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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 | { |
f470021a RM |
36 | BUG_ON(!list_empty(&child->ptrace_entry)); |
37 | list_add(&child->ptrace_entry, &new_parent->ptraced); | |
1da177e4 | 38 | child->parent = new_parent; |
1da177e4 LT |
39 | } |
40 | ||
41 | /* | |
42 | * Turn a tracing stop into a normal stop now, since with no tracer there | |
43 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a | |
44 | * signal sent that would resume the child, but didn't because it was in | |
45 | * TASK_TRACED, resume it now. | |
46 | * Requires that irqs be disabled. | |
47 | */ | |
b747c8c1 | 48 | static void ptrace_untrace(struct task_struct *child) |
1da177e4 LT |
49 | { |
50 | spin_lock(&child->sighand->siglock); | |
6618a3e2 | 51 | if (task_is_traced(child)) { |
1da177e4 | 52 | if (child->signal->flags & SIGNAL_STOP_STOPPED) { |
d9ae90ac | 53 | __set_task_state(child, TASK_STOPPED); |
1da177e4 LT |
54 | } else { |
55 | signal_wake_up(child, 1); | |
56 | } | |
57 | } | |
58 | spin_unlock(&child->sighand->siglock); | |
59 | } | |
60 | ||
61 | /* | |
62 | * unptrace a task: move it back to its original parent and | |
63 | * remove it from the ptrace list. | |
64 | * | |
65 | * Must be called with the tasklist lock write-held. | |
66 | */ | |
36c8b586 | 67 | void __ptrace_unlink(struct task_struct *child) |
1da177e4 | 68 | { |
5ecfbae0 ON |
69 | BUG_ON(!child->ptrace); |
70 | ||
1da177e4 | 71 | child->ptrace = 0; |
f470021a RM |
72 | child->parent = child->real_parent; |
73 | list_del_init(&child->ptrace_entry); | |
1da177e4 | 74 | |
6618a3e2 | 75 | if (task_is_traced(child)) |
e57a5059 | 76 | ptrace_untrace(child); |
1da177e4 LT |
77 | } |
78 | ||
79 | /* | |
80 | * Check that we have indeed attached to the thing.. | |
81 | */ | |
82 | int ptrace_check_attach(struct task_struct *child, int kill) | |
83 | { | |
84 | int ret = -ESRCH; | |
85 | ||
86 | /* | |
87 | * We take the read lock around doing both checks to close a | |
88 | * possible race where someone else was tracing our child and | |
89 | * detached between these two checks. After this locked check, | |
90 | * we are sure that this is our traced child and that can only | |
91 | * be changed by us so it's not changing right after this. | |
92 | */ | |
93 | read_lock(&tasklist_lock); | |
c0c0b649 | 94 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
1da177e4 | 95 | ret = 0; |
c0c0b649 ON |
96 | /* |
97 | * child->sighand can't be NULL, release_task() | |
98 | * does ptrace_unlink() before __exit_signal(). | |
99 | */ | |
1da177e4 | 100 | spin_lock_irq(&child->sighand->siglock); |
d9ae90ac | 101 | if (task_is_stopped(child)) |
1da177e4 | 102 | child->state = TASK_TRACED; |
d9ae90ac | 103 | else if (!task_is_traced(child) && !kill) |
1da177e4 | 104 | ret = -ESRCH; |
1da177e4 LT |
105 | spin_unlock_irq(&child->sighand->siglock); |
106 | } | |
107 | read_unlock(&tasklist_lock); | |
108 | ||
d9ae90ac | 109 | if (!ret && !kill) |
85ba2d86 | 110 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
1da177e4 LT |
111 | |
112 | /* All systems go.. */ | |
113 | return ret; | |
114 | } | |
115 | ||
006ebb40 | 116 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be | 117 | { |
b6dff3ec DH |
118 | struct cred *cred = current->cred, *tcred = task->cred; |
119 | ||
df26c40e EB |
120 | /* May we inspect the given task? |
121 | * This check is used both for attaching with ptrace | |
122 | * and for allowing access to sensitive information in /proc. | |
123 | * | |
124 | * ptrace_attach denies several cases that /proc allows | |
125 | * because setting up the necessary parent/child relationship | |
126 | * or halting the specified task is impossible. | |
127 | */ | |
b6dff3ec DH |
128 | uid_t uid = cred->uid; |
129 | gid_t gid = cred->gid; | |
df26c40e EB |
130 | int dumpable = 0; |
131 | /* Don't let security modules deny introspection */ | |
132 | if (task == current) | |
133 | return 0; | |
b6dff3ec DH |
134 | if ((uid != tcred->euid || |
135 | uid != tcred->suid || | |
136 | uid != tcred->uid || | |
137 | gid != tcred->egid || | |
138 | gid != tcred->sgid || | |
139 | gid != tcred->gid) && !capable(CAP_SYS_PTRACE)) | |
ab8d11be MS |
140 | return -EPERM; |
141 | smp_rmb(); | |
df26c40e | 142 | if (task->mm) |
6c5d5238 | 143 | dumpable = get_dumpable(task->mm); |
df26c40e | 144 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
ab8d11be MS |
145 | return -EPERM; |
146 | ||
5cd9c58f | 147 | return security_ptrace_may_access(task, mode); |
ab8d11be MS |
148 | } |
149 | ||
006ebb40 | 150 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
ab8d11be MS |
151 | { |
152 | int err; | |
153 | task_lock(task); | |
006ebb40 | 154 | err = __ptrace_may_access(task, mode); |
ab8d11be | 155 | task_unlock(task); |
006ebb40 | 156 | return (!err ? true : false); |
ab8d11be MS |
157 | } |
158 | ||
1da177e4 LT |
159 | int ptrace_attach(struct task_struct *task) |
160 | { | |
161 | int retval; | |
6175ecfe | 162 | unsigned long flags; |
f5b40e36 | 163 | |
a5cb013d AV |
164 | audit_ptrace(task); |
165 | ||
1da177e4 | 166 | retval = -EPERM; |
bac0abd6 | 167 | if (same_thread_group(task, current)) |
f5b40e36 LT |
168 | goto out; |
169 | ||
f358166a LT |
170 | repeat: |
171 | /* | |
172 | * Nasty, nasty. | |
173 | * | |
174 | * We want to hold both the task-lock and the | |
175 | * tasklist_lock for writing at the same time. | |
176 | * But that's against the rules (tasklist_lock | |
177 | * is taken for reading by interrupts on other | |
178 | * cpu's that may have task_lock). | |
179 | */ | |
f5b40e36 | 180 | task_lock(task); |
6175ecfe | 181 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { |
f358166a LT |
182 | task_unlock(task); |
183 | do { | |
184 | cpu_relax(); | |
185 | } while (!write_can_lock(&tasklist_lock)); | |
186 | goto repeat; | |
187 | } | |
f5b40e36 | 188 | |
df26c40e EB |
189 | if (!task->mm) |
190 | goto bad; | |
1da177e4 LT |
191 | /* the same process cannot be attached many times */ |
192 | if (task->ptrace & PT_PTRACED) | |
193 | goto bad; | |
006ebb40 | 194 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
1da177e4 LT |
195 | if (retval) |
196 | goto bad; | |
197 | ||
198 | /* Go */ | |
6b39c7bf | 199 | task->ptrace |= PT_PTRACED; |
1da177e4 LT |
200 | if (capable(CAP_SYS_PTRACE)) |
201 | task->ptrace |= PT_PTRACE_CAP; | |
1da177e4 | 202 | |
1da177e4 | 203 | __ptrace_link(task, current); |
1da177e4 | 204 | |
33e9fc7d | 205 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
1da177e4 | 206 | bad: |
6175ecfe | 207 | write_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 | 208 | task_unlock(task); |
f5b40e36 | 209 | out: |
1da177e4 LT |
210 | return retval; |
211 | } | |
212 | ||
d5f70c00 | 213 | static inline void __ptrace_detach(struct task_struct *child, unsigned int data) |
5ecfbae0 ON |
214 | { |
215 | child->exit_code = data; | |
216 | /* .. re-parent .. */ | |
217 | __ptrace_unlink(child); | |
218 | /* .. and wake it up. */ | |
219 | if (child->exit_state != EXIT_ZOMBIE) | |
220 | wake_up_process(child); | |
221 | } | |
222 | ||
1da177e4 LT |
223 | int ptrace_detach(struct task_struct *child, unsigned int data) |
224 | { | |
7ed20e1a | 225 | if (!valid_signal(data)) |
5ecfbae0 | 226 | return -EIO; |
1da177e4 LT |
227 | |
228 | /* Architecture-specific hardware disable .. */ | |
229 | ptrace_disable(child); | |
7d941432 | 230 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
1da177e4 | 231 | |
1da177e4 | 232 | write_lock_irq(&tasklist_lock); |
d5f70c00 | 233 | /* protect against de_thread()->release_task() */ |
5ecfbae0 ON |
234 | if (child->ptrace) |
235 | __ptrace_detach(child, data); | |
1da177e4 LT |
236 | write_unlock_irq(&tasklist_lock); |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
1da177e4 LT |
241 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
242 | { | |
243 | int copied = 0; | |
244 | ||
245 | while (len > 0) { | |
246 | char buf[128]; | |
247 | int this_len, retval; | |
248 | ||
249 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
250 | retval = access_process_vm(tsk, src, buf, this_len, 0); | |
251 | if (!retval) { | |
252 | if (copied) | |
253 | break; | |
254 | return -EIO; | |
255 | } | |
256 | if (copy_to_user(dst, buf, retval)) | |
257 | return -EFAULT; | |
258 | copied += retval; | |
259 | src += retval; | |
260 | dst += retval; | |
261 | len -= retval; | |
262 | } | |
263 | return copied; | |
264 | } | |
265 | ||
266 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) | |
267 | { | |
268 | int copied = 0; | |
269 | ||
270 | while (len > 0) { | |
271 | char buf[128]; | |
272 | int this_len, retval; | |
273 | ||
274 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; | |
275 | if (copy_from_user(buf, src, this_len)) | |
276 | return -EFAULT; | |
277 | retval = access_process_vm(tsk, dst, buf, this_len, 1); | |
278 | if (!retval) { | |
279 | if (copied) | |
280 | break; | |
281 | return -EIO; | |
282 | } | |
283 | copied += retval; | |
284 | src += retval; | |
285 | dst += retval; | |
286 | len -= retval; | |
287 | } | |
288 | return copied; | |
289 | } | |
290 | ||
291 | static int ptrace_setoptions(struct task_struct *child, long data) | |
292 | { | |
293 | child->ptrace &= ~PT_TRACE_MASK; | |
294 | ||
295 | if (data & PTRACE_O_TRACESYSGOOD) | |
296 | child->ptrace |= PT_TRACESYSGOOD; | |
297 | ||
298 | if (data & PTRACE_O_TRACEFORK) | |
299 | child->ptrace |= PT_TRACE_FORK; | |
300 | ||
301 | if (data & PTRACE_O_TRACEVFORK) | |
302 | child->ptrace |= PT_TRACE_VFORK; | |
303 | ||
304 | if (data & PTRACE_O_TRACECLONE) | |
305 | child->ptrace |= PT_TRACE_CLONE; | |
306 | ||
307 | if (data & PTRACE_O_TRACEEXEC) | |
308 | child->ptrace |= PT_TRACE_EXEC; | |
309 | ||
310 | if (data & PTRACE_O_TRACEVFORKDONE) | |
311 | child->ptrace |= PT_TRACE_VFORK_DONE; | |
312 | ||
313 | if (data & PTRACE_O_TRACEEXIT) | |
314 | child->ptrace |= PT_TRACE_EXIT; | |
315 | ||
316 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; | |
317 | } | |
318 | ||
e16b2781 | 319 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
1da177e4 | 320 | { |
1da177e4 LT |
321 | int error = -ESRCH; |
322 | ||
323 | read_lock(&tasklist_lock); | |
324 | if (likely(child->sighand != NULL)) { | |
325 | error = -EINVAL; | |
326 | spin_lock_irq(&child->sighand->siglock); | |
327 | if (likely(child->last_siginfo != NULL)) { | |
e16b2781 | 328 | *info = *child->last_siginfo; |
1da177e4 LT |
329 | error = 0; |
330 | } | |
331 | spin_unlock_irq(&child->sighand->siglock); | |
332 | } | |
333 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
334 | return error; |
335 | } | |
336 | ||
e16b2781 | 337 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
1da177e4 | 338 | { |
1da177e4 LT |
339 | int error = -ESRCH; |
340 | ||
1da177e4 LT |
341 | read_lock(&tasklist_lock); |
342 | if (likely(child->sighand != NULL)) { | |
343 | error = -EINVAL; | |
344 | spin_lock_irq(&child->sighand->siglock); | |
345 | if (likely(child->last_siginfo != NULL)) { | |
e16b2781 | 346 | *child->last_siginfo = *info; |
1da177e4 LT |
347 | error = 0; |
348 | } | |
349 | spin_unlock_irq(&child->sighand->siglock); | |
350 | } | |
351 | read_unlock(&tasklist_lock); | |
352 | return error; | |
353 | } | |
354 | ||
36df29d7 RM |
355 | |
356 | #ifdef PTRACE_SINGLESTEP | |
357 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) | |
358 | #else | |
359 | #define is_singlestep(request) 0 | |
360 | #endif | |
361 | ||
5b88abbf RM |
362 | #ifdef PTRACE_SINGLEBLOCK |
363 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) | |
364 | #else | |
365 | #define is_singleblock(request) 0 | |
366 | #endif | |
367 | ||
36df29d7 RM |
368 | #ifdef PTRACE_SYSEMU |
369 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) | |
370 | #else | |
371 | #define is_sysemu_singlestep(request) 0 | |
372 | #endif | |
373 | ||
374 | static int ptrace_resume(struct task_struct *child, long request, long data) | |
375 | { | |
376 | if (!valid_signal(data)) | |
377 | return -EIO; | |
378 | ||
379 | if (request == PTRACE_SYSCALL) | |
380 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
381 | else | |
382 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
383 | ||
384 | #ifdef TIF_SYSCALL_EMU | |
385 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) | |
386 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
387 | else | |
388 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); | |
389 | #endif | |
390 | ||
5b88abbf RM |
391 | if (is_singleblock(request)) { |
392 | if (unlikely(!arch_has_block_step())) | |
393 | return -EIO; | |
394 | user_enable_block_step(child); | |
395 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { | |
36df29d7 RM |
396 | if (unlikely(!arch_has_single_step())) |
397 | return -EIO; | |
398 | user_enable_single_step(child); | |
399 | } | |
400 | else | |
401 | user_disable_single_step(child); | |
402 | ||
403 | child->exit_code = data; | |
404 | wake_up_process(child); | |
405 | ||
406 | return 0; | |
407 | } | |
408 | ||
1da177e4 LT |
409 | int ptrace_request(struct task_struct *child, long request, |
410 | long addr, long data) | |
411 | { | |
412 | int ret = -EIO; | |
e16b2781 | 413 | siginfo_t siginfo; |
1da177e4 LT |
414 | |
415 | switch (request) { | |
16c3e389 RM |
416 | case PTRACE_PEEKTEXT: |
417 | case PTRACE_PEEKDATA: | |
418 | return generic_ptrace_peekdata(child, addr, data); | |
419 | case PTRACE_POKETEXT: | |
420 | case PTRACE_POKEDATA: | |
421 | return generic_ptrace_pokedata(child, addr, data); | |
422 | ||
1da177e4 LT |
423 | #ifdef PTRACE_OLDSETOPTIONS |
424 | case PTRACE_OLDSETOPTIONS: | |
425 | #endif | |
426 | case PTRACE_SETOPTIONS: | |
427 | ret = ptrace_setoptions(child, data); | |
428 | break; | |
429 | case PTRACE_GETEVENTMSG: | |
430 | ret = put_user(child->ptrace_message, (unsigned long __user *) data); | |
431 | break; | |
e16b2781 | 432 | |
1da177e4 | 433 | case PTRACE_GETSIGINFO: |
e16b2781 RM |
434 | ret = ptrace_getsiginfo(child, &siginfo); |
435 | if (!ret) | |
436 | ret = copy_siginfo_to_user((siginfo_t __user *) data, | |
437 | &siginfo); | |
1da177e4 | 438 | break; |
e16b2781 | 439 | |
1da177e4 | 440 | case PTRACE_SETSIGINFO: |
e16b2781 RM |
441 | if (copy_from_user(&siginfo, (siginfo_t __user *) data, |
442 | sizeof siginfo)) | |
443 | ret = -EFAULT; | |
444 | else | |
445 | ret = ptrace_setsiginfo(child, &siginfo); | |
1da177e4 | 446 | break; |
e16b2781 | 447 | |
1bcf5482 AD |
448 | case PTRACE_DETACH: /* detach a process that was attached. */ |
449 | ret = ptrace_detach(child, data); | |
450 | break; | |
36df29d7 RM |
451 | |
452 | #ifdef PTRACE_SINGLESTEP | |
453 | case PTRACE_SINGLESTEP: | |
454 | #endif | |
5b88abbf RM |
455 | #ifdef PTRACE_SINGLEBLOCK |
456 | case PTRACE_SINGLEBLOCK: | |
457 | #endif | |
36df29d7 RM |
458 | #ifdef PTRACE_SYSEMU |
459 | case PTRACE_SYSEMU: | |
460 | case PTRACE_SYSEMU_SINGLESTEP: | |
461 | #endif | |
462 | case PTRACE_SYSCALL: | |
463 | case PTRACE_CONT: | |
464 | return ptrace_resume(child, request, data); | |
465 | ||
466 | case PTRACE_KILL: | |
467 | if (child->exit_state) /* already dead */ | |
468 | return 0; | |
469 | return ptrace_resume(child, request, SIGKILL); | |
470 | ||
1da177e4 LT |
471 | default: |
472 | break; | |
473 | } | |
474 | ||
475 | return ret; | |
476 | } | |
481bed45 | 477 | |
6b9c7ed8 CH |
478 | /** |
479 | * ptrace_traceme -- helper for PTRACE_TRACEME | |
480 | * | |
481 | * Performs checks and sets PT_PTRACED. | |
482 | * Should be used by all ptrace implementations for PTRACE_TRACEME. | |
483 | */ | |
484 | int ptrace_traceme(void) | |
481bed45 | 485 | { |
f5b40e36 | 486 | int ret = -EPERM; |
481bed45 CH |
487 | |
488 | /* | |
6b9c7ed8 CH |
489 | * Are we already being traced? |
490 | */ | |
f470021a | 491 | repeat: |
f5b40e36 LT |
492 | task_lock(current); |
493 | if (!(current->ptrace & PT_PTRACED)) { | |
f470021a RM |
494 | /* |
495 | * See ptrace_attach() comments about the locking here. | |
496 | */ | |
497 | unsigned long flags; | |
498 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { | |
499 | task_unlock(current); | |
500 | do { | |
501 | cpu_relax(); | |
502 | } while (!write_can_lock(&tasklist_lock)); | |
503 | goto repeat; | |
504 | } | |
505 | ||
5cd9c58f | 506 | ret = security_ptrace_traceme(current->parent); |
f470021a | 507 | |
f5b40e36 LT |
508 | /* |
509 | * Set the ptrace bit in the process ptrace flags. | |
f470021a | 510 | * Then link us on our parent's ptraced list. |
f5b40e36 | 511 | */ |
f470021a | 512 | if (!ret) { |
f5b40e36 | 513 | current->ptrace |= PT_PTRACED; |
f470021a RM |
514 | __ptrace_link(current, current->real_parent); |
515 | } | |
516 | ||
517 | write_unlock_irqrestore(&tasklist_lock, flags); | |
f5b40e36 LT |
518 | } |
519 | task_unlock(current); | |
520 | return ret; | |
6b9c7ed8 | 521 | } |
481bed45 | 522 | |
6b9c7ed8 CH |
523 | /** |
524 | * ptrace_get_task_struct -- grab a task struct reference for ptrace | |
525 | * @pid: process id to grab a task_struct reference of | |
526 | * | |
527 | * This function is a helper for ptrace implementations. It checks | |
528 | * permissions and then grabs a task struct for use of the actual | |
529 | * ptrace implementation. | |
530 | * | |
531 | * Returns the task_struct for @pid or an ERR_PTR() on failure. | |
532 | */ | |
533 | struct task_struct *ptrace_get_task_struct(pid_t pid) | |
534 | { | |
535 | struct task_struct *child; | |
481bed45 | 536 | |
481bed45 | 537 | read_lock(&tasklist_lock); |
228ebcbe | 538 | child = find_task_by_vpid(pid); |
481bed45 CH |
539 | if (child) |
540 | get_task_struct(child); | |
f400e198 | 541 | |
481bed45 CH |
542 | read_unlock(&tasklist_lock); |
543 | if (!child) | |
6b9c7ed8 CH |
544 | return ERR_PTR(-ESRCH); |
545 | return child; | |
481bed45 CH |
546 | } |
547 | ||
0ac15559 CH |
548 | #ifndef arch_ptrace_attach |
549 | #define arch_ptrace_attach(child) do { } while (0) | |
550 | #endif | |
551 | ||
481bed45 CH |
552 | asmlinkage long sys_ptrace(long request, long pid, long addr, long data) |
553 | { | |
554 | struct task_struct *child; | |
555 | long ret; | |
556 | ||
557 | /* | |
558 | * This lock_kernel fixes a subtle race with suid exec | |
559 | */ | |
560 | lock_kernel(); | |
6b9c7ed8 CH |
561 | if (request == PTRACE_TRACEME) { |
562 | ret = ptrace_traceme(); | |
6ea6dd93 HS |
563 | if (!ret) |
564 | arch_ptrace_attach(current); | |
481bed45 | 565 | goto out; |
6b9c7ed8 CH |
566 | } |
567 | ||
568 | child = ptrace_get_task_struct(pid); | |
569 | if (IS_ERR(child)) { | |
570 | ret = PTR_ERR(child); | |
571 | goto out; | |
572 | } | |
481bed45 CH |
573 | |
574 | if (request == PTRACE_ATTACH) { | |
575 | ret = ptrace_attach(child); | |
0ac15559 CH |
576 | /* |
577 | * Some architectures need to do book-keeping after | |
578 | * a ptrace attach. | |
579 | */ | |
580 | if (!ret) | |
581 | arch_ptrace_attach(child); | |
005f18df | 582 | goto out_put_task_struct; |
481bed45 CH |
583 | } |
584 | ||
585 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
586 | if (ret < 0) | |
587 | goto out_put_task_struct; | |
588 | ||
589 | ret = arch_ptrace(child, request, addr, data); | |
590 | if (ret < 0) | |
591 | goto out_put_task_struct; | |
592 | ||
593 | out_put_task_struct: | |
594 | put_task_struct(child); | |
595 | out: | |
596 | unlock_kernel(); | |
597 | return ret; | |
598 | } | |
76647323 AD |
599 | |
600 | int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) | |
601 | { | |
602 | unsigned long tmp; | |
603 | int copied; | |
604 | ||
605 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); | |
606 | if (copied != sizeof(tmp)) | |
607 | return -EIO; | |
608 | return put_user(tmp, (unsigned long __user *)data); | |
609 | } | |
f284ce72 AD |
610 | |
611 | int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) | |
612 | { | |
613 | int copied; | |
614 | ||
615 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); | |
616 | return (copied == sizeof(data)) ? 0 : -EIO; | |
617 | } | |
032d82d9 | 618 | |
9d04d928 | 619 | #if defined CONFIG_COMPAT && defined __ARCH_WANT_COMPAT_SYS_PTRACE |
032d82d9 RM |
620 | #include <linux/compat.h> |
621 | ||
622 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, | |
623 | compat_ulong_t addr, compat_ulong_t data) | |
624 | { | |
625 | compat_ulong_t __user *datap = compat_ptr(data); | |
626 | compat_ulong_t word; | |
e16b2781 | 627 | siginfo_t siginfo; |
032d82d9 RM |
628 | int ret; |
629 | ||
630 | switch (request) { | |
631 | case PTRACE_PEEKTEXT: | |
632 | case PTRACE_PEEKDATA: | |
633 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); | |
634 | if (ret != sizeof(word)) | |
635 | ret = -EIO; | |
636 | else | |
637 | ret = put_user(word, datap); | |
638 | break; | |
639 | ||
640 | case PTRACE_POKETEXT: | |
641 | case PTRACE_POKEDATA: | |
642 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); | |
643 | ret = (ret != sizeof(data) ? -EIO : 0); | |
644 | break; | |
645 | ||
646 | case PTRACE_GETEVENTMSG: | |
647 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); | |
648 | break; | |
649 | ||
e16b2781 RM |
650 | case PTRACE_GETSIGINFO: |
651 | ret = ptrace_getsiginfo(child, &siginfo); | |
652 | if (!ret) | |
653 | ret = copy_siginfo_to_user32( | |
654 | (struct compat_siginfo __user *) datap, | |
655 | &siginfo); | |
656 | break; | |
657 | ||
658 | case PTRACE_SETSIGINFO: | |
659 | memset(&siginfo, 0, sizeof siginfo); | |
660 | if (copy_siginfo_from_user32( | |
661 | &siginfo, (struct compat_siginfo __user *) datap)) | |
662 | ret = -EFAULT; | |
663 | else | |
664 | ret = ptrace_setsiginfo(child, &siginfo); | |
665 | break; | |
666 | ||
032d82d9 RM |
667 | default: |
668 | ret = ptrace_request(child, request, addr, data); | |
669 | } | |
670 | ||
671 | return ret; | |
672 | } | |
c269f196 | 673 | |
c269f196 RM |
674 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
675 | compat_long_t addr, compat_long_t data) | |
676 | { | |
677 | struct task_struct *child; | |
678 | long ret; | |
679 | ||
680 | /* | |
681 | * This lock_kernel fixes a subtle race with suid exec | |
682 | */ | |
683 | lock_kernel(); | |
684 | if (request == PTRACE_TRACEME) { | |
685 | ret = ptrace_traceme(); | |
686 | goto out; | |
687 | } | |
688 | ||
689 | child = ptrace_get_task_struct(pid); | |
690 | if (IS_ERR(child)) { | |
691 | ret = PTR_ERR(child); | |
692 | goto out; | |
693 | } | |
694 | ||
695 | if (request == PTRACE_ATTACH) { | |
696 | ret = ptrace_attach(child); | |
697 | /* | |
698 | * Some architectures need to do book-keeping after | |
699 | * a ptrace attach. | |
700 | */ | |
701 | if (!ret) | |
702 | arch_ptrace_attach(child); | |
703 | goto out_put_task_struct; | |
704 | } | |
705 | ||
706 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
707 | if (!ret) | |
708 | ret = compat_arch_ptrace(child, request, addr, data); | |
709 | ||
710 | out_put_task_struct: | |
711 | put_task_struct(child); | |
712 | out: | |
713 | unlock_kernel(); | |
714 | return ret; | |
715 | } | |
9d04d928 | 716 | #endif /* CONFIG_COMPAT && __ARCH_WANT_COMPAT_SYS_PTRACE */ |