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 */
40enum 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 */
50void ptrace_disable(struct task_struct *task)
51{
52 clear_tsk_thread_flag(tsk: task, TIF_SINGLESTEP);
53 clear_tsk_thread_flag(tsk: 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 */
66void user_disable_single_step(struct task_struct *task)
67{
68 ptrace_disable(task);
69}
70
71void user_enable_single_step(struct task_struct *task)
72{
73 clear_tsk_thread_flag(tsk: task, TIF_BLOCKSTEP);
74 set_tsk_thread_flag(tsk: 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 addr: (void __user *) (task_regs(task)->iaoq[0] & ~3),
91 t: 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
110void user_enable_block_step(struct task_struct *task)
111{
112 clear_tsk_thread_flag(tsk: task, TIF_SINGLESTEP);
113 set_tsk_thread_flag(tsk: 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
122long 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 unsigned long user_regs_struct_size = sizeof(struct user_regs_struct);
130#ifdef CONFIG_64BIT
131 if (is_compat_task())
132 user_regs_struct_size /= 2;
133#endif
134
135 switch (request) {
136
137 /* Read the word at location addr in the USER area. For ptraced
138 processes, the kernel saves all regs on a syscall. */
139 case PTRACE_PEEKUSR:
140 if ((addr & (sizeof(unsigned long)-1)) ||
141 addr >= sizeof(struct pt_regs))
142 break;
143 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
144 ret = put_user(tmp, datap);
145 break;
146
147 /* Write the word at location addr in the USER area. This will need
148 to change when the kernel no longer saves all regs on a syscall.
149 FIXME. There is a problem at the moment in that r3-r18 are only
150 saved if the process is ptraced on syscall entry, and even then
151 those values are overwritten by actual register values on syscall
152 exit. */
153 case PTRACE_POKEUSR:
154 /* Some register values written here may be ignored in
155 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
156 * r31/r31+4, and not with the values in pt_regs.
157 */
158 if (addr == PT_PSW) {
159 /* Allow writing to Nullify, Divide-step-correction,
160 * and carry/borrow bits.
161 * BEWARE, if you set N, and then single step, it won't
162 * stop on the nullified instruction.
163 */
164 data &= USER_PSW_BITS;
165 task_regs(child)->gr[0] &= ~USER_PSW_BITS;
166 task_regs(child)->gr[0] |= data;
167 ret = 0;
168 break;
169 }
170
171 if ((addr & (sizeof(unsigned long)-1)) ||
172 addr >= sizeof(struct pt_regs))
173 break;
174 if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
175 data |= PRIV_USER; /* ensure userspace privilege */
176 }
177 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
178 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
179 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
180 addr == PT_SAR) {
181 *(unsigned long *) ((char *) task_regs(child) + addr) = data;
182 ret = 0;
183 }
184 break;
185
186 case PTRACE_GETREGS: /* Get all gp regs from the child. */
187 return copy_regset_to_user(target: child,
188 view: task_user_regset_view(current),
189 setno: REGSET_GENERAL,
190 offset: 0, size: user_regs_struct_size,
191 data: datap);
192
193 case PTRACE_SETREGS: /* Set all gp regs in the child. */
194 return copy_regset_from_user(target: child,
195 view: task_user_regset_view(current),
196 setno: REGSET_GENERAL,
197 offset: 0, size: user_regs_struct_size,
198 data: datap);
199
200 case PTRACE_GETFPREGS: /* Get the child FPU state. */
201 return copy_regset_to_user(child,
202 task_user_regset_view(current),
203 REGSET_FP,
204 0, sizeof(struct user_fp_struct),
205 datap);
206
207 case PTRACE_SETFPREGS: /* Set the child FPU state. */
208 return copy_regset_from_user(child,
209 task_user_regset_view(current),
210 REGSET_FP,
211 0, sizeof(struct user_fp_struct),
212 datap);
213
214 default:
215 ret = ptrace_request(child, request, addr, data);
216 break;
217 }
218
219 return ret;
220}
221
222
223#ifdef CONFIG_COMPAT
224
225/* This function is needed to translate 32 bit pt_regs offsets in to
226 * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel
227 * will request offset 12 if it wants gr3, but the lower 32 bits of
228 * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
229 * This code relies on a 32 bit pt_regs being comprised of 32 bit values
230 * except for the fp registers which (a) are 64 bits, and (b) follow
231 * the gr registers at the start of pt_regs. The 32 bit pt_regs should
232 * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
233 * being 64 bit in both cases.
234 */
235
236static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
237{
238 compat_ulong_t pos;
239
240 if (offset < 32*4) /* gr[0..31] */
241 pos = offset * 2 + 4;
242 else if (offset < 32*4+32*8) /* fr[0] ... fr[31] */
243 pos = (offset - 32*4) + PT_FR0;
244 else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
245 pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
246 else
247 pos = sizeof(struct pt_regs);
248
249 return pos;
250}
251
252long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
253 compat_ulong_t addr, compat_ulong_t data)
254{
255 compat_uint_t tmp;
256 long ret = -EIO;
257
258 switch (request) {
259
260 case PTRACE_PEEKUSR:
261 if (addr & (sizeof(compat_uint_t)-1))
262 break;
263 addr = translate_usr_offset(offset: addr);
264 if (addr >= sizeof(struct pt_regs))
265 break;
266
267 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
268 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
269 break;
270
271 /* Write the word at location addr in the USER area. This will need
272 to change when the kernel no longer saves all regs on a syscall.
273 FIXME. There is a problem at the moment in that r3-r18 are only
274 saved if the process is ptraced on syscall entry, and even then
275 those values are overwritten by actual register values on syscall
276 exit. */
277 case PTRACE_POKEUSR:
278 /* Some register values written here may be ignored in
279 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
280 * r31/r31+4, and not with the values in pt_regs.
281 */
282 if (addr == PT_PSW) {
283 /* Since PT_PSW==0, it is valid for 32 bit processes
284 * under 64 bit kernels as well.
285 */
286 ret = arch_ptrace(child, request, addr, data);
287 } else {
288 if (addr & (sizeof(compat_uint_t)-1))
289 break;
290 addr = translate_usr_offset(offset: addr);
291 if (addr >= sizeof(struct pt_regs))
292 break;
293 if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
294 data |= PRIV_USER; /* ensure userspace privilege */
295 }
296 if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
297 /* Special case, fp regs are 64 bits anyway */
298 *(__u32 *) ((char *) task_regs(child) + addr) = data;
299 ret = 0;
300 }
301 else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
302 addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
303 addr == PT_SAR+4) {
304 /* Zero the top 32 bits */
305 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
306 *(__u32 *) ((char *) task_regs(child) + addr) = data;
307 ret = 0;
308 }
309 }
310 break;
311 case PTRACE_GETREGS:
312 case PTRACE_SETREGS:
313 case PTRACE_GETFPREGS:
314 case PTRACE_SETFPREGS:
315 return arch_ptrace(child, request, addr, data);
316
317 default:
318 ret = compat_ptrace_request(child, request, addr, data);
319 break;
320 }
321
322 return ret;
323}
324#endif
325
326long do_syscall_trace_enter(struct pt_regs *regs)
327{
328 if (test_thread_flag(TIF_SYSCALL_TRACE)) {
329 int rc = ptrace_report_syscall_entry(regs);
330
331 /*
332 * As tracesys_next does not set %r28 to -ENOSYS
333 * when %r20 is set to -1, initialize it here.
334 */
335 regs->gr[28] = -ENOSYS;
336
337 if (rc) {
338 /*
339 * A nonzero return code from
340 * ptrace_report_syscall_entry() tells us
341 * to prevent the syscall execution. Skip
342 * the syscall call and the syscall restart handling.
343 *
344 * Note that the tracer may also just change
345 * regs->gr[20] to an invalid syscall number,
346 * that is handled by tracesys_next.
347 */
348 regs->gr[20] = -1UL;
349 return -1;
350 }
351 }
352
353 /* Do the secure computing check after ptrace. */
354 if (secure_computing() == -1)
355 return -1;
356
357#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
358 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
359 trace_sys_enter(regs, id: regs->gr[20]);
360#endif
361
362#ifdef CONFIG_64BIT
363 if (!is_compat_task())
364 audit_syscall_entry(major: regs->gr[20], a0: regs->gr[26], a1: regs->gr[25],
365 a2: regs->gr[24], a3: regs->gr[23]);
366 else
367#endif
368 audit_syscall_entry(major: regs->gr[20] & 0xffffffff,
369 a0: regs->gr[26] & 0xffffffff,
370 a1: regs->gr[25] & 0xffffffff,
371 a2: regs->gr[24] & 0xffffffff,
372 a3: regs->gr[23] & 0xffffffff);
373
374 /*
375 * Sign extend the syscall number to 64bit since it may have been
376 * modified by a compat ptrace call
377 */
378 return (int) ((u32) regs->gr[20]);
379}
380
381void do_syscall_trace_exit(struct pt_regs *regs)
382{
383 int stepping = test_thread_flag(TIF_SINGLESTEP) ||
384 test_thread_flag(TIF_BLOCKSTEP);
385
386 audit_syscall_exit(pt_regs: regs);
387
388#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
389 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
390 trace_sys_exit(regs, ret: regs->gr[20]);
391#endif
392
393 if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
394 ptrace_report_syscall_exit(regs, step: stepping);
395}
396
397
398/*
399 * regset functions.
400 */
401
402static int fpr_get(struct task_struct *target,
403 const struct user_regset *regset,
404 struct membuf to)
405{
406 struct pt_regs *regs = task_regs(target);
407
408 return membuf_write(&to, regs->fr, ELF_NFPREG * sizeof(__u64));
409}
410
411static int fpr_set(struct task_struct *target,
412 const struct user_regset *regset,
413 unsigned int pos, unsigned int count,
414 const void *kbuf, const void __user *ubuf)
415{
416 struct pt_regs *regs = task_regs(target);
417 const __u64 *k = kbuf;
418 const __u64 __user *u = ubuf;
419 __u64 reg;
420
421 pos /= sizeof(reg);
422 count /= sizeof(reg);
423
424 if (kbuf)
425 for (; count > 0 && pos < ELF_NFPREG; --count)
426 regs->fr[pos++] = *k++;
427 else
428 for (; count > 0 && pos < ELF_NFPREG; --count) {
429 if (__get_user(reg, u++))
430 return -EFAULT;
431 regs->fr[pos++] = reg;
432 }
433
434 kbuf = k;
435 ubuf = u;
436 pos *= sizeof(reg);
437 count *= sizeof(reg);
438 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
439 ELF_NFPREG * sizeof(reg), -1);
440 return 0;
441}
442
443#define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
444
445static unsigned long get_reg(struct pt_regs *regs, int num)
446{
447 switch (num) {
448 case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])];
449 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
450 case RI(iasq[0]): return regs->iasq[0];
451 case RI(iasq[1]): return regs->iasq[1];
452 case RI(iaoq[0]): return regs->iaoq[0];
453 case RI(iaoq[1]): return regs->iaoq[1];
454 case RI(sar): return regs->sar;
455 case RI(iir): return regs->iir;
456 case RI(isr): return regs->isr;
457 case RI(ior): return regs->ior;
458 case RI(ipsw): return regs->ipsw;
459 case RI(cr27): return regs->cr27;
460 case RI(cr0): return mfctl(0);
461 case RI(cr24): return mfctl(24);
462 case RI(cr25): return mfctl(25);
463 case RI(cr26): return mfctl(26);
464 case RI(cr28): return mfctl(28);
465 case RI(cr29): return mfctl(29);
466 case RI(cr30): return mfctl(30);
467 case RI(cr31): return mfctl(31);
468 case RI(cr8): return mfctl(8);
469 case RI(cr9): return mfctl(9);
470 case RI(cr12): return mfctl(12);
471 case RI(cr13): return mfctl(13);
472 case RI(cr10): return mfctl(10);
473 case RI(cr15): return mfctl(15);
474 default: return 0;
475 }
476}
477
478static void set_reg(struct pt_regs *regs, int num, unsigned long val)
479{
480 switch (num) {
481 case RI(gr[0]): /*
482 * PSW is in gr[0].
483 * Allow writing to Nullify, Divide-step-correction,
484 * and carry/borrow bits.
485 * BEWARE, if you set N, and then single step, it won't
486 * stop on the nullified instruction.
487 */
488 val &= USER_PSW_BITS;
489 regs->gr[0] &= ~USER_PSW_BITS;
490 regs->gr[0] |= val;
491 return;
492 case RI(gr[1]) ... RI(gr[31]):
493 regs->gr[num - RI(gr[0])] = val;
494 return;
495 case RI(iaoq[0]):
496 case RI(iaoq[1]):
497 /* set 2 lowest bits to ensure userspace privilege: */
498 regs->iaoq[num - RI(iaoq[0])] = val | PRIV_USER;
499 return;
500 case RI(sar): regs->sar = val;
501 return;
502 default: return;
503#if 0
504 /* do not allow to change any of the following registers (yet) */
505 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
506 case RI(iasq[0]): return regs->iasq[0];
507 case RI(iasq[1]): return regs->iasq[1];
508 case RI(iir): return regs->iir;
509 case RI(isr): return regs->isr;
510 case RI(ior): return regs->ior;
511 case RI(ipsw): return regs->ipsw;
512 case RI(cr27): return regs->cr27;
513 case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
514 case cr8, cr9, cr12, cr13, cr10, cr15;
515#endif
516 }
517}
518
519static int gpr_get(struct task_struct *target,
520 const struct user_regset *regset,
521 struct membuf to)
522{
523 struct pt_regs *regs = task_regs(target);
524 unsigned int pos;
525
526 for (pos = 0; pos < ELF_NGREG; pos++)
527 membuf_store(&to, get_reg(regs, pos));
528 return 0;
529}
530
531static int gpr_set(struct task_struct *target,
532 const struct user_regset *regset,
533 unsigned int pos, unsigned int count,
534 const void *kbuf, const void __user *ubuf)
535{
536 struct pt_regs *regs = task_regs(target);
537 const unsigned long *k = kbuf;
538 const unsigned long __user *u = ubuf;
539 unsigned long reg;
540
541 pos /= sizeof(reg);
542 count /= sizeof(reg);
543
544 if (kbuf)
545 for (; count > 0 && pos < ELF_NGREG; --count)
546 set_reg(regs, num: pos++, val: *k++);
547 else
548 for (; count > 0 && pos < ELF_NGREG; --count) {
549 if (__get_user(reg, u++))
550 return -EFAULT;
551 set_reg(regs, num: pos++, val: reg);
552 }
553
554 kbuf = k;
555 ubuf = u;
556 pos *= sizeof(reg);
557 count *= sizeof(reg);
558 user_regset_copyin_ignore(pos: &pos, count: &count, kbuf: &kbuf, ubuf: &ubuf,
559 ELF_NGREG * sizeof(reg), end_pos: -1);
560 return 0;
561}
562
563static const struct user_regset native_regsets[] = {
564 [REGSET_GENERAL] = {
565 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
566 .size = sizeof(long), .align = sizeof(long),
567 .regset_get = gpr_get, .set = gpr_set
568 },
569 [REGSET_FP] = {
570 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
571 .size = sizeof(__u64), .align = sizeof(__u64),
572 .regset_get = fpr_get, .set = fpr_set
573 }
574};
575
576static const struct user_regset_view user_parisc_native_view = {
577 .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
578 .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
579};
580
581#ifdef CONFIG_64BIT
582static int gpr32_get(struct task_struct *target,
583 const struct user_regset *regset,
584 struct membuf to)
585{
586 struct pt_regs *regs = task_regs(target);
587 unsigned int pos;
588
589 for (pos = 0; pos < ELF_NGREG; pos++)
590 membuf_store(&to, (compat_ulong_t)get_reg(regs, pos));
591
592 return 0;
593}
594
595static int gpr32_set(struct task_struct *target,
596 const struct user_regset *regset,
597 unsigned int pos, unsigned int count,
598 const void *kbuf, const void __user *ubuf)
599{
600 struct pt_regs *regs = task_regs(target);
601 const compat_ulong_t *k = kbuf;
602 const compat_ulong_t __user *u = ubuf;
603 compat_ulong_t reg;
604
605 pos /= sizeof(reg);
606 count /= sizeof(reg);
607
608 if (kbuf)
609 for (; count > 0 && pos < ELF_NGREG; --count)
610 set_reg(regs, num: pos++, val: *k++);
611 else
612 for (; count > 0 && pos < ELF_NGREG; --count) {
613 if (__get_user(reg, u++))
614 return -EFAULT;
615 set_reg(regs, num: pos++, val: reg);
616 }
617
618 kbuf = k;
619 ubuf = u;
620 pos *= sizeof(reg);
621 count *= sizeof(reg);
622 user_regset_copyin_ignore(pos: &pos, count: &count, kbuf: &kbuf, ubuf: &ubuf,
623 ELF_NGREG * sizeof(reg), end_pos: -1);
624 return 0;
625}
626
627/*
628 * These are the regset flavors matching the 32bit native set.
629 */
630static const struct user_regset compat_regsets[] = {
631 [REGSET_GENERAL] = {
632 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
633 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
634 .regset_get = gpr32_get, .set = gpr32_set
635 },
636 [REGSET_FP] = {
637 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
638 .size = sizeof(__u64), .align = sizeof(__u64),
639 .regset_get = fpr_get, .set = fpr_set
640 }
641};
642
643static const struct user_regset_view user_parisc_compat_view = {
644 .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
645 .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
646};
647#endif /* CONFIG_64BIT */
648
649const struct user_regset_view *task_user_regset_view(struct task_struct *task)
650{
651 BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
652 BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
653#ifdef CONFIG_64BIT
654 if (is_compat_task())
655 return &user_parisc_compat_view;
656#endif
657 return &user_parisc_native_view;
658}
659
660
661/* HAVE_REGS_AND_STACK_ACCESS_API feature */
662
663struct pt_regs_offset {
664 const char *name;
665 int offset;
666};
667
668#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
669#define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
670#define REG_OFFSET_END {.name = NULL, .offset = 0}
671
672static const struct pt_regs_offset regoffset_table[] = {
673 REG_OFFSET_INDEX(gr,0),
674 REG_OFFSET_INDEX(gr,1),
675 REG_OFFSET_INDEX(gr,2),
676 REG_OFFSET_INDEX(gr,3),
677 REG_OFFSET_INDEX(gr,4),
678 REG_OFFSET_INDEX(gr,5),
679 REG_OFFSET_INDEX(gr,6),
680 REG_OFFSET_INDEX(gr,7),
681 REG_OFFSET_INDEX(gr,8),
682 REG_OFFSET_INDEX(gr,9),
683 REG_OFFSET_INDEX(gr,10),
684 REG_OFFSET_INDEX(gr,11),
685 REG_OFFSET_INDEX(gr,12),
686 REG_OFFSET_INDEX(gr,13),
687 REG_OFFSET_INDEX(gr,14),
688 REG_OFFSET_INDEX(gr,15),
689 REG_OFFSET_INDEX(gr,16),
690 REG_OFFSET_INDEX(gr,17),
691 REG_OFFSET_INDEX(gr,18),
692 REG_OFFSET_INDEX(gr,19),
693 REG_OFFSET_INDEX(gr,20),
694 REG_OFFSET_INDEX(gr,21),
695 REG_OFFSET_INDEX(gr,22),
696 REG_OFFSET_INDEX(gr,23),
697 REG_OFFSET_INDEX(gr,24),
698 REG_OFFSET_INDEX(gr,25),
699 REG_OFFSET_INDEX(gr,26),
700 REG_OFFSET_INDEX(gr,27),
701 REG_OFFSET_INDEX(gr,28),
702 REG_OFFSET_INDEX(gr,29),
703 REG_OFFSET_INDEX(gr,30),
704 REG_OFFSET_INDEX(gr,31),
705 REG_OFFSET_INDEX(sr,0),
706 REG_OFFSET_INDEX(sr,1),
707 REG_OFFSET_INDEX(sr,2),
708 REG_OFFSET_INDEX(sr,3),
709 REG_OFFSET_INDEX(sr,4),
710 REG_OFFSET_INDEX(sr,5),
711 REG_OFFSET_INDEX(sr,6),
712 REG_OFFSET_INDEX(sr,7),
713 REG_OFFSET_INDEX(iasq,0),
714 REG_OFFSET_INDEX(iasq,1),
715 REG_OFFSET_INDEX(iaoq,0),
716 REG_OFFSET_INDEX(iaoq,1),
717 REG_OFFSET_NAME(cr27),
718 REG_OFFSET_NAME(ksp),
719 REG_OFFSET_NAME(kpc),
720 REG_OFFSET_NAME(sar),
721 REG_OFFSET_NAME(iir),
722 REG_OFFSET_NAME(isr),
723 REG_OFFSET_NAME(ior),
724 REG_OFFSET_NAME(ipsw),
725 REG_OFFSET_END,
726};
727
728/**
729 * regs_query_register_offset() - query register offset from its name
730 * @name: the name of a register
731 *
732 * regs_query_register_offset() returns the offset of a register in struct
733 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
734 */
735int regs_query_register_offset(const char *name)
736{
737 const struct pt_regs_offset *roff;
738 for (roff = regoffset_table; roff->name != NULL; roff++)
739 if (!strcmp(roff->name, name))
740 return roff->offset;
741 return -EINVAL;
742}
743
744/**
745 * regs_query_register_name() - query register name from its offset
746 * @offset: the offset of a register in struct pt_regs.
747 *
748 * regs_query_register_name() returns the name of a register from its
749 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
750 */
751const char *regs_query_register_name(unsigned int offset)
752{
753 const struct pt_regs_offset *roff;
754 for (roff = regoffset_table; roff->name != NULL; roff++)
755 if (roff->offset == offset)
756 return roff->name;
757 return NULL;
758}
759
760/**
761 * regs_within_kernel_stack() - check the address in the stack
762 * @regs: pt_regs which contains kernel stack pointer.
763 * @addr: address which is checked.
764 *
765 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
766 * If @addr is within the kernel stack, it returns true. If not, returns false.
767 */
768int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
769{
770 return ((addr & ~(THREAD_SIZE - 1)) ==
771 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
772}
773
774/**
775 * regs_get_kernel_stack_nth() - get Nth entry of the stack
776 * @regs: pt_regs which contains kernel stack pointer.
777 * @n: stack entry number.
778 *
779 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
780 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
781 * this returns 0.
782 */
783unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
784{
785 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
786
787 addr -= n;
788
789 if (!regs_within_kernel_stack(regs, (unsigned long)addr))
790 return 0;
791
792 return *addr;
793}
794

source code of linux/arch/parisc/kernel/ptrace.c