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Commit | Line | Data |
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1da177e4 LT |
1 | /* ptrace.c */ |
2 | /* By Ross Biro 1/23/92 */ | |
3 | /* | |
4 | * Pentium III FXSR, SSE support | |
5 | * Gareth Hughes <gareth@valinux.com>, May 2000 | |
6 | */ | |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/sched.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/smp.h> | |
12 | #include <linux/smp_lock.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/user.h> | |
16 | #include <linux/security.h> | |
17 | #include <linux/audit.h> | |
18 | #include <linux/seccomp.h> | |
19 | ||
20 | #include <asm/uaccess.h> | |
21 | #include <asm/pgtable.h> | |
22 | #include <asm/system.h> | |
23 | #include <asm/processor.h> | |
24 | #include <asm/i387.h> | |
25 | #include <asm/debugreg.h> | |
26 | #include <asm/ldt.h> | |
27 | #include <asm/desc.h> | |
28 | ||
29 | /* | |
30 | * does not yet catch signals sent when the child dies. | |
31 | * in exit.c or in signal.c. | |
32 | */ | |
33 | ||
34 | /* determines which flags the user has access to. */ | |
35 | /* 1 = access 0 = no access */ | |
36 | #define FLAG_MASK 0x00044dd5 | |
37 | ||
38 | /* set's the trap flag. */ | |
39 | #define TRAP_FLAG 0x100 | |
40 | ||
41 | /* | |
42 | * Offset of eflags on child stack.. | |
43 | */ | |
44 | #define EFL_OFFSET ((EFL-2)*4-sizeof(struct pt_regs)) | |
45 | ||
46 | static inline struct pt_regs *get_child_regs(struct task_struct *task) | |
47 | { | |
48 | void *stack_top = (void *)task->thread.esp0; | |
49 | return stack_top - sizeof(struct pt_regs); | |
50 | } | |
51 | ||
52 | /* | |
53 | * this routine will get a word off of the processes privileged stack. | |
54 | * the offset is how far from the base addr as stored in the TSS. | |
55 | * this routine assumes that all the privileged stacks are in our | |
56 | * data space. | |
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.esp0; | |
63 | stack += offset; | |
64 | return (*((int *)stack)); | |
65 | } | |
66 | ||
67 | /* | |
68 | * this routine will put a word on the processes privileged stack. | |
69 | * the offset is how far from the base addr as stored in the TSS. | |
70 | * this routine assumes that all the privileged stacks are in our | |
71 | * data space. | |
72 | */ | |
73 | static inline int put_stack_long(struct task_struct *task, int offset, | |
74 | unsigned long data) | |
75 | { | |
76 | unsigned char * stack; | |
77 | ||
78 | stack = (unsigned char *) task->thread.esp0; | |
79 | stack += offset; | |
80 | *(unsigned long *) stack = data; | |
81 | return 0; | |
82 | } | |
83 | ||
84 | static int putreg(struct task_struct *child, | |
85 | unsigned long regno, unsigned long value) | |
86 | { | |
87 | switch (regno >> 2) { | |
88 | case FS: | |
89 | if (value && (value & 3) != 3) | |
90 | return -EIO; | |
91 | child->thread.fs = value; | |
92 | return 0; | |
93 | case GS: | |
94 | if (value && (value & 3) != 3) | |
95 | return -EIO; | |
96 | child->thread.gs = value; | |
97 | return 0; | |
98 | case DS: | |
99 | case ES: | |
100 | if (value && (value & 3) != 3) | |
101 | return -EIO; | |
102 | value &= 0xffff; | |
103 | break; | |
104 | case SS: | |
105 | case CS: | |
106 | if ((value & 3) != 3) | |
107 | return -EIO; | |
108 | value &= 0xffff; | |
109 | break; | |
110 | case EFL: | |
111 | value &= FLAG_MASK; | |
112 | value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK; | |
113 | break; | |
114 | } | |
115 | if (regno > GS*4) | |
116 | regno -= 2*4; | |
117 | put_stack_long(child, regno - sizeof(struct pt_regs), value); | |
118 | return 0; | |
119 | } | |
120 | ||
121 | static unsigned long getreg(struct task_struct *child, | |
122 | unsigned long regno) | |
123 | { | |
124 | unsigned long retval = ~0UL; | |
125 | ||
126 | switch (regno >> 2) { | |
127 | case FS: | |
128 | retval = child->thread.fs; | |
129 | break; | |
130 | case GS: | |
131 | retval = child->thread.gs; | |
132 | break; | |
133 | case DS: | |
134 | case ES: | |
135 | case SS: | |
136 | case CS: | |
137 | retval = 0xffff; | |
138 | /* fall through */ | |
139 | default: | |
140 | if (regno > GS*4) | |
141 | regno -= 2*4; | |
142 | regno = regno - sizeof(struct pt_regs); | |
143 | retval &= get_stack_long(child, regno); | |
144 | } | |
145 | return retval; | |
146 | } | |
147 | ||
148 | #define LDT_SEGMENT 4 | |
149 | ||
150 | static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs) | |
151 | { | |
152 | unsigned long addr, seg; | |
153 | ||
154 | addr = regs->eip; | |
155 | seg = regs->xcs & 0xffff; | |
156 | if (regs->eflags & VM_MASK) { | |
157 | addr = (addr & 0xffff) + (seg << 4); | |
158 | return addr; | |
159 | } | |
160 | ||
161 | /* | |
162 | * We'll assume that the code segments in the GDT | |
163 | * are all zero-based. That is largely true: the | |
164 | * TLS segments are used for data, and the PNPBIOS | |
165 | * and APM bios ones we just ignore here. | |
166 | */ | |
167 | if (seg & LDT_SEGMENT) { | |
168 | u32 *desc; | |
169 | unsigned long base; | |
170 | ||
171 | down(&child->mm->context.sem); | |
172 | desc = child->mm->context.ldt + (seg & ~7); | |
173 | base = (desc[0] >> 16) | ((desc[1] & 0xff) << 16) | (desc[1] & 0xff000000); | |
174 | ||
175 | /* 16-bit code segment? */ | |
176 | if (!((desc[1] >> 22) & 1)) | |
177 | addr &= 0xffff; | |
178 | addr += base; | |
179 | up(&child->mm->context.sem); | |
180 | } | |
181 | return addr; | |
182 | } | |
183 | ||
184 | static inline int is_at_popf(struct task_struct *child, struct pt_regs *regs) | |
185 | { | |
186 | int i, copied; | |
187 | unsigned char opcode[16]; | |
188 | unsigned long addr = convert_eip_to_linear(child, regs); | |
189 | ||
190 | copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0); | |
191 | for (i = 0; i < copied; i++) { | |
192 | switch (opcode[i]) { | |
193 | /* popf */ | |
194 | case 0x9d: | |
195 | return 1; | |
196 | /* opcode and address size prefixes */ | |
197 | case 0x66: case 0x67: | |
198 | continue; | |
199 | /* irrelevant prefixes (segment overrides and repeats) */ | |
200 | case 0x26: case 0x2e: | |
201 | case 0x36: case 0x3e: | |
202 | case 0x64: case 0x65: | |
203 | case 0xf0: case 0xf2: case 0xf3: | |
204 | continue; | |
205 | ||
206 | /* | |
207 | * pushf: NOTE! We should probably not let | |
208 | * the user see the TF bit being set. But | |
209 | * it's more pain than it's worth to avoid | |
210 | * it, and a debugger could emulate this | |
211 | * all in user space if it _really_ cares. | |
212 | */ | |
213 | case 0x9c: | |
214 | default: | |
215 | return 0; | |
216 | } | |
217 | } | |
218 | return 0; | |
219 | } | |
220 | ||
221 | static void set_singlestep(struct task_struct *child) | |
222 | { | |
223 | struct pt_regs *regs = get_child_regs(child); | |
224 | ||
225 | /* | |
226 | * Always set TIF_SINGLESTEP - this guarantees that | |
227 | * we single-step system calls etc.. This will also | |
228 | * cause us to set TF when returning to user mode. | |
229 | */ | |
230 | set_tsk_thread_flag(child, TIF_SINGLESTEP); | |
231 | ||
232 | /* | |
233 | * If TF was already set, don't do anything else | |
234 | */ | |
235 | if (regs->eflags & TRAP_FLAG) | |
236 | return; | |
237 | ||
238 | /* Set TF on the kernel stack.. */ | |
239 | regs->eflags |= TRAP_FLAG; | |
240 | ||
241 | /* | |
242 | * ..but if TF is changed by the instruction we will trace, | |
243 | * don't mark it as being "us" that set it, so that we | |
244 | * won't clear it by hand later. | |
245 | */ | |
246 | if (is_at_popf(child, regs)) | |
247 | return; | |
248 | ||
249 | child->ptrace |= PT_DTRACE; | |
250 | } | |
251 | ||
252 | static void clear_singlestep(struct task_struct *child) | |
253 | { | |
254 | /* Always clear TIF_SINGLESTEP... */ | |
255 | clear_tsk_thread_flag(child, TIF_SINGLESTEP); | |
256 | ||
257 | /* But touch TF only if it was set by us.. */ | |
258 | if (child->ptrace & PT_DTRACE) { | |
259 | struct pt_regs *regs = get_child_regs(child); | |
260 | regs->eflags &= ~TRAP_FLAG; | |
261 | child->ptrace &= ~PT_DTRACE; | |
262 | } | |
263 | } | |
264 | ||
265 | /* | |
266 | * Called by kernel/ptrace.c when detaching.. | |
267 | * | |
268 | * Make sure the single step bit is not set. | |
269 | */ | |
270 | void ptrace_disable(struct task_struct *child) | |
271 | { | |
272 | clear_singlestep(child); | |
273 | } | |
274 | ||
275 | /* | |
276 | * Perform get_thread_area on behalf of the traced child. | |
277 | */ | |
278 | static int | |
279 | ptrace_get_thread_area(struct task_struct *child, | |
280 | int idx, struct user_desc __user *user_desc) | |
281 | { | |
282 | struct user_desc info; | |
283 | struct desc_struct *desc; | |
284 | ||
285 | /* | |
286 | * Get the current Thread-Local Storage area: | |
287 | */ | |
288 | ||
289 | #define GET_BASE(desc) ( \ | |
290 | (((desc)->a >> 16) & 0x0000ffff) | \ | |
291 | (((desc)->b << 16) & 0x00ff0000) | \ | |
292 | ( (desc)->b & 0xff000000) ) | |
293 | ||
294 | #define GET_LIMIT(desc) ( \ | |
295 | ((desc)->a & 0x0ffff) | \ | |
296 | ((desc)->b & 0xf0000) ) | |
297 | ||
298 | #define GET_32BIT(desc) (((desc)->b >> 22) & 1) | |
299 | #define GET_CONTENTS(desc) (((desc)->b >> 10) & 3) | |
300 | #define GET_WRITABLE(desc) (((desc)->b >> 9) & 1) | |
301 | #define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1) | |
302 | #define GET_PRESENT(desc) (((desc)->b >> 15) & 1) | |
303 | #define GET_USEABLE(desc) (((desc)->b >> 20) & 1) | |
304 | ||
305 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) | |
306 | return -EINVAL; | |
307 | ||
308 | desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; | |
309 | ||
310 | info.entry_number = idx; | |
311 | info.base_addr = GET_BASE(desc); | |
312 | info.limit = GET_LIMIT(desc); | |
313 | info.seg_32bit = GET_32BIT(desc); | |
314 | info.contents = GET_CONTENTS(desc); | |
315 | info.read_exec_only = !GET_WRITABLE(desc); | |
316 | info.limit_in_pages = GET_LIMIT_PAGES(desc); | |
317 | info.seg_not_present = !GET_PRESENT(desc); | |
318 | info.useable = GET_USEABLE(desc); | |
319 | ||
320 | if (copy_to_user(user_desc, &info, sizeof(info))) | |
321 | return -EFAULT; | |
322 | ||
323 | return 0; | |
324 | } | |
325 | ||
326 | /* | |
327 | * Perform set_thread_area on behalf of the traced child. | |
328 | */ | |
329 | static int | |
330 | ptrace_set_thread_area(struct task_struct *child, | |
331 | int idx, struct user_desc __user *user_desc) | |
332 | { | |
333 | struct user_desc info; | |
334 | struct desc_struct *desc; | |
335 | ||
336 | if (copy_from_user(&info, user_desc, sizeof(info))) | |
337 | return -EFAULT; | |
338 | ||
339 | if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) | |
340 | return -EINVAL; | |
341 | ||
342 | desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; | |
343 | if (LDT_empty(&info)) { | |
344 | desc->a = 0; | |
345 | desc->b = 0; | |
346 | } else { | |
347 | desc->a = LDT_entry_a(&info); | |
348 | desc->b = LDT_entry_b(&info); | |
349 | } | |
350 | ||
351 | return 0; | |
352 | } | |
353 | ||
354 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
355 | { | |
356 | struct task_struct *child; | |
357 | struct user * dummy = NULL; | |
358 | int i, ret; | |
359 | unsigned long __user *datap = (unsigned long __user *)data; | |
360 | ||
361 | lock_kernel(); | |
362 | ret = -EPERM; | |
363 | if (request == PTRACE_TRACEME) { | |
364 | /* are we already being traced? */ | |
365 | if (current->ptrace & PT_PTRACED) | |
366 | goto out; | |
367 | ret = security_ptrace(current->parent, current); | |
368 | if (ret) | |
369 | goto out; | |
370 | /* set the ptrace bit in the process flags. */ | |
371 | current->ptrace |= PT_PTRACED; | |
372 | ret = 0; | |
373 | goto out; | |
374 | } | |
375 | ret = -ESRCH; | |
376 | read_lock(&tasklist_lock); | |
377 | child = find_task_by_pid(pid); | |
378 | if (child) | |
379 | get_task_struct(child); | |
380 | read_unlock(&tasklist_lock); | |
381 | if (!child) | |
382 | goto out; | |
383 | ||
384 | ret = -EPERM; | |
385 | if (pid == 1) /* you may not mess with init */ | |
386 | goto out_tsk; | |
387 | ||
388 | if (request == PTRACE_ATTACH) { | |
389 | ret = ptrace_attach(child); | |
390 | goto out_tsk; | |
391 | } | |
392 | ||
393 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
394 | if (ret < 0) | |
395 | goto out_tsk; | |
396 | ||
397 | switch (request) { | |
398 | /* when I and D space are separate, these will need to be fixed. */ | |
399 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
400 | case PTRACE_PEEKDATA: { | |
401 | unsigned long tmp; | |
402 | int copied; | |
403 | ||
404 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
405 | ret = -EIO; | |
406 | if (copied != sizeof(tmp)) | |
407 | break; | |
408 | ret = put_user(tmp, datap); | |
409 | break; | |
410 | } | |
411 | ||
412 | /* read the word at location addr in the USER area. */ | |
413 | case PTRACE_PEEKUSR: { | |
414 | unsigned long tmp; | |
415 | ||
416 | ret = -EIO; | |
417 | if ((addr & 3) || addr < 0 || | |
418 | addr > sizeof(struct user) - 3) | |
419 | break; | |
420 | ||
421 | tmp = 0; /* Default return condition */ | |
422 | if(addr < FRAME_SIZE*sizeof(long)) | |
423 | tmp = getreg(child, addr); | |
424 | if(addr >= (long) &dummy->u_debugreg[0] && | |
425 | addr <= (long) &dummy->u_debugreg[7]){ | |
426 | addr -= (long) &dummy->u_debugreg[0]; | |
427 | addr = addr >> 2; | |
428 | tmp = child->thread.debugreg[addr]; | |
429 | } | |
430 | ret = put_user(tmp, datap); | |
431 | break; | |
432 | } | |
433 | ||
434 | /* when I and D space are separate, this will have to be fixed. */ | |
435 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
436 | case PTRACE_POKEDATA: | |
437 | ret = 0; | |
438 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
439 | break; | |
440 | ret = -EIO; | |
441 | break; | |
442 | ||
443 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ | |
444 | ret = -EIO; | |
445 | if ((addr & 3) || addr < 0 || | |
446 | addr > sizeof(struct user) - 3) | |
447 | break; | |
448 | ||
449 | if (addr < FRAME_SIZE*sizeof(long)) { | |
450 | ret = putreg(child, addr, data); | |
451 | break; | |
452 | } | |
453 | /* We need to be very careful here. We implicitly | |
454 | want to modify a portion of the task_struct, and we | |
455 | have to be selective about what portions we allow someone | |
456 | to modify. */ | |
457 | ||
458 | ret = -EIO; | |
459 | if(addr >= (long) &dummy->u_debugreg[0] && | |
460 | addr <= (long) &dummy->u_debugreg[7]){ | |
461 | ||
462 | if(addr == (long) &dummy->u_debugreg[4]) break; | |
463 | if(addr == (long) &dummy->u_debugreg[5]) break; | |
464 | if(addr < (long) &dummy->u_debugreg[4] && | |
465 | ((unsigned long) data) >= TASK_SIZE-3) break; | |
466 | ||
467 | /* Sanity-check data. Take one half-byte at once with | |
468 | * check = (val >> (16 + 4*i)) & 0xf. It contains the | |
469 | * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits | |
470 | * 2 and 3 are LENi. Given a list of invalid values, | |
471 | * we do mask |= 1 << invalid_value, so that | |
472 | * (mask >> check) & 1 is a correct test for invalid | |
473 | * values. | |
474 | * | |
475 | * R/Wi contains the type of the breakpoint / | |
476 | * watchpoint, LENi contains the length of the watched | |
477 | * data in the watchpoint case. | |
478 | * | |
479 | * The invalid values are: | |
480 | * - LENi == 0x10 (undefined), so mask |= 0x0f00. | |
481 | * - R/Wi == 0x10 (break on I/O reads or writes), so | |
482 | * mask |= 0x4444. | |
483 | * - R/Wi == 0x00 && LENi != 0x00, so we have mask |= | |
484 | * 0x1110. | |
485 | * | |
486 | * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54. | |
487 | * | |
488 | * See the Intel Manual "System Programming Guide", | |
489 | * 15.2.4 | |
490 | * | |
491 | * Note that LENi == 0x10 is defined on x86_64 in long | |
492 | * mode (i.e. even for 32-bit userspace software, but | |
493 | * 64-bit kernel), so the x86_64 mask value is 0x5454. | |
494 | * See the AMD manual no. 24593 (AMD64 System | |
495 | * Programming)*/ | |
496 | ||
497 | if(addr == (long) &dummy->u_debugreg[7]) { | |
498 | data &= ~DR_CONTROL_RESERVED; | |
499 | for(i=0; i<4; i++) | |
500 | if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1) | |
501 | goto out_tsk; | |
502 | } | |
503 | ||
504 | addr -= (long) &dummy->u_debugreg; | |
505 | addr = addr >> 2; | |
506 | child->thread.debugreg[addr] = data; | |
507 | ret = 0; | |
508 | } | |
509 | break; | |
510 | ||
511 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
512 | case PTRACE_CONT: /* restart after signal. */ | |
513 | ret = -EIO; | |
514 | if ((unsigned long) data > _NSIG) | |
515 | break; | |
516 | if (request == PTRACE_SYSCALL) { | |
517 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
518 | } | |
519 | else { | |
520 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
521 | } | |
522 | child->exit_code = data; | |
523 | /* make sure the single step bit is not set. */ | |
524 | clear_singlestep(child); | |
525 | wake_up_process(child); | |
526 | ret = 0; | |
527 | break; | |
528 | ||
529 | /* | |
530 | * make the child exit. Best I can do is send it a sigkill. | |
531 | * perhaps it should be put in the status that it wants to | |
532 | * exit. | |
533 | */ | |
534 | case PTRACE_KILL: | |
535 | ret = 0; | |
536 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
537 | break; | |
538 | child->exit_code = SIGKILL; | |
539 | /* make sure the single step bit is not set. */ | |
540 | clear_singlestep(child); | |
541 | wake_up_process(child); | |
542 | break; | |
543 | ||
544 | case PTRACE_SINGLESTEP: /* set the trap flag. */ | |
545 | ret = -EIO; | |
546 | if ((unsigned long) data > _NSIG) | |
547 | break; | |
548 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
549 | set_singlestep(child); | |
550 | child->exit_code = data; | |
551 | /* give it a chance to run. */ | |
552 | wake_up_process(child); | |
553 | ret = 0; | |
554 | break; | |
555 | ||
556 | case PTRACE_DETACH: | |
557 | /* detach a process that was attached. */ | |
558 | ret = ptrace_detach(child, data); | |
559 | break; | |
560 | ||
561 | case PTRACE_GETREGS: { /* Get all gp regs from the child. */ | |
562 | if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) { | |
563 | ret = -EIO; | |
564 | break; | |
565 | } | |
566 | for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) { | |
567 | __put_user(getreg(child, i), datap); | |
568 | datap++; | |
569 | } | |
570 | ret = 0; | |
571 | break; | |
572 | } | |
573 | ||
574 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ | |
575 | unsigned long tmp; | |
576 | if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) { | |
577 | ret = -EIO; | |
578 | break; | |
579 | } | |
580 | for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) { | |
581 | __get_user(tmp, datap); | |
582 | putreg(child, i, tmp); | |
583 | datap++; | |
584 | } | |
585 | ret = 0; | |
586 | break; | |
587 | } | |
588 | ||
589 | case PTRACE_GETFPREGS: { /* Get the child FPU state. */ | |
590 | if (!access_ok(VERIFY_WRITE, datap, | |
591 | sizeof(struct user_i387_struct))) { | |
592 | ret = -EIO; | |
593 | break; | |
594 | } | |
595 | ret = 0; | |
596 | if (!tsk_used_math(child)) | |
597 | init_fpu(child); | |
598 | get_fpregs((struct user_i387_struct __user *)data, child); | |
599 | break; | |
600 | } | |
601 | ||
602 | case PTRACE_SETFPREGS: { /* Set the child FPU state. */ | |
603 | if (!access_ok(VERIFY_READ, datap, | |
604 | sizeof(struct user_i387_struct))) { | |
605 | ret = -EIO; | |
606 | break; | |
607 | } | |
608 | set_stopped_child_used_math(child); | |
609 | set_fpregs(child, (struct user_i387_struct __user *)data); | |
610 | ret = 0; | |
611 | break; | |
612 | } | |
613 | ||
614 | case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */ | |
615 | if (!access_ok(VERIFY_WRITE, datap, | |
616 | sizeof(struct user_fxsr_struct))) { | |
617 | ret = -EIO; | |
618 | break; | |
619 | } | |
620 | if (!tsk_used_math(child)) | |
621 | init_fpu(child); | |
622 | ret = get_fpxregs((struct user_fxsr_struct __user *)data, child); | |
623 | break; | |
624 | } | |
625 | ||
626 | case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */ | |
627 | if (!access_ok(VERIFY_READ, datap, | |
628 | sizeof(struct user_fxsr_struct))) { | |
629 | ret = -EIO; | |
630 | break; | |
631 | } | |
632 | set_stopped_child_used_math(child); | |
633 | ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data); | |
634 | break; | |
635 | } | |
636 | ||
637 | case PTRACE_GET_THREAD_AREA: | |
638 | ret = ptrace_get_thread_area(child, addr, | |
639 | (struct user_desc __user *) data); | |
640 | break; | |
641 | ||
642 | case PTRACE_SET_THREAD_AREA: | |
643 | ret = ptrace_set_thread_area(child, addr, | |
644 | (struct user_desc __user *) data); | |
645 | break; | |
646 | ||
647 | default: | |
648 | ret = ptrace_request(child, request, addr, data); | |
649 | break; | |
650 | } | |
651 | out_tsk: | |
652 | put_task_struct(child); | |
653 | out: | |
654 | unlock_kernel(); | |
655 | return ret; | |
656 | } | |
657 | ||
658 | void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) | |
659 | { | |
660 | struct siginfo info; | |
661 | ||
662 | tsk->thread.trap_no = 1; | |
663 | tsk->thread.error_code = error_code; | |
664 | ||
665 | memset(&info, 0, sizeof(info)); | |
666 | info.si_signo = SIGTRAP; | |
667 | info.si_code = TRAP_BRKPT; | |
668 | ||
669 | /* User-mode eip? */ | |
670 | info.si_addr = user_mode(regs) ? (void __user *) regs->eip : NULL; | |
671 | ||
672 | /* Send us the fakey SIGTRAP */ | |
673 | force_sig_info(SIGTRAP, &info, tsk); | |
674 | } | |
675 | ||
676 | /* notification of system call entry/exit | |
677 | * - triggered by current->work.syscall_trace | |
678 | */ | |
679 | __attribute__((regparm(3))) | |
680 | void do_syscall_trace(struct pt_regs *regs, int entryexit) | |
681 | { | |
682 | /* do the secure computing check first */ | |
683 | secure_computing(regs->orig_eax); | |
684 | ||
685 | if (unlikely(current->audit_context)) { | |
686 | if (!entryexit) | |
687 | audit_syscall_entry(current, regs->orig_eax, | |
688 | regs->ebx, regs->ecx, | |
689 | regs->edx, regs->esi); | |
690 | else | |
691 | audit_syscall_exit(current, regs->eax); | |
692 | } | |
693 | ||
694 | if (!(current->ptrace & PT_PTRACED)) | |
695 | return; | |
696 | ||
697 | /* Fake a debug trap */ | |
698 | if (test_thread_flag(TIF_SINGLESTEP)) | |
699 | send_sigtrap(current, regs, 0); | |
700 | ||
701 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
702 | return; | |
703 | ||
704 | /* the 0x80 provides a way for the tracing parent to distinguish | |
705 | between a syscall stop and SIGTRAP delivery */ | |
706 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); | |
707 | ||
708 | /* | |
709 | * this isn't the same as continuing with a signal, but it will do | |
710 | * for normal use. strace only continues with a signal if the | |
711 | * stopping signal is not SIGTRAP. -brl | |
712 | */ | |
713 | if (current->exit_code) { | |
714 | send_sig(current->exit_code, current, 1); | |
715 | current->exit_code = 0; | |
716 | } | |
717 | } |