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Merge branch 'akpm'
[linux-2.6/next.git] / arch / sh / kernel / ptrace_64.c
blobc8f97649f354b5f4b80366b79a95c9a9a0f4d4bb
1 /*
2 * arch/sh/kernel/ptrace_64.c
3 *
4 * Copyright (C) 2000, 2001 Paolo Alberelli
5 * Copyright (C) 2003 - 2008 Paul Mundt
6 *
7 * Started from SH3/4 version:
8 * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
9 *
10 * Original x86 implementation:
11 * By Ross Biro 1/23/92
12 * edited by Linus Torvalds
13 *
14 * This file is subject to the terms and conditions of the GNU General Public
15 * License. See the file "COPYING" in the main directory of this archive
16 * for more details.
17 */
18 #include <linux/kernel.h>
19 #include <linux/rwsem.h>
20 #include <linux/sched.h>
21 #include <linux/mm.h>
22 #include <linux/smp.h>
23 #include <linux/bitops.h>
24 #include <linux/errno.h>
25 #include <linux/ptrace.h>
26 #include <linux/user.h>
27 #include <linux/signal.h>
28 #include <linux/syscalls.h>
29 #include <linux/audit.h>
30 #include <linux/seccomp.h>
31 #include <linux/tracehook.h>
32 #include <linux/elf.h>
33 #include <linux/regset.h>
34 #include <asm/io.h>
35 #include <asm/uaccess.h>
36 #include <asm/pgtable.h>
37 #include <asm/system.h>
38 #include <asm/processor.h>
39 #include <asm/mmu_context.h>
40 #include <asm/syscalls.h>
41 #include <asm/fpu.h>
42
43 #define CREATE_TRACE_POINTS
44 #include <trace/events/syscalls.h>
45
46 /* This mask defines the bits of the SR which the user is not allowed to
47 change, which are everything except S, Q, M, PR, SZ, FR. */
48 #define SR_MASK (0xffff8cfd)
49
50 /*
51 * does not yet catch signals sent when the child dies.
52 * in exit.c or in signal.c.
53 */
54
55 /*
56 * This routine will get a word from the user area in the process kernel stack.
57 */
58 static inline int get_stack_long(struct task_struct *task, int offset)
59 {
60 unsigned char *stack;
61
62 stack = (unsigned char *)(task->thread.uregs);
63 stack += offset;
64 return (*((int *)stack));
65 }
66
67 static inline unsigned long
68 get_fpu_long(struct task_struct *task, unsigned long addr)
69 {
70 unsigned long tmp;
71 struct pt_regs *regs;
72 regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;
73
74 if (!tsk_used_math(task)) {
75 if (addr == offsetof(struct user_fpu_struct, fpscr)) {
76 tmp = FPSCR_INIT;
77 } else {
78 tmp = 0xffffffffUL; /* matches initial value in fpu.c */
79 }
80 return tmp;
81 }
82
83 if (last_task_used_math == task) {
84 enable_fpu();
85 save_fpu(task);
86 disable_fpu();
87 last_task_used_math = 0;
88 regs->sr |= SR_FD;
89 }
90
91 tmp = ((long *)task->thread.xstate)[addr / sizeof(unsigned long)];
92 return tmp;
93 }
94
95 /*
96 * This routine will put a word into the user area in the process kernel stack.
97 */
98 static inline int put_stack_long(struct task_struct *task, int offset,
99 unsigned long data)
100 {
101 unsigned char *stack;
102
103 stack = (unsigned char *)(task->thread.uregs);
104 stack += offset;
105 *(unsigned long *) stack = data;
106 return 0;
107 }
108
109 static inline int
110 put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data)
111 {
112 struct pt_regs *regs;
113
114 regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;
115
116 if (!tsk_used_math(task)) {
117 init_fpu(task);
118 } else if (last_task_used_math == task) {
119 enable_fpu();
120 save_fpu(task);
121 disable_fpu();
122 last_task_used_math = 0;
123 regs->sr |= SR_FD;
124 }
125
126 ((long *)task->thread.xstate)[addr / sizeof(unsigned long)] = data;
127 return 0;
128 }
129
130 void user_enable_single_step(struct task_struct *child)
131 {
132 struct pt_regs *regs = child->thread.uregs;
133
134 regs->sr |= SR_SSTEP; /* auto-resetting upon exception */
135
136 set_tsk_thread_flag(child, TIF_SINGLESTEP);
137 }
138
139 void user_disable_single_step(struct task_struct *child)
140 {
141 struct pt_regs *regs = child->thread.uregs;
142
143 regs->sr &= ~SR_SSTEP;
144
145 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
146 }
147
148 static int genregs_get(struct task_struct *target,
149 const struct user_regset *regset,
150 unsigned int pos, unsigned int count,
151 void *kbuf, void __user *ubuf)
152 {
153 const struct pt_regs *regs = task_pt_regs(target);
154 int ret;
155
156 /* PC, SR, SYSCALL */
157 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
158 &regs->pc,
159 0, 3 * sizeof(unsigned long long));
160
161 /* R1 -> R63 */
162 if (!ret)
163 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
164 regs->regs,
165 offsetof(struct pt_regs, regs[0]),
166 63 * sizeof(unsigned long long));
167 /* TR0 -> TR7 */
168 if (!ret)
169 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
170 regs->tregs,
171 offsetof(struct pt_regs, tregs[0]),
172 8 * sizeof(unsigned long long));
173
174 if (!ret)
175 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
176 sizeof(struct pt_regs), -1);
177
178 return ret;
179 }
180
181 static int genregs_set(struct task_struct *target,
182 const struct user_regset *regset,
183 unsigned int pos, unsigned int count,
184 const void *kbuf, const void __user *ubuf)
185 {
186 struct pt_regs *regs = task_pt_regs(target);
187 int ret;
188
189 /* PC, SR, SYSCALL */
190 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
191 &regs->pc,
192 0, 3 * sizeof(unsigned long long));
193
194 /* R1 -> R63 */
195 if (!ret && count > 0)
196 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
197 regs->regs,
198 offsetof(struct pt_regs, regs[0]),
199 63 * sizeof(unsigned long long));
200
201 /* TR0 -> TR7 */
202 if (!ret && count > 0)
203 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
204 regs->tregs,
205 offsetof(struct pt_regs, tregs[0]),
206 8 * sizeof(unsigned long long));
207
208 if (!ret)
209 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
210 sizeof(struct pt_regs), -1);
211
212 return ret;
213 }
214
215 #ifdef CONFIG_SH_FPU
216 int fpregs_get(struct task_struct *target,
217 const struct user_regset *regset,
218 unsigned int pos, unsigned int count,
219 void *kbuf, void __user *ubuf)
220 {
221 int ret;
222
223 ret = init_fpu(target);
224 if (ret)
225 return ret;
226
227 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
228 &target->thread.xstate->hardfpu, 0, -1);
229 }
230
231 static int fpregs_set(struct task_struct *target,
232 const struct user_regset *regset,
233 unsigned int pos, unsigned int count,
234 const void *kbuf, const void __user *ubuf)
235 {
236 int ret;
237
238 ret = init_fpu(target);
239 if (ret)
240 return ret;
241
242 set_stopped_child_used_math(target);
243
244 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
245 &target->thread.xstate->hardfpu, 0, -1);
246 }
247
248 static int fpregs_active(struct task_struct *target,
249 const struct user_regset *regset)
250 {
251 return tsk_used_math(target) ? regset->n : 0;
252 }
253 #endif
254
255 const struct pt_regs_offset regoffset_table[] = {
256 REG_OFFSET_NAME(pc),
257 REG_OFFSET_NAME(sr),
258 REG_OFFSET_NAME(syscall_nr),
259 REGS_OFFSET_NAME(0),
260 REGS_OFFSET_NAME(1),
261 REGS_OFFSET_NAME(2),
262 REGS_OFFSET_NAME(3),
263 REGS_OFFSET_NAME(4),
264 REGS_OFFSET_NAME(5),
265 REGS_OFFSET_NAME(6),
266 REGS_OFFSET_NAME(7),
267 REGS_OFFSET_NAME(8),
268 REGS_OFFSET_NAME(9),
269 REGS_OFFSET_NAME(10),
270 REGS_OFFSET_NAME(11),
271 REGS_OFFSET_NAME(12),
272 REGS_OFFSET_NAME(13),
273 REGS_OFFSET_NAME(14),
274 REGS_OFFSET_NAME(15),
275 REGS_OFFSET_NAME(16),
276 REGS_OFFSET_NAME(17),
277 REGS_OFFSET_NAME(18),
278 REGS_OFFSET_NAME(19),
279 REGS_OFFSET_NAME(20),
280 REGS_OFFSET_NAME(21),
281 REGS_OFFSET_NAME(22),
282 REGS_OFFSET_NAME(23),
283 REGS_OFFSET_NAME(24),
284 REGS_OFFSET_NAME(25),
285 REGS_OFFSET_NAME(26),
286 REGS_OFFSET_NAME(27),
287 REGS_OFFSET_NAME(28),
288 REGS_OFFSET_NAME(29),
289 REGS_OFFSET_NAME(30),
290 REGS_OFFSET_NAME(31),
291 REGS_OFFSET_NAME(32),
292 REGS_OFFSET_NAME(33),
293 REGS_OFFSET_NAME(34),
294 REGS_OFFSET_NAME(35),
295 REGS_OFFSET_NAME(36),
296 REGS_OFFSET_NAME(37),
297 REGS_OFFSET_NAME(38),
298 REGS_OFFSET_NAME(39),
299 REGS_OFFSET_NAME(40),
300 REGS_OFFSET_NAME(41),
301 REGS_OFFSET_NAME(42),
302 REGS_OFFSET_NAME(43),
303 REGS_OFFSET_NAME(44),
304 REGS_OFFSET_NAME(45),
305 REGS_OFFSET_NAME(46),
306 REGS_OFFSET_NAME(47),
307 REGS_OFFSET_NAME(48),
308 REGS_OFFSET_NAME(49),
309 REGS_OFFSET_NAME(50),
310 REGS_OFFSET_NAME(51),
311 REGS_OFFSET_NAME(52),
312 REGS_OFFSET_NAME(53),
313 REGS_OFFSET_NAME(54),
314 REGS_OFFSET_NAME(55),
315 REGS_OFFSET_NAME(56),
316 REGS_OFFSET_NAME(57),
317 REGS_OFFSET_NAME(58),
318 REGS_OFFSET_NAME(59),
319 REGS_OFFSET_NAME(60),
320 REGS_OFFSET_NAME(61),
321 REGS_OFFSET_NAME(62),
322 REGS_OFFSET_NAME(63),
323 TREGS_OFFSET_NAME(0),
324 TREGS_OFFSET_NAME(1),
325 TREGS_OFFSET_NAME(2),
326 TREGS_OFFSET_NAME(3),
327 TREGS_OFFSET_NAME(4),
328 TREGS_OFFSET_NAME(5),
329 TREGS_OFFSET_NAME(6),
330 TREGS_OFFSET_NAME(7),
331 REG_OFFSET_END,
332 };
333
334 /*
335 * These are our native regset flavours.
336 */
337 enum sh_regset {
338 REGSET_GENERAL,
339 #ifdef CONFIG_SH_FPU
340 REGSET_FPU,
341 #endif
342 };
343
344 static const struct user_regset sh_regsets[] = {
345 /*
346 * Format is:
347 * PC, SR, SYSCALL,
348 * R1 --> R63,
349 * TR0 --> TR7,
350 */
351 [REGSET_GENERAL] = {
352 .core_note_type = NT_PRSTATUS,
353 .n = ELF_NGREG,
354 .size = sizeof(long long),
355 .align = sizeof(long long),
356 .get = genregs_get,
357 .set = genregs_set,
358 },
359
360 #ifdef CONFIG_SH_FPU
361 [REGSET_FPU] = {
362 .core_note_type = NT_PRFPREG,
363 .n = sizeof(struct user_fpu_struct) /
364 sizeof(long long),
365 .size = sizeof(long long),
366 .align = sizeof(long long),
367 .get = fpregs_get,
368 .set = fpregs_set,
369 .active = fpregs_active,
370 },
371 #endif
372 };
373
374 static const struct user_regset_view user_sh64_native_view = {
375 .name = "sh64",
376 .e_machine = EM_SH,
377 .regsets = sh_regsets,
378 .n = ARRAY_SIZE(sh_regsets),
379 };
380
381 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
382 {
383 return &user_sh64_native_view;
384 }
385
386 long arch_ptrace(struct task_struct *child, long request,
387 unsigned long addr, unsigned long data)
388 {
389 int ret;
390 unsigned long __user *datap = (unsigned long __user *) data;
391
392 switch (request) {
393 /* read the word at location addr in the USER area. */
394 case PTRACE_PEEKUSR: {
395 unsigned long tmp;
396
397 ret = -EIO;
398 if ((addr & 3) || addr < 0)
399 break;
400
401 if (addr < sizeof(struct pt_regs))
402 tmp = get_stack_long(child, addr);
403 else if ((addr >= offsetof(struct user, fpu)) &&
404 (addr < offsetof(struct user, u_fpvalid))) {
405 unsigned long index;
406 ret = init_fpu(child);
407 if (ret)
408 break;
409 index = addr - offsetof(struct user, fpu);
410 tmp = get_fpu_long(child, index);
411 } else if (addr == offsetof(struct user, u_fpvalid)) {
412 tmp = !!tsk_used_math(child);
413 } else {
414 break;
415 }
416 ret = put_user(tmp, datap);
417 break;
418 }
419
420 case PTRACE_POKEUSR:
421 /* write the word at location addr in the USER area. We must
422 disallow any changes to certain SR bits or u_fpvalid, since
423 this could crash the kernel or result in a security
424 loophole. */
425 ret = -EIO;
426 if ((addr & 3) || addr < 0)
427 break;
428
429 if (addr < sizeof(struct pt_regs)) {
430 /* Ignore change of top 32 bits of SR */
431 if (addr == offsetof (struct pt_regs, sr)+4)
432 {
433 ret = 0;
434 break;
435 }
436 /* If lower 32 bits of SR, ignore non-user bits */
437 if (addr == offsetof (struct pt_regs, sr))
438 {
439 long cursr = get_stack_long(child, addr);
440 data &= ~(SR_MASK);
441 data |= (cursr & SR_MASK);
442 }
443 ret = put_stack_long(child, addr, data);
444 }
445 else if ((addr >= offsetof(struct user, fpu)) &&
446 (addr < offsetof(struct user, u_fpvalid))) {
447 unsigned long index;
448 ret = init_fpu(child);
449 if (ret)
450 break;
451 index = addr - offsetof(struct user, fpu);
452 ret = put_fpu_long(child, index, data);
453 }
454 break;
455
456 case PTRACE_GETREGS:
457 return copy_regset_to_user(child, &user_sh64_native_view,
458 REGSET_GENERAL,
459 0, sizeof(struct pt_regs),
460 datap);
461 case PTRACE_SETREGS:
462 return copy_regset_from_user(child, &user_sh64_native_view,
463 REGSET_GENERAL,
464 0, sizeof(struct pt_regs),
465 datap);
466 #ifdef CONFIG_SH_FPU
467 case PTRACE_GETFPREGS:
468 return copy_regset_to_user(child, &user_sh64_native_view,
469 REGSET_FPU,
470 0, sizeof(struct user_fpu_struct),
471 datap);
472 case PTRACE_SETFPREGS:
473 return copy_regset_from_user(child, &user_sh64_native_view,
474 REGSET_FPU,
475 0, sizeof(struct user_fpu_struct),
476 datap);
477 #endif
478 default:
479 ret = ptrace_request(child, request, addr, data);
480 break;
481 }
482
483 return ret;
484 }
485
486 asmlinkage int sh64_ptrace(long request, long pid,
487 unsigned long addr, unsigned long data)
488 {
489 #define WPC_DBRMODE 0x0d104008
490 static unsigned long first_call;
491
492 if (!test_and_set_bit(0, &first_call)) {
493 /* Set WPC.DBRMODE to 0. This makes all debug events get
494 * delivered through RESVEC, i.e. into the handlers in entry.S.
495 * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE
496 * would normally be left set to 1, which makes debug events get
497 * delivered through DBRVEC, i.e. into the remote gdb's
498 * handlers. This prevents ptrace getting them, and confuses
499 * the remote gdb.) */
500 printk("DBRMODE set to 0 to permit native debugging\n");
501 poke_real_address_q(WPC_DBRMODE, 0);
502 }
503
504 return sys_ptrace(request, pid, addr, data);
505 }
506
507 static inline int audit_arch(void)
508 {
509 int arch = EM_SH;
510
511 #ifdef CONFIG_64BIT
512 arch |= __AUDIT_ARCH_64BIT;
513 #endif
514 #ifdef CONFIG_CPU_LITTLE_ENDIAN
515 arch |= __AUDIT_ARCH_LE;
516 #endif
517
518 return arch;
519 }
520
521 asmlinkage long long do_syscall_trace_enter(struct pt_regs *regs)
522 {
523 long long ret = 0;
524
525 secure_computing(regs->regs[9]);
526
527 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
528 tracehook_report_syscall_entry(regs))
529 /*
530 * Tracing decided this syscall should not happen.
531 * We'll return a bogus call number to get an ENOSYS
532 * error, but leave the original number in regs->regs[0].
533 */
534 ret = -1LL;
535
536 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
537 trace_sys_enter(regs, regs->regs[9]);
538
539 if (unlikely(current->audit_context))
540 audit_syscall_entry(audit_arch(), regs->regs[1],
541 regs->regs[2], regs->regs[3],
542 regs->regs[4], regs->regs[5]);
543
544 return ret ?: regs->regs[9];
545 }
546
547 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
548 {
549 int step;
550
551 if (unlikely(current->audit_context))
552 audit_syscall_exit(AUDITSC_RESULT(regs->regs[9]),
553 regs->regs[9]);
554
555 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
556 trace_sys_exit(regs, regs->regs[9]);
557
558 step = test_thread_flag(TIF_SINGLESTEP);
559 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
560 tracehook_report_syscall_exit(regs, step);
561 }
562
563 /* Called with interrupts disabled */
564 asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs)
565 {
566 /* This is called after a single step exception (DEBUGSS).
567 There is no need to change the PC, as it is a post-execution
568 exception, as entry.S does not do anything to the PC for DEBUGSS.
569 We need to clear the Single Step setting in SR to avoid
570 continually stepping. */
571 local_irq_enable();
572 regs->sr &= ~SR_SSTEP;
573 force_sig(SIGTRAP, current);
574 }
575
576 /* Called with interrupts disabled */
577 BUILD_TRAP_HANDLER(breakpoint)
578 {
579 TRAP_HANDLER_DECL;
580
581 /* We need to forward step the PC, to counteract the backstep done
582 in signal.c. */
583 local_irq_enable();
584 force_sig(SIGTRAP, current);
585 regs->pc += 4;
586 }
587
588 /*
589 * Called by kernel/ptrace.c when detaching..
590 *
591 * Make sure single step bits etc are not set.
592 */
593 void ptrace_disable(struct task_struct *child)
594 {
595 user_disable_single_step(child);
596 }
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