xref: /linux/arch/mips/kernel/ptrace32.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
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/compat.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/smp.h>
25 #include <linux/smp_lock.h>
26 #include <linux/user.h>
27 #include <linux/security.h>
28 
29 #include <asm/cpu.h>
30 #include <asm/dsp.h>
31 #include <asm/fpu.h>
32 #include <asm/mipsregs.h>
33 #include <asm/mipsmtregs.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  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
42  * work.  I don't know how to fix this.
43  */
44 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
45 			compat_ulong_t caddr, compat_ulong_t cdata)
46 {
47 	int addr = caddr;
48 	int data = cdata;
49 	int ret;
50 
51 	switch (request) {
52 	/* when I and D space are separate, these will need to be fixed. */
53 	case PTRACE_PEEKTEXT: /* read word at location addr. */
54 	case PTRACE_PEEKDATA: {
55 		unsigned int tmp;
56 		int copied;
57 
58 		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
59 		ret = -EIO;
60 		if (copied != sizeof(tmp))
61 			break;
62 		ret = put_user(tmp, (unsigned int __user *) (unsigned long) data);
63 		break;
64 	}
65 
66 	/*
67 	 * Read 4 bytes of the other process' storage
68 	 *  data is a pointer specifying where the user wants the
69 	 *	4 bytes copied into
70 	 *  addr is a pointer in the user's storage that contains an 8 byte
71 	 *	address in the other process of the 4 bytes that is to be read
72 	 * (this is run in a 32-bit process looking at a 64-bit process)
73 	 * when I and D space are separate, these will need to be fixed.
74 	 */
75 	case PTRACE_PEEKTEXT_3264:
76 	case PTRACE_PEEKDATA_3264: {
77 		u32 tmp;
78 		int copied;
79 		u32 __user * addrOthers;
80 
81 		ret = -EIO;
82 
83 		/* Get the addr in the other process that we want to read */
84 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
85 			break;
86 
87 		copied = access_process_vm(child, (u64)addrOthers, &tmp,
88 				sizeof(tmp), 0);
89 		if (copied != sizeof(tmp))
90 			break;
91 		ret = put_user(tmp, (u32 __user *) (unsigned long) data);
92 		break;
93 	}
94 
95 	/* Read the word at location addr in the USER area. */
96 	case PTRACE_PEEKUSR: {
97 		struct pt_regs *regs;
98 		unsigned int tmp;
99 
100 		regs = task_pt_regs(child);
101 		ret = 0;  /* Default return value. */
102 
103 		switch (addr) {
104 		case 0 ... 31:
105 			tmp = regs->regs[addr];
106 			break;
107 		case FPR_BASE ... FPR_BASE + 31:
108 			if (tsk_used_math(child)) {
109 				fpureg_t *fregs = get_fpu_regs(child);
110 
111 				/*
112 				 * The odd registers are actually the high
113 				 * order bits of the values stored in the even
114 				 * registers - unless we're using r2k_switch.S.
115 				 */
116 				if (addr & 1)
117 					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
118 				else
119 					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
120 			} else {
121 				tmp = -1;	/* FP not yet used  */
122 			}
123 			break;
124 		case PC:
125 			tmp = regs->cp0_epc;
126 			break;
127 		case CAUSE:
128 			tmp = regs->cp0_cause;
129 			break;
130 		case BADVADDR:
131 			tmp = regs->cp0_badvaddr;
132 			break;
133 		case MMHI:
134 			tmp = regs->hi;
135 			break;
136 		case MMLO:
137 			tmp = regs->lo;
138 			break;
139 		case FPC_CSR:
140 			tmp = child->thread.fpu.fcr31;
141 			break;
142 		case FPC_EIR: {	/* implementation / version register */
143 			unsigned int flags;
144 #ifdef CONFIG_MIPS_MT_SMTC
145 			unsigned int irqflags;
146 			unsigned int mtflags;
147 #endif /* CONFIG_MIPS_MT_SMTC */
148 
149 			preempt_disable();
150 			if (!cpu_has_fpu) {
151 				preempt_enable();
152 				tmp = 0;
153 				break;
154 			}
155 
156 #ifdef CONFIG_MIPS_MT_SMTC
157 			/* Read-modify-write of Status must be atomic */
158 			local_irq_save(irqflags);
159 			mtflags = dmt();
160 #endif /* CONFIG_MIPS_MT_SMTC */
161 
162 			if (cpu_has_mipsmt) {
163 				unsigned int vpflags = dvpe();
164 				flags = read_c0_status();
165 				__enable_fpu();
166 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
167 				write_c0_status(flags);
168 				evpe(vpflags);
169 			} else {
170 				flags = read_c0_status();
171 				__enable_fpu();
172 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
173 				write_c0_status(flags);
174 			}
175 #ifdef CONFIG_MIPS_MT_SMTC
176 			emt(mtflags);
177 			local_irq_restore(irqflags);
178 #endif /* CONFIG_MIPS_MT_SMTC */
179 			preempt_enable();
180 			break;
181 		}
182 		case DSP_BASE ... DSP_BASE + 5: {
183 			dspreg_t *dregs;
184 
185 			if (!cpu_has_dsp) {
186 				tmp = 0;
187 				ret = -EIO;
188 				goto out;
189 			}
190 			dregs = __get_dsp_regs(child);
191 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
192 			break;
193 		}
194 		case DSP_CONTROL:
195 			if (!cpu_has_dsp) {
196 				tmp = 0;
197 				ret = -EIO;
198 				goto out;
199 			}
200 			tmp = child->thread.dsp.dspcontrol;
201 			break;
202 		default:
203 			tmp = 0;
204 			ret = -EIO;
205 			goto out;
206 		}
207 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
208 		break;
209 	}
210 
211 	/* when I and D space are separate, this will have to be fixed. */
212 	case PTRACE_POKETEXT: /* write the word at location addr. */
213 	case PTRACE_POKEDATA:
214 		ret = 0;
215 		if (access_process_vm(child, addr, &data, sizeof(data), 1)
216 		    == sizeof(data))
217 			break;
218 		ret = -EIO;
219 		break;
220 
221 	/*
222 	 * Write 4 bytes into the other process' storage
223 	 *  data is the 4 bytes that the user wants written
224 	 *  addr is a pointer in the user's storage that contains an
225 	 *	8 byte address in the other process where the 4 bytes
226 	 *	that is to be written
227 	 * (this is run in a 32-bit process looking at a 64-bit process)
228 	 * when I and D space are separate, these will need to be fixed.
229 	 */
230 	case PTRACE_POKETEXT_3264:
231 	case PTRACE_POKEDATA_3264: {
232 		u32 __user * addrOthers;
233 
234 		/* Get the addr in the other process that we want to write into */
235 		ret = -EIO;
236 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
237 			break;
238 		ret = 0;
239 		if (access_process_vm(child, (u64)addrOthers, &data,
240 					sizeof(data), 1) == sizeof(data))
241 			break;
242 		ret = -EIO;
243 		break;
244 	}
245 
246 	case PTRACE_POKEUSR: {
247 		struct pt_regs *regs;
248 		ret = 0;
249 		regs = task_pt_regs(child);
250 
251 		switch (addr) {
252 		case 0 ... 31:
253 			regs->regs[addr] = data;
254 			break;
255 		case FPR_BASE ... FPR_BASE + 31: {
256 			fpureg_t *fregs = get_fpu_regs(child);
257 
258 			if (!tsk_used_math(child)) {
259 				/* FP not yet used  */
260 				memset(&child->thread.fpu, ~0,
261 				       sizeof(child->thread.fpu));
262 				child->thread.fpu.fcr31 = 0;
263 			}
264 			/*
265 			 * The odd registers are actually the high order bits
266 			 * of the values stored in the even registers - unless
267 			 * we're using r2k_switch.S.
268 			 */
269 			if (addr & 1) {
270 				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
271 				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
272 			} else {
273 				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
274 				/* Must cast, lest sign extension fill upper
275 				   bits!  */
276 				fregs[addr - FPR_BASE] |= (unsigned int)data;
277 			}
278 			break;
279 		}
280 		case PC:
281 			regs->cp0_epc = data;
282 			break;
283 		case MMHI:
284 			regs->hi = data;
285 			break;
286 		case MMLO:
287 			regs->lo = data;
288 			break;
289 		case FPC_CSR:
290 			child->thread.fpu.fcr31 = data;
291 			break;
292 		case DSP_BASE ... DSP_BASE + 5: {
293 			dspreg_t *dregs;
294 
295 			if (!cpu_has_dsp) {
296 				ret = -EIO;
297 				break;
298 			}
299 
300 			dregs = __get_dsp_regs(child);
301 			dregs[addr - DSP_BASE] = data;
302 			break;
303 		}
304 		case DSP_CONTROL:
305 			if (!cpu_has_dsp) {
306 				ret = -EIO;
307 				break;
308 			}
309 			child->thread.dsp.dspcontrol = data;
310 			break;
311 		default:
312 			/* The rest are not allowed. */
313 			ret = -EIO;
314 			break;
315 		}
316 		break;
317 		}
318 
319 	case PTRACE_GETREGS:
320 		ret = ptrace_getregs(child, (__s64 __user *) (__u64) data);
321 		break;
322 
323 	case PTRACE_SETREGS:
324 		ret = ptrace_setregs(child, (__s64 __user *) (__u64) data);
325 		break;
326 
327 	case PTRACE_GETFPREGS:
328 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
329 		break;
330 
331 	case PTRACE_SETFPREGS:
332 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
333 		break;
334 
335 	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
336 	case PTRACE_CONT: { /* restart after signal. */
337 		ret = -EIO;
338 		if (!valid_signal(data))
339 			break;
340 		if (request == PTRACE_SYSCALL) {
341 			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
342 		}
343 		else {
344 			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
345 		}
346 		child->exit_code = data;
347 		wake_up_process(child);
348 		ret = 0;
349 		break;
350 	}
351 
352 	/*
353 	 * make the child exit.  Best I can do is send it a sigkill.
354 	 * perhaps it should be put in the status that it wants to
355 	 * exit.
356 	 */
357 	case PTRACE_KILL:
358 		ret = 0;
359 		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
360 			break;
361 		child->exit_code = SIGKILL;
362 		wake_up_process(child);
363 		break;
364 
365 	case PTRACE_GET_THREAD_AREA:
366 		ret = put_user(task_thread_info(child)->tp_value,
367 				(unsigned int __user *) (unsigned long) data);
368 		break;
369 
370 	case PTRACE_DETACH: /* detach a process that was attached. */
371 		ret = ptrace_detach(child, data);
372 		break;
373 
374 	case PTRACE_GETEVENTMSG:
375 		ret = put_user(child->ptrace_message,
376 			       (unsigned int __user *) (unsigned long) data);
377 		break;
378 
379 	case PTRACE_GET_THREAD_AREA_3264:
380 		ret = put_user(task_thread_info(child)->tp_value,
381 				(unsigned long __user *) (unsigned long) data);
382 		break;
383 
384 	case PTRACE_GET_WATCH_REGS:
385 		ret = ptrace_get_watch_regs(child,
386 			(struct pt_watch_regs __user *) (unsigned long) addr);
387 		break;
388 
389 	case PTRACE_SET_WATCH_REGS:
390 		ret = ptrace_set_watch_regs(child,
391 			(struct pt_watch_regs __user *) (unsigned long) addr);
392 		break;
393 
394 	default:
395 		ret = ptrace_request(child, request, addr, data);
396 		break;
397 	}
398 out:
399 	return ret;
400 }
401