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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Ptrace user space interface.
4 *
5 * Copyright IBM Corp. 1999, 2010
6 * Author(s): Denis Joseph Barrow
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
8 */
9
10#include <linux/kernel.h>
11#include <linux/sched.h>
12#include <linux/sched/task_stack.h>
13#include <linux/mm.h>
14#include <linux/smp.h>
15#include <linux/errno.h>
16#include <linux/ptrace.h>
17#include <linux/user.h>
18#include <linux/security.h>
19#include <linux/audit.h>
20#include <linux/signal.h>
21#include <linux/elf.h>
22#include <linux/regset.h>
23#include <linux/tracehook.h>
24#include <linux/seccomp.h>
25#include <linux/compat.h>
26#include <trace/syscall.h>
27#include <asm/page.h>
28#include <asm/pgtable.h>
29#include <asm/pgalloc.h>
30#include <linux/uaccess.h>
31#include <asm/unistd.h>
32#include <asm/switch_to.h>
33#include <asm/runtime_instr.h>
34#include <asm/facility.h>
35
36#include "entry.h"
37
38#ifdef CONFIG_COMPAT
39#include "compat_ptrace.h"
40#endif
41
42#define CREATE_TRACE_POINTS
43#include <trace/events/syscalls.h>
44
45void update_cr_regs(struct task_struct *task)
46{
47 struct pt_regs *regs = task_pt_regs(task);
48 struct thread_struct *thread = &task->thread;
49 struct per_regs old, new;
50 union ctlreg0 cr0_old, cr0_new;
51 union ctlreg2 cr2_old, cr2_new;
52 int cr0_changed, cr2_changed;
53
54 __ctl_store(cr0_old.val, 0, 0);
55 __ctl_store(cr2_old.val, 2, 2);
56 cr0_new = cr0_old;
57 cr2_new = cr2_old;
58 /* Take care of the enable/disable of transactional execution. */
59 if (MACHINE_HAS_TE) {
60 /* Set or clear transaction execution TXC bit 8. */
61 cr0_new.tcx = 1;
62 if (task->thread.per_flags & PER_FLAG_NO_TE)
63 cr0_new.tcx = 0;
64 /* Set or clear transaction execution TDC bits 62 and 63. */
65 cr2_new.tdc = 0;
66 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
67 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
68 cr2_new.tdc = 1;
69 else
70 cr2_new.tdc = 2;
71 }
72 }
73 /* Take care of enable/disable of guarded storage. */
74 if (MACHINE_HAS_GS) {
75 cr2_new.gse = 0;
76 if (task->thread.gs_cb)
77 cr2_new.gse = 1;
78 }
79 /* Load control register 0/2 iff changed */
80 cr0_changed = cr0_new.val != cr0_old.val;
81 cr2_changed = cr2_new.val != cr2_old.val;
82 if (cr0_changed)
83 __ctl_load(cr0_new.val, 0, 0);
84 if (cr2_changed)
85 __ctl_load(cr2_new.val, 2, 2);
86 /* Copy user specified PER registers */
87 new.control = thread->per_user.control;
88 new.start = thread->per_user.start;
89 new.end = thread->per_user.end;
90
91 /* merge TIF_SINGLE_STEP into user specified PER registers. */
92 if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
93 test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
94 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
95 new.control |= PER_EVENT_BRANCH;
96 else
97 new.control |= PER_EVENT_IFETCH;
98 new.control |= PER_CONTROL_SUSPENSION;
99 new.control |= PER_EVENT_TRANSACTION_END;
100 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
101 new.control |= PER_EVENT_IFETCH;
102 new.start = 0;
103 new.end = -1UL;
104 }
105
106 /* Take care of the PER enablement bit in the PSW. */
107 if (!(new.control & PER_EVENT_MASK)) {
108 regs->psw.mask &= ~PSW_MASK_PER;
109 return;
110 }
111 regs->psw.mask |= PSW_MASK_PER;
112 __ctl_store(old, 9, 11);
113 if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
114 __ctl_load(new, 9, 11);
115}
116
117void user_enable_single_step(struct task_struct *task)
118{
119 clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
120 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
121}
122
123void user_disable_single_step(struct task_struct *task)
124{
125 clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
126 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
127}
128
129void user_enable_block_step(struct task_struct *task)
130{
131 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
132 set_tsk_thread_flag(task, TIF_BLOCK_STEP);
133}
134
135/*
136 * Called by kernel/ptrace.c when detaching..
137 *
138 * Clear all debugging related fields.
139 */
140void ptrace_disable(struct task_struct *task)
141{
142 memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
143 memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
144 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
145 clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
146 task->thread.per_flags = 0;
147}
148
149#define __ADDR_MASK 7
150
151static inline unsigned long __peek_user_per(struct task_struct *child,
152 addr_t addr)
153{
154 struct per_struct_kernel *dummy = NULL;
155
156 if (addr == (addr_t) &dummy->cr9)
157 /* Control bits of the active per set. */
158 return test_thread_flag(TIF_SINGLE_STEP) ?
159 PER_EVENT_IFETCH : child->thread.per_user.control;
160 else if (addr == (addr_t) &dummy->cr10)
161 /* Start address of the active per set. */
162 return test_thread_flag(TIF_SINGLE_STEP) ?
163 0 : child->thread.per_user.start;
164 else if (addr == (addr_t) &dummy->cr11)
165 /* End address of the active per set. */
166 return test_thread_flag(TIF_SINGLE_STEP) ?
167 -1UL : child->thread.per_user.end;
168 else if (addr == (addr_t) &dummy->bits)
169 /* Single-step bit. */
170 return test_thread_flag(TIF_SINGLE_STEP) ?
171 (1UL << (BITS_PER_LONG - 1)) : 0;
172 else if (addr == (addr_t) &dummy->starting_addr)
173 /* Start address of the user specified per set. */
174 return child->thread.per_user.start;
175 else if (addr == (addr_t) &dummy->ending_addr)
176 /* End address of the user specified per set. */
177 return child->thread.per_user.end;
178 else if (addr == (addr_t) &dummy->perc_atmid)
179 /* PER code, ATMID and AI of the last PER trap */
180 return (unsigned long)
181 child->thread.per_event.cause << (BITS_PER_LONG - 16);
182 else if (addr == (addr_t) &dummy->address)
183 /* Address of the last PER trap */
184 return child->thread.per_event.address;
185 else if (addr == (addr_t) &dummy->access_id)
186 /* Access id of the last PER trap */
187 return (unsigned long)
188 child->thread.per_event.paid << (BITS_PER_LONG - 8);
189 return 0;
190}
191
192/*
193 * Read the word at offset addr from the user area of a process. The
194 * trouble here is that the information is littered over different
195 * locations. The process registers are found on the kernel stack,
196 * the floating point stuff and the trace settings are stored in
197 * the task structure. In addition the different structures in
198 * struct user contain pad bytes that should be read as zeroes.
199 * Lovely...
200 */
201static unsigned long __peek_user(struct task_struct *child, addr_t addr)
202{
203 struct user *dummy = NULL;
204 addr_t offset, tmp;
205
206 if (addr < (addr_t) &dummy->regs.acrs) {
207 /*
208 * psw and gprs are stored on the stack
209 */
210 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
211 if (addr == (addr_t) &dummy->regs.psw.mask) {
212 /* Return a clean psw mask. */
213 tmp &= PSW_MASK_USER | PSW_MASK_RI;
214 tmp |= PSW_USER_BITS;
215 }
216
217 } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
218 /*
219 * access registers are stored in the thread structure
220 */
221 offset = addr - (addr_t) &dummy->regs.acrs;
222 /*
223 * Very special case: old & broken 64 bit gdb reading
224 * from acrs[15]. Result is a 64 bit value. Read the
225 * 32 bit acrs[15] value and shift it by 32. Sick...
226 */
227 if (addr == (addr_t) &dummy->regs.acrs[15])
228 tmp = ((unsigned long) child->thread.acrs[15]) << 32;
229 else
230 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
231
232 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
233 /*
234 * orig_gpr2 is stored on the kernel stack
235 */
236 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
237
238 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
239 /*
240 * prevent reads of padding hole between
241 * orig_gpr2 and fp_regs on s390.
242 */
243 tmp = 0;
244
245 } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
246 /*
247 * floating point control reg. is in the thread structure
248 */
249 tmp = child->thread.fpu.fpc;
250 tmp <<= BITS_PER_LONG - 32;
251
252 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
253 /*
254 * floating point regs. are either in child->thread.fpu
255 * or the child->thread.fpu.vxrs array
256 */
257 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
258 if (MACHINE_HAS_VX)
259 tmp = *(addr_t *)
260 ((addr_t) child->thread.fpu.vxrs + 2*offset);
261 else
262 tmp = *(addr_t *)
263 ((addr_t) child->thread.fpu.fprs + offset);
264
265 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
266 /*
267 * Handle access to the per_info structure.
268 */
269 addr -= (addr_t) &dummy->regs.per_info;
270 tmp = __peek_user_per(child, addr);
271
272 } else
273 tmp = 0;
274
275 return tmp;
276}
277
278static int
279peek_user(struct task_struct *child, addr_t addr, addr_t data)
280{
281 addr_t tmp, mask;
282
283 /*
284 * Stupid gdb peeks/pokes the access registers in 64 bit with
285 * an alignment of 4. Programmers from hell...
286 */
287 mask = __ADDR_MASK;
288 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
289 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
290 mask = 3;
291 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
292 return -EIO;
293
294 tmp = __peek_user(child, addr);
295 return put_user(tmp, (addr_t __user *) data);
296}
297
298static inline void __poke_user_per(struct task_struct *child,
299 addr_t addr, addr_t data)
300{
301 struct per_struct_kernel *dummy = NULL;
302
303 /*
304 * There are only three fields in the per_info struct that the
305 * debugger user can write to.
306 * 1) cr9: the debugger wants to set a new PER event mask
307 * 2) starting_addr: the debugger wants to set a new starting
308 * address to use with the PER event mask.
309 * 3) ending_addr: the debugger wants to set a new ending
310 * address to use with the PER event mask.
311 * The user specified PER event mask and the start and end
312 * addresses are used only if single stepping is not in effect.
313 * Writes to any other field in per_info are ignored.
314 */
315 if (addr == (addr_t) &dummy->cr9)
316 /* PER event mask of the user specified per set. */
317 child->thread.per_user.control =
318 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
319 else if (addr == (addr_t) &dummy->starting_addr)
320 /* Starting address of the user specified per set. */
321 child->thread.per_user.start = data;
322 else if (addr == (addr_t) &dummy->ending_addr)
323 /* Ending address of the user specified per set. */
324 child->thread.per_user.end = data;
325}
326
327/*
328 * Write a word to the user area of a process at location addr. This
329 * operation does have an additional problem compared to peek_user.
330 * Stores to the program status word and on the floating point
331 * control register needs to get checked for validity.
332 */
333static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
334{
335 struct user *dummy = NULL;
336 addr_t offset;
337
338 if (addr < (addr_t) &dummy->regs.acrs) {
339 /*
340 * psw and gprs are stored on the stack
341 */
342 if (addr == (addr_t) &dummy->regs.psw.mask) {
343 unsigned long mask = PSW_MASK_USER;
344
345 mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
346 if ((data ^ PSW_USER_BITS) & ~mask)
347 /* Invalid psw mask. */
348 return -EINVAL;
349 if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
350 /* Invalid address-space-control bits */
351 return -EINVAL;
352 if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
353 /* Invalid addressing mode bits */
354 return -EINVAL;
355 }
356 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
357
358 } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
359 /*
360 * access registers are stored in the thread structure
361 */
362 offset = addr - (addr_t) &dummy->regs.acrs;
363 /*
364 * Very special case: old & broken 64 bit gdb writing
365 * to acrs[15] with a 64 bit value. Ignore the lower
366 * half of the value and write the upper 32 bit to
367 * acrs[15]. Sick...
368 */
369 if (addr == (addr_t) &dummy->regs.acrs[15])
370 child->thread.acrs[15] = (unsigned int) (data >> 32);
371 else
372 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
373
374 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
375 /*
376 * orig_gpr2 is stored on the kernel stack
377 */
378 task_pt_regs(child)->orig_gpr2 = data;
379
380 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
381 /*
382 * prevent writes of padding hole between
383 * orig_gpr2 and fp_regs on s390.
384 */
385 return 0;
386
387 } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
388 /*
389 * floating point control reg. is in the thread structure
390 */
391 if ((unsigned int) data != 0 ||
392 test_fp_ctl(data >> (BITS_PER_LONG - 32)))
393 return -EINVAL;
394 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
395
396 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
397 /*
398 * floating point regs. are either in child->thread.fpu
399 * or the child->thread.fpu.vxrs array
400 */
401 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
402 if (MACHINE_HAS_VX)
403 *(addr_t *)((addr_t)
404 child->thread.fpu.vxrs + 2*offset) = data;
405 else
406 *(addr_t *)((addr_t)
407 child->thread.fpu.fprs + offset) = data;
408
409 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
410 /*
411 * Handle access to the per_info structure.
412 */
413 addr -= (addr_t) &dummy->regs.per_info;
414 __poke_user_per(child, addr, data);
415
416 }
417
418 return 0;
419}
420
421static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
422{
423 addr_t mask;
424
425 /*
426 * Stupid gdb peeks/pokes the access registers in 64 bit with
427 * an alignment of 4. Programmers from hell indeed...
428 */
429 mask = __ADDR_MASK;
430 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
431 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
432 mask = 3;
433 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
434 return -EIO;
435
436 return __poke_user(child, addr, data);
437}
438
439long arch_ptrace(struct task_struct *child, long request,
440 unsigned long addr, unsigned long data)
441{
442 ptrace_area parea;
443 int copied, ret;
444
445 switch (request) {
446 case PTRACE_PEEKUSR:
447 /* read the word at location addr in the USER area. */
448 return peek_user(child, addr, data);
449
450 case PTRACE_POKEUSR:
451 /* write the word at location addr in the USER area */
452 return poke_user(child, addr, data);
453
454 case PTRACE_PEEKUSR_AREA:
455 case PTRACE_POKEUSR_AREA:
456 if (copy_from_user(&parea, (void __force __user *) addr,
457 sizeof(parea)))
458 return -EFAULT;
459 addr = parea.kernel_addr;
460 data = parea.process_addr;
461 copied = 0;
462 while (copied < parea.len) {
463 if (request == PTRACE_PEEKUSR_AREA)
464 ret = peek_user(child, addr, data);
465 else {
466 addr_t utmp;
467 if (get_user(utmp,
468 (addr_t __force __user *) data))
469 return -EFAULT;
470 ret = poke_user(child, addr, utmp);
471 }
472 if (ret)
473 return ret;
474 addr += sizeof(unsigned long);
475 data += sizeof(unsigned long);
476 copied += sizeof(unsigned long);
477 }
478 return 0;
479 case PTRACE_GET_LAST_BREAK:
480 put_user(child->thread.last_break,
481 (unsigned long __user *) data);
482 return 0;
483 case PTRACE_ENABLE_TE:
484 if (!MACHINE_HAS_TE)
485 return -EIO;
486 child->thread.per_flags &= ~PER_FLAG_NO_TE;
487 return 0;
488 case PTRACE_DISABLE_TE:
489 if (!MACHINE_HAS_TE)
490 return -EIO;
491 child->thread.per_flags |= PER_FLAG_NO_TE;
492 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
493 return 0;
494 case PTRACE_TE_ABORT_RAND:
495 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
496 return -EIO;
497 switch (data) {
498 case 0UL:
499 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
500 break;
501 case 1UL:
502 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
503 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
504 break;
505 case 2UL:
506 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
507 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
508 break;
509 default:
510 return -EINVAL;
511 }
512 return 0;
513 default:
514 return ptrace_request(child, request, addr, data);
515 }
516}
517
518#ifdef CONFIG_COMPAT
519/*
520 * Now the fun part starts... a 31 bit program running in the
521 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
522 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
523 * to handle, the difference to the 64 bit versions of the requests
524 * is that the access is done in multiples of 4 byte instead of
525 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
526 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
527 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
528 * is a 31 bit program too, the content of struct user can be
529 * emulated. A 31 bit program peeking into the struct user of
530 * a 64 bit program is a no-no.
531 */
532
533/*
534 * Same as peek_user_per but for a 31 bit program.
535 */
536static inline __u32 __peek_user_per_compat(struct task_struct *child,
537 addr_t addr)
538{
539 struct compat_per_struct_kernel *dummy32 = NULL;
540
541 if (addr == (addr_t) &dummy32->cr9)
542 /* Control bits of the active per set. */
543 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
544 PER_EVENT_IFETCH : child->thread.per_user.control;
545 else if (addr == (addr_t) &dummy32->cr10)
546 /* Start address of the active per set. */
547 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
548 0 : child->thread.per_user.start;
549 else if (addr == (addr_t) &dummy32->cr11)
550 /* End address of the active per set. */
551 return test_thread_flag(TIF_SINGLE_STEP) ?
552 PSW32_ADDR_INSN : child->thread.per_user.end;
553 else if (addr == (addr_t) &dummy32->bits)
554 /* Single-step bit. */
555 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
556 0x80000000 : 0;
557 else if (addr == (addr_t) &dummy32->starting_addr)
558 /* Start address of the user specified per set. */
559 return (__u32) child->thread.per_user.start;
560 else if (addr == (addr_t) &dummy32->ending_addr)
561 /* End address of the user specified per set. */
562 return (__u32) child->thread.per_user.end;
563 else if (addr == (addr_t) &dummy32->perc_atmid)
564 /* PER code, ATMID and AI of the last PER trap */
565 return (__u32) child->thread.per_event.cause << 16;
566 else if (addr == (addr_t) &dummy32->address)
567 /* Address of the last PER trap */
568 return (__u32) child->thread.per_event.address;
569 else if (addr == (addr_t) &dummy32->access_id)
570 /* Access id of the last PER trap */
571 return (__u32) child->thread.per_event.paid << 24;
572 return 0;
573}
574
575/*
576 * Same as peek_user but for a 31 bit program.
577 */
578static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
579{
580 struct compat_user *dummy32 = NULL;
581 addr_t offset;
582 __u32 tmp;
583
584 if (addr < (addr_t) &dummy32->regs.acrs) {
585 struct pt_regs *regs = task_pt_regs(child);
586 /*
587 * psw and gprs are stored on the stack
588 */
589 if (addr == (addr_t) &dummy32->regs.psw.mask) {
590 /* Fake a 31 bit psw mask. */
591 tmp = (__u32)(regs->psw.mask >> 32);
592 tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
593 tmp |= PSW32_USER_BITS;
594 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
595 /* Fake a 31 bit psw address. */
596 tmp = (__u32) regs->psw.addr |
597 (__u32)(regs->psw.mask & PSW_MASK_BA);
598 } else {
599 /* gpr 0-15 */
600 tmp = *(__u32 *)((addr_t) ®s->psw + addr*2 + 4);
601 }
602 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
603 /*
604 * access registers are stored in the thread structure
605 */
606 offset = addr - (addr_t) &dummy32->regs.acrs;
607 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
608
609 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
610 /*
611 * orig_gpr2 is stored on the kernel stack
612 */
613 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
614
615 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
616 /*
617 * prevent reads of padding hole between
618 * orig_gpr2 and fp_regs on s390.
619 */
620 tmp = 0;
621
622 } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
623 /*
624 * floating point control reg. is in the thread structure
625 */
626 tmp = child->thread.fpu.fpc;
627
628 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
629 /*
630 * floating point regs. are either in child->thread.fpu
631 * or the child->thread.fpu.vxrs array
632 */
633 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
634 if (MACHINE_HAS_VX)
635 tmp = *(__u32 *)
636 ((addr_t) child->thread.fpu.vxrs + 2*offset);
637 else
638 tmp = *(__u32 *)
639 ((addr_t) child->thread.fpu.fprs + offset);
640
641 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
642 /*
643 * Handle access to the per_info structure.
644 */
645 addr -= (addr_t) &dummy32->regs.per_info;
646 tmp = __peek_user_per_compat(child, addr);
647
648 } else
649 tmp = 0;
650
651 return tmp;
652}
653
654static int peek_user_compat(struct task_struct *child,
655 addr_t addr, addr_t data)
656{
657 __u32 tmp;
658
659 if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
660 return -EIO;
661
662 tmp = __peek_user_compat(child, addr);
663 return put_user(tmp, (__u32 __user *) data);
664}
665
666/*
667 * Same as poke_user_per but for a 31 bit program.
668 */
669static inline void __poke_user_per_compat(struct task_struct *child,
670 addr_t addr, __u32 data)
671{
672 struct compat_per_struct_kernel *dummy32 = NULL;
673
674 if (addr == (addr_t) &dummy32->cr9)
675 /* PER event mask of the user specified per set. */
676 child->thread.per_user.control =
677 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
678 else if (addr == (addr_t) &dummy32->starting_addr)
679 /* Starting address of the user specified per set. */
680 child->thread.per_user.start = data;
681 else if (addr == (addr_t) &dummy32->ending_addr)
682 /* Ending address of the user specified per set. */
683 child->thread.per_user.end = data;
684}
685
686/*
687 * Same as poke_user but for a 31 bit program.
688 */
689static int __poke_user_compat(struct task_struct *child,
690 addr_t addr, addr_t data)
691{
692 struct compat_user *dummy32 = NULL;
693 __u32 tmp = (__u32) data;
694 addr_t offset;
695
696 if (addr < (addr_t) &dummy32->regs.acrs) {
697 struct pt_regs *regs = task_pt_regs(child);
698 /*
699 * psw, gprs, acrs and orig_gpr2 are stored on the stack
700 */
701 if (addr == (addr_t) &dummy32->regs.psw.mask) {
702 __u32 mask = PSW32_MASK_USER;
703
704 mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
705 /* Build a 64 bit psw mask from 31 bit mask. */
706 if ((tmp ^ PSW32_USER_BITS) & ~mask)
707 /* Invalid psw mask. */
708 return -EINVAL;
709 if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
710 /* Invalid address-space-control bits */
711 return -EINVAL;
712 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
713 (regs->psw.mask & PSW_MASK_BA) |
714 (__u64)(tmp & mask) << 32;
715 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
716 /* Build a 64 bit psw address from 31 bit address. */
717 regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
718 /* Transfer 31 bit amode bit to psw mask. */
719 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
720 (__u64)(tmp & PSW32_ADDR_AMODE);
721 } else {
722 /* gpr 0-15 */
723 *(__u32*)((addr_t) ®s->psw + addr*2 + 4) = tmp;
724 }
725 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
726 /*
727 * access registers are stored in the thread structure
728 */
729 offset = addr - (addr_t) &dummy32->regs.acrs;
730 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
731
732 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
733 /*
734 * orig_gpr2 is stored on the kernel stack
735 */
736 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
737
738 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
739 /*
740 * prevent writess of padding hole between
741 * orig_gpr2 and fp_regs on s390.
742 */
743 return 0;
744
745 } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
746 /*
747 * floating point control reg. is in the thread structure
748 */
749 if (test_fp_ctl(tmp))
750 return -EINVAL;
751 child->thread.fpu.fpc = data;
752
753 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
754 /*
755 * floating point regs. are either in child->thread.fpu
756 * or the child->thread.fpu.vxrs array
757 */
758 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
759 if (MACHINE_HAS_VX)
760 *(__u32 *)((addr_t)
761 child->thread.fpu.vxrs + 2*offset) = tmp;
762 else
763 *(__u32 *)((addr_t)
764 child->thread.fpu.fprs + offset) = tmp;
765
766 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
767 /*
768 * Handle access to the per_info structure.
769 */
770 addr -= (addr_t) &dummy32->regs.per_info;
771 __poke_user_per_compat(child, addr, data);
772 }
773
774 return 0;
775}
776
777static int poke_user_compat(struct task_struct *child,
778 addr_t addr, addr_t data)
779{
780 if (!is_compat_task() || (addr & 3) ||
781 addr > sizeof(struct compat_user) - 3)
782 return -EIO;
783
784 return __poke_user_compat(child, addr, data);
785}
786
787long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
788 compat_ulong_t caddr, compat_ulong_t cdata)
789{
790 unsigned long addr = caddr;
791 unsigned long data = cdata;
792 compat_ptrace_area parea;
793 int copied, ret;
794
795 switch (request) {
796 case PTRACE_PEEKUSR:
797 /* read the word at location addr in the USER area. */
798 return peek_user_compat(child, addr, data);
799
800 case PTRACE_POKEUSR:
801 /* write the word at location addr in the USER area */
802 return poke_user_compat(child, addr, data);
803
804 case PTRACE_PEEKUSR_AREA:
805 case PTRACE_POKEUSR_AREA:
806 if (copy_from_user(&parea, (void __force __user *) addr,
807 sizeof(parea)))
808 return -EFAULT;
809 addr = parea.kernel_addr;
810 data = parea.process_addr;
811 copied = 0;
812 while (copied < parea.len) {
813 if (request == PTRACE_PEEKUSR_AREA)
814 ret = peek_user_compat(child, addr, data);
815 else {
816 __u32 utmp;
817 if (get_user(utmp,
818 (__u32 __force __user *) data))
819 return -EFAULT;
820 ret = poke_user_compat(child, addr, utmp);
821 }
822 if (ret)
823 return ret;
824 addr += sizeof(unsigned int);
825 data += sizeof(unsigned int);
826 copied += sizeof(unsigned int);
827 }
828 return 0;
829 case PTRACE_GET_LAST_BREAK:
830 put_user(child->thread.last_break,
831 (unsigned int __user *) data);
832 return 0;
833 }
834 return compat_ptrace_request(child, request, addr, data);
835}
836#endif
837
838asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
839{
840 unsigned long mask = -1UL;
841
842 /*
843 * The sysc_tracesys code in entry.S stored the system
844 * call number to gprs[2].
845 */
846 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
847 (tracehook_report_syscall_entry(regs) ||
848 regs->gprs[2] >= NR_syscalls)) {
849 /*
850 * Tracing decided this syscall should not happen or the
851 * debugger stored an invalid system call number. Skip
852 * the system call and the system call restart handling.
853 */
854 clear_pt_regs_flag(regs, PIF_SYSCALL);
855 return -1;
856 }
857
858 /* Do the secure computing check after ptrace. */
859 if (secure_computing(NULL)) {
860 /* seccomp failures shouldn't expose any additional code. */
861 return -1;
862 }
863
864 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
865 trace_sys_enter(regs, regs->gprs[2]);
866
867 if (is_compat_task())
868 mask = 0xffffffff;
869
870 audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
871 regs->gprs[3] &mask, regs->gprs[4] &mask,
872 regs->gprs[5] &mask);
873
874 return regs->gprs[2];
875}
876
877asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
878{
879 audit_syscall_exit(regs);
880
881 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
882 trace_sys_exit(regs, regs->gprs[2]);
883
884 if (test_thread_flag(TIF_SYSCALL_TRACE))
885 tracehook_report_syscall_exit(regs, 0);
886}
887
888/*
889 * user_regset definitions.
890 */
891
892static int s390_regs_get(struct task_struct *target,
893 const struct user_regset *regset,
894 unsigned int pos, unsigned int count,
895 void *kbuf, void __user *ubuf)
896{
897 if (target == current)
898 save_access_regs(target->thread.acrs);
899
900 if (kbuf) {
901 unsigned long *k = kbuf;
902 while (count > 0) {
903 *k++ = __peek_user(target, pos);
904 count -= sizeof(*k);
905 pos += sizeof(*k);
906 }
907 } else {
908 unsigned long __user *u = ubuf;
909 while (count > 0) {
910 if (__put_user(__peek_user(target, pos), u++))
911 return -EFAULT;
912 count -= sizeof(*u);
913 pos += sizeof(*u);
914 }
915 }
916 return 0;
917}
918
919static int s390_regs_set(struct task_struct *target,
920 const struct user_regset *regset,
921 unsigned int pos, unsigned int count,
922 const void *kbuf, const void __user *ubuf)
923{
924 int rc = 0;
925
926 if (target == current)
927 save_access_regs(target->thread.acrs);
928
929 if (kbuf) {
930 const unsigned long *k = kbuf;
931 while (count > 0 && !rc) {
932 rc = __poke_user(target, pos, *k++);
933 count -= sizeof(*k);
934 pos += sizeof(*k);
935 }
936 } else {
937 const unsigned long __user *u = ubuf;
938 while (count > 0 && !rc) {
939 unsigned long word;
940 rc = __get_user(word, u++);
941 if (rc)
942 break;
943 rc = __poke_user(target, pos, word);
944 count -= sizeof(*u);
945 pos += sizeof(*u);
946 }
947 }
948
949 if (rc == 0 && target == current)
950 restore_access_regs(target->thread.acrs);
951
952 return rc;
953}
954
955static int s390_fpregs_get(struct task_struct *target,
956 const struct user_regset *regset, unsigned int pos,
957 unsigned int count, void *kbuf, void __user *ubuf)
958{
959 _s390_fp_regs fp_regs;
960
961 if (target == current)
962 save_fpu_regs();
963
964 fp_regs.fpc = target->thread.fpu.fpc;
965 fpregs_store(&fp_regs, &target->thread.fpu);
966
967 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
968 &fp_regs, 0, -1);
969}
970
971static int s390_fpregs_set(struct task_struct *target,
972 const struct user_regset *regset, unsigned int pos,
973 unsigned int count, const void *kbuf,
974 const void __user *ubuf)
975{
976 int rc = 0;
977 freg_t fprs[__NUM_FPRS];
978
979 if (target == current)
980 save_fpu_regs();
981
982 if (MACHINE_HAS_VX)
983 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
984 else
985 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
986
987 /* If setting FPC, must validate it first. */
988 if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
989 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
990 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
991 0, offsetof(s390_fp_regs, fprs));
992 if (rc)
993 return rc;
994 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
995 return -EINVAL;
996 target->thread.fpu.fpc = ufpc[0];
997 }
998
999 if (rc == 0 && count > 0)
1000 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1001 fprs, offsetof(s390_fp_regs, fprs), -1);
1002 if (rc)
1003 return rc;
1004
1005 if (MACHINE_HAS_VX)
1006 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1007 else
1008 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1009
1010 return rc;
1011}
1012
1013static int s390_last_break_get(struct task_struct *target,
1014 const struct user_regset *regset,
1015 unsigned int pos, unsigned int count,
1016 void *kbuf, void __user *ubuf)
1017{
1018 if (count > 0) {
1019 if (kbuf) {
1020 unsigned long *k = kbuf;
1021 *k = target->thread.last_break;
1022 } else {
1023 unsigned long __user *u = ubuf;
1024 if (__put_user(target->thread.last_break, u))
1025 return -EFAULT;
1026 }
1027 }
1028 return 0;
1029}
1030
1031static int s390_last_break_set(struct task_struct *target,
1032 const struct user_regset *regset,
1033 unsigned int pos, unsigned int count,
1034 const void *kbuf, const void __user *ubuf)
1035{
1036 return 0;
1037}
1038
1039static int s390_tdb_get(struct task_struct *target,
1040 const struct user_regset *regset,
1041 unsigned int pos, unsigned int count,
1042 void *kbuf, void __user *ubuf)
1043{
1044 struct pt_regs *regs = task_pt_regs(target);
1045 unsigned char *data;
1046
1047 if (!(regs->int_code & 0x200))
1048 return -ENODATA;
1049 data = target->thread.trap_tdb;
1050 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1051}
1052
1053static int s390_tdb_set(struct task_struct *target,
1054 const struct user_regset *regset,
1055 unsigned int pos, unsigned int count,
1056 const void *kbuf, const void __user *ubuf)
1057{
1058 return 0;
1059}
1060
1061static int s390_vxrs_low_get(struct task_struct *target,
1062 const struct user_regset *regset,
1063 unsigned int pos, unsigned int count,
1064 void *kbuf, void __user *ubuf)
1065{
1066 __u64 vxrs[__NUM_VXRS_LOW];
1067 int i;
1068
1069 if (!MACHINE_HAS_VX)
1070 return -ENODEV;
1071 if (target == current)
1072 save_fpu_regs();
1073 for (i = 0; i < __NUM_VXRS_LOW; i++)
1074 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1075 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1076}
1077
1078static int s390_vxrs_low_set(struct task_struct *target,
1079 const struct user_regset *regset,
1080 unsigned int pos, unsigned int count,
1081 const void *kbuf, const void __user *ubuf)
1082{
1083 __u64 vxrs[__NUM_VXRS_LOW];
1084 int i, rc;
1085
1086 if (!MACHINE_HAS_VX)
1087 return -ENODEV;
1088 if (target == current)
1089 save_fpu_regs();
1090
1091 for (i = 0; i < __NUM_VXRS_LOW; i++)
1092 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1093
1094 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1095 if (rc == 0)
1096 for (i = 0; i < __NUM_VXRS_LOW; i++)
1097 *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1098
1099 return rc;
1100}
1101
1102static int s390_vxrs_high_get(struct task_struct *target,
1103 const struct user_regset *regset,
1104 unsigned int pos, unsigned int count,
1105 void *kbuf, void __user *ubuf)
1106{
1107 __vector128 vxrs[__NUM_VXRS_HIGH];
1108
1109 if (!MACHINE_HAS_VX)
1110 return -ENODEV;
1111 if (target == current)
1112 save_fpu_regs();
1113 memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1114
1115 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1116}
1117
1118static int s390_vxrs_high_set(struct task_struct *target,
1119 const struct user_regset *regset,
1120 unsigned int pos, unsigned int count,
1121 const void *kbuf, const void __user *ubuf)
1122{
1123 int rc;
1124
1125 if (!MACHINE_HAS_VX)
1126 return -ENODEV;
1127 if (target == current)
1128 save_fpu_regs();
1129
1130 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1131 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1132 return rc;
1133}
1134
1135static int s390_system_call_get(struct task_struct *target,
1136 const struct user_regset *regset,
1137 unsigned int pos, unsigned int count,
1138 void *kbuf, void __user *ubuf)
1139{
1140 unsigned int *data = &target->thread.system_call;
1141 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1142 data, 0, sizeof(unsigned int));
1143}
1144
1145static int s390_system_call_set(struct task_struct *target,
1146 const struct user_regset *regset,
1147 unsigned int pos, unsigned int count,
1148 const void *kbuf, const void __user *ubuf)
1149{
1150 unsigned int *data = &target->thread.system_call;
1151 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1152 data, 0, sizeof(unsigned int));
1153}
1154
1155static int s390_gs_cb_get(struct task_struct *target,
1156 const struct user_regset *regset,
1157 unsigned int pos, unsigned int count,
1158 void *kbuf, void __user *ubuf)
1159{
1160 struct gs_cb *data = target->thread.gs_cb;
1161
1162 if (!MACHINE_HAS_GS)
1163 return -ENODEV;
1164 if (!data)
1165 return -ENODATA;
1166 if (target == current)
1167 save_gs_cb(data);
1168 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1169 data, 0, sizeof(struct gs_cb));
1170}
1171
1172static int s390_gs_cb_set(struct task_struct *target,
1173 const struct user_regset *regset,
1174 unsigned int pos, unsigned int count,
1175 const void *kbuf, const void __user *ubuf)
1176{
1177 struct gs_cb gs_cb = { }, *data = NULL;
1178 int rc;
1179
1180 if (!MACHINE_HAS_GS)
1181 return -ENODEV;
1182 if (!target->thread.gs_cb) {
1183 data = kzalloc(sizeof(*data), GFP_KERNEL);
1184 if (!data)
1185 return -ENOMEM;
1186 }
1187 if (!target->thread.gs_cb)
1188 gs_cb.gsd = 25;
1189 else if (target == current)
1190 save_gs_cb(&gs_cb);
1191 else
1192 gs_cb = *target->thread.gs_cb;
1193 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1194 &gs_cb, 0, sizeof(gs_cb));
1195 if (rc) {
1196 kfree(data);
1197 return -EFAULT;
1198 }
1199 preempt_disable();
1200 if (!target->thread.gs_cb)
1201 target->thread.gs_cb = data;
1202 *target->thread.gs_cb = gs_cb;
1203 if (target == current) {
1204 __ctl_set_bit(2, 4);
1205 restore_gs_cb(target->thread.gs_cb);
1206 }
1207 preempt_enable();
1208 return rc;
1209}
1210
1211static int s390_gs_bc_get(struct task_struct *target,
1212 const struct user_regset *regset,
1213 unsigned int pos, unsigned int count,
1214 void *kbuf, void __user *ubuf)
1215{
1216 struct gs_cb *data = target->thread.gs_bc_cb;
1217
1218 if (!MACHINE_HAS_GS)
1219 return -ENODEV;
1220 if (!data)
1221 return -ENODATA;
1222 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1223 data, 0, sizeof(struct gs_cb));
1224}
1225
1226static int s390_gs_bc_set(struct task_struct *target,
1227 const struct user_regset *regset,
1228 unsigned int pos, unsigned int count,
1229 const void *kbuf, const void __user *ubuf)
1230{
1231 struct gs_cb *data = target->thread.gs_bc_cb;
1232
1233 if (!MACHINE_HAS_GS)
1234 return -ENODEV;
1235 if (!data) {
1236 data = kzalloc(sizeof(*data), GFP_KERNEL);
1237 if (!data)
1238 return -ENOMEM;
1239 target->thread.gs_bc_cb = data;
1240 }
1241 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1242 data, 0, sizeof(struct gs_cb));
1243}
1244
1245static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1246{
1247 return (cb->rca & 0x1f) == 0 &&
1248 (cb->roa & 0xfff) == 0 &&
1249 (cb->rla & 0xfff) == 0xfff &&
1250 cb->s == 1 &&
1251 cb->k == 1 &&
1252 cb->h == 0 &&
1253 cb->reserved1 == 0 &&
1254 cb->ps == 1 &&
1255 cb->qs == 0 &&
1256 cb->pc == 1 &&
1257 cb->qc == 0 &&
1258 cb->reserved2 == 0 &&
1259 cb->key == PAGE_DEFAULT_KEY &&
1260 cb->reserved3 == 0 &&
1261 cb->reserved4 == 0 &&
1262 cb->reserved5 == 0 &&
1263 cb->reserved6 == 0 &&
1264 cb->reserved7 == 0 &&
1265 cb->reserved8 == 0 &&
1266 cb->rla >= cb->roa &&
1267 cb->rca >= cb->roa &&
1268 cb->rca <= cb->rla+1 &&
1269 cb->m < 3;
1270}
1271
1272static int s390_runtime_instr_get(struct task_struct *target,
1273 const struct user_regset *regset,
1274 unsigned int pos, unsigned int count,
1275 void *kbuf, void __user *ubuf)
1276{
1277 struct runtime_instr_cb *data = target->thread.ri_cb;
1278
1279 if (!test_facility(64))
1280 return -ENODEV;
1281 if (!data)
1282 return -ENODATA;
1283
1284 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1285 data, 0, sizeof(struct runtime_instr_cb));
1286}
1287
1288static int s390_runtime_instr_set(struct task_struct *target,
1289 const struct user_regset *regset,
1290 unsigned int pos, unsigned int count,
1291 const void *kbuf, const void __user *ubuf)
1292{
1293 struct runtime_instr_cb ri_cb = { }, *data = NULL;
1294 int rc;
1295
1296 if (!test_facility(64))
1297 return -ENODEV;
1298
1299 if (!target->thread.ri_cb) {
1300 data = kzalloc(sizeof(*data), GFP_KERNEL);
1301 if (!data)
1302 return -ENOMEM;
1303 }
1304
1305 if (target->thread.ri_cb) {
1306 if (target == current)
1307 store_runtime_instr_cb(&ri_cb);
1308 else
1309 ri_cb = *target->thread.ri_cb;
1310 }
1311
1312 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1313 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1314 if (rc) {
1315 kfree(data);
1316 return -EFAULT;
1317 }
1318
1319 if (!is_ri_cb_valid(&ri_cb)) {
1320 kfree(data);
1321 return -EINVAL;
1322 }
1323
1324 preempt_disable();
1325 if (!target->thread.ri_cb)
1326 target->thread.ri_cb = data;
1327 *target->thread.ri_cb = ri_cb;
1328 if (target == current)
1329 load_runtime_instr_cb(target->thread.ri_cb);
1330 preempt_enable();
1331
1332 return 0;
1333}
1334
1335static const struct user_regset s390_regsets[] = {
1336 {
1337 .core_note_type = NT_PRSTATUS,
1338 .n = sizeof(s390_regs) / sizeof(long),
1339 .size = sizeof(long),
1340 .align = sizeof(long),
1341 .get = s390_regs_get,
1342 .set = s390_regs_set,
1343 },
1344 {
1345 .core_note_type = NT_PRFPREG,
1346 .n = sizeof(s390_fp_regs) / sizeof(long),
1347 .size = sizeof(long),
1348 .align = sizeof(long),
1349 .get = s390_fpregs_get,
1350 .set = s390_fpregs_set,
1351 },
1352 {
1353 .core_note_type = NT_S390_SYSTEM_CALL,
1354 .n = 1,
1355 .size = sizeof(unsigned int),
1356 .align = sizeof(unsigned int),
1357 .get = s390_system_call_get,
1358 .set = s390_system_call_set,
1359 },
1360 {
1361 .core_note_type = NT_S390_LAST_BREAK,
1362 .n = 1,
1363 .size = sizeof(long),
1364 .align = sizeof(long),
1365 .get = s390_last_break_get,
1366 .set = s390_last_break_set,
1367 },
1368 {
1369 .core_note_type = NT_S390_TDB,
1370 .n = 1,
1371 .size = 256,
1372 .align = 1,
1373 .get = s390_tdb_get,
1374 .set = s390_tdb_set,
1375 },
1376 {
1377 .core_note_type = NT_S390_VXRS_LOW,
1378 .n = __NUM_VXRS_LOW,
1379 .size = sizeof(__u64),
1380 .align = sizeof(__u64),
1381 .get = s390_vxrs_low_get,
1382 .set = s390_vxrs_low_set,
1383 },
1384 {
1385 .core_note_type = NT_S390_VXRS_HIGH,
1386 .n = __NUM_VXRS_HIGH,
1387 .size = sizeof(__vector128),
1388 .align = sizeof(__vector128),
1389 .get = s390_vxrs_high_get,
1390 .set = s390_vxrs_high_set,
1391 },
1392 {
1393 .core_note_type = NT_S390_GS_CB,
1394 .n = sizeof(struct gs_cb) / sizeof(__u64),
1395 .size = sizeof(__u64),
1396 .align = sizeof(__u64),
1397 .get = s390_gs_cb_get,
1398 .set = s390_gs_cb_set,
1399 },
1400 {
1401 .core_note_type = NT_S390_GS_BC,
1402 .n = sizeof(struct gs_cb) / sizeof(__u64),
1403 .size = sizeof(__u64),
1404 .align = sizeof(__u64),
1405 .get = s390_gs_bc_get,
1406 .set = s390_gs_bc_set,
1407 },
1408 {
1409 .core_note_type = NT_S390_RI_CB,
1410 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1411 .size = sizeof(__u64),
1412 .align = sizeof(__u64),
1413 .get = s390_runtime_instr_get,
1414 .set = s390_runtime_instr_set,
1415 },
1416};
1417
1418static const struct user_regset_view user_s390_view = {
1419 .name = UTS_MACHINE,
1420 .e_machine = EM_S390,
1421 .regsets = s390_regsets,
1422 .n = ARRAY_SIZE(s390_regsets)
1423};
1424
1425#ifdef CONFIG_COMPAT
1426static int s390_compat_regs_get(struct task_struct *target,
1427 const struct user_regset *regset,
1428 unsigned int pos, unsigned int count,
1429 void *kbuf, void __user *ubuf)
1430{
1431 if (target == current)
1432 save_access_regs(target->thread.acrs);
1433
1434 if (kbuf) {
1435 compat_ulong_t *k = kbuf;
1436 while (count > 0) {
1437 *k++ = __peek_user_compat(target, pos);
1438 count -= sizeof(*k);
1439 pos += sizeof(*k);
1440 }
1441 } else {
1442 compat_ulong_t __user *u = ubuf;
1443 while (count > 0) {
1444 if (__put_user(__peek_user_compat(target, pos), u++))
1445 return -EFAULT;
1446 count -= sizeof(*u);
1447 pos += sizeof(*u);
1448 }
1449 }
1450 return 0;
1451}
1452
1453static int s390_compat_regs_set(struct task_struct *target,
1454 const struct user_regset *regset,
1455 unsigned int pos, unsigned int count,
1456 const void *kbuf, const void __user *ubuf)
1457{
1458 int rc = 0;
1459
1460 if (target == current)
1461 save_access_regs(target->thread.acrs);
1462
1463 if (kbuf) {
1464 const compat_ulong_t *k = kbuf;
1465 while (count > 0 && !rc) {
1466 rc = __poke_user_compat(target, pos, *k++);
1467 count -= sizeof(*k);
1468 pos += sizeof(*k);
1469 }
1470 } else {
1471 const compat_ulong_t __user *u = ubuf;
1472 while (count > 0 && !rc) {
1473 compat_ulong_t word;
1474 rc = __get_user(word, u++);
1475 if (rc)
1476 break;
1477 rc = __poke_user_compat(target, pos, word);
1478 count -= sizeof(*u);
1479 pos += sizeof(*u);
1480 }
1481 }
1482
1483 if (rc == 0 && target == current)
1484 restore_access_regs(target->thread.acrs);
1485
1486 return rc;
1487}
1488
1489static int s390_compat_regs_high_get(struct task_struct *target,
1490 const struct user_regset *regset,
1491 unsigned int pos, unsigned int count,
1492 void *kbuf, void __user *ubuf)
1493{
1494 compat_ulong_t *gprs_high;
1495
1496 gprs_high = (compat_ulong_t *)
1497 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1498 if (kbuf) {
1499 compat_ulong_t *k = kbuf;
1500 while (count > 0) {
1501 *k++ = *gprs_high;
1502 gprs_high += 2;
1503 count -= sizeof(*k);
1504 }
1505 } else {
1506 compat_ulong_t __user *u = ubuf;
1507 while (count > 0) {
1508 if (__put_user(*gprs_high, u++))
1509 return -EFAULT;
1510 gprs_high += 2;
1511 count -= sizeof(*u);
1512 }
1513 }
1514 return 0;
1515}
1516
1517static int s390_compat_regs_high_set(struct task_struct *target,
1518 const struct user_regset *regset,
1519 unsigned int pos, unsigned int count,
1520 const void *kbuf, const void __user *ubuf)
1521{
1522 compat_ulong_t *gprs_high;
1523 int rc = 0;
1524
1525 gprs_high = (compat_ulong_t *)
1526 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1527 if (kbuf) {
1528 const compat_ulong_t *k = kbuf;
1529 while (count > 0) {
1530 *gprs_high = *k++;
1531 *gprs_high += 2;
1532 count -= sizeof(*k);
1533 }
1534 } else {
1535 const compat_ulong_t __user *u = ubuf;
1536 while (count > 0 && !rc) {
1537 unsigned long word;
1538 rc = __get_user(word, u++);
1539 if (rc)
1540 break;
1541 *gprs_high = word;
1542 *gprs_high += 2;
1543 count -= sizeof(*u);
1544 }
1545 }
1546
1547 return rc;
1548}
1549
1550static int s390_compat_last_break_get(struct task_struct *target,
1551 const struct user_regset *regset,
1552 unsigned int pos, unsigned int count,
1553 void *kbuf, void __user *ubuf)
1554{
1555 compat_ulong_t last_break;
1556
1557 if (count > 0) {
1558 last_break = target->thread.last_break;
1559 if (kbuf) {
1560 unsigned long *k = kbuf;
1561 *k = last_break;
1562 } else {
1563 unsigned long __user *u = ubuf;
1564 if (__put_user(last_break, u))
1565 return -EFAULT;
1566 }
1567 }
1568 return 0;
1569}
1570
1571static int s390_compat_last_break_set(struct task_struct *target,
1572 const struct user_regset *regset,
1573 unsigned int pos, unsigned int count,
1574 const void *kbuf, const void __user *ubuf)
1575{
1576 return 0;
1577}
1578
1579static const struct user_regset s390_compat_regsets[] = {
1580 {
1581 .core_note_type = NT_PRSTATUS,
1582 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1583 .size = sizeof(compat_long_t),
1584 .align = sizeof(compat_long_t),
1585 .get = s390_compat_regs_get,
1586 .set = s390_compat_regs_set,
1587 },
1588 {
1589 .core_note_type = NT_PRFPREG,
1590 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1591 .size = sizeof(compat_long_t),
1592 .align = sizeof(compat_long_t),
1593 .get = s390_fpregs_get,
1594 .set = s390_fpregs_set,
1595 },
1596 {
1597 .core_note_type = NT_S390_SYSTEM_CALL,
1598 .n = 1,
1599 .size = sizeof(compat_uint_t),
1600 .align = sizeof(compat_uint_t),
1601 .get = s390_system_call_get,
1602 .set = s390_system_call_set,
1603 },
1604 {
1605 .core_note_type = NT_S390_LAST_BREAK,
1606 .n = 1,
1607 .size = sizeof(long),
1608 .align = sizeof(long),
1609 .get = s390_compat_last_break_get,
1610 .set = s390_compat_last_break_set,
1611 },
1612 {
1613 .core_note_type = NT_S390_TDB,
1614 .n = 1,
1615 .size = 256,
1616 .align = 1,
1617 .get = s390_tdb_get,
1618 .set = s390_tdb_set,
1619 },
1620 {
1621 .core_note_type = NT_S390_VXRS_LOW,
1622 .n = __NUM_VXRS_LOW,
1623 .size = sizeof(__u64),
1624 .align = sizeof(__u64),
1625 .get = s390_vxrs_low_get,
1626 .set = s390_vxrs_low_set,
1627 },
1628 {
1629 .core_note_type = NT_S390_VXRS_HIGH,
1630 .n = __NUM_VXRS_HIGH,
1631 .size = sizeof(__vector128),
1632 .align = sizeof(__vector128),
1633 .get = s390_vxrs_high_get,
1634 .set = s390_vxrs_high_set,
1635 },
1636 {
1637 .core_note_type = NT_S390_HIGH_GPRS,
1638 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1639 .size = sizeof(compat_long_t),
1640 .align = sizeof(compat_long_t),
1641 .get = s390_compat_regs_high_get,
1642 .set = s390_compat_regs_high_set,
1643 },
1644 {
1645 .core_note_type = NT_S390_GS_CB,
1646 .n = sizeof(struct gs_cb) / sizeof(__u64),
1647 .size = sizeof(__u64),
1648 .align = sizeof(__u64),
1649 .get = s390_gs_cb_get,
1650 .set = s390_gs_cb_set,
1651 },
1652 {
1653 .core_note_type = NT_S390_GS_BC,
1654 .n = sizeof(struct gs_cb) / sizeof(__u64),
1655 .size = sizeof(__u64),
1656 .align = sizeof(__u64),
1657 .get = s390_gs_bc_get,
1658 .set = s390_gs_bc_set,
1659 },
1660 {
1661 .core_note_type = NT_S390_RI_CB,
1662 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1663 .size = sizeof(__u64),
1664 .align = sizeof(__u64),
1665 .get = s390_runtime_instr_get,
1666 .set = s390_runtime_instr_set,
1667 },
1668};
1669
1670static const struct user_regset_view user_s390_compat_view = {
1671 .name = "s390",
1672 .e_machine = EM_S390,
1673 .regsets = s390_compat_regsets,
1674 .n = ARRAY_SIZE(s390_compat_regsets)
1675};
1676#endif
1677
1678const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1679{
1680#ifdef CONFIG_COMPAT
1681 if (test_tsk_thread_flag(task, TIF_31BIT))
1682 return &user_s390_compat_view;
1683#endif
1684 return &user_s390_view;
1685}
1686
1687static const char *gpr_names[NUM_GPRS] = {
1688 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
1689 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1690};
1691
1692unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1693{
1694 if (offset >= NUM_GPRS)
1695 return 0;
1696 return regs->gprs[offset];
1697}
1698
1699int regs_query_register_offset(const char *name)
1700{
1701 unsigned long offset;
1702
1703 if (!name || *name != 'r')
1704 return -EINVAL;
1705 if (kstrtoul(name + 1, 10, &offset))
1706 return -EINVAL;
1707 if (offset >= NUM_GPRS)
1708 return -EINVAL;
1709 return offset;
1710}
1711
1712const char *regs_query_register_name(unsigned int offset)
1713{
1714 if (offset >= NUM_GPRS)
1715 return NULL;
1716 return gpr_names[offset];
1717}
1718
1719static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1720{
1721 unsigned long ksp = kernel_stack_pointer(regs);
1722
1723 return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1724}
1725
1726/**
1727 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1728 * @regs:pt_regs which contains kernel stack pointer.
1729 * @n:stack entry number.
1730 *
1731 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1732 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1733 * this returns 0.
1734 */
1735unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1736{
1737 unsigned long addr;
1738
1739 addr = kernel_stack_pointer(regs) + n * sizeof(long);
1740 if (!regs_within_kernel_stack(regs, addr))
1741 return 0;
1742 return *(unsigned long *)addr;
1743}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Ptrace user space interface.
4 *
5 * Copyright IBM Corp. 1999, 2010
6 * Author(s): Denis Joseph Barrow
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
8 */
9
10#include "asm/ptrace.h"
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/sched/task_stack.h>
14#include <linux/mm.h>
15#include <linux/smp.h>
16#include <linux/errno.h>
17#include <linux/ptrace.h>
18#include <linux/user.h>
19#include <linux/security.h>
20#include <linux/audit.h>
21#include <linux/signal.h>
22#include <linux/elf.h>
23#include <linux/regset.h>
24#include <linux/tracehook.h>
25#include <linux/seccomp.h>
26#include <linux/compat.h>
27#include <trace/syscall.h>
28#include <asm/page.h>
29#include <linux/uaccess.h>
30#include <asm/unistd.h>
31#include <asm/switch_to.h>
32#include <asm/runtime_instr.h>
33#include <asm/facility.h>
34
35#include "entry.h"
36
37#ifdef CONFIG_COMPAT
38#include "compat_ptrace.h"
39#endif
40
41void update_cr_regs(struct task_struct *task)
42{
43 struct pt_regs *regs = task_pt_regs(task);
44 struct thread_struct *thread = &task->thread;
45 struct per_regs old, new;
46 union ctlreg0 cr0_old, cr0_new;
47 union ctlreg2 cr2_old, cr2_new;
48 int cr0_changed, cr2_changed;
49
50 __ctl_store(cr0_old.val, 0, 0);
51 __ctl_store(cr2_old.val, 2, 2);
52 cr0_new = cr0_old;
53 cr2_new = cr2_old;
54 /* Take care of the enable/disable of transactional execution. */
55 if (MACHINE_HAS_TE) {
56 /* Set or clear transaction execution TXC bit 8. */
57 cr0_new.tcx = 1;
58 if (task->thread.per_flags & PER_FLAG_NO_TE)
59 cr0_new.tcx = 0;
60 /* Set or clear transaction execution TDC bits 62 and 63. */
61 cr2_new.tdc = 0;
62 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
63 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
64 cr2_new.tdc = 1;
65 else
66 cr2_new.tdc = 2;
67 }
68 }
69 /* Take care of enable/disable of guarded storage. */
70 if (MACHINE_HAS_GS) {
71 cr2_new.gse = 0;
72 if (task->thread.gs_cb)
73 cr2_new.gse = 1;
74 }
75 /* Load control register 0/2 iff changed */
76 cr0_changed = cr0_new.val != cr0_old.val;
77 cr2_changed = cr2_new.val != cr2_old.val;
78 if (cr0_changed)
79 __ctl_load(cr0_new.val, 0, 0);
80 if (cr2_changed)
81 __ctl_load(cr2_new.val, 2, 2);
82 /* Copy user specified PER registers */
83 new.control = thread->per_user.control;
84 new.start = thread->per_user.start;
85 new.end = thread->per_user.end;
86
87 /* merge TIF_SINGLE_STEP into user specified PER registers. */
88 if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
89 test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
90 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
91 new.control |= PER_EVENT_BRANCH;
92 else
93 new.control |= PER_EVENT_IFETCH;
94 new.control |= PER_CONTROL_SUSPENSION;
95 new.control |= PER_EVENT_TRANSACTION_END;
96 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
97 new.control |= PER_EVENT_IFETCH;
98 new.start = 0;
99 new.end = -1UL;
100 }
101
102 /* Take care of the PER enablement bit in the PSW. */
103 if (!(new.control & PER_EVENT_MASK)) {
104 regs->psw.mask &= ~PSW_MASK_PER;
105 return;
106 }
107 regs->psw.mask |= PSW_MASK_PER;
108 __ctl_store(old, 9, 11);
109 if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
110 __ctl_load(new, 9, 11);
111}
112
113void user_enable_single_step(struct task_struct *task)
114{
115 clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
116 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
117}
118
119void user_disable_single_step(struct task_struct *task)
120{
121 clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
122 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
123}
124
125void user_enable_block_step(struct task_struct *task)
126{
127 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
128 set_tsk_thread_flag(task, TIF_BLOCK_STEP);
129}
130
131/*
132 * Called by kernel/ptrace.c when detaching..
133 *
134 * Clear all debugging related fields.
135 */
136void ptrace_disable(struct task_struct *task)
137{
138 memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
139 memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
140 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
141 clear_tsk_thread_flag(task, TIF_PER_TRAP);
142 task->thread.per_flags = 0;
143}
144
145#define __ADDR_MASK 7
146
147static inline unsigned long __peek_user_per(struct task_struct *child,
148 addr_t addr)
149{
150 struct per_struct_kernel *dummy = NULL;
151
152 if (addr == (addr_t) &dummy->cr9)
153 /* Control bits of the active per set. */
154 return test_thread_flag(TIF_SINGLE_STEP) ?
155 PER_EVENT_IFETCH : child->thread.per_user.control;
156 else if (addr == (addr_t) &dummy->cr10)
157 /* Start address of the active per set. */
158 return test_thread_flag(TIF_SINGLE_STEP) ?
159 0 : child->thread.per_user.start;
160 else if (addr == (addr_t) &dummy->cr11)
161 /* End address of the active per set. */
162 return test_thread_flag(TIF_SINGLE_STEP) ?
163 -1UL : child->thread.per_user.end;
164 else if (addr == (addr_t) &dummy->bits)
165 /* Single-step bit. */
166 return test_thread_flag(TIF_SINGLE_STEP) ?
167 (1UL << (BITS_PER_LONG - 1)) : 0;
168 else if (addr == (addr_t) &dummy->starting_addr)
169 /* Start address of the user specified per set. */
170 return child->thread.per_user.start;
171 else if (addr == (addr_t) &dummy->ending_addr)
172 /* End address of the user specified per set. */
173 return child->thread.per_user.end;
174 else if (addr == (addr_t) &dummy->perc_atmid)
175 /* PER code, ATMID and AI of the last PER trap */
176 return (unsigned long)
177 child->thread.per_event.cause << (BITS_PER_LONG - 16);
178 else if (addr == (addr_t) &dummy->address)
179 /* Address of the last PER trap */
180 return child->thread.per_event.address;
181 else if (addr == (addr_t) &dummy->access_id)
182 /* Access id of the last PER trap */
183 return (unsigned long)
184 child->thread.per_event.paid << (BITS_PER_LONG - 8);
185 return 0;
186}
187
188/*
189 * Read the word at offset addr from the user area of a process. The
190 * trouble here is that the information is littered over different
191 * locations. The process registers are found on the kernel stack,
192 * the floating point stuff and the trace settings are stored in
193 * the task structure. In addition the different structures in
194 * struct user contain pad bytes that should be read as zeroes.
195 * Lovely...
196 */
197static unsigned long __peek_user(struct task_struct *child, addr_t addr)
198{
199 struct user *dummy = NULL;
200 addr_t offset, tmp;
201
202 if (addr < (addr_t) &dummy->regs.acrs) {
203 /*
204 * psw and gprs are stored on the stack
205 */
206 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
207 if (addr == (addr_t) &dummy->regs.psw.mask) {
208 /* Return a clean psw mask. */
209 tmp &= PSW_MASK_USER | PSW_MASK_RI;
210 tmp |= PSW_USER_BITS;
211 }
212
213 } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
214 /*
215 * access registers are stored in the thread structure
216 */
217 offset = addr - (addr_t) &dummy->regs.acrs;
218 /*
219 * Very special case: old & broken 64 bit gdb reading
220 * from acrs[15]. Result is a 64 bit value. Read the
221 * 32 bit acrs[15] value and shift it by 32. Sick...
222 */
223 if (addr == (addr_t) &dummy->regs.acrs[15])
224 tmp = ((unsigned long) child->thread.acrs[15]) << 32;
225 else
226 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
227
228 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
229 /*
230 * orig_gpr2 is stored on the kernel stack
231 */
232 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
233
234 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
235 /*
236 * prevent reads of padding hole between
237 * orig_gpr2 and fp_regs on s390.
238 */
239 tmp = 0;
240
241 } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
242 /*
243 * floating point control reg. is in the thread structure
244 */
245 tmp = child->thread.fpu.fpc;
246 tmp <<= BITS_PER_LONG - 32;
247
248 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
249 /*
250 * floating point regs. are either in child->thread.fpu
251 * or the child->thread.fpu.vxrs array
252 */
253 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
254 if (MACHINE_HAS_VX)
255 tmp = *(addr_t *)
256 ((addr_t) child->thread.fpu.vxrs + 2*offset);
257 else
258 tmp = *(addr_t *)
259 ((addr_t) child->thread.fpu.fprs + offset);
260
261 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
262 /*
263 * Handle access to the per_info structure.
264 */
265 addr -= (addr_t) &dummy->regs.per_info;
266 tmp = __peek_user_per(child, addr);
267
268 } else
269 tmp = 0;
270
271 return tmp;
272}
273
274static int
275peek_user(struct task_struct *child, addr_t addr, addr_t data)
276{
277 addr_t tmp, mask;
278
279 /*
280 * Stupid gdb peeks/pokes the access registers in 64 bit with
281 * an alignment of 4. Programmers from hell...
282 */
283 mask = __ADDR_MASK;
284 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
285 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
286 mask = 3;
287 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
288 return -EIO;
289
290 tmp = __peek_user(child, addr);
291 return put_user(tmp, (addr_t __user *) data);
292}
293
294static inline void __poke_user_per(struct task_struct *child,
295 addr_t addr, addr_t data)
296{
297 struct per_struct_kernel *dummy = NULL;
298
299 /*
300 * There are only three fields in the per_info struct that the
301 * debugger user can write to.
302 * 1) cr9: the debugger wants to set a new PER event mask
303 * 2) starting_addr: the debugger wants to set a new starting
304 * address to use with the PER event mask.
305 * 3) ending_addr: the debugger wants to set a new ending
306 * address to use with the PER event mask.
307 * The user specified PER event mask and the start and end
308 * addresses are used only if single stepping is not in effect.
309 * Writes to any other field in per_info are ignored.
310 */
311 if (addr == (addr_t) &dummy->cr9)
312 /* PER event mask of the user specified per set. */
313 child->thread.per_user.control =
314 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
315 else if (addr == (addr_t) &dummy->starting_addr)
316 /* Starting address of the user specified per set. */
317 child->thread.per_user.start = data;
318 else if (addr == (addr_t) &dummy->ending_addr)
319 /* Ending address of the user specified per set. */
320 child->thread.per_user.end = data;
321}
322
323/*
324 * Write a word to the user area of a process at location addr. This
325 * operation does have an additional problem compared to peek_user.
326 * Stores to the program status word and on the floating point
327 * control register needs to get checked for validity.
328 */
329static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
330{
331 struct user *dummy = NULL;
332 addr_t offset;
333
334
335 if (addr < (addr_t) &dummy->regs.acrs) {
336 struct pt_regs *regs = task_pt_regs(child);
337 /*
338 * psw and gprs are stored on the stack
339 */
340 if (addr == (addr_t) &dummy->regs.psw.mask) {
341 unsigned long mask = PSW_MASK_USER;
342
343 mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
344 if ((data ^ PSW_USER_BITS) & ~mask)
345 /* Invalid psw mask. */
346 return -EINVAL;
347 if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
348 /* Invalid address-space-control bits */
349 return -EINVAL;
350 if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
351 /* Invalid addressing mode bits */
352 return -EINVAL;
353 }
354
355 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
356 addr == offsetof(struct user, regs.gprs[2])) {
357 struct pt_regs *regs = task_pt_regs(child);
358
359 regs->int_code = 0x20000 | (data & 0xffff);
360 }
361 *(addr_t *)((addr_t) ®s->psw + addr) = data;
362 } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
363 /*
364 * access registers are stored in the thread structure
365 */
366 offset = addr - (addr_t) &dummy->regs.acrs;
367 /*
368 * Very special case: old & broken 64 bit gdb writing
369 * to acrs[15] with a 64 bit value. Ignore the lower
370 * half of the value and write the upper 32 bit to
371 * acrs[15]. Sick...
372 */
373 if (addr == (addr_t) &dummy->regs.acrs[15])
374 child->thread.acrs[15] = (unsigned int) (data >> 32);
375 else
376 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
377
378 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
379 /*
380 * orig_gpr2 is stored on the kernel stack
381 */
382 task_pt_regs(child)->orig_gpr2 = data;
383
384 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
385 /*
386 * prevent writes of padding hole between
387 * orig_gpr2 and fp_regs on s390.
388 */
389 return 0;
390
391 } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
392 /*
393 * floating point control reg. is in the thread structure
394 */
395 if ((unsigned int) data != 0 ||
396 test_fp_ctl(data >> (BITS_PER_LONG - 32)))
397 return -EINVAL;
398 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
399
400 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
401 /*
402 * floating point regs. are either in child->thread.fpu
403 * or the child->thread.fpu.vxrs array
404 */
405 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
406 if (MACHINE_HAS_VX)
407 *(addr_t *)((addr_t)
408 child->thread.fpu.vxrs + 2*offset) = data;
409 else
410 *(addr_t *)((addr_t)
411 child->thread.fpu.fprs + offset) = data;
412
413 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
414 /*
415 * Handle access to the per_info structure.
416 */
417 addr -= (addr_t) &dummy->regs.per_info;
418 __poke_user_per(child, addr, data);
419
420 }
421
422 return 0;
423}
424
425static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
426{
427 addr_t mask;
428
429 /*
430 * Stupid gdb peeks/pokes the access registers in 64 bit with
431 * an alignment of 4. Programmers from hell indeed...
432 */
433 mask = __ADDR_MASK;
434 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
435 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
436 mask = 3;
437 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
438 return -EIO;
439
440 return __poke_user(child, addr, data);
441}
442
443long arch_ptrace(struct task_struct *child, long request,
444 unsigned long addr, unsigned long data)
445{
446 ptrace_area parea;
447 int copied, ret;
448
449 switch (request) {
450 case PTRACE_PEEKUSR:
451 /* read the word at location addr in the USER area. */
452 return peek_user(child, addr, data);
453
454 case PTRACE_POKEUSR:
455 /* write the word at location addr in the USER area */
456 return poke_user(child, addr, data);
457
458 case PTRACE_PEEKUSR_AREA:
459 case PTRACE_POKEUSR_AREA:
460 if (copy_from_user(&parea, (void __force __user *) addr,
461 sizeof(parea)))
462 return -EFAULT;
463 addr = parea.kernel_addr;
464 data = parea.process_addr;
465 copied = 0;
466 while (copied < parea.len) {
467 if (request == PTRACE_PEEKUSR_AREA)
468 ret = peek_user(child, addr, data);
469 else {
470 addr_t utmp;
471 if (get_user(utmp,
472 (addr_t __force __user *) data))
473 return -EFAULT;
474 ret = poke_user(child, addr, utmp);
475 }
476 if (ret)
477 return ret;
478 addr += sizeof(unsigned long);
479 data += sizeof(unsigned long);
480 copied += sizeof(unsigned long);
481 }
482 return 0;
483 case PTRACE_GET_LAST_BREAK:
484 put_user(child->thread.last_break,
485 (unsigned long __user *) data);
486 return 0;
487 case PTRACE_ENABLE_TE:
488 if (!MACHINE_HAS_TE)
489 return -EIO;
490 child->thread.per_flags &= ~PER_FLAG_NO_TE;
491 return 0;
492 case PTRACE_DISABLE_TE:
493 if (!MACHINE_HAS_TE)
494 return -EIO;
495 child->thread.per_flags |= PER_FLAG_NO_TE;
496 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
497 return 0;
498 case PTRACE_TE_ABORT_RAND:
499 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
500 return -EIO;
501 switch (data) {
502 case 0UL:
503 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
504 break;
505 case 1UL:
506 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
507 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
508 break;
509 case 2UL:
510 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
511 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
512 break;
513 default:
514 return -EINVAL;
515 }
516 return 0;
517 default:
518 return ptrace_request(child, request, addr, data);
519 }
520}
521
522#ifdef CONFIG_COMPAT
523/*
524 * Now the fun part starts... a 31 bit program running in the
525 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
526 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
527 * to handle, the difference to the 64 bit versions of the requests
528 * is that the access is done in multiples of 4 byte instead of
529 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
530 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
531 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
532 * is a 31 bit program too, the content of struct user can be
533 * emulated. A 31 bit program peeking into the struct user of
534 * a 64 bit program is a no-no.
535 */
536
537/*
538 * Same as peek_user_per but for a 31 bit program.
539 */
540static inline __u32 __peek_user_per_compat(struct task_struct *child,
541 addr_t addr)
542{
543 struct compat_per_struct_kernel *dummy32 = NULL;
544
545 if (addr == (addr_t) &dummy32->cr9)
546 /* Control bits of the active per set. */
547 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
548 PER_EVENT_IFETCH : child->thread.per_user.control;
549 else if (addr == (addr_t) &dummy32->cr10)
550 /* Start address of the active per set. */
551 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
552 0 : child->thread.per_user.start;
553 else if (addr == (addr_t) &dummy32->cr11)
554 /* End address of the active per set. */
555 return test_thread_flag(TIF_SINGLE_STEP) ?
556 PSW32_ADDR_INSN : child->thread.per_user.end;
557 else if (addr == (addr_t) &dummy32->bits)
558 /* Single-step bit. */
559 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
560 0x80000000 : 0;
561 else if (addr == (addr_t) &dummy32->starting_addr)
562 /* Start address of the user specified per set. */
563 return (__u32) child->thread.per_user.start;
564 else if (addr == (addr_t) &dummy32->ending_addr)
565 /* End address of the user specified per set. */
566 return (__u32) child->thread.per_user.end;
567 else if (addr == (addr_t) &dummy32->perc_atmid)
568 /* PER code, ATMID and AI of the last PER trap */
569 return (__u32) child->thread.per_event.cause << 16;
570 else if (addr == (addr_t) &dummy32->address)
571 /* Address of the last PER trap */
572 return (__u32) child->thread.per_event.address;
573 else if (addr == (addr_t) &dummy32->access_id)
574 /* Access id of the last PER trap */
575 return (__u32) child->thread.per_event.paid << 24;
576 return 0;
577}
578
579/*
580 * Same as peek_user but for a 31 bit program.
581 */
582static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
583{
584 struct compat_user *dummy32 = NULL;
585 addr_t offset;
586 __u32 tmp;
587
588 if (addr < (addr_t) &dummy32->regs.acrs) {
589 struct pt_regs *regs = task_pt_regs(child);
590 /*
591 * psw and gprs are stored on the stack
592 */
593 if (addr == (addr_t) &dummy32->regs.psw.mask) {
594 /* Fake a 31 bit psw mask. */
595 tmp = (__u32)(regs->psw.mask >> 32);
596 tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
597 tmp |= PSW32_USER_BITS;
598 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
599 /* Fake a 31 bit psw address. */
600 tmp = (__u32) regs->psw.addr |
601 (__u32)(regs->psw.mask & PSW_MASK_BA);
602 } else {
603 /* gpr 0-15 */
604 tmp = *(__u32 *)((addr_t) ®s->psw + addr*2 + 4);
605 }
606 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
607 /*
608 * access registers are stored in the thread structure
609 */
610 offset = addr - (addr_t) &dummy32->regs.acrs;
611 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
612
613 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
614 /*
615 * orig_gpr2 is stored on the kernel stack
616 */
617 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
618
619 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
620 /*
621 * prevent reads of padding hole between
622 * orig_gpr2 and fp_regs on s390.
623 */
624 tmp = 0;
625
626 } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
627 /*
628 * floating point control reg. is in the thread structure
629 */
630 tmp = child->thread.fpu.fpc;
631
632 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
633 /*
634 * floating point regs. are either in child->thread.fpu
635 * or the child->thread.fpu.vxrs array
636 */
637 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
638 if (MACHINE_HAS_VX)
639 tmp = *(__u32 *)
640 ((addr_t) child->thread.fpu.vxrs + 2*offset);
641 else
642 tmp = *(__u32 *)
643 ((addr_t) child->thread.fpu.fprs + offset);
644
645 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
646 /*
647 * Handle access to the per_info structure.
648 */
649 addr -= (addr_t) &dummy32->regs.per_info;
650 tmp = __peek_user_per_compat(child, addr);
651
652 } else
653 tmp = 0;
654
655 return tmp;
656}
657
658static int peek_user_compat(struct task_struct *child,
659 addr_t addr, addr_t data)
660{
661 __u32 tmp;
662
663 if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
664 return -EIO;
665
666 tmp = __peek_user_compat(child, addr);
667 return put_user(tmp, (__u32 __user *) data);
668}
669
670/*
671 * Same as poke_user_per but for a 31 bit program.
672 */
673static inline void __poke_user_per_compat(struct task_struct *child,
674 addr_t addr, __u32 data)
675{
676 struct compat_per_struct_kernel *dummy32 = NULL;
677
678 if (addr == (addr_t) &dummy32->cr9)
679 /* PER event mask of the user specified per set. */
680 child->thread.per_user.control =
681 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
682 else if (addr == (addr_t) &dummy32->starting_addr)
683 /* Starting address of the user specified per set. */
684 child->thread.per_user.start = data;
685 else if (addr == (addr_t) &dummy32->ending_addr)
686 /* Ending address of the user specified per set. */
687 child->thread.per_user.end = data;
688}
689
690/*
691 * Same as poke_user but for a 31 bit program.
692 */
693static int __poke_user_compat(struct task_struct *child,
694 addr_t addr, addr_t data)
695{
696 struct compat_user *dummy32 = NULL;
697 __u32 tmp = (__u32) data;
698 addr_t offset;
699
700 if (addr < (addr_t) &dummy32->regs.acrs) {
701 struct pt_regs *regs = task_pt_regs(child);
702 /*
703 * psw, gprs, acrs and orig_gpr2 are stored on the stack
704 */
705 if (addr == (addr_t) &dummy32->regs.psw.mask) {
706 __u32 mask = PSW32_MASK_USER;
707
708 mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
709 /* Build a 64 bit psw mask from 31 bit mask. */
710 if ((tmp ^ PSW32_USER_BITS) & ~mask)
711 /* Invalid psw mask. */
712 return -EINVAL;
713 if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
714 /* Invalid address-space-control bits */
715 return -EINVAL;
716 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
717 (regs->psw.mask & PSW_MASK_BA) |
718 (__u64)(tmp & mask) << 32;
719 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
720 /* Build a 64 bit psw address from 31 bit address. */
721 regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
722 /* Transfer 31 bit amode bit to psw mask. */
723 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
724 (__u64)(tmp & PSW32_ADDR_AMODE);
725 } else {
726 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
727 addr == offsetof(struct compat_user, regs.gprs[2])) {
728 struct pt_regs *regs = task_pt_regs(child);
729
730 regs->int_code = 0x20000 | (data & 0xffff);
731 }
732 /* gpr 0-15 */
733 *(__u32*)((addr_t) ®s->psw + addr*2 + 4) = tmp;
734 }
735 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
736 /*
737 * access registers are stored in the thread structure
738 */
739 offset = addr - (addr_t) &dummy32->regs.acrs;
740 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
741
742 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
743 /*
744 * orig_gpr2 is stored on the kernel stack
745 */
746 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
747
748 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
749 /*
750 * prevent writess of padding hole between
751 * orig_gpr2 and fp_regs on s390.
752 */
753 return 0;
754
755 } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
756 /*
757 * floating point control reg. is in the thread structure
758 */
759 if (test_fp_ctl(tmp))
760 return -EINVAL;
761 child->thread.fpu.fpc = data;
762
763 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
764 /*
765 * floating point regs. are either in child->thread.fpu
766 * or the child->thread.fpu.vxrs array
767 */
768 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
769 if (MACHINE_HAS_VX)
770 *(__u32 *)((addr_t)
771 child->thread.fpu.vxrs + 2*offset) = tmp;
772 else
773 *(__u32 *)((addr_t)
774 child->thread.fpu.fprs + offset) = tmp;
775
776 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
777 /*
778 * Handle access to the per_info structure.
779 */
780 addr -= (addr_t) &dummy32->regs.per_info;
781 __poke_user_per_compat(child, addr, data);
782 }
783
784 return 0;
785}
786
787static int poke_user_compat(struct task_struct *child,
788 addr_t addr, addr_t data)
789{
790 if (!is_compat_task() || (addr & 3) ||
791 addr > sizeof(struct compat_user) - 3)
792 return -EIO;
793
794 return __poke_user_compat(child, addr, data);
795}
796
797long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
798 compat_ulong_t caddr, compat_ulong_t cdata)
799{
800 unsigned long addr = caddr;
801 unsigned long data = cdata;
802 compat_ptrace_area parea;
803 int copied, ret;
804
805 switch (request) {
806 case PTRACE_PEEKUSR:
807 /* read the word at location addr in the USER area. */
808 return peek_user_compat(child, addr, data);
809
810 case PTRACE_POKEUSR:
811 /* write the word at location addr in the USER area */
812 return poke_user_compat(child, addr, data);
813
814 case PTRACE_PEEKUSR_AREA:
815 case PTRACE_POKEUSR_AREA:
816 if (copy_from_user(&parea, (void __force __user *) addr,
817 sizeof(parea)))
818 return -EFAULT;
819 addr = parea.kernel_addr;
820 data = parea.process_addr;
821 copied = 0;
822 while (copied < parea.len) {
823 if (request == PTRACE_PEEKUSR_AREA)
824 ret = peek_user_compat(child, addr, data);
825 else {
826 __u32 utmp;
827 if (get_user(utmp,
828 (__u32 __force __user *) data))
829 return -EFAULT;
830 ret = poke_user_compat(child, addr, utmp);
831 }
832 if (ret)
833 return ret;
834 addr += sizeof(unsigned int);
835 data += sizeof(unsigned int);
836 copied += sizeof(unsigned int);
837 }
838 return 0;
839 case PTRACE_GET_LAST_BREAK:
840 put_user(child->thread.last_break,
841 (unsigned int __user *) data);
842 return 0;
843 }
844 return compat_ptrace_request(child, request, addr, data);
845}
846#endif
847
848/*
849 * user_regset definitions.
850 */
851
852static int s390_regs_get(struct task_struct *target,
853 const struct user_regset *regset,
854 struct membuf to)
855{
856 unsigned pos;
857 if (target == current)
858 save_access_regs(target->thread.acrs);
859
860 for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
861 membuf_store(&to, __peek_user(target, pos));
862 return 0;
863}
864
865static int s390_regs_set(struct task_struct *target,
866 const struct user_regset *regset,
867 unsigned int pos, unsigned int count,
868 const void *kbuf, const void __user *ubuf)
869{
870 int rc = 0;
871
872 if (target == current)
873 save_access_regs(target->thread.acrs);
874
875 if (kbuf) {
876 const unsigned long *k = kbuf;
877 while (count > 0 && !rc) {
878 rc = __poke_user(target, pos, *k++);
879 count -= sizeof(*k);
880 pos += sizeof(*k);
881 }
882 } else {
883 const unsigned long __user *u = ubuf;
884 while (count > 0 && !rc) {
885 unsigned long word;
886 rc = __get_user(word, u++);
887 if (rc)
888 break;
889 rc = __poke_user(target, pos, word);
890 count -= sizeof(*u);
891 pos += sizeof(*u);
892 }
893 }
894
895 if (rc == 0 && target == current)
896 restore_access_regs(target->thread.acrs);
897
898 return rc;
899}
900
901static int s390_fpregs_get(struct task_struct *target,
902 const struct user_regset *regset,
903 struct membuf to)
904{
905 _s390_fp_regs fp_regs;
906
907 if (target == current)
908 save_fpu_regs();
909
910 fp_regs.fpc = target->thread.fpu.fpc;
911 fpregs_store(&fp_regs, &target->thread.fpu);
912
913 return membuf_write(&to, &fp_regs, sizeof(fp_regs));
914}
915
916static int s390_fpregs_set(struct task_struct *target,
917 const struct user_regset *regset, unsigned int pos,
918 unsigned int count, const void *kbuf,
919 const void __user *ubuf)
920{
921 int rc = 0;
922 freg_t fprs[__NUM_FPRS];
923
924 if (target == current)
925 save_fpu_regs();
926
927 if (MACHINE_HAS_VX)
928 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
929 else
930 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
931
932 /* If setting FPC, must validate it first. */
933 if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
934 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
935 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
936 0, offsetof(s390_fp_regs, fprs));
937 if (rc)
938 return rc;
939 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
940 return -EINVAL;
941 target->thread.fpu.fpc = ufpc[0];
942 }
943
944 if (rc == 0 && count > 0)
945 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
946 fprs, offsetof(s390_fp_regs, fprs), -1);
947 if (rc)
948 return rc;
949
950 if (MACHINE_HAS_VX)
951 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
952 else
953 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
954
955 return rc;
956}
957
958static int s390_last_break_get(struct task_struct *target,
959 const struct user_regset *regset,
960 struct membuf to)
961{
962 return membuf_store(&to, target->thread.last_break);
963}
964
965static int s390_last_break_set(struct task_struct *target,
966 const struct user_regset *regset,
967 unsigned int pos, unsigned int count,
968 const void *kbuf, const void __user *ubuf)
969{
970 return 0;
971}
972
973static int s390_tdb_get(struct task_struct *target,
974 const struct user_regset *regset,
975 struct membuf to)
976{
977 struct pt_regs *regs = task_pt_regs(target);
978 size_t size;
979
980 if (!(regs->int_code & 0x200))
981 return -ENODATA;
982 size = sizeof(target->thread.trap_tdb.data);
983 return membuf_write(&to, target->thread.trap_tdb.data, size);
984}
985
986static int s390_tdb_set(struct task_struct *target,
987 const struct user_regset *regset,
988 unsigned int pos, unsigned int count,
989 const void *kbuf, const void __user *ubuf)
990{
991 return 0;
992}
993
994static int s390_vxrs_low_get(struct task_struct *target,
995 const struct user_regset *regset,
996 struct membuf to)
997{
998 __u64 vxrs[__NUM_VXRS_LOW];
999 int i;
1000
1001 if (!MACHINE_HAS_VX)
1002 return -ENODEV;
1003 if (target == current)
1004 save_fpu_regs();
1005 for (i = 0; i < __NUM_VXRS_LOW; i++)
1006 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1007 return membuf_write(&to, vxrs, sizeof(vxrs));
1008}
1009
1010static int s390_vxrs_low_set(struct task_struct *target,
1011 const struct user_regset *regset,
1012 unsigned int pos, unsigned int count,
1013 const void *kbuf, const void __user *ubuf)
1014{
1015 __u64 vxrs[__NUM_VXRS_LOW];
1016 int i, rc;
1017
1018 if (!MACHINE_HAS_VX)
1019 return -ENODEV;
1020 if (target == current)
1021 save_fpu_regs();
1022
1023 for (i = 0; i < __NUM_VXRS_LOW; i++)
1024 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1025
1026 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1027 if (rc == 0)
1028 for (i = 0; i < __NUM_VXRS_LOW; i++)
1029 *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1030
1031 return rc;
1032}
1033
1034static int s390_vxrs_high_get(struct task_struct *target,
1035 const struct user_regset *regset,
1036 struct membuf to)
1037{
1038 if (!MACHINE_HAS_VX)
1039 return -ENODEV;
1040 if (target == current)
1041 save_fpu_regs();
1042 return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1043 __NUM_VXRS_HIGH * sizeof(__vector128));
1044}
1045
1046static int s390_vxrs_high_set(struct task_struct *target,
1047 const struct user_regset *regset,
1048 unsigned int pos, unsigned int count,
1049 const void *kbuf, const void __user *ubuf)
1050{
1051 int rc;
1052
1053 if (!MACHINE_HAS_VX)
1054 return -ENODEV;
1055 if (target == current)
1056 save_fpu_regs();
1057
1058 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1059 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1060 return rc;
1061}
1062
1063static int s390_system_call_get(struct task_struct *target,
1064 const struct user_regset *regset,
1065 struct membuf to)
1066{
1067 return membuf_store(&to, target->thread.system_call);
1068}
1069
1070static int s390_system_call_set(struct task_struct *target,
1071 const struct user_regset *regset,
1072 unsigned int pos, unsigned int count,
1073 const void *kbuf, const void __user *ubuf)
1074{
1075 unsigned int *data = &target->thread.system_call;
1076 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1077 data, 0, sizeof(unsigned int));
1078}
1079
1080static int s390_gs_cb_get(struct task_struct *target,
1081 const struct user_regset *regset,
1082 struct membuf to)
1083{
1084 struct gs_cb *data = target->thread.gs_cb;
1085
1086 if (!MACHINE_HAS_GS)
1087 return -ENODEV;
1088 if (!data)
1089 return -ENODATA;
1090 if (target == current)
1091 save_gs_cb(data);
1092 return membuf_write(&to, data, sizeof(struct gs_cb));
1093}
1094
1095static int s390_gs_cb_set(struct task_struct *target,
1096 const struct user_regset *regset,
1097 unsigned int pos, unsigned int count,
1098 const void *kbuf, const void __user *ubuf)
1099{
1100 struct gs_cb gs_cb = { }, *data = NULL;
1101 int rc;
1102
1103 if (!MACHINE_HAS_GS)
1104 return -ENODEV;
1105 if (!target->thread.gs_cb) {
1106 data = kzalloc(sizeof(*data), GFP_KERNEL);
1107 if (!data)
1108 return -ENOMEM;
1109 }
1110 if (!target->thread.gs_cb)
1111 gs_cb.gsd = 25;
1112 else if (target == current)
1113 save_gs_cb(&gs_cb);
1114 else
1115 gs_cb = *target->thread.gs_cb;
1116 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1117 &gs_cb, 0, sizeof(gs_cb));
1118 if (rc) {
1119 kfree(data);
1120 return -EFAULT;
1121 }
1122 preempt_disable();
1123 if (!target->thread.gs_cb)
1124 target->thread.gs_cb = data;
1125 *target->thread.gs_cb = gs_cb;
1126 if (target == current) {
1127 __ctl_set_bit(2, 4);
1128 restore_gs_cb(target->thread.gs_cb);
1129 }
1130 preempt_enable();
1131 return rc;
1132}
1133
1134static int s390_gs_bc_get(struct task_struct *target,
1135 const struct user_regset *regset,
1136 struct membuf to)
1137{
1138 struct gs_cb *data = target->thread.gs_bc_cb;
1139
1140 if (!MACHINE_HAS_GS)
1141 return -ENODEV;
1142 if (!data)
1143 return -ENODATA;
1144 return membuf_write(&to, data, sizeof(struct gs_cb));
1145}
1146
1147static int s390_gs_bc_set(struct task_struct *target,
1148 const struct user_regset *regset,
1149 unsigned int pos, unsigned int count,
1150 const void *kbuf, const void __user *ubuf)
1151{
1152 struct gs_cb *data = target->thread.gs_bc_cb;
1153
1154 if (!MACHINE_HAS_GS)
1155 return -ENODEV;
1156 if (!data) {
1157 data = kzalloc(sizeof(*data), GFP_KERNEL);
1158 if (!data)
1159 return -ENOMEM;
1160 target->thread.gs_bc_cb = data;
1161 }
1162 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1163 data, 0, sizeof(struct gs_cb));
1164}
1165
1166static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1167{
1168 return (cb->rca & 0x1f) == 0 &&
1169 (cb->roa & 0xfff) == 0 &&
1170 (cb->rla & 0xfff) == 0xfff &&
1171 cb->s == 1 &&
1172 cb->k == 1 &&
1173 cb->h == 0 &&
1174 cb->reserved1 == 0 &&
1175 cb->ps == 1 &&
1176 cb->qs == 0 &&
1177 cb->pc == 1 &&
1178 cb->qc == 0 &&
1179 cb->reserved2 == 0 &&
1180 cb->reserved3 == 0 &&
1181 cb->reserved4 == 0 &&
1182 cb->reserved5 == 0 &&
1183 cb->reserved6 == 0 &&
1184 cb->reserved7 == 0 &&
1185 cb->reserved8 == 0 &&
1186 cb->rla >= cb->roa &&
1187 cb->rca >= cb->roa &&
1188 cb->rca <= cb->rla+1 &&
1189 cb->m < 3;
1190}
1191
1192static int s390_runtime_instr_get(struct task_struct *target,
1193 const struct user_regset *regset,
1194 struct membuf to)
1195{
1196 struct runtime_instr_cb *data = target->thread.ri_cb;
1197
1198 if (!test_facility(64))
1199 return -ENODEV;
1200 if (!data)
1201 return -ENODATA;
1202
1203 return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1204}
1205
1206static int s390_runtime_instr_set(struct task_struct *target,
1207 const struct user_regset *regset,
1208 unsigned int pos, unsigned int count,
1209 const void *kbuf, const void __user *ubuf)
1210{
1211 struct runtime_instr_cb ri_cb = { }, *data = NULL;
1212 int rc;
1213
1214 if (!test_facility(64))
1215 return -ENODEV;
1216
1217 if (!target->thread.ri_cb) {
1218 data = kzalloc(sizeof(*data), GFP_KERNEL);
1219 if (!data)
1220 return -ENOMEM;
1221 }
1222
1223 if (target->thread.ri_cb) {
1224 if (target == current)
1225 store_runtime_instr_cb(&ri_cb);
1226 else
1227 ri_cb = *target->thread.ri_cb;
1228 }
1229
1230 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1231 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1232 if (rc) {
1233 kfree(data);
1234 return -EFAULT;
1235 }
1236
1237 if (!is_ri_cb_valid(&ri_cb)) {
1238 kfree(data);
1239 return -EINVAL;
1240 }
1241 /*
1242 * Override access key in any case, since user space should
1243 * not be able to set it, nor should it care about it.
1244 */
1245 ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1246 preempt_disable();
1247 if (!target->thread.ri_cb)
1248 target->thread.ri_cb = data;
1249 *target->thread.ri_cb = ri_cb;
1250 if (target == current)
1251 load_runtime_instr_cb(target->thread.ri_cb);
1252 preempt_enable();
1253
1254 return 0;
1255}
1256
1257static const struct user_regset s390_regsets[] = {
1258 {
1259 .core_note_type = NT_PRSTATUS,
1260 .n = sizeof(s390_regs) / sizeof(long),
1261 .size = sizeof(long),
1262 .align = sizeof(long),
1263 .regset_get = s390_regs_get,
1264 .set = s390_regs_set,
1265 },
1266 {
1267 .core_note_type = NT_PRFPREG,
1268 .n = sizeof(s390_fp_regs) / sizeof(long),
1269 .size = sizeof(long),
1270 .align = sizeof(long),
1271 .regset_get = s390_fpregs_get,
1272 .set = s390_fpregs_set,
1273 },
1274 {
1275 .core_note_type = NT_S390_SYSTEM_CALL,
1276 .n = 1,
1277 .size = sizeof(unsigned int),
1278 .align = sizeof(unsigned int),
1279 .regset_get = s390_system_call_get,
1280 .set = s390_system_call_set,
1281 },
1282 {
1283 .core_note_type = NT_S390_LAST_BREAK,
1284 .n = 1,
1285 .size = sizeof(long),
1286 .align = sizeof(long),
1287 .regset_get = s390_last_break_get,
1288 .set = s390_last_break_set,
1289 },
1290 {
1291 .core_note_type = NT_S390_TDB,
1292 .n = 1,
1293 .size = 256,
1294 .align = 1,
1295 .regset_get = s390_tdb_get,
1296 .set = s390_tdb_set,
1297 },
1298 {
1299 .core_note_type = NT_S390_VXRS_LOW,
1300 .n = __NUM_VXRS_LOW,
1301 .size = sizeof(__u64),
1302 .align = sizeof(__u64),
1303 .regset_get = s390_vxrs_low_get,
1304 .set = s390_vxrs_low_set,
1305 },
1306 {
1307 .core_note_type = NT_S390_VXRS_HIGH,
1308 .n = __NUM_VXRS_HIGH,
1309 .size = sizeof(__vector128),
1310 .align = sizeof(__vector128),
1311 .regset_get = s390_vxrs_high_get,
1312 .set = s390_vxrs_high_set,
1313 },
1314 {
1315 .core_note_type = NT_S390_GS_CB,
1316 .n = sizeof(struct gs_cb) / sizeof(__u64),
1317 .size = sizeof(__u64),
1318 .align = sizeof(__u64),
1319 .regset_get = s390_gs_cb_get,
1320 .set = s390_gs_cb_set,
1321 },
1322 {
1323 .core_note_type = NT_S390_GS_BC,
1324 .n = sizeof(struct gs_cb) / sizeof(__u64),
1325 .size = sizeof(__u64),
1326 .align = sizeof(__u64),
1327 .regset_get = s390_gs_bc_get,
1328 .set = s390_gs_bc_set,
1329 },
1330 {
1331 .core_note_type = NT_S390_RI_CB,
1332 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1333 .size = sizeof(__u64),
1334 .align = sizeof(__u64),
1335 .regset_get = s390_runtime_instr_get,
1336 .set = s390_runtime_instr_set,
1337 },
1338};
1339
1340static const struct user_regset_view user_s390_view = {
1341 .name = "s390x",
1342 .e_machine = EM_S390,
1343 .regsets = s390_regsets,
1344 .n = ARRAY_SIZE(s390_regsets)
1345};
1346
1347#ifdef CONFIG_COMPAT
1348static int s390_compat_regs_get(struct task_struct *target,
1349 const struct user_regset *regset,
1350 struct membuf to)
1351{
1352 unsigned n;
1353
1354 if (target == current)
1355 save_access_regs(target->thread.acrs);
1356
1357 for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1358 membuf_store(&to, __peek_user_compat(target, n));
1359 return 0;
1360}
1361
1362static int s390_compat_regs_set(struct task_struct *target,
1363 const struct user_regset *regset,
1364 unsigned int pos, unsigned int count,
1365 const void *kbuf, const void __user *ubuf)
1366{
1367 int rc = 0;
1368
1369 if (target == current)
1370 save_access_regs(target->thread.acrs);
1371
1372 if (kbuf) {
1373 const compat_ulong_t *k = kbuf;
1374 while (count > 0 && !rc) {
1375 rc = __poke_user_compat(target, pos, *k++);
1376 count -= sizeof(*k);
1377 pos += sizeof(*k);
1378 }
1379 } else {
1380 const compat_ulong_t __user *u = ubuf;
1381 while (count > 0 && !rc) {
1382 compat_ulong_t word;
1383 rc = __get_user(word, u++);
1384 if (rc)
1385 break;
1386 rc = __poke_user_compat(target, pos, word);
1387 count -= sizeof(*u);
1388 pos += sizeof(*u);
1389 }
1390 }
1391
1392 if (rc == 0 && target == current)
1393 restore_access_regs(target->thread.acrs);
1394
1395 return rc;
1396}
1397
1398static int s390_compat_regs_high_get(struct task_struct *target,
1399 const struct user_regset *regset,
1400 struct membuf to)
1401{
1402 compat_ulong_t *gprs_high;
1403 int i;
1404
1405 gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1406 for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1407 membuf_store(&to, *gprs_high);
1408 return 0;
1409}
1410
1411static int s390_compat_regs_high_set(struct task_struct *target,
1412 const struct user_regset *regset,
1413 unsigned int pos, unsigned int count,
1414 const void *kbuf, const void __user *ubuf)
1415{
1416 compat_ulong_t *gprs_high;
1417 int rc = 0;
1418
1419 gprs_high = (compat_ulong_t *)
1420 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1421 if (kbuf) {
1422 const compat_ulong_t *k = kbuf;
1423 while (count > 0) {
1424 *gprs_high = *k++;
1425 *gprs_high += 2;
1426 count -= sizeof(*k);
1427 }
1428 } else {
1429 const compat_ulong_t __user *u = ubuf;
1430 while (count > 0 && !rc) {
1431 unsigned long word;
1432 rc = __get_user(word, u++);
1433 if (rc)
1434 break;
1435 *gprs_high = word;
1436 *gprs_high += 2;
1437 count -= sizeof(*u);
1438 }
1439 }
1440
1441 return rc;
1442}
1443
1444static int s390_compat_last_break_get(struct task_struct *target,
1445 const struct user_regset *regset,
1446 struct membuf to)
1447{
1448 compat_ulong_t last_break = target->thread.last_break;
1449
1450 return membuf_store(&to, (unsigned long)last_break);
1451}
1452
1453static int s390_compat_last_break_set(struct task_struct *target,
1454 const struct user_regset *regset,
1455 unsigned int pos, unsigned int count,
1456 const void *kbuf, const void __user *ubuf)
1457{
1458 return 0;
1459}
1460
1461static const struct user_regset s390_compat_regsets[] = {
1462 {
1463 .core_note_type = NT_PRSTATUS,
1464 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1465 .size = sizeof(compat_long_t),
1466 .align = sizeof(compat_long_t),
1467 .regset_get = s390_compat_regs_get,
1468 .set = s390_compat_regs_set,
1469 },
1470 {
1471 .core_note_type = NT_PRFPREG,
1472 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1473 .size = sizeof(compat_long_t),
1474 .align = sizeof(compat_long_t),
1475 .regset_get = s390_fpregs_get,
1476 .set = s390_fpregs_set,
1477 },
1478 {
1479 .core_note_type = NT_S390_SYSTEM_CALL,
1480 .n = 1,
1481 .size = sizeof(compat_uint_t),
1482 .align = sizeof(compat_uint_t),
1483 .regset_get = s390_system_call_get,
1484 .set = s390_system_call_set,
1485 },
1486 {
1487 .core_note_type = NT_S390_LAST_BREAK,
1488 .n = 1,
1489 .size = sizeof(long),
1490 .align = sizeof(long),
1491 .regset_get = s390_compat_last_break_get,
1492 .set = s390_compat_last_break_set,
1493 },
1494 {
1495 .core_note_type = NT_S390_TDB,
1496 .n = 1,
1497 .size = 256,
1498 .align = 1,
1499 .regset_get = s390_tdb_get,
1500 .set = s390_tdb_set,
1501 },
1502 {
1503 .core_note_type = NT_S390_VXRS_LOW,
1504 .n = __NUM_VXRS_LOW,
1505 .size = sizeof(__u64),
1506 .align = sizeof(__u64),
1507 .regset_get = s390_vxrs_low_get,
1508 .set = s390_vxrs_low_set,
1509 },
1510 {
1511 .core_note_type = NT_S390_VXRS_HIGH,
1512 .n = __NUM_VXRS_HIGH,
1513 .size = sizeof(__vector128),
1514 .align = sizeof(__vector128),
1515 .regset_get = s390_vxrs_high_get,
1516 .set = s390_vxrs_high_set,
1517 },
1518 {
1519 .core_note_type = NT_S390_HIGH_GPRS,
1520 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1521 .size = sizeof(compat_long_t),
1522 .align = sizeof(compat_long_t),
1523 .regset_get = s390_compat_regs_high_get,
1524 .set = s390_compat_regs_high_set,
1525 },
1526 {
1527 .core_note_type = NT_S390_GS_CB,
1528 .n = sizeof(struct gs_cb) / sizeof(__u64),
1529 .size = sizeof(__u64),
1530 .align = sizeof(__u64),
1531 .regset_get = s390_gs_cb_get,
1532 .set = s390_gs_cb_set,
1533 },
1534 {
1535 .core_note_type = NT_S390_GS_BC,
1536 .n = sizeof(struct gs_cb) / sizeof(__u64),
1537 .size = sizeof(__u64),
1538 .align = sizeof(__u64),
1539 .regset_get = s390_gs_bc_get,
1540 .set = s390_gs_bc_set,
1541 },
1542 {
1543 .core_note_type = NT_S390_RI_CB,
1544 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1545 .size = sizeof(__u64),
1546 .align = sizeof(__u64),
1547 .regset_get = s390_runtime_instr_get,
1548 .set = s390_runtime_instr_set,
1549 },
1550};
1551
1552static const struct user_regset_view user_s390_compat_view = {
1553 .name = "s390",
1554 .e_machine = EM_S390,
1555 .regsets = s390_compat_regsets,
1556 .n = ARRAY_SIZE(s390_compat_regsets)
1557};
1558#endif
1559
1560const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1561{
1562#ifdef CONFIG_COMPAT
1563 if (test_tsk_thread_flag(task, TIF_31BIT))
1564 return &user_s390_compat_view;
1565#endif
1566 return &user_s390_view;
1567}
1568
1569static const char *gpr_names[NUM_GPRS] = {
1570 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
1571 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1572};
1573
1574unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1575{
1576 if (offset >= NUM_GPRS)
1577 return 0;
1578 return regs->gprs[offset];
1579}
1580
1581int regs_query_register_offset(const char *name)
1582{
1583 unsigned long offset;
1584
1585 if (!name || *name != 'r')
1586 return -EINVAL;
1587 if (kstrtoul(name + 1, 10, &offset))
1588 return -EINVAL;
1589 if (offset >= NUM_GPRS)
1590 return -EINVAL;
1591 return offset;
1592}
1593
1594const char *regs_query_register_name(unsigned int offset)
1595{
1596 if (offset >= NUM_GPRS)
1597 return NULL;
1598 return gpr_names[offset];
1599}
1600
1601static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1602{
1603 unsigned long ksp = kernel_stack_pointer(regs);
1604
1605 return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1606}
1607
1608/**
1609 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1610 * @regs:pt_regs which contains kernel stack pointer.
1611 * @n:stack entry number.
1612 *
1613 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1614 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1615 * this returns 0.
1616 */
1617unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1618{
1619 unsigned long addr;
1620
1621 addr = kernel_stack_pointer(regs) + n * sizeof(long);
1622 if (!regs_within_kernel_stack(regs, addr))
1623 return 0;
1624 return *(unsigned long *)addr;
1625}