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