xref: /openbmc/linux/arch/parisc/kernel/ptrace.c (revision f8523d0e83613ab8d082cd504dc53a09fbba4889)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Kernel support for the ptrace() and syscall tracing interfaces.
4  *
5  * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
6  * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
7  * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
8  * Copyright (C) 2008-2016 Helge Deller <deller@gmx.de>
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/elf.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/tracehook.h>
19 #include <linux/user.h>
20 #include <linux/personality.h>
21 #include <linux/regset.h>
22 #include <linux/security.h>
23 #include <linux/seccomp.h>
24 #include <linux/compat.h>
25 #include <linux/signal.h>
26 #include <linux/audit.h>
27 
28 #include <linux/uaccess.h>
29 #include <asm/processor.h>
30 #include <asm/asm-offsets.h>
31 
32 /* PSW bits we allow the debugger to modify */
33 #define USER_PSW_BITS	(PSW_N | PSW_B | PSW_V | PSW_CB)
34 
35 #define CREATE_TRACE_POINTS
36 #include <trace/events/syscalls.h>
37 
38 /*
39  * These are our native regset flavors.
40  */
41 enum parisc_regset {
42 	REGSET_GENERAL,
43 	REGSET_FP
44 };
45 
46 /*
47  * Called by kernel/ptrace.c when detaching..
48  *
49  * Make sure single step bits etc are not set.
50  */
51 void ptrace_disable(struct task_struct *task)
52 {
53 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
54 	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
55 
56 	/* make sure the trap bits are not set */
57 	pa_psw(task)->r = 0;
58 	pa_psw(task)->t = 0;
59 	pa_psw(task)->h = 0;
60 	pa_psw(task)->l = 0;
61 }
62 
63 /*
64  * The following functions are called by ptrace_resume() when
65  * enabling or disabling single/block tracing.
66  */
67 void user_disable_single_step(struct task_struct *task)
68 {
69 	ptrace_disable(task);
70 }
71 
72 void user_enable_single_step(struct task_struct *task)
73 {
74 	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
75 	set_tsk_thread_flag(task, TIF_SINGLESTEP);
76 
77 	if (pa_psw(task)->n) {
78 		/* Nullified, just crank over the queue. */
79 		task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
80 		task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
81 		task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
82 		pa_psw(task)->n = 0;
83 		pa_psw(task)->x = 0;
84 		pa_psw(task)->y = 0;
85 		pa_psw(task)->z = 0;
86 		pa_psw(task)->b = 0;
87 		ptrace_disable(task);
88 		/* Don't wake up the task, but let the
89 		   parent know something happened. */
90 		force_sig_fault_to_task(SIGTRAP, TRAP_TRACE,
91 					(void __user *) (task_regs(task)->iaoq[0] & ~3),
92 					task);
93 		/* notify_parent(task, SIGCHLD); */
94 		return;
95 	}
96 
97 	/* Enable recovery counter traps.  The recovery counter
98 	 * itself will be set to zero on a task switch.  If the
99 	 * task is suspended on a syscall then the syscall return
100 	 * path will overwrite the recovery counter with a suitable
101 	 * value such that it traps once back in user space.  We
102 	 * disable interrupts in the tasks PSW here also, to avoid
103 	 * interrupts while the recovery counter is decrementing.
104 	 */
105 	pa_psw(task)->r = 1;
106 	pa_psw(task)->t = 0;
107 	pa_psw(task)->h = 0;
108 	pa_psw(task)->l = 0;
109 }
110 
111 void user_enable_block_step(struct task_struct *task)
112 {
113 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
114 	set_tsk_thread_flag(task, TIF_BLOCKSTEP);
115 
116 	/* Enable taken branch trap. */
117 	pa_psw(task)->r = 0;
118 	pa_psw(task)->t = 1;
119 	pa_psw(task)->h = 0;
120 	pa_psw(task)->l = 0;
121 }
122 
123 long arch_ptrace(struct task_struct *child, long request,
124 		 unsigned long addr, unsigned long data)
125 {
126 	unsigned long __user *datap = (unsigned long __user *)data;
127 	unsigned long tmp;
128 	long ret = -EIO;
129 
130 	switch (request) {
131 
132 	/* Read the word at location addr in the USER area.  For ptraced
133 	   processes, the kernel saves all regs on a syscall. */
134 	case PTRACE_PEEKUSR:
135 		if ((addr & (sizeof(unsigned long)-1)) ||
136 		     addr >= sizeof(struct pt_regs))
137 			break;
138 		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
139 		ret = put_user(tmp, datap);
140 		break;
141 
142 	/* Write the word at location addr in the USER area.  This will need
143 	   to change when the kernel no longer saves all regs on a syscall.
144 	   FIXME.  There is a problem at the moment in that r3-r18 are only
145 	   saved if the process is ptraced on syscall entry, and even then
146 	   those values are overwritten by actual register values on syscall
147 	   exit. */
148 	case PTRACE_POKEUSR:
149 		/* Some register values written here may be ignored in
150 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
151 		 * r31/r31+4, and not with the values in pt_regs.
152 		 */
153 		if (addr == PT_PSW) {
154 			/* Allow writing to Nullify, Divide-step-correction,
155 			 * and carry/borrow bits.
156 			 * BEWARE, if you set N, and then single step, it won't
157 			 * stop on the nullified instruction.
158 			 */
159 			data &= USER_PSW_BITS;
160 			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
161 			task_regs(child)->gr[0] |= data;
162 			ret = 0;
163 			break;
164 		}
165 
166 		if ((addr & (sizeof(unsigned long)-1)) ||
167 		     addr >= sizeof(struct pt_regs))
168 			break;
169 		if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
170 			data |= 3; /* ensure userspace privilege */
171 		}
172 		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
173 				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
174 				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
175 				addr == PT_SAR) {
176 			*(unsigned long *) ((char *) task_regs(child) + addr) = data;
177 			ret = 0;
178 		}
179 		break;
180 
181 	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
182 		return copy_regset_to_user(child,
183 					   task_user_regset_view(current),
184 					   REGSET_GENERAL,
185 					   0, sizeof(struct user_regs_struct),
186 					   datap);
187 
188 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
189 		return copy_regset_from_user(child,
190 					     task_user_regset_view(current),
191 					     REGSET_GENERAL,
192 					     0, sizeof(struct user_regs_struct),
193 					     datap);
194 
195 	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
196 		return copy_regset_to_user(child,
197 					   task_user_regset_view(current),
198 					   REGSET_FP,
199 					   0, sizeof(struct user_fp_struct),
200 					   datap);
201 
202 	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
203 		return copy_regset_from_user(child,
204 					     task_user_regset_view(current),
205 					     REGSET_FP,
206 					     0, sizeof(struct user_fp_struct),
207 					     datap);
208 
209 	default:
210 		ret = ptrace_request(child, request, addr, data);
211 		break;
212 	}
213 
214 	return ret;
215 }
216 
217 
218 #ifdef CONFIG_COMPAT
219 
220 /* This function is needed to translate 32 bit pt_regs offsets in to
221  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
222  * will request offset 12 if it wants gr3, but the lower 32 bits of
223  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
224  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
225  * except for the fp registers which (a) are 64 bits, and (b) follow
226  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
227  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
228  * being 64 bit in both cases.
229  */
230 
231 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
232 {
233 	compat_ulong_t pos;
234 
235 	if (offset < 32*4)	/* gr[0..31] */
236 		pos = offset * 2 + 4;
237 	else if (offset < 32*4+32*8)	/* fr[0] ... fr[31] */
238 		pos = (offset - 32*4) + PT_FR0;
239 	else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
240 		pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
241 	else
242 		pos = sizeof(struct pt_regs);
243 
244 	return pos;
245 }
246 
247 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
248 			compat_ulong_t addr, compat_ulong_t data)
249 {
250 	compat_uint_t tmp;
251 	long ret = -EIO;
252 
253 	switch (request) {
254 
255 	case PTRACE_PEEKUSR:
256 		if (addr & (sizeof(compat_uint_t)-1))
257 			break;
258 		addr = translate_usr_offset(addr);
259 		if (addr >= sizeof(struct pt_regs))
260 			break;
261 
262 		tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
263 		ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
264 		break;
265 
266 	/* Write the word at location addr in the USER area.  This will need
267 	   to change when the kernel no longer saves all regs on a syscall.
268 	   FIXME.  There is a problem at the moment in that r3-r18 are only
269 	   saved if the process is ptraced on syscall entry, and even then
270 	   those values are overwritten by actual register values on syscall
271 	   exit. */
272 	case PTRACE_POKEUSR:
273 		/* Some register values written here may be ignored in
274 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
275 		 * r31/r31+4, and not with the values in pt_regs.
276 		 */
277 		if (addr == PT_PSW) {
278 			/* Since PT_PSW==0, it is valid for 32 bit processes
279 			 * under 64 bit kernels as well.
280 			 */
281 			ret = arch_ptrace(child, request, addr, data);
282 		} else {
283 			if (addr & (sizeof(compat_uint_t)-1))
284 				break;
285 			addr = translate_usr_offset(addr);
286 			if (addr >= sizeof(struct pt_regs))
287 				break;
288 			if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
289 				data |= 3; /* ensure userspace privilege */
290 			}
291 			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
292 				/* Special case, fp regs are 64 bits anyway */
293 				*(__u32 *) ((char *) task_regs(child) + addr) = data;
294 				ret = 0;
295 			}
296 			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
297 					addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
298 					addr == PT_SAR+4) {
299 				/* Zero the top 32 bits */
300 				*(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
301 				*(__u32 *) ((char *) task_regs(child) + addr) = data;
302 				ret = 0;
303 			}
304 		}
305 		break;
306 
307 	default:
308 		ret = compat_ptrace_request(child, request, addr, data);
309 		break;
310 	}
311 
312 	return ret;
313 }
314 #endif
315 
316 long do_syscall_trace_enter(struct pt_regs *regs)
317 {
318 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
319 		int rc = tracehook_report_syscall_entry(regs);
320 
321 		/*
322 		 * As tracesys_next does not set %r28 to -ENOSYS
323 		 * when %r20 is set to -1, initialize it here.
324 		 */
325 		regs->gr[28] = -ENOSYS;
326 
327 		if (rc) {
328 			/*
329 			 * A nonzero return code from
330 			 * tracehook_report_syscall_entry() tells us
331 			 * to prevent the syscall execution.  Skip
332 			 * the syscall call and the syscall restart handling.
333 			 *
334 			 * Note that the tracer may also just change
335 			 * regs->gr[20] to an invalid syscall number,
336 			 * that is handled by tracesys_next.
337 			 */
338 			regs->gr[20] = -1UL;
339 			return -1;
340 		}
341 	}
342 
343 	/* Do the secure computing check after ptrace. */
344 	if (secure_computing() == -1)
345 		return -1;
346 
347 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
348 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
349 		trace_sys_enter(regs, regs->gr[20]);
350 #endif
351 
352 #ifdef CONFIG_64BIT
353 	if (!is_compat_task())
354 		audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
355 				    regs->gr[24], regs->gr[23]);
356 	else
357 #endif
358 		audit_syscall_entry(regs->gr[20] & 0xffffffff,
359 			regs->gr[26] & 0xffffffff,
360 			regs->gr[25] & 0xffffffff,
361 			regs->gr[24] & 0xffffffff,
362 			regs->gr[23] & 0xffffffff);
363 
364 	/*
365 	 * Sign extend the syscall number to 64bit since it may have been
366 	 * modified by a compat ptrace call
367 	 */
368 	return (int) ((u32) regs->gr[20]);
369 }
370 
371 void do_syscall_trace_exit(struct pt_regs *regs)
372 {
373 	int stepping = test_thread_flag(TIF_SINGLESTEP) ||
374 		test_thread_flag(TIF_BLOCKSTEP);
375 
376 	audit_syscall_exit(regs);
377 
378 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
379 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
380 		trace_sys_exit(regs, regs->gr[20]);
381 #endif
382 
383 	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
384 		tracehook_report_syscall_exit(regs, stepping);
385 }
386 
387 
388 /*
389  * regset functions.
390  */
391 
392 static int fpr_get(struct task_struct *target,
393 		     const struct user_regset *regset,
394 		     unsigned int pos, unsigned int count,
395 		     void *kbuf, void __user *ubuf)
396 {
397 	struct pt_regs *regs = task_regs(target);
398 	__u64 *k = kbuf;
399 	__u64 __user *u = ubuf;
400 	__u64 reg;
401 
402 	pos /= sizeof(reg);
403 	count /= sizeof(reg);
404 
405 	if (kbuf)
406 		for (; count > 0 && pos < ELF_NFPREG; --count)
407 			*k++ = regs->fr[pos++];
408 	else
409 		for (; count > 0 && pos < ELF_NFPREG; --count)
410 			if (__put_user(regs->fr[pos++], u++))
411 				return -EFAULT;
412 
413 	kbuf = k;
414 	ubuf = u;
415 	pos *= sizeof(reg);
416 	count *= sizeof(reg);
417 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
418 					ELF_NFPREG * sizeof(reg), -1);
419 }
420 
421 static int fpr_set(struct task_struct *target,
422 		     const struct user_regset *regset,
423 		     unsigned int pos, unsigned int count,
424 		     const void *kbuf, const void __user *ubuf)
425 {
426 	struct pt_regs *regs = task_regs(target);
427 	const __u64 *k = kbuf;
428 	const __u64 __user *u = ubuf;
429 	__u64 reg;
430 
431 	pos /= sizeof(reg);
432 	count /= sizeof(reg);
433 
434 	if (kbuf)
435 		for (; count > 0 && pos < ELF_NFPREG; --count)
436 			regs->fr[pos++] = *k++;
437 	else
438 		for (; count > 0 && pos < ELF_NFPREG; --count) {
439 			if (__get_user(reg, u++))
440 				return -EFAULT;
441 			regs->fr[pos++] = reg;
442 		}
443 
444 	kbuf = k;
445 	ubuf = u;
446 	pos *= sizeof(reg);
447 	count *= sizeof(reg);
448 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
449 					 ELF_NFPREG * sizeof(reg), -1);
450 }
451 
452 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
453 
454 static unsigned long get_reg(struct pt_regs *regs, int num)
455 {
456 	switch (num) {
457 	case RI(gr[0]) ... RI(gr[31]):	return regs->gr[num - RI(gr[0])];
458 	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
459 	case RI(iasq[0]):		return regs->iasq[0];
460 	case RI(iasq[1]):		return regs->iasq[1];
461 	case RI(iaoq[0]):		return regs->iaoq[0];
462 	case RI(iaoq[1]):		return regs->iaoq[1];
463 	case RI(sar):			return regs->sar;
464 	case RI(iir):			return regs->iir;
465 	case RI(isr):			return regs->isr;
466 	case RI(ior):			return regs->ior;
467 	case RI(ipsw):			return regs->ipsw;
468 	case RI(cr27):			return regs->cr27;
469 	case RI(cr0):			return mfctl(0);
470 	case RI(cr24):			return mfctl(24);
471 	case RI(cr25):			return mfctl(25);
472 	case RI(cr26):			return mfctl(26);
473 	case RI(cr28):			return mfctl(28);
474 	case RI(cr29):			return mfctl(29);
475 	case RI(cr30):			return mfctl(30);
476 	case RI(cr31):			return mfctl(31);
477 	case RI(cr8):			return mfctl(8);
478 	case RI(cr9):			return mfctl(9);
479 	case RI(cr12):			return mfctl(12);
480 	case RI(cr13):			return mfctl(13);
481 	case RI(cr10):			return mfctl(10);
482 	case RI(cr15):			return mfctl(15);
483 	default:			return 0;
484 	}
485 }
486 
487 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
488 {
489 	switch (num) {
490 	case RI(gr[0]): /*
491 			 * PSW is in gr[0].
492 			 * Allow writing to Nullify, Divide-step-correction,
493 			 * and carry/borrow bits.
494 			 * BEWARE, if you set N, and then single step, it won't
495 			 * stop on the nullified instruction.
496 			 */
497 			val &= USER_PSW_BITS;
498 			regs->gr[0] &= ~USER_PSW_BITS;
499 			regs->gr[0] |= val;
500 			return;
501 	case RI(gr[1]) ... RI(gr[31]):
502 			regs->gr[num - RI(gr[0])] = val;
503 			return;
504 	case RI(iaoq[0]):
505 	case RI(iaoq[1]):
506 			/* set 2 lowest bits to ensure userspace privilege: */
507 			regs->iaoq[num - RI(iaoq[0])] = val | 3;
508 			return;
509 	case RI(sar):	regs->sar = val;
510 			return;
511 	default:	return;
512 #if 0
513 	/* do not allow to change any of the following registers (yet) */
514 	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
515 	case RI(iasq[0]):		return regs->iasq[0];
516 	case RI(iasq[1]):		return regs->iasq[1];
517 	case RI(iir):			return regs->iir;
518 	case RI(isr):			return regs->isr;
519 	case RI(ior):			return regs->ior;
520 	case RI(ipsw):			return regs->ipsw;
521 	case RI(cr27):			return regs->cr27;
522         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
523         case cr8, cr9, cr12, cr13, cr10, cr15;
524 #endif
525 	}
526 }
527 
528 static int gpr_get(struct task_struct *target,
529 		     const struct user_regset *regset,
530 		     unsigned int pos, unsigned int count,
531 		     void *kbuf, void __user *ubuf)
532 {
533 	struct pt_regs *regs = task_regs(target);
534 	unsigned long *k = kbuf;
535 	unsigned long __user *u = ubuf;
536 	unsigned long reg;
537 
538 	pos /= sizeof(reg);
539 	count /= sizeof(reg);
540 
541 	if (kbuf)
542 		for (; count > 0 && pos < ELF_NGREG; --count)
543 			*k++ = get_reg(regs, pos++);
544 	else
545 		for (; count > 0 && pos < ELF_NGREG; --count)
546 			if (__put_user(get_reg(regs, pos++), u++))
547 				return -EFAULT;
548 	kbuf = k;
549 	ubuf = u;
550 	pos *= sizeof(reg);
551 	count *= sizeof(reg);
552 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
553 					ELF_NGREG * sizeof(reg), -1);
554 }
555 
556 static int gpr_set(struct task_struct *target,
557 		     const struct user_regset *regset,
558 		     unsigned int pos, unsigned int count,
559 		     const void *kbuf, const void __user *ubuf)
560 {
561 	struct pt_regs *regs = task_regs(target);
562 	const unsigned long *k = kbuf;
563 	const unsigned long __user *u = ubuf;
564 	unsigned long reg;
565 
566 	pos /= sizeof(reg);
567 	count /= sizeof(reg);
568 
569 	if (kbuf)
570 		for (; count > 0 && pos < ELF_NGREG; --count)
571 			set_reg(regs, pos++, *k++);
572 	else
573 		for (; count > 0 && pos < ELF_NGREG; --count) {
574 			if (__get_user(reg, u++))
575 				return -EFAULT;
576 			set_reg(regs, pos++, reg);
577 		}
578 
579 	kbuf = k;
580 	ubuf = u;
581 	pos *= sizeof(reg);
582 	count *= sizeof(reg);
583 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
584 					 ELF_NGREG * sizeof(reg), -1);
585 }
586 
587 static const struct user_regset native_regsets[] = {
588 	[REGSET_GENERAL] = {
589 		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
590 		.size = sizeof(long), .align = sizeof(long),
591 		.get = gpr_get, .set = gpr_set
592 	},
593 	[REGSET_FP] = {
594 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
595 		.size = sizeof(__u64), .align = sizeof(__u64),
596 		.get = fpr_get, .set = fpr_set
597 	}
598 };
599 
600 static const struct user_regset_view user_parisc_native_view = {
601 	.name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
602 	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
603 };
604 
605 #ifdef CONFIG_64BIT
606 #include <linux/compat.h>
607 
608 static int gpr32_get(struct task_struct *target,
609 		     const struct user_regset *regset,
610 		     unsigned int pos, unsigned int count,
611 		     void *kbuf, void __user *ubuf)
612 {
613 	struct pt_regs *regs = task_regs(target);
614 	compat_ulong_t *k = kbuf;
615 	compat_ulong_t __user *u = ubuf;
616 	compat_ulong_t reg;
617 
618 	pos /= sizeof(reg);
619 	count /= sizeof(reg);
620 
621 	if (kbuf)
622 		for (; count > 0 && pos < ELF_NGREG; --count)
623 			*k++ = get_reg(regs, pos++);
624 	else
625 		for (; count > 0 && pos < ELF_NGREG; --count)
626 			if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
627 				return -EFAULT;
628 
629 	kbuf = k;
630 	ubuf = u;
631 	pos *= sizeof(reg);
632 	count *= sizeof(reg);
633 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
634 					ELF_NGREG * sizeof(reg), -1);
635 }
636 
637 static int gpr32_set(struct task_struct *target,
638 		     const struct user_regset *regset,
639 		     unsigned int pos, unsigned int count,
640 		     const void *kbuf, const void __user *ubuf)
641 {
642 	struct pt_regs *regs = task_regs(target);
643 	const compat_ulong_t *k = kbuf;
644 	const compat_ulong_t __user *u = ubuf;
645 	compat_ulong_t reg;
646 
647 	pos /= sizeof(reg);
648 	count /= sizeof(reg);
649 
650 	if (kbuf)
651 		for (; count > 0 && pos < ELF_NGREG; --count)
652 			set_reg(regs, pos++, *k++);
653 	else
654 		for (; count > 0 && pos < ELF_NGREG; --count) {
655 			if (__get_user(reg, u++))
656 				return -EFAULT;
657 			set_reg(regs, pos++, reg);
658 		}
659 
660 	kbuf = k;
661 	ubuf = u;
662 	pos *= sizeof(reg);
663 	count *= sizeof(reg);
664 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
665 					 ELF_NGREG * sizeof(reg), -1);
666 }
667 
668 /*
669  * These are the regset flavors matching the 32bit native set.
670  */
671 static const struct user_regset compat_regsets[] = {
672 	[REGSET_GENERAL] = {
673 		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
674 		.size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
675 		.get = gpr32_get, .set = gpr32_set
676 	},
677 	[REGSET_FP] = {
678 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
679 		.size = sizeof(__u64), .align = sizeof(__u64),
680 		.get = fpr_get, .set = fpr_set
681 	}
682 };
683 
684 static const struct user_regset_view user_parisc_compat_view = {
685 	.name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
686 	.regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
687 };
688 #endif	/* CONFIG_64BIT */
689 
690 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
691 {
692 	BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
693 	BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
694 #ifdef CONFIG_64BIT
695 	if (is_compat_task())
696 		return &user_parisc_compat_view;
697 #endif
698 	return &user_parisc_native_view;
699 }
700 
701 
702 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
703 
704 struct pt_regs_offset {
705 	const char *name;
706 	int offset;
707 };
708 
709 #define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
710 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
711 #define REG_OFFSET_END {.name = NULL, .offset = 0}
712 
713 static const struct pt_regs_offset regoffset_table[] = {
714 	REG_OFFSET_INDEX(gr,0),
715 	REG_OFFSET_INDEX(gr,1),
716 	REG_OFFSET_INDEX(gr,2),
717 	REG_OFFSET_INDEX(gr,3),
718 	REG_OFFSET_INDEX(gr,4),
719 	REG_OFFSET_INDEX(gr,5),
720 	REG_OFFSET_INDEX(gr,6),
721 	REG_OFFSET_INDEX(gr,7),
722 	REG_OFFSET_INDEX(gr,8),
723 	REG_OFFSET_INDEX(gr,9),
724 	REG_OFFSET_INDEX(gr,10),
725 	REG_OFFSET_INDEX(gr,11),
726 	REG_OFFSET_INDEX(gr,12),
727 	REG_OFFSET_INDEX(gr,13),
728 	REG_OFFSET_INDEX(gr,14),
729 	REG_OFFSET_INDEX(gr,15),
730 	REG_OFFSET_INDEX(gr,16),
731 	REG_OFFSET_INDEX(gr,17),
732 	REG_OFFSET_INDEX(gr,18),
733 	REG_OFFSET_INDEX(gr,19),
734 	REG_OFFSET_INDEX(gr,20),
735 	REG_OFFSET_INDEX(gr,21),
736 	REG_OFFSET_INDEX(gr,22),
737 	REG_OFFSET_INDEX(gr,23),
738 	REG_OFFSET_INDEX(gr,24),
739 	REG_OFFSET_INDEX(gr,25),
740 	REG_OFFSET_INDEX(gr,26),
741 	REG_OFFSET_INDEX(gr,27),
742 	REG_OFFSET_INDEX(gr,28),
743 	REG_OFFSET_INDEX(gr,29),
744 	REG_OFFSET_INDEX(gr,30),
745 	REG_OFFSET_INDEX(gr,31),
746 	REG_OFFSET_INDEX(sr,0),
747 	REG_OFFSET_INDEX(sr,1),
748 	REG_OFFSET_INDEX(sr,2),
749 	REG_OFFSET_INDEX(sr,3),
750 	REG_OFFSET_INDEX(sr,4),
751 	REG_OFFSET_INDEX(sr,5),
752 	REG_OFFSET_INDEX(sr,6),
753 	REG_OFFSET_INDEX(sr,7),
754 	REG_OFFSET_INDEX(iasq,0),
755 	REG_OFFSET_INDEX(iasq,1),
756 	REG_OFFSET_INDEX(iaoq,0),
757 	REG_OFFSET_INDEX(iaoq,1),
758 	REG_OFFSET_NAME(cr27),
759 	REG_OFFSET_NAME(ksp),
760 	REG_OFFSET_NAME(kpc),
761 	REG_OFFSET_NAME(sar),
762 	REG_OFFSET_NAME(iir),
763 	REG_OFFSET_NAME(isr),
764 	REG_OFFSET_NAME(ior),
765 	REG_OFFSET_NAME(ipsw),
766 	REG_OFFSET_END,
767 };
768 
769 /**
770  * regs_query_register_offset() - query register offset from its name
771  * @name:	the name of a register
772  *
773  * regs_query_register_offset() returns the offset of a register in struct
774  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
775  */
776 int regs_query_register_offset(const char *name)
777 {
778 	const struct pt_regs_offset *roff;
779 	for (roff = regoffset_table; roff->name != NULL; roff++)
780 		if (!strcmp(roff->name, name))
781 			return roff->offset;
782 	return -EINVAL;
783 }
784 
785 /**
786  * regs_query_register_name() - query register name from its offset
787  * @offset:	the offset of a register in struct pt_regs.
788  *
789  * regs_query_register_name() returns the name of a register from its
790  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
791  */
792 const char *regs_query_register_name(unsigned int offset)
793 {
794 	const struct pt_regs_offset *roff;
795 	for (roff = regoffset_table; roff->name != NULL; roff++)
796 		if (roff->offset == offset)
797 			return roff->name;
798 	return NULL;
799 }
800 
801 /**
802  * regs_within_kernel_stack() - check the address in the stack
803  * @regs:      pt_regs which contains kernel stack pointer.
804  * @addr:      address which is checked.
805  *
806  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
807  * If @addr is within the kernel stack, it returns true. If not, returns false.
808  */
809 int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
810 {
811 	return ((addr & ~(THREAD_SIZE - 1))  ==
812 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
813 }
814 
815 /**
816  * regs_get_kernel_stack_nth() - get Nth entry of the stack
817  * @regs:	pt_regs which contains kernel stack pointer.
818  * @n:		stack entry number.
819  *
820  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
821  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
822  * this returns 0.
823  */
824 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
825 {
826 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
827 
828 	addr -= n;
829 
830 	if (!regs_within_kernel_stack(regs, (unsigned long)addr))
831 		return 0;
832 
833 	return *addr;
834 }
835