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 devid_from_dev(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 devid_from_dev(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 devid_from_dev(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, long procglob) 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 = procglob + 437 sizeof(struct procglob) * n + 438 offsetof(struct procglob, allproc); 439 nextoff = a_allproc; 440 if (KREAD(kd, (u_long)nextoff, pl[n])) { 441 _kvm_err(kd, kd->program, "can't read proclist at 0x%lx", 442 a_allproc); 443 return (-1); 444 } 445 446 /* Ignore empty proclists */ 447 if (LIST_EMPTY(pl[n])) 448 continue; 449 450 bp = kd->procbase + cnt; 451 p = pl[n]->lh_first; 452 partcnt = kvm_proclist(kd, what, arg, p, bp); 453 if (partcnt < 0) { 454 free(pl[n]); 455 return (partcnt); 456 } 457 458 cnt += partcnt; 459 free(pl[n]); 460 } 461 462 return (cnt); 463 } 464 465 struct kinfo_proc * 466 kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt) 467 { 468 int mib[4], st, nprocs, allproc_hsize; 469 int miblen = ((op & ~KERN_PROC_FLAGMASK) == KERN_PROC_ALL) ? 3 : 4; 470 size_t size; 471 472 if (kd->procbase != NULL) { 473 free(kd->procbase); 474 kd->procbase = NULL; 475 } 476 if (kvm_ishost(kd)) { 477 size = 0; 478 mib[0] = CTL_KERN; 479 mib[1] = KERN_PROC; 480 mib[2] = op; 481 mib[3] = arg; 482 st = sysctl(mib, miblen, NULL, &size, NULL, 0); 483 if (st == -1) { 484 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 485 return (0); 486 } 487 do { 488 size += size / 10; 489 kd->procbase = (struct kinfo_proc *) 490 _kvm_realloc(kd, kd->procbase, size); 491 if (kd->procbase == 0) 492 return (0); 493 st = sysctl(mib, miblen, kd->procbase, &size, NULL, 0); 494 } while (st == -1 && errno == ENOMEM); 495 if (st == -1) { 496 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 497 return (0); 498 } 499 if (size % sizeof(struct kinfo_proc) != 0) { 500 _kvm_err(kd, kd->program, 501 "proc size mismatch (%zd total, %zd chunks)", 502 size, sizeof(struct kinfo_proc)); 503 return (0); 504 } 505 nprocs = size / sizeof(struct kinfo_proc); 506 } else { 507 struct nlist nl[4], *p; 508 u_long procglob; 509 510 nl[0].n_name = "_nprocs"; 511 nl[1].n_name = "_procglob"; 512 nl[2].n_name = "_allproc_hsize"; 513 nl[3].n_name = 0; 514 515 if (kvm_nlist(kd, nl) != 0) { 516 for (p = nl; p->n_type != 0; ++p) 517 ; 518 _kvm_err(kd, kd->program, 519 "%s: no such symbol", p->n_name); 520 return (0); 521 } 522 if (KREAD(kd, nl[0].n_value, &nprocs)) { 523 _kvm_err(kd, kd->program, "can't read nprocs"); 524 return (0); 525 } 526 if (KREAD(kd, nl[2].n_value, &allproc_hsize)) { 527 _kvm_err(kd, kd->program, "can't read allproc_hsize"); 528 return (0); 529 } 530 procglob = nl[1].n_value; 531 nprocs = kvm_deadprocs(kd, op, arg, allproc_hsize, procglob); 532 #ifdef notdef 533 size = nprocs * sizeof(struct kinfo_proc); 534 (void)realloc(kd->procbase, size); 535 #endif 536 } 537 *cnt = nprocs; 538 return (kd->procbase); 539 } 540 541 void 542 _kvm_freeprocs(kvm_t *kd) 543 { 544 if (kd->procbase) { 545 free(kd->procbase); 546 kd->procbase = 0; 547 } 548 } 549 550 void * 551 _kvm_realloc(kvm_t *kd, void *p, size_t n) 552 { 553 void *np = (void *)realloc(p, n); 554 555 if (np == NULL) { 556 free(p); 557 _kvm_err(kd, kd->program, "out of memory"); 558 } 559 return (np); 560 } 561 562 #ifndef MAX 563 #define MAX(a, b) ((a) > (b) ? (a) : (b)) 564 #endif 565 566 /* 567 * Read in an argument vector from the user address space of process pid. 568 * addr if the user-space base address of narg null-terminated contiguous 569 * strings. This is used to read in both the command arguments and 570 * environment strings. Read at most maxcnt characters of strings. 571 */ 572 static char ** 573 kvm_argv(kvm_t *kd, pid_t pid, u_long addr, int narg, int maxcnt) 574 { 575 char *np, *cp, *ep, *ap; 576 u_long oaddr = -1; 577 u_long addr_min = VM_MIN_USER_ADDRESS; 578 u_long addr_max = VM_MAX_USER_ADDRESS; 579 int len, cc; 580 char **argv; 581 582 /* 583 * Check that there aren't an unreasonable number of agruments, 584 * and that the address is in user space. 585 */ 586 if (narg > 512 || addr < addr_min || addr >= addr_max) 587 return (0); 588 589 /* 590 * kd->argv : work space for fetching the strings from the target 591 * process's space, and is converted for returning to caller 592 */ 593 if (kd->argv == 0) { 594 /* 595 * Try to avoid reallocs. 596 */ 597 kd->argc = MAX(narg + 1, 32); 598 kd->argv = (char **)_kvm_malloc(kd, kd->argc * 599 sizeof(*kd->argv)); 600 if (kd->argv == 0) 601 return (0); 602 } else if (narg + 1 > kd->argc) { 603 kd->argc = MAX(2 * kd->argc, narg + 1); 604 kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * 605 sizeof(*kd->argv)); 606 if (kd->argv == 0) 607 return (0); 608 } 609 /* 610 * kd->argspc : returned to user, this is where the kd->argv 611 * arrays are left pointing to the collected strings. 612 */ 613 if (kd->argspc == 0) { 614 kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE); 615 if (kd->argspc == 0) 616 return (0); 617 kd->arglen = PAGE_SIZE; 618 } 619 /* 620 * kd->argbuf : used to pull in pages from the target process. 621 * the strings are copied out of here. 622 */ 623 if (kd->argbuf == 0) { 624 kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE); 625 if (kd->argbuf == 0) 626 return (0); 627 } 628 629 /* Pull in the target process'es argv vector */ 630 cc = sizeof(char *) * narg; 631 if (kvm_uread(kd, pid, addr, (char *)kd->argv, cc) != cc) 632 return (0); 633 /* 634 * ap : saved start address of string we're working on in kd->argspc 635 * np : pointer to next place to write in kd->argspc 636 * len: length of data in kd->argspc 637 * argv: pointer to the argv vector that we are hunting around the 638 * target process space for, and converting to addresses in 639 * our address space (kd->argspc). 640 */ 641 ap = np = kd->argspc; 642 argv = kd->argv; 643 len = 0; 644 /* 645 * Loop over pages, filling in the argument vector. 646 * Note that the argv strings could be pointing *anywhere* in 647 * the user address space and are no longer contiguous. 648 * Note that *argv is modified when we are going to fetch a string 649 * that crosses a page boundary. We copy the next part of the string 650 * into to "np" and eventually convert the pointer. 651 */ 652 while (argv < kd->argv + narg && *argv != NULL) { 653 654 /* get the address that the current argv string is on */ 655 addr = rounddown2((u_long)*argv, PAGE_SIZE); 656 657 /* is it the same page as the last one? */ 658 if (addr != oaddr) { 659 if (kvm_uread(kd, pid, addr, kd->argbuf, PAGE_SIZE) != 660 PAGE_SIZE) 661 return (0); 662 oaddr = addr; 663 } 664 665 /* offset within the page... kd->argbuf */ 666 addr = (u_long)*argv & (PAGE_SIZE - 1); 667 668 /* cp = start of string, cc = count of chars in this chunk */ 669 cp = kd->argbuf + addr; 670 cc = PAGE_SIZE - addr; 671 672 /* dont get more than asked for by user process */ 673 if (maxcnt > 0 && cc > maxcnt - len) 674 cc = maxcnt - len; 675 676 /* pointer to end of string if we found it in this page */ 677 ep = memchr(cp, '\0', cc); 678 if (ep != NULL) 679 cc = ep - cp + 1; 680 /* 681 * at this point, cc is the count of the chars that we are 682 * going to retrieve this time. we may or may not have found 683 * the end of it. (ep points to the null if the end is known) 684 */ 685 686 /* will we exceed the malloc/realloced buffer? */ 687 if (len + cc > kd->arglen) { 688 size_t off; 689 char **pp; 690 char *op = kd->argspc; 691 692 kd->arglen *= 2; 693 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, 694 kd->arglen); 695 if (kd->argspc == 0) 696 return (0); 697 /* 698 * Adjust argv pointers in case realloc moved 699 * the string space. 700 */ 701 off = kd->argspc - op; 702 for (pp = kd->argv; pp < argv; pp++) 703 *pp += off; 704 ap += off; 705 np += off; 706 } 707 /* np = where to put the next part of the string in kd->argspc*/ 708 /* np is kinda redundant.. could use "kd->argspc + len" */ 709 memcpy(np, cp, cc); 710 np += cc; /* inc counters */ 711 len += cc; 712 713 /* 714 * if end of string found, set the *argv pointer to the 715 * saved beginning of string, and advance. argv points to 716 * somewhere in kd->argv.. This is initially relative 717 * to the target process, but when we close it off, we set 718 * it to point in our address space. 719 */ 720 if (ep != NULL) { 721 *argv++ = ap; 722 ap = np; 723 } else { 724 /* update the address relative to the target process */ 725 *argv += cc; 726 } 727 728 if (maxcnt > 0 && len >= maxcnt) { 729 /* 730 * We're stopping prematurely. Terminate the 731 * current string. 732 */ 733 if (ep == NULL) { 734 *np = '\0'; 735 *argv++ = ap; 736 } 737 break; 738 } 739 } 740 /* Make sure argv is terminated. */ 741 *argv = NULL; 742 return (kd->argv); 743 } 744 745 static void 746 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 747 { 748 *addr = (u_long)p->ps_argvstr; 749 *n = p->ps_nargvstr; 750 } 751 752 static void 753 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 754 { 755 *addr = (u_long)p->ps_envstr; 756 *n = p->ps_nenvstr; 757 } 758 759 /* 760 * Determine if the proc indicated by p is still active. 761 * This test is not 100% foolproof in theory, but chances of 762 * being wrong are very low. 763 */ 764 static int 765 proc_verify(const struct kinfo_proc *p) 766 { 767 struct kinfo_proc kp; 768 int mib[4]; 769 size_t len; 770 int error; 771 772 mib[0] = CTL_KERN; 773 mib[1] = KERN_PROC; 774 mib[2] = KERN_PROC_PID; 775 mib[3] = p->kp_pid; 776 777 len = sizeof(kp); 778 error = sysctl(mib, 4, &kp, &len, NULL, 0); 779 if (error) 780 return (0); 781 782 error = (p->kp_pid == kp.kp_pid && 783 (kp.kp_stat != SZOMB || p->kp_stat == SZOMB)); 784 return (error); 785 } 786 787 static char ** 788 kvm_doargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr, 789 void (*info)(struct ps_strings *, u_long *, int *)) 790 { 791 char **ap; 792 u_long addr; 793 int cnt; 794 static struct ps_strings arginfo; 795 static u_long ps_strings; 796 size_t len; 797 798 if (ps_strings == 0) { 799 len = sizeof(ps_strings); 800 if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL, 801 0) == -1) 802 ps_strings = PS_STRINGS; 803 } 804 805 /* 806 * Pointers are stored at the top of the user stack. 807 */ 808 if (kp->kp_stat == SZOMB || 809 kvm_uread(kd, kp->kp_pid, ps_strings, (char *)&arginfo, 810 sizeof(arginfo)) != sizeof(arginfo)) 811 return (0); 812 813 (*info)(&arginfo, &addr, &cnt); 814 if (cnt == 0) 815 return (0); 816 ap = kvm_argv(kd, kp->kp_pid, addr, cnt, nchr); 817 /* 818 * For live kernels, make sure this process didn't go away. 819 */ 820 if (ap != NULL && (kvm_ishost(kd) || kvm_isvkernel(kd)) && 821 !proc_verify(kp)) 822 ap = NULL; 823 return (ap); 824 } 825 826 /* 827 * Get the command args. This code is now machine independent. 828 */ 829 char ** 830 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 831 { 832 int oid[8]; 833 int i; 834 size_t bufsz; 835 static unsigned long buflen; 836 static char *buf, *p; 837 static char **bufp; 838 static int argc; 839 840 if (!kvm_ishost(kd)) { /* XXX: vkernels */ 841 _kvm_err(kd, kd->program, 842 "cannot read user space from dead kernel"); 843 return (0); 844 } 845 846 if (!buflen) { 847 bufsz = sizeof(buflen); 848 i = sysctlbyname("kern.ps_arg_cache_limit", 849 &buflen, &bufsz, NULL, 0); 850 if (i == -1) { 851 buflen = 0; 852 } else { 853 buf = malloc(buflen); 854 if (buf == NULL) 855 buflen = 0; 856 argc = 32; 857 bufp = malloc(sizeof(char *) * argc); 858 } 859 } 860 if (buf != NULL) { 861 oid[0] = CTL_KERN; 862 oid[1] = KERN_PROC; 863 oid[2] = KERN_PROC_ARGS; 864 oid[3] = kp->kp_pid; 865 oid[4] = kp->kp_lwp.kl_tid; 866 867 /* 868 * sysctl can take a pid in 5.7 or earlier. In late 869 * 5.7 the sysctl can take a pid (4 args) or pid + tid 870 * (5 args). 871 */ 872 i = -1; 873 if (kp->kp_lwp.kl_tid > 0) { 874 bufsz = buflen; 875 i = sysctl(oid, 5, buf, &bufsz, 0, 0); 876 } 877 if (i < 0) { 878 bufsz = buflen; 879 i = sysctl(oid, 4, buf, &bufsz, 0, 0); 880 } 881 882 if (i == 0 && bufsz > 0) { 883 i = 0; 884 p = buf; 885 do { 886 bufp[i++] = p; 887 p += strlen(p) + 1; 888 if (i >= argc) { 889 argc += argc; 890 bufp = realloc(bufp, 891 sizeof(char *) * argc); 892 } 893 } while (p < buf + bufsz); 894 bufp[i++] = NULL; 895 return (bufp); 896 } 897 } 898 if (kp->kp_flags & P_SYSTEM) 899 return (NULL); 900 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 901 } 902 903 char ** 904 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 905 { 906 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 907 } 908 909 /* 910 * Read from user space. The user context is given by pid. 911 */ 912 ssize_t 913 kvm_uread(kvm_t *kd, pid_t pid, u_long uva, char *buf, size_t len) 914 { 915 char *cp; 916 char procfile[MAXPATHLEN]; 917 ssize_t amount; 918 int fd; 919 920 if (!kvm_ishost(kd)) { /* XXX: vkernels */ 921 _kvm_err(kd, kd->program, 922 "cannot read user space from dead kernel"); 923 return (0); 924 } 925 926 sprintf(procfile, "/proc/%d/mem", pid); 927 fd = open(procfile, O_RDONLY, 0); 928 if (fd < 0) { 929 _kvm_err(kd, kd->program, "cannot open %s", procfile); 930 close(fd); 931 return (0); 932 } 933 934 cp = buf; 935 while (len > 0) { 936 errno = 0; 937 if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) { 938 _kvm_err(kd, kd->program, "invalid address (%lx) in %s", 939 uva, procfile); 940 break; 941 } 942 amount = read(fd, cp, len); 943 if (amount < 0) { 944 _kvm_syserr(kd, kd->program, "error reading %s", 945 procfile); 946 break; 947 } 948 if (amount == 0) { 949 _kvm_err(kd, kd->program, "EOF reading %s", procfile); 950 break; 951 } 952 cp += amount; 953 uva += amount; 954 len -= amount; 955 } 956 957 close(fd); 958 return ((ssize_t)(cp - buf)); 959 } 960