1 /*- 2 * Copyright (c) 1994, Sean Eric Fagan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Sean Eric Fagan. 16 * 4. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_compat.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/syscallsubr.h> 42 #include <sys/sysent.h> 43 #include <sys/sysproto.h> 44 #include <sys/proc.h> 45 #include <sys/vnode.h> 46 #include <sys/ptrace.h> 47 #include <sys/sx.h> 48 #include <sys/malloc.h> 49 #include <sys/signalvar.h> 50 51 #include <machine/reg.h> 52 53 #include <security/audit/audit.h> 54 55 #include <vm/vm.h> 56 #include <vm/pmap.h> 57 #include <vm/vm_extern.h> 58 #include <vm/vm_map.h> 59 #include <vm/vm_kern.h> 60 #include <vm/vm_object.h> 61 #include <vm/vm_page.h> 62 #include <vm/vm_pager.h> 63 #include <vm/vm_param.h> 64 65 #ifdef COMPAT_FREEBSD32 66 #include <sys/procfs.h> 67 #include <compat/freebsd32/freebsd32_signal.h> 68 69 struct ptrace_io_desc32 { 70 int piod_op; 71 uint32_t piod_offs; 72 uint32_t piod_addr; 73 uint32_t piod_len; 74 }; 75 76 struct ptrace_vm_entry32 { 77 int pve_entry; 78 int pve_timestamp; 79 uint32_t pve_start; 80 uint32_t pve_end; 81 uint32_t pve_offset; 82 u_int pve_prot; 83 u_int pve_pathlen; 84 int32_t pve_fileid; 85 u_int pve_fsid; 86 uint32_t pve_path; 87 }; 88 89 struct ptrace_lwpinfo32 { 90 lwpid_t pl_lwpid; /* LWP described. */ 91 int pl_event; /* Event that stopped the LWP. */ 92 int pl_flags; /* LWP flags. */ 93 sigset_t pl_sigmask; /* LWP signal mask */ 94 sigset_t pl_siglist; /* LWP pending signal */ 95 struct siginfo32 pl_siginfo; /* siginfo for signal */ 96 }; 97 98 #endif 99 100 /* 101 * Functions implemented using PROC_ACTION(): 102 * 103 * proc_read_regs(proc, regs) 104 * Get the current user-visible register set from the process 105 * and copy it into the regs structure (<machine/reg.h>). 106 * The process is stopped at the time read_regs is called. 107 * 108 * proc_write_regs(proc, regs) 109 * Update the current register set from the passed in regs 110 * structure. Take care to avoid clobbering special CPU 111 * registers or privileged bits in the PSL. 112 * Depending on the architecture this may have fix-up work to do, 113 * especially if the IAR or PCW are modified. 114 * The process is stopped at the time write_regs is called. 115 * 116 * proc_read_fpregs, proc_write_fpregs 117 * deal with the floating point register set, otherwise as above. 118 * 119 * proc_read_dbregs, proc_write_dbregs 120 * deal with the processor debug register set, otherwise as above. 121 * 122 * proc_sstep(proc) 123 * Arrange for the process to trap after executing a single instruction. 124 */ 125 126 #define PROC_ACTION(action) do { \ 127 int error; \ 128 \ 129 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); \ 130 if ((td->td_proc->p_flag & P_INMEM) == 0) \ 131 error = EIO; \ 132 else \ 133 error = (action); \ 134 return (error); \ 135 } while(0) 136 137 int 138 proc_read_regs(struct thread *td, struct reg *regs) 139 { 140 141 PROC_ACTION(fill_regs(td, regs)); 142 } 143 144 int 145 proc_write_regs(struct thread *td, struct reg *regs) 146 { 147 148 PROC_ACTION(set_regs(td, regs)); 149 } 150 151 int 152 proc_read_dbregs(struct thread *td, struct dbreg *dbregs) 153 { 154 155 PROC_ACTION(fill_dbregs(td, dbregs)); 156 } 157 158 int 159 proc_write_dbregs(struct thread *td, struct dbreg *dbregs) 160 { 161 162 PROC_ACTION(set_dbregs(td, dbregs)); 163 } 164 165 /* 166 * Ptrace doesn't support fpregs at all, and there are no security holes 167 * or translations for fpregs, so we can just copy them. 168 */ 169 int 170 proc_read_fpregs(struct thread *td, struct fpreg *fpregs) 171 { 172 173 PROC_ACTION(fill_fpregs(td, fpregs)); 174 } 175 176 int 177 proc_write_fpregs(struct thread *td, struct fpreg *fpregs) 178 { 179 180 PROC_ACTION(set_fpregs(td, fpregs)); 181 } 182 183 #ifdef COMPAT_FREEBSD32 184 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */ 185 int 186 proc_read_regs32(struct thread *td, struct reg32 *regs32) 187 { 188 189 PROC_ACTION(fill_regs32(td, regs32)); 190 } 191 192 int 193 proc_write_regs32(struct thread *td, struct reg32 *regs32) 194 { 195 196 PROC_ACTION(set_regs32(td, regs32)); 197 } 198 199 int 200 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 201 { 202 203 PROC_ACTION(fill_dbregs32(td, dbregs32)); 204 } 205 206 int 207 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 208 { 209 210 PROC_ACTION(set_dbregs32(td, dbregs32)); 211 } 212 213 int 214 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 215 { 216 217 PROC_ACTION(fill_fpregs32(td, fpregs32)); 218 } 219 220 int 221 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 222 { 223 224 PROC_ACTION(set_fpregs32(td, fpregs32)); 225 } 226 #endif 227 228 int 229 proc_sstep(struct thread *td) 230 { 231 232 PROC_ACTION(ptrace_single_step(td)); 233 } 234 235 int 236 proc_rwmem(struct proc *p, struct uio *uio) 237 { 238 vm_map_t map; 239 vm_object_t backing_object, object; 240 vm_offset_t pageno; /* page number */ 241 vm_prot_t reqprot; 242 int error, writing; 243 244 /* 245 * Assert that someone has locked this vmspace. (Should be 246 * curthread but we can't assert that.) This keeps the process 247 * from exiting out from under us until this operation completes. 248 */ 249 KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__, 250 p, p->p_pid)); 251 252 /* 253 * The map we want... 254 */ 255 map = &p->p_vmspace->vm_map; 256 257 writing = uio->uio_rw == UIO_WRITE; 258 reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ; 259 260 /* 261 * Only map in one page at a time. We don't have to, but it 262 * makes things easier. This way is trivial - right? 263 */ 264 do { 265 vm_map_t tmap; 266 vm_offset_t uva; 267 int page_offset; /* offset into page */ 268 vm_map_entry_t out_entry; 269 vm_prot_t out_prot; 270 boolean_t wired; 271 vm_pindex_t pindex; 272 u_int len; 273 vm_page_t m; 274 275 object = NULL; 276 277 uva = (vm_offset_t)uio->uio_offset; 278 279 /* 280 * Get the page number of this segment. 281 */ 282 pageno = trunc_page(uva); 283 page_offset = uva - pageno; 284 285 /* 286 * How many bytes to copy 287 */ 288 len = min(PAGE_SIZE - page_offset, uio->uio_resid); 289 290 /* 291 * Fault the page on behalf of the process 292 */ 293 error = vm_fault(map, pageno, reqprot, VM_FAULT_NORMAL); 294 if (error) { 295 if (error == KERN_RESOURCE_SHORTAGE) 296 error = ENOMEM; 297 else 298 error = EFAULT; 299 break; 300 } 301 302 /* 303 * Now we need to get the page. out_entry and wired 304 * aren't used. One would think the vm code 305 * would be a *bit* nicer... We use tmap because 306 * vm_map_lookup() can change the map argument. 307 */ 308 tmap = map; 309 error = vm_map_lookup(&tmap, pageno, reqprot, &out_entry, 310 &object, &pindex, &out_prot, &wired); 311 if (error) { 312 error = EFAULT; 313 break; 314 } 315 VM_OBJECT_LOCK(object); 316 while ((m = vm_page_lookup(object, pindex)) == NULL && 317 !writing && 318 (backing_object = object->backing_object) != NULL) { 319 /* 320 * Allow fallback to backing objects if we are reading. 321 */ 322 VM_OBJECT_LOCK(backing_object); 323 pindex += OFF_TO_IDX(object->backing_object_offset); 324 VM_OBJECT_UNLOCK(object); 325 object = backing_object; 326 } 327 if (writing && m != NULL) { 328 vm_page_dirty(m); 329 vm_pager_page_unswapped(m); 330 } 331 VM_OBJECT_UNLOCK(object); 332 if (m == NULL) { 333 vm_map_lookup_done(tmap, out_entry); 334 error = EFAULT; 335 break; 336 } 337 338 /* 339 * Hold the page in memory. 340 */ 341 vm_page_lock(m); 342 vm_page_hold(m); 343 vm_page_unlock(m); 344 345 /* 346 * We're done with tmap now. 347 */ 348 vm_map_lookup_done(tmap, out_entry); 349 350 /* 351 * Now do the i/o move. 352 */ 353 error = uiomove_fromphys(&m, page_offset, len, uio); 354 355 /* Make the I-cache coherent for breakpoints. */ 356 if (!error && writing && (out_prot & VM_PROT_EXECUTE)) 357 vm_sync_icache(map, uva, len); 358 359 /* 360 * Release the page. 361 */ 362 vm_page_lock(m); 363 vm_page_unhold(m); 364 vm_page_unlock(m); 365 366 } while (error == 0 && uio->uio_resid > 0); 367 368 return (error); 369 } 370 371 static int 372 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve) 373 { 374 struct vattr vattr; 375 vm_map_t map; 376 vm_map_entry_t entry; 377 vm_object_t obj, tobj, lobj; 378 struct vmspace *vm; 379 struct vnode *vp; 380 char *freepath, *fullpath; 381 u_int pathlen; 382 int error, index, vfslocked; 383 384 error = 0; 385 obj = NULL; 386 387 vm = vmspace_acquire_ref(p); 388 map = &vm->vm_map; 389 vm_map_lock_read(map); 390 391 do { 392 entry = map->header.next; 393 index = 0; 394 while (index < pve->pve_entry && entry != &map->header) { 395 entry = entry->next; 396 index++; 397 } 398 if (index != pve->pve_entry) { 399 error = EINVAL; 400 break; 401 } 402 while (entry != &map->header && 403 (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 404 entry = entry->next; 405 index++; 406 } 407 if (entry == &map->header) { 408 error = ENOENT; 409 break; 410 } 411 412 /* We got an entry. */ 413 pve->pve_entry = index + 1; 414 pve->pve_timestamp = map->timestamp; 415 pve->pve_start = entry->start; 416 pve->pve_end = entry->end - 1; 417 pve->pve_offset = entry->offset; 418 pve->pve_prot = entry->protection; 419 420 /* Backing object's path needed? */ 421 if (pve->pve_pathlen == 0) 422 break; 423 424 pathlen = pve->pve_pathlen; 425 pve->pve_pathlen = 0; 426 427 obj = entry->object.vm_object; 428 if (obj != NULL) 429 VM_OBJECT_LOCK(obj); 430 } while (0); 431 432 vm_map_unlock_read(map); 433 vmspace_free(vm); 434 435 pve->pve_fsid = VNOVAL; 436 pve->pve_fileid = VNOVAL; 437 438 if (error == 0 && obj != NULL) { 439 lobj = obj; 440 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 441 if (tobj != obj) 442 VM_OBJECT_LOCK(tobj); 443 if (lobj != obj) 444 VM_OBJECT_UNLOCK(lobj); 445 lobj = tobj; 446 pve->pve_offset += tobj->backing_object_offset; 447 } 448 vp = (lobj->type == OBJT_VNODE) ? lobj->handle : NULL; 449 if (vp != NULL) 450 vref(vp); 451 if (lobj != obj) 452 VM_OBJECT_UNLOCK(lobj); 453 VM_OBJECT_UNLOCK(obj); 454 455 if (vp != NULL) { 456 freepath = NULL; 457 fullpath = NULL; 458 vn_fullpath(td, vp, &fullpath, &freepath); 459 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 460 vn_lock(vp, LK_SHARED | LK_RETRY); 461 if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) { 462 pve->pve_fileid = vattr.va_fileid; 463 pve->pve_fsid = vattr.va_fsid; 464 } 465 vput(vp); 466 VFS_UNLOCK_GIANT(vfslocked); 467 468 if (fullpath != NULL) { 469 pve->pve_pathlen = strlen(fullpath) + 1; 470 if (pve->pve_pathlen <= pathlen) { 471 error = copyout(fullpath, pve->pve_path, 472 pve->pve_pathlen); 473 } else 474 error = ENAMETOOLONG; 475 } 476 if (freepath != NULL) 477 free(freepath, M_TEMP); 478 } 479 } 480 481 return (error); 482 } 483 484 #ifdef COMPAT_FREEBSD32 485 static int 486 ptrace_vm_entry32(struct thread *td, struct proc *p, 487 struct ptrace_vm_entry32 *pve32) 488 { 489 struct ptrace_vm_entry pve; 490 int error; 491 492 pve.pve_entry = pve32->pve_entry; 493 pve.pve_pathlen = pve32->pve_pathlen; 494 pve.pve_path = (void *)(uintptr_t)pve32->pve_path; 495 496 error = ptrace_vm_entry(td, p, &pve); 497 if (error == 0) { 498 pve32->pve_entry = pve.pve_entry; 499 pve32->pve_timestamp = pve.pve_timestamp; 500 pve32->pve_start = pve.pve_start; 501 pve32->pve_end = pve.pve_end; 502 pve32->pve_offset = pve.pve_offset; 503 pve32->pve_prot = pve.pve_prot; 504 pve32->pve_fileid = pve.pve_fileid; 505 pve32->pve_fsid = pve.pve_fsid; 506 } 507 508 pve32->pve_pathlen = pve.pve_pathlen; 509 return (error); 510 } 511 512 static void 513 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl, 514 struct ptrace_lwpinfo32 *pl32) 515 { 516 517 pl32->pl_lwpid = pl->pl_lwpid; 518 pl32->pl_event = pl->pl_event; 519 pl32->pl_flags = pl->pl_flags; 520 pl32->pl_sigmask = pl->pl_sigmask; 521 pl32->pl_siglist = pl->pl_siglist; 522 siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo); 523 } 524 #endif /* COMPAT_FREEBSD32 */ 525 526 /* 527 * Process debugging system call. 528 */ 529 #ifndef _SYS_SYSPROTO_H_ 530 struct ptrace_args { 531 int req; 532 pid_t pid; 533 caddr_t addr; 534 int data; 535 }; 536 #endif 537 538 #ifdef COMPAT_FREEBSD32 539 /* 540 * This CPP subterfuge is to try and reduce the number of ifdefs in 541 * the body of the code. 542 * COPYIN(uap->addr, &r.reg, sizeof r.reg); 543 * becomes either: 544 * copyin(uap->addr, &r.reg, sizeof r.reg); 545 * or 546 * copyin(uap->addr, &r.reg32, sizeof r.reg32); 547 * .. except this is done at runtime. 548 */ 549 #define COPYIN(u, k, s) wrap32 ? \ 550 copyin(u, k ## 32, s ## 32) : \ 551 copyin(u, k, s) 552 #define COPYOUT(k, u, s) wrap32 ? \ 553 copyout(k ## 32, u, s ## 32) : \ 554 copyout(k, u, s) 555 #else 556 #define COPYIN(u, k, s) copyin(u, k, s) 557 #define COPYOUT(k, u, s) copyout(k, u, s) 558 #endif 559 int 560 ptrace(struct thread *td, struct ptrace_args *uap) 561 { 562 /* 563 * XXX this obfuscation is to reduce stack usage, but the register 564 * structs may be too large to put on the stack anyway. 565 */ 566 union { 567 struct ptrace_io_desc piod; 568 struct ptrace_lwpinfo pl; 569 struct ptrace_vm_entry pve; 570 struct dbreg dbreg; 571 struct fpreg fpreg; 572 struct reg reg; 573 #ifdef COMPAT_FREEBSD32 574 struct dbreg32 dbreg32; 575 struct fpreg32 fpreg32; 576 struct reg32 reg32; 577 struct ptrace_io_desc32 piod32; 578 struct ptrace_lwpinfo32 pl32; 579 struct ptrace_vm_entry32 pve32; 580 #endif 581 } r; 582 void *addr; 583 int error = 0; 584 #ifdef COMPAT_FREEBSD32 585 int wrap32 = 0; 586 587 if (SV_CURPROC_FLAG(SV_ILP32)) 588 wrap32 = 1; 589 #endif 590 AUDIT_ARG_PID(uap->pid); 591 AUDIT_ARG_CMD(uap->req); 592 AUDIT_ARG_VALUE(uap->data); 593 addr = &r; 594 switch (uap->req) { 595 case PT_GETREGS: 596 case PT_GETFPREGS: 597 case PT_GETDBREGS: 598 case PT_LWPINFO: 599 break; 600 case PT_SETREGS: 601 error = COPYIN(uap->addr, &r.reg, sizeof r.reg); 602 break; 603 case PT_SETFPREGS: 604 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg); 605 break; 606 case PT_SETDBREGS: 607 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg); 608 break; 609 case PT_IO: 610 error = COPYIN(uap->addr, &r.piod, sizeof r.piod); 611 break; 612 case PT_VM_ENTRY: 613 error = COPYIN(uap->addr, &r.pve, sizeof r.pve); 614 break; 615 default: 616 addr = uap->addr; 617 break; 618 } 619 if (error) 620 return (error); 621 622 error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data); 623 if (error) 624 return (error); 625 626 switch (uap->req) { 627 case PT_VM_ENTRY: 628 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve); 629 break; 630 case PT_IO: 631 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod); 632 break; 633 case PT_GETREGS: 634 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg); 635 break; 636 case PT_GETFPREGS: 637 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg); 638 break; 639 case PT_GETDBREGS: 640 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg); 641 break; 642 case PT_LWPINFO: 643 error = copyout(&r.pl, uap->addr, uap->data); 644 break; 645 } 646 647 return (error); 648 } 649 #undef COPYIN 650 #undef COPYOUT 651 652 #ifdef COMPAT_FREEBSD32 653 /* 654 * PROC_READ(regs, td2, addr); 655 * becomes either: 656 * proc_read_regs(td2, addr); 657 * or 658 * proc_read_regs32(td2, addr); 659 * .. except this is done at runtime. There is an additional 660 * complication in that PROC_WRITE disallows 32 bit consumers 661 * from writing to 64 bit address space targets. 662 */ 663 #define PROC_READ(w, t, a) wrap32 ? \ 664 proc_read_ ## w ## 32(t, a) : \ 665 proc_read_ ## w (t, a) 666 #define PROC_WRITE(w, t, a) wrap32 ? \ 667 (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \ 668 proc_write_ ## w (t, a) 669 #else 670 #define PROC_READ(w, t, a) proc_read_ ## w (t, a) 671 #define PROC_WRITE(w, t, a) proc_write_ ## w (t, a) 672 #endif 673 674 int 675 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) 676 { 677 struct iovec iov; 678 struct uio uio; 679 struct proc *curp, *p, *pp; 680 struct thread *td2 = NULL; 681 struct ptrace_io_desc *piod = NULL; 682 struct ptrace_lwpinfo *pl; 683 int error, write, tmp, num; 684 int proctree_locked = 0; 685 lwpid_t tid = 0, *buf; 686 #ifdef COMPAT_FREEBSD32 687 int wrap32 = 0, safe = 0; 688 struct ptrace_io_desc32 *piod32 = NULL; 689 struct ptrace_lwpinfo32 *pl32 = NULL; 690 struct ptrace_lwpinfo plr; 691 #endif 692 693 curp = td->td_proc; 694 695 /* Lock proctree before locking the process. */ 696 switch (req) { 697 case PT_TRACE_ME: 698 case PT_ATTACH: 699 case PT_STEP: 700 case PT_CONTINUE: 701 case PT_TO_SCE: 702 case PT_TO_SCX: 703 case PT_SYSCALL: 704 case PT_DETACH: 705 sx_xlock(&proctree_lock); 706 proctree_locked = 1; 707 break; 708 default: 709 break; 710 } 711 712 write = 0; 713 if (req == PT_TRACE_ME) { 714 p = td->td_proc; 715 PROC_LOCK(p); 716 } else { 717 if (pid <= PID_MAX) { 718 if ((p = pfind(pid)) == NULL) { 719 if (proctree_locked) 720 sx_xunlock(&proctree_lock); 721 return (ESRCH); 722 } 723 } else { 724 td2 = tdfind(pid, -1); 725 if (td2 == NULL) { 726 if (proctree_locked) 727 sx_xunlock(&proctree_lock); 728 return (ESRCH); 729 } 730 p = td2->td_proc; 731 tid = pid; 732 pid = p->p_pid; 733 } 734 } 735 AUDIT_ARG_PROCESS(p); 736 737 if ((p->p_flag & P_WEXIT) != 0) { 738 error = ESRCH; 739 goto fail; 740 } 741 if ((error = p_cansee(td, p)) != 0) 742 goto fail; 743 744 if ((error = p_candebug(td, p)) != 0) 745 goto fail; 746 747 /* 748 * System processes can't be debugged. 749 */ 750 if ((p->p_flag & P_SYSTEM) != 0) { 751 error = EINVAL; 752 goto fail; 753 } 754 755 if (tid == 0) { 756 if ((p->p_flag & P_STOPPED_TRACE) != 0) { 757 KASSERT(p->p_xthread != NULL, ("NULL p_xthread")); 758 td2 = p->p_xthread; 759 } else { 760 td2 = FIRST_THREAD_IN_PROC(p); 761 } 762 tid = td2->td_tid; 763 } 764 765 #ifdef COMPAT_FREEBSD32 766 /* 767 * Test if we're a 32 bit client and what the target is. 768 * Set the wrap controls accordingly. 769 */ 770 if (SV_CURPROC_FLAG(SV_ILP32)) { 771 if (td2->td_proc->p_sysent->sv_flags & SV_ILP32) 772 safe = 1; 773 wrap32 = 1; 774 } 775 #endif 776 /* 777 * Permissions check 778 */ 779 switch (req) { 780 case PT_TRACE_ME: 781 /* Always legal. */ 782 break; 783 784 case PT_ATTACH: 785 /* Self */ 786 if (p->p_pid == td->td_proc->p_pid) { 787 error = EINVAL; 788 goto fail; 789 } 790 791 /* Already traced */ 792 if (p->p_flag & P_TRACED) { 793 error = EBUSY; 794 goto fail; 795 } 796 797 /* Can't trace an ancestor if you're being traced. */ 798 if (curp->p_flag & P_TRACED) { 799 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) { 800 if (pp == p) { 801 error = EINVAL; 802 goto fail; 803 } 804 } 805 } 806 807 808 /* OK */ 809 break; 810 811 case PT_CLEARSTEP: 812 /* Allow thread to clear single step for itself */ 813 if (td->td_tid == tid) 814 break; 815 816 /* FALLTHROUGH */ 817 default: 818 /* not being traced... */ 819 if ((p->p_flag & P_TRACED) == 0) { 820 error = EPERM; 821 goto fail; 822 } 823 824 /* not being traced by YOU */ 825 if (p->p_pptr != td->td_proc) { 826 error = EBUSY; 827 goto fail; 828 } 829 830 /* not currently stopped */ 831 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 || 832 p->p_suspcount != p->p_numthreads || 833 (p->p_flag & P_WAITED) == 0) { 834 error = EBUSY; 835 goto fail; 836 } 837 838 if ((p->p_flag & P_STOPPED_TRACE) == 0) { 839 static int count = 0; 840 if (count++ == 0) 841 printf("P_STOPPED_TRACE not set.\n"); 842 } 843 844 /* OK */ 845 break; 846 } 847 848 /* Keep this process around until we finish this request. */ 849 _PHOLD(p); 850 851 #ifdef FIX_SSTEP 852 /* 853 * Single step fixup ala procfs 854 */ 855 FIX_SSTEP(td2); 856 #endif 857 858 /* 859 * Actually do the requests 860 */ 861 862 td->td_retval[0] = 0; 863 864 switch (req) { 865 case PT_TRACE_ME: 866 /* set my trace flag and "owner" so it can read/write me */ 867 p->p_flag |= P_TRACED; 868 p->p_oppid = p->p_pptr->p_pid; 869 break; 870 871 case PT_ATTACH: 872 /* security check done above */ 873 p->p_flag |= P_TRACED; 874 p->p_oppid = p->p_pptr->p_pid; 875 if (p->p_pptr != td->td_proc) 876 proc_reparent(p, td->td_proc); 877 data = SIGSTOP; 878 goto sendsig; /* in PT_CONTINUE below */ 879 880 case PT_CLEARSTEP: 881 error = ptrace_clear_single_step(td2); 882 break; 883 884 case PT_SETSTEP: 885 error = ptrace_single_step(td2); 886 break; 887 888 case PT_SUSPEND: 889 td2->td_dbgflags |= TDB_SUSPEND; 890 thread_lock(td2); 891 td2->td_flags |= TDF_NEEDSUSPCHK; 892 thread_unlock(td2); 893 break; 894 895 case PT_RESUME: 896 td2->td_dbgflags &= ~TDB_SUSPEND; 897 break; 898 899 case PT_STEP: 900 case PT_CONTINUE: 901 case PT_TO_SCE: 902 case PT_TO_SCX: 903 case PT_SYSCALL: 904 case PT_DETACH: 905 /* Zero means do not send any signal */ 906 if (data < 0 || data > _SIG_MAXSIG) { 907 error = EINVAL; 908 break; 909 } 910 911 switch (req) { 912 case PT_STEP: 913 error = ptrace_single_step(td2); 914 if (error) 915 goto out; 916 break; 917 case PT_CONTINUE: 918 case PT_TO_SCE: 919 case PT_TO_SCX: 920 case PT_SYSCALL: 921 if (addr != (void *)1) { 922 error = ptrace_set_pc(td2, 923 (u_long)(uintfptr_t)addr); 924 if (error) 925 goto out; 926 } 927 switch (req) { 928 case PT_TO_SCE: 929 p->p_stops |= S_PT_SCE; 930 break; 931 case PT_TO_SCX: 932 p->p_stops |= S_PT_SCX; 933 break; 934 case PT_SYSCALL: 935 p->p_stops |= S_PT_SCE | S_PT_SCX; 936 break; 937 } 938 break; 939 case PT_DETACH: 940 /* reset process parent */ 941 if (p->p_oppid != p->p_pptr->p_pid) { 942 struct proc *pp; 943 944 PROC_LOCK(p->p_pptr); 945 sigqueue_take(p->p_ksi); 946 PROC_UNLOCK(p->p_pptr); 947 948 PROC_UNLOCK(p); 949 pp = pfind(p->p_oppid); 950 if (pp == NULL) 951 pp = initproc; 952 else 953 PROC_UNLOCK(pp); 954 PROC_LOCK(p); 955 proc_reparent(p, pp); 956 if (pp == initproc) 957 p->p_sigparent = SIGCHLD; 958 } 959 p->p_flag &= ~(P_TRACED | P_WAITED); 960 p->p_oppid = 0; 961 962 /* should we send SIGCHLD? */ 963 /* childproc_continued(p); */ 964 break; 965 } 966 967 sendsig: 968 if (proctree_locked) { 969 sx_xunlock(&proctree_lock); 970 proctree_locked = 0; 971 } 972 p->p_xstat = data; 973 p->p_xthread = NULL; 974 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) { 975 /* deliver or queue signal */ 976 td2->td_dbgflags &= ~TDB_XSIG; 977 td2->td_xsig = data; 978 979 if (req == PT_DETACH) { 980 struct thread *td3; 981 FOREACH_THREAD_IN_PROC(p, td3) { 982 td3->td_dbgflags &= ~TDB_SUSPEND; 983 } 984 } 985 /* 986 * unsuspend all threads, to not let a thread run, 987 * you should use PT_SUSPEND to suspend it before 988 * continuing process. 989 */ 990 PROC_SLOCK(p); 991 p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED); 992 thread_unsuspend(p); 993 PROC_SUNLOCK(p); 994 } else { 995 if (data) 996 psignal(p, data); 997 } 998 break; 999 1000 case PT_WRITE_I: 1001 case PT_WRITE_D: 1002 td2->td_dbgflags |= TDB_USERWR; 1003 write = 1; 1004 /* FALLTHROUGH */ 1005 case PT_READ_I: 1006 case PT_READ_D: 1007 PROC_UNLOCK(p); 1008 tmp = 0; 1009 /* write = 0 set above */ 1010 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; 1011 iov.iov_len = sizeof(int); 1012 uio.uio_iov = &iov; 1013 uio.uio_iovcnt = 1; 1014 uio.uio_offset = (off_t)(uintptr_t)addr; 1015 uio.uio_resid = sizeof(int); 1016 uio.uio_segflg = UIO_SYSSPACE; /* i.e.: the uap */ 1017 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 1018 uio.uio_td = td; 1019 error = proc_rwmem(p, &uio); 1020 if (uio.uio_resid != 0) { 1021 /* 1022 * XXX proc_rwmem() doesn't currently return ENOSPC, 1023 * so I think write() can bogusly return 0. 1024 * XXX what happens for short writes? We don't want 1025 * to write partial data. 1026 * XXX proc_rwmem() returns EPERM for other invalid 1027 * addresses. Convert this to EINVAL. Does this 1028 * clobber returns of EPERM for other reasons? 1029 */ 1030 if (error == 0 || error == ENOSPC || error == EPERM) 1031 error = EINVAL; /* EOF */ 1032 } 1033 if (!write) 1034 td->td_retval[0] = tmp; 1035 PROC_LOCK(p); 1036 break; 1037 1038 case PT_IO: 1039 #ifdef COMPAT_FREEBSD32 1040 if (wrap32) { 1041 piod32 = addr; 1042 iov.iov_base = (void *)(uintptr_t)piod32->piod_addr; 1043 iov.iov_len = piod32->piod_len; 1044 uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs; 1045 uio.uio_resid = piod32->piod_len; 1046 } else 1047 #endif 1048 { 1049 piod = addr; 1050 iov.iov_base = piod->piod_addr; 1051 iov.iov_len = piod->piod_len; 1052 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; 1053 uio.uio_resid = piod->piod_len; 1054 } 1055 uio.uio_iov = &iov; 1056 uio.uio_iovcnt = 1; 1057 uio.uio_segflg = UIO_USERSPACE; 1058 uio.uio_td = td; 1059 #ifdef COMPAT_FREEBSD32 1060 tmp = wrap32 ? piod32->piod_op : piod->piod_op; 1061 #else 1062 tmp = piod->piod_op; 1063 #endif 1064 switch (tmp) { 1065 case PIOD_READ_D: 1066 case PIOD_READ_I: 1067 uio.uio_rw = UIO_READ; 1068 break; 1069 case PIOD_WRITE_D: 1070 case PIOD_WRITE_I: 1071 td2->td_dbgflags |= TDB_USERWR; 1072 uio.uio_rw = UIO_WRITE; 1073 break; 1074 default: 1075 error = EINVAL; 1076 goto out; 1077 } 1078 PROC_UNLOCK(p); 1079 error = proc_rwmem(p, &uio); 1080 #ifdef COMPAT_FREEBSD32 1081 if (wrap32) 1082 piod32->piod_len -= uio.uio_resid; 1083 else 1084 #endif 1085 piod->piod_len -= uio.uio_resid; 1086 PROC_LOCK(p); 1087 break; 1088 1089 case PT_KILL: 1090 data = SIGKILL; 1091 goto sendsig; /* in PT_CONTINUE above */ 1092 1093 case PT_SETREGS: 1094 td2->td_dbgflags |= TDB_USERWR; 1095 error = PROC_WRITE(regs, td2, addr); 1096 break; 1097 1098 case PT_GETREGS: 1099 error = PROC_READ(regs, td2, addr); 1100 break; 1101 1102 case PT_SETFPREGS: 1103 td2->td_dbgflags |= TDB_USERWR; 1104 error = PROC_WRITE(fpregs, td2, addr); 1105 break; 1106 1107 case PT_GETFPREGS: 1108 error = PROC_READ(fpregs, td2, addr); 1109 break; 1110 1111 case PT_SETDBREGS: 1112 td2->td_dbgflags |= TDB_USERWR; 1113 error = PROC_WRITE(dbregs, td2, addr); 1114 break; 1115 1116 case PT_GETDBREGS: 1117 error = PROC_READ(dbregs, td2, addr); 1118 break; 1119 1120 case PT_LWPINFO: 1121 if (data <= 0 || 1122 #ifdef COMPAT_FREEBSD32 1123 (!wrap32 && data > sizeof(*pl)) || 1124 (wrap32 && data > sizeof(*pl32))) { 1125 #else 1126 data > sizeof(*pl)) { 1127 #endif 1128 error = EINVAL; 1129 break; 1130 } 1131 #ifdef COMPAT_FREEBSD32 1132 if (wrap32) { 1133 pl = &plr; 1134 pl32 = addr; 1135 } else 1136 #endif 1137 pl = addr; 1138 pl->pl_lwpid = td2->td_tid; 1139 pl->pl_flags = 0; 1140 if (td2->td_dbgflags & TDB_XSIG) { 1141 pl->pl_event = PL_EVENT_SIGNAL; 1142 if (td2->td_dbgksi.ksi_signo != 0 && 1143 #ifdef COMPAT_FREEBSD32 1144 ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo, 1145 pl_siginfo) + sizeof(pl->pl_siginfo)) || 1146 (wrap32 && data >= offsetof(struct ptrace_lwpinfo32, 1147 pl_siginfo) + sizeof(struct siginfo32))) 1148 #else 1149 data >= offsetof(struct ptrace_lwpinfo, pl_siginfo) 1150 + sizeof(pl->pl_siginfo) 1151 #endif 1152 ){ 1153 pl->pl_flags |= PL_FLAG_SI; 1154 pl->pl_siginfo = td2->td_dbgksi.ksi_info; 1155 } 1156 } 1157 if ((pl->pl_flags & PL_FLAG_SI) == 0) 1158 bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo)); 1159 if (td2->td_dbgflags & TDB_SCE) 1160 pl->pl_flags |= PL_FLAG_SCE; 1161 else if (td2->td_dbgflags & TDB_SCX) 1162 pl->pl_flags |= PL_FLAG_SCX; 1163 if (td2->td_dbgflags & TDB_EXEC) 1164 pl->pl_flags |= PL_FLAG_EXEC; 1165 pl->pl_sigmask = td2->td_sigmask; 1166 pl->pl_siglist = td2->td_siglist; 1167 #ifdef COMPAT_FREEBSD32 1168 if (wrap32) 1169 ptrace_lwpinfo_to32(pl, pl32); 1170 #endif 1171 break; 1172 1173 case PT_GETNUMLWPS: 1174 td->td_retval[0] = p->p_numthreads; 1175 break; 1176 1177 case PT_GETLWPLIST: 1178 if (data <= 0) { 1179 error = EINVAL; 1180 break; 1181 } 1182 num = imin(p->p_numthreads, data); 1183 PROC_UNLOCK(p); 1184 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK); 1185 tmp = 0; 1186 PROC_LOCK(p); 1187 FOREACH_THREAD_IN_PROC(p, td2) { 1188 if (tmp >= num) 1189 break; 1190 buf[tmp++] = td2->td_tid; 1191 } 1192 PROC_UNLOCK(p); 1193 error = copyout(buf, addr, tmp * sizeof(lwpid_t)); 1194 free(buf, M_TEMP); 1195 if (!error) 1196 td->td_retval[0] = tmp; 1197 PROC_LOCK(p); 1198 break; 1199 1200 case PT_VM_TIMESTAMP: 1201 td->td_retval[0] = p->p_vmspace->vm_map.timestamp; 1202 break; 1203 1204 case PT_VM_ENTRY: 1205 PROC_UNLOCK(p); 1206 #ifdef COMPAT_FREEBSD32 1207 if (wrap32) 1208 error = ptrace_vm_entry32(td, p, addr); 1209 else 1210 #endif 1211 error = ptrace_vm_entry(td, p, addr); 1212 PROC_LOCK(p); 1213 break; 1214 1215 default: 1216 #ifdef __HAVE_PTRACE_MACHDEP 1217 if (req >= PT_FIRSTMACH) { 1218 PROC_UNLOCK(p); 1219 error = cpu_ptrace(td2, req, addr, data); 1220 PROC_LOCK(p); 1221 } else 1222 #endif 1223 /* Unknown request. */ 1224 error = EINVAL; 1225 break; 1226 } 1227 1228 out: 1229 /* Drop our hold on this process now that the request has completed. */ 1230 _PRELE(p); 1231 fail: 1232 PROC_UNLOCK(p); 1233 if (proctree_locked) 1234 sx_xunlock(&proctree_lock); 1235 return (error); 1236 } 1237 #undef PROC_READ 1238 #undef PROC_WRITE 1239 1240 /* 1241 * Stop a process because of a debugging event; 1242 * stay stopped until p->p_step is cleared 1243 * (cleared by PIOCCONT in procfs). 1244 */ 1245 void 1246 stopevent(struct proc *p, unsigned int event, unsigned int val) 1247 { 1248 1249 PROC_LOCK_ASSERT(p, MA_OWNED); 1250 p->p_step = 1; 1251 do { 1252 p->p_xstat = val; 1253 p->p_xthread = NULL; 1254 p->p_stype = event; /* Which event caused the stop? */ 1255 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 1256 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0); 1257 } while (p->p_step); 1258 } 1259