1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/kernel/ptrace.c |
4 | * |
5 | * (C) Copyright 1999 Linus Torvalds |
6 | * |
7 | * Common interfaces for "ptrace()" which we do not want |
8 | * to continually duplicate across every architecture. |
9 | */ |
10 | |
11 | #include <linux/capability.h> |
12 | #include <linux/export.h> |
13 | #include <linux/sched.h> |
14 | #include <linux/sched/mm.h> |
15 | #include <linux/sched/coredump.h> |
16 | #include <linux/sched/task.h> |
17 | #include <linux/errno.h> |
18 | #include <linux/mm.h> |
19 | #include <linux/highmem.h> |
20 | #include <linux/pagemap.h> |
21 | #include <linux/ptrace.h> |
22 | #include <linux/security.h> |
23 | #include <linux/signal.h> |
24 | #include <linux/uio.h> |
25 | #include <linux/audit.h> |
26 | #include <linux/pid_namespace.h> |
27 | #include <linux/syscalls.h> |
28 | #include <linux/uaccess.h> |
29 | #include <linux/regset.h> |
30 | #include <linux/hw_breakpoint.h> |
31 | #include <linux/cn_proc.h> |
32 | #include <linux/compat.h> |
33 | #include <linux/sched/signal.h> |
34 | #include <linux/minmax.h> |
35 | #include <linux/syscall_user_dispatch.h> |
36 | |
37 | #include <asm/syscall.h> /* for syscall_get_* */ |
38 | |
39 | /* |
40 | * Access another process' address space via ptrace. |
41 | * Source/target buffer must be kernel space, |
42 | * Do not walk the page table directly, use get_user_pages |
43 | */ |
44 | int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, |
45 | void *buf, int len, unsigned int gup_flags) |
46 | { |
47 | struct mm_struct *mm; |
48 | int ret; |
49 | |
50 | mm = get_task_mm(task: tsk); |
51 | if (!mm) |
52 | return 0; |
53 | |
54 | if (!tsk->ptrace || |
55 | (current != tsk->parent) || |
56 | ((get_dumpable(mm) != SUID_DUMP_USER) && |
57 | !ptracer_capable(tsk, ns: mm->user_ns))) { |
58 | mmput(mm); |
59 | return 0; |
60 | } |
61 | |
62 | ret = access_remote_vm(mm, addr, buf, len, gup_flags); |
63 | mmput(mm); |
64 | |
65 | return ret; |
66 | } |
67 | |
68 | |
69 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, |
70 | const struct cred *ptracer_cred) |
71 | { |
72 | BUG_ON(!list_empty(&child->ptrace_entry)); |
73 | list_add(new: &child->ptrace_entry, head: &new_parent->ptraced); |
74 | child->parent = new_parent; |
75 | child->ptracer_cred = get_cred(cred: ptracer_cred); |
76 | } |
77 | |
78 | /* |
79 | * ptrace a task: make the debugger its new parent and |
80 | * move it to the ptrace list. |
81 | * |
82 | * Must be called with the tasklist lock write-held. |
83 | */ |
84 | static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
85 | { |
86 | __ptrace_link(child, new_parent, current_cred()); |
87 | } |
88 | |
89 | /** |
90 | * __ptrace_unlink - unlink ptracee and restore its execution state |
91 | * @child: ptracee to be unlinked |
92 | * |
93 | * Remove @child from the ptrace list, move it back to the original parent, |
94 | * and restore the execution state so that it conforms to the group stop |
95 | * state. |
96 | * |
97 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer |
98 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between |
99 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. |
100 | * If the ptracer is exiting, the ptracee can be in any state. |
101 | * |
102 | * After detach, the ptracee should be in a state which conforms to the |
103 | * group stop. If the group is stopped or in the process of stopping, the |
104 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken |
105 | * up from TASK_TRACED. |
106 | * |
107 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, |
108 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar |
109 | * to but in the opposite direction of what happens while attaching to a |
110 | * stopped task. However, in this direction, the intermediate RUNNING |
111 | * state is not hidden even from the current ptracer and if it immediately |
112 | * re-attaches and performs a WNOHANG wait(2), it may fail. |
113 | * |
114 | * CONTEXT: |
115 | * write_lock_irq(tasklist_lock) |
116 | */ |
117 | void __ptrace_unlink(struct task_struct *child) |
118 | { |
119 | const struct cred *old_cred; |
120 | BUG_ON(!child->ptrace); |
121 | |
122 | clear_task_syscall_work(child, SYSCALL_TRACE); |
123 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
124 | clear_task_syscall_work(child, SYSCALL_EMU); |
125 | #endif |
126 | |
127 | child->parent = child->real_parent; |
128 | list_del_init(entry: &child->ptrace_entry); |
129 | old_cred = child->ptracer_cred; |
130 | child->ptracer_cred = NULL; |
131 | put_cred(cred: old_cred); |
132 | |
133 | spin_lock(lock: &child->sighand->siglock); |
134 | child->ptrace = 0; |
135 | /* |
136 | * Clear all pending traps and TRAPPING. TRAPPING should be |
137 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. |
138 | */ |
139 | task_clear_jobctl_pending(task: child, JOBCTL_TRAP_MASK); |
140 | task_clear_jobctl_trapping(task: child); |
141 | |
142 | /* |
143 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
144 | * @child isn't dead. |
145 | */ |
146 | if (!(child->flags & PF_EXITING) && |
147 | (child->signal->flags & SIGNAL_STOP_STOPPED || |
148 | child->signal->group_stop_count)) { |
149 | child->jobctl |= JOBCTL_STOP_PENDING; |
150 | |
151 | /* |
152 | * This is only possible if this thread was cloned by the |
153 | * traced task running in the stopped group, set the signal |
154 | * for the future reports. |
155 | * FIXME: we should change ptrace_init_task() to handle this |
156 | * case. |
157 | */ |
158 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) |
159 | child->jobctl |= SIGSTOP; |
160 | } |
161 | |
162 | /* |
163 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick |
164 | * @child in the butt. Note that @resume should be used iff @child |
165 | * is in TASK_TRACED; otherwise, we might unduly disrupt |
166 | * TASK_KILLABLE sleeps. |
167 | */ |
168 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
169 | ptrace_signal_wake_up(t: child, resume: true); |
170 | |
171 | spin_unlock(lock: &child->sighand->siglock); |
172 | } |
173 | |
174 | static bool looks_like_a_spurious_pid(struct task_struct *task) |
175 | { |
176 | if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP)) |
177 | return false; |
178 | |
179 | if (task_pid_vnr(tsk: task) == task->ptrace_message) |
180 | return false; |
181 | /* |
182 | * The tracee changed its pid but the PTRACE_EVENT_EXEC event |
183 | * was not wait()'ed, most probably debugger targets the old |
184 | * leader which was destroyed in de_thread(). |
185 | */ |
186 | return true; |
187 | } |
188 | |
189 | /* |
190 | * Ensure that nothing can wake it up, even SIGKILL |
191 | * |
192 | * A task is switched to this state while a ptrace operation is in progress; |
193 | * such that the ptrace operation is uninterruptible. |
194 | */ |
195 | static bool ptrace_freeze_traced(struct task_struct *task) |
196 | { |
197 | bool ret = false; |
198 | |
199 | /* Lockless, nobody but us can set this flag */ |
200 | if (task->jobctl & JOBCTL_LISTENING) |
201 | return ret; |
202 | |
203 | spin_lock_irq(lock: &task->sighand->siglock); |
204 | if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && |
205 | !__fatal_signal_pending(p: task)) { |
206 | task->jobctl |= JOBCTL_PTRACE_FROZEN; |
207 | ret = true; |
208 | } |
209 | spin_unlock_irq(lock: &task->sighand->siglock); |
210 | |
211 | return ret; |
212 | } |
213 | |
214 | static void ptrace_unfreeze_traced(struct task_struct *task) |
215 | { |
216 | unsigned long flags; |
217 | |
218 | /* |
219 | * The child may be awake and may have cleared |
220 | * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will |
221 | * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew. |
222 | */ |
223 | if (lock_task_sighand(task, flags: &flags)) { |
224 | task->jobctl &= ~JOBCTL_PTRACE_FROZEN; |
225 | if (__fatal_signal_pending(p: task)) { |
226 | task->jobctl &= ~JOBCTL_TRACED; |
227 | wake_up_state(tsk: task, __TASK_TRACED); |
228 | } |
229 | unlock_task_sighand(task, flags: &flags); |
230 | } |
231 | } |
232 | |
233 | /** |
234 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation |
235 | * @child: ptracee to check for |
236 | * @ignore_state: don't check whether @child is currently %TASK_TRACED |
237 | * |
238 | * Check whether @child is being ptraced by %current and ready for further |
239 | * ptrace operations. If @ignore_state is %false, @child also should be in |
240 | * %TASK_TRACED state and on return the child is guaranteed to be traced |
241 | * and not executing. If @ignore_state is %true, @child can be in any |
242 | * state. |
243 | * |
244 | * CONTEXT: |
245 | * Grabs and releases tasklist_lock and @child->sighand->siglock. |
246 | * |
247 | * RETURNS: |
248 | * 0 on success, -ESRCH if %child is not ready. |
249 | */ |
250 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
251 | { |
252 | int ret = -ESRCH; |
253 | |
254 | /* |
255 | * We take the read lock around doing both checks to close a |
256 | * possible race where someone else was tracing our child and |
257 | * detached between these two checks. After this locked check, |
258 | * we are sure that this is our traced child and that can only |
259 | * be changed by us so it's not changing right after this. |
260 | */ |
261 | read_lock(&tasklist_lock); |
262 | if (child->ptrace && child->parent == current) { |
263 | /* |
264 | * child->sighand can't be NULL, release_task() |
265 | * does ptrace_unlink() before __exit_signal(). |
266 | */ |
267 | if (ignore_state || ptrace_freeze_traced(task: child)) |
268 | ret = 0; |
269 | } |
270 | read_unlock(&tasklist_lock); |
271 | |
272 | if (!ret && !ignore_state && |
273 | WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN))) |
274 | ret = -ESRCH; |
275 | |
276 | return ret; |
277 | } |
278 | |
279 | static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode) |
280 | { |
281 | if (mode & PTRACE_MODE_NOAUDIT) |
282 | return ns_capable_noaudit(ns, CAP_SYS_PTRACE); |
283 | return ns_capable(ns, CAP_SYS_PTRACE); |
284 | } |
285 | |
286 | /* Returns 0 on success, -errno on denial. */ |
287 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
288 | { |
289 | const struct cred *cred = current_cred(), *tcred; |
290 | struct mm_struct *mm; |
291 | kuid_t caller_uid; |
292 | kgid_t caller_gid; |
293 | |
294 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { |
295 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n" ); |
296 | return -EPERM; |
297 | } |
298 | |
299 | /* May we inspect the given task? |
300 | * This check is used both for attaching with ptrace |
301 | * and for allowing access to sensitive information in /proc. |
302 | * |
303 | * ptrace_attach denies several cases that /proc allows |
304 | * because setting up the necessary parent/child relationship |
305 | * or halting the specified task is impossible. |
306 | */ |
307 | |
308 | /* Don't let security modules deny introspection */ |
309 | if (same_thread_group(p1: task, current)) |
310 | return 0; |
311 | rcu_read_lock(); |
312 | if (mode & PTRACE_MODE_FSCREDS) { |
313 | caller_uid = cred->fsuid; |
314 | caller_gid = cred->fsgid; |
315 | } else { |
316 | /* |
317 | * Using the euid would make more sense here, but something |
318 | * in userland might rely on the old behavior, and this |
319 | * shouldn't be a security problem since |
320 | * PTRACE_MODE_REALCREDS implies that the caller explicitly |
321 | * used a syscall that requests access to another process |
322 | * (and not a filesystem syscall to procfs). |
323 | */ |
324 | caller_uid = cred->uid; |
325 | caller_gid = cred->gid; |
326 | } |
327 | tcred = __task_cred(task); |
328 | if (uid_eq(left: caller_uid, right: tcred->euid) && |
329 | uid_eq(left: caller_uid, right: tcred->suid) && |
330 | uid_eq(left: caller_uid, right: tcred->uid) && |
331 | gid_eq(left: caller_gid, right: tcred->egid) && |
332 | gid_eq(left: caller_gid, right: tcred->sgid) && |
333 | gid_eq(left: caller_gid, right: tcred->gid)) |
334 | goto ok; |
335 | if (ptrace_has_cap(ns: tcred->user_ns, mode)) |
336 | goto ok; |
337 | rcu_read_unlock(); |
338 | return -EPERM; |
339 | ok: |
340 | rcu_read_unlock(); |
341 | /* |
342 | * If a task drops privileges and becomes nondumpable (through a syscall |
343 | * like setresuid()) while we are trying to access it, we must ensure |
344 | * that the dumpability is read after the credentials; otherwise, |
345 | * we may be able to attach to a task that we shouldn't be able to |
346 | * attach to (as if the task had dropped privileges without becoming |
347 | * nondumpable). |
348 | * Pairs with a write barrier in commit_creds(). |
349 | */ |
350 | smp_rmb(); |
351 | mm = task->mm; |
352 | if (mm && |
353 | ((get_dumpable(mm) != SUID_DUMP_USER) && |
354 | !ptrace_has_cap(ns: mm->user_ns, mode))) |
355 | return -EPERM; |
356 | |
357 | return security_ptrace_access_check(child: task, mode); |
358 | } |
359 | |
360 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
361 | { |
362 | int err; |
363 | task_lock(p: task); |
364 | err = __ptrace_may_access(task, mode); |
365 | task_unlock(p: task); |
366 | return !err; |
367 | } |
368 | |
369 | static int check_ptrace_options(unsigned long data) |
370 | { |
371 | if (data & ~(unsigned long)PTRACE_O_MASK) |
372 | return -EINVAL; |
373 | |
374 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { |
375 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || |
376 | !IS_ENABLED(CONFIG_SECCOMP)) |
377 | return -EINVAL; |
378 | |
379 | if (!capable(CAP_SYS_ADMIN)) |
380 | return -EPERM; |
381 | |
382 | if (seccomp_mode(s: ¤t->seccomp) != SECCOMP_MODE_DISABLED || |
383 | current->ptrace & PT_SUSPEND_SECCOMP) |
384 | return -EPERM; |
385 | } |
386 | return 0; |
387 | } |
388 | |
389 | static int ptrace_attach(struct task_struct *task, long request, |
390 | unsigned long addr, |
391 | unsigned long flags) |
392 | { |
393 | bool seize = (request == PTRACE_SEIZE); |
394 | int retval; |
395 | |
396 | retval = -EIO; |
397 | if (seize) { |
398 | if (addr != 0) |
399 | goto out; |
400 | /* |
401 | * This duplicates the check in check_ptrace_options() because |
402 | * ptrace_attach() and ptrace_setoptions() have historically |
403 | * used different error codes for unknown ptrace options. |
404 | */ |
405 | if (flags & ~(unsigned long)PTRACE_O_MASK) |
406 | goto out; |
407 | retval = check_ptrace_options(data: flags); |
408 | if (retval) |
409 | return retval; |
410 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); |
411 | } else { |
412 | flags = PT_PTRACED; |
413 | } |
414 | |
415 | audit_ptrace(t: task); |
416 | |
417 | retval = -EPERM; |
418 | if (unlikely(task->flags & PF_KTHREAD)) |
419 | goto out; |
420 | if (same_thread_group(p1: task, current)) |
421 | goto out; |
422 | |
423 | /* |
424 | * Protect exec's credential calculations against our interference; |
425 | * SUID, SGID and LSM creds get determined differently |
426 | * under ptrace. |
427 | */ |
428 | retval = -ERESTARTNOINTR; |
429 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
430 | goto out; |
431 | |
432 | task_lock(p: task); |
433 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); |
434 | task_unlock(p: task); |
435 | if (retval) |
436 | goto unlock_creds; |
437 | |
438 | write_lock_irq(&tasklist_lock); |
439 | retval = -EPERM; |
440 | if (unlikely(task->exit_state)) |
441 | goto unlock_tasklist; |
442 | if (task->ptrace) |
443 | goto unlock_tasklist; |
444 | |
445 | task->ptrace = flags; |
446 | |
447 | ptrace_link(child: task, current); |
448 | |
449 | /* SEIZE doesn't trap tracee on attach */ |
450 | if (!seize) |
451 | send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); |
452 | |
453 | spin_lock(lock: &task->sighand->siglock); |
454 | |
455 | /* |
456 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and |
457 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
458 | * will be cleared if the child completes the transition or any |
459 | * event which clears the group stop states happens. We'll wait |
460 | * for the transition to complete before returning from this |
461 | * function. |
462 | * |
463 | * This hides STOPPED -> RUNNING -> TRACED transition from the |
464 | * attaching thread but a different thread in the same group can |
465 | * still observe the transient RUNNING state. IOW, if another |
466 | * thread's WNOHANG wait(2) on the stopped tracee races against |
467 | * ATTACH, the wait(2) may fail due to the transient RUNNING. |
468 | * |
469 | * The following task_is_stopped() test is safe as both transitions |
470 | * in and out of STOPPED are protected by siglock. |
471 | */ |
472 | if (task_is_stopped(task) && |
473 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) { |
474 | task->jobctl &= ~JOBCTL_STOPPED; |
475 | signal_wake_up_state(t: task, __TASK_STOPPED); |
476 | } |
477 | |
478 | spin_unlock(lock: &task->sighand->siglock); |
479 | |
480 | retval = 0; |
481 | unlock_tasklist: |
482 | write_unlock_irq(&tasklist_lock); |
483 | unlock_creds: |
484 | mutex_unlock(lock: &task->signal->cred_guard_mutex); |
485 | out: |
486 | if (!retval) { |
487 | /* |
488 | * We do not bother to change retval or clear JOBCTL_TRAPPING |
489 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will |
490 | * not return to user-mode, it will exit and clear this bit in |
491 | * __ptrace_unlink() if it wasn't already cleared by the tracee; |
492 | * and until then nobody can ptrace this task. |
493 | */ |
494 | wait_on_bit(word: &task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); |
495 | proc_ptrace_connector(task, PTRACE_ATTACH); |
496 | } |
497 | |
498 | return retval; |
499 | } |
500 | |
501 | /** |
502 | * ptrace_traceme -- helper for PTRACE_TRACEME |
503 | * |
504 | * Performs checks and sets PT_PTRACED. |
505 | * Should be used by all ptrace implementations for PTRACE_TRACEME. |
506 | */ |
507 | static int ptrace_traceme(void) |
508 | { |
509 | int ret = -EPERM; |
510 | |
511 | write_lock_irq(&tasklist_lock); |
512 | /* Are we already being traced? */ |
513 | if (!current->ptrace) { |
514 | ret = security_ptrace_traceme(current->parent); |
515 | /* |
516 | * Check PF_EXITING to ensure ->real_parent has not passed |
517 | * exit_ptrace(). Otherwise we don't report the error but |
518 | * pretend ->real_parent untraces us right after return. |
519 | */ |
520 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { |
521 | current->ptrace = PT_PTRACED; |
522 | ptrace_link(current, current->real_parent); |
523 | } |
524 | } |
525 | write_unlock_irq(&tasklist_lock); |
526 | |
527 | return ret; |
528 | } |
529 | |
530 | /* |
531 | * Called with irqs disabled, returns true if childs should reap themselves. |
532 | */ |
533 | static int ignoring_children(struct sighand_struct *sigh) |
534 | { |
535 | int ret; |
536 | spin_lock(lock: &sigh->siglock); |
537 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || |
538 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); |
539 | spin_unlock(lock: &sigh->siglock); |
540 | return ret; |
541 | } |
542 | |
543 | /* |
544 | * Called with tasklist_lock held for writing. |
545 | * Unlink a traced task, and clean it up if it was a traced zombie. |
546 | * Return true if it needs to be reaped with release_task(). |
547 | * (We can't call release_task() here because we already hold tasklist_lock.) |
548 | * |
549 | * If it's a zombie, our attachedness prevented normal parent notification |
550 | * or self-reaping. Do notification now if it would have happened earlier. |
551 | * If it should reap itself, return true. |
552 | * |
553 | * If it's our own child, there is no notification to do. But if our normal |
554 | * children self-reap, then this child was prevented by ptrace and we must |
555 | * reap it now, in that case we must also wake up sub-threads sleeping in |
556 | * do_wait(). |
557 | */ |
558 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) |
559 | { |
560 | bool dead; |
561 | |
562 | __ptrace_unlink(child: p); |
563 | |
564 | if (p->exit_state != EXIT_ZOMBIE) |
565 | return false; |
566 | |
567 | dead = !thread_group_leader(p); |
568 | |
569 | if (!dead && thread_group_empty(p)) { |
570 | if (!same_thread_group(p1: p->real_parent, p2: tracer)) |
571 | dead = do_notify_parent(p, p->exit_signal); |
572 | else if (ignoring_children(sigh: tracer->sighand)) { |
573 | __wake_up_parent(p, parent: tracer); |
574 | dead = true; |
575 | } |
576 | } |
577 | /* Mark it as in the process of being reaped. */ |
578 | if (dead) |
579 | p->exit_state = EXIT_DEAD; |
580 | return dead; |
581 | } |
582 | |
583 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
584 | { |
585 | if (!valid_signal(sig: data)) |
586 | return -EIO; |
587 | |
588 | /* Architecture-specific hardware disable .. */ |
589 | ptrace_disable(child); |
590 | |
591 | write_lock_irq(&tasklist_lock); |
592 | /* |
593 | * We rely on ptrace_freeze_traced(). It can't be killed and |
594 | * untraced by another thread, it can't be a zombie. |
595 | */ |
596 | WARN_ON(!child->ptrace || child->exit_state); |
597 | /* |
598 | * tasklist_lock avoids the race with wait_task_stopped(), see |
599 | * the comment in ptrace_resume(). |
600 | */ |
601 | child->exit_code = data; |
602 | __ptrace_detach(current, p: child); |
603 | write_unlock_irq(&tasklist_lock); |
604 | |
605 | proc_ptrace_connector(task: child, PTRACE_DETACH); |
606 | |
607 | return 0; |
608 | } |
609 | |
610 | /* |
611 | * Detach all tasks we were using ptrace on. Called with tasklist held |
612 | * for writing. |
613 | */ |
614 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead) |
615 | { |
616 | struct task_struct *p, *n; |
617 | |
618 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
619 | if (unlikely(p->ptrace & PT_EXITKILL)) |
620 | send_sig_info(SIGKILL, SEND_SIG_PRIV, p); |
621 | |
622 | if (__ptrace_detach(tracer, p)) |
623 | list_add(new: &p->ptrace_entry, head: dead); |
624 | } |
625 | } |
626 | |
627 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
628 | { |
629 | int copied = 0; |
630 | |
631 | while (len > 0) { |
632 | char buf[128]; |
633 | int this_len, retval; |
634 | |
635 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
636 | retval = ptrace_access_vm(tsk, addr: src, buf, len: this_len, gup_flags: FOLL_FORCE); |
637 | |
638 | if (!retval) { |
639 | if (copied) |
640 | break; |
641 | return -EIO; |
642 | } |
643 | if (copy_to_user(to: dst, from: buf, n: retval)) |
644 | return -EFAULT; |
645 | copied += retval; |
646 | src += retval; |
647 | dst += retval; |
648 | len -= retval; |
649 | } |
650 | return copied; |
651 | } |
652 | |
653 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) |
654 | { |
655 | int copied = 0; |
656 | |
657 | while (len > 0) { |
658 | char buf[128]; |
659 | int this_len, retval; |
660 | |
661 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
662 | if (copy_from_user(to: buf, from: src, n: this_len)) |
663 | return -EFAULT; |
664 | retval = ptrace_access_vm(tsk, addr: dst, buf, len: this_len, |
665 | gup_flags: FOLL_FORCE | FOLL_WRITE); |
666 | if (!retval) { |
667 | if (copied) |
668 | break; |
669 | return -EIO; |
670 | } |
671 | copied += retval; |
672 | src += retval; |
673 | dst += retval; |
674 | len -= retval; |
675 | } |
676 | return copied; |
677 | } |
678 | |
679 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
680 | { |
681 | unsigned flags; |
682 | int ret; |
683 | |
684 | ret = check_ptrace_options(data); |
685 | if (ret) |
686 | return ret; |
687 | |
688 | /* Avoid intermediate state when all opts are cleared */ |
689 | flags = child->ptrace; |
690 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); |
691 | flags |= (data << PT_OPT_FLAG_SHIFT); |
692 | child->ptrace = flags; |
693 | |
694 | return 0; |
695 | } |
696 | |
697 | static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) |
698 | { |
699 | unsigned long flags; |
700 | int error = -ESRCH; |
701 | |
702 | if (lock_task_sighand(task: child, flags: &flags)) { |
703 | error = -EINVAL; |
704 | if (likely(child->last_siginfo != NULL)) { |
705 | copy_siginfo(to: info, from: child->last_siginfo); |
706 | error = 0; |
707 | } |
708 | unlock_task_sighand(task: child, flags: &flags); |
709 | } |
710 | return error; |
711 | } |
712 | |
713 | static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) |
714 | { |
715 | unsigned long flags; |
716 | int error = -ESRCH; |
717 | |
718 | if (lock_task_sighand(task: child, flags: &flags)) { |
719 | error = -EINVAL; |
720 | if (likely(child->last_siginfo != NULL)) { |
721 | copy_siginfo(to: child->last_siginfo, from: info); |
722 | error = 0; |
723 | } |
724 | unlock_task_sighand(task: child, flags: &flags); |
725 | } |
726 | return error; |
727 | } |
728 | |
729 | static int ptrace_peek_siginfo(struct task_struct *child, |
730 | unsigned long addr, |
731 | unsigned long data) |
732 | { |
733 | struct ptrace_peeksiginfo_args arg; |
734 | struct sigpending *pending; |
735 | struct sigqueue *q; |
736 | int ret, i; |
737 | |
738 | ret = copy_from_user(to: &arg, from: (void __user *) addr, |
739 | n: sizeof(struct ptrace_peeksiginfo_args)); |
740 | if (ret) |
741 | return -EFAULT; |
742 | |
743 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) |
744 | return -EINVAL; /* unknown flags */ |
745 | |
746 | if (arg.nr < 0) |
747 | return -EINVAL; |
748 | |
749 | /* Ensure arg.off fits in an unsigned long */ |
750 | if (arg.off > ULONG_MAX) |
751 | return 0; |
752 | |
753 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) |
754 | pending = &child->signal->shared_pending; |
755 | else |
756 | pending = &child->pending; |
757 | |
758 | for (i = 0; i < arg.nr; ) { |
759 | kernel_siginfo_t info; |
760 | unsigned long off = arg.off + i; |
761 | bool found = false; |
762 | |
763 | spin_lock_irq(lock: &child->sighand->siglock); |
764 | list_for_each_entry(q, &pending->list, list) { |
765 | if (!off--) { |
766 | found = true; |
767 | copy_siginfo(to: &info, from: &q->info); |
768 | break; |
769 | } |
770 | } |
771 | spin_unlock_irq(lock: &child->sighand->siglock); |
772 | |
773 | if (!found) /* beyond the end of the list */ |
774 | break; |
775 | |
776 | #ifdef CONFIG_COMPAT |
777 | if (unlikely(in_compat_syscall())) { |
778 | compat_siginfo_t __user *uinfo = compat_ptr(uptr: data); |
779 | |
780 | if (copy_siginfo_to_user32(to: uinfo, from: &info)) { |
781 | ret = -EFAULT; |
782 | break; |
783 | } |
784 | |
785 | } else |
786 | #endif |
787 | { |
788 | siginfo_t __user *uinfo = (siginfo_t __user *) data; |
789 | |
790 | if (copy_siginfo_to_user(to: uinfo, from: &info)) { |
791 | ret = -EFAULT; |
792 | break; |
793 | } |
794 | } |
795 | |
796 | data += sizeof(siginfo_t); |
797 | i++; |
798 | |
799 | if (signal_pending(current)) |
800 | break; |
801 | |
802 | cond_resched(); |
803 | } |
804 | |
805 | if (i > 0) |
806 | return i; |
807 | |
808 | return ret; |
809 | } |
810 | |
811 | #ifdef CONFIG_RSEQ |
812 | static long ptrace_get_rseq_configuration(struct task_struct *task, |
813 | unsigned long size, void __user *data) |
814 | { |
815 | struct ptrace_rseq_configuration conf = { |
816 | .rseq_abi_pointer = (u64)(uintptr_t)task->rseq, |
817 | .rseq_abi_size = task->rseq_len, |
818 | .signature = task->rseq_sig, |
819 | .flags = 0, |
820 | }; |
821 | |
822 | size = min_t(unsigned long, size, sizeof(conf)); |
823 | if (copy_to_user(to: data, from: &conf, n: size)) |
824 | return -EFAULT; |
825 | return sizeof(conf); |
826 | } |
827 | #endif |
828 | |
829 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) |
830 | |
831 | #ifdef PTRACE_SINGLEBLOCK |
832 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) |
833 | #else |
834 | #define is_singleblock(request) 0 |
835 | #endif |
836 | |
837 | #ifdef PTRACE_SYSEMU |
838 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) |
839 | #else |
840 | #define is_sysemu_singlestep(request) 0 |
841 | #endif |
842 | |
843 | static int ptrace_resume(struct task_struct *child, long request, |
844 | unsigned long data) |
845 | { |
846 | if (!valid_signal(sig: data)) |
847 | return -EIO; |
848 | |
849 | if (request == PTRACE_SYSCALL) |
850 | set_task_syscall_work(child, SYSCALL_TRACE); |
851 | else |
852 | clear_task_syscall_work(child, SYSCALL_TRACE); |
853 | |
854 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) |
855 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
856 | set_task_syscall_work(child, SYSCALL_EMU); |
857 | else |
858 | clear_task_syscall_work(child, SYSCALL_EMU); |
859 | #endif |
860 | |
861 | if (is_singleblock(request)) { |
862 | if (unlikely(!arch_has_block_step())) |
863 | return -EIO; |
864 | user_enable_block_step(child); |
865 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { |
866 | if (unlikely(!arch_has_single_step())) |
867 | return -EIO; |
868 | user_enable_single_step(child); |
869 | } else { |
870 | user_disable_single_step(child); |
871 | } |
872 | |
873 | /* |
874 | * Change ->exit_code and ->state under siglock to avoid the race |
875 | * with wait_task_stopped() in between; a non-zero ->exit_code will |
876 | * wrongly look like another report from tracee. |
877 | * |
878 | * Note that we need siglock even if ->exit_code == data and/or this |
879 | * status was not reported yet, the new status must not be cleared by |
880 | * wait_task_stopped() after resume. |
881 | */ |
882 | spin_lock_irq(lock: &child->sighand->siglock); |
883 | child->exit_code = data; |
884 | child->jobctl &= ~JOBCTL_TRACED; |
885 | wake_up_state(tsk: child, __TASK_TRACED); |
886 | spin_unlock_irq(lock: &child->sighand->siglock); |
887 | |
888 | return 0; |
889 | } |
890 | |
891 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
892 | |
893 | static const struct user_regset * |
894 | find_regset(const struct user_regset_view *view, unsigned int type) |
895 | { |
896 | const struct user_regset *regset; |
897 | int n; |
898 | |
899 | for (n = 0; n < view->n; ++n) { |
900 | regset = view->regsets + n; |
901 | if (regset->core_note_type == type) |
902 | return regset; |
903 | } |
904 | |
905 | return NULL; |
906 | } |
907 | |
908 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, |
909 | struct iovec *kiov) |
910 | { |
911 | const struct user_regset_view *view = task_user_regset_view(tsk: task); |
912 | const struct user_regset *regset = find_regset(view, type); |
913 | int regset_no; |
914 | |
915 | if (!regset || (kiov->iov_len % regset->size) != 0) |
916 | return -EINVAL; |
917 | |
918 | regset_no = regset - view->regsets; |
919 | kiov->iov_len = min(kiov->iov_len, |
920 | (__kernel_size_t) (regset->n * regset->size)); |
921 | |
922 | if (req == PTRACE_GETREGSET) |
923 | return copy_regset_to_user(target: task, view, setno: regset_no, offset: 0, |
924 | size: kiov->iov_len, data: kiov->iov_base); |
925 | else |
926 | return copy_regset_from_user(target: task, view, setno: regset_no, offset: 0, |
927 | size: kiov->iov_len, data: kiov->iov_base); |
928 | } |
929 | |
930 | /* |
931 | * This is declared in linux/regset.h and defined in machine-dependent |
932 | * code. We put the export here, near the primary machine-neutral use, |
933 | * to ensure no machine forgets it. |
934 | */ |
935 | EXPORT_SYMBOL_GPL(task_user_regset_view); |
936 | |
937 | static unsigned long |
938 | ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, |
939 | struct ptrace_syscall_info *info) |
940 | { |
941 | unsigned long args[ARRAY_SIZE(info->entry.args)]; |
942 | int i; |
943 | |
944 | info->op = PTRACE_SYSCALL_INFO_ENTRY; |
945 | info->entry.nr = syscall_get_nr(task: child, regs); |
946 | syscall_get_arguments(task: child, regs, args); |
947 | for (i = 0; i < ARRAY_SIZE(args); i++) |
948 | info->entry.args[i] = args[i]; |
949 | |
950 | /* args is the last field in struct ptrace_syscall_info.entry */ |
951 | return offsetofend(struct ptrace_syscall_info, entry.args); |
952 | } |
953 | |
954 | static unsigned long |
955 | ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, |
956 | struct ptrace_syscall_info *info) |
957 | { |
958 | /* |
959 | * As struct ptrace_syscall_info.entry is currently a subset |
960 | * of struct ptrace_syscall_info.seccomp, it makes sense to |
961 | * initialize that subset using ptrace_get_syscall_info_entry(). |
962 | * This can be reconsidered in the future if these structures |
963 | * diverge significantly enough. |
964 | */ |
965 | ptrace_get_syscall_info_entry(child, regs, info); |
966 | info->op = PTRACE_SYSCALL_INFO_SECCOMP; |
967 | info->seccomp.ret_data = child->ptrace_message; |
968 | |
969 | /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ |
970 | return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); |
971 | } |
972 | |
973 | static unsigned long |
974 | ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, |
975 | struct ptrace_syscall_info *info) |
976 | { |
977 | info->op = PTRACE_SYSCALL_INFO_EXIT; |
978 | info->exit.rval = syscall_get_error(task: child, regs); |
979 | info->exit.is_error = !!info->exit.rval; |
980 | if (!info->exit.is_error) |
981 | info->exit.rval = syscall_get_return_value(task: child, regs); |
982 | |
983 | /* is_error is the last field in struct ptrace_syscall_info.exit */ |
984 | return offsetofend(struct ptrace_syscall_info, exit.is_error); |
985 | } |
986 | |
987 | static int |
988 | ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, |
989 | void __user *datavp) |
990 | { |
991 | struct pt_regs *regs = task_pt_regs(child); |
992 | struct ptrace_syscall_info info = { |
993 | .op = PTRACE_SYSCALL_INFO_NONE, |
994 | .arch = syscall_get_arch(task: child), |
995 | .instruction_pointer = instruction_pointer(regs), |
996 | .stack_pointer = user_stack_pointer(regs), |
997 | }; |
998 | unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); |
999 | unsigned long write_size; |
1000 | |
1001 | /* |
1002 | * This does not need lock_task_sighand() to access |
1003 | * child->last_siginfo because ptrace_freeze_traced() |
1004 | * called earlier by ptrace_check_attach() ensures that |
1005 | * the tracee cannot go away and clear its last_siginfo. |
1006 | */ |
1007 | switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { |
1008 | case SIGTRAP | 0x80: |
1009 | switch (child->ptrace_message) { |
1010 | case PTRACE_EVENTMSG_SYSCALL_ENTRY: |
1011 | actual_size = ptrace_get_syscall_info_entry(child, regs, |
1012 | info: &info); |
1013 | break; |
1014 | case PTRACE_EVENTMSG_SYSCALL_EXIT: |
1015 | actual_size = ptrace_get_syscall_info_exit(child, regs, |
1016 | info: &info); |
1017 | break; |
1018 | } |
1019 | break; |
1020 | case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): |
1021 | actual_size = ptrace_get_syscall_info_seccomp(child, regs, |
1022 | info: &info); |
1023 | break; |
1024 | } |
1025 | |
1026 | write_size = min(actual_size, user_size); |
1027 | return copy_to_user(to: datavp, from: &info, n: write_size) ? -EFAULT : actual_size; |
1028 | } |
1029 | #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ |
1030 | |
1031 | int ptrace_request(struct task_struct *child, long request, |
1032 | unsigned long addr, unsigned long data) |
1033 | { |
1034 | bool seized = child->ptrace & PT_SEIZED; |
1035 | int ret = -EIO; |
1036 | kernel_siginfo_t siginfo, *si; |
1037 | void __user *datavp = (void __user *) data; |
1038 | unsigned long __user *datalp = datavp; |
1039 | unsigned long flags; |
1040 | |
1041 | switch (request) { |
1042 | case PTRACE_PEEKTEXT: |
1043 | case PTRACE_PEEKDATA: |
1044 | return generic_ptrace_peekdata(tsk: child, addr, data); |
1045 | case PTRACE_POKETEXT: |
1046 | case PTRACE_POKEDATA: |
1047 | return generic_ptrace_pokedata(tsk: child, addr, data); |
1048 | |
1049 | #ifdef PTRACE_OLDSETOPTIONS |
1050 | case PTRACE_OLDSETOPTIONS: |
1051 | #endif |
1052 | case PTRACE_SETOPTIONS: |
1053 | ret = ptrace_setoptions(child, data); |
1054 | break; |
1055 | case PTRACE_GETEVENTMSG: |
1056 | ret = put_user(child->ptrace_message, datalp); |
1057 | break; |
1058 | |
1059 | case PTRACE_PEEKSIGINFO: |
1060 | ret = ptrace_peek_siginfo(child, addr, data); |
1061 | break; |
1062 | |
1063 | case PTRACE_GETSIGINFO: |
1064 | ret = ptrace_getsiginfo(child, info: &siginfo); |
1065 | if (!ret) |
1066 | ret = copy_siginfo_to_user(to: datavp, from: &siginfo); |
1067 | break; |
1068 | |
1069 | case PTRACE_SETSIGINFO: |
1070 | ret = copy_siginfo_from_user(to: &siginfo, from: datavp); |
1071 | if (!ret) |
1072 | ret = ptrace_setsiginfo(child, info: &siginfo); |
1073 | break; |
1074 | |
1075 | case PTRACE_GETSIGMASK: { |
1076 | sigset_t *mask; |
1077 | |
1078 | if (addr != sizeof(sigset_t)) { |
1079 | ret = -EINVAL; |
1080 | break; |
1081 | } |
1082 | |
1083 | if (test_tsk_restore_sigmask(task: child)) |
1084 | mask = &child->saved_sigmask; |
1085 | else |
1086 | mask = &child->blocked; |
1087 | |
1088 | if (copy_to_user(to: datavp, from: mask, n: sizeof(sigset_t))) |
1089 | ret = -EFAULT; |
1090 | else |
1091 | ret = 0; |
1092 | |
1093 | break; |
1094 | } |
1095 | |
1096 | case PTRACE_SETSIGMASK: { |
1097 | sigset_t new_set; |
1098 | |
1099 | if (addr != sizeof(sigset_t)) { |
1100 | ret = -EINVAL; |
1101 | break; |
1102 | } |
1103 | |
1104 | if (copy_from_user(to: &new_set, from: datavp, n: sizeof(sigset_t))) { |
1105 | ret = -EFAULT; |
1106 | break; |
1107 | } |
1108 | |
1109 | sigdelsetmask(set: &new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
1110 | |
1111 | /* |
1112 | * Every thread does recalc_sigpending() after resume, so |
1113 | * retarget_shared_pending() and recalc_sigpending() are not |
1114 | * called here. |
1115 | */ |
1116 | spin_lock_irq(lock: &child->sighand->siglock); |
1117 | child->blocked = new_set; |
1118 | spin_unlock_irq(lock: &child->sighand->siglock); |
1119 | |
1120 | clear_tsk_restore_sigmask(task: child); |
1121 | |
1122 | ret = 0; |
1123 | break; |
1124 | } |
1125 | |
1126 | case PTRACE_INTERRUPT: |
1127 | /* |
1128 | * Stop tracee without any side-effect on signal or job |
1129 | * control. At least one trap is guaranteed to happen |
1130 | * after this request. If @child is already trapped, the |
1131 | * current trap is not disturbed and another trap will |
1132 | * happen after the current trap is ended with PTRACE_CONT. |
1133 | * |
1134 | * The actual trap might not be PTRACE_EVENT_STOP trap but |
1135 | * the pending condition is cleared regardless. |
1136 | */ |
1137 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) |
1138 | break; |
1139 | |
1140 | /* |
1141 | * INTERRUPT doesn't disturb existing trap sans one |
1142 | * exception. If ptracer issued LISTEN for the current |
1143 | * STOP, this INTERRUPT should clear LISTEN and re-trap |
1144 | * tracee into STOP. |
1145 | */ |
1146 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) |
1147 | ptrace_signal_wake_up(t: child, resume: child->jobctl & JOBCTL_LISTENING); |
1148 | |
1149 | unlock_task_sighand(task: child, flags: &flags); |
1150 | ret = 0; |
1151 | break; |
1152 | |
1153 | case PTRACE_LISTEN: |
1154 | /* |
1155 | * Listen for events. Tracee must be in STOP. It's not |
1156 | * resumed per-se but is not considered to be in TRACED by |
1157 | * wait(2) or ptrace(2). If an async event (e.g. group |
1158 | * stop state change) happens, tracee will enter STOP trap |
1159 | * again. Alternatively, ptracer can issue INTERRUPT to |
1160 | * finish listening and re-trap tracee into STOP. |
1161 | */ |
1162 | if (unlikely(!seized || !lock_task_sighand(child, &flags))) |
1163 | break; |
1164 | |
1165 | si = child->last_siginfo; |
1166 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { |
1167 | child->jobctl |= JOBCTL_LISTENING; |
1168 | /* |
1169 | * If NOTIFY is set, it means event happened between |
1170 | * start of this trap and now. Trigger re-trap. |
1171 | */ |
1172 | if (child->jobctl & JOBCTL_TRAP_NOTIFY) |
1173 | ptrace_signal_wake_up(t: child, resume: true); |
1174 | ret = 0; |
1175 | } |
1176 | unlock_task_sighand(task: child, flags: &flags); |
1177 | break; |
1178 | |
1179 | case PTRACE_DETACH: /* detach a process that was attached. */ |
1180 | ret = ptrace_detach(child, data); |
1181 | break; |
1182 | |
1183 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
1184 | case PTRACE_GETFDPIC: { |
1185 | struct mm_struct *mm = get_task_mm(child); |
1186 | unsigned long tmp = 0; |
1187 | |
1188 | ret = -ESRCH; |
1189 | if (!mm) |
1190 | break; |
1191 | |
1192 | switch (addr) { |
1193 | case PTRACE_GETFDPIC_EXEC: |
1194 | tmp = mm->context.exec_fdpic_loadmap; |
1195 | break; |
1196 | case PTRACE_GETFDPIC_INTERP: |
1197 | tmp = mm->context.interp_fdpic_loadmap; |
1198 | break; |
1199 | default: |
1200 | break; |
1201 | } |
1202 | mmput(mm); |
1203 | |
1204 | ret = put_user(tmp, datalp); |
1205 | break; |
1206 | } |
1207 | #endif |
1208 | |
1209 | case PTRACE_SINGLESTEP: |
1210 | #ifdef PTRACE_SINGLEBLOCK |
1211 | case PTRACE_SINGLEBLOCK: |
1212 | #endif |
1213 | #ifdef PTRACE_SYSEMU |
1214 | case PTRACE_SYSEMU: |
1215 | case PTRACE_SYSEMU_SINGLESTEP: |
1216 | #endif |
1217 | case PTRACE_SYSCALL: |
1218 | case PTRACE_CONT: |
1219 | return ptrace_resume(child, request, data); |
1220 | |
1221 | case PTRACE_KILL: |
1222 | send_sig_info(SIGKILL, SEND_SIG_NOINFO, child); |
1223 | return 0; |
1224 | |
1225 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1226 | case PTRACE_GETREGSET: |
1227 | case PTRACE_SETREGSET: { |
1228 | struct iovec kiov; |
1229 | struct iovec __user *uiov = datavp; |
1230 | |
1231 | if (!access_ok(uiov, sizeof(*uiov))) |
1232 | return -EFAULT; |
1233 | |
1234 | if (__get_user(kiov.iov_base, &uiov->iov_base) || |
1235 | __get_user(kiov.iov_len, &uiov->iov_len)) |
1236 | return -EFAULT; |
1237 | |
1238 | ret = ptrace_regset(task: child, req: request, type: addr, kiov: &kiov); |
1239 | if (!ret) |
1240 | ret = __put_user(kiov.iov_len, &uiov->iov_len); |
1241 | break; |
1242 | } |
1243 | |
1244 | case PTRACE_GET_SYSCALL_INFO: |
1245 | ret = ptrace_get_syscall_info(child, user_size: addr, datavp); |
1246 | break; |
1247 | #endif |
1248 | |
1249 | case PTRACE_SECCOMP_GET_FILTER: |
1250 | ret = seccomp_get_filter(task: child, filter_off: addr, data: datavp); |
1251 | break; |
1252 | |
1253 | case PTRACE_SECCOMP_GET_METADATA: |
1254 | ret = seccomp_get_metadata(task: child, filter_off: addr, data: datavp); |
1255 | break; |
1256 | |
1257 | #ifdef CONFIG_RSEQ |
1258 | case PTRACE_GET_RSEQ_CONFIGURATION: |
1259 | ret = ptrace_get_rseq_configuration(task: child, size: addr, data: datavp); |
1260 | break; |
1261 | #endif |
1262 | |
1263 | case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG: |
1264 | ret = syscall_user_dispatch_set_config(task: child, size: addr, data: datavp); |
1265 | break; |
1266 | |
1267 | case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG: |
1268 | ret = syscall_user_dispatch_get_config(task: child, size: addr, data: datavp); |
1269 | break; |
1270 | |
1271 | default: |
1272 | break; |
1273 | } |
1274 | |
1275 | return ret; |
1276 | } |
1277 | |
1278 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
1279 | unsigned long, data) |
1280 | { |
1281 | struct task_struct *child; |
1282 | long ret; |
1283 | |
1284 | if (request == PTRACE_TRACEME) { |
1285 | ret = ptrace_traceme(); |
1286 | goto out; |
1287 | } |
1288 | |
1289 | child = find_get_task_by_vpid(nr: pid); |
1290 | if (!child) { |
1291 | ret = -ESRCH; |
1292 | goto out; |
1293 | } |
1294 | |
1295 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
1296 | ret = ptrace_attach(task: child, request, addr, flags: data); |
1297 | goto out_put_task_struct; |
1298 | } |
1299 | |
1300 | ret = ptrace_check_attach(child, ignore_state: request == PTRACE_KILL || |
1301 | request == PTRACE_INTERRUPT); |
1302 | if (ret < 0) |
1303 | goto out_put_task_struct; |
1304 | |
1305 | ret = arch_ptrace(child, request, addr, data); |
1306 | if (ret || request != PTRACE_DETACH) |
1307 | ptrace_unfreeze_traced(task: child); |
1308 | |
1309 | out_put_task_struct: |
1310 | put_task_struct(t: child); |
1311 | out: |
1312 | return ret; |
1313 | } |
1314 | |
1315 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
1316 | unsigned long data) |
1317 | { |
1318 | unsigned long tmp; |
1319 | int copied; |
1320 | |
1321 | copied = ptrace_access_vm(tsk, addr, buf: &tmp, len: sizeof(tmp), gup_flags: FOLL_FORCE); |
1322 | if (copied != sizeof(tmp)) |
1323 | return -EIO; |
1324 | return put_user(tmp, (unsigned long __user *)data); |
1325 | } |
1326 | |
1327 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
1328 | unsigned long data) |
1329 | { |
1330 | int copied; |
1331 | |
1332 | copied = ptrace_access_vm(tsk, addr, buf: &data, len: sizeof(data), |
1333 | gup_flags: FOLL_FORCE | FOLL_WRITE); |
1334 | return (copied == sizeof(data)) ? 0 : -EIO; |
1335 | } |
1336 | |
1337 | #if defined CONFIG_COMPAT |
1338 | |
1339 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, |
1340 | compat_ulong_t addr, compat_ulong_t data) |
1341 | { |
1342 | compat_ulong_t __user *datap = compat_ptr(uptr: data); |
1343 | compat_ulong_t word; |
1344 | kernel_siginfo_t siginfo; |
1345 | int ret; |
1346 | |
1347 | switch (request) { |
1348 | case PTRACE_PEEKTEXT: |
1349 | case PTRACE_PEEKDATA: |
1350 | ret = ptrace_access_vm(tsk: child, addr, buf: &word, len: sizeof(word), |
1351 | gup_flags: FOLL_FORCE); |
1352 | if (ret != sizeof(word)) |
1353 | ret = -EIO; |
1354 | else |
1355 | ret = put_user(word, datap); |
1356 | break; |
1357 | |
1358 | case PTRACE_POKETEXT: |
1359 | case PTRACE_POKEDATA: |
1360 | ret = ptrace_access_vm(tsk: child, addr, buf: &data, len: sizeof(data), |
1361 | gup_flags: FOLL_FORCE | FOLL_WRITE); |
1362 | ret = (ret != sizeof(data) ? -EIO : 0); |
1363 | break; |
1364 | |
1365 | case PTRACE_GETEVENTMSG: |
1366 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); |
1367 | break; |
1368 | |
1369 | case PTRACE_GETSIGINFO: |
1370 | ret = ptrace_getsiginfo(child, info: &siginfo); |
1371 | if (!ret) |
1372 | ret = copy_siginfo_to_user32( |
1373 | to: (struct compat_siginfo __user *) datap, |
1374 | from: &siginfo); |
1375 | break; |
1376 | |
1377 | case PTRACE_SETSIGINFO: |
1378 | ret = copy_siginfo_from_user32( |
1379 | to: &siginfo, from: (struct compat_siginfo __user *) datap); |
1380 | if (!ret) |
1381 | ret = ptrace_setsiginfo(child, info: &siginfo); |
1382 | break; |
1383 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
1384 | case PTRACE_GETREGSET: |
1385 | case PTRACE_SETREGSET: |
1386 | { |
1387 | struct iovec kiov; |
1388 | struct compat_iovec __user *uiov = |
1389 | (struct compat_iovec __user *) datap; |
1390 | compat_uptr_t ptr; |
1391 | compat_size_t len; |
1392 | |
1393 | if (!access_ok(uiov, sizeof(*uiov))) |
1394 | return -EFAULT; |
1395 | |
1396 | if (__get_user(ptr, &uiov->iov_base) || |
1397 | __get_user(len, &uiov->iov_len)) |
1398 | return -EFAULT; |
1399 | |
1400 | kiov.iov_base = compat_ptr(uptr: ptr); |
1401 | kiov.iov_len = len; |
1402 | |
1403 | ret = ptrace_regset(task: child, req: request, type: addr, kiov: &kiov); |
1404 | if (!ret) |
1405 | ret = __put_user(kiov.iov_len, &uiov->iov_len); |
1406 | break; |
1407 | } |
1408 | #endif |
1409 | |
1410 | default: |
1411 | ret = ptrace_request(child, request, addr, data); |
1412 | } |
1413 | |
1414 | return ret; |
1415 | } |
1416 | |
1417 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, |
1418 | compat_long_t, addr, compat_long_t, data) |
1419 | { |
1420 | struct task_struct *child; |
1421 | long ret; |
1422 | |
1423 | if (request == PTRACE_TRACEME) { |
1424 | ret = ptrace_traceme(); |
1425 | goto out; |
1426 | } |
1427 | |
1428 | child = find_get_task_by_vpid(nr: pid); |
1429 | if (!child) { |
1430 | ret = -ESRCH; |
1431 | goto out; |
1432 | } |
1433 | |
1434 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { |
1435 | ret = ptrace_attach(task: child, request, addr, flags: data); |
1436 | goto out_put_task_struct; |
1437 | } |
1438 | |
1439 | ret = ptrace_check_attach(child, ignore_state: request == PTRACE_KILL || |
1440 | request == PTRACE_INTERRUPT); |
1441 | if (!ret) { |
1442 | ret = compat_arch_ptrace(child, request, addr, data); |
1443 | if (ret || request != PTRACE_DETACH) |
1444 | ptrace_unfreeze_traced(task: child); |
1445 | } |
1446 | |
1447 | out_put_task_struct: |
1448 | put_task_struct(t: child); |
1449 | out: |
1450 | return ret; |
1451 | } |
1452 | #endif /* CONFIG_COMPAT */ |
1453 | |