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 */
44int 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
69void __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 */
84static 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 */
117void __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
163static 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 */
184static 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
203static 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 */
239static 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
268static 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. */
276static 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;
328ok:
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
349bool 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
358static 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: &current->seccomp) != SECCOMP_MODE_DISABLED ||
372 current->ptrace & PT_SUSPEND_SECCOMP)
373 return -EPERM;
374 }
375 return 0;
376}
377
378static 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
409static 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 */
487static 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 */
513static 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 */
538static 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
563static 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 */
594void 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
607int 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
633int 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
659static 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
677static 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
693static 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
709static 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
792static 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
823static 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
873static const struct user_regset *
874find_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
888static 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 */
915EXPORT_SYMBOL_GPL(task_user_regset_view);
916
917static unsigned long
918ptrace_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->entry.nr = syscall_get_nr(task: child, regs);
925 syscall_get_arguments(task: child, regs, args);
926 for (i = 0; i < ARRAY_SIZE(args); i++)
927 info->entry.args[i] = args[i];
928
929 /* args is the last field in struct ptrace_syscall_info.entry */
930 return offsetofend(struct ptrace_syscall_info, entry.args);
931}
932
933static unsigned long
934ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs,
935 struct ptrace_syscall_info *info)
936{
937 /*
938 * As struct ptrace_syscall_info.entry is currently a subset
939 * of struct ptrace_syscall_info.seccomp, it makes sense to
940 * initialize that subset using ptrace_get_syscall_info_entry().
941 * This can be reconsidered in the future if these structures
942 * diverge significantly enough.
943 */
944 ptrace_get_syscall_info_entry(child, regs, info);
945 info->seccomp.ret_data = child->ptrace_message;
946
947 /*
948 * ret_data is the last non-reserved field
949 * in struct ptrace_syscall_info.seccomp
950 */
951 return offsetofend(struct ptrace_syscall_info, seccomp.ret_data);
952}
953
954static unsigned long
955ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,
956 struct ptrace_syscall_info *info)
957{
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
967static int
968ptrace_get_syscall_info_op(struct task_struct *child)
969{
970 /*
971 * This does not need lock_task_sighand() to access
972 * child->last_siginfo because ptrace_freeze_traced()
973 * called earlier by ptrace_check_attach() ensures that
974 * the tracee cannot go away and clear its last_siginfo.
975 */
976 switch (child->last_siginfo ? child->last_siginfo->si_code : 0) {
977 case SIGTRAP | 0x80:
978 switch (child->ptrace_message) {
979 case PTRACE_EVENTMSG_SYSCALL_ENTRY:
980 return PTRACE_SYSCALL_INFO_ENTRY;
981 case PTRACE_EVENTMSG_SYSCALL_EXIT:
982 return PTRACE_SYSCALL_INFO_EXIT;
983 default:
984 return PTRACE_SYSCALL_INFO_NONE;
985 }
986 case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8):
987 return PTRACE_SYSCALL_INFO_SECCOMP;
988 default:
989 return PTRACE_SYSCALL_INFO_NONE;
990 }
991}
992
993static int
994ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,
995 void __user *datavp)
996{
997 struct pt_regs *regs = task_pt_regs(child);
998 struct ptrace_syscall_info info = {
999 .op = ptrace_get_syscall_info_op(child),
1000 .arch = syscall_get_arch(task: child),
1001 .instruction_pointer = instruction_pointer(regs),
1002 .stack_pointer = user_stack_pointer(regs),
1003 };
1004 unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);
1005 unsigned long write_size;
1006
1007 switch (info.op) {
1008 case PTRACE_SYSCALL_INFO_ENTRY:
1009 actual_size = ptrace_get_syscall_info_entry(child, regs, info: &info);
1010 break;
1011 case PTRACE_SYSCALL_INFO_EXIT:
1012 actual_size = ptrace_get_syscall_info_exit(child, regs, info: &info);
1013 break;
1014 case PTRACE_SYSCALL_INFO_SECCOMP:
1015 actual_size = ptrace_get_syscall_info_seccomp(child, regs, info: &info);
1016 break;
1017 }
1018
1019 write_size = min(actual_size, user_size);
1020 return copy_to_user(to: datavp, from: &info, n: write_size) ? -EFAULT : actual_size;
1021}
1022
1023static int
1024ptrace_set_syscall_info_entry(struct task_struct *child, struct pt_regs *regs,
1025 struct ptrace_syscall_info *info)
1026{
1027 unsigned long args[ARRAY_SIZE(info->entry.args)];
1028 int nr = info->entry.nr;
1029 int i;
1030
1031 /*
1032 * Check that the syscall number specified in info->entry.nr
1033 * is either a value of type "int" or a sign-extended value
1034 * of type "int".
1035 */
1036 if (nr != info->entry.nr)
1037 return -ERANGE;
1038
1039 for (i = 0; i < ARRAY_SIZE(args); i++) {
1040 args[i] = info->entry.args[i];
1041 /*
1042 * Check that the syscall argument specified in
1043 * info->entry.args[i] is either a value of type
1044 * "unsigned long" or a sign-extended value of type "long".
1045 */
1046 if (args[i] != info->entry.args[i])
1047 return -ERANGE;
1048 }
1049
1050 syscall_set_nr(task: child, regs, nr);
1051 /*
1052 * If the syscall number is set to -1, setting syscall arguments is not
1053 * just pointless, it would also clobber the syscall return value on
1054 * those architectures that share the same register both for the first
1055 * argument of syscall and its return value.
1056 */
1057 if (nr != -1)
1058 syscall_set_arguments(task: child, regs, args);
1059
1060 return 0;
1061}
1062
1063static int
1064ptrace_set_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs,
1065 struct ptrace_syscall_info *info)
1066{
1067 /*
1068 * info->entry is currently a subset of info->seccomp,
1069 * info->seccomp.ret_data is currently ignored.
1070 */
1071 return ptrace_set_syscall_info_entry(child, regs, info);
1072}
1073
1074static int
1075ptrace_set_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,
1076 struct ptrace_syscall_info *info)
1077{
1078 long rval = info->exit.rval;
1079
1080 /*
1081 * Check that the return value specified in info->exit.rval
1082 * is either a value of type "long" or a sign-extended value
1083 * of type "long".
1084 */
1085 if (rval != info->exit.rval)
1086 return -ERANGE;
1087
1088 if (info->exit.is_error)
1089 syscall_set_return_value(task: child, regs, error: rval, val: 0);
1090 else
1091 syscall_set_return_value(task: child, regs, error: 0, val: rval);
1092
1093 return 0;
1094}
1095
1096static int
1097ptrace_set_syscall_info(struct task_struct *child, unsigned long user_size,
1098 const void __user *datavp)
1099{
1100 struct pt_regs *regs = task_pt_regs(child);
1101 struct ptrace_syscall_info info;
1102
1103 if (user_size < sizeof(info))
1104 return -EINVAL;
1105
1106 /*
1107 * The compatibility is tracked by info.op and info.flags: if user-space
1108 * does not instruct us to use unknown extra bits from future versions
1109 * of ptrace_syscall_info, we are not going to read them either.
1110 */
1111 if (copy_from_user(to: &info, from: datavp, n: sizeof(info)))
1112 return -EFAULT;
1113
1114 /* Reserved for future use. */
1115 if (info.flags || info.reserved)
1116 return -EINVAL;
1117
1118 /* Changing the type of the system call stop is not supported yet. */
1119 if (ptrace_get_syscall_info_op(child) != info.op)
1120 return -EINVAL;
1121
1122 switch (info.op) {
1123 case PTRACE_SYSCALL_INFO_ENTRY:
1124 return ptrace_set_syscall_info_entry(child, regs, info: &info);
1125 case PTRACE_SYSCALL_INFO_EXIT:
1126 return ptrace_set_syscall_info_exit(child, regs, info: &info);
1127 case PTRACE_SYSCALL_INFO_SECCOMP:
1128 return ptrace_set_syscall_info_seccomp(child, regs, info: &info);
1129 default:
1130 /* Other types of system call stops are not supported yet. */
1131 return -EINVAL;
1132 }
1133}
1134#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
1135
1136int ptrace_request(struct task_struct *child, long request,
1137 unsigned long addr, unsigned long data)
1138{
1139 bool seized = child->ptrace & PT_SEIZED;
1140 int ret = -EIO;
1141 kernel_siginfo_t siginfo, *si;
1142 void __user *datavp = (void __user *) data;
1143 unsigned long __user *datalp = datavp;
1144 unsigned long flags;
1145
1146 switch (request) {
1147 case PTRACE_PEEKTEXT:
1148 case PTRACE_PEEKDATA:
1149 return generic_ptrace_peekdata(tsk: child, addr, data);
1150 case PTRACE_POKETEXT:
1151 case PTRACE_POKEDATA:
1152 return generic_ptrace_pokedata(tsk: child, addr, data);
1153
1154#ifdef PTRACE_OLDSETOPTIONS
1155 case PTRACE_OLDSETOPTIONS:
1156#endif
1157 case PTRACE_SETOPTIONS:
1158 ret = ptrace_setoptions(child, data);
1159 break;
1160 case PTRACE_GETEVENTMSG:
1161 ret = put_user(child->ptrace_message, datalp);
1162 break;
1163
1164 case PTRACE_PEEKSIGINFO:
1165 ret = ptrace_peek_siginfo(child, addr, data);
1166 break;
1167
1168 case PTRACE_GETSIGINFO:
1169 ret = ptrace_getsiginfo(child, info: &siginfo);
1170 if (!ret)
1171 ret = copy_siginfo_to_user(to: datavp, from: &siginfo);
1172 break;
1173
1174 case PTRACE_SETSIGINFO:
1175 ret = copy_siginfo_from_user(to: &siginfo, from: datavp);
1176 if (!ret)
1177 ret = ptrace_setsiginfo(child, info: &siginfo);
1178 break;
1179
1180 case PTRACE_GETSIGMASK: {
1181 sigset_t *mask;
1182
1183 if (addr != sizeof(sigset_t)) {
1184 ret = -EINVAL;
1185 break;
1186 }
1187
1188 if (test_tsk_restore_sigmask(task: child))
1189 mask = &child->saved_sigmask;
1190 else
1191 mask = &child->blocked;
1192
1193 if (copy_to_user(to: datavp, from: mask, n: sizeof(sigset_t)))
1194 ret = -EFAULT;
1195 else
1196 ret = 0;
1197
1198 break;
1199 }
1200
1201 case PTRACE_SETSIGMASK: {
1202 sigset_t new_set;
1203
1204 if (addr != sizeof(sigset_t)) {
1205 ret = -EINVAL;
1206 break;
1207 }
1208
1209 if (copy_from_user(to: &new_set, from: datavp, n: sizeof(sigset_t))) {
1210 ret = -EFAULT;
1211 break;
1212 }
1213
1214 sigdelsetmask(set: &new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
1215
1216 /*
1217 * Every thread does recalc_sigpending() after resume, so
1218 * retarget_shared_pending() and recalc_sigpending() are not
1219 * called here.
1220 */
1221 spin_lock_irq(lock: &child->sighand->siglock);
1222 child->blocked = new_set;
1223 spin_unlock_irq(lock: &child->sighand->siglock);
1224
1225 clear_tsk_restore_sigmask(task: child);
1226
1227 ret = 0;
1228 break;
1229 }
1230
1231 case PTRACE_INTERRUPT:
1232 /*
1233 * Stop tracee without any side-effect on signal or job
1234 * control. At least one trap is guaranteed to happen
1235 * after this request. If @child is already trapped, the
1236 * current trap is not disturbed and another trap will
1237 * happen after the current trap is ended with PTRACE_CONT.
1238 *
1239 * The actual trap might not be PTRACE_EVENT_STOP trap but
1240 * the pending condition is cleared regardless.
1241 */
1242 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1243 break;
1244
1245 /*
1246 * INTERRUPT doesn't disturb existing trap sans one
1247 * exception. If ptracer issued LISTEN for the current
1248 * STOP, this INTERRUPT should clear LISTEN and re-trap
1249 * tracee into STOP.
1250 */
1251 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1252 ptrace_signal_wake_up(t: child, resume: child->jobctl & JOBCTL_LISTENING);
1253
1254 unlock_task_sighand(task: child, flags: &flags);
1255 ret = 0;
1256 break;
1257
1258 case PTRACE_LISTEN:
1259 /*
1260 * Listen for events. Tracee must be in STOP. It's not
1261 * resumed per-se but is not considered to be in TRACED by
1262 * wait(2) or ptrace(2). If an async event (e.g. group
1263 * stop state change) happens, tracee will enter STOP trap
1264 * again. Alternatively, ptracer can issue INTERRUPT to
1265 * finish listening and re-trap tracee into STOP.
1266 */
1267 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1268 break;
1269
1270 si = child->last_siginfo;
1271 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1272 child->jobctl |= JOBCTL_LISTENING;
1273 /*
1274 * If NOTIFY is set, it means event happened between
1275 * start of this trap and now. Trigger re-trap.
1276 */
1277 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1278 ptrace_signal_wake_up(t: child, resume: true);
1279 ret = 0;
1280 }
1281 unlock_task_sighand(task: child, flags: &flags);
1282 break;
1283
1284 case PTRACE_DETACH: /* detach a process that was attached. */
1285 ret = ptrace_detach(child, data);
1286 break;
1287
1288#ifdef CONFIG_BINFMT_ELF_FDPIC
1289 case PTRACE_GETFDPIC: {
1290 struct mm_struct *mm = get_task_mm(child);
1291 unsigned long tmp = 0;
1292
1293 ret = -ESRCH;
1294 if (!mm)
1295 break;
1296
1297 switch (addr) {
1298 case PTRACE_GETFDPIC_EXEC:
1299 tmp = mm->context.exec_fdpic_loadmap;
1300 break;
1301 case PTRACE_GETFDPIC_INTERP:
1302 tmp = mm->context.interp_fdpic_loadmap;
1303 break;
1304 default:
1305 break;
1306 }
1307 mmput(mm);
1308
1309 ret = put_user(tmp, datalp);
1310 break;
1311 }
1312#endif
1313
1314 case PTRACE_SINGLESTEP:
1315#ifdef PTRACE_SINGLEBLOCK
1316 case PTRACE_SINGLEBLOCK:
1317#endif
1318#ifdef PTRACE_SYSEMU
1319 case PTRACE_SYSEMU:
1320 case PTRACE_SYSEMU_SINGLESTEP:
1321#endif
1322 case PTRACE_SYSCALL:
1323 case PTRACE_CONT:
1324 return ptrace_resume(child, request, data);
1325
1326 case PTRACE_KILL:
1327 send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
1328 return 0;
1329
1330#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1331 case PTRACE_GETREGSET:
1332 case PTRACE_SETREGSET: {
1333 struct iovec kiov;
1334 struct iovec __user *uiov = datavp;
1335
1336 if (!access_ok(uiov, sizeof(*uiov)))
1337 return -EFAULT;
1338
1339 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1340 __get_user(kiov.iov_len, &uiov->iov_len))
1341 return -EFAULT;
1342
1343 ret = ptrace_regset(task: child, req: request, type: addr, kiov: &kiov);
1344 if (!ret)
1345 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1346 break;
1347 }
1348
1349 case PTRACE_GET_SYSCALL_INFO:
1350 ret = ptrace_get_syscall_info(child, user_size: addr, datavp);
1351 break;
1352
1353 case PTRACE_SET_SYSCALL_INFO:
1354 ret = ptrace_set_syscall_info(child, user_size: addr, datavp);
1355 break;
1356#endif
1357
1358 case PTRACE_SECCOMP_GET_FILTER:
1359 ret = seccomp_get_filter(task: child, n: addr, data: datavp);
1360 break;
1361
1362 case PTRACE_SECCOMP_GET_METADATA:
1363 ret = seccomp_get_metadata(task: child, filter_off: addr, data: datavp);
1364 break;
1365
1366#ifdef CONFIG_RSEQ
1367 case PTRACE_GET_RSEQ_CONFIGURATION:
1368 ret = ptrace_get_rseq_configuration(task: child, size: addr, data: datavp);
1369 break;
1370#endif
1371
1372 case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG:
1373 ret = syscall_user_dispatch_set_config(task: child, size: addr, data: datavp);
1374 break;
1375
1376 case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG:
1377 ret = syscall_user_dispatch_get_config(task: child, size: addr, data: datavp);
1378 break;
1379
1380 default:
1381 break;
1382 }
1383
1384 return ret;
1385}
1386
1387SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1388 unsigned long, data)
1389{
1390 struct task_struct *child;
1391 long ret;
1392
1393 if (request == PTRACE_TRACEME) {
1394 ret = ptrace_traceme();
1395 goto out;
1396 }
1397
1398 child = find_get_task_by_vpid(nr: pid);
1399 if (!child) {
1400 ret = -ESRCH;
1401 goto out;
1402 }
1403
1404 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1405 ret = ptrace_attach(task: child, request, addr, flags: data);
1406 goto out_put_task_struct;
1407 }
1408
1409 ret = ptrace_check_attach(child, ignore_state: request == PTRACE_KILL ||
1410 request == PTRACE_INTERRUPT);
1411 if (ret < 0)
1412 goto out_put_task_struct;
1413
1414 ret = arch_ptrace(child, request, addr, data);
1415 if (ret || request != PTRACE_DETACH)
1416 ptrace_unfreeze_traced(task: child);
1417
1418 out_put_task_struct:
1419 put_task_struct(t: child);
1420 out:
1421 return ret;
1422}
1423
1424int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1425 unsigned long data)
1426{
1427 unsigned long tmp;
1428 int copied;
1429
1430 copied = ptrace_access_vm(tsk, addr, buf: &tmp, len: sizeof(tmp), gup_flags: FOLL_FORCE);
1431 if (copied != sizeof(tmp))
1432 return -EIO;
1433 return put_user(tmp, (unsigned long __user *)data);
1434}
1435
1436int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1437 unsigned long data)
1438{
1439 int copied;
1440
1441 copied = ptrace_access_vm(tsk, addr, buf: &data, len: sizeof(data),
1442 gup_flags: FOLL_FORCE | FOLL_WRITE);
1443 return (copied == sizeof(data)) ? 0 : -EIO;
1444}
1445
1446#if defined CONFIG_COMPAT
1447
1448int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1449 compat_ulong_t addr, compat_ulong_t data)
1450{
1451 compat_ulong_t __user *datap = compat_ptr(uptr: data);
1452 compat_ulong_t word;
1453 kernel_siginfo_t siginfo;
1454 int ret;
1455
1456 switch (request) {
1457 case PTRACE_PEEKTEXT:
1458 case PTRACE_PEEKDATA:
1459 ret = ptrace_access_vm(tsk: child, addr, buf: &word, len: sizeof(word),
1460 gup_flags: FOLL_FORCE);
1461 if (ret != sizeof(word))
1462 ret = -EIO;
1463 else
1464 ret = put_user(word, datap);
1465 break;
1466
1467 case PTRACE_POKETEXT:
1468 case PTRACE_POKEDATA:
1469 ret = ptrace_access_vm(tsk: child, addr, buf: &data, len: sizeof(data),
1470 gup_flags: FOLL_FORCE | FOLL_WRITE);
1471 ret = (ret != sizeof(data) ? -EIO : 0);
1472 break;
1473
1474 case PTRACE_GETEVENTMSG:
1475 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1476 break;
1477
1478 case PTRACE_GETSIGINFO:
1479 ret = ptrace_getsiginfo(child, info: &siginfo);
1480 if (!ret)
1481 ret = copy_siginfo_to_user32(
1482 to: (struct compat_siginfo __user *) datap,
1483 from: &siginfo);
1484 break;
1485
1486 case PTRACE_SETSIGINFO:
1487 ret = copy_siginfo_from_user32(
1488 to: &siginfo, from: (struct compat_siginfo __user *) datap);
1489 if (!ret)
1490 ret = ptrace_setsiginfo(child, info: &siginfo);
1491 break;
1492#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1493 case PTRACE_GETREGSET:
1494 case PTRACE_SETREGSET:
1495 {
1496 struct iovec kiov;
1497 struct compat_iovec __user *uiov =
1498 (struct compat_iovec __user *) datap;
1499 compat_uptr_t ptr;
1500 compat_size_t len;
1501
1502 if (!access_ok(uiov, sizeof(*uiov)))
1503 return -EFAULT;
1504
1505 if (__get_user(ptr, &uiov->iov_base) ||
1506 __get_user(len, &uiov->iov_len))
1507 return -EFAULT;
1508
1509 kiov.iov_base = compat_ptr(uptr: ptr);
1510 kiov.iov_len = len;
1511
1512 ret = ptrace_regset(task: child, req: request, type: addr, kiov: &kiov);
1513 if (!ret)
1514 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1515 break;
1516 }
1517#endif
1518
1519 default:
1520 ret = ptrace_request(child, request, addr, data);
1521 }
1522
1523 return ret;
1524}
1525
1526COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1527 compat_long_t, addr, compat_long_t, data)
1528{
1529 struct task_struct *child;
1530 long ret;
1531
1532 if (request == PTRACE_TRACEME) {
1533 ret = ptrace_traceme();
1534 goto out;
1535 }
1536
1537 child = find_get_task_by_vpid(nr: pid);
1538 if (!child) {
1539 ret = -ESRCH;
1540 goto out;
1541 }
1542
1543 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1544 ret = ptrace_attach(task: child, request, addr, flags: data);
1545 goto out_put_task_struct;
1546 }
1547
1548 ret = ptrace_check_attach(child, ignore_state: request == PTRACE_KILL ||
1549 request == PTRACE_INTERRUPT);
1550 if (!ret) {
1551 ret = compat_arch_ptrace(child, request, addr, data);
1552 if (ret || request != PTRACE_DETACH)
1553 ptrace_unfreeze_traced(task: child);
1554 }
1555
1556 out_put_task_struct:
1557 put_task_struct(t: child);
1558 out:
1559 return ret;
1560}
1561#endif /* CONFIG_COMPAT */
1562