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