1 /* $OpenBSD: sys_process.c,v 1.91 2022/12/21 07:59:02 claudio 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 } u; 108 int size = 0; 109 enum { NONE, IN, IN_ALLOC, OUT, OUT_ALLOC, IN_OUT } mode; 110 int kstate = 0; 111 int error; 112 113 *retval = 0; 114 115 /* Figure out what sort of copyin/out operations we'll do */ 116 switch (req) { 117 case PT_TRACE_ME: 118 case PT_CONTINUE: 119 case PT_KILL: 120 case PT_ATTACH: 121 case PT_DETACH: 122 #ifdef PT_STEP 123 case PT_STEP: 124 #endif 125 /* control operations do no copyin/out; dispatch directly */ 126 return ptrace_ctrl(p, req, pid, uaddr, data); 127 128 case PT_READ_I: 129 case PT_READ_D: 130 case PT_WRITE_I: 131 case PT_WRITE_D: 132 mode = NONE; 133 break; 134 case PT_IO: 135 mode = IN_OUT; 136 size = sizeof u.u_piod; 137 data = size; /* suppress the data == size check */ 138 break; 139 case PT_GET_THREAD_FIRST: 140 mode = OUT; 141 size = sizeof u.u_pts; 142 kstate = 1; 143 break; 144 case PT_GET_THREAD_NEXT: 145 mode = IN_OUT; 146 size = sizeof u.u_pts; 147 kstate = 1; 148 break; 149 case PT_GET_EVENT_MASK: 150 mode = OUT; 151 size = sizeof u.u_pe; 152 kstate = 1; 153 break; 154 case PT_SET_EVENT_MASK: 155 mode = IN; 156 size = sizeof u.u_pe; 157 kstate = 1; 158 break; 159 case PT_GET_PROCESS_STATE: 160 mode = OUT; 161 size = sizeof u.u_ps; 162 kstate = 1; 163 break; 164 case PT_GETREGS: 165 mode = OUT_ALLOC; 166 size = sizeof(struct reg); 167 break; 168 case PT_SETREGS: 169 mode = IN_ALLOC; 170 size = sizeof(struct reg); 171 break; 172 #ifdef PT_GETFPREGS 173 case PT_GETFPREGS: 174 mode = OUT_ALLOC; 175 size = sizeof(struct fpreg); 176 break; 177 #endif 178 #ifdef PT_SETFPREGS 179 case PT_SETFPREGS: 180 mode = IN_ALLOC; 181 size = sizeof(struct fpreg); 182 break; 183 #endif 184 #ifdef PT_GETXMMREGS 185 case PT_GETXMMREGS: 186 mode = OUT_ALLOC; 187 size = sizeof(struct xmmregs); 188 break; 189 #endif 190 #ifdef PT_SETXMMREGS 191 case PT_SETXMMREGS: 192 mode = IN_ALLOC; 193 size = sizeof(struct xmmregs); 194 break; 195 #endif 196 #ifdef PT_WCOOKIE 197 case PT_WCOOKIE: 198 mode = OUT; 199 size = sizeof u.u_wcookie; 200 data = size; /* suppress the data == size check */ 201 break; 202 #endif 203 default: 204 return EINVAL; 205 } 206 207 208 /* Now do any copyin()s and allocations in a consistent manner */ 209 switch (mode) { 210 case NONE: 211 kaddr = uaddr; 212 break; 213 case IN: 214 case IN_OUT: 215 case OUT: 216 KASSERT(size <= sizeof u); 217 if (data != size) 218 return EINVAL; 219 if (mode == OUT) 220 memset(&u, 0, size); 221 else { /* IN or IN_OUT */ 222 if ((error = copyin(uaddr, &u, size))) 223 return error; 224 } 225 kaddr = &u; 226 break; 227 case IN_ALLOC: 228 kaddr = malloc(size, M_TEMP, M_WAITOK); 229 if ((error = copyin(uaddr, kaddr, size))) { 230 free(kaddr, M_TEMP, size); 231 return error; 232 } 233 break; 234 case OUT_ALLOC: 235 kaddr = malloc(size, M_TEMP, M_WAITOK | M_ZERO); 236 break; 237 } 238 239 if (kstate) 240 error = ptrace_kstate(p, req, pid, kaddr); 241 else 242 error = ptrace_ustate(p, req, pid, kaddr, data, retval); 243 244 /* Do any copyout()s and frees */ 245 if (error == 0) { 246 switch (mode) { 247 case NONE: 248 case IN: 249 case IN_ALLOC: 250 break; 251 case IN_OUT: 252 case OUT: 253 error = copyout(&u, uaddr, size); 254 if (req == PT_IO) { 255 /* historically, errors here are ignored */ 256 error = 0; 257 } 258 break; 259 case OUT_ALLOC: 260 error = copyout(kaddr, uaddr, size); 261 break; 262 } 263 } 264 265 if (mode == IN_ALLOC || mode == OUT_ALLOC) 266 free(kaddr, M_TEMP, size); 267 return error; 268 } 269 270 /* 271 * ptrace control requests: attach, detach, continue, kill, single-step, etc 272 */ 273 int 274 ptrace_ctrl(struct proc *p, int req, pid_t pid, caddr_t addr, int data) 275 { 276 struct proc *t; /* target thread */ 277 struct process *tr; /* target process */ 278 int error = 0; 279 int s; 280 281 switch (req) { 282 case PT_TRACE_ME: 283 /* Just set the trace flag. */ 284 tr = p->p_p; 285 if (ISSET(tr->ps_flags, PS_TRACED)) 286 return EBUSY; 287 atomic_setbits_int(&tr->ps_flags, PS_TRACED); 288 tr->ps_oppid = tr->ps_pptr->ps_pid; 289 if (tr->ps_ptstat == NULL) 290 tr->ps_ptstat = malloc(sizeof(*tr->ps_ptstat), 291 M_SUBPROC, M_WAITOK); 292 memset(tr->ps_ptstat, 0, sizeof(*tr->ps_ptstat)); 293 return 0; 294 295 /* calls that only operate on the PID */ 296 case PT_KILL: 297 case PT_ATTACH: 298 case PT_DETACH: 299 /* Find the process we're supposed to be operating on. */ 300 if ((tr = prfind(pid)) == NULL) { 301 error = ESRCH; 302 goto fail; 303 } 304 t = TAILQ_FIRST(&tr->ps_threads); 305 break; 306 307 /* calls that accept a PID or a thread ID */ 308 case PT_CONTINUE: 309 #ifdef PT_STEP 310 case PT_STEP: 311 #endif 312 if ((tr = process_tprfind(pid, &t)) == NULL) { 313 error = ESRCH; 314 goto fail; 315 } 316 break; 317 } 318 319 /* Check permissions/state */ 320 if (req != PT_ATTACH) { 321 /* Check that the data is a valid signal number or zero. */ 322 if (req != PT_KILL && (data < 0 || data >= NSIG)) { 323 error = EINVAL; 324 goto fail; 325 } 326 327 /* Most operations require the target to already be traced */ 328 if ((error = process_checktracestate(p->p_p, tr, t))) 329 goto fail; 330 331 /* Do single-step fixup if needed. */ 332 FIX_SSTEP(t); 333 } else { 334 /* 335 * PT_ATTACH is the opposite; you can't attach to a process if: 336 * (1) it's the process that's doing the attaching, 337 */ 338 if (tr == p->p_p) { 339 error = EINVAL; 340 goto fail; 341 } 342 343 /* 344 * (2) it's a system process 345 */ 346 if (ISSET(tr->ps_flags, PS_SYSTEM)) { 347 error = EPERM; 348 goto fail; 349 } 350 351 /* 352 * (3) it's already being traced, or 353 */ 354 if (ISSET(tr->ps_flags, PS_TRACED)) { 355 error = EBUSY; 356 goto fail; 357 } 358 359 /* 360 * (4) it's in the middle of execve(2) 361 */ 362 if (ISSET(tr->ps_flags, PS_INEXEC)) { 363 error = EAGAIN; 364 goto fail; 365 } 366 367 /* 368 * (5) it's not owned by you, or the last exec 369 * gave us setuid/setgid privs (unless 370 * you're root), or... 371 * 372 * [Note: once PS_SUGID or PS_SUGIDEXEC gets set in 373 * execve(), they stay set until the process does 374 * another execve(). Hence this prevents a setuid 375 * process which revokes its special privileges using 376 * setuid() from being traced. This is good security.] 377 */ 378 if ((tr->ps_ucred->cr_ruid != p->p_ucred->cr_ruid || 379 ISSET(tr->ps_flags, PS_SUGIDEXEC | PS_SUGID)) && 380 (error = suser(p)) != 0) 381 goto fail; 382 383 /* 384 * (5.5) it's not a child of the tracing process. 385 */ 386 if (global_ptrace == 0 && !inferior(tr, p->p_p) && 387 (error = suser(p)) != 0) 388 goto fail; 389 390 /* 391 * (6) ...it's init, which controls the security level 392 * of the entire system, and the system was not 393 * compiled with permanently insecure mode turned 394 * on. 395 */ 396 if ((tr->ps_pid == 1) && (securelevel > -1)) { 397 error = EPERM; 398 goto fail; 399 } 400 401 /* 402 * (7) it's an ancestor of the current process and 403 * not init (because that would create a loop in 404 * the process graph). 405 */ 406 if (tr->ps_pid != 1 && inferior(p->p_p, tr)) { 407 error = EINVAL; 408 goto fail; 409 } 410 } 411 412 switch (req) { 413 414 #ifdef PT_STEP 415 case PT_STEP: 416 /* 417 * From the 4.4BSD PRM: 418 * "Execution continues as in request PT_CONTINUE; however 419 * as soon as possible after execution of at least one 420 * instruction, execution stops again. [ ... ]" 421 */ 422 #endif 423 case PT_CONTINUE: 424 /* 425 * From the 4.4BSD PRM: 426 * "The data argument is taken as a signal number and the 427 * child's execution continues at location addr as if it 428 * incurred that signal. Normally the signal number will 429 * be either 0 to indicate that the signal that caused the 430 * stop should be ignored, or that value fetched out of 431 * the process's image indicating which signal caused 432 * the stop. If addr is (int *)1 then execution continues 433 * from where it stopped." 434 */ 435 436 if (pid < THREAD_PID_OFFSET && tr->ps_single) 437 t = tr->ps_single; 438 439 /* If the address parameter is not (int *)1, set the pc. */ 440 if ((int *)addr != (int *)1) 441 if ((error = process_set_pc(t, addr)) != 0) 442 goto fail; 443 444 #ifdef PT_STEP 445 /* 446 * Arrange for a single-step, if that's requested and possible. 447 */ 448 error = process_sstep(t, req == PT_STEP); 449 if (error) 450 goto fail; 451 #endif 452 goto sendsig; 453 454 case PT_DETACH: 455 /* 456 * From the 4.4BSD PRM: 457 * "The data argument is taken as a signal number and the 458 * child's execution continues at location addr as if it 459 * incurred that signal. Normally the signal number will 460 * be either 0 to indicate that the signal that caused the 461 * stop should be ignored, or that value fetched out of 462 * the process's image indicating which signal caused 463 * the stop. If addr is (int *)1 then execution continues 464 * from where it stopped." 465 */ 466 467 if (pid < THREAD_PID_OFFSET && tr->ps_single) 468 t = tr->ps_single; 469 470 #ifdef PT_STEP 471 /* 472 * Stop single stepping. 473 */ 474 error = process_sstep(t, 0); 475 if (error) 476 goto fail; 477 #endif 478 479 process_untrace(tr); 480 atomic_clearbits_int(&tr->ps_flags, PS_WAITED); 481 482 sendsig: 483 memset(tr->ps_ptstat, 0, sizeof(*tr->ps_ptstat)); 484 485 /* Finally, deliver the requested signal (or none). */ 486 if (t->p_stat == SSTOP) { 487 tr->ps_xsig = data; 488 SCHED_LOCK(s); 489 setrunnable(t); 490 SCHED_UNLOCK(s); 491 } else { 492 if (data != 0) 493 psignal(t, data); 494 } 495 break; 496 497 case PT_KILL: 498 if (pid < THREAD_PID_OFFSET && tr->ps_single) 499 t = tr->ps_single; 500 501 /* just send the process a KILL signal. */ 502 data = SIGKILL; 503 goto sendsig; /* in PT_CONTINUE, above. */ 504 505 case PT_ATTACH: 506 /* 507 * As was done in procfs: 508 * Go ahead and set the trace flag. 509 * Save the old parent (it's reset in 510 * _DETACH, and also in kern_exit.c:wait4() 511 * Reparent the process so that the tracing 512 * proc gets to see all the action. 513 * Stop the target. 514 */ 515 atomic_setbits_int(&tr->ps_flags, PS_TRACED); 516 tr->ps_oppid = tr->ps_pptr->ps_pid; 517 process_reparent(tr, p->p_p); 518 if (tr->ps_ptstat == NULL) 519 tr->ps_ptstat = malloc(sizeof(*tr->ps_ptstat), 520 M_SUBPROC, M_WAITOK); 521 data = SIGSTOP; 522 goto sendsig; 523 default: 524 KASSERTMSG(0, "%s: unhandled request %d", __func__, req); 525 break; 526 } 527 528 fail: 529 return error; 530 } 531 532 /* 533 * ptrace kernel-state requests: thread list, event mask, process state 534 */ 535 int 536 ptrace_kstate(struct proc *p, int req, pid_t pid, void *addr) 537 { 538 struct process *tr; /* target process */ 539 struct ptrace_event *pe = addr; 540 int error; 541 542 KASSERT((p->p_flag & P_SYSTEM) == 0); 543 544 /* Find the process we're supposed to be operating on. */ 545 if ((tr = prfind(pid)) == NULL) 546 return ESRCH; 547 548 if ((error = process_checktracestate(p->p_p, tr, NULL))) 549 return error; 550 551 switch (req) { 552 case PT_GET_THREAD_FIRST: 553 case PT_GET_THREAD_NEXT: 554 { 555 struct ptrace_thread_state *pts = addr; 556 struct proc *t; 557 558 if (req == PT_GET_THREAD_NEXT) { 559 t = tfind(pts->pts_tid - THREAD_PID_OFFSET); 560 if (t == NULL || ISSET(t->p_flag, P_WEXIT)) 561 return ESRCH; 562 if (t->p_p != tr) 563 return EINVAL; 564 t = TAILQ_NEXT(t, p_thr_link); 565 } else { 566 t = TAILQ_FIRST(&tr->ps_threads); 567 } 568 569 if (t == NULL) 570 pts->pts_tid = -1; 571 else 572 pts->pts_tid = t->p_tid + THREAD_PID_OFFSET; 573 return 0; 574 } 575 } 576 577 switch (req) { 578 case PT_GET_EVENT_MASK: 579 pe->pe_set_event = tr->ps_ptmask; 580 break; 581 case PT_SET_EVENT_MASK: 582 tr->ps_ptmask = pe->pe_set_event; 583 break; 584 case PT_GET_PROCESS_STATE: 585 if (tr->ps_single) 586 tr->ps_ptstat->pe_tid = 587 tr->ps_single->p_tid + THREAD_PID_OFFSET; 588 memcpy(addr, tr->ps_ptstat, sizeof *tr->ps_ptstat); 589 break; 590 default: 591 KASSERTMSG(0, "%s: unhandled request %d", __func__, req); 592 break; 593 } 594 595 return 0; 596 } 597 598 /* 599 * ptrace user-state requests: memory access, registers, stack cookie 600 */ 601 int 602 ptrace_ustate(struct proc *p, int req, pid_t pid, void *addr, int data, 603 register_t *retval) 604 { 605 struct proc *t; /* target thread */ 606 struct process *tr; /* target process */ 607 struct uio uio; 608 struct iovec iov; 609 int error, write; 610 int temp = 0; 611 612 KASSERT((p->p_flag & P_SYSTEM) == 0); 613 614 /* Accept either PID or TID */ 615 if ((tr = process_tprfind(pid, &t)) == NULL) 616 return ESRCH; 617 618 if ((error = process_checktracestate(p->p_p, tr, t))) 619 return error; 620 621 FIX_SSTEP(t); 622 623 /* Now do the operation. */ 624 write = 0; 625 626 if ((error = process_checkioperm(p, tr)) != 0) 627 return error; 628 629 switch (req) { 630 case PT_WRITE_I: /* XXX no separate I and D spaces */ 631 case PT_WRITE_D: 632 write = 1; 633 temp = data; 634 case PT_READ_I: /* XXX no separate I and D spaces */ 635 case PT_READ_D: 636 /* write = 0 done above. */ 637 iov.iov_base = (caddr_t)&temp; 638 iov.iov_len = sizeof(int); 639 uio.uio_iov = &iov; 640 uio.uio_iovcnt = 1; 641 uio.uio_offset = (off_t)(vaddr_t)addr; 642 uio.uio_resid = sizeof(int); 643 uio.uio_segflg = UIO_SYSSPACE; 644 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 645 uio.uio_procp = p; 646 error = process_domem(p, tr, &uio, write ? PT_WRITE_I : 647 PT_READ_I); 648 if (write == 0) 649 *retval = temp; 650 return error; 651 652 case PT_IO: 653 { 654 struct ptrace_io_desc *piod = addr; 655 656 iov.iov_base = piod->piod_addr; 657 iov.iov_len = piod->piod_len; 658 uio.uio_iov = &iov; 659 uio.uio_iovcnt = 1; 660 uio.uio_offset = (off_t)(vaddr_t)piod->piod_offs; 661 uio.uio_resid = piod->piod_len; 662 uio.uio_segflg = UIO_USERSPACE; 663 uio.uio_procp = p; 664 switch (piod->piod_op) { 665 case PIOD_READ_I: 666 req = PT_READ_I; 667 uio.uio_rw = UIO_READ; 668 break; 669 case PIOD_READ_D: 670 req = PT_READ_D; 671 uio.uio_rw = UIO_READ; 672 break; 673 case PIOD_WRITE_I: 674 req = PT_WRITE_I; 675 uio.uio_rw = UIO_WRITE; 676 break; 677 case PIOD_WRITE_D: 678 req = PT_WRITE_D; 679 uio.uio_rw = UIO_WRITE; 680 break; 681 case PIOD_READ_AUXV: 682 req = PT_READ_D; 683 uio.uio_rw = UIO_READ; 684 temp = ELF_AUX_WORDS * sizeof(char *); 685 if (uio.uio_offset > temp) 686 return EIO; 687 if (uio.uio_resid > temp - uio.uio_offset) 688 uio.uio_resid = temp - uio.uio_offset; 689 piod->piod_len = iov.iov_len = uio.uio_resid; 690 uio.uio_offset += tr->ps_auxinfo; 691 #ifdef MACHINE_STACK_GROWS_UP 692 if (uio.uio_offset < (off_t)tr->ps_strings) 693 return EIO; 694 #else 695 if (uio.uio_offset > (off_t)tr->ps_strings) 696 return EIO; 697 if ((uio.uio_offset + uio.uio_resid) > 698 (off_t)tr->ps_strings) 699 uio.uio_resid = (off_t)tr->ps_strings - 700 uio.uio_offset; 701 #endif 702 break; 703 default: 704 return EINVAL; 705 } 706 error = process_domem(p, tr, &uio, req); 707 piod->piod_len -= uio.uio_resid; 708 return error; 709 } 710 711 case PT_SETREGS: 712 return process_write_regs(t, addr); 713 case PT_GETREGS: 714 return process_read_regs(t, addr); 715 716 #ifdef PT_SETFPREGS 717 case PT_SETFPREGS: 718 return process_write_fpregs(t, addr); 719 #endif 720 #ifdef PT_SETFPREGS 721 case PT_GETFPREGS: 722 return process_read_fpregs(t, addr); 723 #endif 724 #ifdef PT_SETXMMREGS 725 case PT_SETXMMREGS: 726 return process_write_xmmregs(t, addr); 727 #endif 728 #ifdef PT_SETXMMREGS 729 case PT_GETXMMREGS: 730 return process_read_xmmregs(t, addr); 731 #endif 732 #ifdef PT_WCOOKIE 733 case PT_WCOOKIE: 734 *(register_t *)addr = process_get_wcookie(t); 735 return 0; 736 #endif 737 default: 738 KASSERTMSG(0, "%s: unhandled request %d", __func__, req); 739 break; 740 } 741 742 return 0; 743 } 744 745 746 /* 747 * Helper for doing "it could be a PID or TID" lookup. On failure 748 * returns NULL; on success returns the selected process and sets *tp 749 * to an appropriate thread in that process. 750 */ 751 static inline struct process * 752 process_tprfind(pid_t tpid, struct proc **tp) 753 { 754 if (tpid > THREAD_PID_OFFSET) { 755 struct proc *t = tfind(tpid - THREAD_PID_OFFSET); 756 757 if (t == NULL) 758 return NULL; 759 *tp = t; 760 return t->p_p; 761 } else { 762 struct process *tr = prfind(tpid); 763 764 if (tr == NULL) 765 return NULL; 766 *tp = TAILQ_FIRST(&tr->ps_threads); 767 return tr; 768 } 769 } 770 771 772 /* 773 * Check whether 'tr' is currently traced by 'curpr' and in a state 774 * to be manipulated. If 't' is supplied then it must be stopped and 775 * waited for. 776 */ 777 static inline int 778 process_checktracestate(struct process *curpr, struct process *tr, 779 struct proc *t) 780 { 781 /* 782 * You can't do what you want to the process if: 783 * (1) It's not being traced at all, 784 */ 785 if (!ISSET(tr->ps_flags, PS_TRACED)) 786 return EPERM; 787 788 /* 789 * (2) it's not being traced by _you_, or 790 */ 791 if (tr->ps_pptr != curpr) 792 return EBUSY; 793 794 /* 795 * (3) it's in the middle of execve(2) 796 */ 797 if (ISSET(tr->ps_flags, PS_INEXEC)) 798 return EAGAIN; 799 800 /* 801 * (4) if a thread was specified and it's not currently stopped. 802 */ 803 if (t != NULL && 804 (t->p_stat != SSTOP || !ISSET(tr->ps_flags, PS_WAITED))) 805 return EBUSY; 806 807 return 0; 808 } 809 810 811 /* 812 * Check if a process is allowed to fiddle with the memory of another. 813 * 814 * p = tracer 815 * tr = tracee 816 * 817 * 1. You can't attach to a process not owned by you or one that has raised 818 * its privileges. 819 * 1a. ...unless you are root. 820 * 821 * 2. init is always off-limits because it can control the securelevel. 822 * 2a. ...unless securelevel is permanently set to insecure. 823 * 824 * 3. Processes that are in the process of doing an exec() are always 825 * off-limits because of the can of worms they are. Just wait a 826 * second. 827 */ 828 int 829 process_checkioperm(struct proc *p, struct process *tr) 830 { 831 int error; 832 833 if ((tr->ps_ucred->cr_ruid != p->p_ucred->cr_ruid || 834 ISSET(tr->ps_flags, PS_SUGIDEXEC | PS_SUGID)) && 835 (error = suser(p)) != 0) 836 return (error); 837 838 if ((tr->ps_pid == 1) && (securelevel > -1)) 839 return (EPERM); 840 841 if (ISSET(tr->ps_flags, PS_INEXEC)) 842 return (EAGAIN); 843 844 return (0); 845 } 846 847 int 848 process_domem(struct proc *curp, struct process *tr, struct uio *uio, int req) 849 { 850 struct vmspace *vm; 851 int error; 852 vaddr_t addr; 853 vsize_t len; 854 855 len = uio->uio_resid; 856 if (len == 0) 857 return 0; 858 859 if ((error = process_checkioperm(curp, tr)) != 0) 860 return error; 861 862 vm = tr->ps_vmspace; 863 if ((tr->ps_flags & PS_EXITING) || (vm->vm_refcnt < 1)) 864 return EFAULT; 865 addr = uio->uio_offset; 866 867 uvmspace_addref(vm); 868 869 error = uvm_io(&vm->vm_map, uio, 870 (uio->uio_rw == UIO_WRITE) ? UVM_IO_FIXPROT : 0); 871 872 uvmspace_free(vm); 873 874 if (error == 0 && req == PT_WRITE_I) 875 pmap_proc_iflush(tr, addr, len); 876 877 return error; 878 } 879 #endif 880