1 /*
2 * Ptrace user space interface.
3 *
4 * Copyright IBM Corp. 1999,2010
5 * Author(s): Denis Joseph Barrow
6 * Martin Schwidefsky (schwidefsky@de.ibm.com)
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/errno.h>
14 #include <linux/ptrace.h>
15 #include <linux/user.h>
16 #include <linux/security.h>
17 #include <linux/audit.h>
18 #include <linux/signal.h>
19 #include <linux/elf.h>
20 #include <linux/regset.h>
21 #include <linux/tracehook.h>
22 #include <linux/seccomp.h>
23 #include <trace/syscall.h>
24 #include <asm/compat.h>
25 #include <asm/segment.h>
26 #include <asm/page.h>
27 #include <asm/pgtable.h>
28 #include <asm/pgalloc.h>
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <asm/unistd.h>
32 #include "entry.h"
33
34 #ifdef CONFIG_COMPAT
35 #include "compat_ptrace.h"
36 #endif
37
38 #define CREATE_TRACE_POINTS
39 #include <trace/events/syscalls.h>
40
41 enum s390_regset {
42 REGSET_GENERAL,
43 REGSET_FP,
44 REGSET_LAST_BREAK,
45 REGSET_GENERAL_EXTENDED,
46 };
47
update_per_regs(struct task_struct * task)48 void update_per_regs(struct task_struct *task)
49 {
50 static const struct per_regs per_single_step = {
51 .control = PER_EVENT_IFETCH,
52 .start = 0,
53 .end = PSW_ADDR_INSN,
54 };
55 struct pt_regs *regs = task_pt_regs(task);
56 struct thread_struct *thread = &task->thread;
57 const struct per_regs *new;
58 struct per_regs old;
59
60 /* TIF_SINGLE_STEP overrides the user specified PER registers. */
61 new = test_tsk_thread_flag(task, TIF_SINGLE_STEP) ?
62 &per_single_step : &thread->per_user;
63
64 /* Take care of the PER enablement bit in the PSW. */
65 if (!(new->control & PER_EVENT_MASK)) {
66 regs->psw.mask &= ~PSW_MASK_PER;
67 return;
68 }
69 regs->psw.mask |= PSW_MASK_PER;
70 __ctl_store(old, 9, 11);
71 if (memcmp(new, &old, sizeof(struct per_regs)) != 0)
72 __ctl_load(*new, 9, 11);
73 }
74
user_enable_single_step(struct task_struct * task)75 void user_enable_single_step(struct task_struct *task)
76 {
77 set_tsk_thread_flag(task, TIF_SINGLE_STEP);
78 if (task == current)
79 update_per_regs(task);
80 }
81
user_disable_single_step(struct task_struct * task)82 void user_disable_single_step(struct task_struct *task)
83 {
84 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
85 if (task == current)
86 update_per_regs(task);
87 }
88
89 /*
90 * Called by kernel/ptrace.c when detaching..
91 *
92 * Clear all debugging related fields.
93 */
ptrace_disable(struct task_struct * task)94 void ptrace_disable(struct task_struct *task)
95 {
96 memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
97 memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
98 clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
99 clear_tsk_thread_flag(task, TIF_PER_TRAP);
100 }
101
102 #ifndef CONFIG_64BIT
103 # define __ADDR_MASK 3
104 #else
105 # define __ADDR_MASK 7
106 #endif
107
__peek_user_per(struct task_struct * child,addr_t addr)108 static inline unsigned long __peek_user_per(struct task_struct *child,
109 addr_t addr)
110 {
111 struct per_struct_kernel *dummy = NULL;
112
113 if (addr == (addr_t) &dummy->cr9)
114 /* Control bits of the active per set. */
115 return test_thread_flag(TIF_SINGLE_STEP) ?
116 PER_EVENT_IFETCH : child->thread.per_user.control;
117 else if (addr == (addr_t) &dummy->cr10)
118 /* Start address of the active per set. */
119 return test_thread_flag(TIF_SINGLE_STEP) ?
120 0 : child->thread.per_user.start;
121 else if (addr == (addr_t) &dummy->cr11)
122 /* End address of the active per set. */
123 return test_thread_flag(TIF_SINGLE_STEP) ?
124 PSW_ADDR_INSN : child->thread.per_user.end;
125 else if (addr == (addr_t) &dummy->bits)
126 /* Single-step bit. */
127 return test_thread_flag(TIF_SINGLE_STEP) ?
128 (1UL << (BITS_PER_LONG - 1)) : 0;
129 else if (addr == (addr_t) &dummy->starting_addr)
130 /* Start address of the user specified per set. */
131 return child->thread.per_user.start;
132 else if (addr == (addr_t) &dummy->ending_addr)
133 /* End address of the user specified per set. */
134 return child->thread.per_user.end;
135 else if (addr == (addr_t) &dummy->perc_atmid)
136 /* PER code, ATMID and AI of the last PER trap */
137 return (unsigned long)
138 child->thread.per_event.cause << (BITS_PER_LONG - 16);
139 else if (addr == (addr_t) &dummy->address)
140 /* Address of the last PER trap */
141 return child->thread.per_event.address;
142 else if (addr == (addr_t) &dummy->access_id)
143 /* Access id of the last PER trap */
144 return (unsigned long)
145 child->thread.per_event.paid << (BITS_PER_LONG - 8);
146 return 0;
147 }
148
149 /*
150 * Read the word at offset addr from the user area of a process. The
151 * trouble here is that the information is littered over different
152 * locations. The process registers are found on the kernel stack,
153 * the floating point stuff and the trace settings are stored in
154 * the task structure. In addition the different structures in
155 * struct user contain pad bytes that should be read as zeroes.
156 * Lovely...
157 */
__peek_user(struct task_struct * child,addr_t addr)158 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
159 {
160 struct user *dummy = NULL;
161 addr_t offset, tmp;
162
163 if (addr < (addr_t) &dummy->regs.acrs) {
164 /*
165 * psw and gprs are stored on the stack
166 */
167 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
168 if (addr == (addr_t) &dummy->regs.psw.mask)
169 /* Remove per bit from user psw. */
170 tmp &= ~PSW_MASK_PER;
171
172 } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
173 /*
174 * access registers are stored in the thread structure
175 */
176 offset = addr - (addr_t) &dummy->regs.acrs;
177 #ifdef CONFIG_64BIT
178 /*
179 * Very special case: old & broken 64 bit gdb reading
180 * from acrs[15]. Result is a 64 bit value. Read the
181 * 32 bit acrs[15] value and shift it by 32. Sick...
182 */
183 if (addr == (addr_t) &dummy->regs.acrs[15])
184 tmp = ((unsigned long) child->thread.acrs[15]) << 32;
185 else
186 #endif
187 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
188
189 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
190 /*
191 * orig_gpr2 is stored on the kernel stack
192 */
193 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
194
195 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
196 /*
197 * prevent reads of padding hole between
198 * orig_gpr2 and fp_regs on s390.
199 */
200 tmp = 0;
201
202 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
203 /*
204 * floating point regs. are stored in the thread structure
205 */
206 offset = addr - (addr_t) &dummy->regs.fp_regs;
207 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
208 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
209 tmp &= (unsigned long) FPC_VALID_MASK
210 << (BITS_PER_LONG - 32);
211
212 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
213 /*
214 * Handle access to the per_info structure.
215 */
216 addr -= (addr_t) &dummy->regs.per_info;
217 tmp = __peek_user_per(child, addr);
218
219 } else
220 tmp = 0;
221
222 return tmp;
223 }
224
225 static int
peek_user(struct task_struct * child,addr_t addr,addr_t data)226 peek_user(struct task_struct *child, addr_t addr, addr_t data)
227 {
228 addr_t tmp, mask;
229
230 /*
231 * Stupid gdb peeks/pokes the access registers in 64 bit with
232 * an alignment of 4. Programmers from hell...
233 */
234 mask = __ADDR_MASK;
235 #ifdef CONFIG_64BIT
236 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
237 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
238 mask = 3;
239 #endif
240 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
241 return -EIO;
242
243 tmp = __peek_user(child, addr);
244 return put_user(tmp, (addr_t __user *) data);
245 }
246
__poke_user_per(struct task_struct * child,addr_t addr,addr_t data)247 static inline void __poke_user_per(struct task_struct *child,
248 addr_t addr, addr_t data)
249 {
250 struct per_struct_kernel *dummy = NULL;
251
252 /*
253 * There are only three fields in the per_info struct that the
254 * debugger user can write to.
255 * 1) cr9: the debugger wants to set a new PER event mask
256 * 2) starting_addr: the debugger wants to set a new starting
257 * address to use with the PER event mask.
258 * 3) ending_addr: the debugger wants to set a new ending
259 * address to use with the PER event mask.
260 * The user specified PER event mask and the start and end
261 * addresses are used only if single stepping is not in effect.
262 * Writes to any other field in per_info are ignored.
263 */
264 if (addr == (addr_t) &dummy->cr9)
265 /* PER event mask of the user specified per set. */
266 child->thread.per_user.control =
267 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
268 else if (addr == (addr_t) &dummy->starting_addr)
269 /* Starting address of the user specified per set. */
270 child->thread.per_user.start = data;
271 else if (addr == (addr_t) &dummy->ending_addr)
272 /* Ending address of the user specified per set. */
273 child->thread.per_user.end = data;
274 }
275
276 /*
277 * Write a word to the user area of a process at location addr. This
278 * operation does have an additional problem compared to peek_user.
279 * Stores to the program status word and on the floating point
280 * control register needs to get checked for validity.
281 */
__poke_user(struct task_struct * child,addr_t addr,addr_t data)282 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
283 {
284 struct user *dummy = NULL;
285 addr_t offset;
286
287 if (addr < (addr_t) &dummy->regs.acrs) {
288 /*
289 * psw and gprs are stored on the stack
290 */
291 if (addr == (addr_t) &dummy->regs.psw.mask &&
292 #ifdef CONFIG_COMPAT
293 data != PSW_MASK_MERGE(psw_user32_bits, data) &&
294 #endif
295 data != PSW_MASK_MERGE(psw_user_bits, data))
296 /* Invalid psw mask. */
297 return -EINVAL;
298 #ifndef CONFIG_64BIT
299 if (addr == (addr_t) &dummy->regs.psw.addr)
300 /* I'd like to reject addresses without the
301 high order bit but older gdb's rely on it */
302 data |= PSW_ADDR_AMODE;
303 #endif
304 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
305
306 } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
307 /*
308 * access registers are stored in the thread structure
309 */
310 offset = addr - (addr_t) &dummy->regs.acrs;
311 #ifdef CONFIG_64BIT
312 /*
313 * Very special case: old & broken 64 bit gdb writing
314 * to acrs[15] with a 64 bit value. Ignore the lower
315 * half of the value and write the upper 32 bit to
316 * acrs[15]. Sick...
317 */
318 if (addr == (addr_t) &dummy->regs.acrs[15])
319 child->thread.acrs[15] = (unsigned int) (data >> 32);
320 else
321 #endif
322 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
323
324 } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
325 /*
326 * orig_gpr2 is stored on the kernel stack
327 */
328 task_pt_regs(child)->orig_gpr2 = data;
329
330 } else if (addr < (addr_t) &dummy->regs.fp_regs) {
331 /*
332 * prevent writes of padding hole between
333 * orig_gpr2 and fp_regs on s390.
334 */
335 return 0;
336
337 } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
338 /*
339 * floating point regs. are stored in the thread structure
340 */
341 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
342 (data & ~((unsigned long) FPC_VALID_MASK
343 << (BITS_PER_LONG - 32))) != 0)
344 return -EINVAL;
345 offset = addr - (addr_t) &dummy->regs.fp_regs;
346 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
347
348 } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
349 /*
350 * Handle access to the per_info structure.
351 */
352 addr -= (addr_t) &dummy->regs.per_info;
353 __poke_user_per(child, addr, data);
354
355 }
356
357 return 0;
358 }
359
poke_user(struct task_struct * child,addr_t addr,addr_t data)360 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
361 {
362 addr_t mask;
363
364 /*
365 * Stupid gdb peeks/pokes the access registers in 64 bit with
366 * an alignment of 4. Programmers from hell indeed...
367 */
368 mask = __ADDR_MASK;
369 #ifdef CONFIG_64BIT
370 if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
371 addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
372 mask = 3;
373 #endif
374 if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
375 return -EIO;
376
377 return __poke_user(child, addr, data);
378 }
379
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)380 long arch_ptrace(struct task_struct *child, long request,
381 unsigned long addr, unsigned long data)
382 {
383 ptrace_area parea;
384 int copied, ret;
385
386 switch (request) {
387 case PTRACE_PEEKUSR:
388 /* read the word at location addr in the USER area. */
389 return peek_user(child, addr, data);
390
391 case PTRACE_POKEUSR:
392 /* write the word at location addr in the USER area */
393 return poke_user(child, addr, data);
394
395 case PTRACE_PEEKUSR_AREA:
396 case PTRACE_POKEUSR_AREA:
397 if (copy_from_user(&parea, (void __force __user *) addr,
398 sizeof(parea)))
399 return -EFAULT;
400 addr = parea.kernel_addr;
401 data = parea.process_addr;
402 copied = 0;
403 while (copied < parea.len) {
404 if (request == PTRACE_PEEKUSR_AREA)
405 ret = peek_user(child, addr, data);
406 else {
407 addr_t utmp;
408 if (get_user(utmp,
409 (addr_t __force __user *) data))
410 return -EFAULT;
411 ret = poke_user(child, addr, utmp);
412 }
413 if (ret)
414 return ret;
415 addr += sizeof(unsigned long);
416 data += sizeof(unsigned long);
417 copied += sizeof(unsigned long);
418 }
419 return 0;
420 case PTRACE_GET_LAST_BREAK:
421 put_user(task_thread_info(child)->last_break,
422 (unsigned long __user *) data);
423 return 0;
424 default:
425 /* Removing high order bit from addr (only for 31 bit). */
426 addr &= PSW_ADDR_INSN;
427 return ptrace_request(child, request, addr, data);
428 }
429 }
430
431 #ifdef CONFIG_COMPAT
432 /*
433 * Now the fun part starts... a 31 bit program running in the
434 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
435 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
436 * to handle, the difference to the 64 bit versions of the requests
437 * is that the access is done in multiples of 4 byte instead of
438 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
439 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
440 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
441 * is a 31 bit program too, the content of struct user can be
442 * emulated. A 31 bit program peeking into the struct user of
443 * a 64 bit program is a no-no.
444 */
445
446 /*
447 * Same as peek_user_per but for a 31 bit program.
448 */
__peek_user_per_compat(struct task_struct * child,addr_t addr)449 static inline __u32 __peek_user_per_compat(struct task_struct *child,
450 addr_t addr)
451 {
452 struct compat_per_struct_kernel *dummy32 = NULL;
453
454 if (addr == (addr_t) &dummy32->cr9)
455 /* Control bits of the active per set. */
456 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
457 PER_EVENT_IFETCH : child->thread.per_user.control;
458 else if (addr == (addr_t) &dummy32->cr10)
459 /* Start address of the active per set. */
460 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
461 0 : child->thread.per_user.start;
462 else if (addr == (addr_t) &dummy32->cr11)
463 /* End address of the active per set. */
464 return test_thread_flag(TIF_SINGLE_STEP) ?
465 PSW32_ADDR_INSN : child->thread.per_user.end;
466 else if (addr == (addr_t) &dummy32->bits)
467 /* Single-step bit. */
468 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
469 0x80000000 : 0;
470 else if (addr == (addr_t) &dummy32->starting_addr)
471 /* Start address of the user specified per set. */
472 return (__u32) child->thread.per_user.start;
473 else if (addr == (addr_t) &dummy32->ending_addr)
474 /* End address of the user specified per set. */
475 return (__u32) child->thread.per_user.end;
476 else if (addr == (addr_t) &dummy32->perc_atmid)
477 /* PER code, ATMID and AI of the last PER trap */
478 return (__u32) child->thread.per_event.cause << 16;
479 else if (addr == (addr_t) &dummy32->address)
480 /* Address of the last PER trap */
481 return (__u32) child->thread.per_event.address;
482 else if (addr == (addr_t) &dummy32->access_id)
483 /* Access id of the last PER trap */
484 return (__u32) child->thread.per_event.paid << 24;
485 return 0;
486 }
487
488 /*
489 * Same as peek_user but for a 31 bit program.
490 */
__peek_user_compat(struct task_struct * child,addr_t addr)491 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
492 {
493 struct compat_user *dummy32 = NULL;
494 addr_t offset;
495 __u32 tmp;
496
497 if (addr < (addr_t) &dummy32->regs.acrs) {
498 /*
499 * psw and gprs are stored on the stack
500 */
501 if (addr == (addr_t) &dummy32->regs.psw.mask) {
502 /* Fake a 31 bit psw mask. */
503 tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
504 tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
505 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
506 /* Fake a 31 bit psw address. */
507 tmp = (__u32) task_pt_regs(child)->psw.addr |
508 PSW32_ADDR_AMODE31;
509 } else {
510 /* gpr 0-15 */
511 tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
512 addr*2 + 4);
513 }
514 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
515 /*
516 * access registers are stored in the thread structure
517 */
518 offset = addr - (addr_t) &dummy32->regs.acrs;
519 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
520
521 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
522 /*
523 * orig_gpr2 is stored on the kernel stack
524 */
525 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
526
527 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
528 /*
529 * prevent reads of padding hole between
530 * orig_gpr2 and fp_regs on s390.
531 */
532 tmp = 0;
533
534 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
535 /*
536 * floating point regs. are stored in the thread structure
537 */
538 offset = addr - (addr_t) &dummy32->regs.fp_regs;
539 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
540
541 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
542 /*
543 * Handle access to the per_info structure.
544 */
545 addr -= (addr_t) &dummy32->regs.per_info;
546 tmp = __peek_user_per_compat(child, addr);
547
548 } else
549 tmp = 0;
550
551 return tmp;
552 }
553
peek_user_compat(struct task_struct * child,addr_t addr,addr_t data)554 static int peek_user_compat(struct task_struct *child,
555 addr_t addr, addr_t data)
556 {
557 __u32 tmp;
558
559 if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
560 return -EIO;
561
562 tmp = __peek_user_compat(child, addr);
563 return put_user(tmp, (__u32 __user *) data);
564 }
565
566 /*
567 * Same as poke_user_per but for a 31 bit program.
568 */
__poke_user_per_compat(struct task_struct * child,addr_t addr,__u32 data)569 static inline void __poke_user_per_compat(struct task_struct *child,
570 addr_t addr, __u32 data)
571 {
572 struct compat_per_struct_kernel *dummy32 = NULL;
573
574 if (addr == (addr_t) &dummy32->cr9)
575 /* PER event mask of the user specified per set. */
576 child->thread.per_user.control =
577 data & (PER_EVENT_MASK | PER_CONTROL_MASK);
578 else if (addr == (addr_t) &dummy32->starting_addr)
579 /* Starting address of the user specified per set. */
580 child->thread.per_user.start = data;
581 else if (addr == (addr_t) &dummy32->ending_addr)
582 /* Ending address of the user specified per set. */
583 child->thread.per_user.end = data;
584 }
585
586 /*
587 * Same as poke_user but for a 31 bit program.
588 */
__poke_user_compat(struct task_struct * child,addr_t addr,addr_t data)589 static int __poke_user_compat(struct task_struct *child,
590 addr_t addr, addr_t data)
591 {
592 struct compat_user *dummy32 = NULL;
593 __u32 tmp = (__u32) data;
594 addr_t offset;
595
596 if (addr < (addr_t) &dummy32->regs.acrs) {
597 /*
598 * psw, gprs, acrs and orig_gpr2 are stored on the stack
599 */
600 if (addr == (addr_t) &dummy32->regs.psw.mask) {
601 /* Build a 64 bit psw mask from 31 bit mask. */
602 if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
603 /* Invalid psw mask. */
604 return -EINVAL;
605 task_pt_regs(child)->psw.mask =
606 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
607 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
608 /* Build a 64 bit psw address from 31 bit address. */
609 task_pt_regs(child)->psw.addr =
610 (__u64) tmp & PSW32_ADDR_INSN;
611 } else {
612 /* gpr 0-15 */
613 *(__u32*)((addr_t) &task_pt_regs(child)->psw
614 + addr*2 + 4) = tmp;
615 }
616 } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
617 /*
618 * access registers are stored in the thread structure
619 */
620 offset = addr - (addr_t) &dummy32->regs.acrs;
621 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
622
623 } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
624 /*
625 * orig_gpr2 is stored on the kernel stack
626 */
627 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
628
629 } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
630 /*
631 * prevent writess of padding hole between
632 * orig_gpr2 and fp_regs on s390.
633 */
634 return 0;
635
636 } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
637 /*
638 * floating point regs. are stored in the thread structure
639 */
640 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
641 (tmp & ~FPC_VALID_MASK) != 0)
642 /* Invalid floating point control. */
643 return -EINVAL;
644 offset = addr - (addr_t) &dummy32->regs.fp_regs;
645 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
646
647 } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
648 /*
649 * Handle access to the per_info structure.
650 */
651 addr -= (addr_t) &dummy32->regs.per_info;
652 __poke_user_per_compat(child, addr, data);
653 }
654
655 return 0;
656 }
657
poke_user_compat(struct task_struct * child,addr_t addr,addr_t data)658 static int poke_user_compat(struct task_struct *child,
659 addr_t addr, addr_t data)
660 {
661 if (!is_compat_task() || (addr & 3) ||
662 addr > sizeof(struct compat_user) - 3)
663 return -EIO;
664
665 return __poke_user_compat(child, addr, data);
666 }
667
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)668 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
669 compat_ulong_t caddr, compat_ulong_t cdata)
670 {
671 unsigned long addr = caddr;
672 unsigned long data = cdata;
673 compat_ptrace_area parea;
674 int copied, ret;
675
676 switch (request) {
677 case PTRACE_PEEKUSR:
678 /* read the word at location addr in the USER area. */
679 return peek_user_compat(child, addr, data);
680
681 case PTRACE_POKEUSR:
682 /* write the word at location addr in the USER area */
683 return poke_user_compat(child, addr, data);
684
685 case PTRACE_PEEKUSR_AREA:
686 case PTRACE_POKEUSR_AREA:
687 if (copy_from_user(&parea, (void __force __user *) addr,
688 sizeof(parea)))
689 return -EFAULT;
690 addr = parea.kernel_addr;
691 data = parea.process_addr;
692 copied = 0;
693 while (copied < parea.len) {
694 if (request == PTRACE_PEEKUSR_AREA)
695 ret = peek_user_compat(child, addr, data);
696 else {
697 __u32 utmp;
698 if (get_user(utmp,
699 (__u32 __force __user *) data))
700 return -EFAULT;
701 ret = poke_user_compat(child, addr, utmp);
702 }
703 if (ret)
704 return ret;
705 addr += sizeof(unsigned int);
706 data += sizeof(unsigned int);
707 copied += sizeof(unsigned int);
708 }
709 return 0;
710 case PTRACE_GET_LAST_BREAK:
711 put_user(task_thread_info(child)->last_break,
712 (unsigned int __user *) data);
713 return 0;
714 }
715 return compat_ptrace_request(child, request, addr, data);
716 }
717 #endif
718
do_syscall_trace_enter(struct pt_regs * regs)719 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
720 {
721 long ret = 0;
722
723 /* Do the secure computing check first. */
724 secure_computing(regs->gprs[2]);
725
726 /*
727 * The sysc_tracesys code in entry.S stored the system
728 * call number to gprs[2].
729 */
730 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
731 (tracehook_report_syscall_entry(regs) ||
732 regs->gprs[2] >= NR_syscalls)) {
733 /*
734 * Tracing decided this syscall should not happen or the
735 * debugger stored an invalid system call number. Skip
736 * the system call and the system call restart handling.
737 */
738 regs->svcnr = 0;
739 ret = -1;
740 }
741
742 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
743 trace_sys_enter(regs, regs->gprs[2]);
744
745 if (unlikely(current->audit_context))
746 audit_syscall_entry(is_compat_task() ?
747 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
748 regs->gprs[2], regs->orig_gpr2,
749 regs->gprs[3], regs->gprs[4],
750 regs->gprs[5]);
751 return ret ?: regs->gprs[2];
752 }
753
do_syscall_trace_exit(struct pt_regs * regs)754 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
755 {
756 if (unlikely(current->audit_context))
757 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
758 regs->gprs[2]);
759
760 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
761 trace_sys_exit(regs, regs->gprs[2]);
762
763 if (test_thread_flag(TIF_SYSCALL_TRACE))
764 tracehook_report_syscall_exit(regs, 0);
765 }
766
767 /*
768 * user_regset definitions.
769 */
770
s390_regs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)771 static int s390_regs_get(struct task_struct *target,
772 const struct user_regset *regset,
773 unsigned int pos, unsigned int count,
774 void *kbuf, void __user *ubuf)
775 {
776 if (target == current)
777 save_access_regs(target->thread.acrs);
778
779 if (kbuf) {
780 unsigned long *k = kbuf;
781 while (count > 0) {
782 *k++ = __peek_user(target, pos);
783 count -= sizeof(*k);
784 pos += sizeof(*k);
785 }
786 } else {
787 unsigned long __user *u = ubuf;
788 while (count > 0) {
789 if (__put_user(__peek_user(target, pos), u++))
790 return -EFAULT;
791 count -= sizeof(*u);
792 pos += sizeof(*u);
793 }
794 }
795 return 0;
796 }
797
s390_regs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)798 static int s390_regs_set(struct task_struct *target,
799 const struct user_regset *regset,
800 unsigned int pos, unsigned int count,
801 const void *kbuf, const void __user *ubuf)
802 {
803 int rc = 0;
804
805 if (target == current)
806 save_access_regs(target->thread.acrs);
807
808 if (kbuf) {
809 const unsigned long *k = kbuf;
810 while (count > 0 && !rc) {
811 rc = __poke_user(target, pos, *k++);
812 count -= sizeof(*k);
813 pos += sizeof(*k);
814 }
815 } else {
816 const unsigned long __user *u = ubuf;
817 while (count > 0 && !rc) {
818 unsigned long word;
819 rc = __get_user(word, u++);
820 if (rc)
821 break;
822 rc = __poke_user(target, pos, word);
823 count -= sizeof(*u);
824 pos += sizeof(*u);
825 }
826 }
827
828 if (rc == 0 && target == current)
829 restore_access_regs(target->thread.acrs);
830
831 return rc;
832 }
833
s390_fpregs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)834 static int s390_fpregs_get(struct task_struct *target,
835 const struct user_regset *regset, unsigned int pos,
836 unsigned int count, void *kbuf, void __user *ubuf)
837 {
838 if (target == current)
839 save_fp_regs(&target->thread.fp_regs);
840
841 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
842 &target->thread.fp_regs, 0, -1);
843 }
844
s390_fpregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)845 static int s390_fpregs_set(struct task_struct *target,
846 const struct user_regset *regset, unsigned int pos,
847 unsigned int count, const void *kbuf,
848 const void __user *ubuf)
849 {
850 int rc = 0;
851
852 if (target == current)
853 save_fp_regs(&target->thread.fp_regs);
854
855 /* If setting FPC, must validate it first. */
856 if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
857 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
858 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
859 0, offsetof(s390_fp_regs, fprs));
860 if (rc)
861 return rc;
862 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
863 return -EINVAL;
864 target->thread.fp_regs.fpc = fpc[0];
865 }
866
867 if (rc == 0 && count > 0)
868 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
869 target->thread.fp_regs.fprs,
870 offsetof(s390_fp_regs, fprs), -1);
871
872 if (rc == 0 && target == current)
873 restore_fp_regs(&target->thread.fp_regs);
874
875 return rc;
876 }
877
878 #ifdef CONFIG_64BIT
879
s390_last_break_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)880 static int s390_last_break_get(struct task_struct *target,
881 const struct user_regset *regset,
882 unsigned int pos, unsigned int count,
883 void *kbuf, void __user *ubuf)
884 {
885 if (count > 0) {
886 if (kbuf) {
887 unsigned long *k = kbuf;
888 *k = task_thread_info(target)->last_break;
889 } else {
890 unsigned long __user *u = ubuf;
891 if (__put_user(task_thread_info(target)->last_break, u))
892 return -EFAULT;
893 }
894 }
895 return 0;
896 }
897
898 #endif
899
900 static const struct user_regset s390_regsets[] = {
901 [REGSET_GENERAL] = {
902 .core_note_type = NT_PRSTATUS,
903 .n = sizeof(s390_regs) / sizeof(long),
904 .size = sizeof(long),
905 .align = sizeof(long),
906 .get = s390_regs_get,
907 .set = s390_regs_set,
908 },
909 [REGSET_FP] = {
910 .core_note_type = NT_PRFPREG,
911 .n = sizeof(s390_fp_regs) / sizeof(long),
912 .size = sizeof(long),
913 .align = sizeof(long),
914 .get = s390_fpregs_get,
915 .set = s390_fpregs_set,
916 },
917 #ifdef CONFIG_64BIT
918 [REGSET_LAST_BREAK] = {
919 .core_note_type = NT_S390_LAST_BREAK,
920 .n = 1,
921 .size = sizeof(long),
922 .align = sizeof(long),
923 .get = s390_last_break_get,
924 },
925 #endif
926 };
927
928 static const struct user_regset_view user_s390_view = {
929 .name = UTS_MACHINE,
930 .e_machine = EM_S390,
931 .regsets = s390_regsets,
932 .n = ARRAY_SIZE(s390_regsets)
933 };
934
935 #ifdef CONFIG_COMPAT
s390_compat_regs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)936 static int s390_compat_regs_get(struct task_struct *target,
937 const struct user_regset *regset,
938 unsigned int pos, unsigned int count,
939 void *kbuf, void __user *ubuf)
940 {
941 if (target == current)
942 save_access_regs(target->thread.acrs);
943
944 if (kbuf) {
945 compat_ulong_t *k = kbuf;
946 while (count > 0) {
947 *k++ = __peek_user_compat(target, pos);
948 count -= sizeof(*k);
949 pos += sizeof(*k);
950 }
951 } else {
952 compat_ulong_t __user *u = ubuf;
953 while (count > 0) {
954 if (__put_user(__peek_user_compat(target, pos), u++))
955 return -EFAULT;
956 count -= sizeof(*u);
957 pos += sizeof(*u);
958 }
959 }
960 return 0;
961 }
962
s390_compat_regs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)963 static int s390_compat_regs_set(struct task_struct *target,
964 const struct user_regset *regset,
965 unsigned int pos, unsigned int count,
966 const void *kbuf, const void __user *ubuf)
967 {
968 int rc = 0;
969
970 if (target == current)
971 save_access_regs(target->thread.acrs);
972
973 if (kbuf) {
974 const compat_ulong_t *k = kbuf;
975 while (count > 0 && !rc) {
976 rc = __poke_user_compat(target, pos, *k++);
977 count -= sizeof(*k);
978 pos += sizeof(*k);
979 }
980 } else {
981 const compat_ulong_t __user *u = ubuf;
982 while (count > 0 && !rc) {
983 compat_ulong_t word;
984 rc = __get_user(word, u++);
985 if (rc)
986 break;
987 rc = __poke_user_compat(target, pos, word);
988 count -= sizeof(*u);
989 pos += sizeof(*u);
990 }
991 }
992
993 if (rc == 0 && target == current)
994 restore_access_regs(target->thread.acrs);
995
996 return rc;
997 }
998
s390_compat_regs_high_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)999 static int s390_compat_regs_high_get(struct task_struct *target,
1000 const struct user_regset *regset,
1001 unsigned int pos, unsigned int count,
1002 void *kbuf, void __user *ubuf)
1003 {
1004 compat_ulong_t *gprs_high;
1005
1006 gprs_high = (compat_ulong_t *)
1007 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1008 if (kbuf) {
1009 compat_ulong_t *k = kbuf;
1010 while (count > 0) {
1011 *k++ = *gprs_high;
1012 gprs_high += 2;
1013 count -= sizeof(*k);
1014 }
1015 } else {
1016 compat_ulong_t __user *u = ubuf;
1017 while (count > 0) {
1018 if (__put_user(*gprs_high, u++))
1019 return -EFAULT;
1020 gprs_high += 2;
1021 count -= sizeof(*u);
1022 }
1023 }
1024 return 0;
1025 }
1026
s390_compat_regs_high_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)1027 static int s390_compat_regs_high_set(struct task_struct *target,
1028 const struct user_regset *regset,
1029 unsigned int pos, unsigned int count,
1030 const void *kbuf, const void __user *ubuf)
1031 {
1032 compat_ulong_t *gprs_high;
1033 int rc = 0;
1034
1035 gprs_high = (compat_ulong_t *)
1036 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1037 if (kbuf) {
1038 const compat_ulong_t *k = kbuf;
1039 while (count > 0) {
1040 *gprs_high = *k++;
1041 *gprs_high += 2;
1042 count -= sizeof(*k);
1043 }
1044 } else {
1045 const compat_ulong_t __user *u = ubuf;
1046 while (count > 0 && !rc) {
1047 unsigned long word;
1048 rc = __get_user(word, u++);
1049 if (rc)
1050 break;
1051 *gprs_high = word;
1052 *gprs_high += 2;
1053 count -= sizeof(*u);
1054 }
1055 }
1056
1057 return rc;
1058 }
1059
s390_compat_last_break_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)1060 static int s390_compat_last_break_get(struct task_struct *target,
1061 const struct user_regset *regset,
1062 unsigned int pos, unsigned int count,
1063 void *kbuf, void __user *ubuf)
1064 {
1065 compat_ulong_t last_break;
1066
1067 if (count > 0) {
1068 last_break = task_thread_info(target)->last_break;
1069 if (kbuf) {
1070 unsigned long *k = kbuf;
1071 *k = last_break;
1072 } else {
1073 unsigned long __user *u = ubuf;
1074 if (__put_user(last_break, u))
1075 return -EFAULT;
1076 }
1077 }
1078 return 0;
1079 }
1080
1081 static const struct user_regset s390_compat_regsets[] = {
1082 [REGSET_GENERAL] = {
1083 .core_note_type = NT_PRSTATUS,
1084 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1085 .size = sizeof(compat_long_t),
1086 .align = sizeof(compat_long_t),
1087 .get = s390_compat_regs_get,
1088 .set = s390_compat_regs_set,
1089 },
1090 [REGSET_FP] = {
1091 .core_note_type = NT_PRFPREG,
1092 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1093 .size = sizeof(compat_long_t),
1094 .align = sizeof(compat_long_t),
1095 .get = s390_fpregs_get,
1096 .set = s390_fpregs_set,
1097 },
1098 [REGSET_LAST_BREAK] = {
1099 .core_note_type = NT_S390_LAST_BREAK,
1100 .n = 1,
1101 .size = sizeof(long),
1102 .align = sizeof(long),
1103 .get = s390_compat_last_break_get,
1104 },
1105 [REGSET_GENERAL_EXTENDED] = {
1106 .core_note_type = NT_S390_HIGH_GPRS,
1107 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1108 .size = sizeof(compat_long_t),
1109 .align = sizeof(compat_long_t),
1110 .get = s390_compat_regs_high_get,
1111 .set = s390_compat_regs_high_set,
1112 },
1113 };
1114
1115 static const struct user_regset_view user_s390_compat_view = {
1116 .name = "s390",
1117 .e_machine = EM_S390,
1118 .regsets = s390_compat_regsets,
1119 .n = ARRAY_SIZE(s390_compat_regsets)
1120 };
1121 #endif
1122
task_user_regset_view(struct task_struct * task)1123 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1124 {
1125 #ifdef CONFIG_COMPAT
1126 if (test_tsk_thread_flag(task, TIF_31BIT))
1127 return &user_s390_compat_view;
1128 #endif
1129 return &user_s390_view;
1130 }
1131
1132 static const char *gpr_names[NUM_GPRS] = {
1133 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
1134 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1135 };
1136
regs_get_register(struct pt_regs * regs,unsigned int offset)1137 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1138 {
1139 if (offset >= NUM_GPRS)
1140 return 0;
1141 return regs->gprs[offset];
1142 }
1143
regs_query_register_offset(const char * name)1144 int regs_query_register_offset(const char *name)
1145 {
1146 unsigned long offset;
1147
1148 if (!name || *name != 'r')
1149 return -EINVAL;
1150 if (strict_strtoul(name + 1, 10, &offset))
1151 return -EINVAL;
1152 if (offset >= NUM_GPRS)
1153 return -EINVAL;
1154 return offset;
1155 }
1156
regs_query_register_name(unsigned int offset)1157 const char *regs_query_register_name(unsigned int offset)
1158 {
1159 if (offset >= NUM_GPRS)
1160 return NULL;
1161 return gpr_names[offset];
1162 }
1163
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)1164 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1165 {
1166 unsigned long ksp = kernel_stack_pointer(regs);
1167
1168 return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1169 }
1170
1171 /**
1172 * regs_get_kernel_stack_nth() - get Nth entry of the stack
1173 * @regs:pt_regs which contains kernel stack pointer.
1174 * @n:stack entry number.
1175 *
1176 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1177 * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1178 * this returns 0.
1179 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)1180 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1181 {
1182 unsigned long addr;
1183
1184 addr = kernel_stack_pointer(regs) + n * sizeof(long);
1185 if (!regs_within_kernel_stack(regs, addr))
1186 return 0;
1187 return *(unsigned long *)addr;
1188 }
1189