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1/* ptrace.c: Sparc process tracing support.
2 *
3 * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5 *
6 * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
7 * and David Mosberger.
8 *
9 * Added Linux support -miguel (weird, eh?, the original code was meant
10 * to emulate SunOS).
11 */
12
13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/mm.h>
16#include <linux/errno.h>
17#include <linux/ptrace.h>
18#include <linux/user.h>
19#include <linux/smp.h>
20#include <linux/security.h>
21#include <linux/seccomp.h>
22#include <linux/audit.h>
23#include <linux/signal.h>
24#include <linux/regset.h>
25#include <linux/tracehook.h>
26#include <trace/syscall.h>
27#include <linux/compat.h>
28#include <linux/elf.h>
29
30#include <asm/asi.h>
31#include <asm/pgtable.h>
32#include <asm/system.h>
33#include <asm/uaccess.h>
34#include <asm/psrcompat.h>
35#include <asm/visasm.h>
36#include <asm/spitfire.h>
37#include <asm/page.h>
38#include <asm/cpudata.h>
39#include <asm/cacheflush.h>
40
41#define CREATE_TRACE_POINTS
42#include <trace/events/syscalls.h>
43
44#include "entry.h"
45
46/* #define ALLOW_INIT_TRACING */
47
48/*
49 * Called by kernel/ptrace.c when detaching..
50 *
51 * Make sure single step bits etc are not set.
52 */
53void ptrace_disable(struct task_struct *child)
54{
55 /* nothing to do */
56}
57
58/* To get the necessary page struct, access_process_vm() first calls
59 * get_user_pages(). This has done a flush_dcache_page() on the
60 * accessed page. Then our caller (copy_{to,from}_user_page()) did
61 * to memcpy to read/write the data from that page.
62 *
63 * Now, the only thing we have to do is:
64 * 1) flush the D-cache if it's possible than an illegal alias
65 * has been created
66 * 2) flush the I-cache if this is pre-cheetah and we did a write
67 */
68void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
69 unsigned long uaddr, void *kaddr,
70 unsigned long len, int write)
71{
72 BUG_ON(len > PAGE_SIZE);
73
74 if (tlb_type == hypervisor)
75 return;
76
77 preempt_disable();
78
79#ifdef DCACHE_ALIASING_POSSIBLE
80 /* If bit 13 of the kernel address we used to access the
81 * user page is the same as the virtual address that page
82 * is mapped to in the user's address space, we can skip the
83 * D-cache flush.
84 */
85 if ((uaddr ^ (unsigned long) kaddr) & (1UL << 13)) {
86 unsigned long start = __pa(kaddr);
87 unsigned long end = start + len;
88 unsigned long dcache_line_size;
89
90 dcache_line_size = local_cpu_data().dcache_line_size;
91
92 if (tlb_type == spitfire) {
93 for (; start < end; start += dcache_line_size)
94 spitfire_put_dcache_tag(start & 0x3fe0, 0x0);
95 } else {
96 start &= ~(dcache_line_size - 1);
97 for (; start < end; start += dcache_line_size)
98 __asm__ __volatile__(
99 "stxa %%g0, [%0] %1\n\t"
100 "membar #Sync"
101 : /* no outputs */
102 : "r" (start),
103 "i" (ASI_DCACHE_INVALIDATE));
104 }
105 }
106#endif
107 if (write && tlb_type == spitfire) {
108 unsigned long start = (unsigned long) kaddr;
109 unsigned long end = start + len;
110 unsigned long icache_line_size;
111
112 icache_line_size = local_cpu_data().icache_line_size;
113
114 for (; start < end; start += icache_line_size)
115 flushi(start);
116 }
117
118 preempt_enable();
119}
120
121static int get_from_target(struct task_struct *target, unsigned long uaddr,
122 void *kbuf, int len)
123{
124 if (target == current) {
125 if (copy_from_user(kbuf, (void __user *) uaddr, len))
126 return -EFAULT;
127 } else {
128 int len2 = access_process_vm(target, uaddr, kbuf, len, 0);
129 if (len2 != len)
130 return -EFAULT;
131 }
132 return 0;
133}
134
135static int set_to_target(struct task_struct *target, unsigned long uaddr,
136 void *kbuf, int len)
137{
138 if (target == current) {
139 if (copy_to_user((void __user *) uaddr, kbuf, len))
140 return -EFAULT;
141 } else {
142 int len2 = access_process_vm(target, uaddr, kbuf, len, 1);
143 if (len2 != len)
144 return -EFAULT;
145 }
146 return 0;
147}
148
149static int regwindow64_get(struct task_struct *target,
150 const struct pt_regs *regs,
151 struct reg_window *wbuf)
152{
153 unsigned long rw_addr = regs->u_regs[UREG_I6];
154
155 if (test_tsk_thread_flag(current, TIF_32BIT)) {
156 struct reg_window32 win32;
157 int i;
158
159 if (get_from_target(target, rw_addr, &win32, sizeof(win32)))
160 return -EFAULT;
161 for (i = 0; i < 8; i++)
162 wbuf->locals[i] = win32.locals[i];
163 for (i = 0; i < 8; i++)
164 wbuf->ins[i] = win32.ins[i];
165 } else {
166 rw_addr += STACK_BIAS;
167 if (get_from_target(target, rw_addr, wbuf, sizeof(*wbuf)))
168 return -EFAULT;
169 }
170
171 return 0;
172}
173
174static int regwindow64_set(struct task_struct *target,
175 const struct pt_regs *regs,
176 struct reg_window *wbuf)
177{
178 unsigned long rw_addr = regs->u_regs[UREG_I6];
179
180 if (test_tsk_thread_flag(current, TIF_32BIT)) {
181 struct reg_window32 win32;
182 int i;
183
184 for (i = 0; i < 8; i++)
185 win32.locals[i] = wbuf->locals[i];
186 for (i = 0; i < 8; i++)
187 win32.ins[i] = wbuf->ins[i];
188
189 if (set_to_target(target, rw_addr, &win32, sizeof(win32)))
190 return -EFAULT;
191 } else {
192 rw_addr += STACK_BIAS;
193 if (set_to_target(target, rw_addr, wbuf, sizeof(*wbuf)))
194 return -EFAULT;
195 }
196
197 return 0;
198}
199
200enum sparc_regset {
201 REGSET_GENERAL,
202 REGSET_FP,
203};
204
205static int genregs64_get(struct task_struct *target,
206 const struct user_regset *regset,
207 unsigned int pos, unsigned int count,
208 void *kbuf, void __user *ubuf)
209{
210 const struct pt_regs *regs = task_pt_regs(target);
211 int ret;
212
213 if (target == current)
214 flushw_user();
215
216 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
217 regs->u_regs,
218 0, 16 * sizeof(u64));
219 if (!ret && count && pos < (32 * sizeof(u64))) {
220 struct reg_window window;
221
222 if (regwindow64_get(target, regs, &window))
223 return -EFAULT;
224 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
225 &window,
226 16 * sizeof(u64),
227 32 * sizeof(u64));
228 }
229
230 if (!ret) {
231 /* TSTATE, TPC, TNPC */
232 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
233 ®s->tstate,
234 32 * sizeof(u64),
235 35 * sizeof(u64));
236 }
237
238 if (!ret) {
239 unsigned long y = regs->y;
240
241 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
242 &y,
243 35 * sizeof(u64),
244 36 * sizeof(u64));
245 }
246
247 if (!ret) {
248 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
249 36 * sizeof(u64), -1);
250
251 }
252 return ret;
253}
254
255static int genregs64_set(struct task_struct *target,
256 const struct user_regset *regset,
257 unsigned int pos, unsigned int count,
258 const void *kbuf, const void __user *ubuf)
259{
260 struct pt_regs *regs = task_pt_regs(target);
261 int ret;
262
263 if (target == current)
264 flushw_user();
265
266 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
267 regs->u_regs,
268 0, 16 * sizeof(u64));
269 if (!ret && count && pos < (32 * sizeof(u64))) {
270 struct reg_window window;
271
272 if (regwindow64_get(target, regs, &window))
273 return -EFAULT;
274
275 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
276 &window,
277 16 * sizeof(u64),
278 32 * sizeof(u64));
279
280 if (!ret &&
281 regwindow64_set(target, regs, &window))
282 return -EFAULT;
283 }
284
285 if (!ret && count > 0) {
286 unsigned long tstate;
287
288 /* TSTATE */
289 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
290 &tstate,
291 32 * sizeof(u64),
292 33 * sizeof(u64));
293 if (!ret) {
294 /* Only the condition codes and the "in syscall"
295 * state can be modified in the %tstate register.
296 */
297 tstate &= (TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
298 regs->tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
299 regs->tstate |= tstate;
300 }
301 }
302
303 if (!ret) {
304 /* TPC, TNPC */
305 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
306 ®s->tpc,
307 33 * sizeof(u64),
308 35 * sizeof(u64));
309 }
310
311 if (!ret) {
312 unsigned long y;
313
314 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
315 &y,
316 35 * sizeof(u64),
317 36 * sizeof(u64));
318 if (!ret)
319 regs->y = y;
320 }
321
322 if (!ret)
323 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
324 36 * sizeof(u64), -1);
325
326 return ret;
327}
328
329static int fpregs64_get(struct task_struct *target,
330 const struct user_regset *regset,
331 unsigned int pos, unsigned int count,
332 void *kbuf, void __user *ubuf)
333{
334 const unsigned long *fpregs = task_thread_info(target)->fpregs;
335 unsigned long fprs, fsr, gsr;
336 int ret;
337
338 if (target == current)
339 save_and_clear_fpu();
340
341 fprs = task_thread_info(target)->fpsaved[0];
342
343 if (fprs & FPRS_DL)
344 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
345 fpregs,
346 0, 16 * sizeof(u64));
347 else
348 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
349 0,
350 16 * sizeof(u64));
351
352 if (!ret) {
353 if (fprs & FPRS_DU)
354 ret = user_regset_copyout(&pos, &count,
355 &kbuf, &ubuf,
356 fpregs + 16,
357 16 * sizeof(u64),
358 32 * sizeof(u64));
359 else
360 ret = user_regset_copyout_zero(&pos, &count,
361 &kbuf, &ubuf,
362 16 * sizeof(u64),
363 32 * sizeof(u64));
364 }
365
366 if (fprs & FPRS_FEF) {
367 fsr = task_thread_info(target)->xfsr[0];
368 gsr = task_thread_info(target)->gsr[0];
369 } else {
370 fsr = gsr = 0;
371 }
372
373 if (!ret)
374 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
375 &fsr,
376 32 * sizeof(u64),
377 33 * sizeof(u64));
378 if (!ret)
379 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
380 &gsr,
381 33 * sizeof(u64),
382 34 * sizeof(u64));
383 if (!ret)
384 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
385 &fprs,
386 34 * sizeof(u64),
387 35 * sizeof(u64));
388
389 if (!ret)
390 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
391 35 * sizeof(u64), -1);
392
393 return ret;
394}
395
396static int fpregs64_set(struct task_struct *target,
397 const struct user_regset *regset,
398 unsigned int pos, unsigned int count,
399 const void *kbuf, const void __user *ubuf)
400{
401 unsigned long *fpregs = task_thread_info(target)->fpregs;
402 unsigned long fprs;
403 int ret;
404
405 if (target == current)
406 save_and_clear_fpu();
407
408 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
409 fpregs,
410 0, 32 * sizeof(u64));
411 if (!ret)
412 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
413 task_thread_info(target)->xfsr,
414 32 * sizeof(u64),
415 33 * sizeof(u64));
416 if (!ret)
417 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
418 task_thread_info(target)->gsr,
419 33 * sizeof(u64),
420 34 * sizeof(u64));
421
422 fprs = task_thread_info(target)->fpsaved[0];
423 if (!ret && count > 0) {
424 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
425 &fprs,
426 34 * sizeof(u64),
427 35 * sizeof(u64));
428 }
429
430 fprs |= (FPRS_FEF | FPRS_DL | FPRS_DU);
431 task_thread_info(target)->fpsaved[0] = fprs;
432
433 if (!ret)
434 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
435 35 * sizeof(u64), -1);
436 return ret;
437}
438
439static const struct user_regset sparc64_regsets[] = {
440 /* Format is:
441 * G0 --> G7
442 * O0 --> O7
443 * L0 --> L7
444 * I0 --> I7
445 * TSTATE, TPC, TNPC, Y
446 */
447 [REGSET_GENERAL] = {
448 .core_note_type = NT_PRSTATUS,
449 .n = 36,
450 .size = sizeof(u64), .align = sizeof(u64),
451 .get = genregs64_get, .set = genregs64_set
452 },
453 /* Format is:
454 * F0 --> F63
455 * FSR
456 * GSR
457 * FPRS
458 */
459 [REGSET_FP] = {
460 .core_note_type = NT_PRFPREG,
461 .n = 35,
462 .size = sizeof(u64), .align = sizeof(u64),
463 .get = fpregs64_get, .set = fpregs64_set
464 },
465};
466
467static const struct user_regset_view user_sparc64_view = {
468 .name = "sparc64", .e_machine = EM_SPARCV9,
469 .regsets = sparc64_regsets, .n = ARRAY_SIZE(sparc64_regsets)
470};
471
472#ifdef CONFIG_COMPAT
473static int genregs32_get(struct task_struct *target,
474 const struct user_regset *regset,
475 unsigned int pos, unsigned int count,
476 void *kbuf, void __user *ubuf)
477{
478 const struct pt_regs *regs = task_pt_regs(target);
479 compat_ulong_t __user *reg_window;
480 compat_ulong_t *k = kbuf;
481 compat_ulong_t __user *u = ubuf;
482 compat_ulong_t reg;
483
484 if (target == current)
485 flushw_user();
486
487 pos /= sizeof(reg);
488 count /= sizeof(reg);
489
490 if (kbuf) {
491 for (; count > 0 && pos < 16; count--)
492 *k++ = regs->u_regs[pos++];
493
494 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
495 reg_window -= 16;
496 if (target == current) {
497 for (; count > 0 && pos < 32; count--) {
498 if (get_user(*k++, ®_window[pos++]))
499 return -EFAULT;
500 }
501 } else {
502 for (; count > 0 && pos < 32; count--) {
503 if (access_process_vm(target,
504 (unsigned long)
505 ®_window[pos],
506 k, sizeof(*k), 0)
507 != sizeof(*k))
508 return -EFAULT;
509 k++;
510 pos++;
511 }
512 }
513 } else {
514 for (; count > 0 && pos < 16; count--) {
515 if (put_user((compat_ulong_t) regs->u_regs[pos++], u++))
516 return -EFAULT;
517 }
518
519 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
520 reg_window -= 16;
521 if (target == current) {
522 for (; count > 0 && pos < 32; count--) {
523 if (get_user(reg, ®_window[pos++]) ||
524 put_user(reg, u++))
525 return -EFAULT;
526 }
527 } else {
528 for (; count > 0 && pos < 32; count--) {
529 if (access_process_vm(target,
530 (unsigned long)
531 ®_window[pos],
532 ®, sizeof(reg), 0)
533 != sizeof(reg))
534 return -EFAULT;
535 if (access_process_vm(target,
536 (unsigned long) u,
537 ®, sizeof(reg), 1)
538 != sizeof(reg))
539 return -EFAULT;
540 pos++;
541 u++;
542 }
543 }
544 }
545 while (count > 0) {
546 switch (pos) {
547 case 32: /* PSR */
548 reg = tstate_to_psr(regs->tstate);
549 break;
550 case 33: /* PC */
551 reg = regs->tpc;
552 break;
553 case 34: /* NPC */
554 reg = regs->tnpc;
555 break;
556 case 35: /* Y */
557 reg = regs->y;
558 break;
559 case 36: /* WIM */
560 case 37: /* TBR */
561 reg = 0;
562 break;
563 default:
564 goto finish;
565 }
566
567 if (kbuf)
568 *k++ = reg;
569 else if (put_user(reg, u++))
570 return -EFAULT;
571 pos++;
572 count--;
573 }
574finish:
575 pos *= sizeof(reg);
576 count *= sizeof(reg);
577
578 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
579 38 * sizeof(reg), -1);
580}
581
582static int genregs32_set(struct task_struct *target,
583 const struct user_regset *regset,
584 unsigned int pos, unsigned int count,
585 const void *kbuf, const void __user *ubuf)
586{
587 struct pt_regs *regs = task_pt_regs(target);
588 compat_ulong_t __user *reg_window;
589 const compat_ulong_t *k = kbuf;
590 const compat_ulong_t __user *u = ubuf;
591 compat_ulong_t reg;
592
593 if (target == current)
594 flushw_user();
595
596 pos /= sizeof(reg);
597 count /= sizeof(reg);
598
599 if (kbuf) {
600 for (; count > 0 && pos < 16; count--)
601 regs->u_regs[pos++] = *k++;
602
603 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
604 reg_window -= 16;
605 if (target == current) {
606 for (; count > 0 && pos < 32; count--) {
607 if (put_user(*k++, ®_window[pos++]))
608 return -EFAULT;
609 }
610 } else {
611 for (; count > 0 && pos < 32; count--) {
612 if (access_process_vm(target,
613 (unsigned long)
614 ®_window[pos],
615 (void *) k,
616 sizeof(*k), 1)
617 != sizeof(*k))
618 return -EFAULT;
619 k++;
620 pos++;
621 }
622 }
623 } else {
624 for (; count > 0 && pos < 16; count--) {
625 if (get_user(reg, u++))
626 return -EFAULT;
627 regs->u_regs[pos++] = reg;
628 }
629
630 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
631 reg_window -= 16;
632 if (target == current) {
633 for (; count > 0 && pos < 32; count--) {
634 if (get_user(reg, u++) ||
635 put_user(reg, ®_window[pos++]))
636 return -EFAULT;
637 }
638 } else {
639 for (; count > 0 && pos < 32; count--) {
640 if (access_process_vm(target,
641 (unsigned long)
642 u,
643 ®, sizeof(reg), 0)
644 != sizeof(reg))
645 return -EFAULT;
646 if (access_process_vm(target,
647 (unsigned long)
648 ®_window[pos],
649 ®, sizeof(reg), 1)
650 != sizeof(reg))
651 return -EFAULT;
652 pos++;
653 u++;
654 }
655 }
656 }
657 while (count > 0) {
658 unsigned long tstate;
659
660 if (kbuf)
661 reg = *k++;
662 else if (get_user(reg, u++))
663 return -EFAULT;
664
665 switch (pos) {
666 case 32: /* PSR */
667 tstate = regs->tstate;
668 tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
669 tstate |= psr_to_tstate_icc(reg);
670 if (reg & PSR_SYSCALL)
671 tstate |= TSTATE_SYSCALL;
672 regs->tstate = tstate;
673 break;
674 case 33: /* PC */
675 regs->tpc = reg;
676 break;
677 case 34: /* NPC */
678 regs->tnpc = reg;
679 break;
680 case 35: /* Y */
681 regs->y = reg;
682 break;
683 case 36: /* WIM */
684 case 37: /* TBR */
685 break;
686 default:
687 goto finish;
688 }
689
690 pos++;
691 count--;
692 }
693finish:
694 pos *= sizeof(reg);
695 count *= sizeof(reg);
696
697 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
698 38 * sizeof(reg), -1);
699}
700
701static int fpregs32_get(struct task_struct *target,
702 const struct user_regset *regset,
703 unsigned int pos, unsigned int count,
704 void *kbuf, void __user *ubuf)
705{
706 const unsigned long *fpregs = task_thread_info(target)->fpregs;
707 compat_ulong_t enabled;
708 unsigned long fprs;
709 compat_ulong_t fsr;
710 int ret = 0;
711
712 if (target == current)
713 save_and_clear_fpu();
714
715 fprs = task_thread_info(target)->fpsaved[0];
716 if (fprs & FPRS_FEF) {
717 fsr = task_thread_info(target)->xfsr[0];
718 enabled = 1;
719 } else {
720 fsr = 0;
721 enabled = 0;
722 }
723
724 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
725 fpregs,
726 0, 32 * sizeof(u32));
727
728 if (!ret)
729 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
730 32 * sizeof(u32),
731 33 * sizeof(u32));
732 if (!ret)
733 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
734 &fsr,
735 33 * sizeof(u32),
736 34 * sizeof(u32));
737
738 if (!ret) {
739 compat_ulong_t val;
740
741 val = (enabled << 8) | (8 << 16);
742 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
743 &val,
744 34 * sizeof(u32),
745 35 * sizeof(u32));
746 }
747
748 if (!ret)
749 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
750 35 * sizeof(u32), -1);
751
752 return ret;
753}
754
755static int fpregs32_set(struct task_struct *target,
756 const struct user_regset *regset,
757 unsigned int pos, unsigned int count,
758 const void *kbuf, const void __user *ubuf)
759{
760 unsigned long *fpregs = task_thread_info(target)->fpregs;
761 unsigned long fprs;
762 int ret;
763
764 if (target == current)
765 save_and_clear_fpu();
766
767 fprs = task_thread_info(target)->fpsaved[0];
768
769 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
770 fpregs,
771 0, 32 * sizeof(u32));
772 if (!ret)
773 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
774 32 * sizeof(u32),
775 33 * sizeof(u32));
776 if (!ret && count > 0) {
777 compat_ulong_t fsr;
778 unsigned long val;
779
780 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
781 &fsr,
782 33 * sizeof(u32),
783 34 * sizeof(u32));
784 if (!ret) {
785 val = task_thread_info(target)->xfsr[0];
786 val &= 0xffffffff00000000UL;
787 val |= fsr;
788 task_thread_info(target)->xfsr[0] = val;
789 }
790 }
791
792 fprs |= (FPRS_FEF | FPRS_DL);
793 task_thread_info(target)->fpsaved[0] = fprs;
794
795 if (!ret)
796 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
797 34 * sizeof(u32), -1);
798 return ret;
799}
800
801static const struct user_regset sparc32_regsets[] = {
802 /* Format is:
803 * G0 --> G7
804 * O0 --> O7
805 * L0 --> L7
806 * I0 --> I7
807 * PSR, PC, nPC, Y, WIM, TBR
808 */
809 [REGSET_GENERAL] = {
810 .core_note_type = NT_PRSTATUS,
811 .n = 38,
812 .size = sizeof(u32), .align = sizeof(u32),
813 .get = genregs32_get, .set = genregs32_set
814 },
815 /* Format is:
816 * F0 --> F31
817 * empty 32-bit word
818 * FSR (32--bit word)
819 * FPU QUEUE COUNT (8-bit char)
820 * FPU QUEUE ENTRYSIZE (8-bit char)
821 * FPU ENABLED (8-bit char)
822 * empty 8-bit char
823 * FPU QUEUE (64 32-bit ints)
824 */
825 [REGSET_FP] = {
826 .core_note_type = NT_PRFPREG,
827 .n = 99,
828 .size = sizeof(u32), .align = sizeof(u32),
829 .get = fpregs32_get, .set = fpregs32_set
830 },
831};
832
833static const struct user_regset_view user_sparc32_view = {
834 .name = "sparc", .e_machine = EM_SPARC,
835 .regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
836};
837#endif /* CONFIG_COMPAT */
838
839const struct user_regset_view *task_user_regset_view(struct task_struct *task)
840{
841#ifdef CONFIG_COMPAT
842 if (test_tsk_thread_flag(task, TIF_32BIT))
843 return &user_sparc32_view;
844#endif
845 return &user_sparc64_view;
846}
847
848#ifdef CONFIG_COMPAT
849struct compat_fps {
850 unsigned int regs[32];
851 unsigned int fsr;
852 unsigned int flags;
853 unsigned int extra;
854 unsigned int fpqd;
855 struct compat_fq {
856 unsigned int insnaddr;
857 unsigned int insn;
858 } fpq[16];
859};
860
861long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
862 compat_ulong_t caddr, compat_ulong_t cdata)
863{
864 const struct user_regset_view *view = task_user_regset_view(current);
865 compat_ulong_t caddr2 = task_pt_regs(current)->u_regs[UREG_I4];
866 struct pt_regs32 __user *pregs;
867 struct compat_fps __user *fps;
868 unsigned long addr2 = caddr2;
869 unsigned long addr = caddr;
870 unsigned long data = cdata;
871 int ret;
872
873 pregs = (struct pt_regs32 __user *) addr;
874 fps = (struct compat_fps __user *) addr;
875
876 switch (request) {
877 case PTRACE_PEEKUSR:
878 ret = (addr != 0) ? -EIO : 0;
879 break;
880
881 case PTRACE_GETREGS:
882 ret = copy_regset_to_user(child, view, REGSET_GENERAL,
883 32 * sizeof(u32),
884 4 * sizeof(u32),
885 &pregs->psr);
886 if (!ret)
887 ret = copy_regset_to_user(child, view, REGSET_GENERAL,
888 1 * sizeof(u32),
889 15 * sizeof(u32),
890 &pregs->u_regs[0]);
891 break;
892
893 case PTRACE_SETREGS:
894 ret = copy_regset_from_user(child, view, REGSET_GENERAL,
895 32 * sizeof(u32),
896 4 * sizeof(u32),
897 &pregs->psr);
898 if (!ret)
899 ret = copy_regset_from_user(child, view, REGSET_GENERAL,
900 1 * sizeof(u32),
901 15 * sizeof(u32),
902 &pregs->u_regs[0]);
903 break;
904
905 case PTRACE_GETFPREGS:
906 ret = copy_regset_to_user(child, view, REGSET_FP,
907 0 * sizeof(u32),
908 32 * sizeof(u32),
909 &fps->regs[0]);
910 if (!ret)
911 ret = copy_regset_to_user(child, view, REGSET_FP,
912 33 * sizeof(u32),
913 1 * sizeof(u32),
914 &fps->fsr);
915 if (!ret) {
916 if (__put_user(0, &fps->flags) ||
917 __put_user(0, &fps->extra) ||
918 __put_user(0, &fps->fpqd) ||
919 clear_user(&fps->fpq[0], 32 * sizeof(unsigned int)))
920 ret = -EFAULT;
921 }
922 break;
923
924 case PTRACE_SETFPREGS:
925 ret = copy_regset_from_user(child, view, REGSET_FP,
926 0 * sizeof(u32),
927 32 * sizeof(u32),
928 &fps->regs[0]);
929 if (!ret)
930 ret = copy_regset_from_user(child, view, REGSET_FP,
931 33 * sizeof(u32),
932 1 * sizeof(u32),
933 &fps->fsr);
934 break;
935
936 case PTRACE_READTEXT:
937 case PTRACE_READDATA:
938 ret = ptrace_readdata(child, addr,
939 (char __user *)addr2, data);
940 if (ret == data)
941 ret = 0;
942 else if (ret >= 0)
943 ret = -EIO;
944 break;
945
946 case PTRACE_WRITETEXT:
947 case PTRACE_WRITEDATA:
948 ret = ptrace_writedata(child, (char __user *) addr2,
949 addr, data);
950 if (ret == data)
951 ret = 0;
952 else if (ret >= 0)
953 ret = -EIO;
954 break;
955
956 default:
957 if (request == PTRACE_SPARC_DETACH)
958 request = PTRACE_DETACH;
959 ret = compat_ptrace_request(child, request, addr, data);
960 break;
961 }
962
963 return ret;
964}
965#endif /* CONFIG_COMPAT */
966
967struct fps {
968 unsigned int regs[64];
969 unsigned long fsr;
970};
971
972long arch_ptrace(struct task_struct *child, long request,
973 unsigned long addr, unsigned long data)
974{
975 const struct user_regset_view *view = task_user_regset_view(current);
976 unsigned long addr2 = task_pt_regs(current)->u_regs[UREG_I4];
977 struct pt_regs __user *pregs;
978 struct fps __user *fps;
979 void __user *addr2p;
980 int ret;
981
982 pregs = (struct pt_regs __user *) addr;
983 fps = (struct fps __user *) addr;
984 addr2p = (void __user *) addr2;
985
986 switch (request) {
987 case PTRACE_PEEKUSR:
988 ret = (addr != 0) ? -EIO : 0;
989 break;
990
991 case PTRACE_GETREGS64:
992 ret = copy_regset_to_user(child, view, REGSET_GENERAL,
993 1 * sizeof(u64),
994 15 * sizeof(u64),
995 &pregs->u_regs[0]);
996 if (!ret) {
997 /* XXX doesn't handle 'y' register correctly XXX */
998 ret = copy_regset_to_user(child, view, REGSET_GENERAL,
999 32 * sizeof(u64),
1000 4 * sizeof(u64),
1001 &pregs->tstate);
1002 }
1003 break;
1004
1005 case PTRACE_SETREGS64:
1006 ret = copy_regset_from_user(child, view, REGSET_GENERAL,
1007 1 * sizeof(u64),
1008 15 * sizeof(u64),
1009 &pregs->u_regs[0]);
1010 if (!ret) {
1011 /* XXX doesn't handle 'y' register correctly XXX */
1012 ret = copy_regset_from_user(child, view, REGSET_GENERAL,
1013 32 * sizeof(u64),
1014 4 * sizeof(u64),
1015 &pregs->tstate);
1016 }
1017 break;
1018
1019 case PTRACE_GETFPREGS64:
1020 ret = copy_regset_to_user(child, view, REGSET_FP,
1021 0 * sizeof(u64),
1022 33 * sizeof(u64),
1023 fps);
1024 break;
1025
1026 case PTRACE_SETFPREGS64:
1027 ret = copy_regset_from_user(child, view, REGSET_FP,
1028 0 * sizeof(u64),
1029 33 * sizeof(u64),
1030 fps);
1031 break;
1032
1033 case PTRACE_READTEXT:
1034 case PTRACE_READDATA:
1035 ret = ptrace_readdata(child, addr, addr2p, data);
1036 if (ret == data)
1037 ret = 0;
1038 else if (ret >= 0)
1039 ret = -EIO;
1040 break;
1041
1042 case PTRACE_WRITETEXT:
1043 case PTRACE_WRITEDATA:
1044 ret = ptrace_writedata(child, addr2p, addr, data);
1045 if (ret == data)
1046 ret = 0;
1047 else if (ret >= 0)
1048 ret = -EIO;
1049 break;
1050
1051 default:
1052 if (request == PTRACE_SPARC_DETACH)
1053 request = PTRACE_DETACH;
1054 ret = ptrace_request(child, request, addr, data);
1055 break;
1056 }
1057
1058 return ret;
1059}
1060
1061asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1062{
1063 int ret = 0;
1064
1065 /* do the secure computing check first */
1066 secure_computing(regs->u_regs[UREG_G1]);
1067
1068 if (test_thread_flag(TIF_SYSCALL_TRACE))
1069 ret = tracehook_report_syscall_entry(regs);
1070
1071 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1072 trace_sys_enter(regs, regs->u_regs[UREG_G1]);
1073
1074 if (unlikely(current->audit_context) && !ret)
1075 audit_syscall_entry((test_thread_flag(TIF_32BIT) ?
1076 AUDIT_ARCH_SPARC :
1077 AUDIT_ARCH_SPARC64),
1078 regs->u_regs[UREG_G1],
1079 regs->u_regs[UREG_I0],
1080 regs->u_regs[UREG_I1],
1081 regs->u_regs[UREG_I2],
1082 regs->u_regs[UREG_I3]);
1083
1084 return ret;
1085}
1086
1087asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1088{
1089#ifdef CONFIG_AUDITSYSCALL
1090 if (unlikely(current->audit_context)) {
1091 unsigned long tstate = regs->tstate;
1092 int result = AUDITSC_SUCCESS;
1093
1094 if (unlikely(tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
1095 result = AUDITSC_FAILURE;
1096
1097 audit_syscall_exit(result, regs->u_regs[UREG_I0]);
1098 }
1099#endif
1100 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1101 trace_sys_exit(regs, regs->u_regs[UREG_G1]);
1102
1103 if (test_thread_flag(TIF_SYSCALL_TRACE))
1104 tracehook_report_syscall_exit(regs, 0);
1105}
1// SPDX-License-Identifier: GPL-2.0-only
2/* ptrace.c: Sparc process tracing support.
3 *
4 * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
5 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 *
7 * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
8 * and David Mosberger.
9 *
10 * Added Linux support -miguel (weird, eh?, the original code was meant
11 * to emulate SunOS).
12 */
13
14#include <linux/kernel.h>
15#include <linux/sched.h>
16#include <linux/sched/task_stack.h>
17#include <linux/mm.h>
18#include <linux/errno.h>
19#include <linux/export.h>
20#include <linux/ptrace.h>
21#include <linux/user.h>
22#include <linux/smp.h>
23#include <linux/security.h>
24#include <linux/seccomp.h>
25#include <linux/audit.h>
26#include <linux/signal.h>
27#include <linux/regset.h>
28#include <linux/tracehook.h>
29#include <trace/syscall.h>
30#include <linux/compat.h>
31#include <linux/elf.h>
32#include <linux/context_tracking.h>
33
34#include <asm/asi.h>
35#include <linux/uaccess.h>
36#include <asm/psrcompat.h>
37#include <asm/visasm.h>
38#include <asm/spitfire.h>
39#include <asm/page.h>
40#include <asm/cpudata.h>
41#include <asm/cacheflush.h>
42
43#define CREATE_TRACE_POINTS
44#include <trace/events/syscalls.h>
45
46#include "entry.h"
47
48/* #define ALLOW_INIT_TRACING */
49
50struct pt_regs_offset {
51 const char *name;
52 int offset;
53};
54
55#define REG_OFFSET_NAME(n, r) \
56 {.name = n, .offset = (PT_V9_##r)}
57#define REG_OFFSET_END {.name = NULL, .offset = 0}
58
59static const struct pt_regs_offset regoffset_table[] = {
60 REG_OFFSET_NAME("g0", G0),
61 REG_OFFSET_NAME("g1", G1),
62 REG_OFFSET_NAME("g2", G2),
63 REG_OFFSET_NAME("g3", G3),
64 REG_OFFSET_NAME("g4", G4),
65 REG_OFFSET_NAME("g5", G5),
66 REG_OFFSET_NAME("g6", G6),
67 REG_OFFSET_NAME("g7", G7),
68
69 REG_OFFSET_NAME("i0", I0),
70 REG_OFFSET_NAME("i1", I1),
71 REG_OFFSET_NAME("i2", I2),
72 REG_OFFSET_NAME("i3", I3),
73 REG_OFFSET_NAME("i4", I4),
74 REG_OFFSET_NAME("i5", I5),
75 REG_OFFSET_NAME("i6", I6),
76 REG_OFFSET_NAME("i7", I7),
77
78 REG_OFFSET_NAME("tstate", TSTATE),
79 REG_OFFSET_NAME("pc", TPC),
80 REG_OFFSET_NAME("npc", TNPC),
81 REG_OFFSET_NAME("y", Y),
82 REG_OFFSET_NAME("lr", I7),
83
84 REG_OFFSET_END,
85};
86
87/*
88 * Called by kernel/ptrace.c when detaching..
89 *
90 * Make sure single step bits etc are not set.
91 */
92void ptrace_disable(struct task_struct *child)
93{
94 /* nothing to do */
95}
96
97/* To get the necessary page struct, access_process_vm() first calls
98 * get_user_pages(). This has done a flush_dcache_page() on the
99 * accessed page. Then our caller (copy_{to,from}_user_page()) did
100 * to memcpy to read/write the data from that page.
101 *
102 * Now, the only thing we have to do is:
103 * 1) flush the D-cache if it's possible than an illegal alias
104 * has been created
105 * 2) flush the I-cache if this is pre-cheetah and we did a write
106 */
107void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
108 unsigned long uaddr, void *kaddr,
109 unsigned long len, int write)
110{
111 BUG_ON(len > PAGE_SIZE);
112
113 if (tlb_type == hypervisor)
114 return;
115
116 preempt_disable();
117
118#ifdef DCACHE_ALIASING_POSSIBLE
119 /* If bit 13 of the kernel address we used to access the
120 * user page is the same as the virtual address that page
121 * is mapped to in the user's address space, we can skip the
122 * D-cache flush.
123 */
124 if ((uaddr ^ (unsigned long) kaddr) & (1UL << 13)) {
125 unsigned long start = __pa(kaddr);
126 unsigned long end = start + len;
127 unsigned long dcache_line_size;
128
129 dcache_line_size = local_cpu_data().dcache_line_size;
130
131 if (tlb_type == spitfire) {
132 for (; start < end; start += dcache_line_size)
133 spitfire_put_dcache_tag(start & 0x3fe0, 0x0);
134 } else {
135 start &= ~(dcache_line_size - 1);
136 for (; start < end; start += dcache_line_size)
137 __asm__ __volatile__(
138 "stxa %%g0, [%0] %1\n\t"
139 "membar #Sync"
140 : /* no outputs */
141 : "r" (start),
142 "i" (ASI_DCACHE_INVALIDATE));
143 }
144 }
145#endif
146 if (write && tlb_type == spitfire) {
147 unsigned long start = (unsigned long) kaddr;
148 unsigned long end = start + len;
149 unsigned long icache_line_size;
150
151 icache_line_size = local_cpu_data().icache_line_size;
152
153 for (; start < end; start += icache_line_size)
154 flushi(start);
155 }
156
157 preempt_enable();
158}
159EXPORT_SYMBOL_GPL(flush_ptrace_access);
160
161static int get_from_target(struct task_struct *target, unsigned long uaddr,
162 void *kbuf, int len)
163{
164 if (target == current) {
165 if (copy_from_user(kbuf, (void __user *) uaddr, len))
166 return -EFAULT;
167 } else {
168 int len2 = access_process_vm(target, uaddr, kbuf, len,
169 FOLL_FORCE);
170 if (len2 != len)
171 return -EFAULT;
172 }
173 return 0;
174}
175
176static int set_to_target(struct task_struct *target, unsigned long uaddr,
177 void *kbuf, int len)
178{
179 if (target == current) {
180 if (copy_to_user((void __user *) uaddr, kbuf, len))
181 return -EFAULT;
182 } else {
183 int len2 = access_process_vm(target, uaddr, kbuf, len,
184 FOLL_FORCE | FOLL_WRITE);
185 if (len2 != len)
186 return -EFAULT;
187 }
188 return 0;
189}
190
191static int regwindow64_get(struct task_struct *target,
192 const struct pt_regs *regs,
193 struct reg_window *wbuf)
194{
195 unsigned long rw_addr = regs->u_regs[UREG_I6];
196
197 if (!test_thread_64bit_stack(rw_addr)) {
198 struct reg_window32 win32;
199 int i;
200
201 if (get_from_target(target, rw_addr, &win32, sizeof(win32)))
202 return -EFAULT;
203 for (i = 0; i < 8; i++)
204 wbuf->locals[i] = win32.locals[i];
205 for (i = 0; i < 8; i++)
206 wbuf->ins[i] = win32.ins[i];
207 } else {
208 rw_addr += STACK_BIAS;
209 if (get_from_target(target, rw_addr, wbuf, sizeof(*wbuf)))
210 return -EFAULT;
211 }
212
213 return 0;
214}
215
216static int regwindow64_set(struct task_struct *target,
217 const struct pt_regs *regs,
218 struct reg_window *wbuf)
219{
220 unsigned long rw_addr = regs->u_regs[UREG_I6];
221
222 if (!test_thread_64bit_stack(rw_addr)) {
223 struct reg_window32 win32;
224 int i;
225
226 for (i = 0; i < 8; i++)
227 win32.locals[i] = wbuf->locals[i];
228 for (i = 0; i < 8; i++)
229 win32.ins[i] = wbuf->ins[i];
230
231 if (set_to_target(target, rw_addr, &win32, sizeof(win32)))
232 return -EFAULT;
233 } else {
234 rw_addr += STACK_BIAS;
235 if (set_to_target(target, rw_addr, wbuf, sizeof(*wbuf)))
236 return -EFAULT;
237 }
238
239 return 0;
240}
241
242enum sparc_regset {
243 REGSET_GENERAL,
244 REGSET_FP,
245};
246
247static int genregs64_get(struct task_struct *target,
248 const struct user_regset *regset,
249 struct membuf to)
250{
251 const struct pt_regs *regs = task_pt_regs(target);
252 struct reg_window window;
253
254 if (target == current)
255 flushw_user();
256
257 membuf_write(&to, regs->u_regs, 16 * sizeof(u64));
258 if (!to.left)
259 return 0;
260 if (regwindow64_get(target, regs, &window))
261 return -EFAULT;
262 membuf_write(&to, &window, 16 * sizeof(u64));
263 /* TSTATE, TPC, TNPC */
264 membuf_write(&to, ®s->tstate, 3 * sizeof(u64));
265 return membuf_store(&to, (u64)regs->y);
266}
267
268static int genregs64_set(struct task_struct *target,
269 const struct user_regset *regset,
270 unsigned int pos, unsigned int count,
271 const void *kbuf, const void __user *ubuf)
272{
273 struct pt_regs *regs = task_pt_regs(target);
274 int ret;
275
276 if (target == current)
277 flushw_user();
278
279 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
280 regs->u_regs,
281 0, 16 * sizeof(u64));
282 if (!ret && count && pos < (32 * sizeof(u64))) {
283 struct reg_window window;
284
285 if (regwindow64_get(target, regs, &window))
286 return -EFAULT;
287
288 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
289 &window,
290 16 * sizeof(u64),
291 32 * sizeof(u64));
292
293 if (!ret &&
294 regwindow64_set(target, regs, &window))
295 return -EFAULT;
296 }
297
298 if (!ret && count > 0) {
299 unsigned long tstate;
300
301 /* TSTATE */
302 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
303 &tstate,
304 32 * sizeof(u64),
305 33 * sizeof(u64));
306 if (!ret) {
307 /* Only the condition codes and the "in syscall"
308 * state can be modified in the %tstate register.
309 */
310 tstate &= (TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
311 regs->tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
312 regs->tstate |= tstate;
313 }
314 }
315
316 if (!ret) {
317 /* TPC, TNPC */
318 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
319 ®s->tpc,
320 33 * sizeof(u64),
321 35 * sizeof(u64));
322 }
323
324 if (!ret) {
325 unsigned long y = regs->y;
326
327 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
328 &y,
329 35 * sizeof(u64),
330 36 * sizeof(u64));
331 if (!ret)
332 regs->y = y;
333 }
334
335 if (!ret)
336 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
337 36 * sizeof(u64), -1);
338
339 return ret;
340}
341
342static int fpregs64_get(struct task_struct *target,
343 const struct user_regset *regset,
344 struct membuf to)
345{
346 struct thread_info *t = task_thread_info(target);
347 unsigned long fprs;
348
349 if (target == current)
350 save_and_clear_fpu();
351
352 fprs = t->fpsaved[0];
353
354 if (fprs & FPRS_DL)
355 membuf_write(&to, t->fpregs, 16 * sizeof(u64));
356 else
357 membuf_zero(&to, 16 * sizeof(u64));
358
359 if (fprs & FPRS_DU)
360 membuf_write(&to, t->fpregs + 16, 16 * sizeof(u64));
361 else
362 membuf_zero(&to, 16 * sizeof(u64));
363 if (fprs & FPRS_FEF) {
364 membuf_store(&to, t->xfsr[0]);
365 membuf_store(&to, t->gsr[0]);
366 } else {
367 membuf_zero(&to, 2 * sizeof(u64));
368 }
369 return membuf_store(&to, fprs);
370}
371
372static int fpregs64_set(struct task_struct *target,
373 const struct user_regset *regset,
374 unsigned int pos, unsigned int count,
375 const void *kbuf, const void __user *ubuf)
376{
377 unsigned long *fpregs = task_thread_info(target)->fpregs;
378 unsigned long fprs;
379 int ret;
380
381 if (target == current)
382 save_and_clear_fpu();
383
384 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
385 fpregs,
386 0, 32 * sizeof(u64));
387 if (!ret)
388 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
389 task_thread_info(target)->xfsr,
390 32 * sizeof(u64),
391 33 * sizeof(u64));
392 if (!ret)
393 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
394 task_thread_info(target)->gsr,
395 33 * sizeof(u64),
396 34 * sizeof(u64));
397
398 fprs = task_thread_info(target)->fpsaved[0];
399 if (!ret && count > 0) {
400 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
401 &fprs,
402 34 * sizeof(u64),
403 35 * sizeof(u64));
404 }
405
406 fprs |= (FPRS_FEF | FPRS_DL | FPRS_DU);
407 task_thread_info(target)->fpsaved[0] = fprs;
408
409 if (!ret)
410 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
411 35 * sizeof(u64), -1);
412 return ret;
413}
414
415static const struct user_regset sparc64_regsets[] = {
416 /* Format is:
417 * G0 --> G7
418 * O0 --> O7
419 * L0 --> L7
420 * I0 --> I7
421 * TSTATE, TPC, TNPC, Y
422 */
423 [REGSET_GENERAL] = {
424 .core_note_type = NT_PRSTATUS,
425 .n = 36,
426 .size = sizeof(u64), .align = sizeof(u64),
427 .regset_get = genregs64_get, .set = genregs64_set
428 },
429 /* Format is:
430 * F0 --> F63
431 * FSR
432 * GSR
433 * FPRS
434 */
435 [REGSET_FP] = {
436 .core_note_type = NT_PRFPREG,
437 .n = 35,
438 .size = sizeof(u64), .align = sizeof(u64),
439 .regset_get = fpregs64_get, .set = fpregs64_set
440 },
441};
442
443static int getregs64_get(struct task_struct *target,
444 const struct user_regset *regset,
445 struct membuf to)
446{
447 const struct pt_regs *regs = task_pt_regs(target);
448
449 if (target == current)
450 flushw_user();
451
452 membuf_write(&to, regs->u_regs + 1, 15 * sizeof(u64));
453 membuf_store(&to, (u64)0);
454 membuf_write(&to, ®s->tstate, 3 * sizeof(u64));
455 return membuf_store(&to, (u64)regs->y);
456}
457
458static int setregs64_set(struct task_struct *target,
459 const struct user_regset *regset,
460 unsigned int pos, unsigned int count,
461 const void *kbuf, const void __user *ubuf)
462{
463 struct pt_regs *regs = task_pt_regs(target);
464 unsigned long y = regs->y;
465 unsigned long tstate;
466 int ret;
467
468 if (target == current)
469 flushw_user();
470
471 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
472 regs->u_regs + 1,
473 0 * sizeof(u64),
474 15 * sizeof(u64));
475 if (ret)
476 return ret;
477 ret =user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
478 15 * sizeof(u64), 16 * sizeof(u64));
479 if (ret)
480 return ret;
481 /* TSTATE */
482 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
483 &tstate,
484 16 * sizeof(u64),
485 17 * sizeof(u64));
486 if (ret)
487 return ret;
488 /* Only the condition codes and the "in syscall"
489 * state can be modified in the %tstate register.
490 */
491 tstate &= (TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
492 regs->tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
493 regs->tstate |= tstate;
494
495 /* TPC, TNPC */
496 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
497 ®s->tpc,
498 17 * sizeof(u64),
499 19 * sizeof(u64));
500 if (ret)
501 return ret;
502 /* Y */
503 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
504 &y,
505 19 * sizeof(u64),
506 20 * sizeof(u64));
507 if (!ret)
508 regs->y = y;
509 return ret;
510}
511
512static const struct user_regset ptrace64_regsets[] = {
513 /* Format is:
514 * G1 --> G7
515 * O0 --> O7
516 * 0
517 * TSTATE, TPC, TNPC, Y
518 */
519 [REGSET_GENERAL] = {
520 .n = 20, .size = sizeof(u64),
521 .regset_get = getregs64_get, .set = setregs64_set,
522 },
523};
524
525static const struct user_regset_view ptrace64_view = {
526 .regsets = ptrace64_regsets, .n = ARRAY_SIZE(ptrace64_regsets)
527};
528
529static const struct user_regset_view user_sparc64_view = {
530 .name = "sparc64", .e_machine = EM_SPARCV9,
531 .regsets = sparc64_regsets, .n = ARRAY_SIZE(sparc64_regsets)
532};
533
534#ifdef CONFIG_COMPAT
535static int genregs32_get(struct task_struct *target,
536 const struct user_regset *regset,
537 struct membuf to)
538{
539 const struct pt_regs *regs = task_pt_regs(target);
540 u32 uregs[16];
541 int i;
542
543 if (target == current)
544 flushw_user();
545
546 for (i = 0; i < 16; i++)
547 membuf_store(&to, (u32)regs->u_regs[i]);
548 if (!to.left)
549 return 0;
550 if (get_from_target(target, regs->u_regs[UREG_I6],
551 uregs, sizeof(uregs)))
552 return -EFAULT;
553 membuf_write(&to, uregs, 16 * sizeof(u32));
554 membuf_store(&to, (u32)tstate_to_psr(regs->tstate));
555 membuf_store(&to, (u32)(regs->tpc));
556 membuf_store(&to, (u32)(regs->tnpc));
557 membuf_store(&to, (u32)(regs->y));
558 return membuf_zero(&to, 2 * sizeof(u32));
559}
560
561static int genregs32_set(struct task_struct *target,
562 const struct user_regset *regset,
563 unsigned int pos, unsigned int count,
564 const void *kbuf, const void __user *ubuf)
565{
566 struct pt_regs *regs = task_pt_regs(target);
567 compat_ulong_t __user *reg_window;
568 const compat_ulong_t *k = kbuf;
569 const compat_ulong_t __user *u = ubuf;
570 compat_ulong_t reg;
571
572 if (target == current)
573 flushw_user();
574
575 pos /= sizeof(reg);
576 count /= sizeof(reg);
577
578 if (kbuf) {
579 for (; count > 0 && pos < 16; count--)
580 regs->u_regs[pos++] = *k++;
581
582 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
583 reg_window -= 16;
584 if (target == current) {
585 for (; count > 0 && pos < 32; count--) {
586 if (put_user(*k++, ®_window[pos++]))
587 return -EFAULT;
588 }
589 } else {
590 for (; count > 0 && pos < 32; count--) {
591 if (access_process_vm(target,
592 (unsigned long)
593 ®_window[pos],
594 (void *) k,
595 sizeof(*k),
596 FOLL_FORCE | FOLL_WRITE)
597 != sizeof(*k))
598 return -EFAULT;
599 k++;
600 pos++;
601 }
602 }
603 } else {
604 for (; count > 0 && pos < 16; count--) {
605 if (get_user(reg, u++))
606 return -EFAULT;
607 regs->u_regs[pos++] = reg;
608 }
609
610 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
611 reg_window -= 16;
612 if (target == current) {
613 for (; count > 0 && pos < 32; count--) {
614 if (get_user(reg, u++) ||
615 put_user(reg, ®_window[pos++]))
616 return -EFAULT;
617 }
618 } else {
619 for (; count > 0 && pos < 32; count--) {
620 if (get_user(reg, u++))
621 return -EFAULT;
622 if (access_process_vm(target,
623 (unsigned long)
624 ®_window[pos],
625 ®, sizeof(reg),
626 FOLL_FORCE | FOLL_WRITE)
627 != sizeof(reg))
628 return -EFAULT;
629 pos++;
630 u++;
631 }
632 }
633 }
634 while (count > 0) {
635 unsigned long tstate;
636
637 if (kbuf)
638 reg = *k++;
639 else if (get_user(reg, u++))
640 return -EFAULT;
641
642 switch (pos) {
643 case 32: /* PSR */
644 tstate = regs->tstate;
645 tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
646 tstate |= psr_to_tstate_icc(reg);
647 if (reg & PSR_SYSCALL)
648 tstate |= TSTATE_SYSCALL;
649 regs->tstate = tstate;
650 break;
651 case 33: /* PC */
652 regs->tpc = reg;
653 break;
654 case 34: /* NPC */
655 regs->tnpc = reg;
656 break;
657 case 35: /* Y */
658 regs->y = reg;
659 break;
660 case 36: /* WIM */
661 case 37: /* TBR */
662 break;
663 default:
664 goto finish;
665 }
666
667 pos++;
668 count--;
669 }
670finish:
671 pos *= sizeof(reg);
672 count *= sizeof(reg);
673
674 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
675 38 * sizeof(reg), -1);
676}
677
678static int fpregs32_get(struct task_struct *target,
679 const struct user_regset *regset,
680 struct membuf to)
681{
682 struct thread_info *t = task_thread_info(target);
683 bool enabled;
684
685 if (target == current)
686 save_and_clear_fpu();
687
688 enabled = t->fpsaved[0] & FPRS_FEF;
689
690 membuf_write(&to, t->fpregs, 32 * sizeof(u32));
691 membuf_zero(&to, sizeof(u32));
692 if (enabled)
693 membuf_store(&to, (u32)t->xfsr[0]);
694 else
695 membuf_zero(&to, sizeof(u32));
696 membuf_store(&to, (u32)((enabled << 8) | (8 << 16)));
697 return membuf_zero(&to, 64 * sizeof(u32));
698}
699
700static int fpregs32_set(struct task_struct *target,
701 const struct user_regset *regset,
702 unsigned int pos, unsigned int count,
703 const void *kbuf, const void __user *ubuf)
704{
705 unsigned long *fpregs = task_thread_info(target)->fpregs;
706 unsigned long fprs;
707 int ret;
708
709 if (target == current)
710 save_and_clear_fpu();
711
712 fprs = task_thread_info(target)->fpsaved[0];
713
714 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
715 fpregs,
716 0, 32 * sizeof(u32));
717 if (!ret)
718 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
719 32 * sizeof(u32),
720 33 * sizeof(u32));
721 if (!ret && count > 0) {
722 compat_ulong_t fsr;
723 unsigned long val;
724
725 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
726 &fsr,
727 33 * sizeof(u32),
728 34 * sizeof(u32));
729 if (!ret) {
730 val = task_thread_info(target)->xfsr[0];
731 val &= 0xffffffff00000000UL;
732 val |= fsr;
733 task_thread_info(target)->xfsr[0] = val;
734 }
735 }
736
737 fprs |= (FPRS_FEF | FPRS_DL);
738 task_thread_info(target)->fpsaved[0] = fprs;
739
740 if (!ret)
741 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
742 34 * sizeof(u32), -1);
743 return ret;
744}
745
746static const struct user_regset sparc32_regsets[] = {
747 /* Format is:
748 * G0 --> G7
749 * O0 --> O7
750 * L0 --> L7
751 * I0 --> I7
752 * PSR, PC, nPC, Y, WIM, TBR
753 */
754 [REGSET_GENERAL] = {
755 .core_note_type = NT_PRSTATUS,
756 .n = 38,
757 .size = sizeof(u32), .align = sizeof(u32),
758 .regset_get = genregs32_get, .set = genregs32_set
759 },
760 /* Format is:
761 * F0 --> F31
762 * empty 32-bit word
763 * FSR (32--bit word)
764 * FPU QUEUE COUNT (8-bit char)
765 * FPU QUEUE ENTRYSIZE (8-bit char)
766 * FPU ENABLED (8-bit char)
767 * empty 8-bit char
768 * FPU QUEUE (64 32-bit ints)
769 */
770 [REGSET_FP] = {
771 .core_note_type = NT_PRFPREG,
772 .n = 99,
773 .size = sizeof(u32), .align = sizeof(u32),
774 .regset_get = fpregs32_get, .set = fpregs32_set
775 },
776};
777
778static int getregs_get(struct task_struct *target,
779 const struct user_regset *regset,
780 struct membuf to)
781{
782 const struct pt_regs *regs = task_pt_regs(target);
783 int i;
784
785 if (target == current)
786 flushw_user();
787
788 membuf_store(&to, (u32)tstate_to_psr(regs->tstate));
789 membuf_store(&to, (u32)(regs->tpc));
790 membuf_store(&to, (u32)(regs->tnpc));
791 membuf_store(&to, (u32)(regs->y));
792 for (i = 1; i < 16; i++)
793 membuf_store(&to, (u32)regs->u_regs[i]);
794 return to.left;
795}
796
797static int setregs_set(struct task_struct *target,
798 const struct user_regset *regset,
799 unsigned int pos, unsigned int count,
800 const void *kbuf, const void __user *ubuf)
801{
802 struct pt_regs *regs = task_pt_regs(target);
803 unsigned long tstate;
804 u32 uregs[19];
805 int i, ret;
806
807 if (target == current)
808 flushw_user();
809
810 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
811 uregs,
812 0, 19 * sizeof(u32));
813 if (ret)
814 return ret;
815
816 tstate = regs->tstate;
817 tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
818 tstate |= psr_to_tstate_icc(uregs[0]);
819 if (uregs[0] & PSR_SYSCALL)
820 tstate |= TSTATE_SYSCALL;
821 regs->tstate = tstate;
822 regs->tpc = uregs[1];
823 regs->tnpc = uregs[2];
824 regs->y = uregs[3];
825
826 for (i = 1; i < 15; i++)
827 regs->u_regs[i] = uregs[3 + i];
828 return 0;
829}
830
831static int getfpregs_get(struct task_struct *target,
832 const struct user_regset *regset,
833 struct membuf to)
834{
835 struct thread_info *t = task_thread_info(target);
836
837 if (target == current)
838 save_and_clear_fpu();
839
840 membuf_write(&to, t->fpregs, 32 * sizeof(u32));
841 if (t->fpsaved[0] & FPRS_FEF)
842 membuf_store(&to, (u32)t->xfsr[0]);
843 else
844 membuf_zero(&to, sizeof(u32));
845 return membuf_zero(&to, 35 * sizeof(u32));
846}
847
848static int setfpregs_set(struct task_struct *target,
849 const struct user_regset *regset,
850 unsigned int pos, unsigned int count,
851 const void *kbuf, const void __user *ubuf)
852{
853 unsigned long *fpregs = task_thread_info(target)->fpregs;
854 unsigned long fprs;
855 int ret;
856
857 if (target == current)
858 save_and_clear_fpu();
859
860 fprs = task_thread_info(target)->fpsaved[0];
861
862 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
863 fpregs,
864 0, 32 * sizeof(u32));
865 if (!ret) {
866 compat_ulong_t fsr;
867 unsigned long val;
868
869 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
870 &fsr,
871 32 * sizeof(u32),
872 33 * sizeof(u32));
873 if (!ret) {
874 val = task_thread_info(target)->xfsr[0];
875 val &= 0xffffffff00000000UL;
876 val |= fsr;
877 task_thread_info(target)->xfsr[0] = val;
878 }
879 }
880
881 fprs |= (FPRS_FEF | FPRS_DL);
882 task_thread_info(target)->fpsaved[0] = fprs;
883 return ret;
884}
885
886static const struct user_regset ptrace32_regsets[] = {
887 [REGSET_GENERAL] = {
888 .n = 19, .size = sizeof(u32),
889 .regset_get = getregs_get, .set = setregs_set,
890 },
891 [REGSET_FP] = {
892 .n = 68, .size = sizeof(u32),
893 .regset_get = getfpregs_get, .set = setfpregs_set,
894 },
895};
896
897static const struct user_regset_view ptrace32_view = {
898 .regsets = ptrace32_regsets, .n = ARRAY_SIZE(ptrace32_regsets)
899};
900
901static const struct user_regset_view user_sparc32_view = {
902 .name = "sparc", .e_machine = EM_SPARC,
903 .regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
904};
905#endif /* CONFIG_COMPAT */
906
907const struct user_regset_view *task_user_regset_view(struct task_struct *task)
908{
909#ifdef CONFIG_COMPAT
910 if (test_tsk_thread_flag(task, TIF_32BIT))
911 return &user_sparc32_view;
912#endif
913 return &user_sparc64_view;
914}
915
916#ifdef CONFIG_COMPAT
917struct compat_fps {
918 unsigned int regs[32];
919 unsigned int fsr;
920 unsigned int flags;
921 unsigned int extra;
922 unsigned int fpqd;
923 struct compat_fq {
924 unsigned int insnaddr;
925 unsigned int insn;
926 } fpq[16];
927};
928
929long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
930 compat_ulong_t caddr, compat_ulong_t cdata)
931{
932 compat_ulong_t caddr2 = task_pt_regs(current)->u_regs[UREG_I4];
933 struct pt_regs32 __user *pregs;
934 struct compat_fps __user *fps;
935 unsigned long addr2 = caddr2;
936 unsigned long addr = caddr;
937 unsigned long data = cdata;
938 int ret;
939
940 pregs = (struct pt_regs32 __user *) addr;
941 fps = (struct compat_fps __user *) addr;
942
943 switch (request) {
944 case PTRACE_PEEKUSR:
945 ret = (addr != 0) ? -EIO : 0;
946 break;
947
948 case PTRACE_GETREGS:
949 ret = copy_regset_to_user(child, &ptrace32_view,
950 REGSET_GENERAL, 0,
951 19 * sizeof(u32),
952 pregs);
953 break;
954
955 case PTRACE_SETREGS:
956 ret = copy_regset_from_user(child, &ptrace32_view,
957 REGSET_GENERAL, 0,
958 19 * sizeof(u32),
959 pregs);
960 break;
961
962 case PTRACE_GETFPREGS:
963 ret = copy_regset_to_user(child, &ptrace32_view,
964 REGSET_FP, 0,
965 68 * sizeof(u32),
966 fps);
967 break;
968
969 case PTRACE_SETFPREGS:
970 ret = copy_regset_from_user(child, &ptrace32_view,
971 REGSET_FP, 0,
972 33 * sizeof(u32),
973 fps);
974 break;
975
976 case PTRACE_READTEXT:
977 case PTRACE_READDATA:
978 ret = ptrace_readdata(child, addr,
979 (char __user *)addr2, data);
980 if (ret == data)
981 ret = 0;
982 else if (ret >= 0)
983 ret = -EIO;
984 break;
985
986 case PTRACE_WRITETEXT:
987 case PTRACE_WRITEDATA:
988 ret = ptrace_writedata(child, (char __user *) addr2,
989 addr, data);
990 if (ret == data)
991 ret = 0;
992 else if (ret >= 0)
993 ret = -EIO;
994 break;
995
996 default:
997 if (request == PTRACE_SPARC_DETACH)
998 request = PTRACE_DETACH;
999 ret = compat_ptrace_request(child, request, addr, data);
1000 break;
1001 }
1002
1003 return ret;
1004}
1005#endif /* CONFIG_COMPAT */
1006
1007struct fps {
1008 unsigned int regs[64];
1009 unsigned long fsr;
1010};
1011
1012long arch_ptrace(struct task_struct *child, long request,
1013 unsigned long addr, unsigned long data)
1014{
1015 const struct user_regset_view *view = task_user_regset_view(current);
1016 unsigned long addr2 = task_pt_regs(current)->u_regs[UREG_I4];
1017 struct pt_regs __user *pregs;
1018 struct fps __user *fps;
1019 void __user *addr2p;
1020 int ret;
1021
1022 pregs = (struct pt_regs __user *) addr;
1023 fps = (struct fps __user *) addr;
1024 addr2p = (void __user *) addr2;
1025
1026 switch (request) {
1027 case PTRACE_PEEKUSR:
1028 ret = (addr != 0) ? -EIO : 0;
1029 break;
1030
1031 case PTRACE_GETREGS64:
1032 ret = copy_regset_to_user(child, &ptrace64_view,
1033 REGSET_GENERAL, 0,
1034 19 * sizeof(u64),
1035 pregs);
1036 break;
1037
1038 case PTRACE_SETREGS64:
1039 ret = copy_regset_from_user(child, &ptrace64_view,
1040 REGSET_GENERAL, 0,
1041 19 * sizeof(u64),
1042 pregs);
1043 break;
1044
1045 case PTRACE_GETFPREGS64:
1046 ret = copy_regset_to_user(child, view, REGSET_FP,
1047 0 * sizeof(u64),
1048 33 * sizeof(u64),
1049 fps);
1050 break;
1051
1052 case PTRACE_SETFPREGS64:
1053 ret = copy_regset_from_user(child, view, REGSET_FP,
1054 0 * sizeof(u64),
1055 33 * sizeof(u64),
1056 fps);
1057 break;
1058
1059 case PTRACE_READTEXT:
1060 case PTRACE_READDATA:
1061 ret = ptrace_readdata(child, addr, addr2p, data);
1062 if (ret == data)
1063 ret = 0;
1064 else if (ret >= 0)
1065 ret = -EIO;
1066 break;
1067
1068 case PTRACE_WRITETEXT:
1069 case PTRACE_WRITEDATA:
1070 ret = ptrace_writedata(child, addr2p, addr, data);
1071 if (ret == data)
1072 ret = 0;
1073 else if (ret >= 0)
1074 ret = -EIO;
1075 break;
1076
1077 default:
1078 if (request == PTRACE_SPARC_DETACH)
1079 request = PTRACE_DETACH;
1080 ret = ptrace_request(child, request, addr, data);
1081 break;
1082 }
1083
1084 return ret;
1085}
1086
1087asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1088{
1089 int ret = 0;
1090
1091 /* do the secure computing check first */
1092 secure_computing_strict(regs->u_regs[UREG_G1]);
1093
1094 if (test_thread_flag(TIF_NOHZ))
1095 user_exit();
1096
1097 if (test_thread_flag(TIF_SYSCALL_TRACE))
1098 ret = tracehook_report_syscall_entry(regs);
1099
1100 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1101 trace_sys_enter(regs, regs->u_regs[UREG_G1]);
1102
1103 audit_syscall_entry(regs->u_regs[UREG_G1], regs->u_regs[UREG_I0],
1104 regs->u_regs[UREG_I1], regs->u_regs[UREG_I2],
1105 regs->u_regs[UREG_I3]);
1106
1107 return ret;
1108}
1109
1110asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1111{
1112 if (test_thread_flag(TIF_NOHZ))
1113 user_exit();
1114
1115 audit_syscall_exit(regs);
1116
1117 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1118 trace_sys_exit(regs, regs->u_regs[UREG_I0]);
1119
1120 if (test_thread_flag(TIF_SYSCALL_TRACE))
1121 tracehook_report_syscall_exit(regs, 0);
1122
1123 if (test_thread_flag(TIF_NOHZ))
1124 user_enter();
1125}
1126
1127/**
1128 * regs_query_register_offset() - query register offset from its name
1129 * @name: the name of a register
1130 *
1131 * regs_query_register_offset() returns the offset of a register in struct
1132 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
1133 */
1134int regs_query_register_offset(const char *name)
1135{
1136 const struct pt_regs_offset *roff;
1137
1138 for (roff = regoffset_table; roff->name != NULL; roff++)
1139 if (!strcmp(roff->name, name))
1140 return roff->offset;
1141 return -EINVAL;
1142}
1143
1144/**
1145 * regs_within_kernel_stack() - check the address in the stack
1146 * @regs: pt_regs which contains kernel stack pointer.
1147 * @addr: address which is checked.
1148 *
1149 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
1150 * If @addr is within the kernel stack, it returns true. If not, returns false.
1151 */
1152static inline int regs_within_kernel_stack(struct pt_regs *regs,
1153 unsigned long addr)
1154{
1155 unsigned long ksp = kernel_stack_pointer(regs) + STACK_BIAS;
1156 return ((addr & ~(THREAD_SIZE - 1)) ==
1157 (ksp & ~(THREAD_SIZE - 1)));
1158}
1159
1160/**
1161 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1162 * @regs: pt_regs which contains kernel stack pointer.
1163 * @n: stack entry number.
1164 *
1165 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1166 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
1167 * this returns 0.
1168 */
1169unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1170{
1171 unsigned long ksp = kernel_stack_pointer(regs) + STACK_BIAS;
1172 unsigned long *addr = (unsigned long *)ksp;
1173 addr += n;
1174 if (regs_within_kernel_stack(regs, (unsigned long)addr))
1175 return *addr;
1176 else
1177 return 0;
1178}