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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/ptrace.c | |
3 | * | |
4 | * By Ross Biro 1/23/92 | |
5 | * edited by Linus Torvalds | |
6 | * ARM modifications Copyright (C) 2000 Russell King | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | #include <linux/config.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/smp.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/ptrace.h> | |
19 | #include <linux/user.h> | |
20 | #include <linux/security.h> | |
21 | #include <linux/init.h> | |
7ed20e1a | 22 | #include <linux/signal.h> |
1da177e4 LT |
23 | |
24 | #include <asm/uaccess.h> | |
25 | #include <asm/pgtable.h> | |
26 | #include <asm/system.h> | |
27 | #include <asm/traps.h> | |
28 | ||
29 | #include "ptrace.h" | |
30 | ||
31 | #define REG_PC 15 | |
32 | #define REG_PSR 16 | |
33 | /* | |
34 | * does not yet catch signals sent when the child dies. | |
35 | * in exit.c or in signal.c. | |
36 | */ | |
37 | ||
38 | #if 0 | |
39 | /* | |
40 | * Breakpoint SWI instruction: SWI &9F0001 | |
41 | */ | |
42 | #define BREAKINST_ARM 0xef9f0001 | |
43 | #define BREAKINST_THUMB 0xdf00 /* fill this in later */ | |
44 | #else | |
45 | /* | |
46 | * New breakpoints - use an undefined instruction. The ARM architecture | |
47 | * reference manual guarantees that the following instruction space | |
48 | * will produce an undefined instruction exception on all CPUs: | |
49 | * | |
50 | * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx | |
51 | * Thumb: 1101 1110 xxxx xxxx | |
52 | */ | |
53 | #define BREAKINST_ARM 0xe7f001f0 | |
54 | #define BREAKINST_THUMB 0xde01 | |
55 | #endif | |
56 | ||
57 | /* | |
58 | * Get the address of the live pt_regs for the specified task. | |
59 | * These are saved onto the top kernel stack when the process | |
60 | * is not running. | |
61 | * | |
62 | * Note: if a user thread is execve'd from kernel space, the | |
63 | * kernel stack will not be empty on entry to the kernel, so | |
64 | * ptracing these tasks will fail. | |
65 | */ | |
66 | static inline struct pt_regs * | |
67 | get_user_regs(struct task_struct *task) | |
68 | { | |
69 | return (struct pt_regs *) | |
70 | ((unsigned long)task->thread_info + THREAD_SIZE - | |
71 | 8 - sizeof(struct pt_regs)); | |
72 | } | |
73 | ||
74 | /* | |
75 | * this routine will get a word off of the processes privileged stack. | |
76 | * the offset is how far from the base addr as stored in the THREAD. | |
77 | * this routine assumes that all the privileged stacks are in our | |
78 | * data space. | |
79 | */ | |
80 | static inline long get_user_reg(struct task_struct *task, int offset) | |
81 | { | |
82 | return get_user_regs(task)->uregs[offset]; | |
83 | } | |
84 | ||
85 | /* | |
86 | * this routine will put a word on the processes privileged stack. | |
87 | * the offset is how far from the base addr as stored in the THREAD. | |
88 | * this routine assumes that all the privileged stacks are in our | |
89 | * data space. | |
90 | */ | |
91 | static inline int | |
92 | put_user_reg(struct task_struct *task, int offset, long data) | |
93 | { | |
94 | struct pt_regs newregs, *regs = get_user_regs(task); | |
95 | int ret = -EINVAL; | |
96 | ||
97 | newregs = *regs; | |
98 | newregs.uregs[offset] = data; | |
99 | ||
100 | if (valid_user_regs(&newregs)) { | |
101 | regs->uregs[offset] = data; | |
102 | ret = 0; | |
103 | } | |
104 | ||
105 | return ret; | |
106 | } | |
107 | ||
108 | static inline int | |
109 | read_u32(struct task_struct *task, unsigned long addr, u32 *res) | |
110 | { | |
111 | int ret; | |
112 | ||
113 | ret = access_process_vm(task, addr, res, sizeof(*res), 0); | |
114 | ||
115 | return ret == sizeof(*res) ? 0 : -EIO; | |
116 | } | |
117 | ||
118 | static inline int | |
119 | read_instr(struct task_struct *task, unsigned long addr, u32 *res) | |
120 | { | |
121 | int ret; | |
122 | ||
123 | if (addr & 1) { | |
124 | u16 val; | |
125 | ret = access_process_vm(task, addr & ~1, &val, sizeof(val), 0); | |
126 | ret = ret == sizeof(val) ? 0 : -EIO; | |
127 | *res = val; | |
128 | } else { | |
129 | u32 val; | |
130 | ret = access_process_vm(task, addr & ~3, &val, sizeof(val), 0); | |
131 | ret = ret == sizeof(val) ? 0 : -EIO; | |
132 | *res = val; | |
133 | } | |
134 | return ret; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Get value of register `rn' (in the instruction) | |
139 | */ | |
140 | static unsigned long | |
141 | ptrace_getrn(struct task_struct *child, unsigned long insn) | |
142 | { | |
143 | unsigned int reg = (insn >> 16) & 15; | |
144 | unsigned long val; | |
145 | ||
146 | val = get_user_reg(child, reg); | |
147 | if (reg == 15) | |
148 | val = pc_pointer(val + 8); | |
149 | ||
150 | return val; | |
151 | } | |
152 | ||
153 | /* | |
154 | * Get value of operand 2 (in an ALU instruction) | |
155 | */ | |
156 | static unsigned long | |
157 | ptrace_getaluop2(struct task_struct *child, unsigned long insn) | |
158 | { | |
159 | unsigned long val; | |
160 | int shift; | |
161 | int type; | |
162 | ||
163 | if (insn & 1 << 25) { | |
164 | val = insn & 255; | |
165 | shift = (insn >> 8) & 15; | |
166 | type = 3; | |
167 | } else { | |
168 | val = get_user_reg (child, insn & 15); | |
169 | ||
170 | if (insn & (1 << 4)) | |
171 | shift = (int)get_user_reg (child, (insn >> 8) & 15); | |
172 | else | |
173 | shift = (insn >> 7) & 31; | |
174 | ||
175 | type = (insn >> 5) & 3; | |
176 | } | |
177 | ||
178 | switch (type) { | |
179 | case 0: val <<= shift; break; | |
180 | case 1: val >>= shift; break; | |
181 | case 2: | |
182 | val = (((signed long)val) >> shift); | |
183 | break; | |
184 | case 3: | |
185 | val = (val >> shift) | (val << (32 - shift)); | |
186 | break; | |
187 | } | |
188 | return val; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Get value of operand 2 (in a LDR instruction) | |
193 | */ | |
194 | static unsigned long | |
195 | ptrace_getldrop2(struct task_struct *child, unsigned long insn) | |
196 | { | |
197 | unsigned long val; | |
198 | int shift; | |
199 | int type; | |
200 | ||
201 | val = get_user_reg(child, insn & 15); | |
202 | shift = (insn >> 7) & 31; | |
203 | type = (insn >> 5) & 3; | |
204 | ||
205 | switch (type) { | |
206 | case 0: val <<= shift; break; | |
207 | case 1: val >>= shift; break; | |
208 | case 2: | |
209 | val = (((signed long)val) >> shift); | |
210 | break; | |
211 | case 3: | |
212 | val = (val >> shift) | (val << (32 - shift)); | |
213 | break; | |
214 | } | |
215 | return val; | |
216 | } | |
217 | ||
218 | #define OP_MASK 0x01e00000 | |
219 | #define OP_AND 0x00000000 | |
220 | #define OP_EOR 0x00200000 | |
221 | #define OP_SUB 0x00400000 | |
222 | #define OP_RSB 0x00600000 | |
223 | #define OP_ADD 0x00800000 | |
224 | #define OP_ADC 0x00a00000 | |
225 | #define OP_SBC 0x00c00000 | |
226 | #define OP_RSC 0x00e00000 | |
227 | #define OP_ORR 0x01800000 | |
228 | #define OP_MOV 0x01a00000 | |
229 | #define OP_BIC 0x01c00000 | |
230 | #define OP_MVN 0x01e00000 | |
231 | ||
232 | static unsigned long | |
233 | get_branch_address(struct task_struct *child, unsigned long pc, unsigned long insn) | |
234 | { | |
235 | u32 alt = 0; | |
236 | ||
237 | switch (insn & 0x0e000000) { | |
238 | case 0x00000000: | |
239 | case 0x02000000: { | |
240 | /* | |
241 | * data processing | |
242 | */ | |
243 | long aluop1, aluop2, ccbit; | |
244 | ||
245 | if ((insn & 0xf000) != 0xf000) | |
246 | break; | |
247 | ||
248 | aluop1 = ptrace_getrn(child, insn); | |
249 | aluop2 = ptrace_getaluop2(child, insn); | |
250 | ccbit = get_user_reg(child, REG_PSR) & PSR_C_BIT ? 1 : 0; | |
251 | ||
252 | switch (insn & OP_MASK) { | |
253 | case OP_AND: alt = aluop1 & aluop2; break; | |
254 | case OP_EOR: alt = aluop1 ^ aluop2; break; | |
255 | case OP_SUB: alt = aluop1 - aluop2; break; | |
256 | case OP_RSB: alt = aluop2 - aluop1; break; | |
257 | case OP_ADD: alt = aluop1 + aluop2; break; | |
258 | case OP_ADC: alt = aluop1 + aluop2 + ccbit; break; | |
259 | case OP_SBC: alt = aluop1 - aluop2 + ccbit; break; | |
260 | case OP_RSC: alt = aluop2 - aluop1 + ccbit; break; | |
261 | case OP_ORR: alt = aluop1 | aluop2; break; | |
262 | case OP_MOV: alt = aluop2; break; | |
263 | case OP_BIC: alt = aluop1 & ~aluop2; break; | |
264 | case OP_MVN: alt = ~aluop2; break; | |
265 | } | |
266 | break; | |
267 | } | |
268 | ||
269 | case 0x04000000: | |
270 | case 0x06000000: | |
271 | /* | |
272 | * ldr | |
273 | */ | |
274 | if ((insn & 0x0010f000) == 0x0010f000) { | |
275 | unsigned long base; | |
276 | ||
277 | base = ptrace_getrn(child, insn); | |
278 | if (insn & 1 << 24) { | |
279 | long aluop2; | |
280 | ||
281 | if (insn & 0x02000000) | |
282 | aluop2 = ptrace_getldrop2(child, insn); | |
283 | else | |
284 | aluop2 = insn & 0xfff; | |
285 | ||
286 | if (insn & 1 << 23) | |
287 | base += aluop2; | |
288 | else | |
289 | base -= aluop2; | |
290 | } | |
291 | if (read_u32(child, base, &alt) == 0) | |
292 | alt = pc_pointer(alt); | |
293 | } | |
294 | break; | |
295 | ||
296 | case 0x08000000: | |
297 | /* | |
298 | * ldm | |
299 | */ | |
300 | if ((insn & 0x00108000) == 0x00108000) { | |
301 | unsigned long base; | |
302 | unsigned int nr_regs; | |
303 | ||
304 | if (insn & (1 << 23)) { | |
305 | nr_regs = hweight16(insn & 65535) << 2; | |
306 | ||
307 | if (!(insn & (1 << 24))) | |
308 | nr_regs -= 4; | |
309 | } else { | |
310 | if (insn & (1 << 24)) | |
311 | nr_regs = -4; | |
312 | else | |
313 | nr_regs = 0; | |
314 | } | |
315 | ||
316 | base = ptrace_getrn(child, insn); | |
317 | ||
318 | if (read_u32(child, base + nr_regs, &alt) == 0) | |
319 | alt = pc_pointer(alt); | |
320 | break; | |
321 | } | |
322 | break; | |
323 | ||
324 | case 0x0a000000: { | |
325 | /* | |
326 | * bl or b | |
327 | */ | |
328 | signed long displ; | |
329 | /* It's a branch/branch link: instead of trying to | |
330 | * figure out whether the branch will be taken or not, | |
331 | * we'll put a breakpoint at both locations. This is | |
332 | * simpler, more reliable, and probably not a whole lot | |
333 | * slower than the alternative approach of emulating the | |
334 | * branch. | |
335 | */ | |
336 | displ = (insn & 0x00ffffff) << 8; | |
337 | displ = (displ >> 6) + 8; | |
338 | if (displ != 0 && displ != 4) | |
339 | alt = pc + displ; | |
340 | } | |
341 | break; | |
342 | } | |
343 | ||
344 | return alt; | |
345 | } | |
346 | ||
347 | static int | |
348 | swap_insn(struct task_struct *task, unsigned long addr, | |
349 | void *old_insn, void *new_insn, int size) | |
350 | { | |
351 | int ret; | |
352 | ||
353 | ret = access_process_vm(task, addr, old_insn, size, 0); | |
354 | if (ret == size) | |
355 | ret = access_process_vm(task, addr, new_insn, size, 1); | |
356 | return ret; | |
357 | } | |
358 | ||
359 | static void | |
360 | add_breakpoint(struct task_struct *task, struct debug_info *dbg, unsigned long addr) | |
361 | { | |
362 | int nr = dbg->nsaved; | |
363 | ||
364 | if (nr < 2) { | |
365 | u32 new_insn = BREAKINST_ARM; | |
366 | int res; | |
367 | ||
368 | res = swap_insn(task, addr, &dbg->bp[nr].insn, &new_insn, 4); | |
369 | ||
370 | if (res == 4) { | |
371 | dbg->bp[nr].address = addr; | |
372 | dbg->nsaved += 1; | |
373 | } | |
374 | } else | |
375 | printk(KERN_ERR "ptrace: too many breakpoints\n"); | |
376 | } | |
377 | ||
378 | /* | |
379 | * Clear one breakpoint in the user program. We copy what the hardware | |
380 | * does and use bit 0 of the address to indicate whether this is a Thumb | |
381 | * breakpoint or an ARM breakpoint. | |
382 | */ | |
383 | static void clear_breakpoint(struct task_struct *task, struct debug_entry *bp) | |
384 | { | |
385 | unsigned long addr = bp->address; | |
386 | union debug_insn old_insn; | |
387 | int ret; | |
388 | ||
389 | if (addr & 1) { | |
390 | ret = swap_insn(task, addr & ~1, &old_insn.thumb, | |
391 | &bp->insn.thumb, 2); | |
392 | ||
393 | if (ret != 2 || old_insn.thumb != BREAKINST_THUMB) | |
394 | printk(KERN_ERR "%s:%d: corrupted Thumb breakpoint at " | |
395 | "0x%08lx (0x%04x)\n", task->comm, task->pid, | |
396 | addr, old_insn.thumb); | |
397 | } else { | |
398 | ret = swap_insn(task, addr & ~3, &old_insn.arm, | |
399 | &bp->insn.arm, 4); | |
400 | ||
401 | if (ret != 4 || old_insn.arm != BREAKINST_ARM) | |
402 | printk(KERN_ERR "%s:%d: corrupted ARM breakpoint at " | |
403 | "0x%08lx (0x%08x)\n", task->comm, task->pid, | |
404 | addr, old_insn.arm); | |
405 | } | |
406 | } | |
407 | ||
408 | void ptrace_set_bpt(struct task_struct *child) | |
409 | { | |
410 | struct pt_regs *regs; | |
411 | unsigned long pc; | |
412 | u32 insn; | |
413 | int res; | |
414 | ||
415 | regs = get_user_regs(child); | |
416 | pc = instruction_pointer(regs); | |
417 | ||
418 | if (thumb_mode(regs)) { | |
419 | printk(KERN_WARNING "ptrace: can't handle thumb mode\n"); | |
420 | return; | |
421 | } | |
422 | ||
423 | res = read_instr(child, pc, &insn); | |
424 | if (!res) { | |
425 | struct debug_info *dbg = &child->thread.debug; | |
426 | unsigned long alt; | |
427 | ||
428 | dbg->nsaved = 0; | |
429 | ||
430 | alt = get_branch_address(child, pc, insn); | |
431 | if (alt) | |
432 | add_breakpoint(child, dbg, alt); | |
433 | ||
434 | /* | |
435 | * Note that we ignore the result of setting the above | |
436 | * breakpoint since it may fail. When it does, this is | |
437 | * not so much an error, but a forewarning that we may | |
438 | * be receiving a prefetch abort shortly. | |
439 | * | |
440 | * If we don't set this breakpoint here, then we can | |
441 | * lose control of the thread during single stepping. | |
442 | */ | |
443 | if (!alt || predicate(insn) != PREDICATE_ALWAYS) | |
444 | add_breakpoint(child, dbg, pc + 4); | |
445 | } | |
446 | } | |
447 | ||
448 | /* | |
449 | * Ensure no single-step breakpoint is pending. Returns non-zero | |
450 | * value if child was being single-stepped. | |
451 | */ | |
452 | void ptrace_cancel_bpt(struct task_struct *child) | |
453 | { | |
454 | int i, nsaved = child->thread.debug.nsaved; | |
455 | ||
456 | child->thread.debug.nsaved = 0; | |
457 | ||
458 | if (nsaved > 2) { | |
459 | printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved); | |
460 | nsaved = 2; | |
461 | } | |
462 | ||
463 | for (i = 0; i < nsaved; i++) | |
464 | clear_breakpoint(child, &child->thread.debug.bp[i]); | |
465 | } | |
466 | ||
467 | /* | |
468 | * Called by kernel/ptrace.c when detaching.. | |
469 | * | |
470 | * Make sure the single step bit is not set. | |
471 | */ | |
472 | void ptrace_disable(struct task_struct *child) | |
473 | { | |
474 | child->ptrace &= ~PT_SINGLESTEP; | |
475 | ptrace_cancel_bpt(child); | |
476 | } | |
477 | ||
478 | /* | |
479 | * Handle hitting a breakpoint. | |
480 | */ | |
481 | void ptrace_break(struct task_struct *tsk, struct pt_regs *regs) | |
482 | { | |
483 | siginfo_t info; | |
484 | ||
485 | ptrace_cancel_bpt(tsk); | |
486 | ||
487 | info.si_signo = SIGTRAP; | |
488 | info.si_errno = 0; | |
489 | info.si_code = TRAP_BRKPT; | |
490 | info.si_addr = (void __user *)instruction_pointer(regs); | |
491 | ||
492 | force_sig_info(SIGTRAP, &info, tsk); | |
493 | } | |
494 | ||
495 | static int break_trap(struct pt_regs *regs, unsigned int instr) | |
496 | { | |
497 | ptrace_break(current, regs); | |
498 | return 0; | |
499 | } | |
500 | ||
501 | static struct undef_hook arm_break_hook = { | |
502 | .instr_mask = 0x0fffffff, | |
503 | .instr_val = 0x07f001f0, | |
504 | .cpsr_mask = PSR_T_BIT, | |
505 | .cpsr_val = 0, | |
506 | .fn = break_trap, | |
507 | }; | |
508 | ||
509 | static struct undef_hook thumb_break_hook = { | |
510 | .instr_mask = 0xffff, | |
511 | .instr_val = 0xde01, | |
512 | .cpsr_mask = PSR_T_BIT, | |
513 | .cpsr_val = PSR_T_BIT, | |
514 | .fn = break_trap, | |
515 | }; | |
516 | ||
517 | static int __init ptrace_break_init(void) | |
518 | { | |
519 | register_undef_hook(&arm_break_hook); | |
520 | register_undef_hook(&thumb_break_hook); | |
521 | return 0; | |
522 | } | |
523 | ||
524 | core_initcall(ptrace_break_init); | |
525 | ||
526 | /* | |
527 | * Read the word at offset "off" into the "struct user". We | |
528 | * actually access the pt_regs stored on the kernel stack. | |
529 | */ | |
530 | static int ptrace_read_user(struct task_struct *tsk, unsigned long off, | |
531 | unsigned long __user *ret) | |
532 | { | |
533 | unsigned long tmp; | |
534 | ||
535 | if (off & 3 || off >= sizeof(struct user)) | |
536 | return -EIO; | |
537 | ||
538 | tmp = 0; | |
539 | if (off < sizeof(struct pt_regs)) | |
540 | tmp = get_user_reg(tsk, off >> 2); | |
541 | ||
542 | return put_user(tmp, ret); | |
543 | } | |
544 | ||
545 | /* | |
546 | * Write the word at offset "off" into "struct user". We | |
547 | * actually access the pt_regs stored on the kernel stack. | |
548 | */ | |
549 | static int ptrace_write_user(struct task_struct *tsk, unsigned long off, | |
550 | unsigned long val) | |
551 | { | |
552 | if (off & 3 || off >= sizeof(struct user)) | |
553 | return -EIO; | |
554 | ||
555 | if (off >= sizeof(struct pt_regs)) | |
556 | return 0; | |
557 | ||
558 | return put_user_reg(tsk, off >> 2, val); | |
559 | } | |
560 | ||
561 | /* | |
562 | * Get all user integer registers. | |
563 | */ | |
564 | static int ptrace_getregs(struct task_struct *tsk, void __user *uregs) | |
565 | { | |
566 | struct pt_regs *regs = get_user_regs(tsk); | |
567 | ||
568 | return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0; | |
569 | } | |
570 | ||
571 | /* | |
572 | * Set all user integer registers. | |
573 | */ | |
574 | static int ptrace_setregs(struct task_struct *tsk, void __user *uregs) | |
575 | { | |
576 | struct pt_regs newregs; | |
577 | int ret; | |
578 | ||
579 | ret = -EFAULT; | |
580 | if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) { | |
581 | struct pt_regs *regs = get_user_regs(tsk); | |
582 | ||
583 | ret = -EINVAL; | |
584 | if (valid_user_regs(&newregs)) { | |
585 | *regs = newregs; | |
586 | ret = 0; | |
587 | } | |
588 | } | |
589 | ||
590 | return ret; | |
591 | } | |
592 | ||
593 | /* | |
594 | * Get the child FPU state. | |
595 | */ | |
596 | static int ptrace_getfpregs(struct task_struct *tsk, void __user *ufp) | |
597 | { | |
598 | return copy_to_user(ufp, &tsk->thread_info->fpstate, | |
599 | sizeof(struct user_fp)) ? -EFAULT : 0; | |
600 | } | |
601 | ||
602 | /* | |
603 | * Set the child FPU state. | |
604 | */ | |
605 | static int ptrace_setfpregs(struct task_struct *tsk, void __user *ufp) | |
606 | { | |
607 | struct thread_info *thread = tsk->thread_info; | |
608 | thread->used_cp[1] = thread->used_cp[2] = 1; | |
609 | return copy_from_user(&thread->fpstate, ufp, | |
610 | sizeof(struct user_fp)) ? -EFAULT : 0; | |
611 | } | |
612 | ||
613 | #ifdef CONFIG_IWMMXT | |
614 | ||
615 | /* | |
616 | * Get the child iWMMXt state. | |
617 | */ | |
618 | static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp) | |
619 | { | |
620 | struct thread_info *thread = tsk->thread_info; | |
621 | void *ptr = &thread->fpstate; | |
622 | ||
623 | if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) | |
624 | return -ENODATA; | |
625 | iwmmxt_task_disable(thread); /* force it to ram */ | |
626 | /* The iWMMXt state is stored doubleword-aligned. */ | |
627 | if (((long) ptr) & 4) | |
628 | ptr += 4; | |
629 | return copy_to_user(ufp, ptr, 0x98) ? -EFAULT : 0; | |
630 | } | |
631 | ||
632 | /* | |
633 | * Set the child iWMMXt state. | |
634 | */ | |
635 | static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp) | |
636 | { | |
637 | struct thread_info *thread = tsk->thread_info; | |
638 | void *ptr = &thread->fpstate; | |
639 | ||
640 | if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) | |
641 | return -EACCES; | |
642 | iwmmxt_task_release(thread); /* force a reload */ | |
643 | /* The iWMMXt state is stored doubleword-aligned. */ | |
644 | if (((long) ptr) & 4) | |
645 | ptr += 4; | |
646 | return copy_from_user(ptr, ufp, 0x98) ? -EFAULT : 0; | |
647 | } | |
648 | ||
649 | #endif | |
650 | ||
651 | static int do_ptrace(int request, struct task_struct *child, long addr, long data) | |
652 | { | |
653 | unsigned long tmp; | |
654 | int ret; | |
655 | ||
656 | switch (request) { | |
657 | /* | |
658 | * read word at location "addr" in the child process. | |
659 | */ | |
660 | case PTRACE_PEEKTEXT: | |
661 | case PTRACE_PEEKDATA: | |
662 | ret = access_process_vm(child, addr, &tmp, | |
663 | sizeof(unsigned long), 0); | |
664 | if (ret == sizeof(unsigned long)) | |
665 | ret = put_user(tmp, (unsigned long __user *) data); | |
666 | else | |
667 | ret = -EIO; | |
668 | break; | |
669 | ||
670 | case PTRACE_PEEKUSR: | |
671 | ret = ptrace_read_user(child, addr, (unsigned long __user *)data); | |
672 | break; | |
673 | ||
674 | /* | |
675 | * write the word at location addr. | |
676 | */ | |
677 | case PTRACE_POKETEXT: | |
678 | case PTRACE_POKEDATA: | |
679 | ret = access_process_vm(child, addr, &data, | |
680 | sizeof(unsigned long), 1); | |
681 | if (ret == sizeof(unsigned long)) | |
682 | ret = 0; | |
683 | else | |
684 | ret = -EIO; | |
685 | break; | |
686 | ||
687 | case PTRACE_POKEUSR: | |
688 | ret = ptrace_write_user(child, addr, data); | |
689 | break; | |
690 | ||
691 | /* | |
692 | * continue/restart and stop at next (return from) syscall | |
693 | */ | |
694 | case PTRACE_SYSCALL: | |
695 | case PTRACE_CONT: | |
696 | ret = -EIO; | |
7ed20e1a | 697 | if (!valid_signal(data)) |
1da177e4 LT |
698 | break; |
699 | if (request == PTRACE_SYSCALL) | |
700 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
701 | else | |
702 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
703 | child->exit_code = data; | |
704 | /* make sure single-step breakpoint is gone. */ | |
705 | child->ptrace &= ~PT_SINGLESTEP; | |
706 | ptrace_cancel_bpt(child); | |
707 | wake_up_process(child); | |
708 | ret = 0; | |
709 | break; | |
710 | ||
711 | /* | |
712 | * make the child exit. Best I can do is send it a sigkill. | |
713 | * perhaps it should be put in the status that it wants to | |
714 | * exit. | |
715 | */ | |
716 | case PTRACE_KILL: | |
717 | /* make sure single-step breakpoint is gone. */ | |
718 | child->ptrace &= ~PT_SINGLESTEP; | |
719 | ptrace_cancel_bpt(child); | |
720 | if (child->exit_state != EXIT_ZOMBIE) { | |
721 | child->exit_code = SIGKILL; | |
722 | wake_up_process(child); | |
723 | } | |
724 | ret = 0; | |
725 | break; | |
726 | ||
727 | /* | |
728 | * execute single instruction. | |
729 | */ | |
730 | case PTRACE_SINGLESTEP: | |
731 | ret = -EIO; | |
7ed20e1a | 732 | if (!valid_signal(data)) |
1da177e4 LT |
733 | break; |
734 | child->ptrace |= PT_SINGLESTEP; | |
735 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
736 | child->exit_code = data; | |
737 | /* give it a chance to run. */ | |
738 | wake_up_process(child); | |
739 | ret = 0; | |
740 | break; | |
741 | ||
742 | case PTRACE_DETACH: | |
743 | ret = ptrace_detach(child, data); | |
744 | break; | |
745 | ||
746 | case PTRACE_GETREGS: | |
747 | ret = ptrace_getregs(child, (void __user *)data); | |
748 | break; | |
749 | ||
750 | case PTRACE_SETREGS: | |
751 | ret = ptrace_setregs(child, (void __user *)data); | |
752 | break; | |
753 | ||
754 | case PTRACE_GETFPREGS: | |
755 | ret = ptrace_getfpregs(child, (void __user *)data); | |
756 | break; | |
757 | ||
758 | case PTRACE_SETFPREGS: | |
759 | ret = ptrace_setfpregs(child, (void __user *)data); | |
760 | break; | |
761 | ||
762 | #ifdef CONFIG_IWMMXT | |
763 | case PTRACE_GETWMMXREGS: | |
764 | ret = ptrace_getwmmxregs(child, (void __user *)data); | |
765 | break; | |
766 | ||
767 | case PTRACE_SETWMMXREGS: | |
768 | ret = ptrace_setwmmxregs(child, (void __user *)data); | |
769 | break; | |
770 | #endif | |
771 | ||
772 | case PTRACE_GET_THREAD_AREA: | |
773 | ret = put_user(child->thread_info->tp_value, | |
774 | (unsigned long __user *) data); | |
775 | break; | |
776 | ||
777 | default: | |
778 | ret = ptrace_request(child, request, addr, data); | |
779 | break; | |
780 | } | |
781 | ||
782 | return ret; | |
783 | } | |
784 | ||
785 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
786 | { | |
787 | struct task_struct *child; | |
788 | int ret; | |
789 | ||
790 | lock_kernel(); | |
791 | ret = -EPERM; | |
792 | if (request == PTRACE_TRACEME) { | |
793 | /* are we already being traced? */ | |
794 | if (current->ptrace & PT_PTRACED) | |
795 | goto out; | |
796 | ret = security_ptrace(current->parent, current); | |
797 | if (ret) | |
798 | goto out; | |
799 | /* set the ptrace bit in the process flags. */ | |
800 | current->ptrace |= PT_PTRACED; | |
801 | ret = 0; | |
802 | goto out; | |
803 | } | |
804 | ret = -ESRCH; | |
805 | read_lock(&tasklist_lock); | |
806 | child = find_task_by_pid(pid); | |
807 | if (child) | |
808 | get_task_struct(child); | |
809 | read_unlock(&tasklist_lock); | |
810 | if (!child) | |
811 | goto out; | |
812 | ||
813 | ret = -EPERM; | |
814 | if (pid == 1) /* you may not mess with init */ | |
815 | goto out_tsk; | |
816 | ||
817 | if (request == PTRACE_ATTACH) { | |
818 | ret = ptrace_attach(child); | |
819 | goto out_tsk; | |
820 | } | |
821 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
822 | if (ret == 0) | |
823 | ret = do_ptrace(request, child, addr, data); | |
824 | ||
825 | out_tsk: | |
826 | put_task_struct(child); | |
827 | out: | |
828 | unlock_kernel(); | |
829 | return ret; | |
830 | } | |
831 | ||
832 | asmlinkage void syscall_trace(int why, struct pt_regs *regs) | |
833 | { | |
834 | unsigned long ip; | |
835 | ||
836 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
837 | return; | |
838 | if (!(current->ptrace & PT_PTRACED)) | |
839 | return; | |
840 | ||
841 | /* | |
842 | * Save IP. IP is used to denote syscall entry/exit: | |
843 | * IP = 0 -> entry, = 1 -> exit | |
844 | */ | |
845 | ip = regs->ARM_ip; | |
846 | regs->ARM_ip = why; | |
847 | ||
848 | /* the 0x80 provides a way for the tracing parent to distinguish | |
849 | between a syscall stop and SIGTRAP delivery */ | |
850 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
851 | ? 0x80 : 0)); | |
852 | /* | |
853 | * this isn't the same as continuing with a signal, but it will do | |
854 | * for normal use. strace only continues with a signal if the | |
855 | * stopping signal is not SIGTRAP. -brl | |
856 | */ | |
857 | if (current->exit_code) { | |
858 | send_sig(current->exit_code, current, 1); | |
859 | current->exit_code = 0; | |
860 | } | |
861 | regs->ARM_ip = ip; | |
862 | } |