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Commit | Line | Data |
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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); | |
c0c0b649 | 102 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
1da177e4 | 103 | ret = 0; |
c0c0b649 ON |
104 | /* |
105 | * child->sighand can't be NULL, release_task() | |
106 | * does ptrace_unlink() before __exit_signal(). | |
107 | */ | |
1da177e4 | 108 | spin_lock_irq(&child->sighand->siglock); |
d9ae90ac | 109 | if (task_is_stopped(child)) |
1da177e4 | 110 | child->state = TASK_TRACED; |
d9ae90ac | 111 | else if (!task_is_traced(child) && !kill) |
1da177e4 | 112 | ret = -ESRCH; |
1da177e4 LT |
113 | spin_unlock_irq(&child->sighand->siglock); |
114 | } | |
115 | read_unlock(&tasklist_lock); | |
116 | ||
d9ae90ac | 117 | if (!ret && !kill) |
1da177e4 | 118 | wait_task_inactive(child); |
1da177e4 LT |
119 | |
120 | /* All systems go.. */ | |
121 | return ret; | |
122 | } | |
123 | ||
831830b5 | 124 | int __ptrace_may_attach(struct task_struct *task) |
ab8d11be | 125 | { |
df26c40e EB |
126 | /* May we inspect the given task? |
127 | * This check is used both for attaching with ptrace | |
128 | * and for allowing access to sensitive information in /proc. | |
129 | * | |
130 | * ptrace_attach denies several cases that /proc allows | |
131 | * because setting up the necessary parent/child relationship | |
132 | * or halting the specified task is impossible. | |
133 | */ | |
134 | int dumpable = 0; | |
135 | /* Don't let security modules deny introspection */ | |
136 | if (task == current) | |
137 | return 0; | |
ab8d11be MS |
138 | if (((current->uid != task->euid) || |
139 | (current->uid != task->suid) || | |
140 | (current->uid != task->uid) || | |
141 | (current->gid != task->egid) || | |
142 | (current->gid != task->sgid) || | |
143 | (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) | |
144 | return -EPERM; | |
145 | smp_rmb(); | |
df26c40e | 146 | if (task->mm) |
6c5d5238 | 147 | dumpable = get_dumpable(task->mm); |
df26c40e | 148 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
ab8d11be MS |
149 | return -EPERM; |
150 | ||
151 | return security_ptrace(current, task); | |
152 | } | |
153 | ||
154 | int ptrace_may_attach(struct task_struct *task) | |
155 | { | |
156 | int err; | |
157 | task_lock(task); | |
831830b5 | 158 | err = __ptrace_may_attach(task); |
ab8d11be MS |
159 | task_unlock(task); |
160 | return !err; | |
161 | } | |
162 | ||
1da177e4 LT |
163 | int ptrace_attach(struct task_struct *task) |
164 | { | |
165 | int retval; | |
6175ecfe | 166 | unsigned long flags; |
f5b40e36 | 167 | |
a5cb013d AV |
168 | audit_ptrace(task); |
169 | ||
1da177e4 LT |
170 | retval = -EPERM; |
171 | if (task->pid <= 1) | |
f5b40e36 | 172 | goto out; |
bac0abd6 | 173 | if (same_thread_group(task, current)) |
f5b40e36 LT |
174 | goto out; |
175 | ||
f358166a LT |
176 | repeat: |
177 | /* | |
178 | * Nasty, nasty. | |
179 | * | |
180 | * We want to hold both the task-lock and the | |
181 | * tasklist_lock for writing at the same time. | |
182 | * But that's against the rules (tasklist_lock | |
183 | * is taken for reading by interrupts on other | |
184 | * cpu's that may have task_lock). | |
185 | */ | |
f5b40e36 | 186 | task_lock(task); |
6175ecfe | 187 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { |
f358166a LT |
188 | task_unlock(task); |
189 | do { | |
190 | cpu_relax(); | |
191 | } while (!write_can_lock(&tasklist_lock)); | |
192 | goto repeat; | |
193 | } | |
f5b40e36 | 194 | |
df26c40e EB |
195 | if (!task->mm) |
196 | goto bad; | |
1da177e4 LT |
197 | /* the same process cannot be attached many times */ |
198 | if (task->ptrace & PT_PTRACED) | |
199 | goto bad; | |
b8c9a187 | 200 | retval = __ptrace_may_attach(task); |
1da177e4 LT |
201 | if (retval) |
202 | goto bad; | |
203 | ||
204 | /* Go */ | |
6b39c7bf | 205 | task->ptrace |= PT_PTRACED; |
1da177e4 LT |
206 | if (capable(CAP_SYS_PTRACE)) |
207 | task->ptrace |= PT_PTRACE_CAP; | |
1da177e4 | 208 | |
1da177e4 | 209 | __ptrace_link(task, current); |
1da177e4 LT |
210 | |
211 | force_sig_specific(SIGSTOP, task); | |
1da177e4 LT |
212 | |
213 | bad: | |
6175ecfe | 214 | write_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 | 215 | task_unlock(task); |
f5b40e36 | 216 | out: |
1da177e4 LT |
217 | return retval; |
218 | } | |
219 | ||
d5f70c00 | 220 | static inline void __ptrace_detach(struct task_struct *child, unsigned int data) |
5ecfbae0 ON |
221 | { |
222 | child->exit_code = data; | |
223 | /* .. re-parent .. */ | |
224 | __ptrace_unlink(child); | |
225 | /* .. and wake it up. */ | |
226 | if (child->exit_state != EXIT_ZOMBIE) | |
227 | wake_up_process(child); | |
228 | } | |
229 | ||
1da177e4 LT |
230 | int ptrace_detach(struct task_struct *child, unsigned int data) |
231 | { | |
7ed20e1a | 232 | if (!valid_signal(data)) |
5ecfbae0 | 233 | return -EIO; |
1da177e4 LT |
234 | |
235 | /* Architecture-specific hardware disable .. */ | |
236 | ptrace_disable(child); | |
7d941432 | 237 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 238 | |
1da177e4 | 239 | write_lock_irq(&tasklist_lock); |
d5f70c00 | 240 | /* protect against de_thread()->release_task() */ |
5ecfbae0 ON |
241 | if (child->ptrace) |
242 | __ptrace_detach(child, data); | |
1da177e4 LT |
243 | write_unlock_irq(&tasklist_lock); |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
1da177e4 LT |
248 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
249 | { | |
250 | int copied = 0; | |
251 | ||
252 | while (len > 0) { | |
253 | char buf[128]; | |
254 | int this_len, retval; | |
255 | ||
256 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
257 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
258 | if (!retval) { | |
259 | if (copied) | |
260 | break; | |
261 | return -EIO; | |
262 | } | |
263 | if (copy_to_user(dst, buf, retval)) | |
264 | return -EFAULT; | |
265 | copied += retval; | |
266 | src += retval; | |
267 | dst += retval; | |
268 | len -= retval; | |
269 | } | |
270 | return copied; | |
271 | } | |
272 | ||
273 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
274 | { | |
275 | int copied = 0; | |
276 | ||
277 | while (len > 0) { | |
278 | char buf[128]; | |
279 | int this_len, retval; | |
280 | ||
281 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
282 | if (copy_from_user(buf, src, this_len)) | |
283 | return -EFAULT; | |
284 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
285 | if (!retval) { | |
286 | if (copied) | |
287 | break; | |
288 | return -EIO; | |
289 | } | |
290 | copied += retval; | |
291 | src += retval; | |
292 | dst += retval; | |
293 | len -= retval; | |
294 | } | |
295 | return copied; | |
296 | } | |
297 | ||
298 | static int ptrace_setoptions(struct task_struct *child, long data) | |
299 | { | |
300 | child->ptrace &= ~PT_TRACE_MASK; | |
301 | ||
302 | if (data & PTRACE_O_TRACESYSGOOD) | |
303 | child->ptrace |= PT_TRACESYSGOOD; | |
304 | ||
305 | if (data & PTRACE_O_TRACEFORK) | |
306 | child->ptrace |= PT_TRACE_FORK; | |
307 | ||
308 | if (data & PTRACE_O_TRACEVFORK) | |
309 | child->ptrace |= PT_TRACE_VFORK; | |
310 | ||
311 | if (data & PTRACE_O_TRACECLONE) | |
312 | child->ptrace |= PT_TRACE_CLONE; | |
313 | ||
314 | if (data & PTRACE_O_TRACEEXEC) | |
315 | child->ptrace |= PT_TRACE_EXEC; | |
316 | ||
317 | if (data & PTRACE_O_TRACEVFORKDONE) | |
318 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
319 | ||
320 | if (data & PTRACE_O_TRACEEXIT) | |
321 | child->ptrace |= PT_TRACE_EXIT; | |
322 | ||
323 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
324 | } | |
325 | ||
326 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) | |
327 | { | |
328 | siginfo_t lastinfo; | |
329 | int error = -ESRCH; | |
330 | ||
331 | read_lock(&tasklist_lock); | |
332 | if (likely(child->sighand != NULL)) { | |
333 | error = -EINVAL; | |
334 | spin_lock_irq(&child->sighand->siglock); | |
335 | if (likely(child->last_siginfo != NULL)) { | |
336 | lastinfo = *child->last_siginfo; | |
337 | error = 0; | |
338 | } | |
339 | spin_unlock_irq(&child->sighand->siglock); | |
340 | } | |
341 | read_unlock(&tasklist_lock); | |
342 | if (!error) | |
343 | return copy_siginfo_to_user(data, &lastinfo); | |
344 | return error; | |
345 | } | |
346 | ||
347 | static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) | |
348 | { | |
349 | siginfo_t newinfo; | |
350 | int error = -ESRCH; | |
351 | ||
352 | if (copy_from_user(&newinfo, data, sizeof (siginfo_t))) | |
353 | return -EFAULT; | |
354 | ||
355 | read_lock(&tasklist_lock); | |
356 | if (likely(child->sighand != NULL)) { | |
357 | error = -EINVAL; | |
358 | spin_lock_irq(&child->sighand->siglock); | |
359 | if (likely(child->last_siginfo != NULL)) { | |
360 | *child->last_siginfo = newinfo; | |
361 | error = 0; | |
362 | } | |
363 | spin_unlock_irq(&child->sighand->siglock); | |
364 | } | |
365 | read_unlock(&tasklist_lock); | |
366 | return error; | |
367 | } | |
368 | ||
36df29d7 RM |
369 | |
370 | #ifdef PTRACE_SINGLESTEP | |
371 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
372 | #else | |
373 | #define is_singlestep(request) 0 | |
374 | #endif | |
375 | ||
5b88abbf RM |
376 | #ifdef PTRACE_SINGLEBLOCK |
377 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
378 | #else | |
379 | #define is_singleblock(request) 0 | |
380 | #endif | |
381 | ||
36df29d7 RM |
382 | #ifdef PTRACE_SYSEMU |
383 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
384 | #else | |
385 | #define is_sysemu_singlestep(request) 0 | |
386 | #endif | |
387 | ||
388 | static int ptrace_resume(struct task_struct *child, long request, long data) | |
389 | { | |
390 | if (!valid_signal(data)) | |
391 | return -EIO; | |
392 | ||
393 | if (request == PTRACE_SYSCALL) | |
394 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
395 | else | |
396 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
397 | ||
398 | #ifdef TIF_SYSCALL_EMU | |
399 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
400 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
401 | else | |
402 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
403 | #endif | |
404 | ||
5b88abbf RM |
405 | if (is_singleblock(request)) { |
406 | if (unlikely(!arch_has_block_step())) | |
407 | return -EIO; | |
408 | user_enable_block_step(child); | |
409 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
410 | if (unlikely(!arch_has_single_step())) |
411 | return -EIO; | |
412 | user_enable_single_step(child); | |
413 | } | |
414 | else | |
415 | user_disable_single_step(child); | |
416 | ||
417 | child->exit_code = data; | |
418 | wake_up_process(child); | |
419 | ||
420 | return 0; | |
421 | } | |
422 | ||
1da177e4 LT |
423 | int ptrace_request(struct task_struct *child, long request, |
424 | long addr, long data) | |
425 | { | |
426 | int ret = -EIO; | |
427 | ||
428 | switch (request) { | |
16c3e389 RM |
429 | case PTRACE_PEEKTEXT: |
430 | case PTRACE_PEEKDATA: | |
431 | return generic_ptrace_peekdata(child, addr, data); | |
432 | case PTRACE_POKETEXT: | |
433 | case PTRACE_POKEDATA: | |
434 | return generic_ptrace_pokedata(child, addr, data); | |
435 | ||
1da177e4 LT |
436 | #ifdef PTRACE_OLDSETOPTIONS |
437 | case PTRACE_OLDSETOPTIONS: | |
438 | #endif | |
439 | case PTRACE_SETOPTIONS: | |
440 | ret = ptrace_setoptions(child, data); | |
441 | break; | |
442 | case PTRACE_GETEVENTMSG: | |
443 | ret = put_user(child->ptrace_message, (unsigned long __user *) data); | |
444 | break; | |
445 | case PTRACE_GETSIGINFO: | |
446 | ret = ptrace_getsiginfo(child, (siginfo_t __user *) data); | |
447 | break; | |
448 | case PTRACE_SETSIGINFO: | |
449 | ret = ptrace_setsiginfo(child, (siginfo_t __user *) data); | |
450 | break; | |
1bcf5482 AD |
451 | case PTRACE_DETACH: /* detach a process that was attached. */ |
452 | ret = ptrace_detach(child, data); | |
453 | break; | |
36df29d7 RM |
454 | |
455 | #ifdef PTRACE_SINGLESTEP | |
456 | case PTRACE_SINGLESTEP: | |
457 | #endif | |
5b88abbf RM |
458 | #ifdef PTRACE_SINGLEBLOCK |
459 | case PTRACE_SINGLEBLOCK: | |
460 | #endif | |
36df29d7 RM |
461 | #ifdef PTRACE_SYSEMU |
462 | case PTRACE_SYSEMU: | |
463 | case PTRACE_SYSEMU_SINGLESTEP: | |
464 | #endif | |
465 | case PTRACE_SYSCALL: | |
466 | case PTRACE_CONT: | |
467 | return ptrace_resume(child, request, data); | |
468 | ||
469 | case PTRACE_KILL: | |
470 | if (child->exit_state) /* already dead */ | |
471 | return 0; | |
472 | return ptrace_resume(child, request, SIGKILL); | |
473 | ||
1da177e4 LT |
474 | default: |
475 | break; | |
476 | } | |
477 | ||
478 | return ret; | |
479 | } | |
481bed45 | 480 | |
6b9c7ed8 CH |
481 | /** |
482 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
483 | * | |
484 | * Performs checks and sets PT_PTRACED. | |
485 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
486 | */ | |
487 | int ptrace_traceme(void) | |
481bed45 | 488 | { |
f5b40e36 | 489 | int ret = -EPERM; |
481bed45 CH |
490 | |
491 | /* | |
6b9c7ed8 CH |
492 | * Are we already being traced? |
493 | */ | |
f5b40e36 LT |
494 | task_lock(current); |
495 | if (!(current->ptrace & PT_PTRACED)) { | |
496 | ret = security_ptrace(current->parent, current); | |
497 | /* | |
498 | * Set the ptrace bit in the process ptrace flags. | |
499 | */ | |
500 | if (!ret) | |
501 | current->ptrace |= PT_PTRACED; | |
502 | } | |
503 | task_unlock(current); | |
504 | return ret; | |
6b9c7ed8 | 505 | } |
481bed45 | 506 | |
6b9c7ed8 CH |
507 | /** |
508 | * ptrace_get_task_struct -- grab a task struct reference for ptrace | |
509 | * @pid: process id to grab a task_struct reference of | |
510 | * | |
511 | * This function is a helper for ptrace implementations. It checks | |
512 | * permissions and then grabs a task struct for use of the actual | |
513 | * ptrace implementation. | |
514 | * | |
515 | * Returns the task_struct for @pid or an ERR_PTR() on failure. | |
516 | */ | |
517 | struct task_struct *ptrace_get_task_struct(pid_t pid) | |
518 | { | |
519 | struct task_struct *child; | |
481bed45 CH |
520 | |
521 | /* | |
6b9c7ed8 | 522 | * Tracing init is not allowed. |
481bed45 CH |
523 | */ |
524 | if (pid == 1) | |
6b9c7ed8 | 525 | return ERR_PTR(-EPERM); |
481bed45 | 526 | |
481bed45 | 527 | read_lock(&tasklist_lock); |
228ebcbe | 528 | child = find_task_by_vpid(pid); |
481bed45 CH |
529 | if (child) |
530 | get_task_struct(child); | |
f400e198 | 531 | |
481bed45 CH |
532 | read_unlock(&tasklist_lock); |
533 | if (!child) | |
6b9c7ed8 CH |
534 | return ERR_PTR(-ESRCH); |
535 | return child; | |
481bed45 CH |
536 | } |
537 | ||
0ac15559 CH |
538 | #ifndef arch_ptrace_attach |
539 | #define arch_ptrace_attach(child) do { } while (0) | |
540 | #endif | |
541 | ||
6b9c7ed8 | 542 | #ifndef __ARCH_SYS_PTRACE |
481bed45 CH |
543 | asmlinkage long sys_ptrace(long request, long pid, long addr, long data) |
544 | { | |
545 | struct task_struct *child; | |
546 | long ret; | |
547 | ||
548 | /* | |
549 | * This lock_kernel fixes a subtle race with suid exec | |
550 | */ | |
551 | lock_kernel(); | |
6b9c7ed8 CH |
552 | if (request == PTRACE_TRACEME) { |
553 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
554 | if (!ret) |
555 | arch_ptrace_attach(current); | |
481bed45 | 556 | goto out; |
6b9c7ed8 CH |
557 | } |
558 | ||
559 | child = ptrace_get_task_struct(pid); | |
560 | if (IS_ERR(child)) { | |
561 | ret = PTR_ERR(child); | |
562 | goto out; | |
563 | } | |
481bed45 CH |
564 | |
565 | if (request == PTRACE_ATTACH) { | |
566 | ret = ptrace_attach(child); | |
0ac15559 CH |
567 | /* |
568 | * Some architectures need to do book-keeping after | |
569 | * a ptrace attach. | |
570 | */ | |
571 | if (!ret) | |
572 | arch_ptrace_attach(child); | |
005f18df | 573 | goto out_put_task_struct; |
481bed45 CH |
574 | } |
575 | ||
576 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
577 | if (ret < 0) | |
578 | goto out_put_task_struct; | |
579 | ||
580 | ret = arch_ptrace(child, request, addr, data); | |
581 | if (ret < 0) | |
582 | goto out_put_task_struct; | |
583 | ||
584 | out_put_task_struct: | |
585 | put_task_struct(child); | |
586 | out: | |
587 | unlock_kernel(); | |
588 | return ret; | |
589 | } | |
590 | #endif /* __ARCH_SYS_PTRACE */ | |
76647323 AD |
591 | |
592 | int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) | |
593 | { | |
594 | unsigned long tmp; | |
595 | int copied; | |
596 | ||
597 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
598 | if (copied != sizeof(tmp)) | |
599 | return -EIO; | |
600 | return put_user(tmp, (unsigned long __user *)data); | |
601 | } | |
f284ce72 AD |
602 | |
603 | int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) | |
604 | { | |
605 | int copied; | |
606 | ||
607 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
608 | return (copied == sizeof(data)) ? 0 : -EIO; | |
609 | } | |
032d82d9 RM |
610 | |
611 | #ifdef CONFIG_COMPAT | |
612 | #include <linux/compat.h> | |
613 | ||
614 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
615 | compat_ulong_t addr, compat_ulong_t data) | |
616 | { | |
617 | compat_ulong_t __user *datap = compat_ptr(data); | |
618 | compat_ulong_t word; | |
619 | int ret; | |
620 | ||
621 | switch (request) { | |
622 | case PTRACE_PEEKTEXT: | |
623 | case PTRACE_PEEKDATA: | |
624 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
625 | if (ret != sizeof(word)) | |
626 | ret = -EIO; | |
627 | else | |
628 | ret = put_user(word, datap); | |
629 | break; | |
630 | ||
631 | case PTRACE_POKETEXT: | |
632 | case PTRACE_POKEDATA: | |
633 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
634 | ret = (ret != sizeof(data) ? -EIO : 0); | |
635 | break; | |
636 | ||
637 | case PTRACE_GETEVENTMSG: | |
638 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
639 | break; | |
640 | ||
641 | default: | |
642 | ret = ptrace_request(child, request, addr, data); | |
643 | } | |
644 | ||
645 | return ret; | |
646 | } | |
c269f196 RM |
647 | |
648 | #ifdef __ARCH_WANT_COMPAT_SYS_PTRACE | |
649 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, | |
650 | compat_long_t addr, compat_long_t data) | |
651 | { | |
652 | struct task_struct *child; | |
653 | long ret; | |
654 | ||
655 | /* | |
656 | * This lock_kernel fixes a subtle race with suid exec | |
657 | */ | |
658 | lock_kernel(); | |
659 | if (request == PTRACE_TRACEME) { | |
660 | ret = ptrace_traceme(); | |
661 | goto out; | |
662 | } | |
663 | ||
664 | child = ptrace_get_task_struct(pid); | |
665 | if (IS_ERR(child)) { | |
666 | ret = PTR_ERR(child); | |
667 | goto out; | |
668 | } | |
669 | ||
670 | if (request == PTRACE_ATTACH) { | |
671 | ret = ptrace_attach(child); | |
672 | /* | |
673 | * Some architectures need to do book-keeping after | |
674 | * a ptrace attach. | |
675 | */ | |
676 | if (!ret) | |
677 | arch_ptrace_attach(child); | |
678 | goto out_put_task_struct; | |
679 | } | |
680 | ||
681 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
682 | if (!ret) | |
683 | ret = compat_arch_ptrace(child, request, addr, data); | |
684 | ||
685 | out_put_task_struct: | |
686 | put_task_struct(child); | |
687 | out: | |
688 | unlock_kernel(); | |
689 | return ret; | |
690 | } | |
691 | #endif /* __ARCH_WANT_COMPAT_SYS_PTRACE */ | |
692 | ||
032d82d9 | 693 | #endif /* CONFIG_COMPAT */ |