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. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * $FreeBSD: src/lib/libkvm/kvm_proc.c,v 1.25.2.3 2002/08/24 07:27:46 kris Exp $ 38 * $DragonFly: src/lib/libkvm/kvm_proc.c,v 1.17 2007/08/15 19:37:52 dillon Exp $ 39 * 40 * @(#)kvm_proc.c 8.3 (Berkeley) 9/23/93 41 */ 42 43 /* 44 * Proc traversal interface for kvm. ps and w are (probably) the exclusive 45 * users of this code, so we've factored it out into a separate module. 46 * Thus, we keep this grunge out of the other kvm applications (i.e., 47 * most other applications are interested only in open/close/read/nlist). 48 */ 49 50 #include <sys/user.h> /* MUST BE FIRST */ 51 #include <sys/conf.h> 52 #include <sys/param.h> 53 #include <sys/proc.h> 54 #include <sys/exec.h> 55 #include <sys/stat.h> 56 #include <sys/globaldata.h> 57 #include <sys/ioctl.h> 58 #include <sys/tty.h> 59 #include <sys/file.h> 60 #include <sys/jail.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <unistd.h> 64 #include <nlist.h> 65 #include <kvm.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_param.h> 69 #include <vm/swap_pager.h> 70 71 #include <sys/sysctl.h> 72 73 #include <limits.h> 74 #include <memory.h> 75 #include <paths.h> 76 77 #include "kvm_private.h" 78 79 #if used 80 static char * 81 kvm_readswap(kvm_t *kd, const struct proc *p, u_long va, u_long *cnt) 82 { 83 #if defined(__FreeBSD__) || defined(__DragonFly__) 84 /* XXX Stubbed out, our vm system is differnet */ 85 _kvm_err(kd, kd->program, "kvm_readswap not implemented"); 86 return(0); 87 #endif 88 } 89 #endif 90 91 #define KREAD(kd, addr, obj) \ 92 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 93 #define KREADSTR(kd, addr) \ 94 kvm_readstr(kd, (u_long)addr, NULL, NULL) 95 96 static struct kinfo_proc * 97 kinfo_resize_proc(kvm_t *kd, struct kinfo_proc *bp) 98 { 99 if (bp < kd->procend) 100 return bp; 101 102 size_t pos = bp - kd->procend; 103 size_t size = kd->procend - kd->procbase; 104 105 if (size == 0) 106 size = 8; 107 else 108 size *= 2; 109 kd->procbase = _kvm_realloc(kd, kd->procbase, sizeof(*bp) * size); 110 if (kd->procbase == NULL) 111 return NULL; 112 kd->procend = kd->procbase + size; 113 bp = kd->procbase + pos; 114 return bp; 115 } 116 117 /* 118 * note: this function is also used by /usr/src/sys/kern/kern_kinfo.c as 119 * compiled by userland. 120 */ 121 dev_t 122 dev2udev(cdev_t dev) 123 { 124 if (dev == NULL) 125 return NOUDEV; 126 if ((dev->si_umajor & 0xffffff00) || 127 (dev->si_uminor & 0x0000ff00)) { 128 return NOUDEV; 129 } 130 return((dev->si_umajor << 8) | dev->si_uminor); 131 } 132 133 /* 134 * Helper routine which traverses the left hand side of a red-black sub-tree. 135 */ 136 static uintptr_t 137 kvm_lwptraverse(kvm_t *kd, struct lwp *lwp, uintptr_t lwppos) 138 { 139 for (;;) { 140 if (KREAD(kd, lwppos, lwp)) { 141 _kvm_err(kd, kd->program, "can't read lwp at %p", 142 (void *)lwppos); 143 return ((uintptr_t)-1); 144 } 145 if (lwp->u.lwp_rbnode.rbe_left == NULL) 146 break; 147 lwppos = (uintptr_t)lwp->u.lwp_rbnode.rbe_left; 148 } 149 return(lwppos); 150 } 151 152 /* 153 * Iterate LWPs in a process. 154 * 155 * The first lwp in a red-black tree is a left-side traversal of the tree. 156 */ 157 static uintptr_t 158 kvm_firstlwp(kvm_t *kd, struct lwp *lwp, struct proc *proc) 159 { 160 return(kvm_lwptraverse(kd, lwp, (uintptr_t)proc->p_lwp_tree.rbh_root)); 161 } 162 163 /* 164 * If the current element is the left side of the parent the next element 165 * will be a left side traversal of the parent's right side. If the parent 166 * has no right side the next element will be the parent. 167 * 168 * If the current element is the right side of the parent the next element 169 * is the parent. 170 * 171 * If the parent is NULL we are done. 172 */ 173 static uintptr_t 174 kvm_nextlwp(kvm_t *kd, uintptr_t lwppos, struct lwp *lwp, struct proc *proc) 175 { 176 uintptr_t nextpos; 177 178 nextpos = (uintptr_t)lwp->u.lwp_rbnode.rbe_parent; 179 if (nextpos) { 180 if (KREAD(kd, nextpos, lwp)) { 181 _kvm_err(kd, kd->program, "can't read lwp at %p", 182 (void *)lwppos); 183 return ((uintptr_t)-1); 184 } 185 if (lwppos == (uintptr_t)lwp->u.lwp_rbnode.rbe_left) { 186 /* 187 * If we had gone down the left side the next element 188 * is a left hand traversal of the parent's right 189 * side, or the parent itself if there is no right 190 * side. 191 */ 192 lwppos = (uintptr_t)lwp->u.lwp_rbnode.rbe_right; 193 if (lwppos) 194 nextpos = kvm_lwptraverse(kd, lwp, lwppos); 195 } else { 196 /* 197 * If we had gone down the right side the next 198 * element is the parent. 199 */ 200 /* nextpos = nextpos */ 201 } 202 } 203 return(nextpos); 204 } 205 206 /* 207 * Read proc's from memory file into buffer bp, which has space to hold 208 * at most maxcnt procs. 209 */ 210 static int 211 kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p, 212 struct kinfo_proc *bp) 213 { 214 struct pgrp pgrp; 215 struct pgrp tpgrp; 216 struct globaldata gdata; 217 struct session sess; 218 struct session tsess; 219 struct tty tty; 220 struct proc proc; 221 struct ucred ucred; 222 struct thread thread; 223 struct proc pproc; 224 struct cdev cdev; 225 struct vmspace vmspace; 226 struct prison prison; 227 struct sigacts sigacts; 228 struct lwp lwp; 229 uintptr_t lwppos; 230 int count; 231 char *wmesg; 232 233 count = 0; 234 235 for (; p != NULL; p = proc.p_list.le_next) { 236 if (KREAD(kd, (u_long)p, &proc)) { 237 _kvm_err(kd, kd->program, "can't read proc at %x", p); 238 return (-1); 239 } 240 if (KREAD(kd, (u_long)proc.p_ucred, &ucred)) { 241 _kvm_err(kd, kd->program, "can't read ucred at %p", 242 proc.p_ucred); 243 return (-1); 244 } 245 proc.p_ucred = &ucred; 246 247 switch(what & ~KERN_PROC_FLAGMASK) { 248 249 case KERN_PROC_PID: 250 if (proc.p_pid != (pid_t)arg) 251 continue; 252 break; 253 254 case KERN_PROC_UID: 255 if (ucred.cr_uid != (uid_t)arg) 256 continue; 257 break; 258 259 case KERN_PROC_RUID: 260 if (ucred.cr_ruid != (uid_t)arg) 261 continue; 262 break; 263 } 264 265 if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) { 266 _kvm_err(kd, kd->program, "can't read pgrp at %x", 267 proc.p_pgrp); 268 return (-1); 269 } 270 proc.p_pgrp = &pgrp; 271 if (proc.p_pptr) { 272 if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) { 273 _kvm_err(kd, kd->program, "can't read pproc at %x", 274 proc.p_pptr); 275 return (-1); 276 } 277 proc.p_pptr = &pproc; 278 } 279 280 if (proc.p_sigacts) { 281 if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) { 282 _kvm_err(kd, kd->program, 283 "can't read sigacts at %p", 284 proc.p_sigacts); 285 return (-1); 286 } 287 proc.p_sigacts = &sigacts; 288 } 289 290 if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) { 291 _kvm_err(kd, kd->program, "can't read session at %x", 292 pgrp.pg_session); 293 return (-1); 294 } 295 pgrp.pg_session = &sess; 296 297 if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) { 298 if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) { 299 _kvm_err(kd, kd->program, 300 "can't read tty at %x", sess.s_ttyp); 301 return (-1); 302 } 303 sess.s_ttyp = &tty; 304 if (tty.t_dev && tty.t_dev != NULL) { 305 if (KREAD(kd, (u_long)tty.t_dev, &cdev)) 306 tty.t_dev = NULL; 307 else 308 tty.t_dev = &cdev; 309 } 310 if (tty.t_pgrp != NULL) { 311 if (KREAD(kd, (u_long)tty.t_pgrp, &tpgrp)) { 312 _kvm_err(kd, kd->program, 313 "can't read tpgrp at %x", 314 tty.t_pgrp); 315 return (-1); 316 } 317 tty.t_pgrp = &tpgrp; 318 } 319 if (tty.t_session != NULL) { 320 if (KREAD(kd, (u_long)tty.t_session, &tsess)) { 321 _kvm_err(kd, kd->program, 322 "can't read tsess at %p", 323 tty.t_session); 324 return (-1); 325 } 326 tty.t_session = &tsess; 327 } 328 } 329 330 if (KREAD(kd, (u_long)proc.p_vmspace, &vmspace)) { 331 _kvm_err(kd, kd->program, "can't read vmspace at %p", 332 proc.p_vmspace); 333 return (-1); 334 } 335 proc.p_vmspace = &vmspace; 336 337 if (ucred.cr_prison != NULL) { 338 if (KREAD(kd, (u_long)ucred.cr_prison, &prison)) { 339 _kvm_err(kd, kd->program, "can't read prison at %p", 340 ucred.cr_prison); 341 return (-1); 342 } 343 ucred.cr_prison = &prison; 344 } 345 346 switch (what & ~KERN_PROC_FLAGMASK) { 347 348 case KERN_PROC_PGRP: 349 if (proc.p_pgrp->pg_id != (pid_t)arg) 350 continue; 351 break; 352 353 case KERN_PROC_TTY: 354 if ((proc.p_flag & P_CONTROLT) == 0 || 355 dev2udev(proc.p_pgrp->pg_session->s_ttyp->t_dev) 356 != (dev_t)arg) 357 continue; 358 break; 359 } 360 361 if ((bp = kinfo_resize_proc(kd, bp)) == NULL) 362 return (-1); 363 fill_kinfo_proc(&proc, bp); 364 bp->kp_paddr = (uintptr_t)p; 365 366 lwppos = kvm_firstlwp(kd, &lwp, &proc); 367 if (lwppos == 0) { 368 bp++; /* Just export the proc then */ 369 count++; 370 } 371 while (lwppos && lwppos != (uintptr_t)-1) { 372 if (p != lwp.lwp_proc) { 373 _kvm_err(kd, kd->program, "lwp has wrong parent"); 374 return (-1); 375 } 376 lwp.lwp_proc = &proc; 377 if (KREAD(kd, (u_long)lwp.lwp_thread, &thread)) { 378 _kvm_err(kd, kd->program, "can't read thread at %x", 379 lwp.lwp_thread); 380 return (-1); 381 } 382 lwp.lwp_thread = &thread; 383 384 if (thread.td_gd) { 385 if (KREAD(kd, (u_long)thread.td_gd, &gdata)) { 386 _kvm_err(kd, kd->program, "can't read" 387 " gd at %p", 388 thread.td_gd); 389 return(-1); 390 } 391 thread.td_gd = &gdata; 392 } 393 if (thread.td_wmesg) { 394 wmesg = (void *)KREADSTR(kd, thread.td_wmesg); 395 if (wmesg == NULL) { 396 _kvm_err(kd, kd->program, "can't read" 397 " wmesg %p", 398 thread.td_wmesg); 399 return(-1); 400 } 401 thread.td_wmesg = wmesg; 402 } else { 403 wmesg = NULL; 404 } 405 406 if ((bp = kinfo_resize_proc(kd, bp)) == NULL) 407 return (-1); 408 fill_kinfo_proc(&proc, bp); 409 fill_kinfo_lwp(&lwp, &bp->kp_lwp); 410 bp->kp_paddr = (uintptr_t)p; 411 bp++; 412 count++; 413 if (wmesg) 414 free(wmesg); 415 if ((what & KERN_PROC_FLAG_LWP) == 0) 416 break; 417 lwppos = kvm_nextlwp(kd, lwppos, &lwp, &proc); 418 } 419 if (lwppos == (uintptr_t)-1) 420 return(-1); 421 } 422 return (count); 423 } 424 425 /* 426 * Build proc info array by reading in proc list from a crash dump. 427 * We reallocate kd->procbase as necessary. 428 */ 429 static int 430 kvm_deadprocs(kvm_t *kd, int what, int arg, u_long a_allproc, 431 u_long a_zombproc) 432 { 433 struct kinfo_proc *bp = kd->procbase; 434 int acnt, zcnt; 435 struct proc *p; 436 437 if (KREAD(kd, a_allproc, &p)) { 438 _kvm_err(kd, kd->program, "cannot read allproc"); 439 return (-1); 440 } 441 acnt = kvm_proclist(kd, what, arg, p, bp); 442 if (acnt < 0) 443 return (acnt); 444 445 if (KREAD(kd, a_zombproc, &p)) { 446 _kvm_err(kd, kd->program, "cannot read zombproc"); 447 return (-1); 448 } 449 zcnt = kvm_proclist(kd, what, arg, p, bp + acnt); 450 if (zcnt < 0) 451 zcnt = 0; 452 453 return (acnt + zcnt); 454 } 455 456 struct kinfo_proc * 457 kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt) 458 { 459 int mib[4], st, nprocs; 460 int miblen = ((op & ~KERN_PROC_FLAGMASK) == KERN_PROC_ALL) ? 3 : 4; 461 size_t size; 462 463 if (kd->procbase != 0) { 464 free((void *)kd->procbase); 465 /* 466 * Clear this pointer in case this call fails. Otherwise, 467 * kvm_close() will free it again. 468 */ 469 kd->procbase = 0; 470 } 471 if (ISALIVE(kd)) { 472 size = 0; 473 mib[0] = CTL_KERN; 474 mib[1] = KERN_PROC; 475 mib[2] = op; 476 mib[3] = arg; 477 st = sysctl(mib, miblen, NULL, &size, NULL, 0); 478 if (st == -1) { 479 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 480 return (0); 481 } 482 do { 483 size += size / 10; 484 kd->procbase = (struct kinfo_proc *) 485 _kvm_realloc(kd, kd->procbase, size); 486 if (kd->procbase == 0) 487 return (0); 488 st = sysctl(mib, miblen, kd->procbase, &size, NULL, 0); 489 } while (st == -1 && errno == ENOMEM); 490 if (st == -1) { 491 _kvm_syserr(kd, kd->program, "kvm_getprocs"); 492 return (0); 493 } 494 if (size % sizeof(struct kinfo_proc) != 0) { 495 _kvm_err(kd, kd->program, 496 "proc size mismatch (%d total, %d chunks)", 497 size, sizeof(struct kinfo_proc)); 498 return (0); 499 } 500 nprocs = size / sizeof(struct kinfo_proc); 501 } else { 502 struct nlist nl[4], *p; 503 504 nl[0].n_name = "_nprocs"; 505 nl[1].n_name = "_allproc"; 506 nl[2].n_name = "_zombproc"; 507 nl[3].n_name = 0; 508 509 if (kvm_nlist(kd, nl) != 0) { 510 for (p = nl; p->n_type != 0; ++p) 511 ; 512 _kvm_err(kd, kd->program, 513 "%s: no such symbol", p->n_name); 514 return (0); 515 } 516 if (KREAD(kd, nl[0].n_value, &nprocs)) { 517 _kvm_err(kd, kd->program, "can't read nprocs"); 518 return (0); 519 } 520 nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value, 521 nl[2].n_value); 522 #ifdef notdef 523 size = nprocs * sizeof(struct kinfo_proc); 524 (void)realloc(kd->procbase, size); 525 #endif 526 } 527 *cnt = nprocs; 528 return (kd->procbase); 529 } 530 531 void 532 _kvm_freeprocs(kvm_t *kd) 533 { 534 if (kd->procbase) { 535 free(kd->procbase); 536 kd->procbase = 0; 537 } 538 } 539 540 void * 541 _kvm_realloc(kvm_t *kd, void *p, size_t n) 542 { 543 void *np = (void *)realloc(p, n); 544 545 if (np == 0) { 546 free(p); 547 _kvm_err(kd, kd->program, "out of memory"); 548 } 549 return (np); 550 } 551 552 #ifndef MAX 553 #define MAX(a, b) ((a) > (b) ? (a) : (b)) 554 #endif 555 556 /* 557 * Read in an argument vector from the user address space of process pid. 558 * addr if the user-space base address of narg null-terminated contiguous 559 * strings. This is used to read in both the command arguments and 560 * environment strings. Read at most maxcnt characters of strings. 561 */ 562 static char ** 563 kvm_argv(kvm_t *kd, pid_t pid, u_long addr, int narg, int maxcnt) 564 { 565 char *np, *cp, *ep, *ap; 566 u_long oaddr = -1; 567 int len, cc; 568 char **argv; 569 570 /* 571 * Check that there aren't an unreasonable number of agruments, 572 * and that the address is in user space. 573 */ 574 if (narg > 512 || 575 addr < VM_MIN_USER_ADDRESS || addr >= VM_MAX_USER_ADDRESS) { 576 return (0); 577 } 578 579 /* 580 * kd->argv : work space for fetching the strings from the target 581 * process's space, and is converted for returning to caller 582 */ 583 if (kd->argv == 0) { 584 /* 585 * Try to avoid reallocs. 586 */ 587 kd->argc = MAX(narg + 1, 32); 588 kd->argv = (char **)_kvm_malloc(kd, kd->argc * 589 sizeof(*kd->argv)); 590 if (kd->argv == 0) 591 return (0); 592 } else if (narg + 1 > kd->argc) { 593 kd->argc = MAX(2 * kd->argc, narg + 1); 594 kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * 595 sizeof(*kd->argv)); 596 if (kd->argv == 0) 597 return (0); 598 } 599 /* 600 * kd->argspc : returned to user, this is where the kd->argv 601 * arrays are left pointing to the collected strings. 602 */ 603 if (kd->argspc == 0) { 604 kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE); 605 if (kd->argspc == 0) 606 return (0); 607 kd->arglen = PAGE_SIZE; 608 } 609 /* 610 * kd->argbuf : used to pull in pages from the target process. 611 * the strings are copied out of here. 612 */ 613 if (kd->argbuf == 0) { 614 kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE); 615 if (kd->argbuf == 0) 616 return (0); 617 } 618 619 /* Pull in the target process'es argv vector */ 620 cc = sizeof(char *) * narg; 621 if (kvm_uread(kd, pid, addr, (char *)kd->argv, cc) != cc) 622 return (0); 623 /* 624 * ap : saved start address of string we're working on in kd->argspc 625 * np : pointer to next place to write in kd->argspc 626 * len: length of data in kd->argspc 627 * argv: pointer to the argv vector that we are hunting around the 628 * target process space for, and converting to addresses in 629 * our address space (kd->argspc). 630 */ 631 ap = np = kd->argspc; 632 argv = kd->argv; 633 len = 0; 634 /* 635 * Loop over pages, filling in the argument vector. 636 * Note that the argv strings could be pointing *anywhere* in 637 * the user address space and are no longer contiguous. 638 * Note that *argv is modified when we are going to fetch a string 639 * that crosses a page boundary. We copy the next part of the string 640 * into to "np" and eventually convert the pointer. 641 */ 642 while (argv < kd->argv + narg && *argv != 0) { 643 644 /* get the address that the current argv string is on */ 645 addr = (u_long)*argv & ~(PAGE_SIZE - 1); 646 647 /* is it the same page as the last one? */ 648 if (addr != oaddr) { 649 if (kvm_uread(kd, pid, addr, kd->argbuf, PAGE_SIZE) != 650 PAGE_SIZE) 651 return (0); 652 oaddr = addr; 653 } 654 655 /* offset within the page... kd->argbuf */ 656 addr = (u_long)*argv & (PAGE_SIZE - 1); 657 658 /* cp = start of string, cc = count of chars in this chunk */ 659 cp = kd->argbuf + addr; 660 cc = PAGE_SIZE - addr; 661 662 /* dont get more than asked for by user process */ 663 if (maxcnt > 0 && cc > maxcnt - len) 664 cc = maxcnt - len; 665 666 /* pointer to end of string if we found it in this page */ 667 ep = memchr(cp, '\0', cc); 668 if (ep != 0) 669 cc = ep - cp + 1; 670 /* 671 * at this point, cc is the count of the chars that we are 672 * going to retrieve this time. we may or may not have found 673 * the end of it. (ep points to the null if the end is known) 674 */ 675 676 /* will we exceed the malloc/realloced buffer? */ 677 if (len + cc > kd->arglen) { 678 int off; 679 char **pp; 680 char *op = kd->argspc; 681 682 kd->arglen *= 2; 683 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, 684 kd->arglen); 685 if (kd->argspc == 0) 686 return (0); 687 /* 688 * Adjust argv pointers in case realloc moved 689 * the string space. 690 */ 691 off = kd->argspc - op; 692 for (pp = kd->argv; pp < argv; pp++) 693 *pp += off; 694 ap += off; 695 np += off; 696 } 697 /* np = where to put the next part of the string in kd->argspc*/ 698 /* np is kinda redundant.. could use "kd->argspc + len" */ 699 memcpy(np, cp, cc); 700 np += cc; /* inc counters */ 701 len += cc; 702 703 /* 704 * if end of string found, set the *argv pointer to the 705 * saved beginning of string, and advance. argv points to 706 * somewhere in kd->argv.. This is initially relative 707 * to the target process, but when we close it off, we set 708 * it to point in our address space. 709 */ 710 if (ep != 0) { 711 *argv++ = ap; 712 ap = np; 713 } else { 714 /* update the address relative to the target process */ 715 *argv += cc; 716 } 717 718 if (maxcnt > 0 && len >= maxcnt) { 719 /* 720 * We're stopping prematurely. Terminate the 721 * current string. 722 */ 723 if (ep == 0) { 724 *np = '\0'; 725 *argv++ = ap; 726 } 727 break; 728 } 729 } 730 /* Make sure argv is terminated. */ 731 *argv = 0; 732 return (kd->argv); 733 } 734 735 static void 736 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 737 { 738 *addr = (u_long)p->ps_argvstr; 739 *n = p->ps_nargvstr; 740 } 741 742 static void 743 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 744 { 745 *addr = (u_long)p->ps_envstr; 746 *n = p->ps_nenvstr; 747 } 748 749 /* 750 * Determine if the proc indicated by p is still active. 751 * This test is not 100% foolproof in theory, but chances of 752 * being wrong are very low. 753 */ 754 static int 755 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 756 { 757 struct kinfo_proc kp; 758 int mib[4]; 759 size_t len; 760 int error; 761 762 mib[0] = CTL_KERN; 763 mib[1] = KERN_PROC; 764 mib[2] = KERN_PROC_PID; 765 mib[3] = p->kp_pid; 766 767 len = sizeof(kp); 768 error = sysctl(mib, 4, &kp, &len, NULL, 0); 769 if (error) 770 return (0); 771 772 error = (p->kp_pid == kp.kp_pid && 773 (kp.kp_stat != SZOMB || p->kp_stat == SZOMB)); 774 return (error); 775 } 776 777 static char ** 778 kvm_doargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr, 779 void (*info)(struct ps_strings *, u_long *, int *)) 780 { 781 char **ap; 782 u_long addr; 783 int cnt; 784 static struct ps_strings arginfo; 785 static u_long ps_strings; 786 size_t len; 787 788 if (ps_strings == NULL) { 789 len = sizeof(ps_strings); 790 if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL, 791 0) == -1) 792 ps_strings = PS_STRINGS; 793 } 794 795 /* 796 * Pointers are stored at the top of the user stack. 797 */ 798 if (kp->kp_stat == SZOMB || 799 kvm_uread(kd, kp->kp_pid, ps_strings, (char *)&arginfo, 800 sizeof(arginfo)) != sizeof(arginfo)) 801 return (0); 802 803 (*info)(&arginfo, &addr, &cnt); 804 if (cnt == 0) 805 return (0); 806 ap = kvm_argv(kd, kp->kp_pid, addr, cnt, nchr); 807 /* 808 * For live kernels, make sure this process didn't go away. 809 */ 810 if (ap != 0 && ISALIVE(kd) && 811 !proc_verify(kd, kp)) 812 ap = 0; 813 return (ap); 814 } 815 816 /* 817 * Get the command args. This code is now machine independent. 818 */ 819 char ** 820 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 821 { 822 int oid[4]; 823 int i; 824 size_t bufsz; 825 static unsigned long buflen; 826 static char *buf, *p; 827 static char **bufp; 828 static int argc; 829 830 if (!ISALIVE(kd)) { 831 _kvm_err(kd, kd->program, 832 "cannot read user space from dead kernel"); 833 return (0); 834 } 835 836 if (!buflen) { 837 bufsz = sizeof(buflen); 838 i = sysctlbyname("kern.ps_arg_cache_limit", 839 &buflen, &bufsz, NULL, 0); 840 if (i == -1) { 841 buflen = 0; 842 } else { 843 buf = malloc(buflen); 844 if (buf == NULL) 845 buflen = 0; 846 argc = 32; 847 bufp = malloc(sizeof(char *) * argc); 848 } 849 } 850 if (buf != NULL) { 851 oid[0] = CTL_KERN; 852 oid[1] = KERN_PROC; 853 oid[2] = KERN_PROC_ARGS; 854 oid[3] = kp->kp_pid; 855 bufsz = buflen; 856 i = sysctl(oid, 4, buf, &bufsz, 0, 0); 857 if (i == 0 && bufsz > 0) { 858 i = 0; 859 p = buf; 860 do { 861 bufp[i++] = p; 862 p += strlen(p) + 1; 863 if (i >= argc) { 864 argc += argc; 865 bufp = realloc(bufp, 866 sizeof(char *) * argc); 867 } 868 } while (p < buf + bufsz); 869 bufp[i++] = 0; 870 return (bufp); 871 } 872 } 873 if (kp->kp_flags & P_SYSTEM) 874 return (NULL); 875 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 876 } 877 878 char ** 879 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 880 { 881 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 882 } 883 884 /* 885 * Read from user space. The user context is given by pid. 886 */ 887 ssize_t 888 kvm_uread(kvm_t *kd, pid_t pid, u_long uva, char *buf, size_t len) 889 { 890 char *cp; 891 char procfile[MAXPATHLEN]; 892 ssize_t amount; 893 int fd; 894 895 if (!ISALIVE(kd)) { 896 _kvm_err(kd, kd->program, 897 "cannot read user space from dead kernel"); 898 return (0); 899 } 900 901 sprintf(procfile, "/proc/%d/mem", pid); 902 fd = open(procfile, O_RDONLY, 0); 903 if (fd < 0) { 904 _kvm_err(kd, kd->program, "cannot open %s", procfile); 905 close(fd); 906 return (0); 907 } 908 909 cp = buf; 910 while (len > 0) { 911 errno = 0; 912 if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) { 913 _kvm_err(kd, kd->program, "invalid address (%x) in %s", 914 uva, procfile); 915 break; 916 } 917 amount = read(fd, cp, len); 918 if (amount < 0) { 919 _kvm_syserr(kd, kd->program, "error reading %s", 920 procfile); 921 break; 922 } 923 if (amount == 0) { 924 _kvm_err(kd, kd->program, "EOF reading %s", procfile); 925 break; 926 } 927 cp += amount; 928 uva += amount; 929 len -= amount; 930 } 931 932 close(fd); 933 return ((ssize_t)(cp - buf)); 934 } 935