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1da177e4 LT |
1 | /* |
2 | * linux/arch/m32r/kernel/ptrace.c | |
3 | * | |
4 | * Copyright (C) 2002 Hirokazu Takata, Takeo Takahashi | |
5 | * Copyright (C) 2004 Hirokazu Takata, Kei Sakamoto | |
6 | * | |
7 | * Original x86 implementation: | |
8 | * By Ross Biro 1/23/92 | |
9 | * edited by Linus Torvalds | |
10 | * | |
11 | * Some code taken from sh version: | |
12 | * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka | |
13 | * Some code taken from arm version: | |
14 | * Copyright (C) 2000 Russell King | |
15 | */ | |
16 | ||
17 | #include <linux/config.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/mm.h> | |
21 | #include <linux/smp.h> | |
22 | #include <linux/smp_lock.h> | |
23 | #include <linux/errno.h> | |
24 | #include <linux/ptrace.h> | |
25 | #include <linux/user.h> | |
26 | #include <linux/string.h> | |
27 | ||
28 | #include <asm/cacheflush.h> | |
29 | #include <asm/io.h> | |
30 | #include <asm/uaccess.h> | |
31 | #include <asm/pgtable.h> | |
32 | #include <asm/system.h> | |
33 | #include <asm/processor.h> | |
34 | #include <asm/mmu_context.h> | |
35 | ||
36 | /* | |
37 | * Get the address of the live pt_regs for the specified task. | |
38 | * These are saved onto the top kernel stack when the process | |
39 | * is not running. | |
40 | * | |
41 | * Note: if a user thread is execve'd from kernel space, the | |
42 | * kernel stack will not be empty on entry to the kernel, so | |
43 | * ptracing these tasks will fail. | |
44 | */ | |
45 | static inline struct pt_regs * | |
46 | get_user_regs(struct task_struct *task) | |
47 | { | |
48 | return (struct pt_regs *) | |
49 | ((unsigned long)task->thread_info + THREAD_SIZE | |
50 | - sizeof(struct pt_regs)); | |
51 | } | |
52 | ||
53 | /* | |
54 | * This routine will get a word off of the process kernel stack. | |
55 | */ | |
56 | static inline unsigned long int | |
57 | get_stack_long(struct task_struct *task, int offset) | |
58 | { | |
59 | unsigned long *stack; | |
60 | ||
61 | stack = (unsigned long *)get_user_regs(task); | |
62 | ||
63 | return stack[offset]; | |
64 | } | |
65 | ||
66 | /* | |
67 | * This routine will put a word on the process kernel stack. | |
68 | */ | |
69 | static inline int | |
70 | put_stack_long(struct task_struct *task, int offset, unsigned long data) | |
71 | { | |
72 | unsigned long *stack; | |
73 | ||
74 | stack = (unsigned long *)get_user_regs(task); | |
75 | stack[offset] = data; | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static int reg_offset[] = { | |
81 | PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7, | |
82 | PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_FP, PT_LR, PT_SPU, | |
83 | }; | |
84 | ||
85 | /* | |
86 | * Read the word at offset "off" into the "struct user". We | |
87 | * actually access the pt_regs stored on the kernel stack. | |
88 | */ | |
89 | static int ptrace_read_user(struct task_struct *tsk, unsigned long off, | |
90 | unsigned long __user *data) | |
91 | { | |
92 | unsigned long tmp; | |
93 | #ifndef NO_FPU | |
94 | struct user * dummy = NULL; | |
95 | #endif | |
96 | ||
97 | if ((off & 3) || (off < 0) || (off > sizeof(struct user) - 3)) | |
98 | return -EIO; | |
99 | ||
100 | off >>= 2; | |
101 | switch (off) { | |
102 | case PT_EVB: | |
103 | __asm__ __volatile__ ( | |
104 | "mvfc %0, cr5 \n\t" | |
105 | : "=r" (tmp) | |
106 | ); | |
107 | break; | |
108 | case PT_CBR: { | |
109 | unsigned long psw; | |
110 | psw = get_stack_long(tsk, PT_PSW); | |
111 | tmp = ((psw >> 8) & 1); | |
112 | } | |
113 | break; | |
114 | case PT_PSW: { | |
115 | unsigned long psw, bbpsw; | |
116 | psw = get_stack_long(tsk, PT_PSW); | |
117 | bbpsw = get_stack_long(tsk, PT_BBPSW); | |
118 | tmp = ((psw >> 8) & 0xff) | ((bbpsw & 0xff) << 8); | |
119 | } | |
120 | break; | |
121 | case PT_PC: | |
122 | tmp = get_stack_long(tsk, PT_BPC); | |
123 | break; | |
124 | case PT_BPC: | |
125 | off = PT_BBPC; | |
126 | /* fall through */ | |
127 | default: | |
128 | if (off < (sizeof(struct pt_regs) >> 2)) | |
129 | tmp = get_stack_long(tsk, off); | |
130 | #ifndef NO_FPU | |
131 | else if (off >= (long)(&dummy->fpu >> 2) && | |
132 | off < (long)(&dummy->u_fpvalid >> 2)) { | |
133 | if (!tsk_used_math(tsk)) { | |
134 | if (off == (long)(&dummy->fpu.fpscr >> 2)) | |
135 | tmp = FPSCR_INIT; | |
136 | else | |
137 | tmp = 0; | |
138 | } else | |
139 | tmp = ((long *)(&tsk->thread.fpu >> 2)) | |
140 | [off - (long)&dummy->fpu]; | |
141 | } else if (off == (long)(&dummy->u_fpvalid >> 2)) | |
142 | tmp = !!tsk_used_math(tsk); | |
143 | #endif /* not NO_FPU */ | |
144 | else | |
145 | tmp = 0; | |
146 | } | |
147 | ||
148 | return put_user(tmp, data); | |
149 | } | |
150 | ||
151 | static int ptrace_write_user(struct task_struct *tsk, unsigned long off, | |
152 | unsigned long data) | |
153 | { | |
154 | int ret = -EIO; | |
155 | #ifndef NO_FPU | |
156 | struct user * dummy = NULL; | |
157 | #endif | |
158 | ||
159 | if ((off & 3) || off < 0 || | |
160 | off > sizeof(struct user) - 3) | |
161 | return -EIO; | |
162 | ||
163 | off >>= 2; | |
164 | switch (off) { | |
165 | case PT_EVB: | |
166 | case PT_BPC: | |
167 | case PT_SPI: | |
168 | /* We don't allow to modify evb. */ | |
169 | ret = 0; | |
170 | break; | |
171 | case PT_PSW: | |
172 | case PT_CBR: { | |
173 | /* We allow to modify only cbr in psw */ | |
174 | unsigned long psw; | |
175 | psw = get_stack_long(tsk, PT_PSW); | |
176 | psw = (psw & ~0x100) | ((data & 1) << 8); | |
177 | ret = put_stack_long(tsk, PT_PSW, psw); | |
178 | } | |
179 | break; | |
180 | case PT_PC: | |
181 | off = PT_BPC; | |
182 | data &= ~1; | |
183 | /* fall through */ | |
184 | default: | |
185 | if (off < (sizeof(struct pt_regs) >> 2)) | |
186 | ret = put_stack_long(tsk, off, data); | |
187 | #ifndef NO_FPU | |
188 | else if (off >= (long)(&dummy->fpu >> 2) && | |
189 | off < (long)(&dummy->u_fpvalid >> 2)) { | |
190 | set_stopped_child_used_math(tsk); | |
191 | ((long *)&tsk->thread.fpu) | |
192 | [off - (long)&dummy->fpu] = data; | |
193 | ret = 0; | |
194 | } else if (off == (long)(&dummy->u_fpvalid >> 2)) { | |
195 | conditional_stopped_child_used_math(data, tsk); | |
196 | ret = 0; | |
197 | } | |
198 | #endif /* not NO_FPU */ | |
199 | break; | |
200 | } | |
201 | ||
202 | return ret; | |
203 | } | |
204 | ||
205 | /* | |
206 | * Get all user integer registers. | |
207 | */ | |
208 | static int ptrace_getregs(struct task_struct *tsk, void __user *uregs) | |
209 | { | |
210 | struct pt_regs *regs = get_user_regs(tsk); | |
211 | ||
212 | return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0; | |
213 | } | |
214 | ||
215 | /* | |
216 | * Set all user integer registers. | |
217 | */ | |
218 | static int ptrace_setregs(struct task_struct *tsk, void __user *uregs) | |
219 | { | |
220 | struct pt_regs newregs; | |
221 | int ret; | |
222 | ||
223 | ret = -EFAULT; | |
224 | if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) { | |
225 | struct pt_regs *regs = get_user_regs(tsk); | |
226 | *regs = newregs; | |
227 | ret = 0; | |
228 | } | |
229 | ||
230 | return ret; | |
231 | } | |
232 | ||
233 | ||
234 | static inline int | |
235 | check_condition_bit(struct task_struct *child) | |
236 | { | |
237 | return (int)((get_stack_long(child, PT_PSW) >> 8) & 1); | |
238 | } | |
239 | ||
240 | static int | |
241 | check_condition_src(unsigned long op, unsigned long regno1, | |
242 | unsigned long regno2, struct task_struct *child) | |
243 | { | |
244 | unsigned long reg1, reg2; | |
245 | ||
246 | reg2 = get_stack_long(child, reg_offset[regno2]); | |
247 | ||
248 | switch (op) { | |
249 | case 0x0: /* BEQ */ | |
250 | reg1 = get_stack_long(child, reg_offset[regno1]); | |
251 | return reg1 == reg2; | |
252 | case 0x1: /* BNE */ | |
253 | reg1 = get_stack_long(child, reg_offset[regno1]); | |
254 | return reg1 != reg2; | |
255 | case 0x8: /* BEQZ */ | |
256 | return reg2 == 0; | |
257 | case 0x9: /* BNEZ */ | |
258 | return reg2 != 0; | |
259 | case 0xa: /* BLTZ */ | |
260 | return (int)reg2 < 0; | |
261 | case 0xb: /* BGEZ */ | |
262 | return (int)reg2 >= 0; | |
263 | case 0xc: /* BLEZ */ | |
264 | return (int)reg2 <= 0; | |
265 | case 0xd: /* BGTZ */ | |
266 | return (int)reg2 > 0; | |
267 | default: | |
268 | /* never reached */ | |
269 | return 0; | |
270 | } | |
271 | } | |
272 | ||
273 | static void | |
274 | compute_next_pc_for_16bit_insn(unsigned long insn, unsigned long pc, | |
275 | unsigned long *next_pc, | |
276 | struct task_struct *child) | |
277 | { | |
278 | unsigned long op, op2, op3; | |
279 | unsigned long disp; | |
280 | unsigned long regno; | |
281 | int parallel = 0; | |
282 | ||
283 | if (insn & 0x00008000) | |
284 | parallel = 1; | |
285 | if (pc & 3) | |
286 | insn &= 0x7fff; /* right slot */ | |
287 | else | |
288 | insn >>= 16; /* left slot */ | |
289 | ||
290 | op = (insn >> 12) & 0xf; | |
291 | op2 = (insn >> 8) & 0xf; | |
292 | op3 = (insn >> 4) & 0xf; | |
293 | ||
294 | if (op == 0x7) { | |
295 | switch (op2) { | |
296 | case 0xd: /* BNC */ | |
297 | case 0x9: /* BNCL */ | |
298 | if (!check_condition_bit(child)) { | |
299 | disp = (long)(insn << 24) >> 22; | |
300 | *next_pc = (pc & ~0x3) + disp; | |
301 | return; | |
302 | } | |
303 | break; | |
304 | case 0x8: /* BCL */ | |
305 | case 0xc: /* BC */ | |
306 | if (check_condition_bit(child)) { | |
307 | disp = (long)(insn << 24) >> 22; | |
308 | *next_pc = (pc & ~0x3) + disp; | |
309 | return; | |
310 | } | |
311 | break; | |
312 | case 0xe: /* BL */ | |
313 | case 0xf: /* BRA */ | |
314 | disp = (long)(insn << 24) >> 22; | |
315 | *next_pc = (pc & ~0x3) + disp; | |
316 | return; | |
317 | break; | |
318 | } | |
319 | } else if (op == 0x1) { | |
320 | switch (op2) { | |
321 | case 0x0: | |
322 | if (op3 == 0xf) { /* TRAP */ | |
323 | #if 1 | |
324 | /* pass through */ | |
325 | #else | |
326 | /* kernel space is not allowed as next_pc */ | |
327 | unsigned long evb; | |
328 | unsigned long trapno; | |
329 | trapno = insn & 0xf; | |
330 | __asm__ __volatile__ ( | |
331 | "mvfc %0, cr5\n" | |
332 | :"=r"(evb) | |
333 | : | |
334 | ); | |
335 | *next_pc = evb + (trapno << 2); | |
336 | return; | |
337 | #endif | |
338 | } else if (op3 == 0xd) { /* RTE */ | |
339 | *next_pc = get_stack_long(child, PT_BPC); | |
340 | return; | |
341 | } | |
342 | break; | |
343 | case 0xc: /* JC */ | |
344 | if (op3 == 0xc && check_condition_bit(child)) { | |
345 | regno = insn & 0xf; | |
346 | *next_pc = get_stack_long(child, | |
347 | reg_offset[regno]); | |
348 | return; | |
349 | } | |
350 | break; | |
351 | case 0xd: /* JNC */ | |
352 | if (op3 == 0xc && !check_condition_bit(child)) { | |
353 | regno = insn & 0xf; | |
354 | *next_pc = get_stack_long(child, | |
355 | reg_offset[regno]); | |
356 | return; | |
357 | } | |
358 | break; | |
359 | case 0xe: /* JL */ | |
360 | case 0xf: /* JMP */ | |
361 | if (op3 == 0xc) { /* JMP */ | |
362 | regno = insn & 0xf; | |
363 | *next_pc = get_stack_long(child, | |
364 | reg_offset[regno]); | |
365 | return; | |
366 | } | |
367 | break; | |
368 | } | |
369 | } | |
370 | if (parallel) | |
371 | *next_pc = pc + 4; | |
372 | else | |
373 | *next_pc = pc + 2; | |
374 | } | |
375 | ||
376 | static void | |
377 | compute_next_pc_for_32bit_insn(unsigned long insn, unsigned long pc, | |
378 | unsigned long *next_pc, | |
379 | struct task_struct *child) | |
380 | { | |
381 | unsigned long op; | |
382 | unsigned long op2; | |
383 | unsigned long disp; | |
384 | unsigned long regno1, regno2; | |
385 | ||
386 | op = (insn >> 28) & 0xf; | |
387 | if (op == 0xf) { /* branch 24-bit relative */ | |
388 | op2 = (insn >> 24) & 0xf; | |
389 | switch (op2) { | |
390 | case 0xd: /* BNC */ | |
391 | case 0x9: /* BNCL */ | |
392 | if (!check_condition_bit(child)) { | |
393 | disp = (long)(insn << 8) >> 6; | |
394 | *next_pc = (pc & ~0x3) + disp; | |
395 | return; | |
396 | } | |
397 | break; | |
398 | case 0x8: /* BCL */ | |
399 | case 0xc: /* BC */ | |
400 | if (check_condition_bit(child)) { | |
401 | disp = (long)(insn << 8) >> 6; | |
402 | *next_pc = (pc & ~0x3) + disp; | |
403 | return; | |
404 | } | |
405 | break; | |
406 | case 0xe: /* BL */ | |
407 | case 0xf: /* BRA */ | |
408 | disp = (long)(insn << 8) >> 6; | |
409 | *next_pc = (pc & ~0x3) + disp; | |
410 | return; | |
411 | } | |
412 | } else if (op == 0xb) { /* branch 16-bit relative */ | |
413 | op2 = (insn >> 20) & 0xf; | |
414 | switch (op2) { | |
415 | case 0x0: /* BEQ */ | |
416 | case 0x1: /* BNE */ | |
417 | case 0x8: /* BEQZ */ | |
418 | case 0x9: /* BNEZ */ | |
419 | case 0xa: /* BLTZ */ | |
420 | case 0xb: /* BGEZ */ | |
421 | case 0xc: /* BLEZ */ | |
422 | case 0xd: /* BGTZ */ | |
423 | regno1 = ((insn >> 24) & 0xf); | |
424 | regno2 = ((insn >> 16) & 0xf); | |
425 | if (check_condition_src(op2, regno1, regno2, child)) { | |
426 | disp = (long)(insn << 16) >> 14; | |
427 | *next_pc = (pc & ~0x3) + disp; | |
428 | return; | |
429 | } | |
430 | break; | |
431 | } | |
432 | } | |
433 | *next_pc = pc + 4; | |
434 | } | |
435 | ||
436 | static inline void | |
437 | compute_next_pc(unsigned long insn, unsigned long pc, | |
438 | unsigned long *next_pc, struct task_struct *child) | |
439 | { | |
440 | if (insn & 0x80000000) | |
441 | compute_next_pc_for_32bit_insn(insn, pc, next_pc, child); | |
442 | else | |
443 | compute_next_pc_for_16bit_insn(insn, pc, next_pc, child); | |
444 | } | |
445 | ||
446 | static int | |
447 | register_debug_trap(struct task_struct *child, unsigned long next_pc, | |
448 | unsigned long next_insn, unsigned long *code) | |
449 | { | |
450 | struct debug_trap *p = &child->thread.debug_trap; | |
451 | unsigned long addr = next_pc & ~3; | |
452 | ||
453 | if (p->nr_trap == MAX_TRAPS) { | |
454 | printk("kernel BUG at %s %d: p->nr_trap = %d\n", | |
455 | __FILE__, __LINE__, p->nr_trap); | |
456 | return -1; | |
457 | } | |
458 | p->addr[p->nr_trap] = addr; | |
459 | p->insn[p->nr_trap] = next_insn; | |
460 | p->nr_trap++; | |
461 | if (next_pc & 3) { | |
462 | *code = (next_insn & 0xffff0000) | 0x10f1; | |
463 | /* xxx --> TRAP1 */ | |
464 | } else { | |
465 | if ((next_insn & 0x80000000) || (next_insn & 0x8000)) { | |
466 | *code = 0x10f17000; | |
467 | /* TRAP1 --> NOP */ | |
468 | } else { | |
469 | *code = (next_insn & 0xffff) | 0x10f10000; | |
470 | /* TRAP1 --> xxx */ | |
471 | } | |
472 | } | |
473 | return 0; | |
474 | } | |
475 | ||
476 | static int | |
477 | unregister_debug_trap(struct task_struct *child, unsigned long addr, | |
478 | unsigned long *code) | |
479 | { | |
480 | struct debug_trap *p = &child->thread.debug_trap; | |
481 | int i; | |
482 | ||
483 | /* Search debug trap entry. */ | |
484 | for (i = 0; i < p->nr_trap; i++) { | |
485 | if (p->addr[i] == addr) | |
486 | break; | |
487 | } | |
488 | if (i >= p->nr_trap) { | |
489 | /* The trap may be requested from debugger. | |
490 | * ptrace should do nothing in this case. | |
491 | */ | |
492 | return 0; | |
493 | } | |
494 | ||
495 | /* Recover orignal instruction code. */ | |
496 | *code = p->insn[i]; | |
497 | ||
498 | /* Shift debug trap entries. */ | |
499 | while (i < p->nr_trap - 1) { | |
500 | p->insn[i] = p->insn[i + 1]; | |
501 | p->addr[i] = p->addr[i + 1]; | |
502 | i++; | |
503 | } | |
504 | p->nr_trap--; | |
505 | return 1; | |
506 | } | |
507 | ||
508 | static void | |
509 | unregister_all_debug_traps(struct task_struct *child) | |
510 | { | |
511 | struct debug_trap *p = &child->thread.debug_trap; | |
512 | int i; | |
513 | ||
514 | for (i = 0; i < p->nr_trap; i++) | |
515 | access_process_vm(child, p->addr[i], &p->insn[i], sizeof(p->insn[i]), 1); | |
516 | p->nr_trap = 0; | |
517 | } | |
518 | ||
519 | static inline void | |
520 | invalidate_cache(void) | |
521 | { | |
522 | #if defined(CONFIG_CHIP_M32700) || defined(CONFIG_CHIP_OPSP) | |
523 | ||
524 | _flush_cache_copyback_all(); | |
525 | ||
526 | #else /* ! CONFIG_CHIP_M32700 */ | |
527 | ||
528 | /* Invalidate cache */ | |
529 | __asm__ __volatile__ ( | |
530 | "ldi r0, #-1 \n\t" | |
531 | "ldi r1, #0 \n\t" | |
532 | "stb r1, @r0 ; cache off \n\t" | |
533 | "; \n\t" | |
534 | "ldi r0, #-2 \n\t" | |
535 | "ldi r1, #1 \n\t" | |
536 | "stb r1, @r0 ; cache invalidate \n\t" | |
537 | ".fillinsn \n" | |
538 | "0: \n\t" | |
539 | "ldb r1, @r0 ; invalidate check \n\t" | |
540 | "bnez r1, 0b \n\t" | |
541 | "; \n\t" | |
542 | "ldi r0, #-1 \n\t" | |
543 | "ldi r1, #1 \n\t" | |
544 | "stb r1, @r0 ; cache on \n\t" | |
545 | : : : "r0", "r1", "memory" | |
546 | ); | |
547 | /* FIXME: copying-back d-cache and invalidating i-cache are needed. | |
548 | */ | |
549 | #endif /* CONFIG_CHIP_M32700 */ | |
550 | } | |
551 | ||
552 | /* Embed a debug trap (TRAP1) code */ | |
553 | static int | |
554 | embed_debug_trap(struct task_struct *child, unsigned long next_pc) | |
555 | { | |
556 | unsigned long next_insn, code; | |
557 | unsigned long addr = next_pc & ~3; | |
558 | ||
559 | if (access_process_vm(child, addr, &next_insn, sizeof(next_insn), 0) | |
560 | != sizeof(next_insn)) { | |
561 | return -1; /* error */ | |
562 | } | |
563 | ||
564 | /* Set a trap code. */ | |
565 | if (register_debug_trap(child, next_pc, next_insn, &code)) { | |
566 | return -1; /* error */ | |
567 | } | |
568 | if (access_process_vm(child, addr, &code, sizeof(code), 1) | |
569 | != sizeof(code)) { | |
570 | return -1; /* error */ | |
571 | } | |
572 | return 0; /* success */ | |
573 | } | |
574 | ||
575 | void | |
576 | withdraw_debug_trap(struct pt_regs *regs) | |
577 | { | |
578 | unsigned long addr; | |
579 | unsigned long code; | |
580 | ||
581 | addr = (regs->bpc - 2) & ~3; | |
582 | regs->bpc -= 2; | |
583 | if (unregister_debug_trap(current, addr, &code)) { | |
584 | access_process_vm(current, addr, &code, sizeof(code), 1); | |
585 | invalidate_cache(); | |
586 | } | |
587 | } | |
588 | ||
589 | static void | |
590 | init_debug_traps(struct task_struct *child) | |
591 | { | |
592 | struct debug_trap *p = &child->thread.debug_trap; | |
593 | int i; | |
594 | p->nr_trap = 0; | |
595 | for (i = 0; i < MAX_TRAPS; i++) { | |
596 | p->addr[i] = 0; | |
597 | p->insn[i] = 0; | |
598 | } | |
599 | } | |
600 | ||
601 | ||
602 | /* | |
603 | * Called by kernel/ptrace.c when detaching.. | |
604 | * | |
605 | * Make sure single step bits etc are not set. | |
606 | */ | |
607 | void ptrace_disable(struct task_struct *child) | |
608 | { | |
609 | /* nothing to do.. */ | |
610 | } | |
611 | ||
612 | static int | |
613 | do_ptrace(long request, struct task_struct *child, long addr, long data) | |
614 | { | |
615 | unsigned long tmp; | |
616 | int ret; | |
617 | ||
618 | switch (request) { | |
619 | /* | |
620 | * read word at location "addr" in the child process. | |
621 | */ | |
622 | case PTRACE_PEEKTEXT: | |
623 | case PTRACE_PEEKDATA: | |
624 | ret = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
625 | if (ret == sizeof(tmp)) | |
626 | ret = put_user(tmp,(unsigned long __user *) data); | |
627 | else | |
628 | ret = -EIO; | |
629 | break; | |
630 | ||
631 | /* | |
632 | * read the word at location addr in the USER area. | |
633 | */ | |
634 | case PTRACE_PEEKUSR: | |
635 | ret = ptrace_read_user(child, addr, | |
636 | (unsigned long __user *)data); | |
637 | break; | |
638 | ||
639 | /* | |
640 | * write the word at location addr. | |
641 | */ | |
642 | case PTRACE_POKETEXT: | |
643 | case PTRACE_POKEDATA: | |
644 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
645 | if (ret == sizeof(data)) { | |
646 | ret = 0; | |
647 | if (request == PTRACE_POKETEXT) { | |
648 | invalidate_cache(); | |
649 | } | |
650 | } else { | |
651 | ret = -EIO; | |
652 | } | |
653 | break; | |
654 | ||
655 | /* | |
656 | * write the word at location addr in the USER area. | |
657 | */ | |
658 | case PTRACE_POKEUSR: | |
659 | ret = ptrace_write_user(child, addr, data); | |
660 | break; | |
661 | ||
662 | /* | |
663 | * continue/restart and stop at next (return from) syscall | |
664 | */ | |
665 | case PTRACE_SYSCALL: | |
666 | case PTRACE_CONT: | |
667 | ret = -EIO; | |
668 | if ((unsigned long) data > _NSIG) | |
669 | break; | |
670 | if (request == PTRACE_SYSCALL) | |
671 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
672 | else | |
673 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
674 | child->exit_code = data; | |
675 | wake_up_process(child); | |
676 | ret = 0; | |
677 | break; | |
678 | ||
679 | /* | |
680 | * make the child exit. Best I can do is send it a sigkill. | |
681 | * perhaps it should be put in the status that it wants to | |
682 | * exit. | |
683 | */ | |
684 | case PTRACE_KILL: { | |
685 | ret = 0; | |
686 | unregister_all_debug_traps(child); | |
687 | invalidate_cache(); | |
688 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
689 | break; | |
690 | child->exit_code = SIGKILL; | |
691 | wake_up_process(child); | |
692 | break; | |
693 | } | |
694 | ||
695 | /* | |
696 | * execute single instruction. | |
697 | */ | |
698 | case PTRACE_SINGLESTEP: { | |
699 | unsigned long next_pc; | |
700 | unsigned long pc, insn; | |
701 | ||
702 | ret = -EIO; | |
703 | if ((unsigned long) data > _NSIG) | |
704 | break; | |
705 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
706 | if ((child->ptrace & PT_DTRACE) == 0) { | |
707 | /* Spurious delayed TF traps may occur */ | |
708 | child->ptrace |= PT_DTRACE; | |
709 | } | |
710 | ||
711 | /* Compute next pc. */ | |
712 | pc = get_stack_long(child, PT_BPC); | |
713 | ||
714 | if (access_process_vm(child, pc&~3, &insn, sizeof(insn), 0) | |
715 | != sizeof(insn)) | |
716 | break; | |
717 | ||
718 | compute_next_pc(insn, pc, &next_pc, child); | |
719 | if (next_pc & 0x80000000) | |
720 | break; | |
721 | ||
722 | if (embed_debug_trap(child, next_pc)) | |
723 | break; | |
724 | ||
725 | invalidate_cache(); | |
726 | child->exit_code = data; | |
727 | ||
728 | /* give it a chance to run. */ | |
729 | wake_up_process(child); | |
730 | ret = 0; | |
731 | break; | |
732 | } | |
733 | ||
734 | /* | |
735 | * detach a process that was attached. | |
736 | */ | |
737 | case PTRACE_DETACH: | |
738 | ret = 0; | |
739 | ret = ptrace_detach(child, data); | |
740 | break; | |
741 | ||
742 | case PTRACE_GETREGS: | |
743 | ret = ptrace_getregs(child, (void __user *)data); | |
744 | break; | |
745 | ||
746 | case PTRACE_SETREGS: | |
747 | ret = ptrace_setregs(child, (void __user *)data); | |
748 | break; | |
749 | ||
750 | default: | |
751 | ret = ptrace_request(child, request, addr, data); | |
752 | break; | |
753 | } | |
754 | ||
755 | return ret; | |
756 | } | |
757 | ||
758 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
759 | { | |
760 | struct task_struct *child; | |
761 | int ret; | |
762 | ||
763 | lock_kernel(); | |
764 | ret = -EPERM; | |
765 | if (request == PTRACE_TRACEME) { | |
766 | /* are we already being traced? */ | |
767 | if (current->ptrace & PT_PTRACED) | |
768 | goto out; | |
769 | /* set the ptrace bit in the process flags. */ | |
770 | current->ptrace |= PT_PTRACED; | |
771 | ret = 0; | |
772 | goto out; | |
773 | } | |
774 | ret = -ESRCH; | |
775 | read_lock(&tasklist_lock); | |
776 | child = find_task_by_pid(pid); | |
777 | if (child) | |
778 | get_task_struct(child); | |
779 | read_unlock(&tasklist_lock); | |
780 | if (!child) | |
781 | goto out; | |
782 | ||
783 | ret = -EPERM; | |
784 | if (pid == 1) /* you may not mess with init */ | |
785 | goto out; | |
786 | ||
787 | if (request == PTRACE_ATTACH) { | |
788 | ret = ptrace_attach(child); | |
789 | if (ret == 0) | |
790 | init_debug_traps(child); | |
791 | goto out_tsk; | |
792 | } | |
793 | ||
794 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
795 | if (ret == 0) | |
796 | ret = do_ptrace(request, child, addr, data); | |
797 | ||
798 | out_tsk: | |
799 | put_task_struct(child); | |
800 | out: | |
801 | unlock_kernel(); | |
802 | ||
803 | return ret; | |
804 | } | |
805 | ||
806 | /* notification of system call entry/exit | |
807 | * - triggered by current->work.syscall_trace | |
808 | */ | |
809 | void do_syscall_trace(void) | |
810 | { | |
811 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
812 | return; | |
813 | if (!(current->ptrace & PT_PTRACED)) | |
814 | return; | |
815 | /* the 0x80 provides a way for the tracing parent to distinguish | |
816 | between a syscall stop and SIGTRAP delivery */ | |
817 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
818 | ? 0x80 : 0)); | |
819 | ||
820 | /* | |
821 | * this isn't the same as continuing with a signal, but it will do | |
822 | * for normal use. strace only continues with a signal if the | |
823 | * stopping signal is not SIGTRAP. -brl | |
824 | */ | |
825 | if (current->exit_code) { | |
826 | send_sig(current->exit_code, current, 1); | |
827 | current->exit_code = 0; | |
828 | } | |
829 | } |