1 /* $OpenBSD: sys_process.c,v 1.97 2024/04/02 08:27:22 deraadt Exp $ */ 2 /* $NetBSD: sys_process.c,v 1.55 1996/05/15 06:17:47 tls Exp $ */ 3 4 /*- 5 * Copyright (c) 1994 Christopher G. Demetriou. All rights reserved. 6 * Copyright (c) 1982, 1986, 1989, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93 39 */ 40 41 /* 42 * References: 43 * (1) Bach's "The Design of the UNIX Operating System", 44 * (2) sys/miscfs/procfs from UCB's 4.4BSD-Lite distribution, 45 * (3) the "4.4BSD Programmer's Reference Manual" published 46 * by USENIX and O'Reilly & Associates. 47 * The 4.4BSD PRM does a reasonably good job of documenting what the various 48 * ptrace() requests should actually do, and its text is quoted several times 49 * in this file. 50 */ 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/exec.h> 55 #include <sys/proc.h> 56 #include <sys/signalvar.h> 57 #include <sys/errno.h> 58 #include <sys/malloc.h> 59 #include <sys/ptrace.h> 60 #include <sys/uio.h> 61 #include <sys/sched.h> 62 #include <sys/exec_elf.h> 63 64 #include <sys/mount.h> 65 #include <sys/syscallargs.h> 66 67 #include <uvm/uvm_extern.h> 68 69 #include <machine/reg.h> 70 71 #ifdef PTRACE 72 73 static inline int process_checktracestate(struct process *_curpr, 74 struct process *_tr, struct proc *_t); 75 static inline struct process *process_tprfind(pid_t _tpid, struct proc **_tp); 76 77 int ptrace_ctrl(struct proc *, int, pid_t, caddr_t, int); 78 int ptrace_ustate(struct proc *, int, pid_t, void *, int, register_t *); 79 int ptrace_kstate(struct proc *, int, pid_t, void *); 80 81 int global_ptrace; /* permit tracing of not children */ 82 83 84 /* 85 * Process debugging system call. 86 */ 87 int 88 sys_ptrace(struct proc *p, void *v, register_t *retval) 89 { 90 struct sys_ptrace_args /* { 91 syscallarg(int) req; 92 syscallarg(pid_t) pid; 93 syscallarg(caddr_t) addr; 94 syscallarg(int) data; 95 } */ *uap = v; 96 int req = SCARG(uap, req); 97 pid_t pid = SCARG(uap, pid); 98 caddr_t uaddr = SCARG(uap, addr); /* userspace */ 99 void *kaddr = NULL; /* kernelspace */ 100 int data = SCARG(uap, data); 101 union { 102 struct ptrace_thread_state u_pts; 103 struct ptrace_io_desc u_piod; 104 struct ptrace_event u_pe; 105 struct ptrace_state u_ps; 106 register_t u_wcookie; 107 register_t u_pacmask[2]; 108 } u; 109 int size = 0; 110 enum { NONE, IN, IN_ALLOC, OUT, OUT_ALLOC, IN_OUT } mode; 111 int kstate = 0; 112 int error; 113 114 *retval = 0; 115 116 /* Figure out what sort of copyin/out operations we'll do */ 117 switch (req) { 118 case PT_TRACE_ME: 119 case PT_CONTINUE: 120 case PT_KILL: 121 case PT_ATTACH: 122 case PT_DETACH: 123 #ifdef PT_STEP 124 case PT_STEP: 125 #endif 126 /* control operations do no copyin/out; dispatch directly */ 127 return ptrace_ctrl(p, req, pid, uaddr, data); 128 129 case PT_READ_I: 130 case PT_READ_D: 131 case PT_WRITE_I: 132 case PT_WRITE_D: 133 mode = NONE; 134 break; 135 case PT_IO: 136 mode = IN_OUT; 137 size = sizeof u.u_piod; 138 data = size; /* suppress the data == size check */ 139 break; 140 case PT_GET_THREAD_FIRST: 141 mode = OUT; 142 size = sizeof u.u_pts; 143 kstate = 1; 144 break; 145 case PT_GET_THREAD_NEXT: 146 mode = IN_OUT; 147 size = sizeof u.u_pts; 148 kstate = 1; 149 break; 150 case PT_GET_EVENT_MASK: 151 mode = OUT; 152 size = sizeof u.u_pe; 153 kstate = 1; 154 break; 155 case PT_SET_EVENT_MASK: 156 mode = IN; 157 size = sizeof u.u_pe; 158 kstate = 1; 159 break; 160 case PT_GET_PROCESS_STATE: 161 mode = OUT; 162 size = sizeof u.u_ps; 163 kstate = 1; 164 break; 165 case PT_GETREGS: 166 mode = OUT_ALLOC; 167 size = sizeof(struct reg); 168 break; 169 case PT_SETREGS: 170 mode = IN_ALLOC; 171 size = sizeof(struct reg); 172 break; 173 #ifdef PT_GETFPREGS 174 case PT_GETFPREGS: 175 mode = OUT_ALLOC; 176 size = sizeof(struct fpreg); 177 break; 178 #endif 179 #ifdef PT_SETFPREGS 180 case PT_SETFPREGS: 181 mode = IN_ALLOC; 182 size = sizeof(struct fpreg); 183 break; 184 #endif 185 #ifdef PT_GETXMMREGS 186 case PT_GETXMMREGS: 187 mode = OUT_ALLOC; 188 size = sizeof(struct xmmregs); 189 break; 190 #endif 191 #ifdef PT_SETXMMREGS 192 case PT_SETXMMREGS: 193 mode = IN_ALLOC; 194 size = sizeof(struct xmmregs); 195 break; 196 #endif 197 #ifdef PT_WCOOKIE 198 case PT_WCOOKIE: 199 mode = OUT; 200 size = sizeof u.u_wcookie; 201 data = size; /* suppress the data == size check */ 202 break; 203 #endif 204 #ifdef PT_PACMASK 205 case PT_PACMASK: 206 mode = OUT; 207 size = sizeof u.u_pacmask; 208 break; 209 #endif 210 default: 211 return EINVAL; 212 } 213 214 215 /* Now do any copyin()s and allocations in a consistent manner */ 216 switch (mode) { 217 case NONE: 218 kaddr = uaddr; 219 break; 220 case IN: 221 case IN_OUT: 222 case OUT: 223 KASSERT(size <= sizeof u); 224 if (data != size) 225 return EINVAL; 226 if (mode == OUT) 227 memset(&u, 0, size); 228 else { /* IN or IN_OUT */ 229 if ((error = copyin(uaddr, &u, size))) 230 return error; 231 } 232 kaddr = &u; 233 break; 234 case IN_ALLOC: 235 kaddr = malloc(size, M_TEMP, M_WAITOK); 236 if ((error = copyin(uaddr, kaddr, size))) { 237 free(kaddr, M_TEMP, size); 238 return error; 239 } 240 break; 241 case OUT_ALLOC: 242 kaddr = malloc(size, M_TEMP, M_WAITOK | M_ZERO); 243 break; 244 } 245 246 if (kstate) 247 error = ptrace_kstate(p, req, pid, kaddr); 248 else 249 error = ptrace_ustate(p, req, pid, kaddr, data, retval); 250 251 /* Do any copyout()s and frees */ 252 if (error == 0) { 253 switch (mode) { 254 case NONE: 255 case IN: 256 case IN_ALLOC: 257 break; 258 case IN_OUT: 259 case OUT: 260 error = copyout(&u, uaddr, size); 261 if (req == PT_IO) { 262 /* historically, errors here are ignored */ 263 error = 0; 264 } 265 break; 266 case OUT_ALLOC: 267 error = copyout(kaddr, uaddr, size); 268 break; 269 } 270 } 271 272 if (mode == IN_ALLOC || mode == OUT_ALLOC) 273 free(kaddr, M_TEMP, size); 274 return error; 275 } 276 277 /* 278 * ptrace control requests: attach, detach, continue, kill, single-step, etc 279 */ 280 int 281 ptrace_ctrl(struct proc *p, int req, pid_t pid, caddr_t addr, int data) 282 { 283 struct proc *t; /* target thread */ 284 struct process *tr; /* target process */ 285 int error = 0; 286 int s; 287 288 switch (req) { 289 case PT_TRACE_ME: 290 /* Just set the trace flag. */ 291 tr = p->p_p; 292 if (ISSET(tr->ps_flags, PS_TRACED)) 293 return EBUSY; 294 atomic_setbits_int(&tr->ps_flags, PS_TRACED); 295 tr->ps_oppid = tr->ps_pptr->ps_pid; 296 if (tr->ps_ptstat == NULL) 297 tr->ps_ptstat = malloc(sizeof(*tr->ps_ptstat), 298 M_SUBPROC, M_WAITOK); 299 memset(tr->ps_ptstat, 0, sizeof(*tr->ps_ptstat)); 300 return 0; 301 302 /* calls that only operate on the PID */ 303 case PT_KILL: 304 case PT_ATTACH: 305 case PT_DETACH: 306 /* Find the process we're supposed to be operating on. */ 307 if ((tr = prfind(pid)) == NULL) { 308 error = ESRCH; 309 goto fail; 310 } 311 t = TAILQ_FIRST(&tr->ps_threads); 312 break; 313 314 /* calls that accept a PID or a thread ID */ 315 case PT_CONTINUE: 316 #ifdef PT_STEP 317 case PT_STEP: 318 #endif 319 if ((tr = process_tprfind(pid, &t)) == NULL) { 320 error = ESRCH; 321 goto fail; 322 } 323 break; 324 } 325 326 /* Check permissions/state */ 327 if (req != PT_ATTACH) { 328 /* Check that the data is a valid signal number or zero. */ 329 if (req != PT_KILL && (data < 0 || data >= NSIG)) { 330 error = EINVAL; 331 goto fail; 332 } 333 334 /* Most operations require the target to already be traced */ 335 if ((error = process_checktracestate(p->p_p, tr, t))) 336 goto fail; 337 338 /* Do single-step fixup if needed. */ 339 FIX_SSTEP(t); 340 } else { 341 /* 342 * PT_ATTACH is the opposite; you can't attach to a process if: 343 * (1) it's the process that's doing the attaching, 344 */ 345 if (tr == p->p_p) { 346 error = EINVAL; 347 goto fail; 348 } 349 350 /* 351 * (2) it's a system process 352 */ 353 if (ISSET(tr->ps_flags, PS_SYSTEM)) { 354 error = EPERM; 355 goto fail; 356 } 357 358 /* 359 * (3) it's already being traced, or 360 */ 361 if (ISSET(tr->ps_flags, PS_TRACED)) { 362 error = EBUSY; 363 goto fail; 364 } 365 366 /* 367 * (4) it's in the middle of execve(2) 368 */ 369 if (ISSET(tr->ps_flags, PS_INEXEC)) { 370 error = EAGAIN; 371 goto fail; 372 } 373 374 /* 375 * (5) it's not owned by you, or the last exec 376 * gave us setuid/setgid privs (unless 377 * you're root), or... 378 * 379 * [Note: once PS_SUGID or PS_SUGIDEXEC gets set in 380 * execve(), they stay set until the process does 381 * another execve(). Hence this prevents a setuid 382 * process which revokes its special privileges using 383 * setuid() from being traced. This is good security.] 384 */ 385 if ((tr->ps_ucred->cr_ruid != p->p_ucred->cr_ruid || 386 ISSET(tr->ps_flags, PS_SUGIDEXEC | PS_SUGID)) && 387 (error = suser(p)) != 0) 388 goto fail; 389 390 /* 391 * (5.5) it's not a child of the tracing process. 392 */ 393 if (global_ptrace == 0 && !inferior(tr, p->p_p) && 394 (error = suser(p)) != 0) 395 goto fail; 396 397 /* 398 * (6) ...it's init, which controls the security level 399 * of the entire system, and the system was not 400 * compiled with permanently insecure mode turned 401 * on. 402 */ 403 if ((tr->ps_pid == 1) && (securelevel > -1)) { 404 error = EPERM; 405 goto fail; 406 } 407 408 /* 409 * (7) it's an ancestor of the current process and 410 * not init (because that would create a loop in 411 * the process graph). 412 */ 413 if (tr->ps_pid != 1 && inferior(p->p_p, tr)) { 414 error = EINVAL; 415 goto fail; 416 } 417 } 418 419 switch (req) { 420 421 #ifdef PT_STEP 422 case PT_STEP: 423 /* 424 * From the 4.4BSD PRM: 425 * "Execution continues as in request PT_CONTINUE; however 426 * as soon as possible after execution of at least one 427 * instruction, execution stops again. [ ... ]" 428 */ 429 #endif 430 case PT_CONTINUE: 431 /* 432 * From the 4.4BSD PRM: 433 * "The data argument is taken as a signal number and the 434 * child's execution continues at location addr as if it 435 * incurred that signal. Normally the signal number will 436 * be either 0 to indicate that the signal that caused the 437 * stop should be ignored, or that value fetched out of 438 * the process's image indicating which signal caused 439 * the stop. If addr is (int *)1 then execution continues 440 * from where it stopped." 441 */ 442 443 if (pid < THREAD_PID_OFFSET && tr->ps_single) 444 t = tr->ps_single; 445 446 /* If the address parameter is not (int *)1, set the pc. */ 447 if ((int *)addr != (int *)1) 448 if ((error = process_set_pc(t, addr)) != 0) 449 goto fail; 450 451 #ifdef PT_STEP 452 /* 453 * Arrange for a single-step, if that's requested and possible. 454 */ 455 error = process_sstep(t, req == PT_STEP); 456 if (error) 457 goto fail; 458 #endif 459 goto sendsig; 460 461 case PT_DETACH: 462 /* 463 * From the 4.4BSD PRM: 464 * "The data argument is taken as a signal number and the 465 * child's execution continues at location addr as if it 466 * incurred that signal. Normally the signal number will 467 * be either 0 to indicate that the signal that caused the 468 * stop should be ignored, or that value fetched out of 469 * the process's image indicating which signal caused 470 * the stop. If addr is (int *)1 then execution continues 471 * from where it stopped." 472 */ 473 474 if (pid < THREAD_PID_OFFSET && tr->ps_single) 475 t = tr->ps_single; 476 477 #ifdef PT_STEP 478 /* 479 * Stop single stepping. 480 */ 481 error = process_sstep(t, 0); 482 if (error) 483 goto fail; 484 #endif 485 486 process_untrace(tr); 487 atomic_clearbits_int(&tr->ps_flags, PS_WAITED); 488 489 sendsig: 490 memset(tr->ps_ptstat, 0, sizeof(*tr->ps_ptstat)); 491 492 /* Finally, deliver the requested signal (or none). */ 493 if (t->p_stat == SSTOP) { 494 tr->ps_xsig = data; 495 SCHED_LOCK(s); 496 unsleep(t); 497 setrunnable(t); 498 SCHED_UNLOCK(s); 499 } else { 500 if (data != 0) 501 psignal(t, data); 502 } 503 break; 504 505 case PT_KILL: 506 if (pid < THREAD_PID_OFFSET && tr->ps_single) 507 t = tr->ps_single; 508 509 /* just send the process a KILL signal. */ 510 data = SIGKILL; 511 goto sendsig; /* in PT_CONTINUE, above. */ 512 513 case PT_ATTACH: 514 /* 515 * As was done in procfs: 516 * Go ahead and set the trace flag. 517 * Save the old parent (it's reset in 518 * _DETACH, and also in kern_exit.c:wait4() 519 * Reparent the process so that the tracing 520 * proc gets to see all the action. 521 * Stop the target. 522 */ 523 atomic_setbits_int(&tr->ps_flags, PS_TRACED); 524 tr->ps_oppid = tr->ps_pptr->ps_pid; 525 process_reparent(tr, p->p_p); 526 if (tr->ps_ptstat == NULL) 527 tr->ps_ptstat = malloc(sizeof(*tr->ps_ptstat), 528 M_SUBPROC, M_WAITOK); 529 data = SIGSTOP; 530 goto sendsig; 531 default: 532 KASSERTMSG(0, "%s: unhandled request %d", __func__, req); 533 break; 534 } 535 536 fail: 537 return error; 538 } 539 540 /* 541 * ptrace kernel-state requests: thread list, event mask, process state 542 */ 543 int 544 ptrace_kstate(struct proc *p, int req, pid_t pid, void *addr) 545 { 546 struct process *tr; /* target process */ 547 struct ptrace_event *pe = addr; 548 int error; 549 550 KASSERT((p->p_flag & P_SYSTEM) == 0); 551 552 /* Find the process we're supposed to be operating on. */ 553 if ((tr = prfind(pid)) == NULL) 554 return ESRCH; 555 556 if ((error = process_checktracestate(p->p_p, tr, NULL))) 557 return error; 558 559 switch (req) { 560 case PT_GET_THREAD_FIRST: 561 case PT_GET_THREAD_NEXT: 562 { 563 struct ptrace_thread_state *pts = addr; 564 struct proc *t; 565 566 if (req == PT_GET_THREAD_NEXT) { 567 t = tfind_user(pts->pts_tid, tr); 568 if (t == NULL || ISSET(t->p_flag, P_WEXIT)) 569 return ESRCH; 570 t = TAILQ_NEXT(t, p_thr_link); 571 } else { 572 t = TAILQ_FIRST(&tr->ps_threads); 573 } 574 575 if (t == NULL) 576 pts->pts_tid = -1; 577 else 578 pts->pts_tid = t->p_tid + THREAD_PID_OFFSET; 579 return 0; 580 } 581 } 582 583 switch (req) { 584 case PT_GET_EVENT_MASK: 585 pe->pe_set_event = tr->ps_ptmask; 586 break; 587 case PT_SET_EVENT_MASK: 588 tr->ps_ptmask = pe->pe_set_event; 589 break; 590 case PT_GET_PROCESS_STATE: 591 if (tr->ps_single) 592 tr->ps_ptstat->pe_tid = 593 tr->ps_single->p_tid + THREAD_PID_OFFSET; 594 memcpy(addr, tr->ps_ptstat, sizeof *tr->ps_ptstat); 595 break; 596 default: 597 KASSERTMSG(0, "%s: unhandled request %d", __func__, req); 598 break; 599 } 600 601 return 0; 602 } 603 604 /* 605 * ptrace user-state requests: memory access, registers, stack cookie 606 */ 607 int 608 ptrace_ustate(struct proc *p, int req, pid_t pid, void *addr, int data, 609 register_t *retval) 610 { 611 struct proc *t; /* target thread */ 612 struct process *tr; /* target process */ 613 struct uio uio; 614 struct iovec iov; 615 int error, write; 616 int temp = 0; 617 618 KASSERT((p->p_flag & P_SYSTEM) == 0); 619 620 /* Accept either PID or TID */ 621 if ((tr = process_tprfind(pid, &t)) == NULL) 622 return ESRCH; 623 624 if ((error = process_checktracestate(p->p_p, tr, t))) 625 return error; 626 627 FIX_SSTEP(t); 628 629 /* Now do the operation. */ 630 write = 0; 631 632 if ((error = process_checkioperm(p, tr)) != 0) 633 return error; 634 635 switch (req) { 636 case PT_WRITE_I: /* XXX no separate I and D spaces */ 637 case PT_WRITE_D: 638 write = 1; 639 temp = data; 640 case PT_READ_I: /* XXX no separate I and D spaces */ 641 case PT_READ_D: 642 /* write = 0 done above. */ 643 iov.iov_base = (caddr_t)&temp; 644 iov.iov_len = sizeof(int); 645 uio.uio_iov = &iov; 646 uio.uio_iovcnt = 1; 647 uio.uio_offset = (off_t)(vaddr_t)addr; 648 uio.uio_resid = sizeof(int); 649 uio.uio_segflg = UIO_SYSSPACE; 650 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 651 uio.uio_procp = p; 652 error = process_domem(p, tr, &uio, write ? PT_WRITE_I : 653 PT_READ_I); 654 if (write == 0) 655 *retval = temp; 656 return error; 657 658 case PT_IO: 659 { 660 struct ptrace_io_desc *piod = addr; 661 662 iov.iov_base = piod->piod_addr; 663 iov.iov_len = piod->piod_len; 664 uio.uio_iov = &iov; 665 uio.uio_iovcnt = 1; 666 uio.uio_offset = (off_t)(vaddr_t)piod->piod_offs; 667 uio.uio_resid = piod->piod_len; 668 uio.uio_segflg = UIO_USERSPACE; 669 uio.uio_procp = p; 670 switch (piod->piod_op) { 671 case PIOD_READ_I: 672 req = PT_READ_I; 673 uio.uio_rw = UIO_READ; 674 break; 675 case PIOD_READ_D: 676 req = PT_READ_D; 677 uio.uio_rw = UIO_READ; 678 break; 679 case PIOD_WRITE_I: 680 req = PT_WRITE_I; 681 uio.uio_rw = UIO_WRITE; 682 break; 683 case PIOD_WRITE_D: 684 req = PT_WRITE_D; 685 uio.uio_rw = UIO_WRITE; 686 break; 687 case PIOD_READ_AUXV: 688 req = PT_READ_D; 689 uio.uio_rw = UIO_READ; 690 temp = ELF_AUX_WORDS * sizeof(char *); 691 if (uio.uio_offset > temp) 692 return EIO; 693 if (uio.uio_resid > temp - uio.uio_offset) 694 uio.uio_resid = temp - uio.uio_offset; 695 piod->piod_len = iov.iov_len = uio.uio_resid; 696 uio.uio_offset += tr->ps_auxinfo; 697 #ifdef MACHINE_STACK_GROWS_UP 698 if (uio.uio_offset < (off_t)tr->ps_strings) 699 return EIO; 700 #else 701 if (uio.uio_offset > (off_t)tr->ps_strings) 702 return EIO; 703 if ((uio.uio_offset + uio.uio_resid) > 704 (off_t)tr->ps_strings) 705 uio.uio_resid = (off_t)tr->ps_strings - 706 uio.uio_offset; 707 #endif 708 break; 709 default: 710 return EINVAL; 711 } 712 error = process_domem(p, tr, &uio, req); 713 piod->piod_len -= uio.uio_resid; 714 return error; 715 } 716 717 case PT_SETREGS: 718 return process_write_regs(t, addr); 719 case PT_GETREGS: 720 return process_read_regs(t, addr); 721 722 #ifdef PT_SETFPREGS 723 case PT_SETFPREGS: 724 return process_write_fpregs(t, addr); 725 #endif 726 #ifdef PT_SETFPREGS 727 case PT_GETFPREGS: 728 return process_read_fpregs(t, addr); 729 #endif 730 #ifdef PT_SETXMMREGS 731 case PT_SETXMMREGS: 732 return process_write_xmmregs(t, addr); 733 #endif 734 #ifdef PT_SETXMMREGS 735 case PT_GETXMMREGS: 736 return process_read_xmmregs(t, addr); 737 #endif 738 #ifdef PT_WCOOKIE 739 case PT_WCOOKIE: 740 *(register_t *)addr = process_get_wcookie(t); 741 return 0; 742 #endif 743 #ifdef PT_PACMASK 744 case PT_PACMASK: 745 ((register_t *)addr)[0] = process_get_pacmask(t); 746 ((register_t *)addr)[1] = process_get_pacmask(t); 747 return 0; 748 #endif 749 default: 750 KASSERTMSG(0, "%s: unhandled request %d", __func__, req); 751 break; 752 } 753 754 return 0; 755 } 756 757 758 /* 759 * Helper for doing "it could be a PID or TID" lookup. On failure 760 * returns NULL; on success returns the selected process and sets *tp 761 * to an appropriate thread in that process. 762 */ 763 static inline struct process * 764 process_tprfind(pid_t tpid, struct proc **tp) 765 { 766 if (tpid > THREAD_PID_OFFSET) { 767 struct proc *t = tfind(tpid - THREAD_PID_OFFSET); 768 769 if (t == NULL) 770 return NULL; 771 *tp = t; 772 return t->p_p; 773 } else { 774 struct process *tr = prfind(tpid); 775 776 if (tr == NULL) 777 return NULL; 778 *tp = TAILQ_FIRST(&tr->ps_threads); 779 return tr; 780 } 781 } 782 783 784 /* 785 * Check whether 'tr' is currently traced by 'curpr' and in a state 786 * to be manipulated. If 't' is supplied then it must be stopped and 787 * waited for. 788 */ 789 static inline int 790 process_checktracestate(struct process *curpr, struct process *tr, 791 struct proc *t) 792 { 793 /* 794 * You can't do what you want to the process if: 795 * (1) It's not being traced at all, 796 */ 797 if (!ISSET(tr->ps_flags, PS_TRACED)) 798 return EPERM; 799 800 /* 801 * (2) it's not being traced by _you_, or 802 */ 803 if (tr->ps_pptr != curpr) 804 return EBUSY; 805 806 /* 807 * (3) it's in the middle of execve(2) 808 */ 809 if (ISSET(tr->ps_flags, PS_INEXEC)) 810 return EAGAIN; 811 812 /* 813 * (4) if a thread was specified and it's not currently stopped. 814 */ 815 if (t != NULL && 816 (t->p_stat != SSTOP || !ISSET(tr->ps_flags, PS_WAITED))) 817 return EBUSY; 818 819 return 0; 820 } 821 822 #endif /* PTRACE */ 823 824 /* 825 * Check if a process is allowed to fiddle with the memory of another. 826 * 827 * p = tracer 828 * tr = tracee 829 * 830 * 1. You can't attach to a process not owned by you or one that has raised 831 * its privileges. 832 * 1a. ...unless you are root. 833 * 834 * 2. init is always off-limits because it can control the securelevel. 835 * 2a. ...unless securelevel is permanently set to insecure. 836 * 837 * 3. Processes that are in the process of doing an exec() are always 838 * off-limits because of the can of worms they are. Just wait a 839 * second. 840 */ 841 int 842 process_checkioperm(struct proc *p, struct process *tr) 843 { 844 int error; 845 846 if ((tr->ps_ucred->cr_ruid != p->p_ucred->cr_ruid || 847 ISSET(tr->ps_flags, PS_SUGIDEXEC | PS_SUGID)) && 848 (error = suser(p)) != 0) 849 return (error); 850 851 if ((tr->ps_pid == 1) && (securelevel > -1)) 852 return (EPERM); 853 854 if (ISSET(tr->ps_flags, PS_INEXEC)) 855 return (EAGAIN); 856 857 return (0); 858 } 859 860 int 861 process_domem(struct proc *curp, struct process *tr, struct uio *uio, int req) 862 { 863 struct vmspace *vm; 864 int error; 865 vaddr_t addr; 866 vsize_t len; 867 868 len = uio->uio_resid; 869 if (len == 0) 870 return 0; 871 872 if ((error = process_checkioperm(curp, tr)) != 0) 873 return error; 874 875 vm = tr->ps_vmspace; 876 if ((tr->ps_flags & PS_EXITING) || (vm->vm_refcnt < 1)) 877 return EFAULT; 878 addr = uio->uio_offset; 879 880 uvmspace_addref(vm); 881 882 error = uvm_io(&vm->vm_map, uio, UVM_IO_FIXPROT); 883 884 uvmspace_free(vm); 885 886 if (error == 0 && req == PT_WRITE_I) 887 pmap_proc_iflush(tr, addr, len); 888 889 return error; 890 } 891