Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/sys_process.c
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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: releng/8.3/sys/kern/sys_process.c 219144 2011-03-01 20:44:14Z dchagin $"); 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_param.h> 63 64 #ifdef COMPAT_FREEBSD32 65 #include <sys/procfs.h> 66 #include <compat/freebsd32/freebsd32_signal.h> 67 68 struct ptrace_io_desc32 { 69 int piod_op; 70 u_int32_t piod_offs; 71 u_int32_t piod_addr; 72 u_int32_t piod_len; 73 }; 74 75 struct ptrace_vm_entry32 { 76 int pve_entry; 77 int pve_timestamp; 78 uint32_t pve_start; 79 uint32_t pve_end; 80 uint32_t pve_offset; 81 u_int pve_prot; 82 u_int pve_pathlen; 83 int32_t pve_fileid; 84 u_int pve_fsid; 85 uint32_t pve_path; 86 }; 87 88 struct ptrace_lwpinfo32 { 89 lwpid_t pl_lwpid; /* LWP described. */ 90 int pl_event; /* Event that stopped the LWP. */ 91 int pl_flags; /* LWP flags. */ 92 sigset_t pl_sigmask; /* LWP signal mask */ 93 sigset_t pl_siglist; /* LWP pending signal */ 94 struct siginfo32 pl_siginfo; /* siginfo for signal */ 95 char pl_tdname[MAXCOMLEN + 1]; /* LWP name. */ 96 int pl_child_pid; /* New child pid */ 97 }; 98 99 #endif 100 101 /* 102 * Functions implemented using PROC_ACTION(): 103 * 104 * proc_read_regs(proc, regs) 105 * Get the current user-visible register set from the process 106 * and copy it into the regs structure (<machine/reg.h>). 107 * The process is stopped at the time read_regs is called. 108 * 109 * proc_write_regs(proc, regs) 110 * Update the current register set from the passed in regs 111 * structure. Take care to avoid clobbering special CPU 112 * registers or privileged bits in the PSL. 113 * Depending on the architecture this may have fix-up work to do, 114 * especially if the IAR or PCW are modified. 115 * The process is stopped at the time write_regs is called. 116 * 117 * proc_read_fpregs, proc_write_fpregs 118 * deal with the floating point register set, otherwise as above. 119 * 120 * proc_read_dbregs, proc_write_dbregs 121 * deal with the processor debug register set, otherwise as above. 122 * 123 * proc_sstep(proc) 124 * Arrange for the process to trap after executing a single instruction. 125 */ 126 127 #define PROC_ACTION(action) do { \ 128 int error; \ 129 \ 130 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); \ 131 if ((td->td_proc->p_flag & P_INMEM) == 0) \ 132 error = EIO; \ 133 else \ 134 error = (action); \ 135 return (error); \ 136 } while(0) 137 138 int 139 proc_read_regs(struct thread *td, struct reg *regs) 140 { 141 142 PROC_ACTION(fill_regs(td, regs)); 143 } 144 145 int 146 proc_write_regs(struct thread *td, struct reg *regs) 147 { 148 149 PROC_ACTION(set_regs(td, regs)); 150 } 151 152 int 153 proc_read_dbregs(struct thread *td, struct dbreg *dbregs) 154 { 155 156 PROC_ACTION(fill_dbregs(td, dbregs)); 157 } 158 159 int 160 proc_write_dbregs(struct thread *td, struct dbreg *dbregs) 161 { 162 163 PROC_ACTION(set_dbregs(td, dbregs)); 164 } 165 166 /* 167 * Ptrace doesn't support fpregs at all, and there are no security holes 168 * or translations for fpregs, so we can just copy them. 169 */ 170 int 171 proc_read_fpregs(struct thread *td, struct fpreg *fpregs) 172 { 173 174 PROC_ACTION(fill_fpregs(td, fpregs)); 175 } 176 177 int 178 proc_write_fpregs(struct thread *td, struct fpreg *fpregs) 179 { 180 181 PROC_ACTION(set_fpregs(td, fpregs)); 182 } 183 184 #ifdef COMPAT_FREEBSD32 185 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */ 186 int 187 proc_read_regs32(struct thread *td, struct reg32 *regs32) 188 { 189 190 PROC_ACTION(fill_regs32(td, regs32)); 191 } 192 193 int 194 proc_write_regs32(struct thread *td, struct reg32 *regs32) 195 { 196 197 PROC_ACTION(set_regs32(td, regs32)); 198 } 199 200 int 201 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 202 { 203 204 PROC_ACTION(fill_dbregs32(td, dbregs32)); 205 } 206 207 int 208 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32) 209 { 210 211 PROC_ACTION(set_dbregs32(td, dbregs32)); 212 } 213 214 int 215 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 216 { 217 218 PROC_ACTION(fill_fpregs32(td, fpregs32)); 219 } 220 221 int 222 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32) 223 { 224 225 PROC_ACTION(set_fpregs32(td, fpregs32)); 226 } 227 #endif 228 229 int 230 proc_sstep(struct thread *td) 231 { 232 233 PROC_ACTION(ptrace_single_step(td)); 234 } 235 236 int 237 proc_rwmem(struct proc *p, struct uio *uio) 238 { 239 vm_map_t map; 240 vm_object_t backing_object, object = NULL; 241 vm_offset_t pageno = 0; /* page number */ 242 vm_prot_t reqprot; 243 int error, fault_flags, writing; 244 245 /* 246 * Assert that someone has locked this vmspace. (Should be 247 * curthread but we can't assert that.) This keeps the process 248 * from exiting out from under us until this operation completes. 249 */ 250 KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__, 251 p, p->p_pid)); 252 253 /* 254 * The map we want... 255 */ 256 map = &p->p_vmspace->vm_map; 257 258 writing = uio->uio_rw == UIO_WRITE; 259 reqprot = writing ? (VM_PROT_WRITE | VM_PROT_OVERRIDE_WRITE) : 260 VM_PROT_READ; 261 fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL; 262 263 /* 264 * Only map in one page at a time. We don't have to, but it 265 * makes things easier. This way is trivial - right? 266 */ 267 do { 268 vm_map_t tmap; 269 vm_offset_t uva; 270 int page_offset; /* offset into page */ 271 vm_map_entry_t out_entry; 272 vm_prot_t out_prot; 273 boolean_t wired; 274 vm_pindex_t pindex; 275 u_int len; 276 vm_page_t m; 277 278 object = NULL; 279 280 uva = (vm_offset_t)uio->uio_offset; 281 282 /* 283 * Get the page number of this segment. 284 */ 285 pageno = trunc_page(uva); 286 page_offset = uva - pageno; 287 288 /* 289 * How many bytes to copy 290 */ 291 len = min(PAGE_SIZE - page_offset, uio->uio_resid); 292 293 /* 294 * Fault the page on behalf of the process 295 */ 296 error = vm_fault(map, pageno, reqprot, fault_flags); 297 if (error) { 298 if (error == KERN_RESOURCE_SHORTAGE) 299 error = ENOMEM; 300 else 301 error = EFAULT; 302 break; 303 } 304 305 /* 306 * Now we need to get the page. out_entry, out_prot, wired, 307 * and single_use aren't used. One would think the vm code 308 * would be a *bit* nicer... We use tmap because 309 * vm_map_lookup() can change the map argument. 310 */ 311 tmap = map; 312 error = vm_map_lookup(&tmap, pageno, reqprot, &out_entry, 313 &object, &pindex, &out_prot, &wired); 314 if (error) { 315 error = EFAULT; 316 break; 317 } 318 VM_OBJECT_LOCK(object); 319 while ((m = vm_page_lookup(object, pindex)) == NULL && 320 !writing && 321 (backing_object = object->backing_object) != NULL) { 322 /* 323 * Allow fallback to backing objects if we are reading. 324 */ 325 VM_OBJECT_LOCK(backing_object); 326 pindex += OFF_TO_IDX(object->backing_object_offset); 327 VM_OBJECT_UNLOCK(object); 328 object = backing_object; 329 } 330 VM_OBJECT_UNLOCK(object); 331 if (m == NULL) { 332 vm_map_lookup_done(tmap, out_entry); 333 error = EFAULT; 334 break; 335 } 336 337 /* 338 * Hold the page in memory. 339 */ 340 vm_page_lock_queues(); 341 vm_page_hold(m); 342 vm_page_unlock_queues(); 343 344 /* 345 * We're done with tmap now. 346 */ 347 vm_map_lookup_done(tmap, out_entry); 348 349 /* 350 * Now do the i/o move. 351 */ 352 error = uiomove_fromphys(&m, page_offset, len, uio); 353 354 /* Make the I-cache coherent for breakpoints. */ 355 if (!error && writing && (out_prot & VM_PROT_EXECUTE)) 356 vm_sync_icache(map, uva, len); 357 358 /* 359 * Release the page. 360 */ 361 vm_page_lock_queues(); 362 vm_page_unhold(m); 363 vm_page_unlock_queues(); 364 365 } while (error == 0 && uio->uio_resid > 0); 366 367 return (error); 368 } 369 370 static int 371 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve) 372 { 373 struct vattr vattr; 374 vm_map_t map; 375 vm_map_entry_t entry; 376 vm_object_t obj, tobj, lobj; 377 struct vmspace *vm; 378 struct vnode *vp; 379 char *freepath, *fullpath; 380 u_int pathlen; 381 int error, index, vfslocked; 382 383 error = 0; 384 obj = NULL; 385 386 vm = vmspace_acquire_ref(p); 387 map = &vm->vm_map; 388 vm_map_lock_read(map); 389 390 do { 391 entry = map->header.next; 392 index = 0; 393 while (index < pve->pve_entry && entry != &map->header) { 394 entry = entry->next; 395 index++; 396 } 397 if (index != pve->pve_entry) { 398 error = EINVAL; 399 break; 400 } 401 while (entry != &map->header && 402 (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 403 entry = entry->next; 404 index++; 405 } 406 if (entry == &map->header) { 407 error = ENOENT; 408 break; 409 } 410 411 /* We got an entry. */ 412 pve->pve_entry = index + 1; 413 pve->pve_timestamp = map->timestamp; 414 pve->pve_start = entry->start; 415 pve->pve_end = entry->end - 1; 416 pve->pve_offset = entry->offset; 417 pve->pve_prot = entry->protection; 418 419 /* Backing object's path needed? */ 420 if (pve->pve_pathlen == 0) 421 break; 422 423 pathlen = pve->pve_pathlen; 424 pve->pve_pathlen = 0; 425 426 obj = entry->object.vm_object; 427 if (obj != NULL) 428 VM_OBJECT_LOCK(obj); 429 } while (0); 430 431 vm_map_unlock_read(map); 432 vmspace_free(vm); 433 434 pve->pve_fsid = VNOVAL; 435 pve->pve_fileid = VNOVAL; 436 437 if (error == 0 && obj != NULL) { 438 lobj = obj; 439 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) { 440 if (tobj != obj) 441 VM_OBJECT_LOCK(tobj); 442 if (lobj != obj) 443 VM_OBJECT_UNLOCK(lobj); 444 lobj = tobj; 445 pve->pve_offset += tobj->backing_object_offset; 446 } 447 vp = (lobj->type == OBJT_VNODE) ? lobj->handle : NULL; 448 if (vp != NULL) 449 vref(vp); 450 if (lobj != obj) 451 VM_OBJECT_UNLOCK(lobj); 452 VM_OBJECT_UNLOCK(obj); 453 454 if (vp != NULL) { 455 freepath = NULL; 456 fullpath = NULL; 457 vn_fullpath(td, vp, &fullpath, &freepath); 458 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 459 vn_lock(vp, LK_SHARED | LK_RETRY); 460 if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) { 461 pve->pve_fileid = vattr.va_fileid; 462 pve->pve_fsid = vattr.va_fsid; 463 } 464 vput(vp); 465 VFS_UNLOCK_GIANT(vfslocked); 466 467 if (fullpath != NULL) { 468 pve->pve_pathlen = strlen(fullpath) + 1; 469 if (pve->pve_pathlen <= pathlen) { 470 error = copyout(fullpath, pve->pve_path, 471 pve->pve_pathlen); 472 } else 473 error = ENAMETOOLONG; 474 } 475 if (freepath != NULL) 476 free(freepath, M_TEMP); 477 } 478 } 479 480 return (error); 481 } 482 483 #ifdef COMPAT_FREEBSD32 484 static int 485 ptrace_vm_entry32(struct thread *td, struct proc *p, 486 struct ptrace_vm_entry32 *pve32) 487 { 488 struct ptrace_vm_entry pve; 489 int error; 490 491 pve.pve_entry = pve32->pve_entry; 492 pve.pve_pathlen = pve32->pve_pathlen; 493 pve.pve_path = (void *)(uintptr_t)pve32->pve_path; 494 495 error = ptrace_vm_entry(td, p, &pve); 496 if (error == 0) { 497 pve32->pve_entry = pve.pve_entry; 498 pve32->pve_timestamp = pve.pve_timestamp; 499 pve32->pve_start = pve.pve_start; 500 pve32->pve_end = pve.pve_end; 501 pve32->pve_offset = pve.pve_offset; 502 pve32->pve_prot = pve.pve_prot; 503 pve32->pve_fileid = pve.pve_fileid; 504 pve32->pve_fsid = pve.pve_fsid; 505 } 506 507 pve32->pve_pathlen = pve.pve_pathlen; 508 return (error); 509 } 510 511 static void 512 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl, 513 struct ptrace_lwpinfo32 *pl32) 514 { 515 516 pl32->pl_lwpid = pl->pl_lwpid; 517 pl32->pl_event = pl->pl_event; 518 pl32->pl_flags = pl->pl_flags; 519 pl32->pl_sigmask = pl->pl_sigmask; 520 pl32->pl_siglist = pl->pl_siglist; 521 siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo); 522 strcpy(pl32->pl_tdname, pl->pl_tdname); 523 pl32->pl_child_pid = pl->pl_child_pid; 524 } 525 #endif /* COMPAT_FREEBSD32 */ 526 527 /* 528 * Process debugging system call. 529 */ 530 #ifndef _SYS_SYSPROTO_H_ 531 struct ptrace_args { 532 int req; 533 pid_t pid; 534 caddr_t addr; 535 int data; 536 }; 537 #endif 538 539 #ifdef COMPAT_FREEBSD32 540 /* 541 * This CPP subterfuge is to try and reduce the number of ifdefs in 542 * the body of the code. 543 * COPYIN(uap->addr, &r.reg, sizeof r.reg); 544 * becomes either: 545 * copyin(uap->addr, &r.reg, sizeof r.reg); 546 * or 547 * copyin(uap->addr, &r.reg32, sizeof r.reg32); 548 * .. except this is done at runtime. 549 */ 550 #define COPYIN(u, k, s) wrap32 ? \ 551 copyin(u, k ## 32, s ## 32) : \ 552 copyin(u, k, s) 553 #define COPYOUT(k, u, s) wrap32 ? \ 554 copyout(k ## 32, u, s ## 32) : \ 555 copyout(k, u, s) 556 #else 557 #define COPYIN(u, k, s) copyin(u, k, s) 558 #define COPYOUT(k, u, s) copyout(k, u, s) 559 #endif 560 int 561 ptrace(struct thread *td, struct ptrace_args *uap) 562 { 563 /* 564 * XXX this obfuscation is to reduce stack usage, but the register 565 * structs may be too large to put on the stack anyway. 566 */ 567 union { 568 struct ptrace_io_desc piod; 569 struct ptrace_lwpinfo pl; 570 struct ptrace_vm_entry pve; 571 struct dbreg dbreg; 572 struct fpreg fpreg; 573 struct reg reg; 574 #ifdef COMPAT_FREEBSD32 575 struct dbreg32 dbreg32; 576 struct fpreg32 fpreg32; 577 struct reg32 reg32; 578 struct ptrace_io_desc32 piod32; 579 struct ptrace_lwpinfo32 pl32; 580 struct ptrace_vm_entry32 pve32; 581 #endif 582 } r; 583 void *addr; 584 int error = 0; 585 #ifdef COMPAT_FREEBSD32 586 int wrap32 = 0; 587 588 if (SV_CURPROC_FLAG(SV_ILP32)) 589 wrap32 = 1; 590 #endif 591 AUDIT_ARG_PID(uap->pid); 592 AUDIT_ARG_CMD(uap->req); 593 AUDIT_ARG_VALUE(uap->data); 594 addr = &r; 595 switch (uap->req) { 596 case PT_GETREGS: 597 case PT_GETFPREGS: 598 case PT_GETDBREGS: 599 case PT_LWPINFO: 600 break; 601 case PT_SETREGS: 602 error = COPYIN(uap->addr, &r.reg, sizeof r.reg); 603 break; 604 case PT_SETFPREGS: 605 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg); 606 break; 607 case PT_SETDBREGS: 608 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg); 609 break; 610 case PT_IO: 611 error = COPYIN(uap->addr, &r.piod, sizeof r.piod); 612 break; 613 case PT_VM_ENTRY: 614 error = COPYIN(uap->addr, &r.pve, sizeof r.pve); 615 break; 616 default: 617 addr = uap->addr; 618 break; 619 } 620 if (error) 621 return (error); 622 623 error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data); 624 if (error) 625 return (error); 626 627 switch (uap->req) { 628 case PT_VM_ENTRY: 629 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve); 630 break; 631 case PT_IO: 632 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod); 633 break; 634 case PT_GETREGS: 635 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg); 636 break; 637 case PT_GETFPREGS: 638 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg); 639 break; 640 case PT_GETDBREGS: 641 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg); 642 break; 643 case PT_LWPINFO: 644 error = copyout(&r.pl, uap->addr, uap->data); 645 break; 646 } 647 648 return (error); 649 } 650 #undef COPYIN 651 #undef COPYOUT 652 653 #ifdef COMPAT_FREEBSD32 654 /* 655 * PROC_READ(regs, td2, addr); 656 * becomes either: 657 * proc_read_regs(td2, addr); 658 * or 659 * proc_read_regs32(td2, addr); 660 * .. except this is done at runtime. There is an additional 661 * complication in that PROC_WRITE disallows 32 bit consumers 662 * from writing to 64 bit address space targets. 663 */ 664 #define PROC_READ(w, t, a) wrap32 ? \ 665 proc_read_ ## w ## 32(t, a) : \ 666 proc_read_ ## w (t, a) 667 #define PROC_WRITE(w, t, a) wrap32 ? \ 668 (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \ 669 proc_write_ ## w (t, a) 670 #else 671 #define PROC_READ(w, t, a) proc_read_ ## w (t, a) 672 #define PROC_WRITE(w, t, a) proc_write_ ## w (t, a) 673 #endif 674 675 int 676 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) 677 { 678 struct iovec iov; 679 struct uio uio; 680 struct proc *curp, *p, *pp; 681 struct thread *td2 = NULL; 682 struct ptrace_io_desc *piod = NULL; 683 struct ptrace_lwpinfo *pl; 684 int error, write, tmp, num; 685 int proctree_locked = 0; 686 lwpid_t tid = 0, *buf; 687 #ifdef COMPAT_FREEBSD32 688 int wrap32 = 0, safe = 0; 689 struct ptrace_io_desc32 *piod32 = NULL; 690 struct ptrace_lwpinfo32 *pl32 = NULL; 691 struct ptrace_lwpinfo plr; 692 #endif 693 694 curp = td->td_proc; 695 696 /* Lock proctree before locking the process. */ 697 switch (req) { 698 case PT_TRACE_ME: 699 case PT_ATTACH: 700 case PT_STEP: 701 case PT_CONTINUE: 702 case PT_TO_SCE: 703 case PT_TO_SCX: 704 case PT_SYSCALL: 705 case PT_FOLLOW_FORK: 706 case PT_DETACH: 707 sx_xlock(&proctree_lock); 708 proctree_locked = 1; 709 break; 710 default: 711 break; 712 } 713 714 write = 0; 715 if (req == PT_TRACE_ME) { 716 p = td->td_proc; 717 PROC_LOCK(p); 718 } else { 719 if (pid <= PID_MAX) { 720 if ((p = pfind(pid)) == NULL) { 721 if (proctree_locked) 722 sx_xunlock(&proctree_lock); 723 return (ESRCH); 724 } 725 } else { 726 /* this is slow, should be optimized */ 727 sx_slock(&allproc_lock); 728 FOREACH_PROC_IN_SYSTEM(p) { 729 PROC_LOCK(p); 730 FOREACH_THREAD_IN_PROC(p, td2) { 731 if (td2->td_tid == pid) 732 break; 733 } 734 if (td2 != NULL) 735 break; /* proc lock held */ 736 PROC_UNLOCK(p); 737 } 738 sx_sunlock(&allproc_lock); 739 if (p == NULL) { 740 if (proctree_locked) 741 sx_xunlock(&proctree_lock); 742 return (ESRCH); 743 } 744 tid = pid; 745 pid = p->p_pid; 746 } 747 } 748 AUDIT_ARG_PROCESS(p); 749 750 if ((p->p_flag & P_WEXIT) != 0) { 751 error = ESRCH; 752 goto fail; 753 } 754 if ((error = p_cansee(td, p)) != 0) 755 goto fail; 756 757 if ((error = p_candebug(td, p)) != 0) 758 goto fail; 759 760 /* 761 * System processes can't be debugged. 762 */ 763 if ((p->p_flag & P_SYSTEM) != 0) { 764 error = EINVAL; 765 goto fail; 766 } 767 768 if (tid == 0) { 769 if ((p->p_flag & P_STOPPED_TRACE) != 0) { 770 KASSERT(p->p_xthread != NULL, ("NULL p_xthread")); 771 td2 = p->p_xthread; 772 } else { 773 td2 = FIRST_THREAD_IN_PROC(p); 774 } 775 tid = td2->td_tid; 776 } 777 778 #ifdef COMPAT_FREEBSD32 779 /* 780 * Test if we're a 32 bit client and what the target is. 781 * Set the wrap controls accordingly. 782 */ 783 if (SV_CURPROC_FLAG(SV_ILP32)) { 784 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32)) 785 safe = 1; 786 wrap32 = 1; 787 } 788 #endif 789 /* 790 * Permissions check 791 */ 792 switch (req) { 793 case PT_TRACE_ME: 794 /* Always legal. */ 795 break; 796 797 case PT_ATTACH: 798 /* Self */ 799 if (p->p_pid == td->td_proc->p_pid) { 800 error = EINVAL; 801 goto fail; 802 } 803 804 /* Already traced */ 805 if (p->p_flag & P_TRACED) { 806 error = EBUSY; 807 goto fail; 808 } 809 810 /* Can't trace an ancestor if you're being traced. */ 811 if (curp->p_flag & P_TRACED) { 812 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) { 813 if (pp == p) { 814 error = EINVAL; 815 goto fail; 816 } 817 } 818 } 819 820 821 /* OK */ 822 break; 823 824 case PT_CLEARSTEP: 825 /* Allow thread to clear single step for itself */ 826 if (td->td_tid == tid) 827 break; 828 829 /* FALLTHROUGH */ 830 default: 831 /* not being traced... */ 832 if ((p->p_flag & P_TRACED) == 0) { 833 error = EPERM; 834 goto fail; 835 } 836 837 /* not being traced by YOU */ 838 if (p->p_pptr != td->td_proc) { 839 error = EBUSY; 840 goto fail; 841 } 842 843 /* not currently stopped */ 844 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 || 845 p->p_suspcount != p->p_numthreads || 846 (p->p_flag & P_WAITED) == 0) { 847 error = EBUSY; 848 goto fail; 849 } 850 851 if ((p->p_flag & P_STOPPED_TRACE) == 0) { 852 static int count = 0; 853 if (count++ == 0) 854 printf("P_STOPPED_TRACE not set.\n"); 855 } 856 857 /* OK */ 858 break; 859 } 860 861 /* Keep this process around until we finish this request. */ 862 _PHOLD(p); 863 864 #ifdef FIX_SSTEP 865 /* 866 * Single step fixup ala procfs 867 */ 868 FIX_SSTEP(td2); 869 #endif 870 871 /* 872 * Actually do the requests 873 */ 874 875 td->td_retval[0] = 0; 876 877 switch (req) { 878 case PT_TRACE_ME: 879 /* set my trace flag and "owner" so it can read/write me */ 880 p->p_flag |= P_TRACED; 881 p->p_oppid = p->p_pptr->p_pid; 882 break; 883 884 case PT_ATTACH: 885 /* security check done above */ 886 p->p_flag |= P_TRACED; 887 p->p_oppid = p->p_pptr->p_pid; 888 if (p->p_pptr != td->td_proc) 889 proc_reparent(p, td->td_proc); 890 data = SIGSTOP; 891 goto sendsig; /* in PT_CONTINUE below */ 892 893 case PT_CLEARSTEP: 894 error = ptrace_clear_single_step(td2); 895 break; 896 897 case PT_SETSTEP: 898 error = ptrace_single_step(td2); 899 break; 900 901 case PT_SUSPEND: 902 td2->td_dbgflags |= TDB_SUSPEND; 903 thread_lock(td2); 904 td2->td_flags |= TDF_NEEDSUSPCHK; 905 thread_unlock(td2); 906 break; 907 908 case PT_RESUME: 909 td2->td_dbgflags &= ~TDB_SUSPEND; 910 break; 911 912 case PT_FOLLOW_FORK: 913 if (data) 914 p->p_flag |= P_FOLLOWFORK; 915 else 916 p->p_flag &= ~P_FOLLOWFORK; 917 break; 918 919 case PT_STEP: 920 case PT_CONTINUE: 921 case PT_TO_SCE: 922 case PT_TO_SCX: 923 case PT_SYSCALL: 924 case PT_DETACH: 925 /* Zero means do not send any signal */ 926 if (data < 0 || data > _SIG_MAXSIG) { 927 error = EINVAL; 928 break; 929 } 930 931 switch (req) { 932 case PT_STEP: 933 error = ptrace_single_step(td2); 934 if (error) 935 goto out; 936 break; 937 case PT_CONTINUE: 938 case PT_TO_SCE: 939 case PT_TO_SCX: 940 case PT_SYSCALL: 941 if (addr != (void *)1) { 942 error = ptrace_set_pc(td2, 943 (u_long)(uintfptr_t)addr); 944 if (error) 945 goto out; 946 } 947 switch (req) { 948 case PT_TO_SCE: 949 p->p_stops |= S_PT_SCE; 950 break; 951 case PT_TO_SCX: 952 p->p_stops |= S_PT_SCX; 953 break; 954 case PT_SYSCALL: 955 p->p_stops |= S_PT_SCE | S_PT_SCX; 956 break; 957 } 958 break; 959 case PT_DETACH: 960 /* reset process parent */ 961 if (p->p_oppid != p->p_pptr->p_pid) { 962 struct proc *pp; 963 964 PROC_LOCK(p->p_pptr); 965 sigqueue_take(p->p_ksi); 966 PROC_UNLOCK(p->p_pptr); 967 968 PROC_UNLOCK(p); 969 pp = pfind(p->p_oppid); 970 if (pp == NULL) 971 pp = initproc; 972 else 973 PROC_UNLOCK(pp); 974 PROC_LOCK(p); 975 proc_reparent(p, pp); 976 if (pp == initproc) 977 p->p_sigparent = SIGCHLD; 978 } 979 p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK); 980 p->p_oppid = 0; 981 982 /* should we send SIGCHLD? */ 983 /* childproc_continued(p); */ 984 break; 985 } 986 987 sendsig: 988 if (proctree_locked) { 989 sx_xunlock(&proctree_lock); 990 proctree_locked = 0; 991 } 992 p->p_xstat = data; 993 p->p_xthread = NULL; 994 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) { 995 /* deliver or queue signal */ 996 td2->td_dbgflags &= ~TDB_XSIG; 997 td2->td_xsig = data; 998 999 if (req == PT_DETACH) { 1000 struct thread *td3; 1001 FOREACH_THREAD_IN_PROC(p, td3) { 1002 td3->td_dbgflags &= ~TDB_SUSPEND; 1003 } 1004 } 1005 /* 1006 * unsuspend all threads, to not let a thread run, 1007 * you should use PT_SUSPEND to suspend it before 1008 * continuing process. 1009 */ 1010 PROC_SLOCK(p); 1011 p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED); 1012 thread_unsuspend(p); 1013 PROC_SUNLOCK(p); 1014 } else { 1015 if (data) 1016 psignal(p, data); 1017 } 1018 break; 1019 1020 case PT_WRITE_I: 1021 case PT_WRITE_D: 1022 td2->td_dbgflags |= TDB_USERWR; 1023 write = 1; 1024 /* FALLTHROUGH */ 1025 case PT_READ_I: 1026 case PT_READ_D: 1027 PROC_UNLOCK(p); 1028 tmp = 0; 1029 /* write = 0 set above */ 1030 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; 1031 iov.iov_len = sizeof(int); 1032 uio.uio_iov = &iov; 1033 uio.uio_iovcnt = 1; 1034 uio.uio_offset = (off_t)(uintptr_t)addr; 1035 uio.uio_resid = sizeof(int); 1036 uio.uio_segflg = UIO_SYSSPACE; /* i.e.: the uap */ 1037 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 1038 uio.uio_td = td; 1039 error = proc_rwmem(p, &uio); 1040 if (uio.uio_resid != 0) { 1041 /* 1042 * XXX proc_rwmem() doesn't currently return ENOSPC, 1043 * so I think write() can bogusly return 0. 1044 * XXX what happens for short writes? We don't want 1045 * to write partial data. 1046 * XXX proc_rwmem() returns EPERM for other invalid 1047 * addresses. Convert this to EINVAL. Does this 1048 * clobber returns of EPERM for other reasons? 1049 */ 1050 if (error == 0 || error == ENOSPC || error == EPERM) 1051 error = EINVAL; /* EOF */ 1052 } 1053 if (!write) 1054 td->td_retval[0] = tmp; 1055 PROC_LOCK(p); 1056 break; 1057 1058 case PT_IO: 1059 #ifdef COMPAT_FREEBSD32 1060 if (wrap32) { 1061 piod32 = addr; 1062 iov.iov_base = (void *)(uintptr_t)piod32->piod_addr; 1063 iov.iov_len = piod32->piod_len; 1064 uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs; 1065 uio.uio_resid = piod32->piod_len; 1066 } else 1067 #endif 1068 { 1069 piod = addr; 1070 iov.iov_base = piod->piod_addr; 1071 iov.iov_len = piod->piod_len; 1072 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; 1073 uio.uio_resid = piod->piod_len; 1074 } 1075 uio.uio_iov = &iov; 1076 uio.uio_iovcnt = 1; 1077 uio.uio_segflg = UIO_USERSPACE; 1078 uio.uio_td = td; 1079 #ifdef COMPAT_FREEBSD32 1080 tmp = wrap32 ? piod32->piod_op : piod->piod_op; 1081 #else 1082 tmp = piod->piod_op; 1083 #endif 1084 switch (tmp) { 1085 case PIOD_READ_D: 1086 case PIOD_READ_I: 1087 uio.uio_rw = UIO_READ; 1088 break; 1089 case PIOD_WRITE_D: 1090 case PIOD_WRITE_I: 1091 td2->td_dbgflags |= TDB_USERWR; 1092 uio.uio_rw = UIO_WRITE; 1093 break; 1094 default: 1095 error = EINVAL; 1096 goto out; 1097 } 1098 PROC_UNLOCK(p); 1099 error = proc_rwmem(p, &uio); 1100 #ifdef COMPAT_FREEBSD32 1101 if (wrap32) 1102 piod32->piod_len -= uio.uio_resid; 1103 else 1104 #endif 1105 piod->piod_len -= uio.uio_resid; 1106 PROC_LOCK(p); 1107 break; 1108 1109 case PT_KILL: 1110 data = SIGKILL; 1111 goto sendsig; /* in PT_CONTINUE above */ 1112 1113 case PT_SETREGS: 1114 td2->td_dbgflags |= TDB_USERWR; 1115 error = PROC_WRITE(regs, td2, addr); 1116 break; 1117 1118 case PT_GETREGS: 1119 error = PROC_READ(regs, td2, addr); 1120 break; 1121 1122 case PT_SETFPREGS: 1123 td2->td_dbgflags |= TDB_USERWR; 1124 error = PROC_WRITE(fpregs, td2, addr); 1125 break; 1126 1127 case PT_GETFPREGS: 1128 error = PROC_READ(fpregs, td2, addr); 1129 break; 1130 1131 case PT_SETDBREGS: 1132 td2->td_dbgflags |= TDB_USERWR; 1133 error = PROC_WRITE(dbregs, td2, addr); 1134 break; 1135 1136 case PT_GETDBREGS: 1137 error = PROC_READ(dbregs, td2, addr); 1138 break; 1139 1140 case PT_LWPINFO: 1141 if (data <= 0 || 1142 #ifdef COMPAT_FREEBSD32 1143 (!wrap32 && data > sizeof(*pl)) || 1144 (wrap32 && data > sizeof(*pl32))) { 1145 #else 1146 data > sizeof(*pl)) { 1147 #endif 1148 error = EINVAL; 1149 break; 1150 } 1151 #ifdef COMPAT_FREEBSD32 1152 if (wrap32) { 1153 pl = &plr; 1154 pl32 = addr; 1155 } else 1156 #endif 1157 pl = addr; 1158 pl->pl_lwpid = td2->td_tid; 1159 pl->pl_flags = 0; 1160 if (td2->td_dbgflags & TDB_XSIG) { 1161 pl->pl_event = PL_EVENT_SIGNAL; 1162 if (td2->td_dbgksi.ksi_signo != 0 && 1163 #ifdef COMPAT_FREEBSD32 1164 ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo, 1165 pl_siginfo) + sizeof(pl->pl_siginfo)) || 1166 (wrap32 && data >= offsetof(struct ptrace_lwpinfo32, 1167 pl_siginfo) + sizeof(struct siginfo32))) 1168 #else 1169 data >= offsetof(struct ptrace_lwpinfo, pl_siginfo) 1170 + sizeof(pl->pl_siginfo) 1171 #endif 1172 ){ 1173 pl->pl_flags |= PL_FLAG_SI; 1174 pl->pl_siginfo = td2->td_dbgksi.ksi_info; 1175 } 1176 } 1177 if ((pl->pl_flags & PL_FLAG_SI) == 0) 1178 bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo)); 1179 if (td2->td_dbgflags & TDB_SCE) 1180 pl->pl_flags |= PL_FLAG_SCE; 1181 else if (td2->td_dbgflags & TDB_SCX) 1182 pl->pl_flags |= PL_FLAG_SCX; 1183 if (td2->td_dbgflags & TDB_EXEC) 1184 pl->pl_flags |= PL_FLAG_EXEC; 1185 if (td2->td_dbgflags & TDB_FORK) { 1186 pl->pl_flags |= PL_FLAG_FORKED; 1187 pl->pl_child_pid = td2->td_dbg_forked; 1188 } 1189 pl->pl_sigmask = td2->td_sigmask; 1190 pl->pl_siglist = td2->td_siglist; 1191 strcpy(pl->pl_tdname, td2->td_name); 1192 #ifdef COMPAT_FREEBSD32 1193 if (wrap32) 1194 ptrace_lwpinfo_to32(pl, pl32); 1195 #endif 1196 break; 1197 1198 case PT_GETNUMLWPS: 1199 td->td_retval[0] = p->p_numthreads; 1200 break; 1201 1202 case PT_GETLWPLIST: 1203 if (data <= 0) { 1204 error = EINVAL; 1205 break; 1206 } 1207 num = imin(p->p_numthreads, data); 1208 PROC_UNLOCK(p); 1209 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK); 1210 tmp = 0; 1211 PROC_LOCK(p); 1212 FOREACH_THREAD_IN_PROC(p, td2) { 1213 if (tmp >= num) 1214 break; 1215 buf[tmp++] = td2->td_tid; 1216 } 1217 PROC_UNLOCK(p); 1218 error = copyout(buf, addr, tmp * sizeof(lwpid_t)); 1219 free(buf, M_TEMP); 1220 if (!error) 1221 td->td_retval[0] = tmp; 1222 PROC_LOCK(p); 1223 break; 1224 1225 case PT_VM_TIMESTAMP: 1226 td->td_retval[0] = p->p_vmspace->vm_map.timestamp; 1227 break; 1228 1229 case PT_VM_ENTRY: 1230 PROC_UNLOCK(p); 1231 #ifdef COMPAT_FREEBSD32 1232 if (wrap32) 1233 error = ptrace_vm_entry32(td, p, addr); 1234 else 1235 #endif 1236 error = ptrace_vm_entry(td, p, addr); 1237 PROC_LOCK(p); 1238 break; 1239 1240 default: 1241 #ifdef __HAVE_PTRACE_MACHDEP 1242 if (req >= PT_FIRSTMACH) { 1243 PROC_UNLOCK(p); 1244 error = cpu_ptrace(td2, req, addr, data); 1245 PROC_LOCK(p); 1246 } else 1247 #endif 1248 /* Unknown request. */ 1249 error = EINVAL; 1250 break; 1251 } 1252 1253 out: 1254 /* Drop our hold on this process now that the request has completed. */ 1255 _PRELE(p); 1256 fail: 1257 PROC_UNLOCK(p); 1258 if (proctree_locked) 1259 sx_xunlock(&proctree_lock); 1260 return (error); 1261 } 1262 #undef PROC_READ 1263 #undef PROC_WRITE 1264 1265 /* 1266 * Stop a process because of a debugging event; 1267 * stay stopped until p->p_step is cleared 1268 * (cleared by PIOCCONT in procfs). 1269 */ 1270 void 1271 stopevent(struct proc *p, unsigned int event, unsigned int val) 1272 { 1273 1274 PROC_LOCK_ASSERT(p, MA_OWNED); 1275 p->p_step = 1; 1276 do { 1277 p->p_xstat = val; 1278 p->p_xthread = NULL; 1279 p->p_stype = event; /* Which event caused the stop? */ 1280 wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */ 1281 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0); 1282 } while (p->p_step); 1283 }
Cache object: 07b3c15e8774e862fa1050603f3e4745
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