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