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