1 /* $OpenBSD: kvm_proc.c,v 1.52 2014/10/22 04:13:35 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 #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 char * 112 _kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long va, u_long *cnt) 113 { 114 u_long addr, offset, slot; 115 struct vmspace vm; 116 struct vm_anon *anonp, anon; 117 struct vm_map_entry vme; 118 struct vm_amap amap; 119 struct vm_page pg; 120 121 if (kd->swapspc == 0) { 122 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 123 if (kd->swapspc == 0) 124 return (NULL); 125 } 126 127 /* 128 * Look through the address map for the memory object 129 * that corresponds to the given virtual address. 130 */ 131 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 132 return (NULL); 133 addr = (u_long)RB_ROOT(&vm.vm_map.addr); 134 while (1) { 135 if (addr == 0) 136 return (NULL); 137 if (KREAD(kd, addr, &vme)) 138 return (NULL); 139 140 if (va < vme.start) 141 addr = (u_long)RB_LEFT(&vme, daddrs.addr_entry); 142 else if (va >= vme.end + vme.guard + vme.fspace) 143 addr = (u_long)RB_RIGHT(&vme, daddrs.addr_entry); 144 else if (va >= vme.end) 145 return (NULL); 146 else 147 break; 148 } 149 150 /* 151 * we found the map entry, now to find the object... 152 */ 153 if (vme.aref.ar_amap == NULL) 154 return (NULL); 155 156 addr = (u_long)vme.aref.ar_amap; 157 if (KREAD(kd, addr, &amap)) 158 return (NULL); 159 160 offset = va - vme.start; 161 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 162 /* sanity-check slot number */ 163 if (slot > amap.am_nslot) 164 return (NULL); 165 166 addr = (u_long)amap.am_anon + (offset / kd->nbpg) * sizeof(anonp); 167 if (KREAD(kd, addr, &anonp)) 168 return (NULL); 169 170 addr = (u_long)anonp; 171 if (KREAD(kd, addr, &anon)) 172 return (NULL); 173 174 addr = (u_long)anon.an_page; 175 if (addr) { 176 if (KREAD(kd, addr, &pg)) 177 return (NULL); 178 179 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 180 (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) 181 return (NULL); 182 } else { 183 if (kd->swfd == -1 || 184 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 185 (size_t)kd->nbpg, 186 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 187 return (NULL); 188 } 189 190 /* Found the page. */ 191 offset %= kd->nbpg; 192 *cnt = kd->nbpg - offset; 193 return (&kd->swapspc[offset]); 194 } 195 196 void * 197 _kvm_reallocarray(kvm_t *kd, void *p, size_t i, size_t n) 198 { 199 void *np = reallocarray(p, i, n); 200 201 if (np == 0) 202 _kvm_err(kd, kd->program, "out of memory"); 203 return (np); 204 } 205 206 /* 207 * Read in an argument vector from the user address space of process p. 208 * addr if the user-space base address of narg null-terminated contiguous 209 * strings. This is used to read in both the command arguments and 210 * environment strings. Read at most maxcnt characters of strings. 211 */ 212 static char ** 213 kvm_argv(kvm_t *kd, const struct kinfo_proc *p, u_long addr, int narg, 214 int maxcnt) 215 { 216 char *np, *cp, *ep, *ap, **argv; 217 u_long oaddr = -1; 218 int len, cc; 219 220 /* 221 * Check that there aren't an unreasonable number of arguments, 222 * and that the address is in user space. 223 */ 224 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 225 return (0); 226 227 if (kd->argv == 0) { 228 /* 229 * Try to avoid reallocs. 230 */ 231 kd->argc = MAX(narg + 1, 32); 232 kd->argv = _kvm_reallocarray(kd, NULL, kd->argc, 233 sizeof(*kd->argv)); 234 if (kd->argv == 0) 235 return (0); 236 } else if (narg + 1 > kd->argc) { 237 kd->argc = MAX(2 * kd->argc, narg + 1); 238 kd->argv = (char **)_kvm_reallocarray(kd, kd->argv, kd->argc, 239 sizeof(*kd->argv)); 240 if (kd->argv == 0) 241 return (0); 242 } 243 if (kd->argspc == 0) { 244 kd->argspc = _kvm_malloc(kd, kd->nbpg); 245 if (kd->argspc == 0) 246 return (0); 247 kd->arglen = kd->nbpg; 248 } 249 if (kd->argbuf == 0) { 250 kd->argbuf = _kvm_malloc(kd, kd->nbpg); 251 if (kd->argbuf == 0) 252 return (0); 253 } 254 cc = sizeof(char *) * narg; 255 if (kvm_ureadm(kd, p, addr, (char *)kd->argv, cc) != cc) 256 return (0); 257 ap = np = kd->argspc; 258 argv = kd->argv; 259 len = 0; 260 261 /* 262 * Loop over pages, filling in the argument vector. 263 */ 264 while (argv < kd->argv + narg && *argv != 0) { 265 addr = (u_long)*argv & ~(kd->nbpg - 1); 266 if (addr != oaddr) { 267 if (kvm_ureadm(kd, p, addr, kd->argbuf, kd->nbpg) != 268 kd->nbpg) 269 return (0); 270 oaddr = addr; 271 } 272 addr = (u_long)*argv & (kd->nbpg - 1); 273 cp = kd->argbuf + addr; 274 cc = kd->nbpg - addr; 275 if (maxcnt > 0 && cc > maxcnt - len) 276 cc = maxcnt - len; 277 ep = memchr(cp, '\0', cc); 278 if (ep != 0) 279 cc = ep - cp + 1; 280 if (len + cc > kd->arglen) { 281 int off; 282 char **pp; 283 char *op = kd->argspc; 284 char *newp; 285 286 newp = _kvm_reallocarray(kd, kd->argspc, 287 kd->arglen, 2); 288 if (newp == 0) 289 return (0); 290 kd->argspc = newp; 291 kd->arglen *= 2; 292 /* 293 * Adjust argv pointers in case realloc moved 294 * the string space. 295 */ 296 off = kd->argspc - op; 297 for (pp = kd->argv; pp < argv; pp++) 298 *pp += off; 299 ap += off; 300 np += off; 301 } 302 memcpy(np, cp, cc); 303 np += cc; 304 len += cc; 305 if (ep != 0) { 306 *argv++ = ap; 307 ap = np; 308 } else 309 *argv += cc; 310 if (maxcnt > 0 && len >= maxcnt) { 311 /* 312 * We're stopping prematurely. Terminate the 313 * current string. 314 */ 315 if (ep == 0) { 316 *np = '\0'; 317 *argv++ = ap; 318 } 319 break; 320 } 321 } 322 /* Make sure argv is terminated. */ 323 *argv = 0; 324 return (kd->argv); 325 } 326 327 static void 328 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 329 { 330 *addr = (u_long)p->ps_argvstr; 331 *n = p->ps_nargvstr; 332 } 333 334 static void 335 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 336 { 337 *addr = (u_long)p->ps_envstr; 338 *n = p->ps_nenvstr; 339 } 340 341 /* 342 * Determine if the proc indicated by p is still active. 343 * This test is not 100% foolproof in theory, but chances of 344 * being wrong are very low. 345 */ 346 static int 347 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 348 { 349 struct proc kernproc; 350 struct process kernprocess; 351 352 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE)) 353 return (0); 354 355 /* 356 * Just read in the whole proc. It's not that big relative 357 * to the cost of the read system call. 358 */ 359 if (KREAD(kd, (u_long)p->p_paddr, &kernproc)) 360 return (0); 361 if (p->p_pid != kernproc.p_pid) 362 return (0); 363 if (KREAD(kd, (u_long)kernproc.p_p, &kernprocess)) 364 return (0); 365 return ((kernprocess.ps_flags & (PS_EMBRYO | PS_ZOMBIE)) == 0); 366 } 367 368 static char ** 369 kvm_doargv(kvm_t *kd, const struct kinfo_proc *p, int nchr, 370 void (*info)(struct ps_strings *, u_long *, int *)) 371 { 372 static struct ps_strings *ps; 373 struct ps_strings arginfo; 374 u_long addr; 375 char **ap; 376 int cnt; 377 378 if (ps == NULL) { 379 struct _ps_strings _ps; 380 int mib[2]; 381 size_t len; 382 383 mib[0] = CTL_VM; 384 mib[1] = VM_PSSTRINGS; 385 len = sizeof(_ps); 386 sysctl(mib, 2, &_ps, &len, NULL, 0); 387 ps = (struct ps_strings *)_ps.val; 388 } 389 390 /* 391 * Pointers are stored at the top of the user stack. 392 */ 393 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE) || 394 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 395 sizeof(arginfo)) != sizeof(arginfo)) 396 return (0); 397 398 (*info)(&arginfo, &addr, &cnt); 399 if (cnt == 0) 400 return (0); 401 ap = kvm_argv(kd, p, addr, cnt, nchr); 402 /* 403 * For live kernels, make sure this process didn't go away. 404 */ 405 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 406 ap = 0; 407 return (ap); 408 } 409 410 static char ** 411 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int env) 412 { 413 size_t len, orglen; 414 int mib[4], ret; 415 char *buf; 416 417 orglen = env ? kd->nbpg : 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 418 if (kd->argbuf == NULL && 419 (kd->argbuf = _kvm_malloc(kd, orglen)) == NULL) 420 return (NULL); 421 422 again: 423 mib[0] = CTL_KERN; 424 mib[1] = KERN_PROC_ARGS; 425 mib[2] = (int)pid; 426 mib[3] = env ? KERN_PROC_ENV : KERN_PROC_ARGV; 427 428 len = orglen; 429 ret = (sysctl(mib, 4, kd->argbuf, &len, NULL, 0) < 0); 430 if (ret && errno == ENOMEM) { 431 buf = _kvm_reallocarray(kd, kd->argbuf, orglen, 2); 432 if (buf == NULL) 433 return (NULL); 434 orglen *= 2; 435 kd->argbuf = buf; 436 goto again; 437 } 438 439 if (ret) { 440 free(kd->argbuf); 441 kd->argbuf = NULL; 442 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 443 return (NULL); 444 } 445 #if 0 446 for (argv = (char **)kd->argbuf; *argv != NULL; argv++) 447 if (strlen(*argv) > nchr) 448 *argv[nchr] = '\0'; 449 #endif 450 451 return (char **)(kd->argbuf); 452 } 453 454 /* 455 * Get the command args. This code is now machine independent. 456 */ 457 char ** 458 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 459 { 460 if (ISALIVE(kd)) 461 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 462 return (kvm_doargv(kd, kp, nchr, ps_str_a)); 463 } 464 465 char ** 466 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 467 { 468 if (ISALIVE(kd)) 469 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 470 return (kvm_doargv(kd, kp, nchr, ps_str_e)); 471 } 472 473 /* 474 * Read from user space. The user context is given by p. 475 */ 476 static ssize_t 477 kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long uva, char *buf, 478 size_t len) 479 { 480 char *cp = buf; 481 482 while (len > 0) { 483 u_long cnt; 484 size_t cc; 485 char *dp; 486 487 dp = _kvm_ureadm(kd, p, uva, &cnt); 488 if (dp == 0) { 489 _kvm_err(kd, 0, "invalid address (%lx)", uva); 490 return (0); 491 } 492 cc = (size_t)MIN(cnt, len); 493 bcopy(dp, cp, cc); 494 cp += cc; 495 uva += cc; 496 len -= cc; 497 } 498 return (ssize_t)(cp - buf); 499 } 500