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