRACED;
	62	ret = 0;
	63	goto out;
	64	}
	65	ret = -ESRCH;
	66	read_lock(&tasklist_lock);
	67	child = find_task_by_pid(pid);
	68	if (child)
	69	get_task_struct(child);
	70	read_unlock(&tasklist_lock);
	71	if (!child)
	72	goto out;
	73
	74	ret = -EPERM;
	75	if (pid == 1) /* you may not mess with init */
	76	goto out_tsk;
	77
	78	if (request == PTRACE_ATTACH) {
	79	ret = ptrace_attach(child);
	80	goto out_tsk;
	81	}
	82
	83	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	84	if (ret < 0)
	85	goto out_tsk;
	86
	87	switch (request) {
	88	/* when I and D space are separate, these will need to be fixed. */
	89	case PTRACE_PEEKTEXT: /* read word at location addr. */
	90	case PTRACE_PEEKDATA: {
	91	unsigned int tmp;
92	int copied;
93
94	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
95	ret = -EIO;
96	if (copied != sizeof(tmp))
97	break;
98	ret = put_user(tmp, (unsigned int *) (unsigned long) data);
99	break;
100	}
101
102	/* Read the word at location addr in the USER area. */
103	case PTRACE_PEEKUSR: {
104	struct pt_regs *regs;
105	unsigned int tmp;
106
107	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
108	THREAD_SIZE - 32 - sizeof(struct pt_regs));
109	ret = 0; /* Default return value. */
110
111	switch (addr) {
112	case 0 ... 31:
113	tmp = regs->regs[addr];
114	break;
115	case FPR_BASE ... FPR_BASE + 31:
116	if (tsk_used_math(child)) {
117	fpureg_t *fregs = get_fpu_regs(child);
118
119	/*
120	* The odd registers are actually the high
121	* order bits of the values stored in the even
122	* registers - unless we're using r2k_switch.S.
123	*/
124	if (addr & 1)
125	tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
126	else
127	tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
128	} else {
129	tmp = -1; /* FP not yet used */
130	}
131	break;
132	case PC:
133	tmp = regs->cp0_epc;
134	break;
135	case CAUSE:
136	tmp = regs->cp0_cause;
137	break;
138	case BADVADDR:
139	tmp = regs->cp0_badvaddr;
140	break;
141	case MMHI:
142	tmp = regs->hi;
143	break;
144	case MMLO:
145	tmp = regs->lo;
146	break;
147	case FPC_CSR:
148	if (cpu_has_fpu)
149	tmp = child->thread.fpu.hard.fcr31;
150	else
151	tmp = child->thread.fpu.soft.fcr31;
152	break;
153	case FPC_EIR: { /* implementation / version register */
154	unsigned int flags;
155
156	if (!cpu_has_fpu)
157	break;
158
159	flags = read_c0_status();
160	__enable_fpu();
161	__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
162	write_c0_status(flags);
163	break;
164	}
165	default:
166	tmp = 0;
167	ret = -EIO;
168	goto out_tsk;
169	}
170	ret = put_user(tmp, (unsigned *) (unsigned long) data);
171	break;
172	}
173
174	/* when I and D space are separate, this will have to be fixed. */
175	case PTRACE_POKETEXT: /* write the word at location addr. */
176	case PTRACE_POKEDATA:
177	ret = 0;
178	if (access_process_vm(child, addr, &data, sizeof(data), 1)
179	== sizeof(data))
180	break;
181	ret = -EIO;
182	break;
183
184	case PTRACE_POKEUSR: {
185	struct pt_regs *regs;
186	ret = 0;
187	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
188	THREAD_SIZE - 32 - sizeof(struct pt_regs));
189
190	switch (addr) {
191	case 0 ... 31:
192	regs->regs[addr] = data;
193	break;
194	case FPR_BASE ... FPR_BASE + 31: {
195	fpureg_t *fregs = get_fpu_regs(child);
196
197	if (!tsk_used_math(child)) {
198	/* FP not yet used */
199	memset(&child->thread.fpu.hard, ~0,
200	sizeof(child->thread.fpu.hard));
201	child->thread.fpu.hard.fcr31 = 0;
202	}
203	/*
204	* The odd registers are actually the high order bits
205	* of the values stored in the even registers - unless
206	* we're using r2k_switch.S.
207	*/
208	if (addr & 1) {
209	fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
210	fregs[(addr & ~1) - FPR_BASE] \|= ((unsigned long long) data) << 32;
211	} else {
212	fregs[addr - FPR_BASE] &= ~0xffffffffLL;
213	/* Must cast, lest sign extension fill upper
214	bits! */
215	fregs[addr - FPR_BASE] \|= (unsigned int)data;
216	}
217	break;
218	}
219	case PC:
220	regs->cp0_epc = data;
221	break;
222	case MMHI:
223	regs->hi = data;
224	break;
225	case MMLO:
226	regs->lo = data;
227	break;
228	case FPC_CSR:
229	if (cpu_has_fpu)
230	child->thread.fpu.hard.fcr31 = data;
231	else
232	child->thread.fpu.soft.fcr31 = data;
233	break;
234	default:
235	/* The rest are not allowed. */
236	ret = -EIO;
237	break;
238	}
239	break;
240	}
241
242	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
243	case PTRACE_CONT: { /* restart after signal. */
244	ret = -EIO;
7ed20e1a	245	if (!valid_signal(data))
1da177e4 LT	246	break;
	247	if (request == PTRACE_SYSCALL) {
	248	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	249	}
	250	else {
	251	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	252	}
	253	child->exit_code = data;
	254	wake_up_process(child);
	255	ret = 0;
	256	break;
	257	}
	258
	259	/*
	260	* make the child exit. Best I can do is send it a sigkill.
	261	* perhaps it should be put in the status that it wants to
	262	* exit.
	263	*/
	264	case PTRACE_KILL:
	265	ret = 0;
	266	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	267	break;
	268	child->exit_code = SIGKILL;
	269	wake_up_process(child);
	270	break;
	271
	272	case PTRACE_DETACH: /* detach a process that was attached. */
	273	ret = ptrace_detach(child, data);
	274	break;
	275
	276	default:
	277	ret = ptrace_request(child, request, addr, data);
	278	break;
	279	}
	280
	281	out_tsk:
	282	put_task_struct(child);
	283	out:
	284	unlock_kernel();
	285	return ret;
	286	}