1 /* $OpenBSD: kvm_proc.c,v 1.61 2020/10/12 22:08:33 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> 74 #include <sys/proc.h> 75 #include <sys/exec.h> 76 #include <sys/stat.h> 77 #include <sys/ioctl.h> 78 #include <sys/tty.h> 79 #include <stddef.h> 80 #include <stdlib.h> 81 #include <string.h> 82 #include <unistd.h> 83 #include <nlist.h> 84 #include <kvm.h> 85 #include <errno.h> 86 87 #include <uvm/uvm_extern.h> 88 #include <uvm/uvm_amap.h> 89 #include <machine/vmparam.h> 90 #include <machine/pmap.h> 91 92 #include <sys/sysctl.h> 93 94 #include <limits.h> 95 #include <db.h> 96 #include <paths.h> 97 98 #include "kvm_private.h" 99 100 101 static char *_kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, u_long *); 102 static ssize_t kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, char *, size_t); 103 104 static char **kvm_argv(kvm_t *, const struct kinfo_proc *, u_long, int, int, int); 105 106 static char **kvm_doargv(kvm_t *, const struct kinfo_proc *, int, int, 107 void (*)(struct ps_strings *, u_long *, int *)); 108 static int proc_verify(kvm_t *, const struct kinfo_proc *); 109 static void ps_str_a(struct ps_strings *, u_long *, int *); 110 static void ps_str_e(struct ps_strings *, u_long *, int *); 111 112 static struct vm_anon * 113 _kvm_findanon(kvm_t *kd, struct vm_amap *amapp, int slot) 114 { 115 u_long addr; 116 int bucket; 117 struct vm_amap amap; 118 struct vm_amap_chunk chunk, *chunkp; 119 struct vm_anon *anonp; 120 121 addr = (u_long)amapp; 122 if (KREAD(kd, addr, &amap)) 123 return (NULL); 124 125 /* sanity-check slot number */ 126 if (slot > amap.am_nslot) 127 return (NULL); 128 129 if (UVM_AMAP_SMALL(&amap)) 130 chunkp = &amapp->am_small; 131 else { 132 bucket = UVM_AMAP_BUCKET(&amap, slot); 133 addr = (u_long)(amap.am_buckets + bucket); 134 if (KREAD(kd, addr, &chunkp)) 135 return (NULL); 136 137 while (chunkp != NULL) { 138 addr = (u_long)chunkp; 139 if (KREAD(kd, addr, &chunk)) 140 return (NULL); 141 142 if (UVM_AMAP_BUCKET(&amap, chunk.ac_baseslot) != 143 bucket) 144 return (NULL); 145 if (slot >= chunk.ac_baseslot && 146 slot < chunk.ac_baseslot + chunk.ac_nslot) 147 break; 148 149 chunkp = TAILQ_NEXT(&chunk, ac_list); 150 } 151 if (chunkp == NULL) 152 return (NULL); 153 } 154 155 addr = (u_long)&chunkp->ac_anon[UVM_AMAP_SLOTIDX(slot)]; 156 if (KREAD(kd, addr, &anonp)) 157 return (NULL); 158 159 return (anonp); 160 } 161 162 static char * 163 _kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long va, u_long *cnt) 164 { 165 u_long addr, offset, slot; 166 struct vmspace vm; 167 struct vm_anon *anonp, anon; 168 struct vm_map_entry vme; 169 struct vm_page pg; 170 unsigned long rboff; 171 172 if (kd->swapspc == 0) { 173 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 174 if (kd->swapspc == 0) 175 return (NULL); 176 } 177 178 rboff = (unsigned long)&vme.daddrs.addr_entry - (unsigned long)&vme; 179 180 /* 181 * Look through the address map for the memory object 182 * that corresponds to the given virtual address. 183 */ 184 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 185 return (NULL); 186 addr = (u_long)&vm.vm_map.addr.rbh_root.rbt_root; 187 while (1) { 188 if (addr == 0) 189 return (NULL); 190 addr -= rboff; 191 if (KREAD(kd, addr, &vme)) 192 return (NULL); 193 194 if (va < vme.start) 195 addr = (u_long)vme.daddrs.addr_entry.rbt_left; 196 else if (va >= vme.end + vme.guard + vme.fspace) 197 addr = (u_long)vme.daddrs.addr_entry.rbt_right; 198 else if (va >= vme.end) 199 return (NULL); 200 else 201 break; 202 } 203 204 /* 205 * we found the map entry, now to find the object... 206 */ 207 if (vme.aref.ar_amap == NULL) 208 return (NULL); 209 210 offset = va - vme.start; 211 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 212 213 anonp = _kvm_findanon(kd, vme.aref.ar_amap, slot); 214 if (anonp == NULL) 215 return (NULL); 216 217 addr = (u_long)anonp; 218 if (KREAD(kd, addr, &anon)) 219 return (NULL); 220 221 addr = (u_long)anon.an_page; 222 if (addr) { 223 if (KREAD(kd, addr, &pg)) 224 return (NULL); 225 226 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 227 (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) 228 return (NULL); 229 } else { 230 if (kd->swfd == -1 || 231 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 232 (size_t)kd->nbpg, 233 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 234 return (NULL); 235 } 236 237 /* Found the page. */ 238 offset %= kd->nbpg; 239 *cnt = kd->nbpg - offset; 240 return (&kd->swapspc[offset]); 241 } 242 243 void * 244 _kvm_reallocarray(kvm_t *kd, void *p, size_t i, size_t n) 245 { 246 void *np = reallocarray(p, i, n); 247 248 if (np == 0) 249 _kvm_err(kd, kd->program, "out of memory"); 250 return (np); 251 } 252 253 /* 254 * Read in an argument vector from the user address space of process p. 255 * addr if the user-space base address of narg null-terminated contiguous 256 * strings. This is used to read in both the command arguments and 257 * environment strings. Read at most maxcnt characters of strings. 258 */ 259 static char ** 260 kvm_argv(kvm_t *kd, const struct kinfo_proc *p, u_long addr, int narg, 261 int maxcnt, int isenv) 262 { 263 char *np, *cp, *ep, *ap, **argv, ***pargv, **pargspc, **pargbuf; 264 u_long oaddr = -1; 265 int len, cc, *parglen, *pargc; 266 size_t argc; 267 268 /* 269 * Check that there aren't an unreasonable number of arguments, 270 * and that the address is in user space. 271 */ 272 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 273 return (0); 274 275 if (isenv) { 276 pargspc = &kd->envspc; 277 pargbuf = &kd->envbuf; 278 parglen = &kd->envlen; 279 pargv = &kd->envp; 280 pargc = &kd->envc; 281 } else { 282 pargspc = &kd->argspc; 283 pargbuf = &kd->argbuf; 284 parglen = &kd->arglen; 285 pargv = &kd->argv; 286 pargc = &kd->argc; 287 } 288 289 if (*pargv == 0) 290 argc = MAX(narg + 1, 32); 291 else if (narg + 1 > *pargc) 292 argc = MAX(2 * (*pargc), narg + 1); 293 else 294 goto argv_allocated; 295 argv = _kvm_reallocarray(kd, *pargv, argc, sizeof(**pargv)); 296 if (argv == 0) 297 return (0); 298 *pargv = argv; 299 *pargc = argc; 300 301 argv_allocated: 302 if (*pargspc == 0) { 303 *pargspc = _kvm_malloc(kd, kd->nbpg); 304 if (*pargspc == 0) 305 return (0); 306 *parglen = kd->nbpg; 307 } 308 if (*pargbuf == 0) { 309 *pargbuf = _kvm_malloc(kd, kd->nbpg); 310 if (*pargbuf == 0) 311 return (0); 312 } 313 cc = sizeof(char *) * narg; 314 if (kvm_ureadm(kd, p, addr, (char *)*pargv, cc) != cc) 315 return (0); 316 ap = np = *pargspc; 317 argv = *pargv; 318 len = 0; 319 320 /* 321 * Loop over pages, filling in the argument vector. 322 */ 323 while (argv < *pargv + narg && *argv != 0) { 324 addr = (u_long)*argv & ~(kd->nbpg - 1); 325 if (addr != oaddr) { 326 if (kvm_ureadm(kd, p, addr, *pargbuf, kd->nbpg) != 327 kd->nbpg) 328 return (0); 329 oaddr = addr; 330 } 331 addr = (u_long)*argv & (kd->nbpg - 1); 332 cp = *pargbuf + addr; 333 cc = kd->nbpg - addr; 334 if (maxcnt > 0 && cc > maxcnt - len) 335 cc = maxcnt - len; 336 ep = memchr(cp, '\0', cc); 337 if (ep != 0) 338 cc = ep - cp + 1; 339 if (len + cc > *parglen) { 340 ptrdiff_t off; 341 char **pp; 342 char *op = *pargspc; 343 char *newp; 344 345 newp = _kvm_reallocarray(kd, *pargspc, 346 *parglen, 2); 347 if (newp == 0) 348 return (0); 349 *pargspc = newp; 350 *parglen *= 2; 351 /* 352 * Adjust argv pointers in case realloc moved 353 * the string space. 354 */ 355 off = *pargspc - op; 356 for (pp = *pargv; pp < argv; pp++) 357 *pp += off; 358 ap += off; 359 np += off; 360 } 361 memcpy(np, cp, cc); 362 np += cc; 363 len += cc; 364 if (ep != 0) { 365 *argv++ = ap; 366 ap = np; 367 } else 368 *argv += cc; 369 if (maxcnt > 0 && len >= maxcnt) { 370 /* 371 * We're stopping prematurely. Terminate the 372 * current string. 373 */ 374 if (ep == 0) { 375 *np = '\0'; 376 *argv++ = ap; 377 } 378 break; 379 } 380 } 381 /* Make sure argv is terminated. */ 382 *argv = 0; 383 return (*pargv); 384 } 385 386 static void 387 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 388 { 389 *addr = (u_long)p->ps_argvstr; 390 *n = p->ps_nargvstr; 391 } 392 393 static void 394 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 395 { 396 *addr = (u_long)p->ps_envstr; 397 *n = p->ps_nenvstr; 398 } 399 400 /* 401 * Determine if the proc indicated by p is still active. 402 * This test is not 100% foolproof in theory, but chances of 403 * being wrong are very low. 404 */ 405 static int 406 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 407 { 408 struct proc kernproc; 409 struct process kernprocess; 410 411 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE)) 412 return (0); 413 414 /* 415 * Just read in the whole proc. It's not that big relative 416 * to the cost of the read system call. 417 */ 418 if (KREAD(kd, (u_long)p->p_paddr, &kernproc)) 419 return (0); 420 if (KREAD(kd, (u_long)kernproc.p_p, &kernprocess)) 421 return (0); 422 if (p->p_pid != kernprocess.ps_pid) 423 return (0); 424 return ((kernprocess.ps_flags & (PS_EMBRYO | PS_ZOMBIE)) == 0); 425 } 426 427 static char ** 428 kvm_doargv(kvm_t *kd, const struct kinfo_proc *p, int nchr, int isenv, 429 void (*info)(struct ps_strings *, u_long *, int *)) 430 { 431 static struct ps_strings *ps; 432 struct ps_strings arginfo; 433 u_long addr; 434 char **ap; 435 int cnt; 436 437 if (ps == NULL) { 438 struct _ps_strings _ps; 439 const int mib[2] = { CTL_VM, VM_PSSTRINGS }; 440 size_t len; 441 442 len = sizeof(_ps); 443 sysctl(mib, 2, &_ps, &len, NULL, 0); 444 ps = (struct ps_strings *)_ps.val; 445 } 446 447 /* 448 * Pointers are stored at the top of the user stack. 449 */ 450 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE) || 451 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 452 sizeof(arginfo)) != sizeof(arginfo)) 453 return (0); 454 455 (*info)(&arginfo, &addr, &cnt); 456 if (cnt == 0) 457 return (0); 458 ap = kvm_argv(kd, p, addr, cnt, nchr, isenv); 459 /* 460 * For live kernels, make sure this process didn't go away. 461 */ 462 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 463 ap = 0; 464 return (ap); 465 } 466 467 static char ** 468 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int isenv) 469 { 470 size_t len, orglen; 471 int mib[4], ret; 472 char *buf, **pargbuf; 473 474 if (isenv) { 475 pargbuf = &kd->envbuf; 476 orglen = kd->nbpg; 477 } else { 478 pargbuf = &kd->argbuf; 479 orglen = 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 480 } 481 if (*pargbuf == NULL && 482 (*pargbuf = _kvm_malloc(kd, orglen)) == NULL) 483 return (NULL); 484 485 again: 486 mib[0] = CTL_KERN; 487 mib[1] = KERN_PROC_ARGS; 488 mib[2] = (int)pid; 489 mib[3] = isenv ? KERN_PROC_ENV : KERN_PROC_ARGV; 490 491 len = orglen; 492 ret = (sysctl(mib, 4, *pargbuf, &len, NULL, 0) == -1); 493 if (ret && errno == ENOMEM) { 494 buf = _kvm_reallocarray(kd, *pargbuf, orglen, 2); 495 if (buf == NULL) 496 return (NULL); 497 orglen *= 2; 498 *pargbuf = buf; 499 goto again; 500 } 501 502 if (ret) { 503 free(*pargbuf); 504 *pargbuf = NULL; 505 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 506 return (NULL); 507 } 508 #if 0 509 for (argv = (char **)*pargbuf; *argv != NULL; argv++) 510 if (strlen(*argv) > nchr) 511 *argv[nchr] = '\0'; 512 #endif 513 514 return (char **)(*pargbuf); 515 } 516 517 /* 518 * Get the command args. This code is now machine independent. 519 */ 520 char ** 521 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 522 { 523 if (ISALIVE(kd)) 524 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 525 return (kvm_doargv(kd, kp, nchr, 0, ps_str_a)); 526 } 527 528 char ** 529 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 530 { 531 if (ISALIVE(kd)) 532 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 533 return (kvm_doargv(kd, kp, nchr, 1, ps_str_e)); 534 } 535 536 /* 537 * Read from user space. The user context is given by p. 538 */ 539 static ssize_t 540 kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long uva, char *buf, 541 size_t len) 542 { 543 char *cp = buf; 544 545 while (len > 0) { 546 u_long cnt; 547 size_t cc; 548 char *dp; 549 550 dp = _kvm_ureadm(kd, p, uva, &cnt); 551 if (dp == 0) { 552 _kvm_err(kd, 0, "invalid address (%lx)", uva); 553 return (0); 554 } 555 cc = (size_t)MIN(cnt, len); 556 memcpy(cp, dp, cc); 557 cp += cc; 558 uva += cc; 559 len -= cc; 560 } 561 return (ssize_t)(cp - buf); 562 } 563