1 /* $OpenBSD: kvm_proc.c,v 1.56 2016/05/26 13:37:26 stefan 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 <stdlib.h> 80 #include <string.h> 81 #include <unistd.h> 82 #include <nlist.h> 83 #include <kvm.h> 84 #include <errno.h> 85 86 #include <uvm/uvm_extern.h> 87 #include <uvm/uvm_amap.h> 88 #include <machine/vmparam.h> 89 #include <machine/pmap.h> 90 91 #include <sys/sysctl.h> 92 93 #include <limits.h> 94 #include <db.h> 95 #include <paths.h> 96 97 #include "kvm_private.h" 98 99 100 static char *_kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, u_long *); 101 static ssize_t kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, char *, size_t); 102 103 static char **kvm_argv(kvm_t *, const struct kinfo_proc *, u_long, int, int); 104 105 static char **kvm_doargv(kvm_t *, const struct kinfo_proc *, int, 106 void (*)(struct ps_strings *, u_long *, int *)); 107 static int proc_verify(kvm_t *, const struct kinfo_proc *); 108 static void ps_str_a(struct ps_strings *, u_long *, int *); 109 static void ps_str_e(struct ps_strings *, u_long *, int *); 110 111 static struct vm_anon * 112 _kvm_findanon(kvm_t *kd, struct vm_amap *amapp, int slot) 113 { 114 u_long addr; 115 int bucket; 116 struct vm_amap amap; 117 struct vm_amap_chunk chunk, *chunkp; 118 struct vm_anon *anonp; 119 120 addr = (u_long)amapp; 121 if (KREAD(kd, addr, &amap)) 122 return (NULL); 123 124 /* sanity-check slot number */ 125 if (slot > amap.am_nslot) 126 return (NULL); 127 128 if (UVM_AMAP_SMALL(&amap)) 129 chunkp = &amapp->am_small; 130 else { 131 bucket = UVM_AMAP_BUCKET(&amap, slot); 132 addr = (u_long)(amap.am_buckets + bucket); 133 if (KREAD(kd, addr, &chunkp)) 134 return (NULL); 135 136 while (chunkp != NULL) { 137 addr = (u_long)chunkp; 138 if (KREAD(kd, addr, &chunk)) 139 return (NULL); 140 141 if (UVM_AMAP_BUCKET(&amap, chunk.ac_baseslot) != 142 bucket) 143 return (NULL); 144 if (slot >= chunk.ac_baseslot && 145 slot < chunk.ac_baseslot + chunk.ac_nslot) 146 break; 147 148 chunkp = TAILQ_NEXT(&chunk, ac_list); 149 } 150 if (chunkp == NULL) 151 return (NULL); 152 } 153 154 addr = (u_long)&chunkp->ac_anon[UVM_AMAP_SLOTIDX(slot)]; 155 if (KREAD(kd, addr, &anonp)) 156 return (NULL); 157 158 return (anonp); 159 } 160 161 static char * 162 _kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long va, u_long *cnt) 163 { 164 u_long addr, offset, slot; 165 struct vmspace vm; 166 struct vm_anon *anonp, anon; 167 struct vm_map_entry vme; 168 struct vm_page pg; 169 170 if (kd->swapspc == 0) { 171 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 172 if (kd->swapspc == 0) 173 return (NULL); 174 } 175 176 /* 177 * Look through the address map for the memory object 178 * that corresponds to the given virtual address. 179 */ 180 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 181 return (NULL); 182 addr = (u_long)RB_ROOT(&vm.vm_map.addr); 183 while (1) { 184 if (addr == 0) 185 return (NULL); 186 if (KREAD(kd, addr, &vme)) 187 return (NULL); 188 189 if (va < vme.start) 190 addr = (u_long)RB_LEFT(&vme, daddrs.addr_entry); 191 else if (va >= vme.end + vme.guard + vme.fspace) 192 addr = (u_long)RB_RIGHT(&vme, daddrs.addr_entry); 193 else if (va >= vme.end) 194 return (NULL); 195 else 196 break; 197 } 198 199 /* 200 * we found the map entry, now to find the object... 201 */ 202 if (vme.aref.ar_amap == NULL) 203 return (NULL); 204 205 offset = va - vme.start; 206 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 207 208 anonp = _kvm_findanon(kd, vme.aref.ar_amap, slot); 209 if (anonp == NULL) 210 return (NULL); 211 212 addr = (u_long)anonp; 213 if (KREAD(kd, addr, &anon)) 214 return (NULL); 215 216 addr = (u_long)anon.an_page; 217 if (addr) { 218 if (KREAD(kd, addr, &pg)) 219 return (NULL); 220 221 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 222 (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) 223 return (NULL); 224 } else { 225 if (kd->swfd == -1 || 226 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 227 (size_t)kd->nbpg, 228 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 229 return (NULL); 230 } 231 232 /* Found the page. */ 233 offset %= kd->nbpg; 234 *cnt = kd->nbpg - offset; 235 return (&kd->swapspc[offset]); 236 } 237 238 void * 239 _kvm_reallocarray(kvm_t *kd, void *p, size_t i, size_t n) 240 { 241 void *np = reallocarray(p, i, n); 242 243 if (np == 0) 244 _kvm_err(kd, kd->program, "out of memory"); 245 return (np); 246 } 247 248 /* 249 * Read in an argument vector from the user address space of process p. 250 * addr if the user-space base address of narg null-terminated contiguous 251 * strings. This is used to read in both the command arguments and 252 * environment strings. Read at most maxcnt characters of strings. 253 */ 254 static char ** 255 kvm_argv(kvm_t *kd, const struct kinfo_proc *p, u_long addr, int narg, 256 int maxcnt) 257 { 258 char *np, *cp, *ep, *ap, **argv; 259 u_long oaddr = -1; 260 int len, cc; 261 262 /* 263 * Check that there aren't an unreasonable number of arguments, 264 * and that the address is in user space. 265 */ 266 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 267 return (0); 268 269 if (kd->argv == 0) { 270 /* 271 * Try to avoid reallocs. 272 */ 273 kd->argc = MAX(narg + 1, 32); 274 kd->argv = _kvm_reallocarray(kd, NULL, kd->argc, 275 sizeof(*kd->argv)); 276 if (kd->argv == 0) 277 return (0); 278 } else if (narg + 1 > kd->argc) { 279 kd->argc = MAX(2 * kd->argc, narg + 1); 280 kd->argv = (char **)_kvm_reallocarray(kd, kd->argv, kd->argc, 281 sizeof(*kd->argv)); 282 if (kd->argv == 0) 283 return (0); 284 } 285 if (kd->argspc == 0) { 286 kd->argspc = _kvm_malloc(kd, kd->nbpg); 287 if (kd->argspc == 0) 288 return (0); 289 kd->arglen = kd->nbpg; 290 } 291 if (kd->argbuf == 0) { 292 kd->argbuf = _kvm_malloc(kd, kd->nbpg); 293 if (kd->argbuf == 0) 294 return (0); 295 } 296 cc = sizeof(char *) * narg; 297 if (kvm_ureadm(kd, p, addr, (char *)kd->argv, cc) != cc) 298 return (0); 299 ap = np = kd->argspc; 300 argv = kd->argv; 301 len = 0; 302 303 /* 304 * Loop over pages, filling in the argument vector. 305 */ 306 while (argv < kd->argv + narg && *argv != 0) { 307 addr = (u_long)*argv & ~(kd->nbpg - 1); 308 if (addr != oaddr) { 309 if (kvm_ureadm(kd, p, addr, kd->argbuf, kd->nbpg) != 310 kd->nbpg) 311 return (0); 312 oaddr = addr; 313 } 314 addr = (u_long)*argv & (kd->nbpg - 1); 315 cp = kd->argbuf + addr; 316 cc = kd->nbpg - addr; 317 if (maxcnt > 0 && cc > maxcnt - len) 318 cc = maxcnt - len; 319 ep = memchr(cp, '\0', cc); 320 if (ep != 0) 321 cc = ep - cp + 1; 322 if (len + cc > kd->arglen) { 323 int off; 324 char **pp; 325 char *op = kd->argspc; 326 char *newp; 327 328 newp = _kvm_reallocarray(kd, kd->argspc, 329 kd->arglen, 2); 330 if (newp == 0) 331 return (0); 332 kd->argspc = newp; 333 kd->arglen *= 2; 334 /* 335 * Adjust argv pointers in case realloc moved 336 * the string space. 337 */ 338 off = kd->argspc - op; 339 for (pp = kd->argv; pp < argv; pp++) 340 *pp += off; 341 ap += off; 342 np += off; 343 } 344 memcpy(np, cp, cc); 345 np += cc; 346 len += cc; 347 if (ep != 0) { 348 *argv++ = ap; 349 ap = np; 350 } else 351 *argv += cc; 352 if (maxcnt > 0 && len >= maxcnt) { 353 /* 354 * We're stopping prematurely. Terminate the 355 * current string. 356 */ 357 if (ep == 0) { 358 *np = '\0'; 359 *argv++ = ap; 360 } 361 break; 362 } 363 } 364 /* Make sure argv is terminated. */ 365 *argv = 0; 366 return (kd->argv); 367 } 368 369 static void 370 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 371 { 372 *addr = (u_long)p->ps_argvstr; 373 *n = p->ps_nargvstr; 374 } 375 376 static void 377 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 378 { 379 *addr = (u_long)p->ps_envstr; 380 *n = p->ps_nenvstr; 381 } 382 383 /* 384 * Determine if the proc indicated by p is still active. 385 * This test is not 100% foolproof in theory, but chances of 386 * being wrong are very low. 387 */ 388 static int 389 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 390 { 391 struct proc kernproc; 392 struct process kernprocess; 393 394 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE)) 395 return (0); 396 397 /* 398 * Just read in the whole proc. It's not that big relative 399 * to the cost of the read system call. 400 */ 401 if (KREAD(kd, (u_long)p->p_paddr, &kernproc)) 402 return (0); 403 if (p->p_pid != kernproc.p_pid) 404 return (0); 405 if (KREAD(kd, (u_long)kernproc.p_p, &kernprocess)) 406 return (0); 407 return ((kernprocess.ps_flags & (PS_EMBRYO | PS_ZOMBIE)) == 0); 408 } 409 410 static char ** 411 kvm_doargv(kvm_t *kd, const struct kinfo_proc *p, int nchr, 412 void (*info)(struct ps_strings *, u_long *, int *)) 413 { 414 static struct ps_strings *ps; 415 struct ps_strings arginfo; 416 u_long addr; 417 char **ap; 418 int cnt; 419 420 if (ps == NULL) { 421 struct _ps_strings _ps; 422 int mib[2]; 423 size_t len; 424 425 mib[0] = CTL_VM; 426 mib[1] = VM_PSSTRINGS; 427 len = sizeof(_ps); 428 sysctl(mib, 2, &_ps, &len, NULL, 0); 429 ps = (struct ps_strings *)_ps.val; 430 } 431 432 /* 433 * Pointers are stored at the top of the user stack. 434 */ 435 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE) || 436 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 437 sizeof(arginfo)) != sizeof(arginfo)) 438 return (0); 439 440 (*info)(&arginfo, &addr, &cnt); 441 if (cnt == 0) 442 return (0); 443 ap = kvm_argv(kd, p, addr, cnt, nchr); 444 /* 445 * For live kernels, make sure this process didn't go away. 446 */ 447 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 448 ap = 0; 449 return (ap); 450 } 451 452 static char ** 453 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int env) 454 { 455 size_t len, orglen; 456 int mib[4], ret; 457 char *buf; 458 459 orglen = env ? kd->nbpg : 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 460 if (kd->argbuf == NULL && 461 (kd->argbuf = _kvm_malloc(kd, orglen)) == NULL) 462 return (NULL); 463 464 again: 465 mib[0] = CTL_KERN; 466 mib[1] = KERN_PROC_ARGS; 467 mib[2] = (int)pid; 468 mib[3] = env ? KERN_PROC_ENV : KERN_PROC_ARGV; 469 470 len = orglen; 471 ret = (sysctl(mib, 4, kd->argbuf, &len, NULL, 0) < 0); 472 if (ret && errno == ENOMEM) { 473 buf = _kvm_reallocarray(kd, kd->argbuf, orglen, 2); 474 if (buf == NULL) 475 return (NULL); 476 orglen *= 2; 477 kd->argbuf = buf; 478 goto again; 479 } 480 481 if (ret) { 482 free(kd->argbuf); 483 kd->argbuf = NULL; 484 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 485 return (NULL); 486 } 487 #if 0 488 for (argv = (char **)kd->argbuf; *argv != NULL; argv++) 489 if (strlen(*argv) > nchr) 490 *argv[nchr] = '\0'; 491 #endif 492 493 return (char **)(kd->argbuf); 494 } 495 496 /* 497 * Get the command args. This code is now machine independent. 498 */ 499 char ** 500 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 501 { 502 if (ISALIVE(kd)) 503 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 504 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 505 } 506 507 char ** 508 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 509 { 510 if (ISALIVE(kd)) 511 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 512 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 513 } 514 515 /* 516 * Read from user space. The user context is given by p. 517 */ 518 static ssize_t 519 kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long uva, char *buf, 520 size_t len) 521 { 522 char *cp = buf; 523 524 while (len > 0) { 525 u_long cnt; 526 size_t cc; 527 char *dp; 528 529 dp = _kvm_ureadm(kd, p, uva, &cnt); 530 if (dp == 0) { 531 _kvm_err(kd, 0, "invalid address (%lx)", uva); 532 return (0); 533 } 534 cc = (size_t)MIN(cnt, len); 535 memcpy(cp, dp, cc); 536 cp += cc; 537 uva += cc; 538 len -= cc; 539 } 540 return (ssize_t)(cp - buf); 541 } 542