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 } else { 296 if ((p = pfind(pid)) == NULL) { 297 lwkt_reltoken(&proc_token); 298 return ESRCH; 299 } 300 } 301 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) { 302 lwkt_reltoken(&proc_token); 303 return (ESRCH); 304 } 305 306 lwkt_gettoken(&p->p_token); 307 /* Can't trace a process that's currently exec'ing. */ 308 if ((p->p_flag & P_INEXEC) != 0) { 309 lwkt_reltoken(&p->p_token); 310 lwkt_reltoken(&proc_token); 311 return EAGAIN; 312 } 313 314 /* 315 * Permissions check 316 */ 317 switch (req) { 318 case PT_TRACE_ME: 319 /* Always legal. */ 320 break; 321 322 case PT_ATTACH: 323 /* Self */ 324 if (p->p_pid == curp->p_pid) { 325 lwkt_reltoken(&p->p_token); 326 lwkt_reltoken(&proc_token); 327 return EINVAL; 328 } 329 330 /* Already traced */ 331 if (p->p_flag & P_TRACED) { 332 lwkt_reltoken(&p->p_token); 333 lwkt_reltoken(&proc_token); 334 return EBUSY; 335 } 336 337 if (curp->p_flag & P_TRACED) 338 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) 339 if (pp == p) { 340 lwkt_reltoken(&p->p_token); 341 lwkt_reltoken(&proc_token); 342 return (EINVAL); 343 } 344 345 /* not owned by you, has done setuid (unless you're root) */ 346 if ((p->p_ucred->cr_ruid != curp->p_ucred->cr_ruid) || 347 (p->p_flag & P_SUGID)) { 348 if ((error = priv_check_cred(curp->p_ucred, PRIV_ROOT, 0)) != 0) { 349 lwkt_reltoken(&p->p_token); 350 lwkt_reltoken(&proc_token); 351 return error; 352 } 353 } 354 355 /* can't trace init when securelevel > 0 */ 356 if (securelevel > 0 && p->p_pid == 1) { 357 lwkt_reltoken(&p->p_token); 358 lwkt_reltoken(&proc_token); 359 return EPERM; 360 } 361 362 /* OK */ 363 break; 364 365 case PT_READ_I: 366 case PT_READ_D: 367 case PT_WRITE_I: 368 case PT_WRITE_D: 369 case PT_IO: 370 case PT_CONTINUE: 371 case PT_KILL: 372 case PT_STEP: 373 case PT_DETACH: 374 #ifdef PT_GETREGS 375 case PT_GETREGS: 376 #endif 377 #ifdef PT_SETREGS 378 case PT_SETREGS: 379 #endif 380 #ifdef PT_GETFPREGS 381 case PT_GETFPREGS: 382 #endif 383 #ifdef PT_SETFPREGS 384 case PT_SETFPREGS: 385 #endif 386 #ifdef PT_GETDBREGS 387 case PT_GETDBREGS: 388 #endif 389 #ifdef PT_SETDBREGS 390 case PT_SETDBREGS: 391 #endif 392 /* not being traced... */ 393 if ((p->p_flag & P_TRACED) == 0) { 394 lwkt_reltoken(&p->p_token); 395 lwkt_reltoken(&proc_token); 396 return EPERM; 397 } 398 399 /* not being traced by YOU */ 400 if (p->p_pptr != curp) { 401 lwkt_reltoken(&p->p_token); 402 lwkt_reltoken(&proc_token); 403 return EBUSY; 404 } 405 406 /* not currently stopped */ 407 if (p->p_stat != SSTOP || 408 (p->p_flag & P_WAITED) == 0) { 409 lwkt_reltoken(&p->p_token); 410 lwkt_reltoken(&proc_token); 411 return EBUSY; 412 } 413 414 /* OK */ 415 break; 416 417 default: 418 lwkt_reltoken(&p->p_token); 419 lwkt_reltoken(&proc_token); 420 return EINVAL; 421 } 422 423 /* XXX lwp */ 424 lp = FIRST_LWP_IN_PROC(p); 425 #ifdef FIX_SSTEP 426 /* 427 * Single step fixup ala procfs 428 */ 429 FIX_SSTEP(lp); 430 #endif 431 432 /* 433 * Actually do the requests 434 */ 435 436 *res = 0; 437 438 switch (req) { 439 case PT_TRACE_ME: 440 /* set my trace flag and "owner" so it can read/write me */ 441 p->p_flag |= P_TRACED; 442 p->p_oppid = p->p_pptr->p_pid; 443 lwkt_reltoken(&p->p_token); 444 lwkt_reltoken(&proc_token); 445 return 0; 446 447 case PT_ATTACH: 448 /* security check done above */ 449 p->p_flag |= P_TRACED; 450 p->p_oppid = p->p_pptr->p_pid; 451 if (p->p_pptr != curp) 452 proc_reparent(p, curp); 453 data = SIGSTOP; 454 goto sendsig; /* in PT_CONTINUE below */ 455 456 case PT_STEP: 457 case PT_CONTINUE: 458 case PT_DETACH: 459 /* Zero means do not send any signal */ 460 if (data < 0 || data > _SIG_MAXSIG) { 461 lwkt_reltoken(&p->p_token); 462 lwkt_reltoken(&proc_token); 463 return EINVAL; 464 } 465 466 LWPHOLD(lp); 467 468 if (req == PT_STEP) { 469 if ((error = ptrace_single_step (lp))) { 470 LWPRELE(lp); 471 lwkt_reltoken(&p->p_token); 472 lwkt_reltoken(&proc_token); 473 return error; 474 } 475 } 476 477 if (addr != (void *)1) { 478 if ((error = ptrace_set_pc (lp, 479 (u_long)(uintfptr_t)addr))) { 480 LWPRELE(lp); 481 lwkt_reltoken(&p->p_token); 482 lwkt_reltoken(&proc_token); 483 return error; 484 } 485 } 486 LWPRELE(lp); 487 488 if (req == PT_DETACH) { 489 /* reset process parent */ 490 if (p->p_oppid != p->p_pptr->p_pid) { 491 struct proc *pp; 492 493 pp = pfind(p->p_oppid); 494 proc_reparent(p, pp ? pp : initproc); 495 } 496 497 p->p_flag &= ~(P_TRACED | P_WAITED); 498 p->p_oppid = 0; 499 500 /* should we send SIGCHLD? */ 501 } 502 503 sendsig: 504 /* 505 * Deliver or queue signal. If the process is stopped 506 * force it to be SACTIVE again. 507 */ 508 crit_enter(); 509 if (p->p_stat == SSTOP) { 510 p->p_xstat = data; 511 lp->lwp_flag |= LWP_BREAKTSLEEP; 512 proc_unstop(p); 513 } else if (data) { 514 ksignal(p, data); 515 } 516 crit_exit(); 517 lwkt_reltoken(&p->p_token); 518 lwkt_reltoken(&proc_token); 519 return 0; 520 521 case PT_WRITE_I: 522 case PT_WRITE_D: 523 write = 1; 524 /* fallthrough */ 525 case PT_READ_I: 526 case PT_READ_D: 527 /* 528 * NOTE! uio_offset represents the offset in the target 529 * process. The iov is in the current process (the guy 530 * making the ptrace call) so uio_td must be the current 531 * process (though for a SYSSPACE transfer it doesn't 532 * really matter). 533 */ 534 tmp = 0; 535 /* write = 0 set above */ 536 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; 537 iov.iov_len = sizeof(int); 538 uio.uio_iov = &iov; 539 uio.uio_iovcnt = 1; 540 uio.uio_offset = (off_t)(uintptr_t)addr; 541 uio.uio_resid = sizeof(int); 542 uio.uio_segflg = UIO_SYSSPACE; 543 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 544 uio.uio_td = curthread; 545 error = procfs_domem(curp, lp, NULL, &uio); 546 if (uio.uio_resid != 0) { 547 /* 548 * XXX procfs_domem() doesn't currently return ENOSPC, 549 * so I think write() can bogusly return 0. 550 * XXX what happens for short writes? We don't want 551 * to write partial data. 552 * XXX procfs_domem() returns EPERM for other invalid 553 * addresses. Convert this to EINVAL. Does this 554 * clobber returns of EPERM for other reasons? 555 */ 556 if (error == 0 || error == ENOSPC || error == EPERM) 557 error = EINVAL; /* EOF */ 558 } 559 if (!write) 560 *res = tmp; 561 lwkt_reltoken(&p->p_token); 562 lwkt_reltoken(&proc_token); 563 return (error); 564 565 case PT_IO: 566 /* 567 * NOTE! uio_offset represents the offset in the target 568 * process. The iov is in the current process (the guy 569 * making the ptrace call) so uio_td must be the current 570 * process. 571 */ 572 piod = addr; 573 iov.iov_base = piod->piod_addr; 574 iov.iov_len = piod->piod_len; 575 uio.uio_iov = &iov; 576 uio.uio_iovcnt = 1; 577 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; 578 uio.uio_resid = piod->piod_len; 579 uio.uio_segflg = UIO_USERSPACE; 580 uio.uio_td = curthread; 581 switch (piod->piod_op) { 582 case PIOD_READ_D: 583 case PIOD_READ_I: 584 uio.uio_rw = UIO_READ; 585 break; 586 case PIOD_WRITE_D: 587 case PIOD_WRITE_I: 588 uio.uio_rw = UIO_WRITE; 589 break; 590 default: 591 lwkt_reltoken(&p->p_token); 592 lwkt_reltoken(&proc_token); 593 return (EINVAL); 594 } 595 error = procfs_domem(curp, lp, NULL, &uio); 596 piod->piod_len -= uio.uio_resid; 597 lwkt_reltoken(&p->p_token); 598 lwkt_reltoken(&proc_token); 599 return (error); 600 601 case PT_KILL: 602 data = SIGKILL; 603 goto sendsig; /* in PT_CONTINUE above */ 604 605 #ifdef PT_SETREGS 606 case PT_SETREGS: 607 write = 1; 608 /* fallthrough */ 609 #endif /* PT_SETREGS */ 610 #ifdef PT_GETREGS 611 case PT_GETREGS: 612 /* write = 0 above */ 613 #endif /* PT_SETREGS */ 614 #if defined(PT_SETREGS) || defined(PT_GETREGS) 615 if (!procfs_validregs(lp)) { /* no P_SYSTEM procs please */ 616 lwkt_reltoken(&p->p_token); 617 lwkt_reltoken(&proc_token); 618 return EINVAL; 619 } else { 620 iov.iov_base = addr; 621 iov.iov_len = sizeof(struct reg); 622 uio.uio_iov = &iov; 623 uio.uio_iovcnt = 1; 624 uio.uio_offset = 0; 625 uio.uio_resid = sizeof(struct reg); 626 uio.uio_segflg = UIO_SYSSPACE; 627 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 628 uio.uio_td = curthread; 629 t = procfs_doregs(curp, lp, NULL, &uio); 630 lwkt_reltoken(&p->p_token); 631 lwkt_reltoken(&proc_token); 632 return t; 633 } 634 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */ 635 636 #ifdef PT_SETFPREGS 637 case PT_SETFPREGS: 638 write = 1; 639 /* fallthrough */ 640 #endif /* PT_SETFPREGS */ 641 #ifdef PT_GETFPREGS 642 case PT_GETFPREGS: 643 /* write = 0 above */ 644 #endif /* PT_SETFPREGS */ 645 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) 646 if (!procfs_validfpregs(lp)) { /* no P_SYSTEM procs please */ 647 lwkt_reltoken(&p->p_token); 648 lwkt_reltoken(&proc_token); 649 return EINVAL; 650 } else { 651 iov.iov_base = addr; 652 iov.iov_len = sizeof(struct fpreg); 653 uio.uio_iov = &iov; 654 uio.uio_iovcnt = 1; 655 uio.uio_offset = 0; 656 uio.uio_resid = sizeof(struct fpreg); 657 uio.uio_segflg = UIO_SYSSPACE; 658 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 659 uio.uio_td = curthread; 660 t = procfs_dofpregs(curp, lp, NULL, &uio); 661 lwkt_reltoken(&p->p_token); 662 lwkt_reltoken(&proc_token); 663 return t; 664 } 665 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */ 666 667 #ifdef PT_SETDBREGS 668 case PT_SETDBREGS: 669 write = 1; 670 /* fallthrough */ 671 #endif /* PT_SETDBREGS */ 672 #ifdef PT_GETDBREGS 673 case PT_GETDBREGS: 674 /* write = 0 above */ 675 #endif /* PT_SETDBREGS */ 676 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS) 677 if (!procfs_validdbregs(lp)) { /* no P_SYSTEM procs please */ 678 lwkt_reltoken(&p->p_token); 679 lwkt_reltoken(&proc_token); 680 return EINVAL; 681 } else { 682 iov.iov_base = addr; 683 iov.iov_len = sizeof(struct dbreg); 684 uio.uio_iov = &iov; 685 uio.uio_iovcnt = 1; 686 uio.uio_offset = 0; 687 uio.uio_resid = sizeof(struct dbreg); 688 uio.uio_segflg = UIO_SYSSPACE; 689 uio.uio_rw = write ? UIO_WRITE : UIO_READ; 690 uio.uio_td = curthread; 691 t = procfs_dodbregs(curp, lp, NULL, &uio); 692 lwkt_reltoken(&p->p_token); 693 lwkt_reltoken(&proc_token); 694 return t; 695 } 696 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */ 697 698 default: 699 break; 700 } 701 702 lwkt_reltoken(&p->p_token); 703 lwkt_reltoken(&proc_token); 704 return 0; 705 } 706 707 int 708 trace_req(struct proc *p) 709 { 710 return 1; 711 } 712 713 /* 714 * stopevent() 715 * 716 * Stop a process because of a procfs event. Stay stopped until p->p_step 717 * is cleared (cleared by PIOCCONT in procfs). 718 * 719 * MPSAFE 720 */ 721 void 722 stopevent(struct proc *p, unsigned int event, unsigned int val) 723 { 724 /* 725 * Set event info. Recheck p_stops in case we are 726 * racing a close() on procfs. 727 */ 728 spin_lock(&p->p_spin); 729 if ((p->p_stops & event) == 0) { 730 spin_unlock(&p->p_spin); 731 return; 732 } 733 p->p_xstat = val; 734 p->p_stype = event; 735 p->p_step = 1; 736 tsleep_interlock(&p->p_step, 0); 737 spin_unlock(&p->p_spin); 738 739 /* 740 * Wakeup any PIOCWAITing procs and wait for p_step to 741 * be cleared. 742 */ 743 for (;;) { 744 wakeup(&p->p_stype); 745 tsleep(&p->p_step, PINTERLOCKED, "stopevent", 0); 746 spin_lock(&p->p_spin); 747 if (p->p_step == 0) { 748 spin_unlock(&p->p_spin); 749 break; 750 } 751 tsleep_interlock(&p->p_step, 0); 752 spin_unlock(&p->p_spin); 753 } 754 } 755 756