xref: /openbmc/linux/arch/mips/kernel/ptrace32.c (revision 643d1f7f)
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 			preempt_disable();
179 			if (!cpu_has_fpu) {
180 				preempt_enable();
181 				tmp = 0;
182 				break;
183 			}
184 
185 #ifdef CONFIG_MIPS_MT_SMTC
186 			/* Read-modify-write of Status must be atomic */
187 			local_irq_save(irqflags);
188 			mtflags = dmt();
189 #endif /* CONFIG_MIPS_MT_SMTC */
190 
191 			if (cpu_has_mipsmt) {
192 				unsigned int vpflags = dvpe();
193 				flags = read_c0_status();
194 				__enable_fpu();
195 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
196 				write_c0_status(flags);
197 				evpe(vpflags);
198 			} else {
199 				flags = read_c0_status();
200 				__enable_fpu();
201 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
202 				write_c0_status(flags);
203 			}
204 #ifdef CONFIG_MIPS_MT_SMTC
205 			emt(mtflags);
206 			local_irq_restore(irqflags);
207 #endif /* CONFIG_MIPS_MT_SMTC */
208 			preempt_enable();
209 			break;
210 		}
211 		case DSP_BASE ... DSP_BASE + 5: {
212 			dspreg_t *dregs;
213 
214 			if (!cpu_has_dsp) {
215 				tmp = 0;
216 				ret = -EIO;
217 				goto out_tsk;
218 			}
219 			dregs = __get_dsp_regs(child);
220 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
221 			break;
222 		}
223 		case DSP_CONTROL:
224 			if (!cpu_has_dsp) {
225 				tmp = 0;
226 				ret = -EIO;
227 				goto out_tsk;
228 			}
229 			tmp = child->thread.dsp.dspcontrol;
230 			break;
231 		default:
232 			tmp = 0;
233 			ret = -EIO;
234 			goto out_tsk;
235 		}
236 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
237 		break;
238 	}
239 
240 	/* when I and D space are separate, this will have to be fixed. */
241 	case PTRACE_POKETEXT: /* write the word at location addr. */
242 	case PTRACE_POKEDATA:
243 		ret = 0;
244 		if (access_process_vm(child, addr, &data, sizeof(data), 1)
245 		    == sizeof(data))
246 			break;
247 		ret = -EIO;
248 		break;
249 
250 	/*
251 	 * Write 4 bytes into the other process' storage
252 	 *  data is the 4 bytes that the user wants written
253 	 *  addr is a pointer in the user's storage that contains an
254 	 *	8 byte address in the other process where the 4 bytes
255 	 *	that is to be written
256 	 * (this is run in a 32-bit process looking at a 64-bit process)
257 	 * when I and D space are separate, these will need to be fixed.
258 	 */
259 	case PTRACE_POKETEXT_3264:
260 	case PTRACE_POKEDATA_3264: {
261 		u32 __user * addrOthers;
262 
263 		/* Get the addr in the other process that we want to write into */
264 		ret = -EIO;
265 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
266 			break;
267 		ret = 0;
268 		if (access_process_vm(child, (u64)addrOthers, &data,
269 					sizeof(data), 1) == sizeof(data))
270 			break;
271 		ret = -EIO;
272 		break;
273 	}
274 
275 	case PTRACE_POKEUSR: {
276 		struct pt_regs *regs;
277 		ret = 0;
278 		regs = task_pt_regs(child);
279 
280 		switch (addr) {
281 		case 0 ... 31:
282 			regs->regs[addr] = data;
283 			break;
284 		case FPR_BASE ... FPR_BASE + 31: {
285 			fpureg_t *fregs = get_fpu_regs(child);
286 
287 			if (!tsk_used_math(child)) {
288 				/* FP not yet used  */
289 				memset(&child->thread.fpu, ~0,
290 				       sizeof(child->thread.fpu));
291 				child->thread.fpu.fcr31 = 0;
292 			}
293 			/*
294 			 * The odd registers are actually the high order bits
295 			 * of the values stored in the even registers - unless
296 			 * we're using r2k_switch.S.
297 			 */
298 			if (addr & 1) {
299 				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
300 				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
301 			} else {
302 				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
303 				/* Must cast, lest sign extension fill upper
304 				   bits!  */
305 				fregs[addr - FPR_BASE] |= (unsigned int)data;
306 			}
307 			break;
308 		}
309 		case PC:
310 			regs->cp0_epc = data;
311 			break;
312 		case MMHI:
313 			regs->hi = data;
314 			break;
315 		case MMLO:
316 			regs->lo = data;
317 			break;
318 		case FPC_CSR:
319 			child->thread.fpu.fcr31 = data;
320 			break;
321 		case DSP_BASE ... DSP_BASE + 5: {
322 			dspreg_t *dregs;
323 
324 			if (!cpu_has_dsp) {
325 				ret = -EIO;
326 				break;
327 			}
328 
329 			dregs = __get_dsp_regs(child);
330 			dregs[addr - DSP_BASE] = data;
331 			break;
332 		}
333 		case DSP_CONTROL:
334 			if (!cpu_has_dsp) {
335 				ret = -EIO;
336 				break;
337 			}
338 			child->thread.dsp.dspcontrol = data;
339 			break;
340 		default:
341 			/* The rest are not allowed. */
342 			ret = -EIO;
343 			break;
344 		}
345 		break;
346 		}
347 
348 	case PTRACE_GETREGS:
349 		ret = ptrace_getregs(child, (__s64 __user *) (__u64) data);
350 		break;
351 
352 	case PTRACE_SETREGS:
353 		ret = ptrace_setregs(child, (__s64 __user *) (__u64) data);
354 		break;
355 
356 	case PTRACE_GETFPREGS:
357 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
358 		break;
359 
360 	case PTRACE_SETFPREGS:
361 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
362 		break;
363 
364 	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
365 	case PTRACE_CONT: { /* restart after signal. */
366 		ret = -EIO;
367 		if (!valid_signal(data))
368 			break;
369 		if (request == PTRACE_SYSCALL) {
370 			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
371 		}
372 		else {
373 			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
374 		}
375 		child->exit_code = data;
376 		wake_up_process(child);
377 		ret = 0;
378 		break;
379 	}
380 
381 	/*
382 	 * make the child exit.  Best I can do is send it a sigkill.
383 	 * perhaps it should be put in the status that it wants to
384 	 * exit.
385 	 */
386 	case PTRACE_KILL:
387 		ret = 0;
388 		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
389 			break;
390 		child->exit_code = SIGKILL;
391 		wake_up_process(child);
392 		break;
393 
394 	case PTRACE_GET_THREAD_AREA:
395 		ret = put_user(task_thread_info(child)->tp_value,
396 				(unsigned int __user *) (unsigned long) data);
397 		break;
398 
399 	case PTRACE_DETACH: /* detach a process that was attached. */
400 		ret = ptrace_detach(child, data);
401 		break;
402 
403 	case PTRACE_GETEVENTMSG:
404 		ret = put_user(child->ptrace_message,
405 			       (unsigned int __user *) (unsigned long) data);
406 		break;
407 
408 	case PTRACE_GET_THREAD_AREA_3264:
409 		ret = put_user(task_thread_info(child)->tp_value,
410 				(unsigned long __user *) (unsigned long) data);
411 		break;
412 
413 	default:
414 		ret = ptrace_request(child, request, addr, data);
415 		break;
416 	}
417 
418 out_tsk:
419 	put_task_struct(child);
420 out:
421 	unlock_kernel();
422 	return ret;
423 }
424