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 * $FreeBSD: src/sys/kern/sys_process.c,v 1.51.2.6 2003/01/08 03:06:45 kan Exp $ 32 * $DragonFly: src/sys/kern/sys_process.c,v 1.30 2007/02/19 01:14:23 corecode Exp $ 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/sysproto.h> 38 #include <sys/proc.h> 39 #include <sys/priv.h> 40 #include <sys/vnode.h> 41 #include <sys/ptrace.h> 42 #include <sys/reg.h> 43 #include <sys/lock.h> 44 45 #include <vm/vm.h> 46 #include <vm/pmap.h> 47 #include <vm/vm_map.h> 48 #include <vm/vm_page.h> 49 50 #include <sys/user.h> 51 #include <vfs/procfs/procfs.h> 52 53 #include <sys/thread2.h> 54 #include <sys/spinlock2.h> 55 56 /* use the equivalent procfs code */ 57 #if 0 58 static int 59 pread (struct proc *procp, unsigned int addr, unsigned int *retval) { 60 int rv; 61 vm_map_t map, tmap; 62 vm_object_t object; 63 vm_offset_t kva = 0; 64 int page_offset; /* offset into page */ 65 vm_offset_t pageno; /* page number */ 66 vm_map_entry_t out_entry; 67 vm_prot_t out_prot; 68 boolean_t wired; 69 vm_pindex_t pindex; 70 71 /* Map page into kernel space */ 72 73 map = &procp->p_vmspace->vm_map; 74 75 page_offset = addr - trunc_page(addr); 76 pageno = trunc_page(addr); 77 78 tmap = map; 79 rv = vm_map_lookup (&tmap, pageno, VM_PROT_READ, &out_entry, 80 &object, &pindex, &out_prot, &wired); 81 82 if (rv != KERN_SUCCESS) 83 return EINVAL; 84 85 vm_map_lookup_done (tmap, out_entry, 0); 86 87 /* Find space in kernel_map for the page we're interested in */ 88 rv = vm_map_find (&kernel_map, object, IDX_TO_OFF(pindex), 89 &kva, 90 PAGE_SIZE, PAGE_SIZE, 91 0, VM_MAPTYPE_NORMAL, 92 VM_PROT_ALL, VM_PROT_ALL, 93 0); 94 95 if (!rv) { 96 vm_object_reference (object); 97 98 rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0); 99 if (!rv) { 100 *retval = 0; 101 bcopy ((caddr_t)kva + page_offset, 102 retval, sizeof *retval); 103 } 104 vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE); 105 } 106 107 return rv; 108 } 109 110 static int 111 pwrite (struct proc *procp, unsigned int addr, unsigned int datum) { 112 int rv; 113 vm_map_t map, tmap; 114 vm_object_t object; 115 vm_offset_t kva = 0; 116 int page_offset; /* offset into page */ 117 vm_offset_t pageno; /* page number */ 118 vm_map_entry_t out_entry; 119 vm_prot_t out_prot; 120 boolean_t wired; 121 vm_pindex_t pindex; 122 boolean_t fix_prot = 0; 123 124 /* Map page into kernel space */ 125 126 map = &procp->p_vmspace->vm_map; 127 128 page_offset = addr - trunc_page(addr); 129 pageno = trunc_page(addr); 130 131 /* 132 * Check the permissions for the area we're interested in. 133 */ 134 135 if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE, 136 VM_PROT_WRITE, FALSE) == FALSE) { 137 /* 138 * If the page was not writable, we make it so. 139 * XXX It is possible a page may *not* be read/executable, 140 * if a process changes that! 141 */ 142 fix_prot = 1; 143 /* The page isn't writable, so let's try making it so... */ 144 if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE, 145 VM_PROT_ALL, 0)) != KERN_SUCCESS) 146 return EFAULT; /* I guess... */ 147 } 148 149 /* 150 * Now we need to get the page. out_entry, out_prot, wired, and 151 * single_use aren't used. One would think the vm code would be 152 * a *bit* nicer... We use tmap because vm_map_lookup() can 153 * change the map argument. 154 */ 155 156 tmap = map; 157 rv = vm_map_lookup (&tmap, pageno, VM_PROT_WRITE, &out_entry, 158 &object, &pindex, &out_prot, &wired); 159 if (rv != KERN_SUCCESS) { 160 return EINVAL; 161 } 162 163 /* 164 * Okay, we've got the page. Let's release tmap. 165 */ 166 167 vm_map_lookup_done (tmap, out_entry, 0); 168 169 /* 170 * Fault the page in... 171 */ 172 173 rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE); 174 if (rv != KERN_SUCCESS) 175 return EFAULT; 176 177 /* Find space in kernel_map for the page we're interested in */ 178 rv = vm_map_find (&kernel_map, object, IDX_TO_OFF(pindex), 179 &kva, 180 PAGE_SIZE, PAGE_SIZE, 181 0, VM_MAPTYPE_NORMAL, 182 VM_PROT_ALL, VM_PROT_ALL, 183 0); 184 if (!rv) { 185 vm_object_reference (object); 186 187 rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0); 188 if (!rv) { 189 bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum); 190 } 191 vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE); 192 } 193 194 if (fix_prot) 195 vm_map_protect (map, pageno, pageno + PAGE_SIZE, 196 VM_PROT_READ|VM_PROT_EXECUTE, 0); 197 return rv; 198 } 199 #endif 200 201 /* 202 * Process debugging system call. 203 * 204 * MPALMOSTSAFE 205 */ 206 int 207 sys_ptrace(struct ptrace_args *uap) 208 { 209 struct proc *p = curproc; 210 211 /* 212 * XXX this obfuscation is to reduce stack usage, but the register 213 * structs may be too large to put on the stack anyway. 214 */ 215 union { 216 struct ptrace_io_desc piod; 217 struct dbreg dbreg; 218 struct fpreg fpreg; 219 struct reg reg; 220 } r; 221 void *addr; 222 int error = 0; 223 224 addr = &r; 225 switch (uap->req) { 226 case PT_GETREGS: 227 case PT_GETFPREGS: 228 #ifdef PT_GETDBREGS 229 case PT_GETDBREGS: 230 #endif 231 break; 232 case PT_SETREGS: 233 error = copyin(uap->addr, &r.reg, sizeof r.reg); 234 break; 235 case PT_SETFPREGS: 236 error = copyin(uap->addr, &r.fpreg, sizeof r.fpreg); 237 break; 238 #ifdef PT_SETDBREGS 239 case PT_SETDBREGS: 240 error = copyin(uap->addr, &r.dbreg, sizeof r.dbreg); 241 break; 242 #endif 243 case PT_IO: 244 error = copyin(uap->addr, &r.piod, sizeof r.piod); 245 break; 246 default: 247 addr = uap->addr; 248 } 249 if (error) 250 return (error); 251 252 error = kern_ptrace(p, uap->req, uap->pid, addr, uap->data, 253 &uap->sysmsg_result); 254 if (error) 255 return (error); 256 257 switch (uap->req) { 258 case PT_IO: 259 (void)copyout(&r.piod, uap->addr, sizeof r.piod); 260 break; 261 case PT_GETREGS: 262 error = copyout(&r.reg, uap->addr, sizeof r.reg); 263 break; 264 case PT_GETFPREGS: 265 error = copyout(&r.fpreg, uap->addr, sizeof r.fpreg); 266 break; 267 #ifdef PT_GETDBREGS 268 case PT_GETDBREGS: 269 error = copyout(&r.dbreg, uap->addr, sizeof r.dbreg); 270 break; 271 #endif 272 } 273 274 return (error); 275 } 276 277 int 278 kern_ptrace(struct proc *curp, int req, pid_t pid, void *addr, 279 int data, int *res) 280 { 281 struct proc *p, *pp; 282 struct lwp *lp; 283 struct iovec iov; 284 struct uio uio; 285 struct ptrace_io_desc *piod; 286 int error = 0; 287 int write, tmp; 288 int t; 289 290 lwkt_gettoken(&proc_token); 291 292 write = 0; 293 if (req == PT_TRACE_ME) { 294 p = curp; 295 PHOLD(p); 296 } else { 297 if ((p = pfind(pid)) == NULL) { 298 lwkt_reltoken(&proc_token); 299 return ESRCH; 300 } 301 } 302 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) { 303 PRELE(p); 304 lwkt_reltoken(&proc_token); 305 return (ESRCH); 306 } 307 308 lwkt_gettoken(&p->p_token); 309 /* Can't trace a process that's currently exec'ing. */ 310 if ((p->p_flag & P_INEXEC) != 0) { 311 lwkt_reltoken(&p->p_token); 312 PRELE(p); 313 lwkt_reltoken(&proc_token); 314 return EAGAIN; 315 } 316 317 /* 318 * Permissions check 319 */ 320 switch (req) { 321 case PT_TRACE_ME: 322 /* Always legal. */ 323 break; 324 325 case PT_ATTACH: 326 /* Self */ 327 if (p->p_pid == curp->p_pid) { 328 lwkt_reltoken(&p->p_token); 329 PRELE(p); 330 lwkt_reltoken(&proc_token); 331 return EINVAL; 332 } 333 334 /* Already traced */ 335 if (p->p_flag & P_TRACED) { 336 lwkt_reltoken(&p->p_token); 337 PRELE(p); 338 lwkt_reltoken(&proc_token); 339 return EBUSY; 340 } 341 342 if (curp->p_flag & P_TRACED) 343 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) 344 if (pp == p) { 345 lwkt_reltoken(&p->p_token); 346 PRELE(p); 347 lwkt_reltoken(&proc_token); 348 return (EINVAL); 349 } 350 351 /* not owned by you, has done setuid (unless you're root) */ 352 if ((p->p_ucred->cr_ruid != curp->p_ucred->cr_ruid) || 353 (p->p_flag & P_SUGID)) { 354 if ((error = priv_check_cred(curp->p_ucred, PRIV_ROOT, 0)) != 0) { 355 lwkt_reltoken(&p->p_token); 356 PRELE(p); 357 lwkt_reltoken(&proc_token); 358 return error; 359 } 360 } 361 362 /* can't trace init when securelevel > 0 */ 363 if (securelevel > 0 && p->p_pid == 1) { 364 lwkt_reltoken(&p->p_token); 365 PRELE(p); 366 lwkt_reltoken(&proc_token); 367 return EPERM; 368 } 369 370 /* OK */ 371 break; 372 373 case PT_READ_I: 374 case PT_READ_D: 375 case PT_WRITE_I: 376 case PT_WRITE_D: 377 case PT_IO: 378 case PT_CONTINUE: 379 case PT_KILL: 380 case PT_STEP: 381 case PT_DETACH: 382 #ifdef PT_GETREGS 383 case PT_GETREGS: 384 #endif 385 #ifdef PT_SETREGS 386 case PT_SETREGS: 387 #endif 388 #ifdef PT_GETFPREGS 389 case PT_GETFPREGS: 390 #endif 391 #ifdef PT_SETFPREGS 392 case PT_SETFPREGS: 393 #endif 394 #ifdef PT_GETDBREGS 395 case PT_GETDBREGS: 396 #endif 397 #ifdef PT_SETDBREGS 398 case PT_SETDBREGS: 399 #endif 400 /* not being traced... */ 401 if ((p->p_flag & P_TRACED) == 0) { 402 lwkt_reltoken(&p->p_token); 403 PRELE(p); 404 lwkt_reltoken(&proc_token); 405 return EPERM; 406 } 407 408 /* not being traced by YOU */ 409 if (p->p_pptr != curp) { 410 lwkt_reltoken(&p->p_token); 411 PRELE(p); 412 lwkt_reltoken(&proc_token); 413 return EBUSY; 414 } 415 416 /* not currently stopped */ 417 if (p->p_stat != SSTOP || 418 (p->p_flag & P_WAITED) == 0) { 419 lwkt_reltoken(&p->p_token); 420 PRELE(p); 421 lwkt_reltoken(&proc_token); 422 return EBUSY; 423 } 424 425 /* OK */ 426 break; 427 428 default: 429 lwkt_reltoken(&p->p_token); 430 PRELE(p); 431 lwkt_reltoken(&proc_token); 432 return EINVAL; 433 } 434 435 /* XXX lwp */ 436 lp = FIRST_LWP_IN_PROC(p); 437 #ifdef FIX_SSTEP 438 /* 439 * Single step fixup ala procfs 440 */ 441 FIX_SSTEP(lp); 442 #endif 443 444 /* 445 * Actually do the requests 446 */ 447 448 *res = 0; 449 450 switch (req) { 451 case PT_TRACE_ME: 452 /* set my trace flag and "owner" so it can read/write me */ 453 p->p_flag |= P_TRACED; 454 p->p_oppid = p->p_pptr->p_pid; 455 lwkt_reltoken(&p->p_token); 456 PRELE(p); 457 lwkt_reltoken(&proc_token); 458 return 0; 459 460 case PT_ATTACH: 461 /* security check done above */ 462 p->p_flag |= P_TRACED; 463 p->p_oppid = p->p_pptr->p_pid; 464 if (p->p_pptr != curp) 465 proc_reparent(p, curp); 466 data = SIGSTOP; 467 goto sendsig; /* in PT_CONTINUE below */ 468 469 case PT_STEP: 470 case PT_CONTINUE: 471 case PT_DETACH: 472 /* Zero means do not send any signal */ 473 if (data < 0 || data > _SIG_MAXSIG) { 474 lwkt_reltoken(&p->p_token); 475 PRELE(p); 476 lwkt_reltoken(&proc_token); 477 return EINVAL; 478 } 479 480 LWPHOLD(lp); 481 482 if (req == PT_STEP) { 483 if ((error = ptrace_single_step (lp))) { 484 LWPRELE(lp); 485 lwkt_reltoken(&p->p_token); 486 PRELE(p); 487 lwkt_reltoken(&proc_token); 488 return error; 489 } 490 } 491 492 if (addr != (void *)1) { 493 if ((error = ptrace_set_pc (lp, 494 (u_long)(uintfptr_t)addr))) { 495 LWPRELE(lp); 496 lwkt_reltoken(&p->p_token); 497 PRELE(p); 498 lwkt_reltoken(&proc_token); 499 return error; 500 } 501 } 502 LWPRELE(lp); 503 504 if (req == PT_DETACH) { 505 /* reset process parent */ 506 if (p->p_oppid != p->p_pptr->p_pid) { 507 struct proc *pp; 508 509 pp = pfind(p->p_oppid); 510 proc_reparent(p, pp ? pp : initproc); 511 } 512 513 p->p_flag &= ~(P_TRACED | P_WAITED); 514 p->p_oppid = 0; 515 516 /* should we send SIGCHLD? */ 517 } 518 519 sendsig: 520 /* 521 * Deliver or queue signal. If the process is stopped 522 * force it to be SACTIVE again. 523 */ 524 crit_enter(); 525 if (p->p_stat == SSTOP) { 526 p->p_xstat = data; 527 lp->lwp_flag |= LWP_BREAKTSLEEP; 528 proc_unstop(p); 529 } else if (data) { 530 ksignal(p, data); 531 } 532 crit_exit(); 533 lwkt_reltoken(&p->p_token); 534 PRELE(p); 535 lwkt_reltoken(&proc_token); 536 return 0; 537 538 case PT_WRITE_I: 539 case PT_WRITE_D: 540 write = 1; 541 /* fallthrough */ 542 case PT_READ_I: 543 case PT_READ_D: 544 /* 545 * NOTE! uio_offset represents the offset in the target 546 * process. The iov is in the current process (the guy 547 * making the ptrace call) so uio_td must be the current 548 * process (though for a SYSSPACE transfer it doesn't 549 * really matter). 550 */ 551 tmp = 0; 552 /* write = 0 set above */ 553 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; 554 iov.iov_len = sizeof(int); 555 uio.uio_iov = &iov; 556 uio.uio_iovcnt = 1; 557 uio.uio_offset = (off_t)(uintptr_t)addr; 558 uio.uio_resid = sizeof(int); 559 uio.uio_segflg = UIO_SYSSPACE; 560 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 561 uio.uio_td = curthread; 562 error = procfs_domem(curp, lp, NULL, &uio); 563 if (uio.uio_resid != 0) { 564 /* 565 * XXX procfs_domem() doesn't currently return ENOSPC, 566 * so I think write() can bogusly return 0. 567 * XXX what happens for short writes? We don't want 568 * to write partial data. 569 * XXX procfs_domem() returns EPERM for other invalid 570 * addresses. Convert this to EINVAL. Does this 571 * clobber returns of EPERM for other reasons? 572 */ 573 if (error == 0 || error == ENOSPC || error == EPERM) 574 error = EINVAL; /* EOF */ 575 } 576 if (!write) 577 *res = tmp; 578 lwkt_reltoken(&p->p_token); 579 PRELE(p); 580 lwkt_reltoken(&proc_token); 581 return (error); 582 583 case PT_IO: 584 /* 585 * NOTE! uio_offset represents the offset in the target 586 * process. The iov is in the current process (the guy 587 * making the ptrace call) so uio_td must be the current 588 * process. 589 */ 590 piod = addr; 591 iov.iov_base = piod->piod_addr; 592 iov.iov_len = piod->piod_len; 593 uio.uio_iov = &iov; 594 uio.uio_iovcnt = 1; 595 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; 596 uio.uio_resid = piod->piod_len; 597 uio.uio_segflg = UIO_USERSPACE; 598 uio.uio_td = curthread; 599 switch (piod->piod_op) { 600 case PIOD_READ_D: 601 case PIOD_READ_I: 602 uio.uio_rw = UIO_READ; 603 break; 604 case PIOD_WRITE_D: 605 case PIOD_WRITE_I: 606 uio.uio_rw = UIO_WRITE; 607 break; 608 default: 609 lwkt_reltoken(&p->p_token); 610 PRELE(p); 611 lwkt_reltoken(&proc_token); 612 return (EINVAL); 613 } 614 error = procfs_domem(curp, lp, NULL, &uio); 615 piod->piod_len -= uio.uio_resid; 616 lwkt_reltoken(&p->p_token); 617 PRELE(p); 618 lwkt_reltoken(&proc_token); 619 return (error); 620 621 case PT_KILL: 622 data = SIGKILL; 623 goto sendsig; /* in PT_CONTINUE above */ 624 625 #ifdef PT_SETREGS 626 case PT_SETREGS: 627 write = 1; 628 /* fallthrough */ 629 #endif /* PT_SETREGS */ 630 #ifdef PT_GETREGS 631 case PT_GETREGS: 632 /* write = 0 above */ 633 #endif /* PT_SETREGS */ 634 #if defined(PT_SETREGS) || defined(PT_GETREGS) 635 if (!procfs_validregs(lp)) { /* no P_SYSTEM procs please */ 636 lwkt_reltoken(&p->p_token); 637 PRELE(p); 638 lwkt_reltoken(&proc_token); 639 return EINVAL; 640 } else { 641 iov.iov_base = addr; 642 iov.iov_len = sizeof(struct reg); 643 uio.uio_iov = &iov; 644 uio.uio_iovcnt = 1; 645 uio.uio_offset = 0; 646 uio.uio_resid = sizeof(struct reg); 647 uio.uio_segflg = UIO_SYSSPACE; 648 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 649 uio.uio_td = curthread; 650 t = procfs_doregs(curp, lp, NULL, &uio); 651 lwkt_reltoken(&p->p_token); 652 PRELE(p); 653 lwkt_reltoken(&proc_token); 654 return t; 655 } 656 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */ 657 658 #ifdef PT_SETFPREGS 659 case PT_SETFPREGS: 660 write = 1; 661 /* fallthrough */ 662 #endif /* PT_SETFPREGS */ 663 #ifdef PT_GETFPREGS 664 case PT_GETFPREGS: 665 /* write = 0 above */ 666 #endif /* PT_SETFPREGS */ 667 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) 668 if (!procfs_validfpregs(lp)) { /* no P_SYSTEM procs please */ 669 lwkt_reltoken(&p->p_token); 670 PRELE(p); 671 lwkt_reltoken(&proc_token); 672 return EINVAL; 673 } else { 674 iov.iov_base = addr; 675 iov.iov_len = sizeof(struct fpreg); 676 uio.uio_iov = &iov; 677 uio.uio_iovcnt = 1; 678 uio.uio_offset = 0; 679 uio.uio_resid = sizeof(struct fpreg); 680 uio.uio_segflg = UIO_SYSSPACE; 681 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 682 uio.uio_td = curthread; 683 t = procfs_dofpregs(curp, lp, NULL, &uio); 684 lwkt_reltoken(&p->p_token); 685 PRELE(p); 686 lwkt_reltoken(&proc_token); 687 return t; 688 } 689 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */ 690 691 #ifdef PT_SETDBREGS 692 case PT_SETDBREGS: 693 write = 1; 694 /* fallthrough */ 695 #endif /* PT_SETDBREGS */ 696 #ifdef PT_GETDBREGS 697 case PT_GETDBREGS: 698 /* write = 0 above */ 699 #endif /* PT_SETDBREGS */ 700 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS) 701 if (!procfs_validdbregs(lp)) { /* no P_SYSTEM procs please */ 702 lwkt_reltoken(&p->p_token); 703 PRELE(p); 704 lwkt_reltoken(&proc_token); 705 return EINVAL; 706 } else { 707 iov.iov_base = addr; 708 iov.iov_len = sizeof(struct dbreg); 709 uio.uio_iov = &iov; 710 uio.uio_iovcnt = 1; 711 uio.uio_offset = 0; 712 uio.uio_resid = sizeof(struct dbreg); 713 uio.uio_segflg = UIO_SYSSPACE; 714 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 715 uio.uio_td = curthread; 716 t = procfs_dodbregs(curp, lp, NULL, &uio); 717 lwkt_reltoken(&p->p_token); 718 PRELE(p); 719 lwkt_reltoken(&proc_token); 720 return t; 721 } 722 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */ 723 724 default: 725 break; 726 } 727 728 lwkt_reltoken(&p->p_token); 729 PRELE(p); 730 lwkt_reltoken(&proc_token); 731 732 return 0; 733 } 734 735 int 736 trace_req(struct proc *p) 737 { 738 return 1; 739 } 740 741 /* 742 * stopevent() 743 * 744 * Stop a process because of a procfs event. Stay stopped until p->p_step 745 * is cleared (cleared by PIOCCONT in procfs). 746 * 747 * MPSAFE 748 */ 749 void 750 stopevent(struct proc *p, unsigned int event, unsigned int val) 751 { 752 /* 753 * Set event info. Recheck p_stops in case we are 754 * racing a close() on procfs. 755 */ 756 spin_lock(&p->p_spin); 757 if ((p->p_stops & event) == 0) { 758 spin_unlock(&p->p_spin); 759 return; 760 } 761 p->p_xstat = val; 762 p->p_stype = event; 763 p->p_step = 1; 764 tsleep_interlock(&p->p_step, 0); 765 spin_unlock(&p->p_spin); 766 767 /* 768 * Wakeup any PIOCWAITing procs and wait for p_step to 769 * be cleared. 770 */ 771 for (;;) { 772 wakeup(&p->p_stype); 773 tsleep(&p->p_step, PINTERLOCKED, "stopevent", 0); 774 spin_lock(&p->p_spin); 775 if (p->p_step == 0) { 776 spin_unlock(&p->p_spin); 777 break; 778 } 779 tsleep_interlock(&p->p_step, 0); 780 spin_unlock(&p->p_spin); 781 } 782 } 783 784