Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/ptrace.c | |
3 | * | |
4 | * (C) Copyright 1999 Linus Torvalds | |
5 | * | |
6 | * Common interfaces for "ptrace()" which we do not want | |
7 | * to continually duplicate across every architecture. | |
8 | */ | |
9 | ||
c59ede7b | 10 | #include <linux/capability.h> |
1da177e4 LT |
11 | #include <linux/module.h> |
12 | #include <linux/sched.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/highmem.h> | |
16 | #include <linux/pagemap.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/ptrace.h> | |
19 | #include <linux/security.h> | |
7ed20e1a | 20 | #include <linux/signal.h> |
a5cb013d | 21 | #include <linux/audit.h> |
b488893a | 22 | #include <linux/pid_namespace.h> |
1da177e4 LT |
23 | |
24 | #include <asm/pgtable.h> | |
25 | #include <asm/uaccess.h> | |
26 | ||
27 | /* | |
28 | * ptrace a task: make the debugger its new parent and | |
29 | * move it to the ptrace list. | |
30 | * | |
31 | * Must be called with the tasklist lock write-held. | |
32 | */ | |
36c8b586 | 33 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 34 | { |
524223ca | 35 | BUG_ON(!list_empty(&child->ptrace_list)); |
1da177e4 LT |
36 | if (child->parent == new_parent) |
37 | return; | |
38 | list_add(&child->ptrace_list, &child->parent->ptrace_children); | |
9b678ece | 39 | remove_parent(child); |
1da177e4 | 40 | child->parent = new_parent; |
9b678ece | 41 | add_parent(child); |
1da177e4 LT |
42 | } |
43 | ||
44 | /* | |
45 | * Turn a tracing stop into a normal stop now, since with no tracer there | |
46 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a | |
47 | * signal sent that would resume the child, but didn't because it was in | |
48 | * TASK_TRACED, resume it now. | |
49 | * Requires that irqs be disabled. | |
50 | */ | |
36c8b586 | 51 | void ptrace_untrace(struct task_struct *child) |
1da177e4 LT |
52 | { |
53 | spin_lock(&child->sighand->siglock); | |
6618a3e2 | 54 | if (task_is_traced(child)) { |
1da177e4 | 55 | if (child->signal->flags & SIGNAL_STOP_STOPPED) { |
d9ae90ac | 56 | __set_task_state(child, TASK_STOPPED); |
1da177e4 LT |
57 | } else { |
58 | signal_wake_up(child, 1); | |
59 | } | |
60 | } | |
61 | spin_unlock(&child->sighand->siglock); | |
62 | } | |
63 | ||
64 | /* | |
65 | * unptrace a task: move it back to its original parent and | |
66 | * remove it from the ptrace list. | |
67 | * | |
68 | * Must be called with the tasklist lock write-held. | |
69 | */ | |
36c8b586 | 70 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 71 | { |
5ecfbae0 ON |
72 | BUG_ON(!child->ptrace); |
73 | ||
1da177e4 LT |
74 | child->ptrace = 0; |
75 | if (!list_empty(&child->ptrace_list)) { | |
76 | list_del_init(&child->ptrace_list); | |
9b678ece | 77 | remove_parent(child); |
1da177e4 | 78 | child->parent = child->real_parent; |
9b678ece | 79 | add_parent(child); |
1da177e4 LT |
80 | } |
81 | ||
6618a3e2 | 82 | if (task_is_traced(child)) |
e57a5059 | 83 | ptrace_untrace(child); |
1da177e4 LT |
84 | } |
85 | ||
86 | /* | |
87 | * Check that we have indeed attached to the thing.. | |
88 | */ | |
89 | int ptrace_check_attach(struct task_struct *child, int kill) | |
90 | { | |
91 | int ret = -ESRCH; | |
92 | ||
93 | /* | |
94 | * We take the read lock around doing both checks to close a | |
95 | * possible race where someone else was tracing our child and | |
96 | * detached between these two checks. After this locked check, | |
97 | * we are sure that this is our traced child and that can only | |
98 | * be changed by us so it's not changing right after this. | |
99 | */ | |
100 | read_lock(&tasklist_lock); | |
101 | if ((child->ptrace & PT_PTRACED) && child->parent == current && | |
102 | (!(child->ptrace & PT_ATTACHED) || child->real_parent != current) | |
103 | && child->signal != NULL) { | |
104 | ret = 0; | |
105 | spin_lock_irq(&child->sighand->siglock); | |
d9ae90ac | 106 | if (task_is_stopped(child)) |
1da177e4 | 107 | child->state = TASK_TRACED; |
d9ae90ac | 108 | else if (!task_is_traced(child) && !kill) |
1da177e4 | 109 | ret = -ESRCH; |
1da177e4 LT |
110 | spin_unlock_irq(&child->sighand->siglock); |
111 | } | |
112 | read_unlock(&tasklist_lock); | |
113 | ||
d9ae90ac | 114 | if (!ret && !kill) |
1da177e4 | 115 | wait_task_inactive(child); |
1da177e4 LT |
116 | |
117 | /* All systems go.. */ | |
118 | return ret; | |
119 | } | |
120 | ||
831830b5 | 121 | int __ptrace_may_attach(struct task_struct *task) |
ab8d11be | 122 | { |
df26c40e EB |
123 | /* May we inspect the given task? |
124 | * This check is used both for attaching with ptrace | |
125 | * and for allowing access to sensitive information in /proc. | |
126 | * | |
127 | * ptrace_attach denies several cases that /proc allows | |
128 | * because setting up the necessary parent/child relationship | |
129 | * or halting the specified task is impossible. | |
130 | */ | |
131 | int dumpable = 0; | |
132 | /* Don't let security modules deny introspection */ | |
133 | if (task == current) | |
134 | return 0; | |
ab8d11be MS |
135 | if (((current->uid != task->euid) || |
136 | (current->uid != task->suid) || | |
137 | (current->uid != task->uid) || | |
138 | (current->gid != task->egid) || | |
139 | (current->gid != task->sgid) || | |
140 | (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) | |
141 | return -EPERM; | |
142 | smp_rmb(); | |
df26c40e | 143 | if (task->mm) |
6c5d5238 | 144 | dumpable = get_dumpable(task->mm); |
df26c40e | 145 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
ab8d11be MS |
146 | return -EPERM; |
147 | ||
148 | return security_ptrace(current, task); | |
149 | } | |
150 | ||
151 | int ptrace_may_attach(struct task_struct *task) | |
152 | { | |
153 | int err; | |
154 | task_lock(task); | |
831830b5 | 155 | err = __ptrace_may_attach(task); |
ab8d11be MS |
156 | task_unlock(task); |
157 | return !err; | |
158 | } | |
159 | ||
1da177e4 LT |
160 | int ptrace_attach(struct task_struct *task) |
161 | { | |
162 | int retval; | |
6175ecfe | 163 | unsigned long flags; |
f5b40e36 | 164 | |
a5cb013d AV |
165 | audit_ptrace(task); |
166 | ||
1da177e4 LT |
167 | retval = -EPERM; |
168 | if (task->pid <= 1) | |
f5b40e36 | 169 | goto out; |
bac0abd6 | 170 | if (same_thread_group(task, current)) |
f5b40e36 LT |
171 | goto out; |
172 | ||
f358166a LT |
173 | repeat: |
174 | /* | |
175 | * Nasty, nasty. | |
176 | * | |
177 | * We want to hold both the task-lock and the | |
178 | * tasklist_lock for writing at the same time. | |
179 | * But that's against the rules (tasklist_lock | |
180 | * is taken for reading by interrupts on other | |
181 | * cpu's that may have task_lock). | |
182 | */ | |
f5b40e36 | 183 | task_lock(task); |
6175ecfe | 184 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { |
f358166a LT |
185 | task_unlock(task); |
186 | do { | |
187 | cpu_relax(); | |
188 | } while (!write_can_lock(&tasklist_lock)); | |
189 | goto repeat; | |
190 | } | |
f5b40e36 | 191 | |
df26c40e EB |
192 | if (!task->mm) |
193 | goto bad; | |
1da177e4 LT |
194 | /* the same process cannot be attached many times */ |
195 | if (task->ptrace & PT_PTRACED) | |
196 | goto bad; | |
b8c9a187 | 197 | retval = __ptrace_may_attach(task); |
1da177e4 LT |
198 | if (retval) |
199 | goto bad; | |
200 | ||
201 | /* Go */ | |
202 | task->ptrace |= PT_PTRACED | ((task->real_parent != current) | |
203 | ? PT_ATTACHED : 0); | |
204 | if (capable(CAP_SYS_PTRACE)) | |
205 | task->ptrace |= PT_PTRACE_CAP; | |
1da177e4 | 206 | |
1da177e4 | 207 | __ptrace_link(task, current); |
1da177e4 LT |
208 | |
209 | force_sig_specific(SIGSTOP, task); | |
1da177e4 LT |
210 | |
211 | bad: | |
6175ecfe | 212 | write_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 | 213 | task_unlock(task); |
f5b40e36 | 214 | out: |
1da177e4 LT |
215 | return retval; |
216 | } | |
217 | ||
d5f70c00 | 218 | static inline void __ptrace_detach(struct task_struct *child, unsigned int data) |
5ecfbae0 ON |
219 | { |
220 | child->exit_code = data; | |
221 | /* .. re-parent .. */ | |
222 | __ptrace_unlink(child); | |
223 | /* .. and wake it up. */ | |
224 | if (child->exit_state != EXIT_ZOMBIE) | |
225 | wake_up_process(child); | |
226 | } | |
227 | ||
1da177e4 LT |
228 | int ptrace_detach(struct task_struct *child, unsigned int data) |
229 | { | |
7ed20e1a | 230 | if (!valid_signal(data)) |
5ecfbae0 | 231 | return -EIO; |
1da177e4 LT |
232 | |
233 | /* Architecture-specific hardware disable .. */ | |
234 | ptrace_disable(child); | |
7d941432 | 235 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 236 | |
1da177e4 | 237 | write_lock_irq(&tasklist_lock); |
d5f70c00 | 238 | /* protect against de_thread()->release_task() */ |
5ecfbae0 ON |
239 | if (child->ptrace) |
240 | __ptrace_detach(child, data); | |
1da177e4 LT |
241 | write_unlock_irq(&tasklist_lock); |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
1da177e4 LT |
246 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
247 | { | |
248 | int copied = 0; | |
249 | ||
250 | while (len > 0) { | |
251 | char buf[128]; | |
252 | int this_len, retval; | |
253 | ||
254 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
255 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
256 | if (!retval) { | |
257 | if (copied) | |
258 | break; | |
259 | return -EIO; | |
260 | } | |
261 | if (copy_to_user(dst, buf, retval)) | |
262 | return -EFAULT; | |
263 | copied += retval; | |
264 | src += retval; | |
265 | dst += retval; | |
266 | len -= retval; | |
267 | } | |
268 | return copied; | |
269 | } | |
270 | ||
271 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
272 | { | |
273 | int copied = 0; | |
274 | ||
275 | while (len > 0) { | |
276 | char buf[128]; | |
277 | int this_len, retval; | |
278 | ||
279 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
280 | if (copy_from_user(buf, src, this_len)) | |
281 | return -EFAULT; | |
282 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
283 | if (!retval) { | |
284 | if (copied) | |
285 | break; | |
286 | return -EIO; | |
287 | } | |
288 | copied += retval; | |
289 | src += retval; | |
290 | dst += retval; | |
291 | len -= retval; | |
292 | } | |
293 | return copied; | |
294 | } | |
295 | ||
296 | static int ptrace_setoptions(struct task_struct *child, long data) | |
297 | { | |
298 | child->ptrace &= ~PT_TRACE_MASK; | |
299 | ||
300 | if (data & PTRACE_O_TRACESYSGOOD) | |
301 | child->ptrace |= PT_TRACESYSGOOD; | |
302 | ||
303 | if (data & PTRACE_O_TRACEFORK) | |
304 | child->ptrace |= PT_TRACE_FORK; | |
305 | ||
306 | if (data & PTRACE_O_TRACEVFORK) | |
307 | child->ptrace |= PT_TRACE_VFORK; | |
308 | ||
309 | if (data & PTRACE_O_TRACECLONE) | |
310 | child->ptrace |= PT_TRACE_CLONE; | |
311 | ||
312 | if (data & PTRACE_O_TRACEEXEC) | |
313 | child->ptrace |= PT_TRACE_EXEC; | |
314 | ||
315 | if (data & PTRACE_O_TRACEVFORKDONE) | |
316 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
317 | ||
318 | if (data & PTRACE_O_TRACEEXIT) | |
319 | child->ptrace |= PT_TRACE_EXIT; | |
320 | ||
321 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
322 | } | |
323 | ||
324 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) | |
325 | { | |
326 | siginfo_t lastinfo; | |
327 | int error = -ESRCH; | |
328 | ||
329 | read_lock(&tasklist_lock); | |
330 | if (likely(child->sighand != NULL)) { | |
331 | error = -EINVAL; | |
332 | spin_lock_irq(&child->sighand->siglock); | |
333 | if (likely(child->last_siginfo != NULL)) { | |
334 | lastinfo = *child->last_siginfo; | |
335 | error = 0; | |
336 | } | |
337 | spin_unlock_irq(&child->sighand->siglock); | |
338 | } | |
339 | read_unlock(&tasklist_lock); | |
340 | if (!error) | |
341 | return copy_siginfo_to_user(data, &lastinfo); | |
342 | return error; | |
343 | } | |
344 | ||
345 | static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) | |
346 | { | |
347 | siginfo_t newinfo; | |
348 | int error = -ESRCH; | |
349 | ||
350 | if (copy_from_user(&newinfo, data, sizeof (siginfo_t))) | |
351 | return -EFAULT; | |
352 | ||
353 | read_lock(&tasklist_lock); | |
354 | if (likely(child->sighand != NULL)) { | |
355 | error = -EINVAL; | |
356 | spin_lock_irq(&child->sighand->siglock); | |
357 | if (likely(child->last_siginfo != NULL)) { | |
358 | *child->last_siginfo = newinfo; | |
359 | error = 0; | |
360 | } | |
361 | spin_unlock_irq(&child->sighand->siglock); | |
362 | } | |
363 | read_unlock(&tasklist_lock); | |
364 | return error; | |
365 | } | |
366 | ||
36df29d7 RM |
367 | |
368 | #ifdef PTRACE_SINGLESTEP | |
369 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
370 | #else | |
371 | #define is_singlestep(request) 0 | |
372 | #endif | |
373 | ||
5b88abbf RM |
374 | #ifdef PTRACE_SINGLEBLOCK |
375 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
376 | #else | |
377 | #define is_singleblock(request) 0 | |
378 | #endif | |
379 | ||
36df29d7 RM |
380 | #ifdef PTRACE_SYSEMU |
381 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
382 | #else | |
383 | #define is_sysemu_singlestep(request) 0 | |
384 | #endif | |
385 | ||
386 | static int ptrace_resume(struct task_struct *child, long request, long data) | |
387 | { | |
388 | if (!valid_signal(data)) | |
389 | return -EIO; | |
390 | ||
391 | if (request == PTRACE_SYSCALL) | |
392 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
393 | else | |
394 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
395 | ||
396 | #ifdef TIF_SYSCALL_EMU | |
397 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
398 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
399 | else | |
400 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
401 | #endif | |
402 | ||
5b88abbf RM |
403 | if (is_singleblock(request)) { |
404 | if (unlikely(!arch_has_block_step())) | |
405 | return -EIO; | |
406 | user_enable_block_step(child); | |
407 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
408 | if (unlikely(!arch_has_single_step())) |
409 | return -EIO; | |
410 | user_enable_single_step(child); | |
411 | } | |
412 | else | |
413 | user_disable_single_step(child); | |
414 | ||
415 | child->exit_code = data; | |
416 | wake_up_process(child); | |
417 | ||
418 | return 0; | |
419 | } | |
420 | ||
1da177e4 LT |
421 | int ptrace_request(struct task_struct *child, long request, |
422 | long addr, long data) | |
423 | { | |
424 | int ret = -EIO; | |
425 | ||
426 | switch (request) { | |
16c3e389 RM |
427 | case PTRACE_PEEKTEXT: |
428 | case PTRACE_PEEKDATA: | |
429 | return generic_ptrace_peekdata(child, addr, data); | |
430 | case PTRACE_POKETEXT: | |
431 | case PTRACE_POKEDATA: | |
432 | return generic_ptrace_pokedata(child, addr, data); | |
433 | ||
1da177e4 LT |
434 | #ifdef PTRACE_OLDSETOPTIONS |
435 | case PTRACE_OLDSETOPTIONS: | |
436 | #endif | |
437 | case PTRACE_SETOPTIONS: | |
438 | ret = ptrace_setoptions(child, data); | |
439 | break; | |
440 | case PTRACE_GETEVENTMSG: | |
441 | ret = put_user(child->ptrace_message, (unsigned long __user *) data); | |
442 | break; | |
443 | case PTRACE_GETSIGINFO: | |
444 | ret = ptrace_getsiginfo(child, (siginfo_t __user *) data); | |
445 | break; | |
446 | case PTRACE_SETSIGINFO: | |
447 | ret = ptrace_setsiginfo(child, (siginfo_t __user *) data); | |
448 | break; | |
1bcf5482 AD |
449 | case PTRACE_DETACH: /* detach a process that was attached. */ |
450 | ret = ptrace_detach(child, data); | |
451 | break; | |
36df29d7 RM |
452 | |
453 | #ifdef PTRACE_SINGLESTEP | |
454 | case PTRACE_SINGLESTEP: | |
455 | #endif | |
5b88abbf RM |
456 | #ifdef PTRACE_SINGLEBLOCK |
457 | case PTRACE_SINGLEBLOCK: | |
458 | #endif | |
36df29d7 RM |
459 | #ifdef PTRACE_SYSEMU |
460 | case PTRACE_SYSEMU: | |
461 | case PTRACE_SYSEMU_SINGLESTEP: | |
462 | #endif | |
463 | case PTRACE_SYSCALL: | |
464 | case PTRACE_CONT: | |
465 | return ptrace_resume(child, request, data); | |
466 | ||
467 | case PTRACE_KILL: | |
468 | if (child->exit_state) /* already dead */ | |
469 | return 0; | |
470 | return ptrace_resume(child, request, SIGKILL); | |
471 | ||
1da177e4 LT |
472 | default: |
473 | break; | |
474 | } | |
475 | ||
476 | return ret; | |
477 | } | |
481bed45 | 478 | |
6b9c7ed8 CH |
479 | /** |
480 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
481 | * | |
482 | * Performs checks and sets PT_PTRACED. | |
483 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
484 | */ | |
485 | int ptrace_traceme(void) | |
481bed45 | 486 | { |
f5b40e36 | 487 | int ret = -EPERM; |
481bed45 CH |
488 | |
489 | /* | |
6b9c7ed8 CH |
490 | * Are we already being traced? |
491 | */ | |
f5b40e36 LT |
492 | task_lock(current); |
493 | if (!(current->ptrace & PT_PTRACED)) { | |
494 | ret = security_ptrace(current->parent, current); | |
495 | /* | |
496 | * Set the ptrace bit in the process ptrace flags. | |
497 | */ | |
498 | if (!ret) | |
499 | current->ptrace |= PT_PTRACED; | |
500 | } | |
501 | task_unlock(current); | |
502 | return ret; | |
6b9c7ed8 | 503 | } |
481bed45 | 504 | |
6b9c7ed8 CH |
505 | /** |
506 | * ptrace_get_task_struct -- grab a task struct reference for ptrace | |
507 | * @pid: process id to grab a task_struct reference of | |
508 | * | |
509 | * This function is a helper for ptrace implementations. It checks | |
510 | * permissions and then grabs a task struct for use of the actual | |
511 | * ptrace implementation. | |
512 | * | |
513 | * Returns the task_struct for @pid or an ERR_PTR() on failure. | |
514 | */ | |
515 | struct task_struct *ptrace_get_task_struct(pid_t pid) | |
516 | { | |
517 | struct task_struct *child; | |
481bed45 CH |
518 | |
519 | /* | |
6b9c7ed8 | 520 | * Tracing init is not allowed. |
481bed45 CH |
521 | */ |
522 | if (pid == 1) | |
6b9c7ed8 | 523 | return ERR_PTR(-EPERM); |
481bed45 | 524 | |
481bed45 | 525 | read_lock(&tasklist_lock); |
228ebcbe | 526 | child = find_task_by_vpid(pid); |
481bed45 CH |
527 | if (child) |
528 | get_task_struct(child); | |
f400e198 | 529 | |
481bed45 CH |
530 | read_unlock(&tasklist_lock); |
531 | if (!child) | |
6b9c7ed8 CH |
532 | return ERR_PTR(-ESRCH); |
533 | return child; | |
481bed45 CH |
534 | } |
535 | ||
0ac15559 CH |
536 | #ifndef arch_ptrace_attach |
537 | #define arch_ptrace_attach(child) do { } while (0) | |
538 | #endif | |
539 | ||
6b9c7ed8 | 540 | #ifndef __ARCH_SYS_PTRACE |
481bed45 CH |
541 | asmlinkage long sys_ptrace(long request, long pid, long addr, long data) |
542 | { | |
543 | struct task_struct *child; | |
544 | long ret; | |
545 | ||
546 | /* | |
547 | * This lock_kernel fixes a subtle race with suid exec | |
548 | */ | |
549 | lock_kernel(); | |
6b9c7ed8 CH |
550 | if (request == PTRACE_TRACEME) { |
551 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
552 | if (!ret) |
553 | arch_ptrace_attach(current); | |
481bed45 | 554 | goto out; |
6b9c7ed8 CH |
555 | } |
556 | ||
557 | child = ptrace_get_task_struct(pid); | |
558 | if (IS_ERR(child)) { | |
559 | ret = PTR_ERR(child); | |
560 | goto out; | |
561 | } | |
481bed45 CH |
562 | |
563 | if (request == PTRACE_ATTACH) { | |
564 | ret = ptrace_attach(child); | |
0ac15559 CH |
565 | /* |
566 | * Some architectures need to do book-keeping after | |
567 | * a ptrace attach. | |
568 | */ | |
569 | if (!ret) | |
570 | arch_ptrace_attach(child); | |
005f18df | 571 | goto out_put_task_struct; |
481bed45 CH |
572 | } |
573 | ||
574 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
575 | if (ret < 0) | |
576 | goto out_put_task_struct; | |
577 | ||
578 | ret = arch_ptrace(child, request, addr, data); | |
579 | if (ret < 0) | |
580 | goto out_put_task_struct; | |
581 | ||
582 | out_put_task_struct: | |
583 | put_task_struct(child); | |
584 | out: | |
585 | unlock_kernel(); | |
586 | return ret; | |
587 | } | |
588 | #endif /* __ARCH_SYS_PTRACE */ | |
76647323 AD |
589 | |
590 | int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) | |
591 | { | |
592 | unsigned long tmp; | |
593 | int copied; | |
594 | ||
595 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
596 | if (copied != sizeof(tmp)) | |
597 | return -EIO; | |
598 | return put_user(tmp, (unsigned long __user *)data); | |
599 | } | |
f284ce72 AD |
600 | |
601 | int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) | |
602 | { | |
603 | int copied; | |
604 | ||
605 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
606 | return (copied == sizeof(data)) ? 0 : -EIO; | |
607 | } | |
032d82d9 RM |
608 | |
609 | #ifdef CONFIG_COMPAT | |
610 | #include <linux/compat.h> | |
611 | ||
612 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
613 | compat_ulong_t addr, compat_ulong_t data) | |
614 | { | |
615 | compat_ulong_t __user *datap = compat_ptr(data); | |
616 | compat_ulong_t word; | |
617 | int ret; | |
618 | ||
619 | switch (request) { | |
620 | case PTRACE_PEEKTEXT: | |
621 | case PTRACE_PEEKDATA: | |
622 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
623 | if (ret != sizeof(word)) | |
624 | ret = -EIO; | |
625 | else | |
626 | ret = put_user(word, datap); | |
627 | break; | |
628 | ||
629 | case PTRACE_POKETEXT: | |
630 | case PTRACE_POKEDATA: | |
631 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
632 | ret = (ret != sizeof(data) ? -EIO : 0); | |
633 | break; | |
634 | ||
635 | case PTRACE_GETEVENTMSG: | |
636 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
637 | break; | |
638 | ||
639 | default: | |
640 | ret = ptrace_request(child, request, addr, data); | |
641 | } | |
642 | ||
643 | return ret; | |
644 | } | |
c269f196 RM |
645 | |
646 | #ifdef __ARCH_WANT_COMPAT_SYS_PTRACE | |
647 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, | |
648 | compat_long_t addr, compat_long_t data) | |
649 | { | |
650 | struct task_struct *child; | |
651 | long ret; | |
652 | ||
653 | /* | |
654 | * This lock_kernel fixes a subtle race with suid exec | |
655 | */ | |
656 | lock_kernel(); | |
657 | if (request == PTRACE_TRACEME) { | |
658 | ret = ptrace_traceme(); | |
659 | goto out; | |
660 | } | |
661 | ||
662 | child = ptrace_get_task_struct(pid); | |
663 | if (IS_ERR(child)) { | |
664 | ret = PTR_ERR(child); | |
665 | goto out; | |
666 | } | |
667 | ||
668 | if (request == PTRACE_ATTACH) { | |
669 | ret = ptrace_attach(child); | |
670 | /* | |
671 | * Some architectures need to do book-keeping after | |
672 | * a ptrace attach. | |
673 | */ | |
674 | if (!ret) | |
675 | arch_ptrace_attach(child); | |
676 | goto out_put_task_struct; | |
677 | } | |
678 | ||
679 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
680 | if (!ret) | |
681 | ret = compat_arch_ptrace(child, request, addr, data); | |
682 | ||
683 | out_put_task_struct: | |
684 | put_task_struct(child); | |
685 | out: | |
686 | unlock_kernel(); | |
687 | return ret; | |
688 | } | |
689 | #endif /* __ARCH_WANT_COMPAT_SYS_PTRACE */ | |
690 | ||
032d82d9 | 691 | #endif /* CONFIG_COMPAT */ |