9d82ed4bcb273a91bd6c4875d204218da2d420a2
[linux-2.6.git] / arch / s390 / kernel / ptrace.c
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_SYSTEM_CALL,
46         REGSET_GENERAL_EXTENDED,
47 };
48
49 void update_per_regs(struct task_struct *task)
50 {
51         struct pt_regs *regs = task_pt_regs(task);
52         struct thread_struct *thread = &task->thread;
53         struct per_regs old, new;
54
55         /* Copy user specified PER registers */
56         new.control = thread->per_user.control;
57         new.start = thread->per_user.start;
58         new.end = thread->per_user.end;
59
60         /* merge TIF_SINGLE_STEP into user specified PER registers. */
61         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
62                 new.control |= PER_EVENT_IFETCH;
63                 new.start = 0;
64                 new.end = PSW_ADDR_INSN;
65         }
66
67         /* Take care of the PER enablement bit in the PSW. */
68         if (!(new.control & PER_EVENT_MASK)) {
69                 regs->psw.mask &= ~PSW_MASK_PER;
70                 return;
71         }
72         regs->psw.mask |= PSW_MASK_PER;
73         __ctl_store(old, 9, 11);
74         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
75                 __ctl_load(new, 9, 11);
76 }
77
78 void user_enable_single_step(struct task_struct *task)
79 {
80         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
81         if (task == current)
82                 update_per_regs(task);
83 }
84
85 void user_disable_single_step(struct task_struct *task)
86 {
87         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
88         if (task == current)
89                 update_per_regs(task);
90 }
91
92 /*
93  * Called by kernel/ptrace.c when detaching..
94  *
95  * Clear all debugging related fields.
96  */
97 void ptrace_disable(struct task_struct *task)
98 {
99         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
100         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
101         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
102         clear_tsk_thread_flag(task, TIF_PER_TRAP);
103 }
104
105 #ifndef CONFIG_64BIT
106 # define __ADDR_MASK 3
107 #else
108 # define __ADDR_MASK 7
109 #endif
110
111 static inline unsigned long __peek_user_per(struct task_struct *child,
112                                             addr_t addr)
113 {
114         struct per_struct_kernel *dummy = NULL;
115
116         if (addr == (addr_t) &dummy->cr9)
117                 /* Control bits of the active per set. */
118                 return test_thread_flag(TIF_SINGLE_STEP) ?
119                         PER_EVENT_IFETCH : child->thread.per_user.control;
120         else if (addr == (addr_t) &dummy->cr10)
121                 /* Start address of the active per set. */
122                 return test_thread_flag(TIF_SINGLE_STEP) ?
123                         0 : child->thread.per_user.start;
124         else if (addr == (addr_t) &dummy->cr11)
125                 /* End address of the active per set. */
126                 return test_thread_flag(TIF_SINGLE_STEP) ?
127                         PSW_ADDR_INSN : child->thread.per_user.end;
128         else if (addr == (addr_t) &dummy->bits)
129                 /* Single-step bit. */
130                 return test_thread_flag(TIF_SINGLE_STEP) ?
131                         (1UL << (BITS_PER_LONG - 1)) : 0;
132         else if (addr == (addr_t) &dummy->starting_addr)
133                 /* Start address of the user specified per set. */
134                 return child->thread.per_user.start;
135         else if (addr == (addr_t) &dummy->ending_addr)
136                 /* End address of the user specified per set. */
137                 return child->thread.per_user.end;
138         else if (addr == (addr_t) &dummy->perc_atmid)
139                 /* PER code, ATMID and AI of the last PER trap */
140                 return (unsigned long)
141                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
142         else if (addr == (addr_t) &dummy->address)
143                 /* Address of the last PER trap */
144                 return child->thread.per_event.address;
145         else if (addr == (addr_t) &dummy->access_id)
146                 /* Access id of the last PER trap */
147                 return (unsigned long)
148                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
149         return 0;
150 }
151
152 /*
153  * Read the word at offset addr from the user area of a process. The
154  * trouble here is that the information is littered over different
155  * locations. The process registers are found on the kernel stack,
156  * the floating point stuff and the trace settings are stored in
157  * the task structure. In addition the different structures in
158  * struct user contain pad bytes that should be read as zeroes.
159  * Lovely...
160  */
161 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
162 {
163         struct user *dummy = NULL;
164         addr_t offset, tmp;
165
166         if (addr < (addr_t) &dummy->regs.acrs) {
167                 /*
168                  * psw and gprs are stored on the stack
169                  */
170                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
171                 if (addr == (addr_t) &dummy->regs.psw.mask)
172                         /* Return a clean psw mask. */
173                         tmp = psw_user_bits | (tmp & PSW_MASK_USER);
174
175         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
176                 /*
177                  * access registers are stored in the thread structure
178                  */
179                 offset = addr - (addr_t) &dummy->regs.acrs;
180 #ifdef CONFIG_64BIT
181                 /*
182                  * Very special case: old & broken 64 bit gdb reading
183                  * from acrs[15]. Result is a 64 bit value. Read the
184                  * 32 bit acrs[15] value and shift it by 32. Sick...
185                  */
186                 if (addr == (addr_t) &dummy->regs.acrs[15])
187                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
188                 else
189 #endif
190                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
191
192         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
193                 /*
194                  * orig_gpr2 is stored on the kernel stack
195                  */
196                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
197
198         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
199                 /*
200                  * prevent reads of padding hole between
201                  * orig_gpr2 and fp_regs on s390.
202                  */
203                 tmp = 0;
204
205         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
206                 /* 
207                  * floating point regs. are stored in the thread structure
208                  */
209                 offset = addr - (addr_t) &dummy->regs.fp_regs;
210                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
211                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
212                         tmp &= (unsigned long) FPC_VALID_MASK
213                                 << (BITS_PER_LONG - 32);
214
215         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
216                 /*
217                  * Handle access to the per_info structure.
218                  */
219                 addr -= (addr_t) &dummy->regs.per_info;
220                 tmp = __peek_user_per(child, addr);
221
222         } else
223                 tmp = 0;
224
225         return tmp;
226 }
227
228 static int
229 peek_user(struct task_struct *child, addr_t addr, addr_t data)
230 {
231         addr_t tmp, mask;
232
233         /*
234          * Stupid gdb peeks/pokes the access registers in 64 bit with
235          * an alignment of 4. Programmers from hell...
236          */
237         mask = __ADDR_MASK;
238 #ifdef CONFIG_64BIT
239         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
240             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
241                 mask = 3;
242 #endif
243         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
244                 return -EIO;
245
246         tmp = __peek_user(child, addr);
247         return put_user(tmp, (addr_t __user *) data);
248 }
249
250 static inline void __poke_user_per(struct task_struct *child,
251                                    addr_t addr, addr_t data)
252 {
253         struct per_struct_kernel *dummy = NULL;
254
255         /*
256          * There are only three fields in the per_info struct that the
257          * debugger user can write to.
258          * 1) cr9: the debugger wants to set a new PER event mask
259          * 2) starting_addr: the debugger wants to set a new starting
260          *    address to use with the PER event mask.
261          * 3) ending_addr: the debugger wants to set a new ending
262          *    address to use with the PER event mask.
263          * The user specified PER event mask and the start and end
264          * addresses are used only if single stepping is not in effect.
265          * Writes to any other field in per_info are ignored.
266          */
267         if (addr == (addr_t) &dummy->cr9)
268                 /* PER event mask of the user specified per set. */
269                 child->thread.per_user.control =
270                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
271         else if (addr == (addr_t) &dummy->starting_addr)
272                 /* Starting address of the user specified per set. */
273                 child->thread.per_user.start = data;
274         else if (addr == (addr_t) &dummy->ending_addr)
275                 /* Ending address of the user specified per set. */
276                 child->thread.per_user.end = data;
277 }
278
279 /*
280  * Write a word to the user area of a process at location addr. This
281  * operation does have an additional problem compared to peek_user.
282  * Stores to the program status word and on the floating point
283  * control register needs to get checked for validity.
284  */
285 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
286 {
287         struct user *dummy = NULL;
288         addr_t offset;
289
290         if (addr < (addr_t) &dummy->regs.acrs) {
291                 /*
292                  * psw and gprs are stored on the stack
293                  */
294                 if (addr == (addr_t) &dummy->regs.psw.mask &&
295                     ((data & ~PSW_MASK_USER) != psw_user_bits ||
296                      ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))))
297                         /* Invalid psw mask. */
298                         return -EINVAL;
299                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
300
301         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
302                 /*
303                  * access registers are stored in the thread structure
304                  */
305                 offset = addr - (addr_t) &dummy->regs.acrs;
306 #ifdef CONFIG_64BIT
307                 /*
308                  * Very special case: old & broken 64 bit gdb writing
309                  * to acrs[15] with a 64 bit value. Ignore the lower
310                  * half of the value and write the upper 32 bit to
311                  * acrs[15]. Sick...
312                  */
313                 if (addr == (addr_t) &dummy->regs.acrs[15])
314                         child->thread.acrs[15] = (unsigned int) (data >> 32);
315                 else
316 #endif
317                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
318
319         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
320                 /*
321                  * orig_gpr2 is stored on the kernel stack
322                  */
323                 task_pt_regs(child)->orig_gpr2 = data;
324
325         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
326                 /*
327                  * prevent writes of padding hole between
328                  * orig_gpr2 and fp_regs on s390.
329                  */
330                 return 0;
331
332         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
333                 /*
334                  * floating point regs. are stored in the thread structure
335                  */
336                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
337                     (data & ~((unsigned long) FPC_VALID_MASK
338                               << (BITS_PER_LONG - 32))) != 0)
339                         return -EINVAL;
340                 offset = addr - (addr_t) &dummy->regs.fp_regs;
341                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
342
343         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
344                 /*
345                  * Handle access to the per_info structure.
346                  */
347                 addr -= (addr_t) &dummy->regs.per_info;
348                 __poke_user_per(child, addr, data);
349
350         }
351
352         return 0;
353 }
354
355 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
356 {
357         addr_t mask;
358
359         /*
360          * Stupid gdb peeks/pokes the access registers in 64 bit with
361          * an alignment of 4. Programmers from hell indeed...
362          */
363         mask = __ADDR_MASK;
364 #ifdef CONFIG_64BIT
365         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
366             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
367                 mask = 3;
368 #endif
369         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
370                 return -EIO;
371
372         return __poke_user(child, addr, data);
373 }
374
375 long arch_ptrace(struct task_struct *child, long request,
376                  unsigned long addr, unsigned long data)
377 {
378         ptrace_area parea; 
379         int copied, ret;
380
381         switch (request) {
382         case PTRACE_PEEKUSR:
383                 /* read the word at location addr in the USER area. */
384                 return peek_user(child, addr, data);
385
386         case PTRACE_POKEUSR:
387                 /* write the word at location addr in the USER area */
388                 return poke_user(child, addr, data);
389
390         case PTRACE_PEEKUSR_AREA:
391         case PTRACE_POKEUSR_AREA:
392                 if (copy_from_user(&parea, (void __force __user *) addr,
393                                                         sizeof(parea)))
394                         return -EFAULT;
395                 addr = parea.kernel_addr;
396                 data = parea.process_addr;
397                 copied = 0;
398                 while (copied < parea.len) {
399                         if (request == PTRACE_PEEKUSR_AREA)
400                                 ret = peek_user(child, addr, data);
401                         else {
402                                 addr_t utmp;
403                                 if (get_user(utmp,
404                                              (addr_t __force __user *) data))
405                                         return -EFAULT;
406                                 ret = poke_user(child, addr, utmp);
407                         }
408                         if (ret)
409                                 return ret;
410                         addr += sizeof(unsigned long);
411                         data += sizeof(unsigned long);
412                         copied += sizeof(unsigned long);
413                 }
414                 return 0;
415         case PTRACE_GET_LAST_BREAK:
416                 put_user(task_thread_info(child)->last_break,
417                          (unsigned long __user *) data);
418                 return 0;
419         default:
420                 /* Removing high order bit from addr (only for 31 bit). */
421                 addr &= PSW_ADDR_INSN;
422                 return ptrace_request(child, request, addr, data);
423         }
424 }
425
426 #ifdef CONFIG_COMPAT
427 /*
428  * Now the fun part starts... a 31 bit program running in the
429  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
430  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
431  * to handle, the difference to the 64 bit versions of the requests
432  * is that the access is done in multiples of 4 byte instead of
433  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
434  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
435  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
436  * is a 31 bit program too, the content of struct user can be
437  * emulated. A 31 bit program peeking into the struct user of
438  * a 64 bit program is a no-no.
439  */
440
441 /*
442  * Same as peek_user_per but for a 31 bit program.
443  */
444 static inline __u32 __peek_user_per_compat(struct task_struct *child,
445                                            addr_t addr)
446 {
447         struct compat_per_struct_kernel *dummy32 = NULL;
448
449         if (addr == (addr_t) &dummy32->cr9)
450                 /* Control bits of the active per set. */
451                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
452                         PER_EVENT_IFETCH : child->thread.per_user.control;
453         else if (addr == (addr_t) &dummy32->cr10)
454                 /* Start address of the active per set. */
455                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
456                         0 : child->thread.per_user.start;
457         else if (addr == (addr_t) &dummy32->cr11)
458                 /* End address of the active per set. */
459                 return test_thread_flag(TIF_SINGLE_STEP) ?
460                         PSW32_ADDR_INSN : child->thread.per_user.end;
461         else if (addr == (addr_t) &dummy32->bits)
462                 /* Single-step bit. */
463                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
464                         0x80000000 : 0;
465         else if (addr == (addr_t) &dummy32->starting_addr)
466                 /* Start address of the user specified per set. */
467                 return (__u32) child->thread.per_user.start;
468         else if (addr == (addr_t) &dummy32->ending_addr)
469                 /* End address of the user specified per set. */
470                 return (__u32) child->thread.per_user.end;
471         else if (addr == (addr_t) &dummy32->perc_atmid)
472                 /* PER code, ATMID and AI of the last PER trap */
473                 return (__u32) child->thread.per_event.cause << 16;
474         else if (addr == (addr_t) &dummy32->address)
475                 /* Address of the last PER trap */
476                 return (__u32) child->thread.per_event.address;
477         else if (addr == (addr_t) &dummy32->access_id)
478                 /* Access id of the last PER trap */
479                 return (__u32) child->thread.per_event.paid << 24;
480         return 0;
481 }
482
483 /*
484  * Same as peek_user but for a 31 bit program.
485  */
486 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
487 {
488         struct compat_user *dummy32 = NULL;
489         addr_t offset;
490         __u32 tmp;
491
492         if (addr < (addr_t) &dummy32->regs.acrs) {
493                 struct pt_regs *regs = task_pt_regs(child);
494                 /*
495                  * psw and gprs are stored on the stack
496                  */
497                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
498                         /* Fake a 31 bit psw mask. */
499                         tmp = (__u32)(regs->psw.mask >> 32);
500                         tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
501                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
502                         /* Fake a 31 bit psw address. */
503                         tmp = (__u32) regs->psw.addr |
504                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
505                 } else {
506                         /* gpr 0-15 */
507                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
508                 }
509         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
510                 /*
511                  * access registers are stored in the thread structure
512                  */
513                 offset = addr - (addr_t) &dummy32->regs.acrs;
514                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
515
516         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
517                 /*
518                  * orig_gpr2 is stored on the kernel stack
519                  */
520                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
521
522         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
523                 /*
524                  * prevent reads of padding hole between
525                  * orig_gpr2 and fp_regs on s390.
526                  */
527                 tmp = 0;
528
529         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
530                 /*
531                  * floating point regs. are stored in the thread structure 
532                  */
533                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
534                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
535
536         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
537                 /*
538                  * Handle access to the per_info structure.
539                  */
540                 addr -= (addr_t) &dummy32->regs.per_info;
541                 tmp = __peek_user_per_compat(child, addr);
542
543         } else
544                 tmp = 0;
545
546         return tmp;
547 }
548
549 static int peek_user_compat(struct task_struct *child,
550                             addr_t addr, addr_t data)
551 {
552         __u32 tmp;
553
554         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
555                 return -EIO;
556
557         tmp = __peek_user_compat(child, addr);
558         return put_user(tmp, (__u32 __user *) data);
559 }
560
561 /*
562  * Same as poke_user_per but for a 31 bit program.
563  */
564 static inline void __poke_user_per_compat(struct task_struct *child,
565                                           addr_t addr, __u32 data)
566 {
567         struct compat_per_struct_kernel *dummy32 = NULL;
568
569         if (addr == (addr_t) &dummy32->cr9)
570                 /* PER event mask of the user specified per set. */
571                 child->thread.per_user.control =
572                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
573         else if (addr == (addr_t) &dummy32->starting_addr)
574                 /* Starting address of the user specified per set. */
575                 child->thread.per_user.start = data;
576         else if (addr == (addr_t) &dummy32->ending_addr)
577                 /* Ending address of the user specified per set. */
578                 child->thread.per_user.end = data;
579 }
580
581 /*
582  * Same as poke_user but for a 31 bit program.
583  */
584 static int __poke_user_compat(struct task_struct *child,
585                               addr_t addr, addr_t data)
586 {
587         struct compat_user *dummy32 = NULL;
588         __u32 tmp = (__u32) data;
589         addr_t offset;
590
591         if (addr < (addr_t) &dummy32->regs.acrs) {
592                 struct pt_regs *regs = task_pt_regs(child);
593                 /*
594                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
595                  */
596                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
597                         /* Build a 64 bit psw mask from 31 bit mask. */
598                         if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
599                                 /* Invalid psw mask. */
600                                 return -EINVAL;
601                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
602                                 (regs->psw.mask & PSW_MASK_BA) |
603                                 (__u64)(tmp & PSW32_MASK_USER) << 32;
604                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
605                         /* Build a 64 bit psw address from 31 bit address. */
606                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
607                         /* Transfer 31 bit amode bit to psw mask. */
608                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
609                                 (__u64)(tmp & PSW32_ADDR_AMODE);
610                 } else {
611                         /* gpr 0-15 */
612                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
613                 }
614         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
615                 /*
616                  * access registers are stored in the thread structure
617                  */
618                 offset = addr - (addr_t) &dummy32->regs.acrs;
619                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
620
621         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
622                 /*
623                  * orig_gpr2 is stored on the kernel stack
624                  */
625                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
626
627         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
628                 /*
629                  * prevent writess of padding hole between
630                  * orig_gpr2 and fp_regs on s390.
631                  */
632                 return 0;
633
634         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
635                 /*
636                  * floating point regs. are stored in the thread structure 
637                  */
638                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
639                     (tmp & ~FPC_VALID_MASK) != 0)
640                         /* Invalid floating point control. */
641                         return -EINVAL;
642                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
643                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
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                 __poke_user_per_compat(child, addr, data);
651         }
652
653         return 0;
654 }
655
656 static int poke_user_compat(struct task_struct *child,
657                             addr_t addr, addr_t data)
658 {
659         if (!is_compat_task() || (addr & 3) ||
660             addr > sizeof(struct compat_user) - 3)
661                 return -EIO;
662
663         return __poke_user_compat(child, addr, data);
664 }
665
666 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
667                         compat_ulong_t caddr, compat_ulong_t cdata)
668 {
669         unsigned long addr = caddr;
670         unsigned long data = cdata;
671         compat_ptrace_area parea;
672         int copied, ret;
673
674         switch (request) {
675         case PTRACE_PEEKUSR:
676                 /* read the word at location addr in the USER area. */
677                 return peek_user_compat(child, addr, data);
678
679         case PTRACE_POKEUSR:
680                 /* write the word at location addr in the USER area */
681                 return poke_user_compat(child, addr, data);
682
683         case PTRACE_PEEKUSR_AREA:
684         case PTRACE_POKEUSR_AREA:
685                 if (copy_from_user(&parea, (void __force __user *) addr,
686                                                         sizeof(parea)))
687                         return -EFAULT;
688                 addr = parea.kernel_addr;
689                 data = parea.process_addr;
690                 copied = 0;
691                 while (copied < parea.len) {
692                         if (request == PTRACE_PEEKUSR_AREA)
693                                 ret = peek_user_compat(child, addr, data);
694                         else {
695                                 __u32 utmp;
696                                 if (get_user(utmp,
697                                              (__u32 __force __user *) data))
698                                         return -EFAULT;
699                                 ret = poke_user_compat(child, addr, utmp);
700                         }
701                         if (ret)
702                                 return ret;
703                         addr += sizeof(unsigned int);
704                         data += sizeof(unsigned int);
705                         copied += sizeof(unsigned int);
706                 }
707                 return 0;
708         case PTRACE_GET_LAST_BREAK:
709                 put_user(task_thread_info(child)->last_break,
710                          (unsigned int __user *) data);
711                 return 0;
712         }
713         return compat_ptrace_request(child, request, addr, data);
714 }
715 #endif
716
717 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
718 {
719         long ret = 0;
720
721         /* Do the secure computing check first. */
722         secure_computing(regs->gprs[2]);
723
724         /*
725          * The sysc_tracesys code in entry.S stored the system
726          * call number to gprs[2].
727          */
728         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
729             (tracehook_report_syscall_entry(regs) ||
730              regs->gprs[2] >= NR_syscalls)) {
731                 /*
732                  * Tracing decided this syscall should not happen or the
733                  * debugger stored an invalid system call number. Skip
734                  * the system call and the system call restart handling.
735                  */
736                 clear_thread_flag(TIF_SYSCALL);
737                 ret = -1;
738         }
739
740         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
741                 trace_sys_enter(regs, regs->gprs[2]);
742
743         audit_syscall_entry(is_compat_task() ?
744                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
745                             regs->gprs[2], regs->orig_gpr2,
746                             regs->gprs[3], regs->gprs[4],
747                             regs->gprs[5]);
748         return ret ?: regs->gprs[2];
749 }
750
751 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
752 {
753         audit_syscall_exit(regs);
754
755         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
756                 trace_sys_exit(regs, regs->gprs[2]);
757
758         if (test_thread_flag(TIF_SYSCALL_TRACE))
759                 tracehook_report_syscall_exit(regs, 0);
760 }
761
762 /*
763  * user_regset definitions.
764  */
765
766 static int s390_regs_get(struct task_struct *target,
767                          const struct user_regset *regset,
768                          unsigned int pos, unsigned int count,
769                          void *kbuf, void __user *ubuf)
770 {
771         if (target == current)
772                 save_access_regs(target->thread.acrs);
773
774         if (kbuf) {
775                 unsigned long *k = kbuf;
776                 while (count > 0) {
777                         *k++ = __peek_user(target, pos);
778                         count -= sizeof(*k);
779                         pos += sizeof(*k);
780                 }
781         } else {
782                 unsigned long __user *u = ubuf;
783                 while (count > 0) {
784                         if (__put_user(__peek_user(target, pos), u++))
785                                 return -EFAULT;
786                         count -= sizeof(*u);
787                         pos += sizeof(*u);
788                 }
789         }
790         return 0;
791 }
792
793 static int s390_regs_set(struct task_struct *target,
794                          const struct user_regset *regset,
795                          unsigned int pos, unsigned int count,
796                          const void *kbuf, const void __user *ubuf)
797 {
798         int rc = 0;
799
800         if (target == current)
801                 save_access_regs(target->thread.acrs);
802
803         if (kbuf) {
804                 const unsigned long *k = kbuf;
805                 while (count > 0 && !rc) {
806                         rc = __poke_user(target, pos, *k++);
807                         count -= sizeof(*k);
808                         pos += sizeof(*k);
809                 }
810         } else {
811                 const unsigned long  __user *u = ubuf;
812                 while (count > 0 && !rc) {
813                         unsigned long word;
814                         rc = __get_user(word, u++);
815                         if (rc)
816                                 break;
817                         rc = __poke_user(target, pos, word);
818                         count -= sizeof(*u);
819                         pos += sizeof(*u);
820                 }
821         }
822
823         if (rc == 0 && target == current)
824                 restore_access_regs(target->thread.acrs);
825
826         return rc;
827 }
828
829 static int s390_fpregs_get(struct task_struct *target,
830                            const struct user_regset *regset, unsigned int pos,
831                            unsigned int count, void *kbuf, void __user *ubuf)
832 {
833         if (target == current)
834                 save_fp_regs(&target->thread.fp_regs);
835
836         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
837                                    &target->thread.fp_regs, 0, -1);
838 }
839
840 static int s390_fpregs_set(struct task_struct *target,
841                            const struct user_regset *regset, unsigned int pos,
842                            unsigned int count, const void *kbuf,
843                            const void __user *ubuf)
844 {
845         int rc = 0;
846
847         if (target == current)
848                 save_fp_regs(&target->thread.fp_regs);
849
850         /* If setting FPC, must validate it first. */
851         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
852                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
853                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
854                                         0, offsetof(s390_fp_regs, fprs));
855                 if (rc)
856                         return rc;
857                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
858                         return -EINVAL;
859                 target->thread.fp_regs.fpc = fpc[0];
860         }
861
862         if (rc == 0 && count > 0)
863                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
864                                         target->thread.fp_regs.fprs,
865                                         offsetof(s390_fp_regs, fprs), -1);
866
867         if (rc == 0 && target == current)
868                 restore_fp_regs(&target->thread.fp_regs);
869
870         return rc;
871 }
872
873 #ifdef CONFIG_64BIT
874
875 static int s390_last_break_get(struct task_struct *target,
876                                const struct user_regset *regset,
877                                unsigned int pos, unsigned int count,
878                                void *kbuf, void __user *ubuf)
879 {
880         if (count > 0) {
881                 if (kbuf) {
882                         unsigned long *k = kbuf;
883                         *k = task_thread_info(target)->last_break;
884                 } else {
885                         unsigned long  __user *u = ubuf;
886                         if (__put_user(task_thread_info(target)->last_break, u))
887                                 return -EFAULT;
888                 }
889         }
890         return 0;
891 }
892
893 static int s390_last_break_set(struct task_struct *target,
894                                const struct user_regset *regset,
895                                unsigned int pos, unsigned int count,
896                                const void *kbuf, const void __user *ubuf)
897 {
898         return 0;
899 }
900
901 #endif
902
903 static int s390_system_call_get(struct task_struct *target,
904                                 const struct user_regset *regset,
905                                 unsigned int pos, unsigned int count,
906                                 void *kbuf, void __user *ubuf)
907 {
908         unsigned int *data = &task_thread_info(target)->system_call;
909         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
910                                    data, 0, sizeof(unsigned int));
911 }
912
913 static int s390_system_call_set(struct task_struct *target,
914                                 const struct user_regset *regset,
915                                 unsigned int pos, unsigned int count,
916                                 const void *kbuf, const void __user *ubuf)
917 {
918         unsigned int *data = &task_thread_info(target)->system_call;
919         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
920                                   data, 0, sizeof(unsigned int));
921 }
922
923 static const struct user_regset s390_regsets[] = {
924         [REGSET_GENERAL] = {
925                 .core_note_type = NT_PRSTATUS,
926                 .n = sizeof(s390_regs) / sizeof(long),
927                 .size = sizeof(long),
928                 .align = sizeof(long),
929                 .get = s390_regs_get,
930                 .set = s390_regs_set,
931         },
932         [REGSET_FP] = {
933                 .core_note_type = NT_PRFPREG,
934                 .n = sizeof(s390_fp_regs) / sizeof(long),
935                 .size = sizeof(long),
936                 .align = sizeof(long),
937                 .get = s390_fpregs_get,
938                 .set = s390_fpregs_set,
939         },
940 #ifdef CONFIG_64BIT
941         [REGSET_LAST_BREAK] = {
942                 .core_note_type = NT_S390_LAST_BREAK,
943                 .n = 1,
944                 .size = sizeof(long),
945                 .align = sizeof(long),
946                 .get = s390_last_break_get,
947                 .set = s390_last_break_set,
948         },
949 #endif
950         [REGSET_SYSTEM_CALL] = {
951                 .core_note_type = NT_S390_SYSTEM_CALL,
952                 .n = 1,
953                 .size = sizeof(unsigned int),
954                 .align = sizeof(unsigned int),
955                 .get = s390_system_call_get,
956                 .set = s390_system_call_set,
957         },
958 };
959
960 static const struct user_regset_view user_s390_view = {
961         .name = UTS_MACHINE,
962         .e_machine = EM_S390,
963         .regsets = s390_regsets,
964         .n = ARRAY_SIZE(s390_regsets)
965 };
966
967 #ifdef CONFIG_COMPAT
968 static int s390_compat_regs_get(struct task_struct *target,
969                                 const struct user_regset *regset,
970                                 unsigned int pos, unsigned int count,
971                                 void *kbuf, void __user *ubuf)
972 {
973         if (target == current)
974                 save_access_regs(target->thread.acrs);
975
976         if (kbuf) {
977                 compat_ulong_t *k = kbuf;
978                 while (count > 0) {
979                         *k++ = __peek_user_compat(target, pos);
980                         count -= sizeof(*k);
981                         pos += sizeof(*k);
982                 }
983         } else {
984                 compat_ulong_t __user *u = ubuf;
985                 while (count > 0) {
986                         if (__put_user(__peek_user_compat(target, pos), u++))
987                                 return -EFAULT;
988                         count -= sizeof(*u);
989                         pos += sizeof(*u);
990                 }
991         }
992         return 0;
993 }
994
995 static int s390_compat_regs_set(struct task_struct *target,
996                                 const struct user_regset *regset,
997                                 unsigned int pos, unsigned int count,
998                                 const void *kbuf, const void __user *ubuf)
999 {
1000         int rc = 0;
1001
1002         if (target == current)
1003                 save_access_regs(target->thread.acrs);
1004
1005         if (kbuf) {
1006                 const compat_ulong_t *k = kbuf;
1007                 while (count > 0 && !rc) {
1008                         rc = __poke_user_compat(target, pos, *k++);
1009                         count -= sizeof(*k);
1010                         pos += sizeof(*k);
1011                 }
1012         } else {
1013                 const compat_ulong_t  __user *u = ubuf;
1014                 while (count > 0 && !rc) {
1015                         compat_ulong_t word;
1016                         rc = __get_user(word, u++);
1017                         if (rc)
1018                                 break;
1019                         rc = __poke_user_compat(target, pos, word);
1020                         count -= sizeof(*u);
1021                         pos += sizeof(*u);
1022                 }
1023         }
1024
1025         if (rc == 0 && target == current)
1026                 restore_access_regs(target->thread.acrs);
1027
1028         return rc;
1029 }
1030
1031 static int s390_compat_regs_high_get(struct task_struct *target,
1032                                      const struct user_regset *regset,
1033                                      unsigned int pos, unsigned int count,
1034                                      void *kbuf, void __user *ubuf)
1035 {
1036         compat_ulong_t *gprs_high;
1037
1038         gprs_high = (compat_ulong_t *)
1039                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1040         if (kbuf) {
1041                 compat_ulong_t *k = kbuf;
1042                 while (count > 0) {
1043                         *k++ = *gprs_high;
1044                         gprs_high += 2;
1045                         count -= sizeof(*k);
1046                 }
1047         } else {
1048                 compat_ulong_t __user *u = ubuf;
1049                 while (count > 0) {
1050                         if (__put_user(*gprs_high, u++))
1051                                 return -EFAULT;
1052                         gprs_high += 2;
1053                         count -= sizeof(*u);
1054                 }
1055         }
1056         return 0;
1057 }
1058
1059 static int s390_compat_regs_high_set(struct task_struct *target,
1060                                      const struct user_regset *regset,
1061                                      unsigned int pos, unsigned int count,
1062                                      const void *kbuf, const void __user *ubuf)
1063 {
1064         compat_ulong_t *gprs_high;
1065         int rc = 0;
1066
1067         gprs_high = (compat_ulong_t *)
1068                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1069         if (kbuf) {
1070                 const compat_ulong_t *k = kbuf;
1071                 while (count > 0) {
1072                         *gprs_high = *k++;
1073                         *gprs_high += 2;
1074                         count -= sizeof(*k);
1075                 }
1076         } else {
1077                 const compat_ulong_t  __user *u = ubuf;
1078                 while (count > 0 && !rc) {
1079                         unsigned long word;
1080                         rc = __get_user(word, u++);
1081                         if (rc)
1082                                 break;
1083                         *gprs_high = word;
1084                         *gprs_high += 2;
1085                         count -= sizeof(*u);
1086                 }
1087         }
1088
1089         return rc;
1090 }
1091
1092 static int s390_compat_last_break_get(struct task_struct *target,
1093                                       const struct user_regset *regset,
1094                                       unsigned int pos, unsigned int count,
1095                                       void *kbuf, void __user *ubuf)
1096 {
1097         compat_ulong_t last_break;
1098
1099         if (count > 0) {
1100                 last_break = task_thread_info(target)->last_break;
1101                 if (kbuf) {
1102                         unsigned long *k = kbuf;
1103                         *k = last_break;
1104                 } else {
1105                         unsigned long  __user *u = ubuf;
1106                         if (__put_user(last_break, u))
1107                                 return -EFAULT;
1108                 }
1109         }
1110         return 0;
1111 }
1112
1113 static int s390_compat_last_break_set(struct task_struct *target,
1114                                       const struct user_regset *regset,
1115                                       unsigned int pos, unsigned int count,
1116                                       const void *kbuf, const void __user *ubuf)
1117 {
1118         return 0;
1119 }
1120
1121 static const struct user_regset s390_compat_regsets[] = {
1122         [REGSET_GENERAL] = {
1123                 .core_note_type = NT_PRSTATUS,
1124                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1125                 .size = sizeof(compat_long_t),
1126                 .align = sizeof(compat_long_t),
1127                 .get = s390_compat_regs_get,
1128                 .set = s390_compat_regs_set,
1129         },
1130         [REGSET_FP] = {
1131                 .core_note_type = NT_PRFPREG,
1132                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1133                 .size = sizeof(compat_long_t),
1134                 .align = sizeof(compat_long_t),
1135                 .get = s390_fpregs_get,
1136                 .set = s390_fpregs_set,
1137         },
1138         [REGSET_LAST_BREAK] = {
1139                 .core_note_type = NT_S390_LAST_BREAK,
1140                 .n = 1,
1141                 .size = sizeof(long),
1142                 .align = sizeof(long),
1143                 .get = s390_compat_last_break_get,
1144                 .set = s390_compat_last_break_set,
1145         },
1146         [REGSET_SYSTEM_CALL] = {
1147                 .core_note_type = NT_S390_SYSTEM_CALL,
1148                 .n = 1,
1149                 .size = sizeof(compat_uint_t),
1150                 .align = sizeof(compat_uint_t),
1151                 .get = s390_system_call_get,
1152                 .set = s390_system_call_set,
1153         },
1154         [REGSET_GENERAL_EXTENDED] = {
1155                 .core_note_type = NT_S390_HIGH_GPRS,
1156                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1157                 .size = sizeof(compat_long_t),
1158                 .align = sizeof(compat_long_t),
1159                 .get = s390_compat_regs_high_get,
1160                 .set = s390_compat_regs_high_set,
1161         },
1162 };
1163
1164 static const struct user_regset_view user_s390_compat_view = {
1165         .name = "s390",
1166         .e_machine = EM_S390,
1167         .regsets = s390_compat_regsets,
1168         .n = ARRAY_SIZE(s390_compat_regsets)
1169 };
1170 #endif
1171
1172 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1173 {
1174 #ifdef CONFIG_COMPAT
1175         if (test_tsk_thread_flag(task, TIF_31BIT))
1176                 return &user_s390_compat_view;
1177 #endif
1178         return &user_s390_view;
1179 }
1180
1181 static const char *gpr_names[NUM_GPRS] = {
1182         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1183         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1184 };
1185
1186 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1187 {
1188         if (offset >= NUM_GPRS)
1189                 return 0;
1190         return regs->gprs[offset];
1191 }
1192
1193 int regs_query_register_offset(const char *name)
1194 {
1195         unsigned long offset;
1196
1197         if (!name || *name != 'r')
1198                 return -EINVAL;
1199         if (strict_strtoul(name + 1, 10, &offset))
1200                 return -EINVAL;
1201         if (offset >= NUM_GPRS)
1202                 return -EINVAL;
1203         return offset;
1204 }
1205
1206 const char *regs_query_register_name(unsigned int offset)
1207 {
1208         if (offset >= NUM_GPRS)
1209                 return NULL;
1210         return gpr_names[offset];
1211 }
1212
1213 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1214 {
1215         unsigned long ksp = kernel_stack_pointer(regs);
1216
1217         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1218 }
1219
1220 /**
1221  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1222  * @regs:pt_regs which contains kernel stack pointer.
1223  * @n:stack entry number.
1224  *
1225  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1226  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1227  * this returns 0.
1228  */
1229 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1230 {
1231         unsigned long addr;
1232
1233         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1234         if (!regs_within_kernel_stack(regs, addr))
1235                 return 0;
1236         return *(unsigned long *)addr;
1237 }