1 /* $OpenBSD: kvm_proc.c,v 1.48 2013/01/14 06:32:37 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 static char *_kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, u_long *); 100 static ssize_t kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, char *, size_t); 101 102 static char **kvm_argv(kvm_t *, const struct kinfo_proc *, u_long, int, int); 103 104 static char **kvm_doargv(kvm_t *, const struct kinfo_proc *, int, 105 void (*)(struct ps_strings *, u_long *, int *)); 106 static int proc_verify(kvm_t *, const struct kinfo_proc *); 107 static void ps_str_a(struct ps_strings *, u_long *, int *); 108 static void ps_str_e(struct ps_strings *, u_long *, int *); 109 110 static char * 111 _kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long va, u_long *cnt) 112 { 113 u_long addr, offset, slot; 114 struct vmspace vm; 115 struct vm_anon *anonp, anon; 116 struct vm_map_entry vme; 117 struct vm_amap amap; 118 struct vm_page pg; 119 120 if (kd->swapspc == 0) { 121 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 122 if (kd->swapspc == 0) 123 return (NULL); 124 } 125 126 /* 127 * Look through the address map for the memory object 128 * that corresponds to the given virtual address. 129 */ 130 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 131 return (NULL); 132 addr = (u_long)RB_ROOT(&vm.vm_map.addr); 133 while (1) { 134 if (addr == 0) 135 return (NULL); 136 if (KREAD(kd, addr, &vme)) 137 return (NULL); 138 139 if (va < vme.start) 140 addr = (u_long)RB_LEFT(&vme, daddrs.addr_entry); 141 else if (va >= vme.end + vme.guard + vme.fspace) 142 addr = (u_long)RB_RIGHT(&vme, daddrs.addr_entry); 143 else if (va >= vme.end) 144 return (NULL); 145 else 146 break; 147 } 148 149 /* 150 * we found the map entry, now to find the object... 151 */ 152 if (vme.aref.ar_amap == NULL) 153 return (NULL); 154 155 addr = (u_long)vme.aref.ar_amap; 156 if (KREAD(kd, addr, &amap)) 157 return (NULL); 158 159 offset = va - vme.start; 160 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 161 /* sanity-check slot number */ 162 if (slot > amap.am_nslot) 163 return (NULL); 164 165 addr = (u_long)amap.am_anon + (offset / kd->nbpg) * sizeof(anonp); 166 if (KREAD(kd, addr, &anonp)) 167 return (NULL); 168 169 addr = (u_long)anonp; 170 if (KREAD(kd, addr, &anon)) 171 return (NULL); 172 173 addr = (u_long)anon.an_page; 174 if (addr) { 175 if (KREAD(kd, addr, &pg)) 176 return (NULL); 177 178 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 179 (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) 180 return (NULL); 181 } else { 182 if (kd->swfd == -1 || 183 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 184 (size_t)kd->nbpg, 185 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 186 return (NULL); 187 } 188 189 /* Found the page. */ 190 offset %= kd->nbpg; 191 *cnt = kd->nbpg - offset; 192 return (&kd->swapspc[offset]); 193 } 194 195 void * 196 _kvm_realloc(kvm_t *kd, void *p, size_t n) 197 { 198 void *np = (void *)realloc(p, n); 199 200 if (np == 0) 201 _kvm_err(kd, kd->program, "out of memory"); 202 return (np); 203 } 204 205 /* 206 * Read in an argument vector from the user address space of process p. 207 * addr if the user-space base address of narg null-terminated contiguous 208 * strings. This is used to read in both the command arguments and 209 * environment strings. Read at most maxcnt characters of strings. 210 */ 211 static char ** 212 kvm_argv(kvm_t *kd, const struct kinfo_proc *p, u_long addr, int narg, 213 int maxcnt) 214 { 215 char *np, *cp, *ep, *ap, **argv; 216 u_long oaddr = -1; 217 int len, cc; 218 219 /* 220 * Check that there aren't an unreasonable number of arguments, 221 * and that the address is in user space. 222 */ 223 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 224 return (0); 225 226 if (kd->argv == 0) { 227 /* 228 * Try to avoid reallocs. 229 */ 230 kd->argc = MAX(narg + 1, 32); 231 kd->argv = _kvm_malloc(kd, kd->argc * 232 sizeof(*kd->argv)); 233 if (kd->argv == 0) 234 return (0); 235 } else if (narg + 1 > kd->argc) { 236 kd->argc = MAX(2 * kd->argc, narg + 1); 237 kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * 238 sizeof(*kd->argv)); 239 if (kd->argv == 0) 240 return (0); 241 } 242 if (kd->argspc == 0) { 243 kd->argspc = _kvm_malloc(kd, kd->nbpg); 244 if (kd->argspc == 0) 245 return (0); 246 kd->arglen = kd->nbpg; 247 } 248 if (kd->argbuf == 0) { 249 kd->argbuf = _kvm_malloc(kd, kd->nbpg); 250 if (kd->argbuf == 0) 251 return (0); 252 } 253 cc = sizeof(char *) * narg; 254 if (kvm_ureadm(kd, p, addr, (char *)kd->argv, cc) != cc) 255 return (0); 256 ap = np = kd->argspc; 257 argv = kd->argv; 258 len = 0; 259 260 /* 261 * Loop over pages, filling in the argument vector. 262 */ 263 while (argv < kd->argv + narg && *argv != 0) { 264 addr = (u_long)*argv & ~(kd->nbpg - 1); 265 if (addr != oaddr) { 266 if (kvm_ureadm(kd, p, addr, kd->argbuf, kd->nbpg) != 267 kd->nbpg) 268 return (0); 269 oaddr = addr; 270 } 271 addr = (u_long)*argv & (kd->nbpg - 1); 272 cp = kd->argbuf + addr; 273 cc = kd->nbpg - addr; 274 if (maxcnt > 0 && cc > maxcnt - len) 275 cc = maxcnt - len; 276 ep = memchr(cp, '\0', cc); 277 if (ep != 0) 278 cc = ep - cp + 1; 279 if (len + cc > kd->arglen) { 280 int off; 281 char **pp; 282 char *op = kd->argspc; 283 284 kd->arglen *= 2; 285 kd->argspc = (char *)_kvm_realloc(kd, kd->argspc, 286 kd->arglen); 287 if (kd->argspc == 0) 288 return (0); 289 /* 290 * Adjust argv pointers in case realloc moved 291 * the string space. 292 */ 293 off = kd->argspc - op; 294 for (pp = kd->argv; pp < argv; pp++) 295 *pp += off; 296 ap += off; 297 np += off; 298 } 299 memcpy(np, cp, cc); 300 np += cc; 301 len += cc; 302 if (ep != 0) { 303 *argv++ = ap; 304 ap = np; 305 } else 306 *argv += cc; 307 if (maxcnt > 0 && len >= maxcnt) { 308 /* 309 * We're stopping prematurely. Terminate the 310 * current string. 311 */ 312 if (ep == 0) { 313 *np = '\0'; 314 *argv++ = ap; 315 } 316 break; 317 } 318 } 319 /* Make sure argv is terminated. */ 320 *argv = 0; 321 return (kd->argv); 322 } 323 324 static void 325 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 326 { 327 *addr = (u_long)p->ps_argvstr; 328 *n = p->ps_nargvstr; 329 } 330 331 static void 332 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 333 { 334 *addr = (u_long)p->ps_envstr; 335 *n = p->ps_nenvstr; 336 } 337 338 /* 339 * Determine if the proc indicated by p is still active. 340 * This test is not 100% foolproof in theory, but chances of 341 * being wrong are very low. 342 */ 343 static int 344 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 345 { 346 struct proc kernproc; 347 348 /* 349 * Just read in the whole proc. It's not that big relative 350 * to the cost of the read system call. 351 */ 352 if (kvm_read(kd, (u_long)p->p_paddr, &kernproc, sizeof(kernproc)) != 353 sizeof(kernproc)) 354 return (0); 355 return (p->p_pid == kernproc.p_pid && 356 (kernproc.p_stat != SZOMB || p->p_stat == SZOMB)); 357 } 358 359 static char ** 360 kvm_doargv(kvm_t *kd, const struct kinfo_proc *p, int nchr, 361 void (*info)(struct ps_strings *, u_long *, int *)) 362 { 363 static struct ps_strings *ps; 364 struct ps_strings arginfo; 365 u_long addr; 366 char **ap; 367 int cnt; 368 369 if (ps == NULL) { 370 struct _ps_strings _ps; 371 int mib[2]; 372 size_t len; 373 374 mib[0] = CTL_VM; 375 mib[1] = VM_PSSTRINGS; 376 len = sizeof(_ps); 377 sysctl(mib, 2, &_ps, &len, NULL, 0); 378 ps = (struct ps_strings *)_ps.val; 379 } 380 381 /* 382 * Pointers are stored at the top of the user stack. 383 */ 384 if (p->p_stat == SZOMB || 385 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 386 sizeof(arginfo)) != sizeof(arginfo)) 387 return (0); 388 389 (*info)(&arginfo, &addr, &cnt); 390 if (cnt == 0) 391 return (0); 392 ap = kvm_argv(kd, p, addr, cnt, nchr); 393 /* 394 * For live kernels, make sure this process didn't go away. 395 */ 396 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 397 ap = 0; 398 return (ap); 399 } 400 401 static char ** 402 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int env) 403 { 404 size_t len, orglen; 405 int mib[4], ret; 406 char *buf; 407 408 orglen = env ? kd->nbpg : 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 409 if (kd->argbuf == NULL && 410 (kd->argbuf = _kvm_malloc(kd, orglen)) == NULL) 411 return (NULL); 412 413 again: 414 mib[0] = CTL_KERN; 415 mib[1] = KERN_PROC_ARGS; 416 mib[2] = (int)pid; 417 mib[3] = env ? KERN_PROC_ENV : KERN_PROC_ARGV; 418 419 len = orglen; 420 ret = (sysctl(mib, 4, kd->argbuf, &len, NULL, 0) < 0); 421 if (ret && errno == ENOMEM) { 422 orglen *= 2; 423 buf = _kvm_realloc(kd, kd->argbuf, orglen); 424 if (buf == NULL) 425 return (NULL); 426 kd->argbuf = buf; 427 goto again; 428 } 429 430 if (ret) { 431 free(kd->argbuf); 432 kd->argbuf = NULL; 433 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 434 return (NULL); 435 } 436 #if 0 437 for (argv = (char **)kd->argbuf; *argv != NULL; argv++) 438 if (strlen(*argv) > nchr) 439 *argv[nchr] = '\0'; 440 #endif 441 442 return (char **)(kd->argbuf); 443 } 444 445 /* 446 * Get the command args. This code is now machine independent. 447 */ 448 char ** 449 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 450 { 451 if (ISALIVE(kd)) 452 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 453 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 454 } 455 456 char ** 457 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 458 { 459 if (ISALIVE(kd)) 460 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 461 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 462 } 463 464 /* 465 * Read from user space. The user context is given by p. 466 */ 467 static ssize_t 468 kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long uva, char *buf, 469 size_t len) 470 { 471 char *cp = buf; 472 473 while (len > 0) { 474 u_long cnt; 475 size_t cc; 476 char *dp; 477 478 dp = _kvm_ureadm(kd, p, uva, &cnt); 479 if (dp == 0) { 480 _kvm_err(kd, 0, "invalid address (%lx)", uva); 481 return (0); 482 } 483 cc = (size_t)MIN(cnt, len); 484 bcopy(dp, cp, cc); 485 cp += cc; 486 uva += cc; 487 len -= cc; 488 } 489 return (ssize_t)(cp - buf); 490 } 491