[S390] ptrace: fix return value of do_syscall_trace_enter()
[linux-2.6.git] / arch / s390 / kernel / ptrace.c
1 /*
2  *  arch/s390/kernel/ptrace.c
3  *
4  *  S390 version
5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  *
9  *  Based on PowerPC version 
10  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
11  *
12  *  Derived from "arch/m68k/kernel/ptrace.c"
13  *  Copyright (C) 1994 by Hamish Macdonald
14  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
15  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
16  *
17  * Modified by Cort Dougan (cort@cs.nmt.edu) 
18  *
19  *
20  * This file is subject to the terms and conditions of the GNU General
21  * Public License.  See the file README.legal in the main directory of
22  * this archive for more details.
23  */
24
25 #include <linux/kernel.h>
26 #include <linux/sched.h>
27 #include <linux/mm.h>
28 #include <linux/smp.h>
29 #include <linux/errno.h>
30 #include <linux/ptrace.h>
31 #include <linux/user.h>
32 #include <linux/security.h>
33 #include <linux/audit.h>
34 #include <linux/signal.h>
35 #include <linux/elf.h>
36 #include <linux/regset.h>
37 #include <linux/tracehook.h>
38 #include <linux/seccomp.h>
39 #include <trace/syscall.h>
40 #include <asm/compat.h>
41 #include <asm/segment.h>
42 #include <asm/page.h>
43 #include <asm/pgtable.h>
44 #include <asm/pgalloc.h>
45 #include <asm/system.h>
46 #include <asm/uaccess.h>
47 #include <asm/unistd.h>
48 #include "entry.h"
49
50 #ifdef CONFIG_COMPAT
51 #include "compat_ptrace.h"
52 #endif
53
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/syscalls.h>
56
57 enum s390_regset {
58         REGSET_GENERAL,
59         REGSET_FP,
60         REGSET_GENERAL_EXTENDED,
61 };
62
63 static void
64 FixPerRegisters(struct task_struct *task)
65 {
66         struct pt_regs *regs;
67         per_struct *per_info;
68         per_cr_words cr_words;
69
70         regs = task_pt_regs(task);
71         per_info = (per_struct *) &task->thread.per_info;
72         per_info->control_regs.bits.em_instruction_fetch =
73                 per_info->single_step | per_info->instruction_fetch;
74         
75         if (per_info->single_step) {
76                 per_info->control_regs.bits.starting_addr = 0;
77 #ifdef CONFIG_COMPAT
78                 if (is_compat_task())
79                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
80                 else
81 #endif
82                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
83         } else {
84                 per_info->control_regs.bits.starting_addr =
85                         per_info->starting_addr;
86                 per_info->control_regs.bits.ending_addr =
87                         per_info->ending_addr;
88         }
89         /*
90          * if any of the control reg tracing bits are on 
91          * we switch on per in the psw
92          */
93         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
94                 regs->psw.mask |= PSW_MASK_PER;
95         else
96                 regs->psw.mask &= ~PSW_MASK_PER;
97
98         if (per_info->control_regs.bits.em_storage_alteration)
99                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
100         else
101                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
102
103         if (task == current) {
104                 __ctl_store(cr_words, 9, 11);
105                 if (memcmp(&cr_words, &per_info->control_regs.words,
106                            sizeof(cr_words)) != 0)
107                         __ctl_load(per_info->control_regs.words, 9, 11);
108         }
109 }
110
111 void user_enable_single_step(struct task_struct *task)
112 {
113         task->thread.per_info.single_step = 1;
114         FixPerRegisters(task);
115 }
116
117 void user_disable_single_step(struct task_struct *task)
118 {
119         task->thread.per_info.single_step = 0;
120         FixPerRegisters(task);
121 }
122
123 /*
124  * Called by kernel/ptrace.c when detaching..
125  *
126  * Make sure single step bits etc are not set.
127  */
128 void
129 ptrace_disable(struct task_struct *child)
130 {
131         /* make sure the single step bit is not set. */
132         user_disable_single_step(child);
133 }
134
135 #ifndef CONFIG_64BIT
136 # define __ADDR_MASK 3
137 #else
138 # define __ADDR_MASK 7
139 #endif
140
141 /*
142  * Read the word at offset addr from the user area of a process. The
143  * trouble here is that the information is littered over different
144  * locations. The process registers are found on the kernel stack,
145  * the floating point stuff and the trace settings are stored in
146  * the task structure. In addition the different structures in
147  * struct user contain pad bytes that should be read as zeroes.
148  * Lovely...
149  */
150 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
151 {
152         struct user *dummy = NULL;
153         addr_t offset, tmp;
154
155         if (addr < (addr_t) &dummy->regs.acrs) {
156                 /*
157                  * psw and gprs are stored on the stack
158                  */
159                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
160                 if (addr == (addr_t) &dummy->regs.psw.mask)
161                         /* Remove per bit from user psw. */
162                         tmp &= ~PSW_MASK_PER;
163
164         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
165                 /*
166                  * access registers are stored in the thread structure
167                  */
168                 offset = addr - (addr_t) &dummy->regs.acrs;
169 #ifdef CONFIG_64BIT
170                 /*
171                  * Very special case: old & broken 64 bit gdb reading
172                  * from acrs[15]. Result is a 64 bit value. Read the
173                  * 32 bit acrs[15] value and shift it by 32. Sick...
174                  */
175                 if (addr == (addr_t) &dummy->regs.acrs[15])
176                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
177                 else
178 #endif
179                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
180
181         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
182                 /*
183                  * orig_gpr2 is stored on the kernel stack
184                  */
185                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
186
187         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
188                 /*
189                  * prevent reads of padding hole between
190                  * orig_gpr2 and fp_regs on s390.
191                  */
192                 tmp = 0;
193
194         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
195                 /* 
196                  * floating point regs. are stored in the thread structure
197                  */
198                 offset = addr - (addr_t) &dummy->regs.fp_regs;
199                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
200                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
201                         tmp &= (unsigned long) FPC_VALID_MASK
202                                 << (BITS_PER_LONG - 32);
203
204         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
205                 /*
206                  * per_info is found in the thread structure
207                  */
208                 offset = addr - (addr_t) &dummy->regs.per_info;
209                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
210
211         } else
212                 tmp = 0;
213
214         return tmp;
215 }
216
217 static int
218 peek_user(struct task_struct *child, addr_t addr, addr_t data)
219 {
220         addr_t tmp, mask;
221
222         /*
223          * Stupid gdb peeks/pokes the access registers in 64 bit with
224          * an alignment of 4. Programmers from hell...
225          */
226         mask = __ADDR_MASK;
227 #ifdef CONFIG_64BIT
228         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
229             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
230                 mask = 3;
231 #endif
232         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
233                 return -EIO;
234
235         tmp = __peek_user(child, addr);
236         return put_user(tmp, (addr_t __user *) data);
237 }
238
239 /*
240  * Write a word to the user area of a process at location addr. This
241  * operation does have an additional problem compared to peek_user.
242  * Stores to the program status word and on the floating point
243  * control register needs to get checked for validity.
244  */
245 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
246 {
247         struct user *dummy = NULL;
248         addr_t offset;
249
250         if (addr < (addr_t) &dummy->regs.acrs) {
251                 /*
252                  * psw and gprs are stored on the stack
253                  */
254                 if (addr == (addr_t) &dummy->regs.psw.mask &&
255 #ifdef CONFIG_COMPAT
256                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
257 #endif
258                     data != PSW_MASK_MERGE(psw_user_bits, data))
259                         /* Invalid psw mask. */
260                         return -EINVAL;
261 #ifndef CONFIG_64BIT
262                 if (addr == (addr_t) &dummy->regs.psw.addr)
263                         /* I'd like to reject addresses without the
264                            high order bit but older gdb's rely on it */
265                         data |= PSW_ADDR_AMODE;
266 #endif
267                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
268
269         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
270                 /*
271                  * access registers are stored in the thread structure
272                  */
273                 offset = addr - (addr_t) &dummy->regs.acrs;
274 #ifdef CONFIG_64BIT
275                 /*
276                  * Very special case: old & broken 64 bit gdb writing
277                  * to acrs[15] with a 64 bit value. Ignore the lower
278                  * half of the value and write the upper 32 bit to
279                  * acrs[15]. Sick...
280                  */
281                 if (addr == (addr_t) &dummy->regs.acrs[15])
282                         child->thread.acrs[15] = (unsigned int) (data >> 32);
283                 else
284 #endif
285                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
286
287         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
288                 /*
289                  * orig_gpr2 is stored on the kernel stack
290                  */
291                 task_pt_regs(child)->orig_gpr2 = data;
292
293         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
294                 /*
295                  * prevent writes of padding hole between
296                  * orig_gpr2 and fp_regs on s390.
297                  */
298                 return 0;
299
300         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
301                 /*
302                  * floating point regs. are stored in the thread structure
303                  */
304                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
305                     (data & ~((unsigned long) FPC_VALID_MASK
306                               << (BITS_PER_LONG - 32))) != 0)
307                         return -EINVAL;
308                 offset = addr - (addr_t) &dummy->regs.fp_regs;
309                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
310
311         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
312                 /*
313                  * per_info is found in the thread structure 
314                  */
315                 offset = addr - (addr_t) &dummy->regs.per_info;
316                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
317
318         }
319
320         FixPerRegisters(child);
321         return 0;
322 }
323
324 static int
325 poke_user(struct task_struct *child, addr_t addr, addr_t data)
326 {
327         addr_t mask;
328
329         /*
330          * Stupid gdb peeks/pokes the access registers in 64 bit with
331          * an alignment of 4. Programmers from hell indeed...
332          */
333         mask = __ADDR_MASK;
334 #ifdef CONFIG_64BIT
335         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
336             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
337                 mask = 3;
338 #endif
339         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
340                 return -EIO;
341
342         return __poke_user(child, addr, data);
343 }
344
345 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
346 {
347         ptrace_area parea; 
348         int copied, ret;
349
350         switch (request) {
351         case PTRACE_PEEKUSR:
352                 /* read the word at location addr in the USER area. */
353                 return peek_user(child, addr, data);
354
355         case PTRACE_POKEUSR:
356                 /* write the word at location addr in the USER area */
357                 return poke_user(child, addr, data);
358
359         case PTRACE_PEEKUSR_AREA:
360         case PTRACE_POKEUSR_AREA:
361                 if (copy_from_user(&parea, (void __force __user *) addr,
362                                                         sizeof(parea)))
363                         return -EFAULT;
364                 addr = parea.kernel_addr;
365                 data = parea.process_addr;
366                 copied = 0;
367                 while (copied < parea.len) {
368                         if (request == PTRACE_PEEKUSR_AREA)
369                                 ret = peek_user(child, addr, data);
370                         else {
371                                 addr_t utmp;
372                                 if (get_user(utmp,
373                                              (addr_t __force __user *) data))
374                                         return -EFAULT;
375                                 ret = poke_user(child, addr, utmp);
376                         }
377                         if (ret)
378                                 return ret;
379                         addr += sizeof(unsigned long);
380                         data += sizeof(unsigned long);
381                         copied += sizeof(unsigned long);
382                 }
383                 return 0;
384         default:
385                 /* Removing high order bit from addr (only for 31 bit). */
386                 addr &= PSW_ADDR_INSN;
387                 return ptrace_request(child, request, addr, data);
388         }
389 }
390
391 #ifdef CONFIG_COMPAT
392 /*
393  * Now the fun part starts... a 31 bit program running in the
394  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
395  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
396  * to handle, the difference to the 64 bit versions of the requests
397  * is that the access is done in multiples of 4 byte instead of
398  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
399  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
400  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
401  * is a 31 bit program too, the content of struct user can be
402  * emulated. A 31 bit program peeking into the struct user of
403  * a 64 bit program is a no-no.
404  */
405
406 /*
407  * Same as peek_user but for a 31 bit program.
408  */
409 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
410 {
411         struct user32 *dummy32 = NULL;
412         per_struct32 *dummy_per32 = NULL;
413         addr_t offset;
414         __u32 tmp;
415
416         if (addr < (addr_t) &dummy32->regs.acrs) {
417                 /*
418                  * psw and gprs are stored on the stack
419                  */
420                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
421                         /* Fake a 31 bit psw mask. */
422                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
423                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
424                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
425                         /* Fake a 31 bit psw address. */
426                         tmp = (__u32) task_pt_regs(child)->psw.addr |
427                                 PSW32_ADDR_AMODE31;
428                 } else {
429                         /* gpr 0-15 */
430                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
431                                          addr*2 + 4);
432                 }
433         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
434                 /*
435                  * access registers are stored in the thread structure
436                  */
437                 offset = addr - (addr_t) &dummy32->regs.acrs;
438                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
439
440         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
441                 /*
442                  * orig_gpr2 is stored on the kernel stack
443                  */
444                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
445
446         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
447                 /*
448                  * prevent reads of padding hole between
449                  * orig_gpr2 and fp_regs on s390.
450                  */
451                 tmp = 0;
452
453         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
454                 /*
455                  * floating point regs. are stored in the thread structure 
456                  */
457                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
458                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
459
460         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
461                 /*
462                  * per_info is found in the thread structure
463                  */
464                 offset = addr - (addr_t) &dummy32->regs.per_info;
465                 /* This is magic. See per_struct and per_struct32. */
466                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
467                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
468                     (offset >= (addr_t) &dummy_per32->starting_addr &&
469                      offset <= (addr_t) &dummy_per32->ending_addr) ||
470                     offset == (addr_t) &dummy_per32->lowcore.words.address)
471                         offset = offset*2 + 4;
472                 else
473                         offset = offset*2;
474                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
475
476         } else
477                 tmp = 0;
478
479         return tmp;
480 }
481
482 static int peek_user_compat(struct task_struct *child,
483                             addr_t addr, addr_t data)
484 {
485         __u32 tmp;
486
487         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
488                 return -EIO;
489
490         tmp = __peek_user_compat(child, addr);
491         return put_user(tmp, (__u32 __user *) data);
492 }
493
494 /*
495  * Same as poke_user but for a 31 bit program.
496  */
497 static int __poke_user_compat(struct task_struct *child,
498                               addr_t addr, addr_t data)
499 {
500         struct user32 *dummy32 = NULL;
501         per_struct32 *dummy_per32 = NULL;
502         __u32 tmp = (__u32) data;
503         addr_t offset;
504
505         if (addr < (addr_t) &dummy32->regs.acrs) {
506                 /*
507                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
508                  */
509                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
510                         /* Build a 64 bit psw mask from 31 bit mask. */
511                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
512                                 /* Invalid psw mask. */
513                                 return -EINVAL;
514                         task_pt_regs(child)->psw.mask =
515                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
516                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
517                         /* Build a 64 bit psw address from 31 bit address. */
518                         task_pt_regs(child)->psw.addr =
519                                 (__u64) tmp & PSW32_ADDR_INSN;
520                 } else {
521                         /* gpr 0-15 */
522                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
523                                   + addr*2 + 4) = tmp;
524                 }
525         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
526                 /*
527                  * access registers are stored in the thread structure
528                  */
529                 offset = addr - (addr_t) &dummy32->regs.acrs;
530                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
531
532         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
533                 /*
534                  * orig_gpr2 is stored on the kernel stack
535                  */
536                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
537
538         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
539                 /*
540                  * prevent writess of padding hole between
541                  * orig_gpr2 and fp_regs on s390.
542                  */
543                 return 0;
544
545         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
546                 /*
547                  * floating point regs. are stored in the thread structure 
548                  */
549                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
550                     (tmp & ~FPC_VALID_MASK) != 0)
551                         /* Invalid floating point control. */
552                         return -EINVAL;
553                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
554                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
555
556         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
557                 /*
558                  * per_info is found in the thread structure.
559                  */
560                 offset = addr - (addr_t) &dummy32->regs.per_info;
561                 /*
562                  * This is magic. See per_struct and per_struct32.
563                  * By incident the offsets in per_struct are exactly
564                  * twice the offsets in per_struct32 for all fields.
565                  * The 8 byte fields need special handling though,
566                  * because the second half (bytes 4-7) is needed and
567                  * not the first half.
568                  */
569                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
570                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
571                     (offset >= (addr_t) &dummy_per32->starting_addr &&
572                      offset <= (addr_t) &dummy_per32->ending_addr) ||
573                     offset == (addr_t) &dummy_per32->lowcore.words.address)
574                         offset = offset*2 + 4;
575                 else
576                         offset = offset*2;
577                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
578
579         }
580
581         FixPerRegisters(child);
582         return 0;
583 }
584
585 static int poke_user_compat(struct task_struct *child,
586                             addr_t addr, addr_t data)
587 {
588         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
589                 return -EIO;
590
591         return __poke_user_compat(child, addr, data);
592 }
593
594 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
595                         compat_ulong_t caddr, compat_ulong_t cdata)
596 {
597         unsigned long addr = caddr;
598         unsigned long data = cdata;
599         ptrace_area_emu31 parea; 
600         int copied, ret;
601
602         switch (request) {
603         case PTRACE_PEEKUSR:
604                 /* read the word at location addr in the USER area. */
605                 return peek_user_compat(child, addr, data);
606
607         case PTRACE_POKEUSR:
608                 /* write the word at location addr in the USER area */
609                 return poke_user_compat(child, addr, data);
610
611         case PTRACE_PEEKUSR_AREA:
612         case PTRACE_POKEUSR_AREA:
613                 if (copy_from_user(&parea, (void __force __user *) addr,
614                                                         sizeof(parea)))
615                         return -EFAULT;
616                 addr = parea.kernel_addr;
617                 data = parea.process_addr;
618                 copied = 0;
619                 while (copied < parea.len) {
620                         if (request == PTRACE_PEEKUSR_AREA)
621                                 ret = peek_user_compat(child, addr, data);
622                         else {
623                                 __u32 utmp;
624                                 if (get_user(utmp,
625                                              (__u32 __force __user *) data))
626                                         return -EFAULT;
627                                 ret = poke_user_compat(child, addr, utmp);
628                         }
629                         if (ret)
630                                 return ret;
631                         addr += sizeof(unsigned int);
632                         data += sizeof(unsigned int);
633                         copied += sizeof(unsigned int);
634                 }
635                 return 0;
636         }
637         return compat_ptrace_request(child, request, addr, data);
638 }
639 #endif
640
641 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
642 {
643         long ret = 0;
644
645         /* Do the secure computing check first. */
646         secure_computing(regs->gprs[2]);
647
648         /*
649          * The sysc_tracesys code in entry.S stored the system
650          * call number to gprs[2].
651          */
652         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
653             (tracehook_report_syscall_entry(regs) ||
654              regs->gprs[2] >= NR_syscalls)) {
655                 /*
656                  * Tracing decided this syscall should not happen or the
657                  * debugger stored an invalid system call number. Skip
658                  * the system call and the system call restart handling.
659                  */
660                 regs->svcnr = 0;
661                 ret = -1;
662         }
663
664         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
665                 trace_sys_enter(regs, regs->gprs[2]);
666
667         if (unlikely(current->audit_context))
668                 audit_syscall_entry(is_compat_task() ?
669                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
670                                     regs->gprs[2], regs->orig_gpr2,
671                                     regs->gprs[3], regs->gprs[4],
672                                     regs->gprs[5]);
673         return ret ?: regs->gprs[2];
674 }
675
676 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
677 {
678         if (unlikely(current->audit_context))
679                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
680                                    regs->gprs[2]);
681
682         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
683                 trace_sys_exit(regs, regs->gprs[2]);
684
685         if (test_thread_flag(TIF_SYSCALL_TRACE))
686                 tracehook_report_syscall_exit(regs, 0);
687 }
688
689 /*
690  * user_regset definitions.
691  */
692
693 static int s390_regs_get(struct task_struct *target,
694                          const struct user_regset *regset,
695                          unsigned int pos, unsigned int count,
696                          void *kbuf, void __user *ubuf)
697 {
698         if (target == current)
699                 save_access_regs(target->thread.acrs);
700
701         if (kbuf) {
702                 unsigned long *k = kbuf;
703                 while (count > 0) {
704                         *k++ = __peek_user(target, pos);
705                         count -= sizeof(*k);
706                         pos += sizeof(*k);
707                 }
708         } else {
709                 unsigned long __user *u = ubuf;
710                 while (count > 0) {
711                         if (__put_user(__peek_user(target, pos), u++))
712                                 return -EFAULT;
713                         count -= sizeof(*u);
714                         pos += sizeof(*u);
715                 }
716         }
717         return 0;
718 }
719
720 static int s390_regs_set(struct task_struct *target,
721                          const struct user_regset *regset,
722                          unsigned int pos, unsigned int count,
723                          const void *kbuf, const void __user *ubuf)
724 {
725         int rc = 0;
726
727         if (target == current)
728                 save_access_regs(target->thread.acrs);
729
730         if (kbuf) {
731                 const unsigned long *k = kbuf;
732                 while (count > 0 && !rc) {
733                         rc = __poke_user(target, pos, *k++);
734                         count -= sizeof(*k);
735                         pos += sizeof(*k);
736                 }
737         } else {
738                 const unsigned long  __user *u = ubuf;
739                 while (count > 0 && !rc) {
740                         unsigned long word;
741                         rc = __get_user(word, u++);
742                         if (rc)
743                                 break;
744                         rc = __poke_user(target, pos, word);
745                         count -= sizeof(*u);
746                         pos += sizeof(*u);
747                 }
748         }
749
750         if (rc == 0 && target == current)
751                 restore_access_regs(target->thread.acrs);
752
753         return rc;
754 }
755
756 static int s390_fpregs_get(struct task_struct *target,
757                            const struct user_regset *regset, unsigned int pos,
758                            unsigned int count, void *kbuf, void __user *ubuf)
759 {
760         if (target == current)
761                 save_fp_regs(&target->thread.fp_regs);
762
763         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
764                                    &target->thread.fp_regs, 0, -1);
765 }
766
767 static int s390_fpregs_set(struct task_struct *target,
768                            const struct user_regset *regset, unsigned int pos,
769                            unsigned int count, const void *kbuf,
770                            const void __user *ubuf)
771 {
772         int rc = 0;
773
774         if (target == current)
775                 save_fp_regs(&target->thread.fp_regs);
776
777         /* If setting FPC, must validate it first. */
778         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
779                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
780                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
781                                         0, offsetof(s390_fp_regs, fprs));
782                 if (rc)
783                         return rc;
784                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
785                         return -EINVAL;
786                 target->thread.fp_regs.fpc = fpc[0];
787         }
788
789         if (rc == 0 && count > 0)
790                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
791                                         target->thread.fp_regs.fprs,
792                                         offsetof(s390_fp_regs, fprs), -1);
793
794         if (rc == 0 && target == current)
795                 restore_fp_regs(&target->thread.fp_regs);
796
797         return rc;
798 }
799
800 static const struct user_regset s390_regsets[] = {
801         [REGSET_GENERAL] = {
802                 .core_note_type = NT_PRSTATUS,
803                 .n = sizeof(s390_regs) / sizeof(long),
804                 .size = sizeof(long),
805                 .align = sizeof(long),
806                 .get = s390_regs_get,
807                 .set = s390_regs_set,
808         },
809         [REGSET_FP] = {
810                 .core_note_type = NT_PRFPREG,
811                 .n = sizeof(s390_fp_regs) / sizeof(long),
812                 .size = sizeof(long),
813                 .align = sizeof(long),
814                 .get = s390_fpregs_get,
815                 .set = s390_fpregs_set,
816         },
817 };
818
819 static const struct user_regset_view user_s390_view = {
820         .name = UTS_MACHINE,
821         .e_machine = EM_S390,
822         .regsets = s390_regsets,
823         .n = ARRAY_SIZE(s390_regsets)
824 };
825
826 #ifdef CONFIG_COMPAT
827 static int s390_compat_regs_get(struct task_struct *target,
828                                 const struct user_regset *regset,
829                                 unsigned int pos, unsigned int count,
830                                 void *kbuf, void __user *ubuf)
831 {
832         if (target == current)
833                 save_access_regs(target->thread.acrs);
834
835         if (kbuf) {
836                 compat_ulong_t *k = kbuf;
837                 while (count > 0) {
838                         *k++ = __peek_user_compat(target, pos);
839                         count -= sizeof(*k);
840                         pos += sizeof(*k);
841                 }
842         } else {
843                 compat_ulong_t __user *u = ubuf;
844                 while (count > 0) {
845                         if (__put_user(__peek_user_compat(target, pos), u++))
846                                 return -EFAULT;
847                         count -= sizeof(*u);
848                         pos += sizeof(*u);
849                 }
850         }
851         return 0;
852 }
853
854 static int s390_compat_regs_set(struct task_struct *target,
855                                 const struct user_regset *regset,
856                                 unsigned int pos, unsigned int count,
857                                 const void *kbuf, const void __user *ubuf)
858 {
859         int rc = 0;
860
861         if (target == current)
862                 save_access_regs(target->thread.acrs);
863
864         if (kbuf) {
865                 const compat_ulong_t *k = kbuf;
866                 while (count > 0 && !rc) {
867                         rc = __poke_user_compat(target, pos, *k++);
868                         count -= sizeof(*k);
869                         pos += sizeof(*k);
870                 }
871         } else {
872                 const compat_ulong_t  __user *u = ubuf;
873                 while (count > 0 && !rc) {
874                         compat_ulong_t word;
875                         rc = __get_user(word, u++);
876                         if (rc)
877                                 break;
878                         rc = __poke_user_compat(target, pos, word);
879                         count -= sizeof(*u);
880                         pos += sizeof(*u);
881                 }
882         }
883
884         if (rc == 0 && target == current)
885                 restore_access_regs(target->thread.acrs);
886
887         return rc;
888 }
889
890 static int s390_compat_regs_high_get(struct task_struct *target,
891                                      const struct user_regset *regset,
892                                      unsigned int pos, unsigned int count,
893                                      void *kbuf, void __user *ubuf)
894 {
895         compat_ulong_t *gprs_high;
896
897         gprs_high = (compat_ulong_t *)
898                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
899         if (kbuf) {
900                 compat_ulong_t *k = kbuf;
901                 while (count > 0) {
902                         *k++ = *gprs_high;
903                         gprs_high += 2;
904                         count -= sizeof(*k);
905                 }
906         } else {
907                 compat_ulong_t __user *u = ubuf;
908                 while (count > 0) {
909                         if (__put_user(*gprs_high, u++))
910                                 return -EFAULT;
911                         gprs_high += 2;
912                         count -= sizeof(*u);
913                 }
914         }
915         return 0;
916 }
917
918 static int s390_compat_regs_high_set(struct task_struct *target,
919                                      const struct user_regset *regset,
920                                      unsigned int pos, unsigned int count,
921                                      const void *kbuf, const void __user *ubuf)
922 {
923         compat_ulong_t *gprs_high;
924         int rc = 0;
925
926         gprs_high = (compat_ulong_t *)
927                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
928         if (kbuf) {
929                 const compat_ulong_t *k = kbuf;
930                 while (count > 0) {
931                         *gprs_high = *k++;
932                         *gprs_high += 2;
933                         count -= sizeof(*k);
934                 }
935         } else {
936                 const compat_ulong_t  __user *u = ubuf;
937                 while (count > 0 && !rc) {
938                         unsigned long word;
939                         rc = __get_user(word, u++);
940                         if (rc)
941                                 break;
942                         *gprs_high = word;
943                         *gprs_high += 2;
944                         count -= sizeof(*u);
945                 }
946         }
947
948         return rc;
949 }
950
951 static const struct user_regset s390_compat_regsets[] = {
952         [REGSET_GENERAL] = {
953                 .core_note_type = NT_PRSTATUS,
954                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
955                 .size = sizeof(compat_long_t),
956                 .align = sizeof(compat_long_t),
957                 .get = s390_compat_regs_get,
958                 .set = s390_compat_regs_set,
959         },
960         [REGSET_FP] = {
961                 .core_note_type = NT_PRFPREG,
962                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
963                 .size = sizeof(compat_long_t),
964                 .align = sizeof(compat_long_t),
965                 .get = s390_fpregs_get,
966                 .set = s390_fpregs_set,
967         },
968         [REGSET_GENERAL_EXTENDED] = {
969                 .core_note_type = NT_S390_HIGH_GPRS,
970                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
971                 .size = sizeof(compat_long_t),
972                 .align = sizeof(compat_long_t),
973                 .get = s390_compat_regs_high_get,
974                 .set = s390_compat_regs_high_set,
975         },
976 };
977
978 static const struct user_regset_view user_s390_compat_view = {
979         .name = "s390",
980         .e_machine = EM_S390,
981         .regsets = s390_compat_regsets,
982         .n = ARRAY_SIZE(s390_compat_regsets)
983 };
984 #endif
985
986 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
987 {
988 #ifdef CONFIG_COMPAT
989         if (test_tsk_thread_flag(task, TIF_31BIT))
990                 return &user_s390_compat_view;
991 #endif
992         return &user_s390_view;
993 }
994
995 static const char *gpr_names[NUM_GPRS] = {
996         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
997         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
998 };
999
1000 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1001 {
1002         if (offset >= NUM_GPRS)
1003                 return 0;
1004         return regs->gprs[offset];
1005 }
1006
1007 int regs_query_register_offset(const char *name)
1008 {
1009         unsigned long offset;
1010
1011         if (!name || *name != 'r')
1012                 return -EINVAL;
1013         if (strict_strtoul(name + 1, 10, &offset))
1014                 return -EINVAL;
1015         if (offset >= NUM_GPRS)
1016                 return -EINVAL;
1017         return offset;
1018 }
1019
1020 const char *regs_query_register_name(unsigned int offset)
1021 {
1022         if (offset >= NUM_GPRS)
1023                 return NULL;
1024         return gpr_names[offset];
1025 }
1026
1027 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1028 {
1029         unsigned long ksp = kernel_stack_pointer(regs);
1030
1031         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1032 }
1033
1034 /**
1035  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1036  * @regs:pt_regs which contains kernel stack pointer.
1037  * @n:stack entry number.
1038  *
1039  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1040  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1041  * this returns 0.
1042  */
1043 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1044 {
1045         unsigned long addr;
1046
1047         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1048         if (!regs_within_kernel_stack(regs, addr))
1049                 return 0;
1050         return *(unsigned long *)addr;
1051 }