1 /* $OpenBSD: kvm_proc.c,v 1.63 2022/02/22 17:35:01 deraadt Exp $ */ 2 /* $NetBSD: kvm_proc.c,v 1.30 1999/03/24 05:50:50 mrg Exp $ */ 3 /*- 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 /*- 32 * Copyright (c) 1994, 1995 Charles M. Hannum. All rights reserved. 33 * Copyright (c) 1989, 1992, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * This code is derived from software developed by the Computer Systems 37 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract 38 * BG 91-66 and contributed to Berkeley. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of the University nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 */ 64 65 /* 66 * Proc traversal interface for kvm. ps and w are (probably) the exclusive 67 * users of this code, so we've factored it out into a separate module. 68 * Thus, we keep this grunge out of the other kvm applications (i.e., 69 * most other applications are interested only in open/close/read/nlist). 70 */ 71 72 #define __need_process 73 #include <sys/param.h> /* VM_MIN_ADDRESS PAGE_SIZE */ 74 #include <sys/types.h> 75 #include <sys/signal.h> 76 #include <sys/proc.h> 77 #include <sys/exec.h> 78 #include <sys/stat.h> 79 #include <sys/ioctl.h> 80 #include <sys/tty.h> 81 #include <stddef.h> 82 #include <stdlib.h> 83 #include <string.h> 84 #include <unistd.h> 85 #include <nlist.h> 86 #include <kvm.h> 87 #include <errno.h> 88 89 #include <uvm/uvm_extern.h> 90 #include <uvm/uvm_amap.h> 91 #include <machine/vmparam.h> 92 #include <machine/pmap.h> 93 94 #include <sys/sysctl.h> 95 96 #include <limits.h> 97 #include <db.h> 98 #include <paths.h> 99 100 #include "kvm_private.h" 101 102 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) 103 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 104 105 static char *_kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, u_long *); 106 static ssize_t kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, char *, size_t); 107 108 static char **kvm_argv(kvm_t *, const struct kinfo_proc *, u_long, int, int, int); 109 110 static char **kvm_doargv(kvm_t *, const struct kinfo_proc *, int, int, 111 void (*)(struct ps_strings *, u_long *, int *)); 112 static int proc_verify(kvm_t *, const struct kinfo_proc *); 113 static void ps_str_a(struct ps_strings *, u_long *, int *); 114 static void ps_str_e(struct ps_strings *, u_long *, int *); 115 116 static struct vm_anon * 117 _kvm_findanon(kvm_t *kd, struct vm_amap *amapp, int slot) 118 { 119 u_long addr; 120 int bucket; 121 struct vm_amap amap; 122 struct vm_amap_chunk chunk, *chunkp; 123 struct vm_anon *anonp; 124 125 addr = (u_long)amapp; 126 if (KREAD(kd, addr, &amap)) 127 return (NULL); 128 129 /* sanity-check slot number */ 130 if (slot > amap.am_nslot) 131 return (NULL); 132 133 if (UVM_AMAP_SMALL(&amap)) 134 chunkp = &amapp->am_small; 135 else { 136 bucket = UVM_AMAP_BUCKET(&amap, slot); 137 addr = (u_long)(amap.am_buckets + bucket); 138 if (KREAD(kd, addr, &chunkp)) 139 return (NULL); 140 141 while (chunkp != NULL) { 142 addr = (u_long)chunkp; 143 if (KREAD(kd, addr, &chunk)) 144 return (NULL); 145 146 if (UVM_AMAP_BUCKET(&amap, chunk.ac_baseslot) != 147 bucket) 148 return (NULL); 149 if (slot >= chunk.ac_baseslot && 150 slot < chunk.ac_baseslot + chunk.ac_nslot) 151 break; 152 153 chunkp = TAILQ_NEXT(&chunk, ac_list); 154 } 155 if (chunkp == NULL) 156 return (NULL); 157 } 158 159 addr = (u_long)&chunkp->ac_anon[UVM_AMAP_SLOTIDX(slot)]; 160 if (KREAD(kd, addr, &anonp)) 161 return (NULL); 162 163 return (anonp); 164 } 165 166 static char * 167 _kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long va, u_long *cnt) 168 { 169 u_long addr, offset, slot; 170 struct vmspace vm; 171 struct vm_anon *anonp, anon; 172 struct vm_map_entry vme; 173 struct vm_page pg; 174 unsigned long rboff; 175 176 if (kd->swapspc == 0) { 177 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 178 if (kd->swapspc == 0) 179 return (NULL); 180 } 181 182 rboff = (unsigned long)&vme.daddrs.addr_entry - (unsigned long)&vme; 183 184 /* 185 * Look through the address map for the memory object 186 * that corresponds to the given virtual address. 187 */ 188 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 189 return (NULL); 190 addr = (u_long)&vm.vm_map.addr.rbh_root.rbt_root; 191 while (1) { 192 if (addr == 0) 193 return (NULL); 194 addr -= rboff; 195 if (KREAD(kd, addr, &vme)) 196 return (NULL); 197 198 if (va < vme.start) 199 addr = (u_long)vme.daddrs.addr_entry.rbt_left; 200 else if (va >= vme.end + vme.guard + vme.fspace) 201 addr = (u_long)vme.daddrs.addr_entry.rbt_right; 202 else if (va >= vme.end) 203 return (NULL); 204 else 205 break; 206 } 207 208 /* 209 * we found the map entry, now to find the object... 210 */ 211 if (vme.aref.ar_amap == NULL) 212 return (NULL); 213 214 offset = va - vme.start; 215 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 216 217 anonp = _kvm_findanon(kd, vme.aref.ar_amap, slot); 218 if (anonp == NULL) 219 return (NULL); 220 221 addr = (u_long)anonp; 222 if (KREAD(kd, addr, &anon)) 223 return (NULL); 224 225 addr = (u_long)anon.an_page; 226 if (addr) { 227 if (KREAD(kd, addr, &pg)) 228 return (NULL); 229 230 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 231 (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) 232 return (NULL); 233 } else { 234 if (kd->swfd == -1 || 235 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 236 (size_t)kd->nbpg, 237 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 238 return (NULL); 239 } 240 241 /* Found the page. */ 242 offset %= kd->nbpg; 243 *cnt = kd->nbpg - offset; 244 return (&kd->swapspc[offset]); 245 } 246 247 void * 248 _kvm_reallocarray(kvm_t *kd, void *p, size_t i, size_t n) 249 { 250 void *np = reallocarray(p, i, n); 251 252 if (np == 0) 253 _kvm_err(kd, kd->program, "out of memory"); 254 return (np); 255 } 256 257 /* 258 * Read in an argument vector from the user address space of process p. 259 * addr if the user-space base address of narg null-terminated contiguous 260 * strings. This is used to read in both the command arguments and 261 * environment strings. Read at most maxcnt characters of strings. 262 */ 263 static char ** 264 kvm_argv(kvm_t *kd, const struct kinfo_proc *p, u_long addr, int narg, 265 int maxcnt, int isenv) 266 { 267 char *np, *cp, *ep, *ap, **argv, ***pargv, **pargspc, **pargbuf; 268 u_long oaddr = -1; 269 int len, cc, *parglen, *pargc; 270 size_t argc; 271 272 /* 273 * Check that there aren't an unreasonable number of arguments, 274 * and that the address is in user space. 275 */ 276 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 277 return (0); 278 279 if (isenv) { 280 pargspc = &kd->envspc; 281 pargbuf = &kd->envbuf; 282 parglen = &kd->envlen; 283 pargv = &kd->envp; 284 pargc = &kd->envc; 285 } else { 286 pargspc = &kd->argspc; 287 pargbuf = &kd->argbuf; 288 parglen = &kd->arglen; 289 pargv = &kd->argv; 290 pargc = &kd->argc; 291 } 292 293 if (*pargv == 0) 294 argc = MAXIMUM(narg + 1, 32); 295 else if (narg + 1 > *pargc) 296 argc = MAXIMUM(2 * (*pargc), narg + 1); 297 else 298 goto argv_allocated; 299 argv = _kvm_reallocarray(kd, *pargv, argc, sizeof(**pargv)); 300 if (argv == 0) 301 return (0); 302 *pargv = argv; 303 *pargc = argc; 304 305 argv_allocated: 306 if (*pargspc == 0) { 307 *pargspc = _kvm_malloc(kd, kd->nbpg); 308 if (*pargspc == 0) 309 return (0); 310 *parglen = kd->nbpg; 311 } 312 if (*pargbuf == 0) { 313 *pargbuf = _kvm_malloc(kd, kd->nbpg); 314 if (*pargbuf == 0) 315 return (0); 316 } 317 cc = sizeof(char *) * narg; 318 if (kvm_ureadm(kd, p, addr, (char *)*pargv, cc) != cc) 319 return (0); 320 ap = np = *pargspc; 321 argv = *pargv; 322 len = 0; 323 324 /* 325 * Loop over pages, filling in the argument vector. 326 */ 327 while (argv < *pargv + narg && *argv != 0) { 328 addr = (u_long)*argv & ~(kd->nbpg - 1); 329 if (addr != oaddr) { 330 if (kvm_ureadm(kd, p, addr, *pargbuf, kd->nbpg) != 331 kd->nbpg) 332 return (0); 333 oaddr = addr; 334 } 335 addr = (u_long)*argv & (kd->nbpg - 1); 336 cp = *pargbuf + addr; 337 cc = kd->nbpg - addr; 338 if (maxcnt > 0 && cc > maxcnt - len) 339 cc = maxcnt - len; 340 ep = memchr(cp, '\0', cc); 341 if (ep != 0) 342 cc = ep - cp + 1; 343 if (len + cc > *parglen) { 344 ptrdiff_t off; 345 char **pp; 346 char *op = *pargspc; 347 char *newp; 348 349 newp = _kvm_reallocarray(kd, *pargspc, 350 *parglen, 2); 351 if (newp == 0) 352 return (0); 353 *pargspc = newp; 354 *parglen *= 2; 355 /* 356 * Adjust argv pointers in case realloc moved 357 * the string space. 358 */ 359 off = *pargspc - op; 360 for (pp = *pargv; pp < argv; pp++) 361 *pp += off; 362 ap += off; 363 np += off; 364 } 365 memcpy(np, cp, cc); 366 np += cc; 367 len += cc; 368 if (ep != 0) { 369 *argv++ = ap; 370 ap = np; 371 } else 372 *argv += cc; 373 if (maxcnt > 0 && len >= maxcnt) { 374 /* 375 * We're stopping prematurely. Terminate the 376 * current string. 377 */ 378 if (ep == 0) { 379 *np = '\0'; 380 *argv++ = ap; 381 } 382 break; 383 } 384 } 385 /* Make sure argv is terminated. */ 386 *argv = 0; 387 return (*pargv); 388 } 389 390 static void 391 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 392 { 393 *addr = (u_long)p->ps_argvstr; 394 *n = p->ps_nargvstr; 395 } 396 397 static void 398 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 399 { 400 *addr = (u_long)p->ps_envstr; 401 *n = p->ps_nenvstr; 402 } 403 404 /* 405 * Determine if the proc indicated by p is still active. 406 * This test is not 100% foolproof in theory, but chances of 407 * being wrong are very low. 408 */ 409 static int 410 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 411 { 412 struct proc kernproc; 413 struct process kernprocess; 414 415 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE)) 416 return (0); 417 418 /* 419 * Just read in the whole proc. It's not that big relative 420 * to the cost of the read system call. 421 */ 422 if (KREAD(kd, (u_long)p->p_paddr, &kernproc)) 423 return (0); 424 if (KREAD(kd, (u_long)kernproc.p_p, &kernprocess)) 425 return (0); 426 if (p->p_pid != kernprocess.ps_pid) 427 return (0); 428 return ((kernprocess.ps_flags & (PS_EMBRYO | PS_ZOMBIE)) == 0); 429 } 430 431 static char ** 432 kvm_doargv(kvm_t *kd, const struct kinfo_proc *p, int nchr, int isenv, 433 void (*info)(struct ps_strings *, u_long *, int *)) 434 { 435 static struct ps_strings *ps; 436 struct ps_strings arginfo; 437 u_long addr; 438 char **ap; 439 int cnt; 440 441 if (ps == NULL) { 442 struct _ps_strings _ps; 443 const int mib[2] = { CTL_VM, VM_PSSTRINGS }; 444 size_t len; 445 446 len = sizeof(_ps); 447 sysctl(mib, 2, &_ps, &len, NULL, 0); 448 ps = (struct ps_strings *)_ps.val; 449 } 450 451 /* 452 * Pointers are stored at the top of the user stack. 453 */ 454 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE) || 455 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 456 sizeof(arginfo)) != sizeof(arginfo)) 457 return (0); 458 459 (*info)(&arginfo, &addr, &cnt); 460 if (cnt == 0) 461 return (0); 462 ap = kvm_argv(kd, p, addr, cnt, nchr, isenv); 463 /* 464 * For live kernels, make sure this process didn't go away. 465 */ 466 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 467 ap = 0; 468 return (ap); 469 } 470 471 static char ** 472 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int isenv) 473 { 474 size_t len, orglen; 475 int mib[4], ret; 476 char *buf, **pargbuf; 477 478 if (isenv) { 479 pargbuf = &kd->envbuf; 480 orglen = kd->nbpg; 481 } else { 482 pargbuf = &kd->argbuf; 483 orglen = 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 484 } 485 if (*pargbuf == NULL && 486 (*pargbuf = _kvm_malloc(kd, orglen)) == NULL) 487 return (NULL); 488 489 again: 490 mib[0] = CTL_KERN; 491 mib[1] = KERN_PROC_ARGS; 492 mib[2] = (int)pid; 493 mib[3] = isenv ? KERN_PROC_ENV : KERN_PROC_ARGV; 494 495 len = orglen; 496 ret = (sysctl(mib, 4, *pargbuf, &len, NULL, 0) == -1); 497 if (ret && errno == ENOMEM) { 498 buf = _kvm_reallocarray(kd, *pargbuf, orglen, 2); 499 if (buf == NULL) 500 return (NULL); 501 orglen *= 2; 502 *pargbuf = buf; 503 goto again; 504 } 505 506 if (ret) { 507 free(*pargbuf); 508 *pargbuf = NULL; 509 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 510 return (NULL); 511 } 512 #if 0 513 for (argv = (char **)*pargbuf; *argv != NULL; argv++) 514 if (strlen(*argv) > nchr) 515 *argv[nchr] = '\0'; 516 #endif 517 518 return (char **)(*pargbuf); 519 } 520 521 /* 522 * Get the command args. This code is now machine independent. 523 */ 524 char ** 525 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 526 { 527 if (ISALIVE(kd)) 528 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 529 return (kvm_doargv(kd, kp, nchr, 0, ps_str_a)); 530 } 531 532 char ** 533 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 534 { 535 if (ISALIVE(kd)) 536 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 537 return (kvm_doargv(kd, kp, nchr, 1, ps_str_e)); 538 } 539 540 /* 541 * Read from user space. The user context is given by p. 542 */ 543 static ssize_t 544 kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long uva, char *buf, 545 size_t len) 546 { 547 char *cp = buf; 548 549 while (len > 0) { 550 u_long cnt; 551 size_t cc; 552 char *dp; 553 554 dp = _kvm_ureadm(kd, p, uva, &cnt); 555 if (dp == 0) { 556 _kvm_err(kd, 0, "invalid address (%lx)", uva); 557 return (0); 558 } 559 cc = (size_t)MINIMUM(cnt, len); 560 memcpy(cp, dp, cc); 561 cp += cc; 562 uva += cc; 563 len -= cc; 564 } 565 return (ssize_t)(cp - buf); 566 } 567