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