xref: /openbmc/linux/arch/parisc/kernel/ptrace.c (revision aaa746ad)
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/user.h>
19 #include <linux/personality.h>
20 #include <linux/regset.h>
21 #include <linux/security.h>
22 #include <linux/seccomp.h>
23 #include <linux/compat.h>
24 #include <linux/signal.h>
25 #include <linux/audit.h>
26 
27 #include <linux/uaccess.h>
28 #include <asm/processor.h>
29 #include <asm/asm-offsets.h>
30 
31 /* PSW bits we allow the debugger to modify */
32 #define USER_PSW_BITS	(PSW_N | PSW_B | PSW_V | PSW_CB)
33 
34 #define CREATE_TRACE_POINTS
35 #include <trace/events/syscalls.h>
36 
37 /*
38  * These are our native regset flavors.
39  */
40 enum parisc_regset {
41 	REGSET_GENERAL,
42 	REGSET_FP
43 };
44 
45 /*
46  * Called by kernel/ptrace.c when detaching..
47  *
48  * Make sure single step bits etc are not set.
49  */
50 void ptrace_disable(struct task_struct *task)
51 {
52 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
53 	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
54 
55 	/* make sure the trap bits are not set */
56 	pa_psw(task)->r = 0;
57 	pa_psw(task)->t = 0;
58 	pa_psw(task)->h = 0;
59 	pa_psw(task)->l = 0;
60 }
61 
62 /*
63  * The following functions are called by ptrace_resume() when
64  * enabling or disabling single/block tracing.
65  */
66 void user_disable_single_step(struct task_struct *task)
67 {
68 	ptrace_disable(task);
69 }
70 
71 void user_enable_single_step(struct task_struct *task)
72 {
73 	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
74 	set_tsk_thread_flag(task, TIF_SINGLESTEP);
75 
76 	if (pa_psw(task)->n) {
77 		/* Nullified, just crank over the queue. */
78 		task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
79 		task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
80 		task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
81 		pa_psw(task)->n = 0;
82 		pa_psw(task)->x = 0;
83 		pa_psw(task)->y = 0;
84 		pa_psw(task)->z = 0;
85 		pa_psw(task)->b = 0;
86 		ptrace_disable(task);
87 		/* Don't wake up the task, but let the
88 		   parent know something happened. */
89 		force_sig_fault_to_task(SIGTRAP, TRAP_TRACE,
90 					(void __user *) (task_regs(task)->iaoq[0] & ~3),
91 					task);
92 		/* notify_parent(task, SIGCHLD); */
93 		return;
94 	}
95 
96 	/* Enable recovery counter traps.  The recovery counter
97 	 * itself will be set to zero on a task switch.  If the
98 	 * task is suspended on a syscall then the syscall return
99 	 * path will overwrite the recovery counter with a suitable
100 	 * value such that it traps once back in user space.  We
101 	 * disable interrupts in the tasks PSW here also, to avoid
102 	 * interrupts while the recovery counter is decrementing.
103 	 */
104 	pa_psw(task)->r = 1;
105 	pa_psw(task)->t = 0;
106 	pa_psw(task)->h = 0;
107 	pa_psw(task)->l = 0;
108 }
109 
110 void user_enable_block_step(struct task_struct *task)
111 {
112 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
113 	set_tsk_thread_flag(task, TIF_BLOCKSTEP);
114 
115 	/* Enable taken branch trap. */
116 	pa_psw(task)->r = 0;
117 	pa_psw(task)->t = 1;
118 	pa_psw(task)->h = 0;
119 	pa_psw(task)->l = 0;
120 }
121 
122 long arch_ptrace(struct task_struct *child, long request,
123 		 unsigned long addr, unsigned long data)
124 {
125 	unsigned long __user *datap = (unsigned long __user *)data;
126 	unsigned long tmp;
127 	long ret = -EIO;
128 
129 	switch (request) {
130 
131 	/* Read the word at location addr in the USER area.  For ptraced
132 	   processes, the kernel saves all regs on a syscall. */
133 	case PTRACE_PEEKUSR:
134 		if ((addr & (sizeof(unsigned long)-1)) ||
135 		     addr >= sizeof(struct pt_regs))
136 			break;
137 		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
138 		ret = put_user(tmp, datap);
139 		break;
140 
141 	/* Write the word at location addr in the USER area.  This will need
142 	   to change when the kernel no longer saves all regs on a syscall.
143 	   FIXME.  There is a problem at the moment in that r3-r18 are only
144 	   saved if the process is ptraced on syscall entry, and even then
145 	   those values are overwritten by actual register values on syscall
146 	   exit. */
147 	case PTRACE_POKEUSR:
148 		/* Some register values written here may be ignored in
149 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
150 		 * r31/r31+4, and not with the values in pt_regs.
151 		 */
152 		if (addr == PT_PSW) {
153 			/* Allow writing to Nullify, Divide-step-correction,
154 			 * and carry/borrow bits.
155 			 * BEWARE, if you set N, and then single step, it won't
156 			 * stop on the nullified instruction.
157 			 */
158 			data &= USER_PSW_BITS;
159 			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
160 			task_regs(child)->gr[0] |= data;
161 			ret = 0;
162 			break;
163 		}
164 
165 		if ((addr & (sizeof(unsigned long)-1)) ||
166 		     addr >= sizeof(struct pt_regs))
167 			break;
168 		if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
169 			data |= 3; /* ensure userspace privilege */
170 		}
171 		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
172 				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
173 				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
174 				addr == PT_SAR) {
175 			*(unsigned long *) ((char *) task_regs(child) + addr) = data;
176 			ret = 0;
177 		}
178 		break;
179 
180 	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
181 		return copy_regset_to_user(child,
182 					   task_user_regset_view(current),
183 					   REGSET_GENERAL,
184 					   0, sizeof(struct user_regs_struct),
185 					   datap);
186 
187 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
188 		return copy_regset_from_user(child,
189 					     task_user_regset_view(current),
190 					     REGSET_GENERAL,
191 					     0, sizeof(struct user_regs_struct),
192 					     datap);
193 
194 	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
195 		return copy_regset_to_user(child,
196 					   task_user_regset_view(current),
197 					   REGSET_FP,
198 					   0, sizeof(struct user_fp_struct),
199 					   datap);
200 
201 	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
202 		return copy_regset_from_user(child,
203 					     task_user_regset_view(current),
204 					     REGSET_FP,
205 					     0, sizeof(struct user_fp_struct),
206 					     datap);
207 
208 	default:
209 		ret = ptrace_request(child, request, addr, data);
210 		break;
211 	}
212 
213 	return ret;
214 }
215 
216 
217 #ifdef CONFIG_COMPAT
218 
219 /* This function is needed to translate 32 bit pt_regs offsets in to
220  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
221  * will request offset 12 if it wants gr3, but the lower 32 bits of
222  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
223  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
224  * except for the fp registers which (a) are 64 bits, and (b) follow
225  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
226  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
227  * being 64 bit in both cases.
228  */
229 
230 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
231 {
232 	compat_ulong_t pos;
233 
234 	if (offset < 32*4)	/* gr[0..31] */
235 		pos = offset * 2 + 4;
236 	else if (offset < 32*4+32*8)	/* fr[0] ... fr[31] */
237 		pos = (offset - 32*4) + PT_FR0;
238 	else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
239 		pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
240 	else
241 		pos = sizeof(struct pt_regs);
242 
243 	return pos;
244 }
245 
246 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
247 			compat_ulong_t addr, compat_ulong_t data)
248 {
249 	compat_uint_t tmp;
250 	long ret = -EIO;
251 
252 	switch (request) {
253 
254 	case PTRACE_PEEKUSR:
255 		if (addr & (sizeof(compat_uint_t)-1))
256 			break;
257 		addr = translate_usr_offset(addr);
258 		if (addr >= sizeof(struct pt_regs))
259 			break;
260 
261 		tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
262 		ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
263 		break;
264 
265 	/* Write the word at location addr in the USER area.  This will need
266 	   to change when the kernel no longer saves all regs on a syscall.
267 	   FIXME.  There is a problem at the moment in that r3-r18 are only
268 	   saved if the process is ptraced on syscall entry, and even then
269 	   those values are overwritten by actual register values on syscall
270 	   exit. */
271 	case PTRACE_POKEUSR:
272 		/* Some register values written here may be ignored in
273 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
274 		 * r31/r31+4, and not with the values in pt_regs.
275 		 */
276 		if (addr == PT_PSW) {
277 			/* Since PT_PSW==0, it is valid for 32 bit processes
278 			 * under 64 bit kernels as well.
279 			 */
280 			ret = arch_ptrace(child, request, addr, data);
281 		} else {
282 			if (addr & (sizeof(compat_uint_t)-1))
283 				break;
284 			addr = translate_usr_offset(addr);
285 			if (addr >= sizeof(struct pt_regs))
286 				break;
287 			if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
288 				data |= 3; /* ensure userspace privilege */
289 			}
290 			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
291 				/* Special case, fp regs are 64 bits anyway */
292 				*(__u32 *) ((char *) task_regs(child) + addr) = data;
293 				ret = 0;
294 			}
295 			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
296 					addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
297 					addr == PT_SAR+4) {
298 				/* Zero the top 32 bits */
299 				*(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
300 				*(__u32 *) ((char *) task_regs(child) + addr) = data;
301 				ret = 0;
302 			}
303 		}
304 		break;
305 
306 	default:
307 		ret = compat_ptrace_request(child, request, addr, data);
308 		break;
309 	}
310 
311 	return ret;
312 }
313 #endif
314 
315 long do_syscall_trace_enter(struct pt_regs *regs)
316 {
317 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
318 		int rc = ptrace_report_syscall_entry(regs);
319 
320 		/*
321 		 * As tracesys_next does not set %r28 to -ENOSYS
322 		 * when %r20 is set to -1, initialize it here.
323 		 */
324 		regs->gr[28] = -ENOSYS;
325 
326 		if (rc) {
327 			/*
328 			 * A nonzero return code from
329 			 * ptrace_report_syscall_entry() tells us
330 			 * to prevent the syscall execution.  Skip
331 			 * the syscall call and the syscall restart handling.
332 			 *
333 			 * Note that the tracer may also just change
334 			 * regs->gr[20] to an invalid syscall number,
335 			 * that is handled by tracesys_next.
336 			 */
337 			regs->gr[20] = -1UL;
338 			return -1;
339 		}
340 	}
341 
342 	/* Do the secure computing check after ptrace. */
343 	if (secure_computing() == -1)
344 		return -1;
345 
346 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
347 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
348 		trace_sys_enter(regs, regs->gr[20]);
349 #endif
350 
351 #ifdef CONFIG_64BIT
352 	if (!is_compat_task())
353 		audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
354 				    regs->gr[24], regs->gr[23]);
355 	else
356 #endif
357 		audit_syscall_entry(regs->gr[20] & 0xffffffff,
358 			regs->gr[26] & 0xffffffff,
359 			regs->gr[25] & 0xffffffff,
360 			regs->gr[24] & 0xffffffff,
361 			regs->gr[23] & 0xffffffff);
362 
363 	/*
364 	 * Sign extend the syscall number to 64bit since it may have been
365 	 * modified by a compat ptrace call
366 	 */
367 	return (int) ((u32) regs->gr[20]);
368 }
369 
370 void do_syscall_trace_exit(struct pt_regs *regs)
371 {
372 	int stepping = test_thread_flag(TIF_SINGLESTEP) ||
373 		test_thread_flag(TIF_BLOCKSTEP);
374 
375 	audit_syscall_exit(regs);
376 
377 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
378 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
379 		trace_sys_exit(regs, regs->gr[20]);
380 #endif
381 
382 	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
383 		ptrace_report_syscall_exit(regs, stepping);
384 }
385 
386 
387 /*
388  * regset functions.
389  */
390 
391 static int fpr_get(struct task_struct *target,
392 		     const struct user_regset *regset,
393 		     struct membuf to)
394 {
395 	struct pt_regs *regs = task_regs(target);
396 
397 	return membuf_write(&to, regs->fr, ELF_NFPREG * sizeof(__u64));
398 }
399 
400 static int fpr_set(struct task_struct *target,
401 		     const struct user_regset *regset,
402 		     unsigned int pos, unsigned int count,
403 		     const void *kbuf, const void __user *ubuf)
404 {
405 	struct pt_regs *regs = task_regs(target);
406 	const __u64 *k = kbuf;
407 	const __u64 __user *u = ubuf;
408 	__u64 reg;
409 
410 	pos /= sizeof(reg);
411 	count /= sizeof(reg);
412 
413 	if (kbuf)
414 		for (; count > 0 && pos < ELF_NFPREG; --count)
415 			regs->fr[pos++] = *k++;
416 	else
417 		for (; count > 0 && pos < ELF_NFPREG; --count) {
418 			if (__get_user(reg, u++))
419 				return -EFAULT;
420 			regs->fr[pos++] = reg;
421 		}
422 
423 	kbuf = k;
424 	ubuf = u;
425 	pos *= sizeof(reg);
426 	count *= sizeof(reg);
427 	user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
428 				  ELF_NFPREG * sizeof(reg), -1);
429 	return 0;
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 			/* set 2 lowest bits to ensure userspace privilege: */
487 			regs->iaoq[num - RI(iaoq[0])] = val | 3;
488 			return;
489 	case RI(sar):	regs->sar = val;
490 			return;
491 	default:	return;
492 #if 0
493 	/* do not allow to change any of the following registers (yet) */
494 	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
495 	case RI(iasq[0]):		return regs->iasq[0];
496 	case RI(iasq[1]):		return regs->iasq[1];
497 	case RI(iir):			return regs->iir;
498 	case RI(isr):			return regs->isr;
499 	case RI(ior):			return regs->ior;
500 	case RI(ipsw):			return regs->ipsw;
501 	case RI(cr27):			return regs->cr27;
502         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
503         case cr8, cr9, cr12, cr13, cr10, cr15;
504 #endif
505 	}
506 }
507 
508 static int gpr_get(struct task_struct *target,
509 		     const struct user_regset *regset,
510 		     struct membuf to)
511 {
512 	struct pt_regs *regs = task_regs(target);
513 	unsigned int pos;
514 
515 	for (pos = 0; pos < ELF_NGREG; pos++)
516 		membuf_store(&to, get_reg(regs, pos));
517 	return 0;
518 }
519 
520 static int gpr_set(struct task_struct *target,
521 		     const struct user_regset *regset,
522 		     unsigned int pos, unsigned int count,
523 		     const void *kbuf, const void __user *ubuf)
524 {
525 	struct pt_regs *regs = task_regs(target);
526 	const unsigned long *k = kbuf;
527 	const unsigned long __user *u = ubuf;
528 	unsigned long reg;
529 
530 	pos /= sizeof(reg);
531 	count /= sizeof(reg);
532 
533 	if (kbuf)
534 		for (; count > 0 && pos < ELF_NGREG; --count)
535 			set_reg(regs, pos++, *k++);
536 	else
537 		for (; count > 0 && pos < ELF_NGREG; --count) {
538 			if (__get_user(reg, u++))
539 				return -EFAULT;
540 			set_reg(regs, pos++, reg);
541 		}
542 
543 	kbuf = k;
544 	ubuf = u;
545 	pos *= sizeof(reg);
546 	count *= sizeof(reg);
547 	user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
548 				  ELF_NGREG * sizeof(reg), -1);
549 	return 0;
550 }
551 
552 static const struct user_regset native_regsets[] = {
553 	[REGSET_GENERAL] = {
554 		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
555 		.size = sizeof(long), .align = sizeof(long),
556 		.regset_get = gpr_get, .set = gpr_set
557 	},
558 	[REGSET_FP] = {
559 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
560 		.size = sizeof(__u64), .align = sizeof(__u64),
561 		.regset_get = fpr_get, .set = fpr_set
562 	}
563 };
564 
565 static const struct user_regset_view user_parisc_native_view = {
566 	.name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
567 	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
568 };
569 
570 #ifdef CONFIG_64BIT
571 static int gpr32_get(struct task_struct *target,
572 		     const struct user_regset *regset,
573 		     struct membuf to)
574 {
575 	struct pt_regs *regs = task_regs(target);
576 	unsigned int pos;
577 
578 	for (pos = 0; pos < ELF_NGREG; pos++)
579 		membuf_store(&to, (compat_ulong_t)get_reg(regs, pos));
580 
581 	return 0;
582 }
583 
584 static int gpr32_set(struct task_struct *target,
585 		     const struct user_regset *regset,
586 		     unsigned int pos, unsigned int count,
587 		     const void *kbuf, const void __user *ubuf)
588 {
589 	struct pt_regs *regs = task_regs(target);
590 	const compat_ulong_t *k = kbuf;
591 	const compat_ulong_t __user *u = ubuf;
592 	compat_ulong_t reg;
593 
594 	pos /= sizeof(reg);
595 	count /= sizeof(reg);
596 
597 	if (kbuf)
598 		for (; count > 0 && pos < ELF_NGREG; --count)
599 			set_reg(regs, pos++, *k++);
600 	else
601 		for (; count > 0 && pos < ELF_NGREG; --count) {
602 			if (__get_user(reg, u++))
603 				return -EFAULT;
604 			set_reg(regs, pos++, reg);
605 		}
606 
607 	kbuf = k;
608 	ubuf = u;
609 	pos *= sizeof(reg);
610 	count *= sizeof(reg);
611 	user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
612 				  ELF_NGREG * sizeof(reg), -1);
613 	return 0;
614 }
615 
616 /*
617  * These are the regset flavors matching the 32bit native set.
618  */
619 static const struct user_regset compat_regsets[] = {
620 	[REGSET_GENERAL] = {
621 		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
622 		.size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
623 		.regset_get = gpr32_get, .set = gpr32_set
624 	},
625 	[REGSET_FP] = {
626 		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
627 		.size = sizeof(__u64), .align = sizeof(__u64),
628 		.regset_get = fpr_get, .set = fpr_set
629 	}
630 };
631 
632 static const struct user_regset_view user_parisc_compat_view = {
633 	.name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
634 	.regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
635 };
636 #endif	/* CONFIG_64BIT */
637 
638 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
639 {
640 	BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
641 	BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
642 #ifdef CONFIG_64BIT
643 	if (is_compat_task())
644 		return &user_parisc_compat_view;
645 #endif
646 	return &user_parisc_native_view;
647 }
648 
649 
650 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
651 
652 struct pt_regs_offset {
653 	const char *name;
654 	int offset;
655 };
656 
657 #define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
658 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
659 #define REG_OFFSET_END {.name = NULL, .offset = 0}
660 
661 static const struct pt_regs_offset regoffset_table[] = {
662 	REG_OFFSET_INDEX(gr,0),
663 	REG_OFFSET_INDEX(gr,1),
664 	REG_OFFSET_INDEX(gr,2),
665 	REG_OFFSET_INDEX(gr,3),
666 	REG_OFFSET_INDEX(gr,4),
667 	REG_OFFSET_INDEX(gr,5),
668 	REG_OFFSET_INDEX(gr,6),
669 	REG_OFFSET_INDEX(gr,7),
670 	REG_OFFSET_INDEX(gr,8),
671 	REG_OFFSET_INDEX(gr,9),
672 	REG_OFFSET_INDEX(gr,10),
673 	REG_OFFSET_INDEX(gr,11),
674 	REG_OFFSET_INDEX(gr,12),
675 	REG_OFFSET_INDEX(gr,13),
676 	REG_OFFSET_INDEX(gr,14),
677 	REG_OFFSET_INDEX(gr,15),
678 	REG_OFFSET_INDEX(gr,16),
679 	REG_OFFSET_INDEX(gr,17),
680 	REG_OFFSET_INDEX(gr,18),
681 	REG_OFFSET_INDEX(gr,19),
682 	REG_OFFSET_INDEX(gr,20),
683 	REG_OFFSET_INDEX(gr,21),
684 	REG_OFFSET_INDEX(gr,22),
685 	REG_OFFSET_INDEX(gr,23),
686 	REG_OFFSET_INDEX(gr,24),
687 	REG_OFFSET_INDEX(gr,25),
688 	REG_OFFSET_INDEX(gr,26),
689 	REG_OFFSET_INDEX(gr,27),
690 	REG_OFFSET_INDEX(gr,28),
691 	REG_OFFSET_INDEX(gr,29),
692 	REG_OFFSET_INDEX(gr,30),
693 	REG_OFFSET_INDEX(gr,31),
694 	REG_OFFSET_INDEX(sr,0),
695 	REG_OFFSET_INDEX(sr,1),
696 	REG_OFFSET_INDEX(sr,2),
697 	REG_OFFSET_INDEX(sr,3),
698 	REG_OFFSET_INDEX(sr,4),
699 	REG_OFFSET_INDEX(sr,5),
700 	REG_OFFSET_INDEX(sr,6),
701 	REG_OFFSET_INDEX(sr,7),
702 	REG_OFFSET_INDEX(iasq,0),
703 	REG_OFFSET_INDEX(iasq,1),
704 	REG_OFFSET_INDEX(iaoq,0),
705 	REG_OFFSET_INDEX(iaoq,1),
706 	REG_OFFSET_NAME(cr27),
707 	REG_OFFSET_NAME(ksp),
708 	REG_OFFSET_NAME(kpc),
709 	REG_OFFSET_NAME(sar),
710 	REG_OFFSET_NAME(iir),
711 	REG_OFFSET_NAME(isr),
712 	REG_OFFSET_NAME(ior),
713 	REG_OFFSET_NAME(ipsw),
714 	REG_OFFSET_END,
715 };
716 
717 /**
718  * regs_query_register_offset() - query register offset from its name
719  * @name:	the name of a register
720  *
721  * regs_query_register_offset() returns the offset of a register in struct
722  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
723  */
724 int regs_query_register_offset(const char *name)
725 {
726 	const struct pt_regs_offset *roff;
727 	for (roff = regoffset_table; roff->name != NULL; roff++)
728 		if (!strcmp(roff->name, name))
729 			return roff->offset;
730 	return -EINVAL;
731 }
732 
733 /**
734  * regs_query_register_name() - query register name from its offset
735  * @offset:	the offset of a register in struct pt_regs.
736  *
737  * regs_query_register_name() returns the name of a register from its
738  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
739  */
740 const char *regs_query_register_name(unsigned int offset)
741 {
742 	const struct pt_regs_offset *roff;
743 	for (roff = regoffset_table; roff->name != NULL; roff++)
744 		if (roff->offset == offset)
745 			return roff->name;
746 	return NULL;
747 }
748 
749 /**
750  * regs_within_kernel_stack() - check the address in the stack
751  * @regs:      pt_regs which contains kernel stack pointer.
752  * @addr:      address which is checked.
753  *
754  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
755  * If @addr is within the kernel stack, it returns true. If not, returns false.
756  */
757 int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
758 {
759 	return ((addr & ~(THREAD_SIZE - 1))  ==
760 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
761 }
762 
763 /**
764  * regs_get_kernel_stack_nth() - get Nth entry of the stack
765  * @regs:	pt_regs which contains kernel stack pointer.
766  * @n:		stack entry number.
767  *
768  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
769  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
770  * this returns 0.
771  */
772 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
773 {
774 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
775 
776 	addr -= n;
777 
778 	if (!regs_within_kernel_stack(regs, (unsigned long)addr))
779 		return 0;
780 
781 	return *addr;
782 }
783