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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/segment.h>
28#include <asm/page.h>
29#include <asm/pgtable.h>
30#include <asm/pgalloc.h>
31#include <linux/uaccess.h>
32#include <asm/unistd.h>
33#include <asm/switch_to.h>
34#include <asm/runtime_instr.h>
35#include <asm/facility.h>
36
37#include "entry.h"
38
39#ifdef CONFIG_COMPAT
40#include "compat_ptrace.h"
41#endif
42
43#define CREATE_TRACE_POINTS
44#include <trace/events/syscalls.h>
45
46void update_cr_regs(struct task_struct *task)
47{
48 struct pt_regs *regs = task_pt_regs(task);
49 struct thread_struct *thread = &task->thread;
50 struct per_regs old, new;
51 union ctlreg0 cr0_old, cr0_new;
52 union ctlreg2 cr2_old, cr2_new;
53 int cr0_changed, cr2_changed;
54
55 __ctl_store(cr0_old.val, 0, 0);
56 __ctl_store(cr2_old.val, 2, 2);
57 cr0_new = cr0_old;
58 cr2_new = cr2_old;
59 /* Take care of the enable/disable of transactional execution. */
60 if (MACHINE_HAS_TE) {
61 /* Set or clear transaction execution TXC bit 8. */
62 cr0_new.tcx = 1;
63 if (task->thread.per_flags & PER_FLAG_NO_TE)
64 cr0_new.tcx = 0;
65 /* Set or clear transaction execution TDC bits 62 and 63. */
66 cr2_new.tdc = 0;
67 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
68 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
69 cr2_new.tdc = 1;
70 else
71 cr2_new.tdc = 2;
72 }
73 }
74 /* Take care of enable/disable of guarded storage. */
75 if (MACHINE_HAS_GS) {
76 cr2_new.gse = 0;
77 if (task->thread.gs_cb)
78 cr2_new.gse = 1;
79 }
80 /* Load control register 0/2 iff changed */
81 cr0_changed = cr0_new.val != cr0_old.val;
82 cr2_changed = cr2_new.val != cr2_old.val;
83 if (cr0_changed)
84 __ctl_load(cr0_new.val, 0, 0);
85 if (cr2_changed)
86 __ctl_load(cr2_new.val, 2, 2);
87 /* Copy user specified PER registers */
88 new.control = thread->per_user.control;
89 new.start = thread->per_user.start;
90 new.end = thread->per_user.end;
91
92 /* merge TIF_SINGLE_STEP into user specified PER registers. */
93 if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
94 test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
95 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
96 new.control |= PER_EVENT_BRANCH;
97 else
98 new.control |= PER_EVENT_IFETCH;
99 new.control |= PER_CONTROL_SUSPENSION;
100 new.control |= PER_EVENT_TRANSACTION_END;
101 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
102 new.control |= PER_EVENT_IFETCH;
103 new.start = 0;
104 new.end = -1UL;
105 }
106
107 /* Take care of the PER enablement bit in the PSW. */
108 if (!(new.control & PER_EVENT_MASK)) {
109 regs->psw.mask &= ~PSW_MASK_PER;
110 return;
111 }
112 regs->psw.mask |= PSW_MASK_PER;
113 __ctl_store(old, 9, 11);
114 if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
115 __ctl_load(new, 9, 11);
116}
117
118void user_enable_single_step(struct task_struct *task)
119{
120 clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
121 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
122}
123
124void user_disable_single_step(struct task_struct *task)
125{
126 clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
127 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
128}
129
130void user_enable_block_step(struct task_struct *task)
131{
132 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
133 set_tsk_thread_flag(task, TIF_BLOCK_STEP);
134}
135
136/*
137 * Called by kernel/ptrace.c when detaching..
138 *
139 * Clear all debugging related fields.
140 */
141void ptrace_disable(struct task_struct *task)
142{
143 memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
144 memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
145 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
146 clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
147 task->thread.per_flags = 0;
148}
149
150#define __ADDR_MASK 7
151
152static inline unsigned long __peek_user_per(struct task_struct *child,
153 addr_t addr)
154{
155 struct per_struct_kernel *dummy = NULL;
156
157 if (addr == (addr_t) &dummy->cr9)
158 /* Control bits of the active per set. */
159 return test_thread_flag(TIF_SINGLE_STEP) ?
160 PER_EVENT_IFETCH : child->thread.per_user.control;
161 else if (addr == (addr_t) &dummy->cr10)
162 /* Start address of the active per set. */
163 return test_thread_flag(TIF_SINGLE_STEP) ?
164 0 : child->thread.per_user.start;
165 else if (addr == (addr_t) &dummy->cr11)
166 /* End address of the active per set. */
167 return test_thread_flag(TIF_SINGLE_STEP) ?
168 -1UL : child->thread.per_user.end;
169 else if (addr == (addr_t) &dummy->bits)
170 /* Single-step bit. */
171 return test_thread_flag(TIF_SINGLE_STEP) ?
172 (1UL << (BITS_PER_LONG - 1)) : 0;
173 else if (addr == (addr_t) &dummy->starting_addr)
174 /* Start address of the user specified per set. */
175 return child->thread.per_user.start;
176 else if (addr == (addr_t) &dummy->ending_addr)
177 /* End address of the user specified per set. */
178 return child->thread.per_user.end;
179 else if (addr == (addr_t) &dummy->perc_atmid)
180 /* PER code, ATMID and AI of the last PER trap */
181 return (unsigned long)
182 child->thread.per_event.cause << (BITS_PER_LONG - 16);
183 else if (addr == (addr_t) &dummy->address)
184 /* Address of the last PER trap */
185 return child->thread.per_event.address;
186 else if (addr == (addr_t) &dummy->access_id)
187 /* Access id of the last PER trap */
188 return (unsigned long)
189 child->thread.per_event.paid << (BITS_PER_LONG - 8);
190 return 0;
191}
192
193/*
194 * Read the word at offset addr from the user area of a process. The
195 * trouble here is that the information is littered over different
196 * locations. The process registers are found on the kernel stack,
197 * the floating point stuff and the trace settings are stored in
198 * the task structure. In addition the different structures in
199 * struct user contain pad bytes that should be read as zeroes.
200 * Lovely...
201 */
202static unsigned long __peek_user(struct task_struct *child, addr_t addr)
203{
204 struct user *dummy = NULL;
205 addr_t offset, tmp;
206
207 if (addr < (addr_t) &dummy->regs.acrs) {
208 /*
209 * psw and gprs are stored on the stack
210 */
211 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
212 if (addr == (addr_t) &dummy->regs.psw.mask) {
213 /* Return a clean psw mask. */
214 tmp &= PSW_MASK_USER | PSW_MASK_RI;
215 tmp |= PSW_USER_BITS;
216 }
217
218 } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
219 /*
220 * access registers are stored in the thread structure
221 */
222 offset = addr - (addr_t) &dummy->regs.acrs;
223 /*
224 * Very special case: old & broken 64 bit gdb reading
225 * from acrs[15]. Result is a 64 bit value. Read the
226 * 32 bit acrs[15] value and shift it by 32. Sick...
227 */
228 if (addr == (addr_t) &dummy->regs.acrs[15])
229 tmp = ((unsigned long) child->thread.acrs[15]) << 32;
230 else
231 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
232
233 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
234 /*
235 * orig_gpr2 is stored on the kernel stack
236 */
237 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
238
239 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
240 /*
241 * prevent reads of padding hole between
242 * orig_gpr2 and fp_regs on s390.
243 */
244 tmp = 0;
245
246 } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
247 /*
248 * floating point control reg. is in the thread structure
249 */
250 tmp = child->thread.fpu.fpc;
251 tmp <<= BITS_PER_LONG - 32;
252
253 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
254 /*
255 * floating point regs. are either in child->thread.fpu
256 * or the child->thread.fpu.vxrs array
257 */
258 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
259 if (MACHINE_HAS_VX)
260 tmp = *(addr_t *)
261 ((addr_t) child->thread.fpu.vxrs + 2*offset);
262 else
263 tmp = *(addr_t *)
264 ((addr_t) child->thread.fpu.fprs + offset);
265
266 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
267 /*
268 * Handle access to the per_info structure.
269 */
270 addr -= (addr_t) &dummy->regs.per_info;
271 tmp = __peek_user_per(child, addr);
272
273 } else
274 tmp = 0;
275
276 return tmp;
277}
278
279static int
280peek_user(struct task_struct *child, addr_t addr, addr_t data)
281{
282 addr_t tmp, mask;
283
284 /*
285 * Stupid gdb peeks/pokes the access registers in 64 bit with
286 * an alignment of 4. Programmers from hell...
287 */
288 mask = __ADDR_MASK;
289 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
290 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
291 mask = 3;
292 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
293 return -EIO;
294
295 tmp = __peek_user(child, addr);
296 return put_user(tmp, (addr_t __user *) data);
297}
298
299static inline void __poke_user_per(struct task_struct *child,
300 addr_t addr, addr_t data)
301{
302 struct per_struct_kernel *dummy = NULL;
303
304 /*
305 * There are only three fields in the per_info struct that the
306 * debugger user can write to.
307 * 1) cr9: the debugger wants to set a new PER event mask
308 * 2) starting_addr: the debugger wants to set a new starting
309 * address to use with the PER event mask.
310 * 3) ending_addr: the debugger wants to set a new ending
311 * address to use with the PER event mask.
312 * The user specified PER event mask and the start and end
313 * addresses are used only if single stepping is not in effect.
314 * Writes to any other field in per_info are ignored.
315 */
316 if (addr == (addr_t) &dummy->cr9)
317 /* PER event mask of the user specified per set. */
318 child->thread.per_user.control =
319 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
320 else if (addr == (addr_t) &dummy->starting_addr)
321 /* Starting address of the user specified per set. */
322 child->thread.per_user.start = data;
323 else if (addr == (addr_t) &dummy->ending_addr)
324 /* Ending address of the user specified per set. */
325 child->thread.per_user.end = data;
326}
327
328/*
329 * Write a word to the user area of a process at location addr. This
330 * operation does have an additional problem compared to peek_user.
331 * Stores to the program status word and on the floating point
332 * control register needs to get checked for validity.
333 */
334static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
335{
336 struct user *dummy = NULL;
337 addr_t offset;
338
339 if (addr < (addr_t) &dummy->regs.acrs) {
340 /*
341 * psw and gprs are stored on the stack
342 */
343 if (addr == (addr_t) &dummy->regs.psw.mask) {
344 unsigned long mask = PSW_MASK_USER;
345
346 mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
347 if ((data ^ PSW_USER_BITS) & ~mask)
348 /* Invalid psw mask. */
349 return -EINVAL;
350 if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
351 /* Invalid address-space-control bits */
352 return -EINVAL;
353 if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
354 /* Invalid addressing mode bits */
355 return -EINVAL;
356 }
357 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
358
359 } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
360 /*
361 * access registers are stored in the thread structure
362 */
363 offset = addr - (addr_t) &dummy->regs.acrs;
364 /*
365 * Very special case: old & broken 64 bit gdb writing
366 * to acrs[15] with a 64 bit value. Ignore the lower
367 * half of the value and write the upper 32 bit to
368 * acrs[15]. Sick...
369 */
370 if (addr == (addr_t) &dummy->regs.acrs[15])
371 child->thread.acrs[15] = (unsigned int) (data >> 32);
372 else
373 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
374
375 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
376 /*
377 * orig_gpr2 is stored on the kernel stack
378 */
379 task_pt_regs(child)->orig_gpr2 = data;
380
381 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
382 /*
383 * prevent writes of padding hole between
384 * orig_gpr2 and fp_regs on s390.
385 */
386 return 0;
387
388 } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
389 /*
390 * floating point control reg. is in the thread structure
391 */
392 if ((unsigned int) data != 0 ||
393 test_fp_ctl(data >> (BITS_PER_LONG - 32)))
394 return -EINVAL;
395 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
396
397 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
398 /*
399 * floating point regs. are either in child->thread.fpu
400 * or the child->thread.fpu.vxrs array
401 */
402 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
403 if (MACHINE_HAS_VX)
404 *(addr_t *)((addr_t)
405 child->thread.fpu.vxrs + 2*offset) = data;
406 else
407 *(addr_t *)((addr_t)
408 child->thread.fpu.fprs + offset) = data;
409
410 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
411 /*
412 * Handle access to the per_info structure.
413 */
414 addr -= (addr_t) &dummy->regs.per_info;
415 __poke_user_per(child, addr, data);
416
417 }
418
419 return 0;
420}
421
422static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
423{
424 addr_t mask;
425
426 /*
427 * Stupid gdb peeks/pokes the access registers in 64 bit with
428 * an alignment of 4. Programmers from hell indeed...
429 */
430 mask = __ADDR_MASK;
431 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
432 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
433 mask = 3;
434 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
435 return -EIO;
436
437 return __poke_user(child, addr, data);
438}
439
440long arch_ptrace(struct task_struct *child, long request,
441 unsigned long addr, unsigned long data)
442{
443 ptrace_area parea;
444 int copied, ret;
445
446 switch (request) {
447 case PTRACE_PEEKUSR:
448 /* read the word at location addr in the USER area. */
449 return peek_user(child, addr, data);
450
451 case PTRACE_POKEUSR:
452 /* write the word at location addr in the USER area */
453 return poke_user(child, addr, data);
454
455 case PTRACE_PEEKUSR_AREA:
456 case PTRACE_POKEUSR_AREA:
457 if (copy_from_user(&parea, (void __force __user *) addr,
458 sizeof(parea)))
459 return -EFAULT;
460 addr = parea.kernel_addr;
461 data = parea.process_addr;
462 copied = 0;
463 while (copied < parea.len) {
464 if (request == PTRACE_PEEKUSR_AREA)
465 ret = peek_user(child, addr, data);
466 else {
467 addr_t utmp;
468 if (get_user(utmp,
469 (addr_t __force __user *) data))
470 return -EFAULT;
471 ret = poke_user(child, addr, utmp);
472 }
473 if (ret)
474 return ret;
475 addr += sizeof(unsigned long);
476 data += sizeof(unsigned long);
477 copied += sizeof(unsigned long);
478 }
479 return 0;
480 case PTRACE_GET_LAST_BREAK:
481 put_user(child->thread.last_break,
482 (unsigned long __user *) data);
483 return 0;
484 case PTRACE_ENABLE_TE:
485 if (!MACHINE_HAS_TE)
486 return -EIO;
487 child->thread.per_flags &= ~PER_FLAG_NO_TE;
488 return 0;
489 case PTRACE_DISABLE_TE:
490 if (!MACHINE_HAS_TE)
491 return -EIO;
492 child->thread.per_flags |= PER_FLAG_NO_TE;
493 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
494 return 0;
495 case PTRACE_TE_ABORT_RAND:
496 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
497 return -EIO;
498 switch (data) {
499 case 0UL:
500 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
501 break;
502 case 1UL:
503 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
504 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
505 break;
506 case 2UL:
507 child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
508 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
509 break;
510 default:
511 return -EINVAL;
512 }
513 return 0;
514 default:
515 return ptrace_request(child, request, addr, data);
516 }
517}
518
519#ifdef CONFIG_COMPAT
520/*
521 * Now the fun part starts... a 31 bit program running in the
522 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
523 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
524 * to handle, the difference to the 64 bit versions of the requests
525 * is that the access is done in multiples of 4 byte instead of
526 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
527 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
528 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
529 * is a 31 bit program too, the content of struct user can be
530 * emulated. A 31 bit program peeking into the struct user of
531 * a 64 bit program is a no-no.
532 */
533
534/*
535 * Same as peek_user_per but for a 31 bit program.
536 */
537static inline __u32 __peek_user_per_compat(struct task_struct *child,
538 addr_t addr)
539{
540 struct compat_per_struct_kernel *dummy32 = NULL;
541
542 if (addr == (addr_t) &dummy32->cr9)
543 /* Control bits of the active per set. */
544 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
545 PER_EVENT_IFETCH : child->thread.per_user.control;
546 else if (addr == (addr_t) &dummy32->cr10)
547 /* Start address of the active per set. */
548 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
549 0 : child->thread.per_user.start;
550 else if (addr == (addr_t) &dummy32->cr11)
551 /* End address of the active per set. */
552 return test_thread_flag(TIF_SINGLE_STEP) ?
553 PSW32_ADDR_INSN : child->thread.per_user.end;
554 else if (addr == (addr_t) &dummy32->bits)
555 /* Single-step bit. */
556 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
557 0x80000000 : 0;
558 else if (addr == (addr_t) &dummy32->starting_addr)
559 /* Start address of the user specified per set. */
560 return (__u32) child->thread.per_user.start;
561 else if (addr == (addr_t) &dummy32->ending_addr)
562 /* End address of the user specified per set. */
563 return (__u32) child->thread.per_user.end;
564 else if (addr == (addr_t) &dummy32->perc_atmid)
565 /* PER code, ATMID and AI of the last PER trap */
566 return (__u32) child->thread.per_event.cause << 16;
567 else if (addr == (addr_t) &dummy32->address)
568 /* Address of the last PER trap */
569 return (__u32) child->thread.per_event.address;
570 else if (addr == (addr_t) &dummy32->access_id)
571 /* Access id of the last PER trap */
572 return (__u32) child->thread.per_event.paid << 24;
573 return 0;
574}
575
576/*
577 * Same as peek_user but for a 31 bit program.
578 */
579static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
580{
581 struct compat_user *dummy32 = NULL;
582 addr_t offset;
583 __u32 tmp;
584
585 if (addr < (addr_t) &dummy32->regs.acrs) {
586 struct pt_regs *regs = task_pt_regs(child);
587 /*
588 * psw and gprs are stored on the stack
589 */
590 if (addr == (addr_t) &dummy32->regs.psw.mask) {
591 /* Fake a 31 bit psw mask. */
592 tmp = (__u32)(regs->psw.mask >> 32);
593 tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
594 tmp |= PSW32_USER_BITS;
595 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
596 /* Fake a 31 bit psw address. */
597 tmp = (__u32) regs->psw.addr |
598 (__u32)(regs->psw.mask & PSW_MASK_BA);
599 } else {
600 /* gpr 0-15 */
601 tmp = *(__u32 *)((addr_t) ®s->psw + addr*2 + 4);
602 }
603 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
604 /*
605 * access registers are stored in the thread structure
606 */
607 offset = addr - (addr_t) &dummy32->regs.acrs;
608 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
609
610 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
611 /*
612 * orig_gpr2 is stored on the kernel stack
613 */
614 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
615
616 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
617 /*
618 * prevent reads of padding hole between
619 * orig_gpr2 and fp_regs on s390.
620 */
621 tmp = 0;
622
623 } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
624 /*
625 * floating point control reg. is in the thread structure
626 */
627 tmp = child->thread.fpu.fpc;
628
629 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
630 /*
631 * floating point regs. are either in child->thread.fpu
632 * or the child->thread.fpu.vxrs array
633 */
634 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
635 if (MACHINE_HAS_VX)
636 tmp = *(__u32 *)
637 ((addr_t) child->thread.fpu.vxrs + 2*offset);
638 else
639 tmp = *(__u32 *)
640 ((addr_t) child->thread.fpu.fprs + offset);
641
642 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
643 /*
644 * Handle access to the per_info structure.
645 */
646 addr -= (addr_t) &dummy32->regs.per_info;
647 tmp = __peek_user_per_compat(child, addr);
648
649 } else
650 tmp = 0;
651
652 return tmp;
653}
654
655static int peek_user_compat(struct task_struct *child,
656 addr_t addr, addr_t data)
657{
658 __u32 tmp;
659
660 if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
661 return -EIO;
662
663 tmp = __peek_user_compat(child, addr);
664 return put_user(tmp, (__u32 __user *) data);
665}
666
667/*
668 * Same as poke_user_per but for a 31 bit program.
669 */
670static inline void __poke_user_per_compat(struct task_struct *child,
671 addr_t addr, __u32 data)
672{
673 struct compat_per_struct_kernel *dummy32 = NULL;
674
675 if (addr == (addr_t) &dummy32->cr9)
676 /* PER event mask of the user specified per set. */
677 child->thread.per_user.control =
678 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
679 else if (addr == (addr_t) &dummy32->starting_addr)
680 /* Starting address of the user specified per set. */
681 child->thread.per_user.start = data;
682 else if (addr == (addr_t) &dummy32->ending_addr)
683 /* Ending address of the user specified per set. */
684 child->thread.per_user.end = data;
685}
686
687/*
688 * Same as poke_user but for a 31 bit program.
689 */
690static int __poke_user_compat(struct task_struct *child,
691 addr_t addr, addr_t data)
692{
693 struct compat_user *dummy32 = NULL;
694 __u32 tmp = (__u32) data;
695 addr_t offset;
696
697 if (addr < (addr_t) &dummy32->regs.acrs) {
698 struct pt_regs *regs = task_pt_regs(child);
699 /*
700 * psw, gprs, acrs and orig_gpr2 are stored on the stack
701 */
702 if (addr == (addr_t) &dummy32->regs.psw.mask) {
703 __u32 mask = PSW32_MASK_USER;
704
705 mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
706 /* Build a 64 bit psw mask from 31 bit mask. */
707 if ((tmp ^ PSW32_USER_BITS) & ~mask)
708 /* Invalid psw mask. */
709 return -EINVAL;
710 if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
711 /* Invalid address-space-control bits */
712 return -EINVAL;
713 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
714 (regs->psw.mask & PSW_MASK_BA) |
715 (__u64)(tmp & mask) << 32;
716 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
717 /* Build a 64 bit psw address from 31 bit address. */
718 regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
719 /* Transfer 31 bit amode bit to psw mask. */
720 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
721 (__u64)(tmp & PSW32_ADDR_AMODE);
722 } else {
723 /* gpr 0-15 */
724 *(__u32*)((addr_t) ®s->psw + addr*2 + 4) = tmp;
725 }
726 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
727 /*
728 * access registers are stored in the thread structure
729 */
730 offset = addr - (addr_t) &dummy32->regs.acrs;
731 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
732
733 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
734 /*
735 * orig_gpr2 is stored on the kernel stack
736 */
737 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
738
739 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
740 /*
741 * prevent writess of padding hole between
742 * orig_gpr2 and fp_regs on s390.
743 */
744 return 0;
745
746 } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
747 /*
748 * floating point control reg. is in the thread structure
749 */
750 if (test_fp_ctl(tmp))
751 return -EINVAL;
752 child->thread.fpu.fpc = data;
753
754 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
755 /*
756 * floating point regs. are either in child->thread.fpu
757 * or the child->thread.fpu.vxrs array
758 */
759 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
760 if (MACHINE_HAS_VX)
761 *(__u32 *)((addr_t)
762 child->thread.fpu.vxrs + 2*offset) = tmp;
763 else
764 *(__u32 *)((addr_t)
765 child->thread.fpu.fprs + offset) = tmp;
766
767 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
768 /*
769 * Handle access to the per_info structure.
770 */
771 addr -= (addr_t) &dummy32->regs.per_info;
772 __poke_user_per_compat(child, addr, data);
773 }
774
775 return 0;
776}
777
778static int poke_user_compat(struct task_struct *child,
779 addr_t addr, addr_t data)
780{
781 if (!is_compat_task() || (addr & 3) ||
782 addr > sizeof(struct compat_user) - 3)
783 return -EIO;
784
785 return __poke_user_compat(child, addr, data);
786}
787
788long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
789 compat_ulong_t caddr, compat_ulong_t cdata)
790{
791 unsigned long addr = caddr;
792 unsigned long data = cdata;
793 compat_ptrace_area parea;
794 int copied, ret;
795
796 switch (request) {
797 case PTRACE_PEEKUSR:
798 /* read the word at location addr in the USER area. */
799 return peek_user_compat(child, addr, data);
800
801 case PTRACE_POKEUSR:
802 /* write the word at location addr in the USER area */
803 return poke_user_compat(child, addr, data);
804
805 case PTRACE_PEEKUSR_AREA:
806 case PTRACE_POKEUSR_AREA:
807 if (copy_from_user(&parea, (void __force __user *) addr,
808 sizeof(parea)))
809 return -EFAULT;
810 addr = parea.kernel_addr;
811 data = parea.process_addr;
812 copied = 0;
813 while (copied < parea.len) {
814 if (request == PTRACE_PEEKUSR_AREA)
815 ret = peek_user_compat(child, addr, data);
816 else {
817 __u32 utmp;
818 if (get_user(utmp,
819 (__u32 __force __user *) data))
820 return -EFAULT;
821 ret = poke_user_compat(child, addr, utmp);
822 }
823 if (ret)
824 return ret;
825 addr += sizeof(unsigned int);
826 data += sizeof(unsigned int);
827 copied += sizeof(unsigned int);
828 }
829 return 0;
830 case PTRACE_GET_LAST_BREAK:
831 put_user(child->thread.last_break,
832 (unsigned int __user *) data);
833 return 0;
834 }
835 return compat_ptrace_request(child, request, addr, data);
836}
837#endif
838
839asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
840{
841 unsigned long mask = -1UL;
842
843 /*
844 * The sysc_tracesys code in entry.S stored the system
845 * call number to gprs[2].
846 */
847 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
848 (tracehook_report_syscall_entry(regs) ||
849 regs->gprs[2] >= NR_syscalls)) {
850 /*
851 * Tracing decided this syscall should not happen or the
852 * debugger stored an invalid system call number. Skip
853 * the system call and the system call restart handling.
854 */
855 clear_pt_regs_flag(regs, PIF_SYSCALL);
856 return -1;
857 }
858
859 /* Do the secure computing check after ptrace. */
860 if (secure_computing(NULL)) {
861 /* seccomp failures shouldn't expose any additional code. */
862 return -1;
863 }
864
865 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
866 trace_sys_enter(regs, regs->gprs[2]);
867
868 if (is_compat_task())
869 mask = 0xffffffff;
870
871 audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
872 regs->gprs[3] &mask, regs->gprs[4] &mask,
873 regs->gprs[5] &mask);
874
875 return regs->gprs[2];
876}
877
878asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
879{
880 audit_syscall_exit(regs);
881
882 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
883 trace_sys_exit(regs, regs->gprs[2]);
884
885 if (test_thread_flag(TIF_SYSCALL_TRACE))
886 tracehook_report_syscall_exit(regs, 0);
887}
888
889/*
890 * user_regset definitions.
891 */
892
893static int s390_regs_get(struct task_struct *target,
894 const struct user_regset *regset,
895 unsigned int pos, unsigned int count,
896 void *kbuf, void __user *ubuf)
897{
898 if (target == current)
899 save_access_regs(target->thread.acrs);
900
901 if (kbuf) {
902 unsigned long *k = kbuf;
903 while (count > 0) {
904 *k++ = __peek_user(target, pos);
905 count -= sizeof(*k);
906 pos += sizeof(*k);
907 }
908 } else {
909 unsigned long __user *u = ubuf;
910 while (count > 0) {
911 if (__put_user(__peek_user(target, pos), u++))
912 return -EFAULT;
913 count -= sizeof(*u);
914 pos += sizeof(*u);
915 }
916 }
917 return 0;
918}
919
920static int s390_regs_set(struct task_struct *target,
921 const struct user_regset *regset,
922 unsigned int pos, unsigned int count,
923 const void *kbuf, const void __user *ubuf)
924{
925 int rc = 0;
926
927 if (target == current)
928 save_access_regs(target->thread.acrs);
929
930 if (kbuf) {
931 const unsigned long *k = kbuf;
932 while (count > 0 && !rc) {
933 rc = __poke_user(target, pos, *k++);
934 count -= sizeof(*k);
935 pos += sizeof(*k);
936 }
937 } else {
938 const unsigned long __user *u = ubuf;
939 while (count > 0 && !rc) {
940 unsigned long word;
941 rc = __get_user(word, u++);
942 if (rc)
943 break;
944 rc = __poke_user(target, pos, word);
945 count -= sizeof(*u);
946 pos += sizeof(*u);
947 }
948 }
949
950 if (rc == 0 && target == current)
951 restore_access_regs(target->thread.acrs);
952
953 return rc;
954}
955
956static int s390_fpregs_get(struct task_struct *target,
957 const struct user_regset *regset, unsigned int pos,
958 unsigned int count, void *kbuf, void __user *ubuf)
959{
960 _s390_fp_regs fp_regs;
961
962 if (target == current)
963 save_fpu_regs();
964
965 fp_regs.fpc = target->thread.fpu.fpc;
966 fpregs_store(&fp_regs, &target->thread.fpu);
967
968 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
969 &fp_regs, 0, -1);
970}
971
972static int s390_fpregs_set(struct task_struct *target,
973 const struct user_regset *regset, unsigned int pos,
974 unsigned int count, const void *kbuf,
975 const void __user *ubuf)
976{
977 int rc = 0;
978 freg_t fprs[__NUM_FPRS];
979
980 if (target == current)
981 save_fpu_regs();
982
983 if (MACHINE_HAS_VX)
984 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
985 else
986 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
987
988 /* If setting FPC, must validate it first. */
989 if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
990 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
991 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
992 0, offsetof(s390_fp_regs, fprs));
993 if (rc)
994 return rc;
995 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
996 return -EINVAL;
997 target->thread.fpu.fpc = ufpc[0];
998 }
999
1000 if (rc == 0 && count > 0)
1001 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1002 fprs, offsetof(s390_fp_regs, fprs), -1);
1003 if (rc)
1004 return rc;
1005
1006 if (MACHINE_HAS_VX)
1007 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1008 else
1009 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1010
1011 return rc;
1012}
1013
1014static int s390_last_break_get(struct task_struct *target,
1015 const struct user_regset *regset,
1016 unsigned int pos, unsigned int count,
1017 void *kbuf, void __user *ubuf)
1018{
1019 if (count > 0) {
1020 if (kbuf) {
1021 unsigned long *k = kbuf;
1022 *k = target->thread.last_break;
1023 } else {
1024 unsigned long __user *u = ubuf;
1025 if (__put_user(target->thread.last_break, u))
1026 return -EFAULT;
1027 }
1028 }
1029 return 0;
1030}
1031
1032static int s390_last_break_set(struct task_struct *target,
1033 const struct user_regset *regset,
1034 unsigned int pos, unsigned int count,
1035 const void *kbuf, const void __user *ubuf)
1036{
1037 return 0;
1038}
1039
1040static int s390_tdb_get(struct task_struct *target,
1041 const struct user_regset *regset,
1042 unsigned int pos, unsigned int count,
1043 void *kbuf, void __user *ubuf)
1044{
1045 struct pt_regs *regs = task_pt_regs(target);
1046 unsigned char *data;
1047
1048 if (!(regs->int_code & 0x200))
1049 return -ENODATA;
1050 data = target->thread.trap_tdb;
1051 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1052}
1053
1054static int s390_tdb_set(struct task_struct *target,
1055 const struct user_regset *regset,
1056 unsigned int pos, unsigned int count,
1057 const void *kbuf, const void __user *ubuf)
1058{
1059 return 0;
1060}
1061
1062static int s390_vxrs_low_get(struct task_struct *target,
1063 const struct user_regset *regset,
1064 unsigned int pos, unsigned int count,
1065 void *kbuf, void __user *ubuf)
1066{
1067 __u64 vxrs[__NUM_VXRS_LOW];
1068 int i;
1069
1070 if (!MACHINE_HAS_VX)
1071 return -ENODEV;
1072 if (target == current)
1073 save_fpu_regs();
1074 for (i = 0; i < __NUM_VXRS_LOW; i++)
1075 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1076 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1077}
1078
1079static int s390_vxrs_low_set(struct task_struct *target,
1080 const struct user_regset *regset,
1081 unsigned int pos, unsigned int count,
1082 const void *kbuf, const void __user *ubuf)
1083{
1084 __u64 vxrs[__NUM_VXRS_LOW];
1085 int i, rc;
1086
1087 if (!MACHINE_HAS_VX)
1088 return -ENODEV;
1089 if (target == current)
1090 save_fpu_regs();
1091
1092 for (i = 0; i < __NUM_VXRS_LOW; i++)
1093 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1094
1095 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1096 if (rc == 0)
1097 for (i = 0; i < __NUM_VXRS_LOW; i++)
1098 *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1099
1100 return rc;
1101}
1102
1103static int s390_vxrs_high_get(struct task_struct *target,
1104 const struct user_regset *regset,
1105 unsigned int pos, unsigned int count,
1106 void *kbuf, void __user *ubuf)
1107{
1108 __vector128 vxrs[__NUM_VXRS_HIGH];
1109
1110 if (!MACHINE_HAS_VX)
1111 return -ENODEV;
1112 if (target == current)
1113 save_fpu_regs();
1114 memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1115
1116 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1117}
1118
1119static int s390_vxrs_high_set(struct task_struct *target,
1120 const struct user_regset *regset,
1121 unsigned int pos, unsigned int count,
1122 const void *kbuf, const void __user *ubuf)
1123{
1124 int rc;
1125
1126 if (!MACHINE_HAS_VX)
1127 return -ENODEV;
1128 if (target == current)
1129 save_fpu_regs();
1130
1131 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1132 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1133 return rc;
1134}
1135
1136static int s390_system_call_get(struct task_struct *target,
1137 const struct user_regset *regset,
1138 unsigned int pos, unsigned int count,
1139 void *kbuf, void __user *ubuf)
1140{
1141 unsigned int *data = &target->thread.system_call;
1142 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1143 data, 0, sizeof(unsigned int));
1144}
1145
1146static int s390_system_call_set(struct task_struct *target,
1147 const struct user_regset *regset,
1148 unsigned int pos, unsigned int count,
1149 const void *kbuf, const void __user *ubuf)
1150{
1151 unsigned int *data = &target->thread.system_call;
1152 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1153 data, 0, sizeof(unsigned int));
1154}
1155
1156static int s390_gs_cb_get(struct task_struct *target,
1157 const struct user_regset *regset,
1158 unsigned int pos, unsigned int count,
1159 void *kbuf, void __user *ubuf)
1160{
1161 struct gs_cb *data = target->thread.gs_cb;
1162
1163 if (!MACHINE_HAS_GS)
1164 return -ENODEV;
1165 if (!data)
1166 return -ENODATA;
1167 if (target == current)
1168 save_gs_cb(data);
1169 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1170 data, 0, sizeof(struct gs_cb));
1171}
1172
1173static int s390_gs_cb_set(struct task_struct *target,
1174 const struct user_regset *regset,
1175 unsigned int pos, unsigned int count,
1176 const void *kbuf, const void __user *ubuf)
1177{
1178 struct gs_cb gs_cb = { }, *data = NULL;
1179 int rc;
1180
1181 if (!MACHINE_HAS_GS)
1182 return -ENODEV;
1183 if (!target->thread.gs_cb) {
1184 data = kzalloc(sizeof(*data), GFP_KERNEL);
1185 if (!data)
1186 return -ENOMEM;
1187 }
1188 if (!target->thread.gs_cb)
1189 gs_cb.gsd = 25;
1190 else if (target == current)
1191 save_gs_cb(&gs_cb);
1192 else
1193 gs_cb = *target->thread.gs_cb;
1194 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1195 &gs_cb, 0, sizeof(gs_cb));
1196 if (rc) {
1197 kfree(data);
1198 return -EFAULT;
1199 }
1200 preempt_disable();
1201 if (!target->thread.gs_cb)
1202 target->thread.gs_cb = data;
1203 *target->thread.gs_cb = gs_cb;
1204 if (target == current) {
1205 __ctl_set_bit(2, 4);
1206 restore_gs_cb(target->thread.gs_cb);
1207 }
1208 preempt_enable();
1209 return rc;
1210}
1211
1212static int s390_gs_bc_get(struct task_struct *target,
1213 const struct user_regset *regset,
1214 unsigned int pos, unsigned int count,
1215 void *kbuf, void __user *ubuf)
1216{
1217 struct gs_cb *data = target->thread.gs_bc_cb;
1218
1219 if (!MACHINE_HAS_GS)
1220 return -ENODEV;
1221 if (!data)
1222 return -ENODATA;
1223 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1224 data, 0, sizeof(struct gs_cb));
1225}
1226
1227static int s390_gs_bc_set(struct task_struct *target,
1228 const struct user_regset *regset,
1229 unsigned int pos, unsigned int count,
1230 const void *kbuf, const void __user *ubuf)
1231{
1232 struct gs_cb *data = target->thread.gs_bc_cb;
1233
1234 if (!MACHINE_HAS_GS)
1235 return -ENODEV;
1236 if (!data) {
1237 data = kzalloc(sizeof(*data), GFP_KERNEL);
1238 if (!data)
1239 return -ENOMEM;
1240 target->thread.gs_bc_cb = data;
1241 }
1242 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1243 data, 0, sizeof(struct gs_cb));
1244}
1245
1246static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1247{
1248 return (cb->rca & 0x1f) == 0 &&
1249 (cb->roa & 0xfff) == 0 &&
1250 (cb->rla & 0xfff) == 0xfff &&
1251 cb->s == 1 &&
1252 cb->k == 1 &&
1253 cb->h == 0 &&
1254 cb->reserved1 == 0 &&
1255 cb->ps == 1 &&
1256 cb->qs == 0 &&
1257 cb->pc == 1 &&
1258 cb->qc == 0 &&
1259 cb->reserved2 == 0 &&
1260 cb->key == PAGE_DEFAULT_KEY &&
1261 cb->reserved3 == 0 &&
1262 cb->reserved4 == 0 &&
1263 cb->reserved5 == 0 &&
1264 cb->reserved6 == 0 &&
1265 cb->reserved7 == 0 &&
1266 cb->reserved8 == 0 &&
1267 cb->rla >= cb->roa &&
1268 cb->rca >= cb->roa &&
1269 cb->rca <= cb->rla+1 &&
1270 cb->m < 3;
1271}
1272
1273static int s390_runtime_instr_get(struct task_struct *target,
1274 const struct user_regset *regset,
1275 unsigned int pos, unsigned int count,
1276 void *kbuf, void __user *ubuf)
1277{
1278 struct runtime_instr_cb *data = target->thread.ri_cb;
1279
1280 if (!test_facility(64))
1281 return -ENODEV;
1282 if (!data)
1283 return -ENODATA;
1284
1285 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1286 data, 0, sizeof(struct runtime_instr_cb));
1287}
1288
1289static int s390_runtime_instr_set(struct task_struct *target,
1290 const struct user_regset *regset,
1291 unsigned int pos, unsigned int count,
1292 const void *kbuf, const void __user *ubuf)
1293{
1294 struct runtime_instr_cb ri_cb = { }, *data = NULL;
1295 int rc;
1296
1297 if (!test_facility(64))
1298 return -ENODEV;
1299
1300 if (!target->thread.ri_cb) {
1301 data = kzalloc(sizeof(*data), GFP_KERNEL);
1302 if (!data)
1303 return -ENOMEM;
1304 }
1305
1306 if (target->thread.ri_cb) {
1307 if (target == current)
1308 store_runtime_instr_cb(&ri_cb);
1309 else
1310 ri_cb = *target->thread.ri_cb;
1311 }
1312
1313 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1314 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1315 if (rc) {
1316 kfree(data);
1317 return -EFAULT;
1318 }
1319
1320 if (!is_ri_cb_valid(&ri_cb)) {
1321 kfree(data);
1322 return -EINVAL;
1323 }
1324
1325 preempt_disable();
1326 if (!target->thread.ri_cb)
1327 target->thread.ri_cb = data;
1328 *target->thread.ri_cb = ri_cb;
1329 if (target == current)
1330 load_runtime_instr_cb(target->thread.ri_cb);
1331 preempt_enable();
1332
1333 return 0;
1334}
1335
1336static const struct user_regset s390_regsets[] = {
1337 {
1338 .core_note_type = NT_PRSTATUS,
1339 .n = sizeof(s390_regs) / sizeof(long),
1340 .size = sizeof(long),
1341 .align = sizeof(long),
1342 .get = s390_regs_get,
1343 .set = s390_regs_set,
1344 },
1345 {
1346 .core_note_type = NT_PRFPREG,
1347 .n = sizeof(s390_fp_regs) / sizeof(long),
1348 .size = sizeof(long),
1349 .align = sizeof(long),
1350 .get = s390_fpregs_get,
1351 .set = s390_fpregs_set,
1352 },
1353 {
1354 .core_note_type = NT_S390_SYSTEM_CALL,
1355 .n = 1,
1356 .size = sizeof(unsigned int),
1357 .align = sizeof(unsigned int),
1358 .get = s390_system_call_get,
1359 .set = s390_system_call_set,
1360 },
1361 {
1362 .core_note_type = NT_S390_LAST_BREAK,
1363 .n = 1,
1364 .size = sizeof(long),
1365 .align = sizeof(long),
1366 .get = s390_last_break_get,
1367 .set = s390_last_break_set,
1368 },
1369 {
1370 .core_note_type = NT_S390_TDB,
1371 .n = 1,
1372 .size = 256,
1373 .align = 1,
1374 .get = s390_tdb_get,
1375 .set = s390_tdb_set,
1376 },
1377 {
1378 .core_note_type = NT_S390_VXRS_LOW,
1379 .n = __NUM_VXRS_LOW,
1380 .size = sizeof(__u64),
1381 .align = sizeof(__u64),
1382 .get = s390_vxrs_low_get,
1383 .set = s390_vxrs_low_set,
1384 },
1385 {
1386 .core_note_type = NT_S390_VXRS_HIGH,
1387 .n = __NUM_VXRS_HIGH,
1388 .size = sizeof(__vector128),
1389 .align = sizeof(__vector128),
1390 .get = s390_vxrs_high_get,
1391 .set = s390_vxrs_high_set,
1392 },
1393 {
1394 .core_note_type = NT_S390_GS_CB,
1395 .n = sizeof(struct gs_cb) / sizeof(__u64),
1396 .size = sizeof(__u64),
1397 .align = sizeof(__u64),
1398 .get = s390_gs_cb_get,
1399 .set = s390_gs_cb_set,
1400 },
1401 {
1402 .core_note_type = NT_S390_GS_BC,
1403 .n = sizeof(struct gs_cb) / sizeof(__u64),
1404 .size = sizeof(__u64),
1405 .align = sizeof(__u64),
1406 .get = s390_gs_bc_get,
1407 .set = s390_gs_bc_set,
1408 },
1409 {
1410 .core_note_type = NT_S390_RI_CB,
1411 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1412 .size = sizeof(__u64),
1413 .align = sizeof(__u64),
1414 .get = s390_runtime_instr_get,
1415 .set = s390_runtime_instr_set,
1416 },
1417};
1418
1419static const struct user_regset_view user_s390_view = {
1420 .name = UTS_MACHINE,
1421 .e_machine = EM_S390,
1422 .regsets = s390_regsets,
1423 .n = ARRAY_SIZE(s390_regsets)
1424};
1425
1426#ifdef CONFIG_COMPAT
1427static int s390_compat_regs_get(struct task_struct *target,
1428 const struct user_regset *regset,
1429 unsigned int pos, unsigned int count,
1430 void *kbuf, void __user *ubuf)
1431{
1432 if (target == current)
1433 save_access_regs(target->thread.acrs);
1434
1435 if (kbuf) {
1436 compat_ulong_t *k = kbuf;
1437 while (count > 0) {
1438 *k++ = __peek_user_compat(target, pos);
1439 count -= sizeof(*k);
1440 pos += sizeof(*k);
1441 }
1442 } else {
1443 compat_ulong_t __user *u = ubuf;
1444 while (count > 0) {
1445 if (__put_user(__peek_user_compat(target, pos), u++))
1446 return -EFAULT;
1447 count -= sizeof(*u);
1448 pos += sizeof(*u);
1449 }
1450 }
1451 return 0;
1452}
1453
1454static int s390_compat_regs_set(struct task_struct *target,
1455 const struct user_regset *regset,
1456 unsigned int pos, unsigned int count,
1457 const void *kbuf, const void __user *ubuf)
1458{
1459 int rc = 0;
1460
1461 if (target == current)
1462 save_access_regs(target->thread.acrs);
1463
1464 if (kbuf) {
1465 const compat_ulong_t *k = kbuf;
1466 while (count > 0 && !rc) {
1467 rc = __poke_user_compat(target, pos, *k++);
1468 count -= sizeof(*k);
1469 pos += sizeof(*k);
1470 }
1471 } else {
1472 const compat_ulong_t __user *u = ubuf;
1473 while (count > 0 && !rc) {
1474 compat_ulong_t word;
1475 rc = __get_user(word, u++);
1476 if (rc)
1477 break;
1478 rc = __poke_user_compat(target, pos, word);
1479 count -= sizeof(*u);
1480 pos += sizeof(*u);
1481 }
1482 }
1483
1484 if (rc == 0 && target == current)
1485 restore_access_regs(target->thread.acrs);
1486
1487 return rc;
1488}
1489
1490static int s390_compat_regs_high_get(struct task_struct *target,
1491 const struct user_regset *regset,
1492 unsigned int pos, unsigned int count,
1493 void *kbuf, void __user *ubuf)
1494{
1495 compat_ulong_t *gprs_high;
1496
1497 gprs_high = (compat_ulong_t *)
1498 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1499 if (kbuf) {
1500 compat_ulong_t *k = kbuf;
1501 while (count > 0) {
1502 *k++ = *gprs_high;
1503 gprs_high += 2;
1504 count -= sizeof(*k);
1505 }
1506 } else {
1507 compat_ulong_t __user *u = ubuf;
1508 while (count > 0) {
1509 if (__put_user(*gprs_high, u++))
1510 return -EFAULT;
1511 gprs_high += 2;
1512 count -= sizeof(*u);
1513 }
1514 }
1515 return 0;
1516}
1517
1518static int s390_compat_regs_high_set(struct task_struct *target,
1519 const struct user_regset *regset,
1520 unsigned int pos, unsigned int count,
1521 const void *kbuf, const void __user *ubuf)
1522{
1523 compat_ulong_t *gprs_high;
1524 int rc = 0;
1525
1526 gprs_high = (compat_ulong_t *)
1527 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1528 if (kbuf) {
1529 const compat_ulong_t *k = kbuf;
1530 while (count > 0) {
1531 *gprs_high = *k++;
1532 *gprs_high += 2;
1533 count -= sizeof(*k);
1534 }
1535 } else {
1536 const compat_ulong_t __user *u = ubuf;
1537 while (count > 0 && !rc) {
1538 unsigned long word;
1539 rc = __get_user(word, u++);
1540 if (rc)
1541 break;
1542 *gprs_high = word;
1543 *gprs_high += 2;
1544 count -= sizeof(*u);
1545 }
1546 }
1547
1548 return rc;
1549}
1550
1551static int s390_compat_last_break_get(struct task_struct *target,
1552 const struct user_regset *regset,
1553 unsigned int pos, unsigned int count,
1554 void *kbuf, void __user *ubuf)
1555{
1556 compat_ulong_t last_break;
1557
1558 if (count > 0) {
1559 last_break = target->thread.last_break;
1560 if (kbuf) {
1561 unsigned long *k = kbuf;
1562 *k = last_break;
1563 } else {
1564 unsigned long __user *u = ubuf;
1565 if (__put_user(last_break, u))
1566 return -EFAULT;
1567 }
1568 }
1569 return 0;
1570}
1571
1572static int s390_compat_last_break_set(struct task_struct *target,
1573 const struct user_regset *regset,
1574 unsigned int pos, unsigned int count,
1575 const void *kbuf, const void __user *ubuf)
1576{
1577 return 0;
1578}
1579
1580static const struct user_regset s390_compat_regsets[] = {
1581 {
1582 .core_note_type = NT_PRSTATUS,
1583 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1584 .size = sizeof(compat_long_t),
1585 .align = sizeof(compat_long_t),
1586 .get = s390_compat_regs_get,
1587 .set = s390_compat_regs_set,
1588 },
1589 {
1590 .core_note_type = NT_PRFPREG,
1591 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1592 .size = sizeof(compat_long_t),
1593 .align = sizeof(compat_long_t),
1594 .get = s390_fpregs_get,
1595 .set = s390_fpregs_set,
1596 },
1597 {
1598 .core_note_type = NT_S390_SYSTEM_CALL,
1599 .n = 1,
1600 .size = sizeof(compat_uint_t),
1601 .align = sizeof(compat_uint_t),
1602 .get = s390_system_call_get,
1603 .set = s390_system_call_set,
1604 },
1605 {
1606 .core_note_type = NT_S390_LAST_BREAK,
1607 .n = 1,
1608 .size = sizeof(long),
1609 .align = sizeof(long),
1610 .get = s390_compat_last_break_get,
1611 .set = s390_compat_last_break_set,
1612 },
1613 {
1614 .core_note_type = NT_S390_TDB,
1615 .n = 1,
1616 .size = 256,
1617 .align = 1,
1618 .get = s390_tdb_get,
1619 .set = s390_tdb_set,
1620 },
1621 {
1622 .core_note_type = NT_S390_VXRS_LOW,
1623 .n = __NUM_VXRS_LOW,
1624 .size = sizeof(__u64),
1625 .align = sizeof(__u64),
1626 .get = s390_vxrs_low_get,
1627 .set = s390_vxrs_low_set,
1628 },
1629 {
1630 .core_note_type = NT_S390_VXRS_HIGH,
1631 .n = __NUM_VXRS_HIGH,
1632 .size = sizeof(__vector128),
1633 .align = sizeof(__vector128),
1634 .get = s390_vxrs_high_get,
1635 .set = s390_vxrs_high_set,
1636 },
1637 {
1638 .core_note_type = NT_S390_HIGH_GPRS,
1639 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1640 .size = sizeof(compat_long_t),
1641 .align = sizeof(compat_long_t),
1642 .get = s390_compat_regs_high_get,
1643 .set = s390_compat_regs_high_set,
1644 },
1645 {
1646 .core_note_type = NT_S390_GS_CB,
1647 .n = sizeof(struct gs_cb) / sizeof(__u64),
1648 .size = sizeof(__u64),
1649 .align = sizeof(__u64),
1650 .get = s390_gs_cb_get,
1651 .set = s390_gs_cb_set,
1652 },
1653 {
1654 .core_note_type = NT_S390_GS_BC,
1655 .n = sizeof(struct gs_cb) / sizeof(__u64),
1656 .size = sizeof(__u64),
1657 .align = sizeof(__u64),
1658 .get = s390_gs_bc_get,
1659 .set = s390_gs_bc_set,
1660 },
1661 {
1662 .core_note_type = NT_S390_RI_CB,
1663 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1664 .size = sizeof(__u64),
1665 .align = sizeof(__u64),
1666 .get = s390_runtime_instr_get,
1667 .set = s390_runtime_instr_set,
1668 },
1669};
1670
1671static const struct user_regset_view user_s390_compat_view = {
1672 .name = "s390",
1673 .e_machine = EM_S390,
1674 .regsets = s390_compat_regsets,
1675 .n = ARRAY_SIZE(s390_compat_regsets)
1676};
1677#endif
1678
1679const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1680{
1681#ifdef CONFIG_COMPAT
1682 if (test_tsk_thread_flag(task, TIF_31BIT))
1683 return &user_s390_compat_view;
1684#endif
1685 return &user_s390_view;
1686}
1687
1688static const char *gpr_names[NUM_GPRS] = {
1689 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
1690 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1691};
1692
1693unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1694{
1695 if (offset >= NUM_GPRS)
1696 return 0;
1697 return regs->gprs[offset];
1698}
1699
1700int regs_query_register_offset(const char *name)
1701{
1702 unsigned long offset;
1703
1704 if (!name || *name != 'r')
1705 return -EINVAL;
1706 if (kstrtoul(name + 1, 10, &offset))
1707 return -EINVAL;
1708 if (offset >= NUM_GPRS)
1709 return -EINVAL;
1710 return offset;
1711}
1712
1713const char *regs_query_register_name(unsigned int offset)
1714{
1715 if (offset >= NUM_GPRS)
1716 return NULL;
1717 return gpr_names[offset];
1718}
1719
1720static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1721{
1722 unsigned long ksp = kernel_stack_pointer(regs);
1723
1724 return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1725}
1726
1727/**
1728 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1729 * @regs:pt_regs which contains kernel stack pointer.
1730 * @n:stack entry number.
1731 *
1732 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1733 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1734 * this returns 0.
1735 */
1736unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1737{
1738 unsigned long addr;
1739
1740 addr = kernel_stack_pointer(regs) + n * sizeof(long);
1741 if (!regs_within_kernel_stack(regs, addr))
1742 return 0;
1743 return *(unsigned long *)addr;
1744}
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}