xref: /openbmc/linux/arch/sparc/kernel/ptrace_32.c (revision e2c75e76)
1 // SPDX-License-Identifier: GPL-2.0
2 /* ptrace.c: Sparc process tracing support.
3  *
4  * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
5  *
6  * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
7  * and David Mosberger.
8  *
9  * Added Linux support -miguel (weird, eh?, the original code was meant
10  * to emulate SunOS).
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/mm.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/user.h>
19 #include <linux/smp.h>
20 #include <linux/security.h>
21 #include <linux/signal.h>
22 #include <linux/regset.h>
23 #include <linux/elf.h>
24 #include <linux/tracehook.h>
25 
26 #include <asm/pgtable.h>
27 #include <linux/uaccess.h>
28 #include <asm/cacheflush.h>
29 
30 #include "kernel.h"
31 
32 /* #define ALLOW_INIT_TRACING */
33 
34 /*
35  * Called by kernel/ptrace.c when detaching..
36  *
37  * Make sure single step bits etc are not set.
38  */
39 void ptrace_disable(struct task_struct *child)
40 {
41 	/* nothing to do */
42 }
43 
44 enum sparc_regset {
45 	REGSET_GENERAL,
46 	REGSET_FP,
47 };
48 
49 static int genregs32_get(struct task_struct *target,
50 			 const struct user_regset *regset,
51 			 unsigned int pos, unsigned int count,
52 			 void *kbuf, void __user *ubuf)
53 {
54 	const struct pt_regs *regs = target->thread.kregs;
55 	unsigned long __user *reg_window;
56 	unsigned long *k = kbuf;
57 	unsigned long __user *u = ubuf;
58 	unsigned long reg;
59 
60 	if (target == current)
61 		flush_user_windows();
62 
63 	pos /= sizeof(reg);
64 	count /= sizeof(reg);
65 
66 	if (kbuf) {
67 		for (; count > 0 && pos < 16; count--)
68 			*k++ = regs->u_regs[pos++];
69 
70 		reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
71 		reg_window -= 16;
72 		for (; count > 0 && pos < 32; count--) {
73 			if (get_user(*k++, &reg_window[pos++]))
74 				return -EFAULT;
75 		}
76 	} else {
77 		for (; count > 0 && pos < 16; count--) {
78 			if (put_user(regs->u_regs[pos++], u++))
79 				return -EFAULT;
80 		}
81 
82 		reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
83 		reg_window -= 16;
84 		for (; count > 0 && pos < 32; count--) {
85 			if (get_user(reg, &reg_window[pos++]) ||
86 			    put_user(reg, u++))
87 				return -EFAULT;
88 		}
89 	}
90 	while (count > 0) {
91 		switch (pos) {
92 		case 32: /* PSR */
93 			reg = regs->psr;
94 			break;
95 		case 33: /* PC */
96 			reg = regs->pc;
97 			break;
98 		case 34: /* NPC */
99 			reg = regs->npc;
100 			break;
101 		case 35: /* Y */
102 			reg = regs->y;
103 			break;
104 		case 36: /* WIM */
105 		case 37: /* TBR */
106 			reg = 0;
107 			break;
108 		default:
109 			goto finish;
110 		}
111 
112 		if (kbuf)
113 			*k++ = reg;
114 		else if (put_user(reg, u++))
115 			return -EFAULT;
116 		pos++;
117 		count--;
118 	}
119 finish:
120 	pos *= sizeof(reg);
121 	count *= sizeof(reg);
122 
123 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
124 					38 * sizeof(reg), -1);
125 }
126 
127 static int genregs32_set(struct task_struct *target,
128 			 const struct user_regset *regset,
129 			 unsigned int pos, unsigned int count,
130 			 const void *kbuf, const void __user *ubuf)
131 {
132 	struct pt_regs *regs = target->thread.kregs;
133 	unsigned long __user *reg_window;
134 	const unsigned long *k = kbuf;
135 	const unsigned long __user *u = ubuf;
136 	unsigned long reg;
137 
138 	if (target == current)
139 		flush_user_windows();
140 
141 	pos /= sizeof(reg);
142 	count /= sizeof(reg);
143 
144 	if (kbuf) {
145 		for (; count > 0 && pos < 16; count--)
146 			regs->u_regs[pos++] = *k++;
147 
148 		reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
149 		reg_window -= 16;
150 		for (; count > 0 && pos < 32; count--) {
151 			if (put_user(*k++, &reg_window[pos++]))
152 				return -EFAULT;
153 		}
154 	} else {
155 		for (; count > 0 && pos < 16; count--) {
156 			if (get_user(reg, u++))
157 				return -EFAULT;
158 			regs->u_regs[pos++] = reg;
159 		}
160 
161 		reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
162 		reg_window -= 16;
163 		for (; count > 0 && pos < 32; count--) {
164 			if (get_user(reg, u++) ||
165 			    put_user(reg, &reg_window[pos++]))
166 				return -EFAULT;
167 		}
168 	}
169 	while (count > 0) {
170 		unsigned long psr;
171 
172 		if (kbuf)
173 			reg = *k++;
174 		else if (get_user(reg, u++))
175 			return -EFAULT;
176 
177 		switch (pos) {
178 		case 32: /* PSR */
179 			psr = regs->psr;
180 			psr &= ~(PSR_ICC | PSR_SYSCALL);
181 			psr |= (reg & (PSR_ICC | PSR_SYSCALL));
182 			regs->psr = psr;
183 			break;
184 		case 33: /* PC */
185 			regs->pc = reg;
186 			break;
187 		case 34: /* NPC */
188 			regs->npc = reg;
189 			break;
190 		case 35: /* Y */
191 			regs->y = reg;
192 			break;
193 		case 36: /* WIM */
194 		case 37: /* TBR */
195 			break;
196 		default:
197 			goto finish;
198 		}
199 
200 		pos++;
201 		count--;
202 	}
203 finish:
204 	pos *= sizeof(reg);
205 	count *= sizeof(reg);
206 
207 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
208 					 38 * sizeof(reg), -1);
209 }
210 
211 static int fpregs32_get(struct task_struct *target,
212 			const struct user_regset *regset,
213 			unsigned int pos, unsigned int count,
214 			void *kbuf, void __user *ubuf)
215 {
216 	const unsigned long *fpregs = target->thread.float_regs;
217 	int ret = 0;
218 
219 #if 0
220 	if (target == current)
221 		save_and_clear_fpu();
222 #endif
223 
224 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
225 				  fpregs,
226 				  0, 32 * sizeof(u32));
227 
228 	if (!ret)
229 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
230 					       32 * sizeof(u32),
231 					       33 * sizeof(u32));
232 	if (!ret)
233 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
234 					  &target->thread.fsr,
235 					  33 * sizeof(u32),
236 					  34 * sizeof(u32));
237 
238 	if (!ret) {
239 		unsigned long val;
240 
241 		val = (1 << 8) | (8 << 16);
242 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
243 					  &val,
244 					  34 * sizeof(u32),
245 					  35 * sizeof(u32));
246 	}
247 
248 	if (!ret)
249 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
250 					       35 * sizeof(u32), -1);
251 
252 	return ret;
253 }
254 
255 static int fpregs32_set(struct task_struct *target,
256 			const struct user_regset *regset,
257 			unsigned int pos, unsigned int count,
258 			const void *kbuf, const void __user *ubuf)
259 {
260 	unsigned long *fpregs = target->thread.float_regs;
261 	int ret;
262 
263 #if 0
264 	if (target == current)
265 		save_and_clear_fpu();
266 #endif
267 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
268 				 fpregs,
269 				 0, 32 * sizeof(u32));
270 	if (!ret)
271 		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
272 					  32 * sizeof(u32),
273 					  33 * sizeof(u32));
274 	if (!ret && count > 0) {
275 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
276 					 &target->thread.fsr,
277 					 33 * sizeof(u32),
278 					 34 * sizeof(u32));
279 	}
280 
281 	if (!ret)
282 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
283 						34 * sizeof(u32), -1);
284 	return ret;
285 }
286 
287 static const struct user_regset sparc32_regsets[] = {
288 	/* Format is:
289 	 * 	G0 --> G7
290 	 *	O0 --> O7
291 	 *	L0 --> L7
292 	 *	I0 --> I7
293 	 *	PSR, PC, nPC, Y, WIM, TBR
294 	 */
295 	[REGSET_GENERAL] = {
296 		.core_note_type = NT_PRSTATUS,
297 		.n = 38,
298 		.size = sizeof(u32), .align = sizeof(u32),
299 		.get = genregs32_get, .set = genregs32_set
300 	},
301 	/* Format is:
302 	 *	F0 --> F31
303 	 *	empty 32-bit word
304 	 *	FSR (32--bit word)
305 	 *	FPU QUEUE COUNT (8-bit char)
306 	 *	FPU QUEUE ENTRYSIZE (8-bit char)
307 	 *	FPU ENABLED (8-bit char)
308 	 *	empty 8-bit char
309 	 *	FPU QUEUE (64 32-bit ints)
310 	 */
311 	[REGSET_FP] = {
312 		.core_note_type = NT_PRFPREG,
313 		.n = 99,
314 		.size = sizeof(u32), .align = sizeof(u32),
315 		.get = fpregs32_get, .set = fpregs32_set
316 	},
317 };
318 
319 static const struct user_regset_view user_sparc32_view = {
320 	.name = "sparc", .e_machine = EM_SPARC,
321 	.regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
322 };
323 
324 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
325 {
326 	return &user_sparc32_view;
327 }
328 
329 struct fps {
330 	unsigned long regs[32];
331 	unsigned long fsr;
332 	unsigned long flags;
333 	unsigned long extra;
334 	unsigned long fpqd;
335 	struct fq {
336 		unsigned long *insnaddr;
337 		unsigned long insn;
338 	} fpq[16];
339 };
340 
341 long arch_ptrace(struct task_struct *child, long request,
342 		 unsigned long addr, unsigned long data)
343 {
344 	unsigned long addr2 = current->thread.kregs->u_regs[UREG_I4];
345 	void __user *addr2p;
346 	const struct user_regset_view *view;
347 	struct pt_regs __user *pregs;
348 	struct fps __user *fps;
349 	int ret;
350 
351 	view = task_user_regset_view(current);
352 	addr2p = (void __user *) addr2;
353 	pregs = (struct pt_regs __user *) addr;
354 	fps = (struct fps __user *) addr;
355 
356 	switch(request) {
357 	case PTRACE_GETREGS: {
358 		ret = copy_regset_to_user(child, view, REGSET_GENERAL,
359 					  32 * sizeof(u32),
360 					  4 * sizeof(u32),
361 					  &pregs->psr);
362 		if (!ret)
363 			copy_regset_to_user(child, view, REGSET_GENERAL,
364 					    1 * sizeof(u32),
365 					    15 * sizeof(u32),
366 					    &pregs->u_regs[0]);
367 		break;
368 	}
369 
370 	case PTRACE_SETREGS: {
371 		ret = copy_regset_from_user(child, view, REGSET_GENERAL,
372 					    32 * sizeof(u32),
373 					    4 * sizeof(u32),
374 					    &pregs->psr);
375 		if (!ret)
376 			copy_regset_from_user(child, view, REGSET_GENERAL,
377 					      1 * sizeof(u32),
378 					      15 * sizeof(u32),
379 					      &pregs->u_regs[0]);
380 		break;
381 	}
382 
383 	case PTRACE_GETFPREGS: {
384 		ret = copy_regset_to_user(child, view, REGSET_FP,
385 					  0 * sizeof(u32),
386 					  32 * sizeof(u32),
387 					  &fps->regs[0]);
388 		if (!ret)
389 			ret = copy_regset_to_user(child, view, REGSET_FP,
390 						  33 * sizeof(u32),
391 						  1 * sizeof(u32),
392 						  &fps->fsr);
393 
394 		if (!ret) {
395 			if (__put_user(0, &fps->fpqd) ||
396 			    __put_user(0, &fps->flags) ||
397 			    __put_user(0, &fps->extra) ||
398 			    clear_user(fps->fpq, sizeof(fps->fpq)))
399 				ret = -EFAULT;
400 		}
401 		break;
402 	}
403 
404 	case PTRACE_SETFPREGS: {
405 		ret = copy_regset_from_user(child, view, REGSET_FP,
406 					    0 * sizeof(u32),
407 					    32 * sizeof(u32),
408 					    &fps->regs[0]);
409 		if (!ret)
410 			ret = copy_regset_from_user(child, view, REGSET_FP,
411 						    33 * sizeof(u32),
412 						    1 * sizeof(u32),
413 						    &fps->fsr);
414 		break;
415 	}
416 
417 	case PTRACE_READTEXT:
418 	case PTRACE_READDATA:
419 		ret = ptrace_readdata(child, addr, addr2p, data);
420 
421 		if (ret == data)
422 			ret = 0;
423 		else if (ret >= 0)
424 			ret = -EIO;
425 		break;
426 
427 	case PTRACE_WRITETEXT:
428 	case PTRACE_WRITEDATA:
429 		ret = ptrace_writedata(child, addr2p, addr, data);
430 
431 		if (ret == data)
432 			ret = 0;
433 		else if (ret >= 0)
434 			ret = -EIO;
435 		break;
436 
437 	default:
438 		if (request == PTRACE_SPARC_DETACH)
439 			request = PTRACE_DETACH;
440 		ret = ptrace_request(child, request, addr, data);
441 		break;
442 	}
443 
444 	return ret;
445 }
446 
447 asmlinkage int syscall_trace(struct pt_regs *regs, int syscall_exit_p)
448 {
449 	int ret = 0;
450 
451 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
452 		if (syscall_exit_p)
453 			tracehook_report_syscall_exit(regs, 0);
454 		else
455 			ret = tracehook_report_syscall_entry(regs);
456 	}
457 
458 	return ret;
459 }
460