xref: /linux/arch/mips/kernel/ptrace32.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 __user *) (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 = task_pt_regs(child);
130 		ret = 0;  /* Default return value. */
131 
132 		switch (addr) {
133 		case 0 ... 31:
134 			tmp = regs->regs[addr];
135 			break;
136 		case FPR_BASE ... FPR_BASE + 31:
137 			if (tsk_used_math(child)) {
138 				fpureg_t *fregs = get_fpu_regs(child);
139 
140 				/*
141 				 * The odd registers are actually the high
142 				 * order bits of the values stored in the even
143 				 * registers - unless we're using r2k_switch.S.
144 				 */
145 				if (addr & 1)
146 					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
147 				else
148 					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
149 			} else {
150 				tmp = -1;	/* FP not yet used  */
151 			}
152 			break;
153 		case PC:
154 			tmp = regs->cp0_epc;
155 			break;
156 		case CAUSE:
157 			tmp = regs->cp0_cause;
158 			break;
159 		case BADVADDR:
160 			tmp = regs->cp0_badvaddr;
161 			break;
162 		case MMHI:
163 			tmp = regs->hi;
164 			break;
165 		case MMLO:
166 			tmp = regs->lo;
167 			break;
168 		case FPC_CSR:
169 			tmp = child->thread.fpu.fcr31;
170 			break;
171 		case FPC_EIR: {	/* implementation / version register */
172 			unsigned int flags;
173 #ifdef CONFIG_MIPS_MT_SMTC
174 			unsigned int irqflags;
175 			unsigned int mtflags;
176 #endif /* CONFIG_MIPS_MT_SMTC */
177 
178 			if (!cpu_has_fpu) {
179 				tmp = 0;
180 				break;
181 			}
182 
183 #ifdef CONFIG_MIPS_MT_SMTC
184 			/* Read-modify-write of Status must be atomic */
185 			local_irq_save(irqflags);
186 			mtflags = dmt();
187 #endif /* CONFIG_MIPS_MT_SMTC */
188 
189 			preempt_disable();
190 			if (cpu_has_mipsmt) {
191 				unsigned int vpflags = dvpe();
192 				flags = read_c0_status();
193 				__enable_fpu();
194 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
195 				write_c0_status(flags);
196 				evpe(vpflags);
197 			} else {
198 				flags = read_c0_status();
199 				__enable_fpu();
200 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
201 				write_c0_status(flags);
202 			}
203 #ifdef CONFIG_MIPS_MT_SMTC
204 			emt(mtflags);
205 			local_irq_restore(irqflags);
206 #endif /* CONFIG_MIPS_MT_SMTC */
207 			preempt_enable();
208 			break;
209 		}
210 		case DSP_BASE ... DSP_BASE + 5: {
211 			dspreg_t *dregs;
212 
213 			if (!cpu_has_dsp) {
214 				tmp = 0;
215 				ret = -EIO;
216 				goto out_tsk;
217 			}
218 			dregs = __get_dsp_regs(child);
219 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
220 			break;
221 		}
222 		case DSP_CONTROL:
223 			if (!cpu_has_dsp) {
224 				tmp = 0;
225 				ret = -EIO;
226 				goto out_tsk;
227 			}
228 			tmp = child->thread.dsp.dspcontrol;
229 			break;
230 		default:
231 			tmp = 0;
232 			ret = -EIO;
233 			goto out_tsk;
234 		}
235 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
236 		break;
237 	}
238 
239 	/* when I and D space are separate, this will have to be fixed. */
240 	case PTRACE_POKETEXT: /* write the word at location addr. */
241 	case PTRACE_POKEDATA:
242 		ret = 0;
243 		if (access_process_vm(child, addr, &data, sizeof(data), 1)
244 		    == sizeof(data))
245 			break;
246 		ret = -EIO;
247 		break;
248 
249 	/*
250 	 * Write 4 bytes into the other process' storage
251 	 *  data is the 4 bytes that the user wants written
252 	 *  addr is a pointer in the user's storage that contains an
253 	 *	8 byte address in the other process where the 4 bytes
254 	 *	that is to be written
255 	 * (this is run in a 32-bit process looking at a 64-bit process)
256 	 * when I and D space are separate, these will need to be fixed.
257 	 */
258 	case PTRACE_POKETEXT_3264:
259 	case PTRACE_POKEDATA_3264: {
260 		u32 __user * addrOthers;
261 
262 		/* Get the addr in the other process that we want to write into */
263 		ret = -EIO;
264 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
265 			break;
266 		ret = 0;
267 		if (access_process_vm(child, (u64)addrOthers, &data,
268 					sizeof(data), 1) == sizeof(data))
269 			break;
270 		ret = -EIO;
271 		break;
272 	}
273 
274 	case PTRACE_POKEUSR: {
275 		struct pt_regs *regs;
276 		ret = 0;
277 		regs = task_pt_regs(child);
278 
279 		switch (addr) {
280 		case 0 ... 31:
281 			regs->regs[addr] = data;
282 			break;
283 		case FPR_BASE ... FPR_BASE + 31: {
284 			fpureg_t *fregs = get_fpu_regs(child);
285 
286 			if (!tsk_used_math(child)) {
287 				/* FP not yet used  */
288 				memset(&child->thread.fpu, ~0,
289 				       sizeof(child->thread.fpu));
290 				child->thread.fpu.fcr31 = 0;
291 			}
292 			/*
293 			 * The odd registers are actually the high order bits
294 			 * of the values stored in the even registers - unless
295 			 * we're using r2k_switch.S.
296 			 */
297 			if (addr & 1) {
298 				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
299 				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
300 			} else {
301 				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
302 				/* Must cast, lest sign extension fill upper
303 				   bits!  */
304 				fregs[addr - FPR_BASE] |= (unsigned int)data;
305 			}
306 			break;
307 		}
308 		case PC:
309 			regs->cp0_epc = data;
310 			break;
311 		case MMHI:
312 			regs->hi = data;
313 			break;
314 		case MMLO:
315 			regs->lo = data;
316 			break;
317 		case FPC_CSR:
318 			child->thread.fpu.fcr31 = data;
319 			break;
320 		case DSP_BASE ... DSP_BASE + 5: {
321 			dspreg_t *dregs;
322 
323 			if (!cpu_has_dsp) {
324 				ret = -EIO;
325 				break;
326 			}
327 
328 			dregs = __get_dsp_regs(child);
329 			dregs[addr - DSP_BASE] = data;
330 			break;
331 		}
332 		case DSP_CONTROL:
333 			if (!cpu_has_dsp) {
334 				ret = -EIO;
335 				break;
336 			}
337 			child->thread.dsp.dspcontrol = data;
338 			break;
339 		default:
340 			/* The rest are not allowed. */
341 			ret = -EIO;
342 			break;
343 		}
344 		break;
345 		}
346 
347 	case PTRACE_GETREGS:
348 		ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
349 		break;
350 
351 	case PTRACE_SETREGS:
352 		ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
353 		break;
354 
355 	case PTRACE_GETFPREGS:
356 		ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
357 		break;
358 
359 	case PTRACE_SETFPREGS:
360 		ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
361 		break;
362 
363 	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
364 	case PTRACE_CONT: { /* restart after signal. */
365 		ret = -EIO;
366 		if (!valid_signal(data))
367 			break;
368 		if (request == PTRACE_SYSCALL) {
369 			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
370 		}
371 		else {
372 			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
373 		}
374 		child->exit_code = data;
375 		wake_up_process(child);
376 		ret = 0;
377 		break;
378 	}
379 
380 	/*
381 	 * make the child exit.  Best I can do is send it a sigkill.
382 	 * perhaps it should be put in the status that it wants to
383 	 * exit.
384 	 */
385 	case PTRACE_KILL:
386 		ret = 0;
387 		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
388 			break;
389 		child->exit_code = SIGKILL;
390 		wake_up_process(child);
391 		break;
392 
393 	case PTRACE_GET_THREAD_AREA:
394 		ret = put_user(task_thread_info(child)->tp_value,
395 				(unsigned int __user *) (unsigned long) data);
396 		break;
397 
398 	case PTRACE_DETACH: /* detach a process that was attached. */
399 		ret = ptrace_detach(child, data);
400 		break;
401 
402 	case PTRACE_GETEVENTMSG:
403 		ret = put_user(child->ptrace_message,
404 			       (unsigned int __user *) (unsigned long) data);
405 		break;
406 
407 	case PTRACE_GET_THREAD_AREA_3264:
408 		ret = put_user(task_thread_info(child)->tp_value,
409 				(unsigned long __user *) (unsigned long) data);
410 		break;
411 
412 	default:
413 		ret = ptrace_request(child, request, addr, data);
414 		break;
415 	}
416 
417 out_tsk:
418 	put_task_struct(child);
419 out:
420 	unlock_kernel();
421 	return ret;
422 }
423