xref: /openbmc/linux/arch/parisc/kernel/ptrace.c (revision da2ef666)
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/pgtable.h>
30 #include <asm/processor.h>
31 #include <asm/asm-offsets.h>
32 
33 /* PSW bits we allow the debugger to modify */
34 #define USER_PSW_BITS	(PSW_N | PSW_B | PSW_V | PSW_CB)
35 
36 #define CREATE_TRACE_POINTS
37 #include <trace/events/syscalls.h>
38 
39 /*
40  * These are our native regset flavors.
41  */
42 enum parisc_regset {
43 	REGSET_GENERAL,
44 	REGSET_FP
45 };
46 
47 /*
48  * Called by kernel/ptrace.c when detaching..
49  *
50  * Make sure single step bits etc are not set.
51  */
52 void ptrace_disable(struct task_struct *task)
53 {
54 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
55 	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
56 
57 	/* make sure the trap bits are not set */
58 	pa_psw(task)->r = 0;
59 	pa_psw(task)->t = 0;
60 	pa_psw(task)->h = 0;
61 	pa_psw(task)->l = 0;
62 }
63 
64 /*
65  * The following functions are called by ptrace_resume() when
66  * enabling or disabling single/block tracing.
67  */
68 void user_disable_single_step(struct task_struct *task)
69 {
70 	ptrace_disable(task);
71 }
72 
73 void user_enable_single_step(struct task_struct *task)
74 {
75 	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
76 	set_tsk_thread_flag(task, TIF_SINGLESTEP);
77 
78 	if (pa_psw(task)->n) {
79 		/* Nullified, just crank over the queue. */
80 		task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
81 		task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
82 		task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
83 		pa_psw(task)->n = 0;
84 		pa_psw(task)->x = 0;
85 		pa_psw(task)->y = 0;
86 		pa_psw(task)->z = 0;
87 		pa_psw(task)->b = 0;
88 		ptrace_disable(task);
89 		/* Don't wake up the task, but let the
90 		   parent know something happened. */
91 		force_sig_fault(SIGTRAP, TRAP_TRACE,
92 				(void __user *) (task_regs(task)->iaoq[0] & ~3),
93 				task);
94 		/* notify_parent(task, SIGCHLD); */
95 		return;
96 	}
97 
98 	/* Enable recovery counter traps.  The recovery counter
99 	 * itself will be set to zero on a task switch.  If the
100 	 * task is suspended on a syscall then the syscall return
101 	 * path will overwrite the recovery counter with a suitable
102 	 * value such that it traps once back in user space.  We
103 	 * disable interrupts in the tasks PSW here also, to avoid
104 	 * interrupts while the recovery counter is decrementing.
105 	 */
106 	pa_psw(task)->r = 1;
107 	pa_psw(task)->t = 0;
108 	pa_psw(task)->h = 0;
109 	pa_psw(task)->l = 0;
110 }
111 
112 void user_enable_block_step(struct task_struct *task)
113 {
114 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
115 	set_tsk_thread_flag(task, TIF_BLOCKSTEP);
116 
117 	/* Enable taken branch trap. */
118 	pa_psw(task)->r = 0;
119 	pa_psw(task)->t = 1;
120 	pa_psw(task)->h = 0;
121 	pa_psw(task)->l = 0;
122 }
123 
124 long arch_ptrace(struct task_struct *child, long request,
125 		 unsigned long addr, unsigned long data)
126 {
127 	unsigned long __user *datap = (unsigned long __user *)data;
128 	unsigned long tmp;
129 	long ret = -EIO;
130 
131 	switch (request) {
132 
133 	/* Read the word at location addr in the USER area.  For ptraced
134 	   processes, the kernel saves all regs on a syscall. */
135 	case PTRACE_PEEKUSR:
136 		if ((addr & (sizeof(unsigned long)-1)) ||
137 		     addr >= sizeof(struct pt_regs))
138 			break;
139 		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
140 		ret = put_user(tmp, datap);
141 		break;
142 
143 	/* Write the word at location addr in the USER area.  This will need
144 	   to change when the kernel no longer saves all regs on a syscall.
145 	   FIXME.  There is a problem at the moment in that r3-r18 are only
146 	   saved if the process is ptraced on syscall entry, and even then
147 	   those values are overwritten by actual register values on syscall
148 	   exit. */
149 	case PTRACE_POKEUSR:
150 		/* Some register values written here may be ignored in
151 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
152 		 * r31/r31+4, and not with the values in pt_regs.
153 		 */
154 		if (addr == PT_PSW) {
155 			/* Allow writing to Nullify, Divide-step-correction,
156 			 * and carry/borrow bits.
157 			 * BEWARE, if you set N, and then single step, it won't
158 			 * stop on the nullified instruction.
159 			 */
160 			data &= USER_PSW_BITS;
161 			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
162 			task_regs(child)->gr[0] |= data;
163 			ret = 0;
164 			break;
165 		}
166 
167 		if ((addr & (sizeof(unsigned long)-1)) ||
168 		     addr >= sizeof(struct pt_regs))
169 			break;
170 		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
171 				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
172 				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
173 				addr == PT_SAR) {
174 			*(unsigned long *) ((char *) task_regs(child) + addr) = data;
175 			ret = 0;
176 		}
177 		break;
178 
179 	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
180 		return copy_regset_to_user(child,
181 					   task_user_regset_view(current),
182 					   REGSET_GENERAL,
183 					   0, sizeof(struct user_regs_struct),
184 					   datap);
185 
186 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
187 		return copy_regset_from_user(child,
188 					     task_user_regset_view(current),
189 					     REGSET_GENERAL,
190 					     0, sizeof(struct user_regs_struct),
191 					     datap);
192 
193 	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
194 		return copy_regset_to_user(child,
195 					   task_user_regset_view(current),
196 					   REGSET_FP,
197 					   0, sizeof(struct user_fp_struct),
198 					   datap);
199 
200 	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
201 		return copy_regset_from_user(child,
202 					     task_user_regset_view(current),
203 					     REGSET_FP,
204 					     0, sizeof(struct user_fp_struct),
205 					     datap);
206 
207 	default:
208 		ret = ptrace_request(child, request, addr, data);
209 		break;
210 	}
211 
212 	return ret;
213 }
214 
215 
216 #ifdef CONFIG_COMPAT
217 
218 /* This function is needed to translate 32 bit pt_regs offsets in to
219  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
220  * will request offset 12 if it wants gr3, but the lower 32 bits of
221  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
222  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
223  * except for the fp registers which (a) are 64 bits, and (b) follow
224  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
225  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
226  * being 64 bit in both cases.
227  */
228 
229 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
230 {
231 	if (offset < 0)
232 		return sizeof(struct pt_regs);
233 	else if (offset <= 32*4)	/* gr[0..31] */
234 		return offset * 2 + 4;
235 	else if (offset <= 32*4+32*8)	/* gr[0..31] + fr[0..31] */
236 		return offset + 32*4;
237 	else if (offset < sizeof(struct pt_regs)/2 + 32*4)
238 		return offset * 2 + 4 - 32*8;
239 	else
240 		return sizeof(struct pt_regs);
241 }
242 
243 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
244 			compat_ulong_t addr, compat_ulong_t data)
245 {
246 	compat_uint_t tmp;
247 	long ret = -EIO;
248 
249 	switch (request) {
250 
251 	case PTRACE_PEEKUSR:
252 		if (addr & (sizeof(compat_uint_t)-1))
253 			break;
254 		addr = translate_usr_offset(addr);
255 		if (addr >= sizeof(struct pt_regs))
256 			break;
257 
258 		tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
259 		ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
260 		break;
261 
262 	/* Write the word at location addr in the USER area.  This will need
263 	   to change when the kernel no longer saves all regs on a syscall.
264 	   FIXME.  There is a problem at the moment in that r3-r18 are only
265 	   saved if the process is ptraced on syscall entry, and even then
266 	   those values are overwritten by actual register values on syscall
267 	   exit. */
268 	case PTRACE_POKEUSR:
269 		/* Some register values written here may be ignored in
270 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
271 		 * r31/r31+4, and not with the values in pt_regs.
272 		 */
273 		if (addr == PT_PSW) {
274 			/* Since PT_PSW==0, it is valid for 32 bit processes
275 			 * under 64 bit kernels as well.
276 			 */
277 			ret = arch_ptrace(child, request, addr, data);
278 		} else {
279 			if (addr & (sizeof(compat_uint_t)-1))
280 				break;
281 			addr = translate_usr_offset(addr);
282 			if (addr >= sizeof(struct pt_regs))
283 				break;
284 			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
285 				/* Special case, fp regs are 64 bits anyway */
286 				*(__u64 *) ((char *) task_regs(child) + addr) = data;
287 				ret = 0;
288 			}
289 			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
290 					addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
291 					addr == PT_SAR+4) {
292 				/* Zero the top 32 bits */
293 				*(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
294 				*(__u32 *) ((char *) task_regs(child) + addr) = data;
295 				ret = 0;
296 			}
297 		}
298 		break;
299 
300 	default:
301 		ret = compat_ptrace_request(child, request, addr, data);
302 		break;
303 	}
304 
305 	return ret;
306 }
307 #endif
308 
309 long do_syscall_trace_enter(struct pt_regs *regs)
310 {
311 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
312 	    tracehook_report_syscall_entry(regs)) {
313 		/*
314 		 * Tracing decided this syscall should not happen or the
315 		 * debugger stored an invalid system call number. Skip
316 		 * the system call and the system call restart handling.
317 		 */
318 		regs->gr[20] = -1UL;
319 		goto out;
320 	}
321 
322 	/* Do the secure computing check after ptrace. */
323 	if (secure_computing(NULL) == -1)
324 		return -1;
325 
326 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
327 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
328 		trace_sys_enter(regs, regs->gr[20]);
329 #endif
330 
331 #ifdef CONFIG_64BIT
332 	if (!is_compat_task())
333 		audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
334 				    regs->gr[24], regs->gr[23]);
335 	else
336 #endif
337 		audit_syscall_entry(regs->gr[20] & 0xffffffff,
338 			regs->gr[26] & 0xffffffff,
339 			regs->gr[25] & 0xffffffff,
340 			regs->gr[24] & 0xffffffff,
341 			regs->gr[23] & 0xffffffff);
342 
343 out:
344 	/*
345 	 * Sign extend the syscall number to 64bit since it may have been
346 	 * modified by a compat ptrace call
347 	 */
348 	return (int) ((u32) regs->gr[20]);
349 }
350 
351 void do_syscall_trace_exit(struct pt_regs *regs)
352 {
353 	int stepping = test_thread_flag(TIF_SINGLESTEP) ||
354 		test_thread_flag(TIF_BLOCKSTEP);
355 
356 	audit_syscall_exit(regs);
357 
358 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
359 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
360 		trace_sys_exit(regs, regs->gr[20]);
361 #endif
362 
363 	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
364 		tracehook_report_syscall_exit(regs, stepping);
365 }
366 
367 
368 /*
369  * regset functions.
370  */
371 
372 static int fpr_get(struct task_struct *target,
373 		     const struct user_regset *regset,
374 		     unsigned int pos, unsigned int count,
375 		     void *kbuf, void __user *ubuf)
376 {
377 	struct pt_regs *regs = task_regs(target);
378 	__u64 *k = kbuf;
379 	__u64 __user *u = ubuf;
380 	__u64 reg;
381 
382 	pos /= sizeof(reg);
383 	count /= sizeof(reg);
384 
385 	if (kbuf)
386 		for (; count > 0 && pos < ELF_NFPREG; --count)
387 			*k++ = regs->fr[pos++];
388 	else
389 		for (; count > 0 && pos < ELF_NFPREG; --count)
390 			if (__put_user(regs->fr[pos++], u++))
391 				return -EFAULT;
392 
393 	kbuf = k;
394 	ubuf = u;
395 	pos *= sizeof(reg);
396 	count *= sizeof(reg);
397 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
398 					ELF_NFPREG * sizeof(reg), -1);
399 }
400 
401 static int fpr_set(struct task_struct *target,
402 		     const struct user_regset *regset,
403 		     unsigned int pos, unsigned int count,
404 		     const void *kbuf, const void __user *ubuf)
405 {
406 	struct pt_regs *regs = task_regs(target);
407 	const __u64 *k = kbuf;
408 	const __u64 __user *u = ubuf;
409 	__u64 reg;
410 
411 	pos /= sizeof(reg);
412 	count /= sizeof(reg);
413 
414 	if (kbuf)
415 		for (; count > 0 && pos < ELF_NFPREG; --count)
416 			regs->fr[pos++] = *k++;
417 	else
418 		for (; count > 0 && pos < ELF_NFPREG; --count) {
419 			if (__get_user(reg, u++))
420 				return -EFAULT;
421 			regs->fr[pos++] = reg;
422 		}
423 
424 	kbuf = k;
425 	ubuf = u;
426 	pos *= sizeof(reg);
427 	count *= sizeof(reg);
428 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
429 					 ELF_NFPREG * sizeof(reg), -1);
430 }
431 
432 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
433 
434 static unsigned long get_reg(struct pt_regs *regs, int num)
435 {
436 	switch (num) {
437 	case RI(gr[0]) ... RI(gr[31]):	return regs->gr[num - RI(gr[0])];
438 	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
439 	case RI(iasq[0]):		return regs->iasq[0];
440 	case RI(iasq[1]):		return regs->iasq[1];
441 	case RI(iaoq[0]):		return regs->iaoq[0];
442 	case RI(iaoq[1]):		return regs->iaoq[1];
443 	case RI(sar):			return regs->sar;
444 	case RI(iir):			return regs->iir;
445 	case RI(isr):			return regs->isr;
446 	case RI(ior):			return regs->ior;
447 	case RI(ipsw):			return regs->ipsw;
448 	case RI(cr27):			return regs->cr27;
449 	case RI(cr0):			return mfctl(0);
450 	case RI(cr24):			return mfctl(24);
451 	case RI(cr25):			return mfctl(25);
452 	case RI(cr26):			return mfctl(26);
453 	case RI(cr28):			return mfctl(28);
454 	case RI(cr29):			return mfctl(29);
455 	case RI(cr30):			return mfctl(30);
456 	case RI(cr31):			return mfctl(31);
457 	case RI(cr8):			return mfctl(8);
458 	case RI(cr9):			return mfctl(9);
459 	case RI(cr12):			return mfctl(12);
460 	case RI(cr13):			return mfctl(13);
461 	case RI(cr10):			return mfctl(10);
462 	case RI(cr15):			return mfctl(15);
463 	default:			return 0;
464 	}
465 }
466 
467 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
468 {
469 	switch (num) {
470 	case RI(gr[0]): /*
471 			 * PSW is in gr[0].
472 			 * Allow writing to Nullify, Divide-step-correction,
473 			 * and carry/borrow bits.
474 			 * BEWARE, if you set N, and then single step, it won't
475 			 * stop on the nullified instruction.
476 			 */
477 			val &= USER_PSW_BITS;
478 			regs->gr[0] &= ~USER_PSW_BITS;
479 			regs->gr[0] |= val;
480 			return;
481 	case RI(gr[1]) ... RI(gr[31]):
482 			regs->gr[num - RI(gr[0])] = val;
483 			return;
484 	case RI(iaoq[0]):
485 	case RI(iaoq[1]):
486 			regs->iaoq[num - RI(iaoq[0])] = val;
487 			return;
488 	case RI(sar):	regs->sar = val;
489 			return;
490 	default:	return;
491 #if 0
492 	/* do not allow to change any of the following registers (yet) */
493 	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
494 	case RI(iasq[0]):		return regs->iasq[0];
495 	case RI(iasq[1]):		return regs->iasq[1];
496 	case RI(iir):			return regs->iir;
497 	case RI(isr):			return regs->isr;
498 	case RI(ior):			return regs->ior;
499 	case RI(ipsw):			return regs->ipsw;
500 	case RI(cr27):			return regs->cr27;
501         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
502         case cr8, cr9, cr12, cr13, cr10, cr15;
503 #endif
504 	}
505 }
506 
507 static int gpr_get(struct task_struct *target,
508 		     const struct user_regset *regset,
509 		     unsigned int pos, unsigned int count,
510 		     void *kbuf, void __user *ubuf)
511 {
512 	struct pt_regs *regs = task_regs(target);
513 	unsigned long *k = kbuf;
514 	unsigned long __user *u = ubuf;
515 	unsigned long reg;
516 
517 	pos /= sizeof(reg);
518 	count /= sizeof(reg);
519 
520 	if (kbuf)
521 		for (; count > 0 && pos < ELF_NGREG; --count)
522 			*k++ = get_reg(regs, pos++);
523 	else
524 		for (; count > 0 && pos < ELF_NGREG; --count)
525 			if (__put_user(get_reg(regs, pos++), u++))
526 				return -EFAULT;
527 	kbuf = k;
528 	ubuf = u;
529 	pos *= sizeof(reg);
530 	count *= sizeof(reg);
531 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
532 					ELF_NGREG * sizeof(reg), -1);
533 }
534 
535 static int gpr_set(struct task_struct *target,
536 		     const struct user_regset *regset,
537 		     unsigned int pos, unsigned int count,
538 		     const void *kbuf, const void __user *ubuf)
539 {
540 	struct pt_regs *regs = task_regs(target);
541 	const unsigned long *k = kbuf;
542 	const unsigned long __user *u = ubuf;
543 	unsigned long reg;
544 
545 	pos /= sizeof(reg);
546 	count /= sizeof(reg);
547 
548 	if (kbuf)
549 		for (; count > 0 && pos < ELF_NGREG; --count)
550 			set_reg(regs, pos++, *k++);
551 	else
552 		for (; count > 0 && pos < ELF_NGREG; --count) {
553 			if (__get_user(reg, u++))
554 				return -EFAULT;
555 			set_reg(regs, pos++, reg);
556 		}
557 
558 	kbuf = k;
559 	ubuf = u;
560 	pos *= sizeof(reg);
561 	count *= sizeof(reg);
562 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
563 					 ELF_NGREG * sizeof(reg), -1);
564 }
565 
566 static const struct user_regset native_regsets[] = {
567 	[REGSET_GENERAL] = {
568 		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
569 		.size = sizeof(long), .align = sizeof(long),
570 		.get = gpr_get, .set = gpr_set
571 	},
572 	[REGSET_FP] = {
573 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
574 		.size = sizeof(__u64), .align = sizeof(__u64),
575 		.get = fpr_get, .set = fpr_set
576 	}
577 };
578 
579 static const struct user_regset_view user_parisc_native_view = {
580 	.name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
581 	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
582 };
583 
584 #ifdef CONFIG_64BIT
585 #include <linux/compat.h>
586 
587 static int gpr32_get(struct task_struct *target,
588 		     const struct user_regset *regset,
589 		     unsigned int pos, unsigned int count,
590 		     void *kbuf, void __user *ubuf)
591 {
592 	struct pt_regs *regs = task_regs(target);
593 	compat_ulong_t *k = kbuf;
594 	compat_ulong_t __user *u = ubuf;
595 	compat_ulong_t reg;
596 
597 	pos /= sizeof(reg);
598 	count /= sizeof(reg);
599 
600 	if (kbuf)
601 		for (; count > 0 && pos < ELF_NGREG; --count)
602 			*k++ = get_reg(regs, pos++);
603 	else
604 		for (; count > 0 && pos < ELF_NGREG; --count)
605 			if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
606 				return -EFAULT;
607 
608 	kbuf = k;
609 	ubuf = u;
610 	pos *= sizeof(reg);
611 	count *= sizeof(reg);
612 	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
613 					ELF_NGREG * sizeof(reg), -1);
614 }
615 
616 static int gpr32_set(struct task_struct *target,
617 		     const struct user_regset *regset,
618 		     unsigned int pos, unsigned int count,
619 		     const void *kbuf, const void __user *ubuf)
620 {
621 	struct pt_regs *regs = task_regs(target);
622 	const compat_ulong_t *k = kbuf;
623 	const compat_ulong_t __user *u = ubuf;
624 	compat_ulong_t reg;
625 
626 	pos /= sizeof(reg);
627 	count /= sizeof(reg);
628 
629 	if (kbuf)
630 		for (; count > 0 && pos < ELF_NGREG; --count)
631 			set_reg(regs, pos++, *k++);
632 	else
633 		for (; count > 0 && pos < ELF_NGREG; --count) {
634 			if (__get_user(reg, u++))
635 				return -EFAULT;
636 			set_reg(regs, pos++, reg);
637 		}
638 
639 	kbuf = k;
640 	ubuf = u;
641 	pos *= sizeof(reg);
642 	count *= sizeof(reg);
643 	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
644 					 ELF_NGREG * sizeof(reg), -1);
645 }
646 
647 /*
648  * These are the regset flavors matching the 32bit native set.
649  */
650 static const struct user_regset compat_regsets[] = {
651 	[REGSET_GENERAL] = {
652 		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
653 		.size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
654 		.get = gpr32_get, .set = gpr32_set
655 	},
656 	[REGSET_FP] = {
657 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
658 		.size = sizeof(__u64), .align = sizeof(__u64),
659 		.get = fpr_get, .set = fpr_set
660 	}
661 };
662 
663 static const struct user_regset_view user_parisc_compat_view = {
664 	.name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
665 	.regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
666 };
667 #endif	/* CONFIG_64BIT */
668 
669 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
670 {
671 	BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
672 	BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
673 #ifdef CONFIG_64BIT
674 	if (is_compat_task())
675 		return &user_parisc_compat_view;
676 #endif
677 	return &user_parisc_native_view;
678 }
679 
680 
681 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
682 
683 struct pt_regs_offset {
684 	const char *name;
685 	int offset;
686 };
687 
688 #define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
689 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
690 #define REG_OFFSET_END {.name = NULL, .offset = 0}
691 
692 static const struct pt_regs_offset regoffset_table[] = {
693 	REG_OFFSET_INDEX(gr,0),
694 	REG_OFFSET_INDEX(gr,1),
695 	REG_OFFSET_INDEX(gr,2),
696 	REG_OFFSET_INDEX(gr,3),
697 	REG_OFFSET_INDEX(gr,4),
698 	REG_OFFSET_INDEX(gr,5),
699 	REG_OFFSET_INDEX(gr,6),
700 	REG_OFFSET_INDEX(gr,7),
701 	REG_OFFSET_INDEX(gr,8),
702 	REG_OFFSET_INDEX(gr,9),
703 	REG_OFFSET_INDEX(gr,10),
704 	REG_OFFSET_INDEX(gr,11),
705 	REG_OFFSET_INDEX(gr,12),
706 	REG_OFFSET_INDEX(gr,13),
707 	REG_OFFSET_INDEX(gr,14),
708 	REG_OFFSET_INDEX(gr,15),
709 	REG_OFFSET_INDEX(gr,16),
710 	REG_OFFSET_INDEX(gr,17),
711 	REG_OFFSET_INDEX(gr,18),
712 	REG_OFFSET_INDEX(gr,19),
713 	REG_OFFSET_INDEX(gr,20),
714 	REG_OFFSET_INDEX(gr,21),
715 	REG_OFFSET_INDEX(gr,22),
716 	REG_OFFSET_INDEX(gr,23),
717 	REG_OFFSET_INDEX(gr,24),
718 	REG_OFFSET_INDEX(gr,25),
719 	REG_OFFSET_INDEX(gr,26),
720 	REG_OFFSET_INDEX(gr,27),
721 	REG_OFFSET_INDEX(gr,28),
722 	REG_OFFSET_INDEX(gr,29),
723 	REG_OFFSET_INDEX(gr,30),
724 	REG_OFFSET_INDEX(gr,31),
725 	REG_OFFSET_INDEX(sr,0),
726 	REG_OFFSET_INDEX(sr,1),
727 	REG_OFFSET_INDEX(sr,2),
728 	REG_OFFSET_INDEX(sr,3),
729 	REG_OFFSET_INDEX(sr,4),
730 	REG_OFFSET_INDEX(sr,5),
731 	REG_OFFSET_INDEX(sr,6),
732 	REG_OFFSET_INDEX(sr,7),
733 	REG_OFFSET_INDEX(iasq,0),
734 	REG_OFFSET_INDEX(iasq,1),
735 	REG_OFFSET_INDEX(iaoq,0),
736 	REG_OFFSET_INDEX(iaoq,1),
737 	REG_OFFSET_NAME(cr27),
738 	REG_OFFSET_NAME(ksp),
739 	REG_OFFSET_NAME(kpc),
740 	REG_OFFSET_NAME(sar),
741 	REG_OFFSET_NAME(iir),
742 	REG_OFFSET_NAME(isr),
743 	REG_OFFSET_NAME(ior),
744 	REG_OFFSET_NAME(ipsw),
745 	REG_OFFSET_END,
746 };
747 
748 /**
749  * regs_query_register_offset() - query register offset from its name
750  * @name:	the name of a register
751  *
752  * regs_query_register_offset() returns the offset of a register in struct
753  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
754  */
755 int regs_query_register_offset(const char *name)
756 {
757 	const struct pt_regs_offset *roff;
758 	for (roff = regoffset_table; roff->name != NULL; roff++)
759 		if (!strcmp(roff->name, name))
760 			return roff->offset;
761 	return -EINVAL;
762 }
763 
764 /**
765  * regs_query_register_name() - query register name from its offset
766  * @offset:	the offset of a register in struct pt_regs.
767  *
768  * regs_query_register_name() returns the name of a register from its
769  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
770  */
771 const char *regs_query_register_name(unsigned int offset)
772 {
773 	const struct pt_regs_offset *roff;
774 	for (roff = regoffset_table; roff->name != NULL; roff++)
775 		if (roff->offset == offset)
776 			return roff->name;
777 	return NULL;
778 }
779