1 /* $OpenBSD: kvm_proc.c,v 1.47 2012/04/14 12:11:47 guenther 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 #include <sys/param.h> 73 #include <sys/user.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 85 #include <uvm/uvm_extern.h> 86 #include <uvm/uvm_amap.h> 87 #include <machine/vmparam.h> 88 #include <machine/pmap.h> 89 90 #include <sys/sysctl.h> 91 92 #include <limits.h> 93 #include <db.h> 94 #include <paths.h> 95 96 #include "kvm_private.h" 97 98 /* 99 * Common info from kinfo_proc used by helper routines. 100 */ 101 struct miniproc { 102 struct vmspace *p_vmspace; 103 char p_stat; 104 struct proc *p_paddr; 105 pid_t p_pid; 106 }; 107 108 /* 109 * Convert from struct kinfo_proc to miniproc. 110 */ 111 #define KPTOMINI(kp, p) \ 112 do { \ 113 (p)->p_stat = (kp)->p_stat; \ 114 (p)->p_pid = (kp)->p_pid; \ 115 (p)->p_paddr = (void *)(long)(kp)->p_paddr; \ 116 (p)->p_vmspace = (void *)(long)(kp)->p_vmspace; \ 117 } while (/*CONSTCOND*/0); 118 119 120 static char *_kvm_ureadm(kvm_t *, const struct miniproc *, u_long, u_long *); 121 static ssize_t kvm_ureadm(kvm_t *, const struct miniproc *, u_long, char *, size_t); 122 123 static char **kvm_argv(kvm_t *, const struct miniproc *, u_long, int, int); 124 125 static char **kvm_doargv(kvm_t *, const struct miniproc *, int, 126 void (*)(struct ps_strings *, u_long *, int *)); 127 static int proc_verify(kvm_t *, const struct miniproc *); 128 static void ps_str_a(struct ps_strings *, u_long *, int *); 129 static void ps_str_e(struct ps_strings *, u_long *, int *); 130 131 static char * 132 _kvm_ureadm(kvm_t *kd, const struct miniproc *p, u_long va, u_long *cnt) 133 { 134 u_long addr, offset, slot; 135 struct vmspace vm; 136 struct vm_anon *anonp, anon; 137 struct vm_map_entry vme; 138 struct vm_amap amap; 139 struct vm_page pg; 140 141 if (kd->swapspc == 0) { 142 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 143 if (kd->swapspc == 0) 144 return (NULL); 145 } 146 147 /* 148 * Look through the address map for the memory object 149 * that corresponds to the given virtual address. 150 */ 151 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 152 return (NULL); 153 addr = (u_long)RB_ROOT(&vm.vm_map.addr); 154 while (1) { 155 if (addr == 0) 156 return (NULL); 157 if (KREAD(kd, addr, &vme)) 158 return (NULL); 159 160 if (va < vme.start) 161 addr = (u_long)RB_LEFT(&vme, daddrs.addr_entry); 162 else if (va >= vme.end + vme.guard + vme.fspace) 163 addr = (u_long)RB_RIGHT(&vme, daddrs.addr_entry); 164 else if (va >= vme.end) 165 return (NULL); 166 else 167 break; 168 } 169 170 /* 171 * we found the map entry, now to find the object... 172 */ 173 if (vme.aref.ar_amap == NULL) 174 return (NULL); 175 176 addr = (u_long)vme.aref.ar_amap; 177 if (KREAD(kd, addr, &amap)) 178 return (NULL); 179 180 offset = va - vme.start; 181 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 182 /* sanity-check slot number */ 183 if (slot > amap.am_nslot) 184 return (NULL); 185 186 addr = (u_long)amap.am_anon + (offset / kd->nbpg) * sizeof(anonp); 187 if (KREAD(kd, addr, &anonp)) 188 return (NULL); 189 190 addr = (u_long)anonp; 191 if (KREAD(kd, addr, &anon)) 192 return (NULL); 193 194 addr = (u_long)anon.an_page; 195 if (addr) { 196 if (KREAD(kd, addr, &pg)) 197 return (NULL); 198 199 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 200 (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) 201 return (NULL); 202 } else { 203 if (kd->swfd == -1 || 204 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 205 (size_t)kd->nbpg, 206 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 207 return (NULL); 208 } 209 210 /* Found the page. */ 211 offset %= kd->nbpg; 212 *cnt = kd->nbpg - offset; 213 return (&kd->swapspc[offset]); 214 } 215 216 void * 217 _kvm_realloc(kvm_t *kd, void *p, size_t n) 218 { 219 void *np = (void *)realloc(p, n); 220 221 if (np == 0) 222 _kvm_err(kd, kd->program, "out of memory"); 223 return (np); 224 } 225 226 /* 227 * Read in an argument vector from the user address space of process p. 228 * addr if the user-space base address of narg null-terminated contiguous 229 * strings. This is used to read in both the command arguments and 230 * environment strings. Read at most maxcnt characters of strings. 231 */ 232 static char ** 233 kvm_argv(kvm_t *kd, const struct miniproc *p, u_long addr, int narg, 234 int maxcnt) 235 { 236 char *np, *cp, *ep, *ap, **argv; 237 u_long oaddr = -1; 238 int len, cc; 239 240 /* 241 * Check that there aren't an unreasonable number of arguments, 242 * and that the address is in user space. 243 */ 244 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 245 return (0); 246 247 if (kd->argv == 0) { 248 /* 249 * Try to avoid reallocs. 250 */ 251 kd->argc = MAX(narg + 1, 32); 252 kd->argv = _kvm_malloc(kd, kd->argc * 253 sizeof(*kd->argv)); 254 if (kd->argv == 0) 255 return (0); 256 } else if (narg + 1 > kd->argc) { 257 kd->argc = MAX(2 * kd->argc, narg + 1); 258 kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * 259 sizeof(*kd->argv)); 260 if (kd->argv == 0) 261 return (0); 262 } 263 if (kd->argspc == 0) { 264 kd->argspc = _kvm_malloc(kd, kd->nbpg); 265 if (kd->argspc == 0) 266 return (0); 267 kd->arglen = kd->nbpg; 268 } 269 if (kd->argbuf == 0) { 270 kd->argbuf = _kvm_malloc(kd, kd->nbpg); 271 if (kd->argbuf == 0) 272 return (0); 273 } 274 cc = sizeof(char *) * narg; 275 if (kvm_ureadm(kd, p, addr, (char *)kd->argv, cc) != cc) 276 return (0); 277 ap = np = kd->argspc; 278 argv = kd->argv; 279 len = 0; 280 281 /* 282 * Loop over pages, filling in the argument vector. 283 */ 284 while (argv < kd->argv + narg && *argv != 0) { 285 addr = (u_long)*argv & ~(kd->nbpg - 1); 286 if (addr != oaddr) { 287 if (kvm_ureadm(kd, p, addr, kd->argbuf, kd->nbpg) != 288 kd->nbpg) 289 return (0); 290 oaddr = addr; 291 } 292 addr = (u_long)*argv & (kd->nbpg - 1); 293 cp = kd->argbuf + addr; 294 cc = kd->nbpg - addr; 295 if (maxcnt > 0 && cc > maxcnt - len) 296 cc = maxcnt - len; 297 ep = memchr(cp, '\0', cc); 298 if (ep != 0) 299 cc = ep - cp + 1; 300 if (len + cc > kd->arglen) { 301 int off; 302 char **pp; 303 char *op = kd->argspc; 304 305 kd->arglen *= 2; 306 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, 307 kd->arglen); 308 if (kd->argspc == 0) 309 return (0); 310 /* 311 * Adjust argv pointers in case realloc moved 312 * the string space. 313 */ 314 off = kd->argspc - op; 315 for (pp = kd->argv; pp < argv; pp++) 316 *pp += off; 317 ap += off; 318 np += off; 319 } 320 memcpy(np, cp, cc); 321 np += cc; 322 len += cc; 323 if (ep != 0) { 324 *argv++ = ap; 325 ap = np; 326 } else 327 *argv += cc; 328 if (maxcnt > 0 && len >= maxcnt) { 329 /* 330 * We're stopping prematurely. Terminate the 331 * current string. 332 */ 333 if (ep == 0) { 334 *np = '\0'; 335 *argv++ = ap; 336 } 337 break; 338 } 339 } 340 /* Make sure argv is terminated. */ 341 *argv = 0; 342 return (kd->argv); 343 } 344 345 static void 346 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 347 { 348 *addr = (u_long)p->ps_argvstr; 349 *n = p->ps_nargvstr; 350 } 351 352 static void 353 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 354 { 355 *addr = (u_long)p->ps_envstr; 356 *n = p->ps_nenvstr; 357 } 358 359 /* 360 * Determine if the proc indicated by p is still active. 361 * This test is not 100% foolproof in theory, but chances of 362 * being wrong are very low. 363 */ 364 static int 365 proc_verify(kvm_t *kd, const struct miniproc *p) 366 { 367 struct proc kernproc; 368 369 /* 370 * Just read in the whole proc. It's not that big relative 371 * to the cost of the read system call. 372 */ 373 if (kvm_read(kd, (u_long)p->p_paddr, &kernproc, sizeof(kernproc)) != 374 sizeof(kernproc)) 375 return (0); 376 return (p->p_pid == kernproc.p_pid && 377 (kernproc.p_stat != SZOMB || p->p_stat == SZOMB)); 378 } 379 380 static char ** 381 kvm_doargv(kvm_t *kd, const struct miniproc *p, int nchr, 382 void (*info)(struct ps_strings *, u_long *, int *)) 383 { 384 static struct ps_strings *ps; 385 struct ps_strings arginfo; 386 u_long addr; 387 char **ap; 388 int cnt; 389 390 if (ps == NULL) { 391 struct _ps_strings _ps; 392 int mib[2]; 393 size_t len; 394 395 mib[0] = CTL_VM; 396 mib[1] = VM_PSSTRINGS; 397 len = sizeof(_ps); 398 sysctl(mib, 2, &_ps, &len, NULL, 0); 399 ps = (struct ps_strings *)_ps.val; 400 } 401 402 /* 403 * Pointers are stored at the top of the user stack. 404 */ 405 if (p->p_stat == SZOMB || 406 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 407 sizeof(arginfo)) != sizeof(arginfo)) 408 return (0); 409 410 (*info)(&arginfo, &addr, &cnt); 411 if (cnt == 0) 412 return (0); 413 ap = kvm_argv(kd, p, addr, cnt, nchr); 414 /* 415 * For live kernels, make sure this process didn't go away. 416 */ 417 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 418 ap = 0; 419 return (ap); 420 } 421 422 static char ** 423 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int env) 424 { 425 size_t len, orglen; 426 int mib[4], ret; 427 char *buf; 428 429 orglen = env ? kd->nbpg : 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 430 if (kd->argbuf == NULL && 431 (kd->argbuf = _kvm_malloc(kd, orglen)) == NULL) 432 return (NULL); 433 434 again: 435 mib[0] = CTL_KERN; 436 mib[1] = KERN_PROC_ARGS; 437 mib[2] = (int)pid; 438 mib[3] = env ? KERN_PROC_ENV : KERN_PROC_ARGV; 439 440 len = orglen; 441 ret = (sysctl(mib, 4, kd->argbuf, &len, NULL, 0) < 0); 442 if (ret && errno == ENOMEM) { 443 orglen *= 2; 444 buf = _kvm_realloc(kd, kd->argbuf, orglen); 445 if (buf == NULL) 446 return (NULL); 447 kd->argbuf = buf; 448 goto again; 449 } 450 451 if (ret) { 452 free(kd->argbuf); 453 kd->argbuf = NULL; 454 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 455 return (NULL); 456 } 457 #if 0 458 for (argv = (char **)kd->argbuf; *argv != NULL; argv++) 459 if (strlen(*argv) > nchr) 460 *argv[nchr] = '\0'; 461 #endif 462 463 return (char **)(kd->argbuf); 464 } 465 466 /* 467 * Get the command args. This code is now machine independent. 468 */ 469 char ** 470 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 471 { 472 struct miniproc p; 473 474 if (ISALIVE(kd)) 475 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 476 KPTOMINI(kp, &p); 477 return (kvm_doargv(kd, &p, nchr, ps_str_a)); 478 } 479 480 char ** 481 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 482 { 483 struct miniproc p; 484 485 if (ISALIVE(kd)) 486 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 487 KPTOMINI(kp, &p); 488 return (kvm_doargv(kd, &p, nchr, ps_str_e)); 489 } 490 491 /* 492 * Read from user space. The user context is given by p. 493 */ 494 static ssize_t 495 kvm_ureadm(kvm_t *kd, const struct miniproc *p, u_long uva, char *buf, 496 size_t len) 497 { 498 char *cp = buf; 499 500 while (len > 0) { 501 u_long cnt; 502 size_t cc; 503 char *dp; 504 505 dp = _kvm_ureadm(kd, p, uva, &cnt); 506 if (dp == 0) { 507 _kvm_err(kd, 0, "invalid address (%lx)", uva); 508 return (0); 509 } 510 cc = (size_t)MIN(cnt, len); 511 bcopy(dp, cp, cc); 512 cp += cc; 513 uva += cc; 514 len -= cc; 515 } 516 return (ssize_t)(cp - buf); 517 } 518