1 /*- 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)kvm_proc.c 5.23 (Berkeley) 04/03/92"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 /* 13 * Proc traversal interface for kvm. ps and w are (probably) the exclusive 14 * users of this code, so we've factored it out into a separate module. 15 * Thus, we keep this grunge out of the other kvm applications (i.e., 16 * most other applications are interested only in open/close/read/nlist). 17 */ 18 19 #include <sys/param.h> 20 #include <sys/user.h> 21 #include <sys/proc.h> 22 #include <sys/exec.h> 23 #include <sys/stat.h> 24 #include <sys/ioctl.h> 25 #include <sys/tty.h> 26 #include <nlist.h> 27 #include <kvm.h> 28 29 #include <vm/vm.h> 30 #include <vm/vm_param.h> 31 #include <vm/swap_pager.h> 32 33 #include <sys/kinfo.h> 34 #include <sys/kinfo_proc.h> 35 36 #include <limits.h> 37 #include <ndbm.h> 38 #include <paths.h> 39 40 #include "kvm_private.h" 41 42 static char * 43 kvm_readswap(kd, p, va, cnt) 44 kvm_t *kd; 45 const struct proc *p; 46 u_long va; 47 u_long *cnt; 48 { 49 register int ix; 50 register u_long addr, head; 51 register u_long offset, pagestart, sbstart, pgoff; 52 register off_t seekpoint; 53 struct vm_map_entry vme; 54 struct vm_object vmo; 55 struct pager_struct pager; 56 struct swpager swap; 57 struct swblock swb; 58 static char page[NBPG]; 59 60 head = (u_long)&p->p_vmspace->vm_map.header; 61 /* 62 * Look through the address map for the memory object 63 * that corresponds to the given virtual address. 64 * The header just has the entire valid range. 65 */ 66 addr = head; 67 while (1) { 68 if (kvm_read(kd, addr, (char *)&vme, sizeof(vme)) != 69 sizeof(vme)) 70 return (0); 71 72 if (va >= vme.start && va <= vme.end && 73 vme.object.vm_object != 0) 74 break; 75 76 addr = (u_long)vme.next; 77 if (addr == 0 || addr == head) 78 return (0); 79 } 80 /* 81 * We found the right object -- follow shadow links. 82 */ 83 offset = va - vme.start + vme.offset; 84 addr = (u_long)vme.object.vm_object; 85 while (1) { 86 if (kvm_read(kd, addr, (char *)&vmo, sizeof(vmo)) != 87 sizeof(vmo)) 88 return (0); 89 addr = (u_long)vmo.shadow; 90 if (addr == 0) 91 break; 92 offset += vmo.shadow_offset; 93 } 94 if (vmo.pager == 0) 95 return (0); 96 97 offset += vmo.paging_offset; 98 /* 99 * Read in the pager info and make sure it's a swap device. 100 */ 101 addr = (u_long)vmo.pager; 102 if (kvm_read(kd, addr, (char *)&pager, sizeof(pager)) != sizeof(pager) 103 || pager.pg_type != PG_SWAP) 104 return (0); 105 106 /* 107 * Read in the swap_pager private data, and compute the 108 * swap offset. 109 */ 110 addr = (u_long)pager.pg_data; 111 if (kvm_read(kd, addr, (char *)&swap, sizeof(swap)) != sizeof(swap)) 112 return (0); 113 ix = offset / dbtob(swap.sw_bsize); 114 if (swap.sw_blocks == 0 || ix >= swap.sw_nblocks) 115 return (0); 116 117 addr = (u_long)&swap.sw_blocks[ix]; 118 if (kvm_read(kd, addr, (char *)&swb, sizeof(swb)) != sizeof(swb)) 119 return (0); 120 121 sbstart = (offset / dbtob(swap.sw_bsize)) * dbtob(swap.sw_bsize); 122 sbstart /= NBPG; 123 pagestart = offset / NBPG; 124 pgoff = pagestart - sbstart; 125 126 if (swb.swb_block == 0 || (swb.swb_mask & (1 << pgoff)) == 0) 127 return (0); 128 129 seekpoint = dbtob(swb.swb_block) + ctob(pgoff); 130 errno = 0; 131 if (lseek(kd->swfd, seekpoint, 0) == -1 && errno != 0) 132 return (0); 133 if (read(kd->swfd, page, sizeof(page)) != sizeof(page)) 134 return (0); 135 136 offset %= NBPG; 137 *cnt = NBPG - offset; 138 return (&page[offset]); 139 } 140 141 #define KREAD(kd, addr, obj) \ 142 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 143 144 /* 145 * Read proc's from memory file into buffer bp, which has space to hold 146 * at most maxcnt procs. 147 */ 148 static int 149 kvm_proclist(kd, what, arg, p, bp, maxcnt) 150 kvm_t *kd; 151 int what, arg; 152 struct proc *p; 153 struct kinfo_proc *bp; 154 int maxcnt; 155 { 156 register int cnt = 0; 157 struct eproc eproc; 158 struct pgrp pgrp; 159 struct session sess; 160 struct tty tty; 161 struct proc proc; 162 163 for (; cnt < maxcnt && p != 0; p = proc.p_nxt) { 164 if (KREAD(kd, (u_long)p, &proc)) { 165 _kvm_err(kd, kd->program, "can't read proc at %x", p); 166 return (-1); 167 } 168 if (KREAD(kd, (u_long)proc.p_cred, &eproc.e_pcred) == 0) 169 KREAD(kd, (u_long)eproc.e_pcred.pc_ucred, 170 &eproc.e_ucred); 171 172 switch(ki_op(what)) { 173 174 case KINFO_PROC_PID: 175 if (proc.p_pid != (pid_t)arg) 176 continue; 177 break; 178 179 case KINFO_PROC_UID: 180 if (eproc.e_ucred.cr_uid != (uid_t)arg) 181 continue; 182 break; 183 184 case KINFO_PROC_RUID: 185 if (eproc.e_pcred.p_ruid != (uid_t)arg) 186 continue; 187 break; 188 } 189 /* 190 * We're going to add another proc to the set. If this 191 * will overflow the buffer, assume the reason is because 192 * nprocs (or the proc list) is corrupt and declare an error. 193 */ 194 if (cnt >= maxcnt) { 195 _kvm_err(kd, kd->program, "nprocs corrupt"); 196 return (-1); 197 } 198 /* 199 * gather eproc 200 */ 201 eproc.e_paddr = p; 202 if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) { 203 _kvm_err(kd, kd->program, "can't read pgrp at %x", 204 proc.p_pgrp); 205 return (-1); 206 } 207 eproc.e_sess = pgrp.pg_session; 208 eproc.e_pgid = pgrp.pg_id; 209 eproc.e_jobc = pgrp.pg_jobc; 210 if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) { 211 _kvm_err(kd, kd->program, "can't read session at %x", 212 pgrp.pg_session); 213 return (-1); 214 } 215 if ((proc.p_flag & SCTTY) && sess.s_ttyp != NULL) { 216 if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) { 217 _kvm_err(kd, kd->program, 218 "can't read tty at %x", sess.s_ttyp); 219 return (-1); 220 } 221 eproc.e_tdev = tty.t_dev; 222 eproc.e_tsess = tty.t_session; 223 if (tty.t_pgrp != NULL) { 224 if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) { 225 _kvm_err(kd, kd->program, 226 "can't read tpgrp at &x", 227 tty.t_pgrp); 228 return (-1); 229 } 230 eproc.e_tpgid = pgrp.pg_id; 231 } else 232 eproc.e_tpgid = -1; 233 } else 234 eproc.e_tdev = NODEV; 235 eproc.e_flag = sess.s_ttyvp ? EPROC_CTTY : 0; 236 if (sess.s_leader == p) 237 eproc.e_flag |= EPROC_SLEADER; 238 if (proc.p_wmesg) 239 (void)kvm_read(kd, (u_long)proc.p_wmesg, 240 eproc.e_wmesg, WMESGLEN); 241 242 #ifdef sparc 243 (void)kvm_read(kd, (u_long)&proc.p_vmspace->vm_rssize, 244 (char *)&eproc.e_vm.vm_rssize, 245 sizeof(eproc.e_vm.vm_rssize)); 246 (void)kvm_read(kd, (u_long)&proc.p_vmspace->vm_tsize, 247 (char *)&eproc.e_vm.vm_tsize, 248 3 * sizeof(eproc.e_vm.vm_rssize)); /* XXX */ 249 #else 250 (void)kvm_read(kd, (u_long)proc.p_vmspace, 251 (char *)&eproc.e_vm, sizeof(eproc.e_vm)); 252 #endif 253 eproc.e_xsize = eproc.e_xrssize = 0; 254 eproc.e_xccount = eproc.e_xswrss = 0; 255 256 switch (ki_op(what)) { 257 258 case KINFO_PROC_PGRP: 259 if (eproc.e_pgid != (pid_t)arg) 260 continue; 261 break; 262 263 case KINFO_PROC_TTY: 264 if ((proc.p_flag&SCTTY) == 0 || 265 eproc.e_tdev != (dev_t)arg) 266 continue; 267 break; 268 } 269 bcopy((char *)&proc, (char *)&bp->kp_proc, sizeof(proc)); 270 bcopy((char *)&eproc, (char *)&bp->kp_eproc, sizeof(eproc)); 271 ++bp; 272 ++cnt; 273 } 274 return (cnt); 275 } 276 277 /* 278 * Build proc info array by reading in proc list from a crash dump. 279 * Return number of procs read. maxcnt is the max we will read. 280 */ 281 static int 282 kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt) 283 kvm_t *kd; 284 int what, arg; 285 u_long a_allproc; 286 u_long a_zombproc; 287 int maxcnt; 288 { 289 register struct kinfo_proc *bp = kd->procbase; 290 register int acnt, zcnt; 291 struct proc *p; 292 293 if (KREAD(kd, a_allproc, &p)) { 294 _kvm_err(kd, kd->program, "cannot read allproc"); 295 return (-1); 296 } 297 acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt); 298 if (acnt < 0) 299 return (acnt); 300 301 if (KREAD(kd, a_zombproc, &p)) { 302 _kvm_err(kd, kd->program, "cannot read zombproc"); 303 return (-1); 304 } 305 zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt); 306 if (zcnt < 0) 307 zcnt = 0; 308 309 return (acnt + zcnt); 310 } 311 312 struct kinfo_proc * 313 kvm_getprocs(kd, op, arg, cnt) 314 kvm_t *kd; 315 int op, arg; 316 int *cnt; 317 { 318 int size, st, nprocs; 319 320 if (kd->procbase != 0) { 321 free((void *)kd->procbase); 322 /* 323 * Clear this pointer in case this call fails. Otherwise, 324 * kvm_close() will free it again. 325 */ 326 kd->procbase = 0; 327 } 328 if (ISALIVE(kd)) { 329 size = 0; 330 st = getkerninfo(op, NULL, &size, arg); 331 if (st < 0) { 332 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 333 return (0); 334 } 335 kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, st); 336 if (kd->procbase == 0) 337 return (0); 338 size = st; 339 st = getkerninfo(op, kd->procbase, &size, arg); 340 if (st < 0) { 341 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 342 return (0); 343 } 344 if (size % sizeof(struct kinfo_proc) != 0) { 345 _kvm_err(kd, kd->program, 346 "proc size mismatch (%d total, %d chunks)", 347 size, sizeof(struct kinfo_proc)); 348 return (0); 349 } 350 nprocs = size / sizeof(struct kinfo_proc); 351 } else { 352 struct nlist nl[4], *p; 353 354 nl[0].n_name = "_nprocs"; 355 nl[1].n_name = "_allproc"; 356 nl[2].n_name = "_zombproc"; 357 nl[3].n_name = 0; 358 359 if (kvm_nlist(kd, nl) != 0) { 360 for (p = nl; p->n_type != 0; ++p) 361 ; 362 _kvm_err(kd, kd->program, 363 "%s: no such symbol", p->n_name); 364 return (0); 365 } 366 if (KREAD(kd, nl[0].n_value, &nprocs)) { 367 _kvm_err(kd, kd->program, "can't read nprocs"); 368 return (0); 369 } 370 size = nprocs * sizeof(struct kinfo_proc); 371 kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size); 372 if (kd->procbase == 0) 373 return (0); 374 375 nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value, 376 nl[2].n_value, nprocs); 377 #ifdef notdef 378 size = nprocs * sizeof(struct kinfo_proc); 379 (void)realloc(kd->procbase, size); 380 #endif 381 } 382 *cnt = nprocs; 383 return (kd->procbase); 384 } 385 386 void 387 _kvm_freeprocs(kd) 388 kvm_t *kd; 389 { 390 if (kd->procbase) { 391 free(kd->procbase); 392 kd->procbase = 0; 393 } 394 } 395 396 static void * 397 _kvm_realloc(kd, p, n) 398 kvm_t *kd; 399 void *p; 400 int n; 401 { 402 void *np = (void *)realloc(p, n); 403 404 if (np == 0) 405 _kvm_err(kd, kd->program, "out of memory"); 406 return (np); 407 } 408 409 #ifndef MAX 410 #define MAX(a, b) ((a) > (b) ? (a) : (b)) 411 #endif 412 413 /* 414 * Read in an argument vector from the user address space of process p. 415 * addr if the user-space base address of narg null-terminated contiguous 416 * strings. This is used to read in both the command arguments and 417 * environment strings. Read at most maxcnt characters of strings. 418 */ 419 static char ** 420 kvm_argv(kd, p, addr, narg, maxcnt) 421 kvm_t *kd; 422 struct proc *p; 423 register u_long addr; 424 register int narg; 425 register int maxcnt; 426 { 427 register char *cp; 428 register int len, cc; 429 register char **argv; 430 431 /* 432 * Check that there aren't an unreasonable number of agruments, 433 * and that the address is in user space. 434 */ 435 if (narg > 512 || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 436 return (0); 437 438 if (kd->argv == 0) { 439 /* 440 * Try to avoid reallocs. 441 */ 442 kd->argc = MAX(narg + 1, 32); 443 kd->argv = (char **)_kvm_malloc(kd, kd->argc * 444 sizeof(*kd->argv)); 445 if (kd->argv == 0) 446 return (0); 447 } else if (narg + 1 > kd->argc) { 448 kd->argc = MAX(2 * kd->argc, narg + 1); 449 kd->argv = (char **)_kvm_realloc(kd, kd->argv); 450 if (kd->argv == 0) 451 return (0); 452 } 453 if (kd->argspc == 0) { 454 kd->argspc = (char *)_kvm_malloc(kd, NBPG); 455 if (kd->argspc == 0) 456 return (0); 457 kd->arglen = NBPG; 458 } 459 cp = kd->argspc; 460 argv = kd->argv; 461 *argv = cp; 462 len = 0; 463 /* 464 * Loop over pages, filling in the argument vector. 465 */ 466 while (addr < VM_MAXUSER_ADDRESS) { 467 cc = NBPG - (addr & PGOFSET); 468 if (maxcnt > 0 && cc > maxcnt - len) 469 cc = maxcnt - len;; 470 if (len + cc > kd->arglen) { 471 register int off; 472 register char **pp; 473 register char *op = kd->argspc; 474 475 kd->arglen *= 2; 476 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, 477 kd->arglen); 478 if (kd->argspc == 0) 479 return (0); 480 cp = &kd->argspc[len]; 481 /* 482 * Adjust argv pointers in case realloc moved 483 * the string space. 484 */ 485 off = kd->argspc - op; 486 for (pp = kd->argv; pp < argv; ++pp) 487 *pp += off; 488 } 489 if (kvm_uread(kd, p, addr, cp, cc) != cc) 490 /* XXX */ 491 return (0); 492 len += cc; 493 addr += cc; 494 495 if (maxcnt == 0 && len > 16 * NBPG) 496 /* sanity */ 497 return (0); 498 499 while (--cc >= 0) { 500 if (*cp++ == 0) { 501 if (--narg <= 0) { 502 *++argv = 0; 503 return (kd->argv); 504 } else 505 *++argv = cp; 506 } 507 } 508 if (maxcnt > 0 && len >= maxcnt) { 509 /* 510 * We're stopping prematurely. Terminate the 511 * argv and current string. 512 */ 513 *++argv = 0; 514 *cp = 0; 515 return (kd->argv); 516 } 517 } 518 } 519 520 static void 521 ps_str_a(p, addr, n) 522 struct ps_strings *p; 523 u_long *addr; 524 int *n; 525 { 526 *addr = (u_long)p->ps_argvstr; 527 *n = p->ps_nargvstr; 528 } 529 530 static void 531 ps_str_e(p, addr, n) 532 struct ps_strings *p; 533 u_long *addr; 534 int *n; 535 { 536 *addr = (u_long)p->ps_envstr; 537 *n = p->ps_nenvstr; 538 } 539 540 /* 541 * Determine if the proc indicated by p is still active. 542 * This test is not 100% foolproof in theory, but chances of 543 * being wrong are very low. 544 */ 545 static int 546 proc_verify(kd, kernp, p) 547 kvm_t *kd; 548 u_long kernp; 549 const struct proc *p; 550 { 551 struct proc kernproc; 552 553 /* 554 * Just read in the whole proc. It's not that big relative 555 * to the cost of the read system call. 556 */ 557 if (kvm_read(kd, kernp, (char *)&kernproc, sizeof(kernproc)) != 558 sizeof(kernproc)) 559 return (0); 560 return (p->p_pid == kernproc.p_pid && 561 (kernproc.p_stat != SZOMB || p->p_stat == SZOMB)); 562 } 563 564 static char ** 565 kvm_doargv(kd, kp, nchr, info) 566 kvm_t *kd; 567 const struct kinfo_proc *kp; 568 int nchr; 569 int (*info)(struct ps_strings*, u_long *, int *); 570 { 571 register const struct proc *p = &kp->kp_proc; 572 register char **ap; 573 u_long addr; 574 int cnt; 575 struct ps_strings arginfo; 576 577 /* 578 * Pointers are stored at the top of the user stack. 579 */ 580 if (p->p_stat == SZOMB || 581 kvm_uread(kd, p, USRSTACK - sizeof(arginfo), (char *)&arginfo, 582 sizeof(arginfo)) != sizeof(arginfo)) 583 return (0); 584 585 (*info)(&arginfo, &addr, &cnt); 586 ap = kvm_argv(kd, p, addr, cnt, nchr); 587 /* 588 * For live kernels, make sure this process didn't go away. 589 */ 590 if (ap != 0 && ISALIVE(kd) && 591 !proc_verify(kd, (u_long)kp->kp_eproc.e_paddr, p)) 592 ap = 0; 593 return (ap); 594 } 595 596 /* 597 * Get the command args. This code is now machine independent. 598 */ 599 char ** 600 kvm_getargv(kd, kp, nchr) 601 kvm_t *kd; 602 const struct kinfo_proc *kp; 603 int nchr; 604 { 605 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 606 } 607 608 char ** 609 kvm_getenvv(kd, kp, nchr) 610 kvm_t *kd; 611 const struct kinfo_proc *kp; 612 int nchr; 613 { 614 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 615 } 616 617 /* 618 * Read from user space. The user context is given by p. 619 */ 620 ssize_t 621 kvm_uread(kd, p, uva, buf, len) 622 kvm_t *kd; 623 register struct proc *p; 624 register u_long uva; 625 register char *buf; 626 register size_t len; 627 { 628 register char *cp; 629 630 cp = buf; 631 while (len > 0) { 632 u_long pa; 633 register int cc; 634 635 cc = _kvm_uvatop(kd, p, uva, &pa); 636 if (cc > 0) { 637 if (cc > len) 638 cc = len; 639 errno = 0; 640 if (lseek(kd->pmfd, (off_t)pa, 0) == -1 && errno != 0) { 641 _kvm_err(kd, 0, "invalid address (%x)", uva); 642 break; 643 } 644 cc = read(kd->pmfd, cp, cc); 645 if (cc < 0) { 646 _kvm_syserr(kd, 0, _PATH_MEM); 647 break; 648 } else if (cc < len) { 649 _kvm_err(kd, kd->program, "short read"); 650 break; 651 } 652 } else if (ISALIVE(kd)) { 653 /* try swap */ 654 register char *dp; 655 int cnt; 656 657 dp = kvm_readswap(kd, p, uva, &cnt); 658 if (dp == 0) { 659 _kvm_err(kd, 0, "invalid address (%x)", uva); 660 return (0); 661 } 662 cc = MIN(cnt, len); 663 bcopy(dp, cp, cc); 664 } else 665 break; 666 cp += cc; 667 uva += cc; 668 len -= cc; 669 } 670 return (ssize_t)(cp - buf); 671 } 672