xref: /openbmc/linux/arch/mips/kernel/ptrace32.c (revision 87c2ce3b)
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>
27 
28 #include <asm/cpu.h>
29 #include <asm/dsp.h>
30 #include <asm/fpu.h>
31 #include <asm/mipsregs.h>
32 #include <asm/mipsmtregs.h>
33 #include <asm/pgtable.h>
34 #include <asm/page.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/bootinfo.h>
38 
39 int ptrace_getregs (struct task_struct *child, __s64 __user *data);
40 int ptrace_setregs (struct task_struct *child, __s64 __user *data);
41 
42 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data);
43 int ptrace_setfpregs (struct task_struct *child, __u32 __user *data);
44 
45 /*
46  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
47  * work.  I don't know how to fix this.
48  */
49 asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
50 {
51 	struct task_struct *child;
52 	int ret;
53 
54 #if 0
55 	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
56 	       (int) request, (int) pid, (unsigned long) addr,
57 	       (unsigned long) data);
58 #endif
59 	lock_kernel();
60 	if (request == PTRACE_TRACEME) {
61 		ret = ptrace_traceme();
62 		goto out;
63 	}
64 
65 	child = ptrace_get_task_struct(pid);
66 	if (IS_ERR(child)) {
67 		ret = PTR_ERR(child);
68 		goto out;
69 	}
70 
71 	if (request == PTRACE_ATTACH) {
72 		ret = ptrace_attach(child);
73 		goto out_tsk;
74 	}
75 
76 	ret = ptrace_check_attach(child, request == PTRACE_KILL);
77 	if (ret < 0)
78 		goto out_tsk;
79 
80 	switch (request) {
81 	/* when I and D space are separate, these will need to be fixed. */
82 	case PTRACE_PEEKTEXT: /* read word at location addr. */
83 	case PTRACE_PEEKDATA: {
84 		unsigned int tmp;
85 		int copied;
86 
87 		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
88 		ret = -EIO;
89 		if (copied != sizeof(tmp))
90 			break;
91 		ret = put_user(tmp, (unsigned int *) (unsigned long) data);
92 		break;
93 	}
94 
95 	/*
96 	 * Read 4 bytes of the other process' storage
97 	 *  data is a pointer specifying where the user wants the
98 	 *	4 bytes copied into
99 	 *  addr is a pointer in the user's storage that contains an 8 byte
100 	 *	address in the other process of the 4 bytes that is to be read
101 	 * (this is run in a 32-bit process looking at a 64-bit process)
102 	 * when I and D space are separate, these will need to be fixed.
103 	 */
104 	case PTRACE_PEEKTEXT_3264:
105 	case PTRACE_PEEKDATA_3264: {
106 		u32 tmp;
107 		int copied;
108 		u32 __user * addrOthers;
109 
110 		ret = -EIO;
111 
112 		/* Get the addr in the other process that we want to read */
113 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
114 			break;
115 
116 		copied = access_process_vm(child, (u64)addrOthers, &tmp,
117 				sizeof(tmp), 0);
118 		if (copied != sizeof(tmp))
119 			break;
120 		ret = put_user(tmp, (u32 __user *) (unsigned long) data);
121 		break;
122 	}
123 
124 	/* Read the word at location addr in the USER area. */
125 	case PTRACE_PEEKUSR: {
126 		struct pt_regs *regs;
127 		unsigned int tmp;
128 
129 		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
130 		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
131 		ret = 0;  /* Default return value. */
132 
133 		switch (addr) {
134 		case 0 ... 31:
135 			tmp = regs->regs[addr];
136 			break;
137 		case FPR_BASE ... FPR_BASE + 31:
138 			if (tsk_used_math(child)) {
139 				fpureg_t *fregs = get_fpu_regs(child);
140 
141 				/*
142 				 * The odd registers are actually the high
143 				 * order bits of the values stored in the even
144 				 * registers - unless we're using r2k_switch.S.
145 				 */
146 				if (addr & 1)
147 					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
148 				else
149 					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
150 			} else {
151 				tmp = -1;	/* FP not yet used  */
152 			}
153 			break;
154 		case PC:
155 			tmp = regs->cp0_epc;
156 			break;
157 		case CAUSE:
158 			tmp = regs->cp0_cause;
159 			break;
160 		case BADVADDR:
161 			tmp = regs->cp0_badvaddr;
162 			break;
163 		case MMHI:
164 			tmp = regs->hi;
165 			break;
166 		case MMLO:
167 			tmp = regs->lo;
168 			break;
169 		case FPC_CSR:
170 			if (cpu_has_fpu)
171 				tmp = child->thread.fpu.hard.fcr31;
172 			else
173 				tmp = child->thread.fpu.soft.fcr31;
174 			break;
175 		case FPC_EIR: {	/* implementation / version register */
176 			unsigned int flags;
177 
178 			if (!cpu_has_fpu)
179 				break;
180 
181 			preempt_disable();
182 			if (cpu_has_mipsmt) {
183 				unsigned int vpflags = dvpe();
184 				flags = read_c0_status();
185 				__enable_fpu();
186 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
187 				write_c0_status(flags);
188 				evpe(vpflags);
189 			} else {
190 				flags = read_c0_status();
191 				__enable_fpu();
192 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
193 				write_c0_status(flags);
194 			}
195 			preempt_enable();
196 			break;
197 		}
198 		case DSP_BASE ... DSP_BASE + 5:
199 			if (!cpu_has_dsp) {
200 				tmp = 0;
201 				ret = -EIO;
202 				goto out_tsk;
203 			}
204 			if (child->thread.dsp.used_dsp) {
205 				dspreg_t *dregs = __get_dsp_regs(child);
206 				tmp = (unsigned long) (dregs[addr - DSP_BASE]);
207 			} else {
208 				tmp = -1;	/* DSP registers yet used  */
209 			}
210 			break;
211 		case DSP_CONTROL:
212 			if (!cpu_has_dsp) {
213 				tmp = 0;
214 				ret = -EIO;
215 				goto out_tsk;
216 			}
217 			tmp = child->thread.dsp.dspcontrol;
218 			break;
219 		default:
220 			tmp = 0;
221 			ret = -EIO;
222 			goto out_tsk;
223 		}
224 		ret = put_user(tmp, (unsigned *) (unsigned long) data);
225 		break;
226 	}
227 
228 	/* when I and D space are separate, this will have to be fixed. */
229 	case PTRACE_POKETEXT: /* write the word at location addr. */
230 	case PTRACE_POKEDATA:
231 		ret = 0;
232 		if (access_process_vm(child, addr, &data, sizeof(data), 1)
233 		    == sizeof(data))
234 			break;
235 		ret = -EIO;
236 		break;
237 
238 	/*
239 	 * Write 4 bytes into the other process' storage
240 	 *  data is the 4 bytes that the user wants written
241 	 *  addr is a pointer in the user's storage that contains an
242 	 *	8 byte address in the other process where the 4 bytes
243 	 *	that is to be written
244 	 * (this is run in a 32-bit process looking at a 64-bit process)
245 	 * when I and D space are separate, these will need to be fixed.
246 	 */
247 	case PTRACE_POKETEXT_3264:
248 	case PTRACE_POKEDATA_3264: {
249 		u32 __user * addrOthers;
250 
251 		/* Get the addr in the other process that we want to write into */
252 		ret = -EIO;
253 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
254 			break;
255 		ret = 0;
256 		if (access_process_vm(child, (u64)addrOthers, &data,
257 					sizeof(data), 1) == sizeof(data))
258 			break;
259 		ret = -EIO;
260 		break;
261 	}
262 
263 	case PTRACE_POKEUSR: {
264 		struct pt_regs *regs;
265 		ret = 0;
266 		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
267 		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
268 
269 		switch (addr) {
270 		case 0 ... 31:
271 			regs->regs[addr] = data;
272 			break;
273 		case FPR_BASE ... FPR_BASE + 31: {
274 			fpureg_t *fregs = get_fpu_regs(child);
275 
276 			if (!tsk_used_math(child)) {
277 				/* FP not yet used  */
278 				memset(&child->thread.fpu.hard, ~0,
279 				       sizeof(child->thread.fpu.hard));
280 				child->thread.fpu.hard.fcr31 = 0;
281 			}
282 			/*
283 			 * The odd registers are actually the high order bits
284 			 * of the values stored in the even registers - unless
285 			 * we're using r2k_switch.S.
286 			 */
287 			if (addr & 1) {
288 				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
289 				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
290 			} else {
291 				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
292 				/* Must cast, lest sign extension fill upper
293 				   bits!  */
294 				fregs[addr - FPR_BASE] |= (unsigned int)data;
295 			}
296 			break;
297 		}
298 		case PC:
299 			regs->cp0_epc = data;
300 			break;
301 		case MMHI:
302 			regs->hi = data;
303 			break;
304 		case MMLO:
305 			regs->lo = data;
306 			break;
307 		case FPC_CSR:
308 			if (cpu_has_fpu)
309 				child->thread.fpu.hard.fcr31 = data;
310 			else
311 				child->thread.fpu.soft.fcr31 = data;
312 			break;
313 		case DSP_BASE ... DSP_BASE + 5:
314 			if (!cpu_has_dsp) {
315 				ret = -EIO;
316 				break;
317 			}
318 
319 			dspreg_t *dregs = __get_dsp_regs(child);
320 			dregs[addr - DSP_BASE] = data;
321 			break;
322 		case DSP_CONTROL:
323 			if (!cpu_has_dsp) {
324 				ret = -EIO;
325 				break;
326 			}
327 			child->thread.dsp.dspcontrol = data;
328 			break;
329 		default:
330 			/* The rest are not allowed. */
331 			ret = -EIO;
332 			break;
333 		}
334 		break;
335 		}
336 
337 	case PTRACE_GETREGS:
338 		ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
339 		break;
340 
341 	case PTRACE_SETREGS:
342 		ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
343 		break;
344 
345 	case PTRACE_GETFPREGS:
346 		ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
347 		break;
348 
349 	case PTRACE_SETFPREGS:
350 		ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
351 		break;
352 
353 	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
354 	case PTRACE_CONT: { /* restart after signal. */
355 		ret = -EIO;
356 		if (!valid_signal(data))
357 			break;
358 		if (request == PTRACE_SYSCALL) {
359 			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
360 		}
361 		else {
362 			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
363 		}
364 		child->exit_code = data;
365 		wake_up_process(child);
366 		ret = 0;
367 		break;
368 	}
369 
370 	/*
371 	 * make the child exit.  Best I can do is send it a sigkill.
372 	 * perhaps it should be put in the status that it wants to
373 	 * exit.
374 	 */
375 	case PTRACE_KILL:
376 		ret = 0;
377 		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
378 			break;
379 		child->exit_code = SIGKILL;
380 		wake_up_process(child);
381 		break;
382 
383 	case PTRACE_GET_THREAD_AREA:
384 		ret = put_user(child->thread_info->tp_value,
385 				(unsigned int __user *) (unsigned long) data);
386 		break;
387 
388 	case PTRACE_DETACH: /* detach a process that was attached. */
389 		ret = ptrace_detach(child, data);
390 		break;
391 
392 	case PTRACE_GETEVENTMSG:
393 		ret = put_user(child->ptrace_message,
394 			       (unsigned int __user *) (unsigned long) data);
395 		break;
396 
397 	case PTRACE_GET_THREAD_AREA_3264:
398 		ret = put_user(child->thread_info->tp_value,
399 				(unsigned long __user *) (unsigned long) data);
400 		break;
401 
402 	default:
403 		ret = ptrace_request(child, request, addr, data);
404 		break;
405 	}
406 
407 out_tsk:
408 	put_task_struct(child);
409 out:
410 	unlock_kernel();
411 	return ret;
412 }
413