1 /* 2 * linux/kernel/ptrace.c 3 * 4 * (C) Copyright 1999 Linus Torvalds 5 * 6 * Common interfaces for "ptrace()" which we do not want 7 * to continually duplicate across every architecture. 8 */ 9 10 #include <linux/capability.h> 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/errno.h> 14 #include <linux/mm.h> 15 #include <linux/highmem.h> 16 #include <linux/pagemap.h> 17 #include <linux/ptrace.h> 18 #include <linux/security.h> 19 #include <linux/signal.h> 20 #include <linux/audit.h> 21 #include <linux/pid_namespace.h> 22 #include <linux/syscalls.h> 23 #include <linux/uaccess.h> 24 #include <linux/regset.h> 25 26 27 /* 28 * ptrace a task: make the debugger its new parent and 29 * move it to the ptrace list. 30 * 31 * Must be called with the tasklist lock write-held. 32 */ 33 void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 34 { 35 BUG_ON(!list_empty(&child->ptrace_entry)); 36 list_add(&child->ptrace_entry, &new_parent->ptraced); 37 child->parent = new_parent; 38 } 39 40 /* 41 * Turn a tracing stop into a normal stop now, since with no tracer there 42 * would be no way to wake it up with SIGCONT or SIGKILL. If there was a 43 * signal sent that would resume the child, but didn't because it was in 44 * TASK_TRACED, resume it now. 45 * Requires that irqs be disabled. 46 */ 47 static void ptrace_untrace(struct task_struct *child) 48 { 49 spin_lock(&child->sighand->siglock); 50 if (task_is_traced(child)) { 51 /* 52 * If the group stop is completed or in progress, 53 * this thread was already counted as stopped. 54 */ 55 if (child->signal->flags & SIGNAL_STOP_STOPPED || 56 child->signal->group_stop_count) 57 __set_task_state(child, TASK_STOPPED); 58 else 59 signal_wake_up(child, 1); 60 } 61 spin_unlock(&child->sighand->siglock); 62 } 63 64 /* 65 * unptrace a task: move it back to its original parent and 66 * remove it from the ptrace list. 67 * 68 * Must be called with the tasklist lock write-held. 69 */ 70 void __ptrace_unlink(struct task_struct *child) 71 { 72 BUG_ON(!child->ptrace); 73 74 child->ptrace = 0; 75 child->parent = child->real_parent; 76 list_del_init(&child->ptrace_entry); 77 78 if (task_is_traced(child)) 79 ptrace_untrace(child); 80 } 81 82 /* 83 * Check that we have indeed attached to the thing.. 84 */ 85 int ptrace_check_attach(struct task_struct *child, int kill) 86 { 87 int ret = -ESRCH; 88 89 /* 90 * We take the read lock around doing both checks to close a 91 * possible race where someone else was tracing our child and 92 * detached between these two checks. After this locked check, 93 * we are sure that this is our traced child and that can only 94 * be changed by us so it's not changing right after this. 95 */ 96 read_lock(&tasklist_lock); 97 if ((child->ptrace & PT_PTRACED) && child->parent == current) { 98 ret = 0; 99 /* 100 * child->sighand can't be NULL, release_task() 101 * does ptrace_unlink() before __exit_signal(). 102 */ 103 spin_lock_irq(&child->sighand->siglock); 104 if (task_is_stopped(child)) 105 child->state = TASK_TRACED; 106 else if (!task_is_traced(child) && !kill) 107 ret = -ESRCH; 108 spin_unlock_irq(&child->sighand->siglock); 109 } 110 read_unlock(&tasklist_lock); 111 112 if (!ret && !kill) 113 ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 114 115 /* All systems go.. */ 116 return ret; 117 } 118 119 int __ptrace_may_access(struct task_struct *task, unsigned int mode) 120 { 121 const struct cred *cred = current_cred(), *tcred; 122 123 /* May we inspect the given task? 124 * This check is used both for attaching with ptrace 125 * and for allowing access to sensitive information in /proc. 126 * 127 * ptrace_attach denies several cases that /proc allows 128 * because setting up the necessary parent/child relationship 129 * or halting the specified task is impossible. 130 */ 131 int dumpable = 0; 132 /* Don't let security modules deny introspection */ 133 if (task == current) 134 return 0; 135 rcu_read_lock(); 136 tcred = __task_cred(task); 137 if ((cred->uid != tcred->euid || 138 cred->uid != tcred->suid || 139 cred->uid != tcred->uid || 140 cred->gid != tcred->egid || 141 cred->gid != tcred->sgid || 142 cred->gid != tcred->gid) && 143 !capable(CAP_SYS_PTRACE)) { 144 rcu_read_unlock(); 145 return -EPERM; 146 } 147 rcu_read_unlock(); 148 smp_rmb(); 149 if (task->mm) 150 dumpable = get_dumpable(task->mm); 151 if (!dumpable && !capable(CAP_SYS_PTRACE)) 152 return -EPERM; 153 154 return security_ptrace_access_check(task, mode); 155 } 156 157 bool ptrace_may_access(struct task_struct *task, unsigned int mode) 158 { 159 int err; 160 task_lock(task); 161 err = __ptrace_may_access(task, mode); 162 task_unlock(task); 163 return !err; 164 } 165 166 int ptrace_attach(struct task_struct *task) 167 { 168 int retval; 169 170 audit_ptrace(task); 171 172 retval = -EPERM; 173 if (unlikely(task->flags & PF_KTHREAD)) 174 goto out; 175 if (same_thread_group(task, current)) 176 goto out; 177 178 /* 179 * Protect exec's credential calculations against our interference; 180 * interference; SUID, SGID and LSM creds get determined differently 181 * under ptrace. 182 */ 183 retval = -ERESTARTNOINTR; 184 if (mutex_lock_interruptible(&task->cred_guard_mutex)) 185 goto out; 186 187 task_lock(task); 188 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 189 task_unlock(task); 190 if (retval) 191 goto unlock_creds; 192 193 write_lock_irq(&tasklist_lock); 194 retval = -EPERM; 195 if (unlikely(task->exit_state)) 196 goto unlock_tasklist; 197 if (task->ptrace) 198 goto unlock_tasklist; 199 200 task->ptrace = PT_PTRACED; 201 if (capable(CAP_SYS_PTRACE)) 202 task->ptrace |= PT_PTRACE_CAP; 203 204 __ptrace_link(task, current); 205 send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 206 207 retval = 0; 208 unlock_tasklist: 209 write_unlock_irq(&tasklist_lock); 210 unlock_creds: 211 mutex_unlock(&task->cred_guard_mutex); 212 out: 213 return retval; 214 } 215 216 /** 217 * ptrace_traceme -- helper for PTRACE_TRACEME 218 * 219 * Performs checks and sets PT_PTRACED. 220 * Should be used by all ptrace implementations for PTRACE_TRACEME. 221 */ 222 int ptrace_traceme(void) 223 { 224 int ret = -EPERM; 225 226 write_lock_irq(&tasklist_lock); 227 /* Are we already being traced? */ 228 if (!current->ptrace) { 229 ret = security_ptrace_traceme(current->parent); 230 /* 231 * Check PF_EXITING to ensure ->real_parent has not passed 232 * exit_ptrace(). Otherwise we don't report the error but 233 * pretend ->real_parent untraces us right after return. 234 */ 235 if (!ret && !(current->real_parent->flags & PF_EXITING)) { 236 current->ptrace = PT_PTRACED; 237 __ptrace_link(current, current->real_parent); 238 } 239 } 240 write_unlock_irq(&tasklist_lock); 241 242 return ret; 243 } 244 245 /* 246 * Called with irqs disabled, returns true if childs should reap themselves. 247 */ 248 static int ignoring_children(struct sighand_struct *sigh) 249 { 250 int ret; 251 spin_lock(&sigh->siglock); 252 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 253 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 254 spin_unlock(&sigh->siglock); 255 return ret; 256 } 257 258 /* 259 * Called with tasklist_lock held for writing. 260 * Unlink a traced task, and clean it up if it was a traced zombie. 261 * Return true if it needs to be reaped with release_task(). 262 * (We can't call release_task() here because we already hold tasklist_lock.) 263 * 264 * If it's a zombie, our attachedness prevented normal parent notification 265 * or self-reaping. Do notification now if it would have happened earlier. 266 * If it should reap itself, return true. 267 * 268 * If it's our own child, there is no notification to do. But if our normal 269 * children self-reap, then this child was prevented by ptrace and we must 270 * reap it now, in that case we must also wake up sub-threads sleeping in 271 * do_wait(). 272 */ 273 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 274 { 275 __ptrace_unlink(p); 276 277 if (p->exit_state == EXIT_ZOMBIE) { 278 if (!task_detached(p) && thread_group_empty(p)) { 279 if (!same_thread_group(p->real_parent, tracer)) 280 do_notify_parent(p, p->exit_signal); 281 else if (ignoring_children(tracer->sighand)) { 282 __wake_up_parent(p, tracer); 283 p->exit_signal = -1; 284 } 285 } 286 if (task_detached(p)) { 287 /* Mark it as in the process of being reaped. */ 288 p->exit_state = EXIT_DEAD; 289 return true; 290 } 291 } 292 293 return false; 294 } 295 296 int ptrace_detach(struct task_struct *child, unsigned int data) 297 { 298 bool dead = false; 299 300 if (!valid_signal(data)) 301 return -EIO; 302 303 /* Architecture-specific hardware disable .. */ 304 ptrace_disable(child); 305 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 306 307 write_lock_irq(&tasklist_lock); 308 /* 309 * This child can be already killed. Make sure de_thread() or 310 * our sub-thread doing do_wait() didn't do release_task() yet. 311 */ 312 if (child->ptrace) { 313 child->exit_code = data; 314 dead = __ptrace_detach(current, child); 315 if (!child->exit_state) 316 wake_up_process(child); 317 } 318 write_unlock_irq(&tasklist_lock); 319 320 if (unlikely(dead)) 321 release_task(child); 322 323 return 0; 324 } 325 326 /* 327 * Detach all tasks we were using ptrace on. 328 */ 329 void exit_ptrace(struct task_struct *tracer) 330 { 331 struct task_struct *p, *n; 332 LIST_HEAD(ptrace_dead); 333 334 write_lock_irq(&tasklist_lock); 335 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 336 if (__ptrace_detach(tracer, p)) 337 list_add(&p->ptrace_entry, &ptrace_dead); 338 } 339 write_unlock_irq(&tasklist_lock); 340 341 BUG_ON(!list_empty(&tracer->ptraced)); 342 343 list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 344 list_del_init(&p->ptrace_entry); 345 release_task(p); 346 } 347 } 348 349 int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 350 { 351 int copied = 0; 352 353 while (len > 0) { 354 char buf[128]; 355 int this_len, retval; 356 357 this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 358 retval = access_process_vm(tsk, src, buf, this_len, 0); 359 if (!retval) { 360 if (copied) 361 break; 362 return -EIO; 363 } 364 if (copy_to_user(dst, buf, retval)) 365 return -EFAULT; 366 copied += retval; 367 src += retval; 368 dst += retval; 369 len -= retval; 370 } 371 return copied; 372 } 373 374 int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 375 { 376 int copied = 0; 377 378 while (len > 0) { 379 char buf[128]; 380 int this_len, retval; 381 382 this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 383 if (copy_from_user(buf, src, this_len)) 384 return -EFAULT; 385 retval = access_process_vm(tsk, dst, buf, this_len, 1); 386 if (!retval) { 387 if (copied) 388 break; 389 return -EIO; 390 } 391 copied += retval; 392 src += retval; 393 dst += retval; 394 len -= retval; 395 } 396 return copied; 397 } 398 399 static int ptrace_setoptions(struct task_struct *child, long data) 400 { 401 child->ptrace &= ~PT_TRACE_MASK; 402 403 if (data & PTRACE_O_TRACESYSGOOD) 404 child->ptrace |= PT_TRACESYSGOOD; 405 406 if (data & PTRACE_O_TRACEFORK) 407 child->ptrace |= PT_TRACE_FORK; 408 409 if (data & PTRACE_O_TRACEVFORK) 410 child->ptrace |= PT_TRACE_VFORK; 411 412 if (data & PTRACE_O_TRACECLONE) 413 child->ptrace |= PT_TRACE_CLONE; 414 415 if (data & PTRACE_O_TRACEEXEC) 416 child->ptrace |= PT_TRACE_EXEC; 417 418 if (data & PTRACE_O_TRACEVFORKDONE) 419 child->ptrace |= PT_TRACE_VFORK_DONE; 420 421 if (data & PTRACE_O_TRACEEXIT) 422 child->ptrace |= PT_TRACE_EXIT; 423 424 return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 425 } 426 427 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 428 { 429 unsigned long flags; 430 int error = -ESRCH; 431 432 if (lock_task_sighand(child, &flags)) { 433 error = -EINVAL; 434 if (likely(child->last_siginfo != NULL)) { 435 *info = *child->last_siginfo; 436 error = 0; 437 } 438 unlock_task_sighand(child, &flags); 439 } 440 return error; 441 } 442 443 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 444 { 445 unsigned long flags; 446 int error = -ESRCH; 447 448 if (lock_task_sighand(child, &flags)) { 449 error = -EINVAL; 450 if (likely(child->last_siginfo != NULL)) { 451 *child->last_siginfo = *info; 452 error = 0; 453 } 454 unlock_task_sighand(child, &flags); 455 } 456 return error; 457 } 458 459 460 #ifdef PTRACE_SINGLESTEP 461 #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 462 #else 463 #define is_singlestep(request) 0 464 #endif 465 466 #ifdef PTRACE_SINGLEBLOCK 467 #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 468 #else 469 #define is_singleblock(request) 0 470 #endif 471 472 #ifdef PTRACE_SYSEMU 473 #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 474 #else 475 #define is_sysemu_singlestep(request) 0 476 #endif 477 478 static int ptrace_resume(struct task_struct *child, long request, long data) 479 { 480 if (!valid_signal(data)) 481 return -EIO; 482 483 if (request == PTRACE_SYSCALL) 484 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 485 else 486 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 487 488 #ifdef TIF_SYSCALL_EMU 489 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 490 set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 491 else 492 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 493 #endif 494 495 if (is_singleblock(request)) { 496 if (unlikely(!arch_has_block_step())) 497 return -EIO; 498 user_enable_block_step(child); 499 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 500 if (unlikely(!arch_has_single_step())) 501 return -EIO; 502 user_enable_single_step(child); 503 } else { 504 user_disable_single_step(child); 505 } 506 507 child->exit_code = data; 508 wake_up_process(child); 509 510 return 0; 511 } 512 513 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 514 515 static const struct user_regset * 516 find_regset(const struct user_regset_view *view, unsigned int type) 517 { 518 const struct user_regset *regset; 519 int n; 520 521 for (n = 0; n < view->n; ++n) { 522 regset = view->regsets + n; 523 if (regset->core_note_type == type) 524 return regset; 525 } 526 527 return NULL; 528 } 529 530 static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 531 struct iovec *kiov) 532 { 533 const struct user_regset_view *view = task_user_regset_view(task); 534 const struct user_regset *regset = find_regset(view, type); 535 int regset_no; 536 537 if (!regset || (kiov->iov_len % regset->size) != 0) 538 return -EINVAL; 539 540 regset_no = regset - view->regsets; 541 kiov->iov_len = min(kiov->iov_len, 542 (__kernel_size_t) (regset->n * regset->size)); 543 544 if (req == PTRACE_GETREGSET) 545 return copy_regset_to_user(task, view, regset_no, 0, 546 kiov->iov_len, kiov->iov_base); 547 else 548 return copy_regset_from_user(task, view, regset_no, 0, 549 kiov->iov_len, kiov->iov_base); 550 } 551 552 #endif 553 554 int ptrace_request(struct task_struct *child, long request, 555 long addr, long data) 556 { 557 int ret = -EIO; 558 siginfo_t siginfo; 559 560 switch (request) { 561 case PTRACE_PEEKTEXT: 562 case PTRACE_PEEKDATA: 563 return generic_ptrace_peekdata(child, addr, data); 564 case PTRACE_POKETEXT: 565 case PTRACE_POKEDATA: 566 return generic_ptrace_pokedata(child, addr, data); 567 568 #ifdef PTRACE_OLDSETOPTIONS 569 case PTRACE_OLDSETOPTIONS: 570 #endif 571 case PTRACE_SETOPTIONS: 572 ret = ptrace_setoptions(child, data); 573 break; 574 case PTRACE_GETEVENTMSG: 575 ret = put_user(child->ptrace_message, (unsigned long __user *) data); 576 break; 577 578 case PTRACE_GETSIGINFO: 579 ret = ptrace_getsiginfo(child, &siginfo); 580 if (!ret) 581 ret = copy_siginfo_to_user((siginfo_t __user *) data, 582 &siginfo); 583 break; 584 585 case PTRACE_SETSIGINFO: 586 if (copy_from_user(&siginfo, (siginfo_t __user *) data, 587 sizeof siginfo)) 588 ret = -EFAULT; 589 else 590 ret = ptrace_setsiginfo(child, &siginfo); 591 break; 592 593 case PTRACE_DETACH: /* detach a process that was attached. */ 594 ret = ptrace_detach(child, data); 595 break; 596 597 #ifdef CONFIG_BINFMT_ELF_FDPIC 598 case PTRACE_GETFDPIC: { 599 struct mm_struct *mm = get_task_mm(child); 600 unsigned long tmp = 0; 601 602 ret = -ESRCH; 603 if (!mm) 604 break; 605 606 switch (addr) { 607 case PTRACE_GETFDPIC_EXEC: 608 tmp = mm->context.exec_fdpic_loadmap; 609 break; 610 case PTRACE_GETFDPIC_INTERP: 611 tmp = mm->context.interp_fdpic_loadmap; 612 break; 613 default: 614 break; 615 } 616 mmput(mm); 617 618 ret = put_user(tmp, (unsigned long __user *) data); 619 break; 620 } 621 #endif 622 623 #ifdef PTRACE_SINGLESTEP 624 case PTRACE_SINGLESTEP: 625 #endif 626 #ifdef PTRACE_SINGLEBLOCK 627 case PTRACE_SINGLEBLOCK: 628 #endif 629 #ifdef PTRACE_SYSEMU 630 case PTRACE_SYSEMU: 631 case PTRACE_SYSEMU_SINGLESTEP: 632 #endif 633 case PTRACE_SYSCALL: 634 case PTRACE_CONT: 635 return ptrace_resume(child, request, data); 636 637 case PTRACE_KILL: 638 if (child->exit_state) /* already dead */ 639 return 0; 640 return ptrace_resume(child, request, SIGKILL); 641 642 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 643 case PTRACE_GETREGSET: 644 case PTRACE_SETREGSET: 645 { 646 struct iovec kiov; 647 struct iovec __user *uiov = (struct iovec __user *) data; 648 649 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 650 return -EFAULT; 651 652 if (__get_user(kiov.iov_base, &uiov->iov_base) || 653 __get_user(kiov.iov_len, &uiov->iov_len)) 654 return -EFAULT; 655 656 ret = ptrace_regset(child, request, addr, &kiov); 657 if (!ret) 658 ret = __put_user(kiov.iov_len, &uiov->iov_len); 659 break; 660 } 661 #endif 662 default: 663 break; 664 } 665 666 return ret; 667 } 668 669 static struct task_struct *ptrace_get_task_struct(pid_t pid) 670 { 671 struct task_struct *child; 672 673 rcu_read_lock(); 674 child = find_task_by_vpid(pid); 675 if (child) 676 get_task_struct(child); 677 rcu_read_unlock(); 678 679 if (!child) 680 return ERR_PTR(-ESRCH); 681 return child; 682 } 683 684 #ifndef arch_ptrace_attach 685 #define arch_ptrace_attach(child) do { } while (0) 686 #endif 687 688 SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) 689 { 690 struct task_struct *child; 691 long ret; 692 693 if (request == PTRACE_TRACEME) { 694 ret = ptrace_traceme(); 695 if (!ret) 696 arch_ptrace_attach(current); 697 goto out; 698 } 699 700 child = ptrace_get_task_struct(pid); 701 if (IS_ERR(child)) { 702 ret = PTR_ERR(child); 703 goto out; 704 } 705 706 if (request == PTRACE_ATTACH) { 707 ret = ptrace_attach(child); 708 /* 709 * Some architectures need to do book-keeping after 710 * a ptrace attach. 711 */ 712 if (!ret) 713 arch_ptrace_attach(child); 714 goto out_put_task_struct; 715 } 716 717 ret = ptrace_check_attach(child, request == PTRACE_KILL); 718 if (ret < 0) 719 goto out_put_task_struct; 720 721 ret = arch_ptrace(child, request, addr, data); 722 723 out_put_task_struct: 724 put_task_struct(child); 725 out: 726 return ret; 727 } 728 729 int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) 730 { 731 unsigned long tmp; 732 int copied; 733 734 copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 735 if (copied != sizeof(tmp)) 736 return -EIO; 737 return put_user(tmp, (unsigned long __user *)data); 738 } 739 740 int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) 741 { 742 int copied; 743 744 copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 745 return (copied == sizeof(data)) ? 0 : -EIO; 746 } 747 748 #if defined CONFIG_COMPAT 749 #include <linux/compat.h> 750 751 int compat_ptrace_request(struct task_struct *child, compat_long_t request, 752 compat_ulong_t addr, compat_ulong_t data) 753 { 754 compat_ulong_t __user *datap = compat_ptr(data); 755 compat_ulong_t word; 756 siginfo_t siginfo; 757 int ret; 758 759 switch (request) { 760 case PTRACE_PEEKTEXT: 761 case PTRACE_PEEKDATA: 762 ret = access_process_vm(child, addr, &word, sizeof(word), 0); 763 if (ret != sizeof(word)) 764 ret = -EIO; 765 else 766 ret = put_user(word, datap); 767 break; 768 769 case PTRACE_POKETEXT: 770 case PTRACE_POKEDATA: 771 ret = access_process_vm(child, addr, &data, sizeof(data), 1); 772 ret = (ret != sizeof(data) ? -EIO : 0); 773 break; 774 775 case PTRACE_GETEVENTMSG: 776 ret = put_user((compat_ulong_t) child->ptrace_message, datap); 777 break; 778 779 case PTRACE_GETSIGINFO: 780 ret = ptrace_getsiginfo(child, &siginfo); 781 if (!ret) 782 ret = copy_siginfo_to_user32( 783 (struct compat_siginfo __user *) datap, 784 &siginfo); 785 break; 786 787 case PTRACE_SETSIGINFO: 788 memset(&siginfo, 0, sizeof siginfo); 789 if (copy_siginfo_from_user32( 790 &siginfo, (struct compat_siginfo __user *) datap)) 791 ret = -EFAULT; 792 else 793 ret = ptrace_setsiginfo(child, &siginfo); 794 break; 795 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 796 case PTRACE_GETREGSET: 797 case PTRACE_SETREGSET: 798 { 799 struct iovec kiov; 800 struct compat_iovec __user *uiov = 801 (struct compat_iovec __user *) datap; 802 compat_uptr_t ptr; 803 compat_size_t len; 804 805 if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 806 return -EFAULT; 807 808 if (__get_user(ptr, &uiov->iov_base) || 809 __get_user(len, &uiov->iov_len)) 810 return -EFAULT; 811 812 kiov.iov_base = compat_ptr(ptr); 813 kiov.iov_len = len; 814 815 ret = ptrace_regset(child, request, addr, &kiov); 816 if (!ret) 817 ret = __put_user(kiov.iov_len, &uiov->iov_len); 818 break; 819 } 820 #endif 821 822 default: 823 ret = ptrace_request(child, request, addr, data); 824 } 825 826 return ret; 827 } 828 829 asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 830 compat_long_t addr, compat_long_t data) 831 { 832 struct task_struct *child; 833 long ret; 834 835 if (request == PTRACE_TRACEME) { 836 ret = ptrace_traceme(); 837 goto out; 838 } 839 840 child = ptrace_get_task_struct(pid); 841 if (IS_ERR(child)) { 842 ret = PTR_ERR(child); 843 goto out; 844 } 845 846 if (request == PTRACE_ATTACH) { 847 ret = ptrace_attach(child); 848 /* 849 * Some architectures need to do book-keeping after 850 * a ptrace attach. 851 */ 852 if (!ret) 853 arch_ptrace_attach(child); 854 goto out_put_task_struct; 855 } 856 857 ret = ptrace_check_attach(child, request == PTRACE_KILL); 858 if (!ret) 859 ret = compat_arch_ptrace(child, request, addr, data); 860 861 out_put_task_struct: 862 put_task_struct(child); 863 out: 864 return ret; 865 } 866 #endif /* CONFIG_COMPAT */ 867