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> |
f17d30a8 | 23 | #include <linux/syscalls.h> |
1da177e4 LT |
24 | |
25 | #include <asm/pgtable.h> | |
26 | #include <asm/uaccess.h> | |
27 | ||
28 | /* | |
29 | * ptrace a task: make the debugger its new parent and | |
30 | * move it to the ptrace list. | |
31 | * | |
32 | * Must be called with the tasklist lock write-held. | |
33 | */ | |
36c8b586 | 34 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
1da177e4 | 35 | { |
524223ca | 36 | BUG_ON(!list_empty(&child->ptrace_list)); |
1da177e4 LT |
37 | if (child->parent == new_parent) |
38 | return; | |
39 | list_add(&child->ptrace_list, &child->parent->ptrace_children); | |
9b678ece | 40 | remove_parent(child); |
1da177e4 | 41 | child->parent = new_parent; |
9b678ece | 42 | add_parent(child); |
1da177e4 LT |
43 | } |
44 | ||
45 | /* | |
46 | * Turn a tracing stop into a normal stop now, since with no tracer there | |
47 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a | |
48 | * signal sent that would resume the child, but didn't because it was in | |
49 | * TASK_TRACED, resume it now. | |
50 | * Requires that irqs be disabled. | |
51 | */ | |
36c8b586 | 52 | void ptrace_untrace(struct task_struct *child) |
1da177e4 LT |
53 | { |
54 | spin_lock(&child->sighand->siglock); | |
6618a3e2 | 55 | if (task_is_traced(child)) { |
1da177e4 | 56 | if (child->signal->flags & SIGNAL_STOP_STOPPED) { |
d9ae90ac | 57 | __set_task_state(child, TASK_STOPPED); |
1da177e4 LT |
58 | } else { |
59 | signal_wake_up(child, 1); | |
60 | } | |
61 | } | |
62 | spin_unlock(&child->sighand->siglock); | |
63 | } | |
64 | ||
65 | /* | |
66 | * unptrace a task: move it back to its original parent and | |
67 | * remove it from the ptrace list. | |
68 | * | |
69 | * Must be called with the tasklist lock write-held. | |
70 | */ | |
36c8b586 | 71 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 72 | { |
5ecfbae0 ON |
73 | BUG_ON(!child->ptrace); |
74 | ||
1da177e4 LT |
75 | child->ptrace = 0; |
76 | if (!list_empty(&child->ptrace_list)) { | |
77 | list_del_init(&child->ptrace_list); | |
9b678ece | 78 | remove_parent(child); |
1da177e4 | 79 | child->parent = child->real_parent; |
9b678ece | 80 | add_parent(child); |
1da177e4 LT |
81 | } |
82 | ||
6618a3e2 | 83 | if (task_is_traced(child)) |
e57a5059 | 84 | ptrace_untrace(child); |
1da177e4 LT |
85 | } |
86 | ||
87 | /* | |
88 | * Check that we have indeed attached to the thing.. | |
89 | */ | |
90 | int ptrace_check_attach(struct task_struct *child, int kill) | |
91 | { | |
92 | int ret = -ESRCH; | |
93 | ||
94 | /* | |
95 | * We take the read lock around doing both checks to close a | |
96 | * possible race where someone else was tracing our child and | |
97 | * detached between these two checks. After this locked check, | |
98 | * we are sure that this is our traced child and that can only | |
99 | * be changed by us so it's not changing right after this. | |
100 | */ | |
101 | read_lock(&tasklist_lock); | |
102 | if ((child->ptrace & PT_PTRACED) && child->parent == current && | |
103 | (!(child->ptrace & PT_ATTACHED) || child->real_parent != current) | |
104 | && child->signal != NULL) { | |
105 | ret = 0; | |
106 | spin_lock_irq(&child->sighand->siglock); | |
d9ae90ac | 107 | if (task_is_stopped(child)) |
1da177e4 | 108 | child->state = TASK_TRACED; |
d9ae90ac | 109 | else if (!task_is_traced(child) && !kill) |
1da177e4 | 110 | ret = -ESRCH; |
1da177e4 LT |
111 | spin_unlock_irq(&child->sighand->siglock); |
112 | } | |
113 | read_unlock(&tasklist_lock); | |
114 | ||
d9ae90ac | 115 | if (!ret && !kill) |
1da177e4 | 116 | wait_task_inactive(child); |
1da177e4 LT |
117 | |
118 | /* All systems go.. */ | |
119 | return ret; | |
120 | } | |
121 | ||
831830b5 | 122 | int __ptrace_may_attach(struct task_struct *task) |
ab8d11be | 123 | { |
df26c40e EB |
124 | /* May we inspect the given task? |
125 | * This check is used both for attaching with ptrace | |
126 | * and for allowing access to sensitive information in /proc. | |
127 | * | |
128 | * ptrace_attach denies several cases that /proc allows | |
129 | * because setting up the necessary parent/child relationship | |
130 | * or halting the specified task is impossible. | |
131 | */ | |
132 | int dumpable = 0; | |
133 | /* Don't let security modules deny introspection */ | |
134 | if (task == current) | |
135 | return 0; | |
ab8d11be MS |
136 | if (((current->uid != task->euid) || |
137 | (current->uid != task->suid) || | |
138 | (current->uid != task->uid) || | |
139 | (current->gid != task->egid) || | |
140 | (current->gid != task->sgid) || | |
141 | (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) | |
142 | return -EPERM; | |
143 | smp_rmb(); | |
df26c40e | 144 | if (task->mm) |
6c5d5238 | 145 | dumpable = get_dumpable(task->mm); |
df26c40e | 146 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
ab8d11be MS |
147 | return -EPERM; |
148 | ||
149 | return security_ptrace(current, task); | |
150 | } | |
151 | ||
152 | int ptrace_may_attach(struct task_struct *task) | |
153 | { | |
154 | int err; | |
155 | task_lock(task); | |
831830b5 | 156 | err = __ptrace_may_attach(task); |
ab8d11be MS |
157 | task_unlock(task); |
158 | return !err; | |
159 | } | |
160 | ||
1da177e4 LT |
161 | int ptrace_attach(struct task_struct *task) |
162 | { | |
163 | int retval; | |
6175ecfe | 164 | unsigned long flags; |
f5b40e36 | 165 | |
a5cb013d AV |
166 | audit_ptrace(task); |
167 | ||
1da177e4 LT |
168 | retval = -EPERM; |
169 | if (task->pid <= 1) | |
f5b40e36 | 170 | goto out; |
bac0abd6 | 171 | if (same_thread_group(task, current)) |
f5b40e36 LT |
172 | goto out; |
173 | ||
f358166a LT |
174 | repeat: |
175 | /* | |
176 | * Nasty, nasty. | |
177 | * | |
178 | * We want to hold both the task-lock and the | |
179 | * tasklist_lock for writing at the same time. | |
180 | * But that's against the rules (tasklist_lock | |
181 | * is taken for reading by interrupts on other | |
182 | * cpu's that may have task_lock). | |
183 | */ | |
f5b40e36 | 184 | task_lock(task); |
6175ecfe | 185 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { |
f358166a LT |
186 | task_unlock(task); |
187 | do { | |
188 | cpu_relax(); | |
189 | } while (!write_can_lock(&tasklist_lock)); | |
190 | goto repeat; | |
191 | } | |
f5b40e36 | 192 | |
df26c40e EB |
193 | if (!task->mm) |
194 | goto bad; | |
1da177e4 LT |
195 | /* the same process cannot be attached many times */ |
196 | if (task->ptrace & PT_PTRACED) | |
197 | goto bad; | |
b8c9a187 | 198 | retval = __ptrace_may_attach(task); |
1da177e4 LT |
199 | if (retval) |
200 | goto bad; | |
201 | ||
202 | /* Go */ | |
203 | task->ptrace |= PT_PTRACED | ((task->real_parent != current) | |
204 | ? PT_ATTACHED : 0); | |
205 | if (capable(CAP_SYS_PTRACE)) | |
206 | task->ptrace |= PT_PTRACE_CAP; | |
1da177e4 | 207 | |
1da177e4 | 208 | __ptrace_link(task, current); |
1da177e4 LT |
209 | |
210 | force_sig_specific(SIGSTOP, task); | |
1da177e4 LT |
211 | |
212 | bad: | |
6175ecfe | 213 | write_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 | 214 | task_unlock(task); |
f5b40e36 | 215 | out: |
1da177e4 LT |
216 | return retval; |
217 | } | |
218 | ||
d5f70c00 | 219 | static inline void __ptrace_detach(struct task_struct *child, unsigned int data) |
5ecfbae0 ON |
220 | { |
221 | child->exit_code = data; | |
222 | /* .. re-parent .. */ | |
223 | __ptrace_unlink(child); | |
224 | /* .. and wake it up. */ | |
225 | if (child->exit_state != EXIT_ZOMBIE) | |
226 | wake_up_process(child); | |
227 | } | |
228 | ||
1da177e4 LT |
229 | int ptrace_detach(struct task_struct *child, unsigned int data) |
230 | { | |
7ed20e1a | 231 | if (!valid_signal(data)) |
5ecfbae0 | 232 | return -EIO; |
1da177e4 LT |
233 | |
234 | /* Architecture-specific hardware disable .. */ | |
235 | ptrace_disable(child); | |
7d941432 | 236 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 237 | |
1da177e4 | 238 | write_lock_irq(&tasklist_lock); |
d5f70c00 | 239 | /* protect against de_thread()->release_task() */ |
5ecfbae0 ON |
240 | if (child->ptrace) |
241 | __ptrace_detach(child, data); | |
1da177e4 LT |
242 | write_unlock_irq(&tasklist_lock); |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
1da177e4 LT |
247 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
248 | { | |
249 | int copied = 0; | |
250 | ||
251 | while (len > 0) { | |
252 | char buf[128]; | |
253 | int this_len, retval; | |
254 | ||
255 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
256 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
257 | if (!retval) { | |
258 | if (copied) | |
259 | break; | |
260 | return -EIO; | |
261 | } | |
262 | if (copy_to_user(dst, buf, retval)) | |
263 | return -EFAULT; | |
264 | copied += retval; | |
265 | src += retval; | |
266 | dst += retval; | |
267 | len -= retval; | |
268 | } | |
269 | return copied; | |
270 | } | |
271 | ||
272 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
273 | { | |
274 | int copied = 0; | |
275 | ||
276 | while (len > 0) { | |
277 | char buf[128]; | |
278 | int this_len, retval; | |
279 | ||
280 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
281 | if (copy_from_user(buf, src, this_len)) | |
282 | return -EFAULT; | |
283 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
284 | if (!retval) { | |
285 | if (copied) | |
286 | break; | |
287 | return -EIO; | |
288 | } | |
289 | copied += retval; | |
290 | src += retval; | |
291 | dst += retval; | |
292 | len -= retval; | |
293 | } | |
294 | return copied; | |
295 | } | |
296 | ||
297 | static int ptrace_setoptions(struct task_struct *child, long data) | |
298 | { | |
299 | child->ptrace &= ~PT_TRACE_MASK; | |
300 | ||
301 | if (data & PTRACE_O_TRACESYSGOOD) | |
302 | child->ptrace |= PT_TRACESYSGOOD; | |
303 | ||
304 | if (data & PTRACE_O_TRACEFORK) | |
305 | child->ptrace |= PT_TRACE_FORK; | |
306 | ||
307 | if (data & PTRACE_O_TRACEVFORK) | |
308 | child->ptrace |= PT_TRACE_VFORK; | |
309 | ||
310 | if (data & PTRACE_O_TRACECLONE) | |
311 | child->ptrace |= PT_TRACE_CLONE; | |
312 | ||
313 | if (data & PTRACE_O_TRACEEXEC) | |
314 | child->ptrace |= PT_TRACE_EXEC; | |
315 | ||
316 | if (data & PTRACE_O_TRACEVFORKDONE) | |
317 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
318 | ||
319 | if (data & PTRACE_O_TRACEEXIT) | |
320 | child->ptrace |= PT_TRACE_EXIT; | |
321 | ||
322 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
323 | } | |
324 | ||
325 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) | |
326 | { | |
327 | siginfo_t lastinfo; | |
328 | int error = -ESRCH; | |
329 | ||
330 | read_lock(&tasklist_lock); | |
331 | if (likely(child->sighand != NULL)) { | |
332 | error = -EINVAL; | |
333 | spin_lock_irq(&child->sighand->siglock); | |
334 | if (likely(child->last_siginfo != NULL)) { | |
335 | lastinfo = *child->last_siginfo; | |
336 | error = 0; | |
337 | } | |
338 | spin_unlock_irq(&child->sighand->siglock); | |
339 | } | |
340 | read_unlock(&tasklist_lock); | |
341 | if (!error) | |
342 | return copy_siginfo_to_user(data, &lastinfo); | |
343 | return error; | |
344 | } | |
345 | ||
346 | static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) | |
347 | { | |
348 | siginfo_t newinfo; | |
349 | int error = -ESRCH; | |
350 | ||
351 | if (copy_from_user(&newinfo, data, sizeof (siginfo_t))) | |
352 | return -EFAULT; | |
353 | ||
354 | read_lock(&tasklist_lock); | |
355 | if (likely(child->sighand != NULL)) { | |
356 | error = -EINVAL; | |
357 | spin_lock_irq(&child->sighand->siglock); | |
358 | if (likely(child->last_siginfo != NULL)) { | |
359 | *child->last_siginfo = newinfo; | |
360 | error = 0; | |
361 | } | |
362 | spin_unlock_irq(&child->sighand->siglock); | |
363 | } | |
364 | read_unlock(&tasklist_lock); | |
365 | return error; | |
366 | } | |
367 | ||
36df29d7 RM |
368 | |
369 | #ifdef PTRACE_SINGLESTEP | |
370 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
371 | #else | |
372 | #define is_singlestep(request) 0 | |
373 | #endif | |
374 | ||
5b88abbf RM |
375 | #ifdef PTRACE_SINGLEBLOCK |
376 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
377 | #else | |
378 | #define is_singleblock(request) 0 | |
379 | #endif | |
380 | ||
36df29d7 RM |
381 | #ifdef PTRACE_SYSEMU |
382 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
383 | #else | |
384 | #define is_sysemu_singlestep(request) 0 | |
385 | #endif | |
386 | ||
387 | static int ptrace_resume(struct task_struct *child, long request, long data) | |
388 | { | |
389 | if (!valid_signal(data)) | |
390 | return -EIO; | |
391 | ||
392 | if (request == PTRACE_SYSCALL) | |
393 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
394 | else | |
395 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
396 | ||
397 | #ifdef TIF_SYSCALL_EMU | |
398 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
399 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
400 | else | |
401 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
402 | #endif | |
403 | ||
5b88abbf RM |
404 | if (is_singleblock(request)) { |
405 | if (unlikely(!arch_has_block_step())) | |
406 | return -EIO; | |
407 | user_enable_block_step(child); | |
408 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
409 | if (unlikely(!arch_has_single_step())) |
410 | return -EIO; | |
411 | user_enable_single_step(child); | |
412 | } | |
413 | else | |
414 | user_disable_single_step(child); | |
415 | ||
416 | child->exit_code = data; | |
417 | wake_up_process(child); | |
418 | ||
419 | return 0; | |
420 | } | |
421 | ||
1da177e4 LT |
422 | int ptrace_request(struct task_struct *child, long request, |
423 | long addr, long data) | |
424 | { | |
425 | int ret = -EIO; | |
426 | ||
427 | switch (request) { | |
16c3e389 RM |
428 | case PTRACE_PEEKTEXT: |
429 | case PTRACE_PEEKDATA: | |
430 | return generic_ptrace_peekdata(child, addr, data); | |
431 | case PTRACE_POKETEXT: | |
432 | case PTRACE_POKEDATA: | |
433 | return generic_ptrace_pokedata(child, addr, data); | |
434 | ||
1da177e4 LT |
435 | #ifdef PTRACE_OLDSETOPTIONS |
436 | case PTRACE_OLDSETOPTIONS: | |
437 | #endif | |
438 | case PTRACE_SETOPTIONS: | |
439 | ret = ptrace_setoptions(child, data); | |
440 | break; | |
441 | case PTRACE_GETEVENTMSG: | |
442 | ret = put_user(child->ptrace_message, (unsigned long __user *) data); | |
443 | break; | |
444 | case PTRACE_GETSIGINFO: | |
445 | ret = ptrace_getsiginfo(child, (siginfo_t __user *) data); | |
446 | break; | |
447 | case PTRACE_SETSIGINFO: | |
448 | ret = ptrace_setsiginfo(child, (siginfo_t __user *) data); | |
449 | break; | |
1bcf5482 AD |
450 | case PTRACE_DETACH: /* detach a process that was attached. */ |
451 | ret = ptrace_detach(child, data); | |
452 | break; | |
36df29d7 RM |
453 | |
454 | #ifdef PTRACE_SINGLESTEP | |
455 | case PTRACE_SINGLESTEP: | |
456 | #endif | |
5b88abbf RM |
457 | #ifdef PTRACE_SINGLEBLOCK |
458 | case PTRACE_SINGLEBLOCK: | |
459 | #endif | |
36df29d7 RM |
460 | #ifdef PTRACE_SYSEMU |
461 | case PTRACE_SYSEMU: | |
462 | case PTRACE_SYSEMU_SINGLESTEP: | |
463 | #endif | |
464 | case PTRACE_SYSCALL: | |
465 | case PTRACE_CONT: | |
466 | return ptrace_resume(child, request, data); | |
467 | ||
468 | case PTRACE_KILL: | |
469 | if (child->exit_state) /* already dead */ | |
470 | return 0; | |
471 | return ptrace_resume(child, request, SIGKILL); | |
472 | ||
1da177e4 LT |
473 | default: |
474 | break; | |
475 | } | |
476 | ||
477 | return ret; | |
478 | } | |
481bed45 | 479 | |
6b9c7ed8 CH |
480 | /** |
481 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
482 | * | |
483 | * Performs checks and sets PT_PTRACED. | |
484 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
485 | */ | |
486 | int ptrace_traceme(void) | |
481bed45 | 487 | { |
f5b40e36 | 488 | int ret = -EPERM; |
481bed45 CH |
489 | |
490 | /* | |
6b9c7ed8 CH |
491 | * Are we already being traced? |
492 | */ | |
f5b40e36 LT |
493 | task_lock(current); |
494 | if (!(current->ptrace & PT_PTRACED)) { | |
495 | ret = security_ptrace(current->parent, current); | |
496 | /* | |
497 | * Set the ptrace bit in the process ptrace flags. | |
498 | */ | |
499 | if (!ret) | |
500 | current->ptrace |= PT_PTRACED; | |
501 | } | |
502 | task_unlock(current); | |
503 | return ret; | |
6b9c7ed8 | 504 | } |
481bed45 | 505 | |
6b9c7ed8 CH |
506 | /** |
507 | * ptrace_get_task_struct -- grab a task struct reference for ptrace | |
508 | * @pid: process id to grab a task_struct reference of | |
509 | * | |
510 | * This function is a helper for ptrace implementations. It checks | |
511 | * permissions and then grabs a task struct for use of the actual | |
512 | * ptrace implementation. | |
513 | * | |
514 | * Returns the task_struct for @pid or an ERR_PTR() on failure. | |
515 | */ | |
516 | struct task_struct *ptrace_get_task_struct(pid_t pid) | |
517 | { | |
518 | struct task_struct *child; | |
481bed45 CH |
519 | |
520 | /* | |
6b9c7ed8 | 521 | * Tracing init is not allowed. |
481bed45 CH |
522 | */ |
523 | if (pid == 1) | |
6b9c7ed8 | 524 | return ERR_PTR(-EPERM); |
481bed45 | 525 | |
481bed45 | 526 | read_lock(&tasklist_lock); |
228ebcbe | 527 | child = find_task_by_vpid(pid); |
481bed45 CH |
528 | if (child) |
529 | get_task_struct(child); | |
f400e198 | 530 | |
481bed45 CH |
531 | read_unlock(&tasklist_lock); |
532 | if (!child) | |
6b9c7ed8 CH |
533 | return ERR_PTR(-ESRCH); |
534 | return child; | |
481bed45 CH |
535 | } |
536 | ||
0ac15559 CH |
537 | #ifndef arch_ptrace_attach |
538 | #define arch_ptrace_attach(child) do { } while (0) | |
539 | #endif | |
540 | ||
6b9c7ed8 | 541 | #ifndef __ARCH_SYS_PTRACE |
481bed45 CH |
542 | asmlinkage long sys_ptrace(long request, long pid, long addr, long data) |
543 | { | |
544 | struct task_struct *child; | |
545 | long ret; | |
546 | ||
547 | /* | |
548 | * This lock_kernel fixes a subtle race with suid exec | |
549 | */ | |
550 | lock_kernel(); | |
6b9c7ed8 CH |
551 | if (request == PTRACE_TRACEME) { |
552 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
553 | if (!ret) |
554 | arch_ptrace_attach(current); | |
481bed45 | 555 | goto out; |
6b9c7ed8 CH |
556 | } |
557 | ||
558 | child = ptrace_get_task_struct(pid); | |
559 | if (IS_ERR(child)) { | |
560 | ret = PTR_ERR(child); | |
561 | goto out; | |
562 | } | |
481bed45 CH |
563 | |
564 | if (request == PTRACE_ATTACH) { | |
565 | ret = ptrace_attach(child); | |
0ac15559 CH |
566 | /* |
567 | * Some architectures need to do book-keeping after | |
568 | * a ptrace attach. | |
569 | */ | |
570 | if (!ret) | |
571 | arch_ptrace_attach(child); | |
005f18df | 572 | goto out_put_task_struct; |
481bed45 CH |
573 | } |
574 | ||
575 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
576 | if (ret < 0) | |
577 | goto out_put_task_struct; | |
578 | ||
579 | ret = arch_ptrace(child, request, addr, data); | |
580 | if (ret < 0) | |
581 | goto out_put_task_struct; | |
582 | ||
583 | out_put_task_struct: | |
584 | put_task_struct(child); | |
585 | out: | |
586 | unlock_kernel(); | |
587 | return ret; | |
588 | } | |
589 | #endif /* __ARCH_SYS_PTRACE */ | |
76647323 AD |
590 | |
591 | int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) | |
592 | { | |
593 | unsigned long tmp; | |
594 | int copied; | |
595 | ||
596 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
597 | if (copied != sizeof(tmp)) | |
598 | return -EIO; | |
599 | return put_user(tmp, (unsigned long __user *)data); | |
600 | } | |
f284ce72 AD |
601 | |
602 | int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) | |
603 | { | |
604 | int copied; | |
605 | ||
606 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
607 | return (copied == sizeof(data)) ? 0 : -EIO; | |
608 | } | |
032d82d9 RM |
609 | |
610 | #ifdef CONFIG_COMPAT | |
611 | #include <linux/compat.h> | |
612 | ||
613 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
614 | compat_ulong_t addr, compat_ulong_t data) | |
615 | { | |
616 | compat_ulong_t __user *datap = compat_ptr(data); | |
617 | compat_ulong_t word; | |
618 | int ret; | |
619 | ||
620 | switch (request) { | |
621 | case PTRACE_PEEKTEXT: | |
622 | case PTRACE_PEEKDATA: | |
623 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
624 | if (ret != sizeof(word)) | |
625 | ret = -EIO; | |
626 | else | |
627 | ret = put_user(word, datap); | |
628 | break; | |
629 | ||
630 | case PTRACE_POKETEXT: | |
631 | case PTRACE_POKEDATA: | |
632 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
633 | ret = (ret != sizeof(data) ? -EIO : 0); | |
634 | break; | |
635 | ||
636 | case PTRACE_GETEVENTMSG: | |
637 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
638 | break; | |
639 | ||
640 | default: | |
641 | ret = ptrace_request(child, request, addr, data); | |
642 | } | |
643 | ||
644 | return ret; | |
645 | } | |
c269f196 RM |
646 | |
647 | #ifdef __ARCH_WANT_COMPAT_SYS_PTRACE | |
648 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, | |
649 | compat_long_t addr, compat_long_t data) | |
650 | { | |
651 | struct task_struct *child; | |
652 | long ret; | |
653 | ||
654 | /* | |
655 | * This lock_kernel fixes a subtle race with suid exec | |
656 | */ | |
657 | lock_kernel(); | |
658 | if (request == PTRACE_TRACEME) { | |
659 | ret = ptrace_traceme(); | |
660 | goto out; | |
661 | } | |
662 | ||
663 | child = ptrace_get_task_struct(pid); | |
664 | if (IS_ERR(child)) { | |
665 | ret = PTR_ERR(child); | |
666 | goto out; | |
667 | } | |
668 | ||
669 | if (request == PTRACE_ATTACH) { | |
670 | ret = ptrace_attach(child); | |
671 | /* | |
672 | * Some architectures need to do book-keeping after | |
673 | * a ptrace attach. | |
674 | */ | |
675 | if (!ret) | |
676 | arch_ptrace_attach(child); | |
677 | goto out_put_task_struct; | |
678 | } | |
679 | ||
680 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
681 | if (!ret) | |
682 | ret = compat_arch_ptrace(child, request, addr, data); | |
683 | ||
684 | out_put_task_struct: | |
685 | put_task_struct(child); | |
686 | out: | |
687 | unlock_kernel(); | |
688 | return ret; | |
689 | } | |
690 | #endif /* __ARCH_WANT_COMPAT_SYS_PTRACE */ | |
691 | ||
032d82d9 | 692 | #endif /* CONFIG_COMPAT */ |