1 /*- 2 * Copyright (c) 1989, 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software developed by the Computer Systems 6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract 7 * BG 91-66 and contributed to Berkeley. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $FreeBSD: src/lib/libkvm/kvm_proc.c,v 1.25.2.3 2002/08/24 07:27:46 kris Exp $ 34 * 35 * @(#)kvm_proc.c 8.3 (Berkeley) 9/23/93 36 */ 37 38 /* 39 * Proc traversal interface for kvm. ps and w are (probably) the exclusive 40 * users of this code, so we've factored it out into a separate module. 41 * Thus, we keep this grunge out of the other kvm applications (i.e., 42 * most other applications are interested only in open/close/read/nlist). 43 */ 44 45 #include <sys/user.h> /* MUST BE FIRST */ 46 #include <sys/conf.h> 47 #include <sys/param.h> 48 #include <sys/proc.h> 49 #include <sys/exec.h> 50 #include <sys/stat.h> 51 #include <sys/globaldata.h> 52 #include <sys/ioctl.h> 53 #include <sys/tty.h> 54 #include <sys/file.h> 55 #include <sys/jail.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <stddef.h> 59 #include <unistd.h> 60 #include <nlist.h> 61 62 #include <cpu/pmap.h> 63 #include <vm/vm.h> 64 #include <vm/vm_param.h> 65 #include <vm/swap_pager.h> 66 67 #include <sys/sysctl.h> 68 69 #include <limits.h> 70 #include <memory.h> 71 #include <paths.h> 72 73 #include "kvm.h" 74 #include "kvm_private.h" 75 76 dev_t dev2udev(cdev_t dev); 77 78 #define KREAD(kd, addr, obj) \ 79 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 80 #define KREADSTR(kd, addr) \ 81 kvm_readstr(kd, (u_long)addr, NULL, NULL) 82 83 static struct kinfo_proc * 84 kinfo_resize_proc(kvm_t *kd, struct kinfo_proc *bp) 85 { 86 if (bp < kd->procend) 87 return bp; 88 89 size_t pos = bp - kd->procend; 90 size_t size = kd->procend - kd->procbase; 91 92 if (size == 0) 93 size = 8; 94 else 95 size *= 2; 96 kd->procbase = _kvm_realloc(kd, kd->procbase, sizeof(*bp) * size); 97 if (kd->procbase == NULL) 98 return NULL; 99 kd->procend = kd->procbase + size; 100 bp = kd->procbase + pos; 101 return bp; 102 } 103 104 /* 105 * note: this function is also used by /usr/src/sys/kern/kern_kinfo.c as 106 * compiled by userland. 107 */ 108 dev_t 109 dev2udev(cdev_t dev) 110 { 111 if (dev == NULL) 112 return NOUDEV; 113 if ((dev->si_umajor & 0xffffff00) || 114 (dev->si_uminor & 0x0000ff00)) { 115 return NOUDEV; 116 } 117 return((dev->si_umajor << 8) | dev->si_uminor); 118 } 119 120 /* 121 * Helper routine which traverses the left hand side of a red-black sub-tree. 122 */ 123 static uintptr_t 124 kvm_lwptraverse(kvm_t *kd, struct lwp *lwp, uintptr_t lwppos) 125 { 126 for (;;) { 127 if (KREAD(kd, lwppos, lwp)) { 128 _kvm_err(kd, kd->program, "can't read lwp at %p", 129 (void *)lwppos); 130 return ((uintptr_t)-1); 131 } 132 if (lwp->u.lwp_rbnode.rbe_left == NULL) 133 break; 134 lwppos = (uintptr_t)lwp->u.lwp_rbnode.rbe_left; 135 } 136 return(lwppos); 137 } 138 139 /* 140 * Iterate LWPs in a process. 141 * 142 * The first lwp in a red-black tree is a left-side traversal of the tree. 143 */ 144 static uintptr_t 145 kvm_firstlwp(kvm_t *kd, struct lwp *lwp, struct proc *proc) 146 { 147 return(kvm_lwptraverse(kd, lwp, (uintptr_t)proc->p_lwp_tree.rbh_root)); 148 } 149 150 /* 151 * If the current element is the left side of the parent the next element 152 * will be a left side traversal of the parent's right side. If the parent 153 * has no right side the next element will be the parent. 154 * 155 * If the current element is the right side of the parent the next element 156 * is the parent. 157 * 158 * If the parent is NULL we are done. 159 */ 160 static uintptr_t 161 kvm_nextlwp(kvm_t *kd, uintptr_t lwppos, struct lwp *lwp) 162 { 163 uintptr_t nextpos; 164 165 nextpos = (uintptr_t)lwp->u.lwp_rbnode.rbe_parent; 166 if (nextpos) { 167 if (KREAD(kd, nextpos, lwp)) { 168 _kvm_err(kd, kd->program, "can't read lwp at %p", 169 (void *)lwppos); 170 return ((uintptr_t)-1); 171 } 172 if (lwppos == (uintptr_t)lwp->u.lwp_rbnode.rbe_left) { 173 /* 174 * If we had gone down the left side the next element 175 * is a left hand traversal of the parent's right 176 * side, or the parent itself if there is no right 177 * side. 178 */ 179 lwppos = (uintptr_t)lwp->u.lwp_rbnode.rbe_right; 180 if (lwppos) 181 nextpos = kvm_lwptraverse(kd, lwp, lwppos); 182 } else { 183 /* 184 * If we had gone down the right side the next 185 * element is the parent. 186 */ 187 /* nextpos = nextpos */ 188 } 189 } 190 return(nextpos); 191 } 192 193 /* 194 * Read proc's from memory file into buffer bp, which has space to hold 195 * at most maxcnt procs. 196 */ 197 static int 198 kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p, 199 struct kinfo_proc *bp) 200 { 201 struct pgrp pgrp; 202 struct pgrp tpgrp; 203 struct globaldata gdata; 204 struct session sess; 205 struct session tsess; 206 struct tty tty; 207 struct proc proc; 208 struct ucred ucred; 209 struct thread thread; 210 struct proc pproc; 211 struct cdev cdev; 212 struct vmspace vmspace; 213 struct prison prison; 214 struct sigacts sigacts; 215 struct lwp lwp; 216 uintptr_t lwppos; 217 int count; 218 char *wmesg; 219 220 count = 0; 221 222 for (; p != NULL; p = proc.p_list.le_next) { 223 if (KREAD(kd, (u_long)p, &proc)) { 224 _kvm_err(kd, kd->program, "can't read proc at %p", p); 225 return (-1); 226 } 227 if (KREAD(kd, (u_long)proc.p_ucred, &ucred)) { 228 _kvm_err(kd, kd->program, "can't read ucred at %p", 229 proc.p_ucred); 230 return (-1); 231 } 232 proc.p_ucred = &ucred; 233 234 switch(what & ~KERN_PROC_FLAGMASK) { 235 236 case KERN_PROC_PID: 237 if (proc.p_pid != (pid_t)arg) 238 continue; 239 break; 240 241 case KERN_PROC_UID: 242 if (ucred.cr_uid != (uid_t)arg) 243 continue; 244 break; 245 246 case KERN_PROC_RUID: 247 if (ucred.cr_ruid != (uid_t)arg) 248 continue; 249 break; 250 } 251 252 if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) { 253 _kvm_err(kd, kd->program, "can't read pgrp at %p", 254 proc.p_pgrp); 255 return (-1); 256 } 257 proc.p_pgrp = &pgrp; 258 if (proc.p_pptr) { 259 if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) { 260 _kvm_err(kd, kd->program, "can't read pproc at %p", 261 proc.p_pptr); 262 return (-1); 263 } 264 proc.p_pptr = &pproc; 265 } 266 267 if (proc.p_sigacts) { 268 if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) { 269 _kvm_err(kd, kd->program, 270 "can't read sigacts at %p", 271 proc.p_sigacts); 272 return (-1); 273 } 274 proc.p_sigacts = &sigacts; 275 } 276 277 if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) { 278 _kvm_err(kd, kd->program, "can't read session at %p", 279 pgrp.pg_session); 280 return (-1); 281 } 282 pgrp.pg_session = &sess; 283 284 if ((proc.p_flags & P_CONTROLT) && sess.s_ttyp != NULL) { 285 if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) { 286 _kvm_err(kd, kd->program, 287 "can't read tty at %p", sess.s_ttyp); 288 return (-1); 289 } 290 sess.s_ttyp = &tty; 291 if (tty.t_dev != NULL) { 292 if (KREAD(kd, (u_long)tty.t_dev, &cdev)) 293 tty.t_dev = NULL; 294 else 295 tty.t_dev = &cdev; 296 } 297 if (tty.t_pgrp != NULL) { 298 if (KREAD(kd, (u_long)tty.t_pgrp, &tpgrp)) { 299 _kvm_err(kd, kd->program, 300 "can't read tpgrp at %p", 301 tty.t_pgrp); 302 return (-1); 303 } 304 tty.t_pgrp = &tpgrp; 305 } 306 if (tty.t_session != NULL) { 307 if (KREAD(kd, (u_long)tty.t_session, &tsess)) { 308 _kvm_err(kd, kd->program, 309 "can't read tsess at %p", 310 tty.t_session); 311 return (-1); 312 } 313 tty.t_session = &tsess; 314 } 315 } 316 317 if (KREAD(kd, (u_long)proc.p_vmspace, &vmspace)) { 318 _kvm_err(kd, kd->program, "can't read vmspace at %p", 319 proc.p_vmspace); 320 return (-1); 321 } 322 proc.p_vmspace = &vmspace; 323 324 if (ucred.cr_prison != NULL) { 325 if (KREAD(kd, (u_long)ucred.cr_prison, &prison)) { 326 _kvm_err(kd, kd->program, "can't read prison at %p", 327 ucred.cr_prison); 328 return (-1); 329 } 330 ucred.cr_prison = &prison; 331 } 332 333 switch (what & ~KERN_PROC_FLAGMASK) { 334 335 case KERN_PROC_PGRP: 336 if (proc.p_pgrp->pg_id != (pid_t)arg) 337 continue; 338 break; 339 340 case KERN_PROC_TTY: 341 if ((proc.p_flags & P_CONTROLT) == 0 || 342 dev2udev(proc.p_pgrp->pg_session->s_ttyp->t_dev) 343 != (dev_t)arg) 344 continue; 345 break; 346 } 347 348 if ((bp = kinfo_resize_proc(kd, bp)) == NULL) 349 return (-1); 350 fill_kinfo_proc(&proc, bp); 351 bp->kp_paddr = (uintptr_t)p; 352 353 lwppos = kvm_firstlwp(kd, &lwp, &proc); 354 if (lwppos == 0) { 355 bp++; /* Just export the proc then */ 356 count++; 357 } 358 while (lwppos && lwppos != (uintptr_t)-1) { 359 if (p != lwp.lwp_proc) { 360 _kvm_err(kd, kd->program, "lwp has wrong parent"); 361 return (-1); 362 } 363 lwp.lwp_proc = &proc; 364 if (KREAD(kd, (u_long)lwp.lwp_thread, &thread)) { 365 _kvm_err(kd, kd->program, "can't read thread at %p", 366 lwp.lwp_thread); 367 return (-1); 368 } 369 lwp.lwp_thread = &thread; 370 371 if (thread.td_gd) { 372 if (KREAD(kd, (u_long)thread.td_gd, &gdata)) { 373 _kvm_err(kd, kd->program, "can't read" 374 " gd at %p", 375 thread.td_gd); 376 return(-1); 377 } 378 thread.td_gd = &gdata; 379 } 380 if (thread.td_wmesg) { 381 wmesg = (void *)KREADSTR(kd, thread.td_wmesg); 382 if (wmesg == NULL) { 383 _kvm_err(kd, kd->program, "can't read" 384 " wmesg %p", 385 thread.td_wmesg); 386 return(-1); 387 } 388 thread.td_wmesg = wmesg; 389 } else { 390 wmesg = NULL; 391 } 392 393 if ((bp = kinfo_resize_proc(kd, bp)) == NULL) 394 return (-1); 395 fill_kinfo_proc(&proc, bp); 396 fill_kinfo_lwp(&lwp, &bp->kp_lwp); 397 bp->kp_paddr = (uintptr_t)p; 398 bp++; 399 count++; 400 if (wmesg) 401 free(wmesg); 402 if ((what & KERN_PROC_FLAG_LWP) == 0) 403 break; 404 lwppos = kvm_nextlwp(kd, lwppos, &lwp); 405 } 406 if (lwppos == (uintptr_t)-1) 407 return(-1); 408 } 409 return (count); 410 } 411 412 /* 413 * Build proc info array by reading in proc list from a crash dump. 414 * We reallocate kd->procbase as necessary. 415 */ 416 static int 417 kvm_deadprocs(kvm_t *kd, int what, int arg, int allproc_hsize) 418 { 419 struct kinfo_proc *bp; 420 struct proc *p; 421 struct proclist **pl; 422 int cnt, partcnt, n; 423 u_long nextoff; 424 u_long a_allproc; 425 426 cnt = partcnt = 0; 427 nextoff = 0; 428 429 /* 430 * Dynamically allocate space for all the elements of the 431 * allprocs array and KREAD() them. 432 */ 433 pl = _kvm_malloc(kd, allproc_hsize * sizeof(struct proclist *)); 434 for (n = 0; n < allproc_hsize; n++) { 435 pl[n] = _kvm_malloc(kd, sizeof(struct proclist)); 436 a_allproc = sizeof(struct procglob) * n + 437 offsetof(struct procglob, allproc); 438 nextoff = a_allproc; 439 if (KREAD(kd, (u_long)nextoff, pl[n])) { 440 _kvm_err(kd, kd->program, "can't read proclist at 0x%lx", 441 a_allproc); 442 return (-1); 443 } 444 445 /* Ignore empty proclists */ 446 if (LIST_EMPTY(pl[n])) 447 continue; 448 449 bp = kd->procbase + cnt; 450 p = pl[n]->lh_first; 451 partcnt = kvm_proclist(kd, what, arg, p, bp); 452 if (partcnt < 0) { 453 free(pl[n]); 454 return (partcnt); 455 } 456 457 cnt += partcnt; 458 free(pl[n]); 459 } 460 461 return (cnt); 462 } 463 464 struct kinfo_proc * 465 kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt) 466 { 467 int mib[4], st, nprocs, allproc_hsize; 468 int miblen = ((op & ~KERN_PROC_FLAGMASK) == KERN_PROC_ALL) ? 3 : 4; 469 size_t size; 470 471 if (kd->procbase != NULL) { 472 free(kd->procbase); 473 kd->procbase = NULL; 474 } 475 if (kvm_ishost(kd)) { 476 size = 0; 477 mib[0] = CTL_KERN; 478 mib[1] = KERN_PROC; 479 mib[2] = op; 480 mib[3] = arg; 481 st = sysctl(mib, miblen, NULL, &size, NULL, 0); 482 if (st == -1) { 483 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 484 return (0); 485 } 486 do { 487 size += size / 10; 488 kd->procbase = (struct kinfo_proc *) 489 _kvm_realloc(kd, kd->procbase, size); 490 if (kd->procbase == 0) 491 return (0); 492 st = sysctl(mib, miblen, kd->procbase, &size, NULL, 0); 493 } while (st == -1 && errno == ENOMEM); 494 if (st == -1) { 495 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 496 return (0); 497 } 498 if (size % sizeof(struct kinfo_proc) != 0) { 499 _kvm_err(kd, kd->program, 500 "proc size mismatch (%zd total, %zd chunks)", 501 size, sizeof(struct kinfo_proc)); 502 return (0); 503 } 504 nprocs = size / sizeof(struct kinfo_proc); 505 } else { 506 struct nlist nl[4], *p; 507 508 nl[0].n_name = "_nprocs"; 509 nl[1].n_name = "_procglob"; 510 nl[2].n_name = "_allproc_hsize"; 511 nl[3].n_name = 0; 512 513 if (kvm_nlist(kd, nl) != 0) { 514 for (p = nl; p->n_type != 0; ++p) 515 ; 516 _kvm_err(kd, kd->program, 517 "%s: no such symbol", p->n_name); 518 return (0); 519 } 520 if (KREAD(kd, nl[0].n_value, &nprocs)) { 521 _kvm_err(kd, kd->program, "can't read nprocs"); 522 return (0); 523 } 524 if (KREAD(kd, nl[2].n_value, &allproc_hsize)) { 525 _kvm_err(kd, kd->program, "can't read allproc_hsize"); 526 return (0); 527 } 528 nprocs = kvm_deadprocs(kd, op, arg, allproc_hsize); 529 #ifdef notdef 530 size = nprocs * sizeof(struct kinfo_proc); 531 (void)realloc(kd->procbase, size); 532 #endif 533 } 534 *cnt = nprocs; 535 return (kd->procbase); 536 } 537 538 void 539 _kvm_freeprocs(kvm_t *kd) 540 { 541 if (kd->procbase) { 542 free(kd->procbase); 543 kd->procbase = 0; 544 } 545 } 546 547 void * 548 _kvm_realloc(kvm_t *kd, void *p, size_t n) 549 { 550 void *np = (void *)realloc(p, n); 551 552 if (np == NULL) { 553 free(p); 554 _kvm_err(kd, kd->program, "out of memory"); 555 } 556 return (np); 557 } 558 559 #ifndef MAX 560 #define MAX(a, b) ((a) > (b) ? (a) : (b)) 561 #endif 562 563 /* 564 * Read in an argument vector from the user address space of process pid. 565 * addr if the user-space base address of narg null-terminated contiguous 566 * strings. This is used to read in both the command arguments and 567 * environment strings. Read at most maxcnt characters of strings. 568 */ 569 static char ** 570 kvm_argv(kvm_t *kd, pid_t pid, u_long addr, int narg, int maxcnt) 571 { 572 char *np, *cp, *ep, *ap; 573 u_long oaddr = -1; 574 u_long addr_min = VM_MIN_USER_ADDRESS; 575 u_long addr_max = VM_MAX_USER_ADDRESS; 576 int len, cc; 577 char **argv; 578 579 /* 580 * Check that there aren't an unreasonable number of agruments, 581 * and that the address is in user space. 582 */ 583 if (narg > 512 || addr < addr_min || addr >= addr_max) 584 return (0); 585 586 /* 587 * kd->argv : work space for fetching the strings from the target 588 * process's space, and is converted for returning to caller 589 */ 590 if (kd->argv == 0) { 591 /* 592 * Try to avoid reallocs. 593 */ 594 kd->argc = MAX(narg + 1, 32); 595 kd->argv = (char **)_kvm_malloc(kd, kd->argc * 596 sizeof(*kd->argv)); 597 if (kd->argv == 0) 598 return (0); 599 } else if (narg + 1 > kd->argc) { 600 kd->argc = MAX(2 * kd->argc, narg + 1); 601 kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * 602 sizeof(*kd->argv)); 603 if (kd->argv == 0) 604 return (0); 605 } 606 /* 607 * kd->argspc : returned to user, this is where the kd->argv 608 * arrays are left pointing to the collected strings. 609 */ 610 if (kd->argspc == 0) { 611 kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE); 612 if (kd->argspc == 0) 613 return (0); 614 kd->arglen = PAGE_SIZE; 615 } 616 /* 617 * kd->argbuf : used to pull in pages from the target process. 618 * the strings are copied out of here. 619 */ 620 if (kd->argbuf == 0) { 621 kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE); 622 if (kd->argbuf == 0) 623 return (0); 624 } 625 626 /* Pull in the target process'es argv vector */ 627 cc = sizeof(char *) * narg; 628 if (kvm_uread(kd, pid, addr, (char *)kd->argv, cc) != cc) 629 return (0); 630 /* 631 * ap : saved start address of string we're working on in kd->argspc 632 * np : pointer to next place to write in kd->argspc 633 * len: length of data in kd->argspc 634 * argv: pointer to the argv vector that we are hunting around the 635 * target process space for, and converting to addresses in 636 * our address space (kd->argspc). 637 */ 638 ap = np = kd->argspc; 639 argv = kd->argv; 640 len = 0; 641 /* 642 * Loop over pages, filling in the argument vector. 643 * Note that the argv strings could be pointing *anywhere* in 644 * the user address space and are no longer contiguous. 645 * Note that *argv is modified when we are going to fetch a string 646 * that crosses a page boundary. We copy the next part of the string 647 * into to "np" and eventually convert the pointer. 648 */ 649 while (argv < kd->argv + narg && *argv != NULL) { 650 651 /* get the address that the current argv string is on */ 652 addr = rounddown2((u_long)*argv, PAGE_SIZE); 653 654 /* is it the same page as the last one? */ 655 if (addr != oaddr) { 656 if (kvm_uread(kd, pid, addr, kd->argbuf, PAGE_SIZE) != 657 PAGE_SIZE) 658 return (0); 659 oaddr = addr; 660 } 661 662 /* offset within the page... kd->argbuf */ 663 addr = (u_long)*argv & (PAGE_SIZE - 1); 664 665 /* cp = start of string, cc = count of chars in this chunk */ 666 cp = kd->argbuf + addr; 667 cc = PAGE_SIZE - addr; 668 669 /* dont get more than asked for by user process */ 670 if (maxcnt > 0 && cc > maxcnt - len) 671 cc = maxcnt - len; 672 673 /* pointer to end of string if we found it in this page */ 674 ep = memchr(cp, '\0', cc); 675 if (ep != NULL) 676 cc = ep - cp + 1; 677 /* 678 * at this point, cc is the count of the chars that we are 679 * going to retrieve this time. we may or may not have found 680 * the end of it. (ep points to the null if the end is known) 681 */ 682 683 /* will we exceed the malloc/realloced buffer? */ 684 if (len + cc > kd->arglen) { 685 size_t off; 686 char **pp; 687 char *op = kd->argspc; 688 689 kd->arglen *= 2; 690 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, 691 kd->arglen); 692 if (kd->argspc == 0) 693 return (0); 694 /* 695 * Adjust argv pointers in case realloc moved 696 * the string space. 697 */ 698 off = kd->argspc - op; 699 for (pp = kd->argv; pp < argv; pp++) 700 *pp += off; 701 ap += off; 702 np += off; 703 } 704 /* np = where to put the next part of the string in kd->argspc*/ 705 /* np is kinda redundant.. could use "kd->argspc + len" */ 706 memcpy(np, cp, cc); 707 np += cc; /* inc counters */ 708 len += cc; 709 710 /* 711 * if end of string found, set the *argv pointer to the 712 * saved beginning of string, and advance. argv points to 713 * somewhere in kd->argv.. This is initially relative 714 * to the target process, but when we close it off, we set 715 * it to point in our address space. 716 */ 717 if (ep != NULL) { 718 *argv++ = ap; 719 ap = np; 720 } else { 721 /* update the address relative to the target process */ 722 *argv += cc; 723 } 724 725 if (maxcnt > 0 && len >= maxcnt) { 726 /* 727 * We're stopping prematurely. Terminate the 728 * current string. 729 */ 730 if (ep == NULL) { 731 *np = '\0'; 732 *argv++ = ap; 733 } 734 break; 735 } 736 } 737 /* Make sure argv is terminated. */ 738 *argv = NULL; 739 return (kd->argv); 740 } 741 742 static void 743 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 744 { 745 *addr = (u_long)p->ps_argvstr; 746 *n = p->ps_nargvstr; 747 } 748 749 static void 750 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 751 { 752 *addr = (u_long)p->ps_envstr; 753 *n = p->ps_nenvstr; 754 } 755 756 /* 757 * Determine if the proc indicated by p is still active. 758 * This test is not 100% foolproof in theory, but chances of 759 * being wrong are very low. 760 */ 761 static int 762 proc_verify(const struct kinfo_proc *p) 763 { 764 struct kinfo_proc kp; 765 int mib[4]; 766 size_t len; 767 int error; 768 769 mib[0] = CTL_KERN; 770 mib[1] = KERN_PROC; 771 mib[2] = KERN_PROC_PID; 772 mib[3] = p->kp_pid; 773 774 len = sizeof(kp); 775 error = sysctl(mib, 4, &kp, &len, NULL, 0); 776 if (error) 777 return (0); 778 779 error = (p->kp_pid == kp.kp_pid && 780 (kp.kp_stat != SZOMB || p->kp_stat == SZOMB)); 781 return (error); 782 } 783 784 static char ** 785 kvm_doargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr, 786 void (*info)(struct ps_strings *, u_long *, int *)) 787 { 788 char **ap; 789 u_long addr; 790 int cnt; 791 static struct ps_strings arginfo; 792 static u_long ps_strings; 793 size_t len; 794 795 if (ps_strings == 0) { 796 len = sizeof(ps_strings); 797 if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL, 798 0) == -1) 799 ps_strings = PS_STRINGS; 800 } 801 802 /* 803 * Pointers are stored at the top of the user stack. 804 */ 805 if (kp->kp_stat == SZOMB || 806 kvm_uread(kd, kp->kp_pid, ps_strings, (char *)&arginfo, 807 sizeof(arginfo)) != sizeof(arginfo)) 808 return (0); 809 810 (*info)(&arginfo, &addr, &cnt); 811 if (cnt == 0) 812 return (0); 813 ap = kvm_argv(kd, kp->kp_pid, addr, cnt, nchr); 814 /* 815 * For live kernels, make sure this process didn't go away. 816 */ 817 if (ap != NULL && (kvm_ishost(kd) || kvm_isvkernel(kd)) && 818 !proc_verify(kp)) 819 ap = NULL; 820 return (ap); 821 } 822 823 /* 824 * Get the command args. This code is now machine independent. 825 */ 826 char ** 827 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 828 { 829 int oid[8]; 830 int i; 831 size_t bufsz; 832 static unsigned long buflen; 833 static char *buf, *p; 834 static char **bufp; 835 static int argc; 836 837 if (!kvm_ishost(kd)) { /* XXX: vkernels */ 838 _kvm_err(kd, kd->program, 839 "cannot read user space from dead kernel"); 840 return (0); 841 } 842 843 if (!buflen) { 844 bufsz = sizeof(buflen); 845 i = sysctlbyname("kern.ps_arg_cache_limit", 846 &buflen, &bufsz, NULL, 0); 847 if (i == -1) { 848 buflen = 0; 849 } else { 850 buf = malloc(buflen); 851 if (buf == NULL) 852 buflen = 0; 853 argc = 32; 854 bufp = malloc(sizeof(char *) * argc); 855 } 856 } 857 if (buf != NULL) { 858 oid[0] = CTL_KERN; 859 oid[1] = KERN_PROC; 860 oid[2] = KERN_PROC_ARGS; 861 oid[3] = kp->kp_pid; 862 oid[4] = kp->kp_lwp.kl_tid; 863 864 /* 865 * sysctl can take a pid in 5.7 or earlier. In late 866 * 5.7 the sysctl can take a pid (4 args) or pid + tid 867 * (5 args). 868 */ 869 i = -1; 870 if (kp->kp_lwp.kl_tid > 0) { 871 bufsz = buflen; 872 i = sysctl(oid, 5, buf, &bufsz, 0, 0); 873 } 874 if (i < 0) { 875 bufsz = buflen; 876 i = sysctl(oid, 4, buf, &bufsz, 0, 0); 877 } 878 879 if (i == 0 && bufsz > 0) { 880 i = 0; 881 p = buf; 882 do { 883 bufp[i++] = p; 884 p += strlen(p) + 1; 885 if (i >= argc) { 886 argc += argc; 887 bufp = realloc(bufp, 888 sizeof(char *) * argc); 889 } 890 } while (p < buf + bufsz); 891 bufp[i++] = NULL; 892 return (bufp); 893 } 894 } 895 if (kp->kp_flags & P_SYSTEM) 896 return (NULL); 897 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 898 } 899 900 char ** 901 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 902 { 903 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 904 } 905 906 /* 907 * Read from user space. The user context is given by pid. 908 */ 909 ssize_t 910 kvm_uread(kvm_t *kd, pid_t pid, u_long uva, char *buf, size_t len) 911 { 912 char *cp; 913 char procfile[MAXPATHLEN]; 914 ssize_t amount; 915 int fd; 916 917 if (!kvm_ishost(kd)) { /* XXX: vkernels */ 918 _kvm_err(kd, kd->program, 919 "cannot read user space from dead kernel"); 920 return (0); 921 } 922 923 sprintf(procfile, "/proc/%d/mem", pid); 924 fd = open(procfile, O_RDONLY, 0); 925 if (fd < 0) { 926 _kvm_err(kd, kd->program, "cannot open %s", procfile); 927 close(fd); 928 return (0); 929 } 930 931 cp = buf; 932 while (len > 0) { 933 errno = 0; 934 if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) { 935 _kvm_err(kd, kd->program, "invalid address (%lx) in %s", 936 uva, procfile); 937 break; 938 } 939 amount = read(fd, cp, len); 940 if (amount < 0) { 941 _kvm_syserr(kd, kd->program, "error reading %s", 942 procfile); 943 break; 944 } 945 if (amount == 0) { 946 _kvm_err(kd, kd->program, "EOF reading %s", procfile); 947 break; 948 } 949 cp += amount; 950 uva += amount; 951 len -= amount; 952 } 953 954 close(fd); 955 return ((ssize_t)(cp - buf)); 956 } 957