1 /* $OpenBSD: kvm_proc.c,v 1.64 2024/05/10 06:46:14 asou 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> /* VM_MIN_ADDRESS PAGE_SIZE */ 74 #include <sys/types.h> 75 #include <sys/signal.h> 76 #include <sys/proc.h> 77 #include <sys/exec.h> 78 #include <sys/stat.h> 79 #include <sys/ioctl.h> 80 #include <sys/tty.h> 81 #include <stddef.h> 82 #include <stdlib.h> 83 #include <string.h> 84 #include <unistd.h> 85 #include <nlist.h> 86 #include <kvm.h> 87 #include <errno.h> 88 89 #include <uvm/uvm_extern.h> 90 #include <uvm/uvm_amap.h> 91 #include <machine/vmparam.h> 92 #include <machine/pmap.h> 93 94 #include <sys/sysctl.h> 95 96 #include <limits.h> 97 #include <db.h> 98 #include <paths.h> 99 100 #include "kvm_private.h" 101 102 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) 103 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 104 105 static char *_kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, u_long *); 106 static ssize_t kvm_ureadm(kvm_t *, const struct kinfo_proc *, u_long, char *, size_t); 107 108 static char **kvm_argv(kvm_t *, const struct kinfo_proc *, u_long, int, int, int); 109 110 static char **kvm_doargv(kvm_t *, const struct kinfo_proc *, int, int, 111 void (*)(struct ps_strings *, u_long *, int *)); 112 static int proc_verify(kvm_t *, const struct kinfo_proc *); 113 static void ps_str_a(struct ps_strings *, u_long *, int *); 114 static void ps_str_e(struct ps_strings *, u_long *, int *); 115 116 static struct vm_anon * 117 _kvm_findanon(kvm_t *kd, struct vm_amap *amapp, int slot) 118 { 119 u_long addr; 120 int bucket; 121 struct vm_amap amap; 122 struct vm_amap_chunk chunk, *chunkp; 123 struct vm_anon *anonp; 124 125 addr = (u_long)amapp; 126 if (KREAD(kd, addr, &amap)) 127 return (NULL); 128 129 /* sanity-check slot number */ 130 if (slot > amap.am_nslot) 131 return (NULL); 132 133 if (UVM_AMAP_SMALL(&amap)) 134 chunkp = &amapp->am_small; 135 else { 136 bucket = UVM_AMAP_BUCKET(&amap, slot); 137 addr = (u_long)(amap.am_buckets + bucket); 138 if (KREAD(kd, addr, &chunkp)) 139 return (NULL); 140 141 while (chunkp != NULL) { 142 addr = (u_long)chunkp; 143 if (KREAD(kd, addr, &chunk)) 144 return (NULL); 145 146 if (UVM_AMAP_BUCKET(&amap, chunk.ac_baseslot) != 147 bucket) 148 return (NULL); 149 if (slot >= chunk.ac_baseslot && 150 slot < chunk.ac_baseslot + chunk.ac_nslot) 151 break; 152 153 chunkp = TAILQ_NEXT(&chunk, ac_list); 154 } 155 if (chunkp == NULL) 156 return (NULL); 157 } 158 159 addr = (u_long)&chunkp->ac_anon[UVM_AMAP_SLOTIDX(slot)]; 160 if (KREAD(kd, addr, &anonp)) 161 return (NULL); 162 163 return (anonp); 164 } 165 166 static char * 167 _kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long va, u_long *cnt) 168 { 169 u_long addr, offset, slot; 170 struct vmspace vm; 171 struct vm_anon *anonp, anon; 172 struct vm_map_entry vme; 173 struct vm_page pg; 174 unsigned long rboff; 175 176 if (kd->swapspc == 0) { 177 kd->swapspc = _kvm_malloc(kd, kd->nbpg); 178 if (kd->swapspc == 0) 179 return (NULL); 180 } 181 182 rboff = (unsigned long)&vme.daddrs.addr_entry - (unsigned long)&vme; 183 184 /* 185 * Look through the address map for the memory object 186 * that corresponds to the given virtual address. 187 */ 188 if (KREAD(kd, (u_long)p->p_vmspace, &vm)) 189 return (NULL); 190 addr = (u_long)vm.vm_map.addr.rbh_root.rbt_root; 191 while (1) { 192 if (addr == 0) 193 return (NULL); 194 addr -= rboff; 195 if (KREAD(kd, addr, &vme)) 196 return (NULL); 197 198 if (va < vme.start) 199 addr = (u_long)vme.daddrs.addr_entry.rbt_left; 200 else if (va >= vme.end + vme.guard + vme.fspace) 201 addr = (u_long)vme.daddrs.addr_entry.rbt_right; 202 else if (va >= vme.end) 203 return (NULL); 204 else 205 break; 206 } 207 208 /* 209 * we found the map entry, now to find the object... 210 */ 211 if (vme.aref.ar_amap == NULL) 212 return (NULL); 213 214 offset = va - vme.start; 215 slot = offset / kd->nbpg + vme.aref.ar_pageoff; 216 217 anonp = _kvm_findanon(kd, vme.aref.ar_amap, slot); 218 if (anonp == NULL) 219 return (NULL); 220 221 addr = (u_long)anonp; 222 if (KREAD(kd, addr, &anon)) 223 return (NULL); 224 225 addr = (u_long)anon.an_page; 226 if (addr) { 227 if (KREAD(kd, addr, &pg)) 228 return (NULL); 229 230 if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, 231 (size_t)kd->nbpg, _kvm_pa2off(kd, pg.phys_addr)) != kd->nbpg) 232 return (NULL); 233 } else { 234 if (kd->swfd == -1 || 235 _kvm_pread(kd, kd->swfd, (void *)kd->swapspc, 236 (size_t)kd->nbpg, 237 (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) 238 return (NULL); 239 } 240 241 /* Found the page. */ 242 offset %= kd->nbpg; 243 *cnt = kd->nbpg - offset; 244 return (&kd->swapspc[offset]); 245 } 246 247 void * 248 _kvm_reallocarray(kvm_t *kd, void *p, size_t i, size_t n) 249 { 250 void *np = reallocarray(p, i, n); 251 252 if (np == 0) 253 _kvm_err(kd, kd->program, "out of memory"); 254 return (np); 255 } 256 257 /* 258 * Read in an argument vector from the user address space of process p. 259 * addr if the user-space base address of narg null-terminated contiguous 260 * strings. This is used to read in both the command arguments and 261 * environment strings. Read at most maxcnt characters of strings. 262 */ 263 static char ** 264 kvm_argv(kvm_t *kd, const struct kinfo_proc *p, u_long addr, int narg, 265 int maxcnt, int isenv) 266 { 267 char *np, *cp, *ep, *ap, **argv, ***pargv, **pargspc, **pargbuf; 268 u_long oaddr = -1; 269 int len, cc, *parglen, *pargc; 270 size_t argc; 271 272 /* 273 * Check that there aren't an unreasonable number of arguments, 274 * and that the address is in user space. 275 */ 276 if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS) 277 return (0); 278 279 if (isenv) { 280 pargspc = &kd->envspc; 281 pargbuf = &kd->envbuf; 282 parglen = &kd->envlen; 283 pargv = &kd->envp; 284 pargc = &kd->envc; 285 } else { 286 pargspc = &kd->argspc; 287 pargbuf = &kd->argbuf; 288 parglen = &kd->arglen; 289 pargv = &kd->argv; 290 pargc = &kd->argc; 291 } 292 293 if (*pargv == 0) 294 argc = MAXIMUM(narg + 1, 32); 295 else if (narg + 1 > *pargc) 296 argc = MAXIMUM(2 * (*pargc), narg + 1); 297 else 298 goto argv_allocated; 299 argv = _kvm_reallocarray(kd, *pargv, argc, sizeof(**pargv)); 300 if (argv == 0) 301 return (0); 302 *pargv = argv; 303 *pargc = argc; 304 305 argv_allocated: 306 if (*pargspc == 0) { 307 *pargspc = _kvm_malloc(kd, kd->nbpg); 308 if (*pargspc == 0) 309 return (0); 310 *parglen = kd->nbpg; 311 } 312 if (*pargbuf == 0) { 313 *pargbuf = _kvm_malloc(kd, kd->nbpg); 314 if (*pargbuf == 0) 315 return (0); 316 } 317 cc = sizeof(char *) * narg; 318 if (kvm_ureadm(kd, p, addr, (char *)*pargv, cc) != cc) 319 return (0); 320 ap = np = *pargspc; 321 argv = *pargv; 322 len = 0; 323 324 /* 325 * Loop over pages, filling in the argument vector. 326 */ 327 while (argv < *pargv + narg && *argv != 0) { 328 addr = (u_long)*argv & ~(kd->nbpg - 1); 329 if (addr != oaddr) { 330 if (kvm_ureadm(kd, p, addr, *pargbuf, kd->nbpg) != 331 kd->nbpg) 332 return (0); 333 oaddr = addr; 334 } 335 addr = (u_long)*argv & (kd->nbpg - 1); 336 cp = *pargbuf + addr; 337 cc = kd->nbpg - addr; 338 if (maxcnt > 0 && cc > maxcnt - len) 339 cc = maxcnt - len; 340 ep = memchr(cp, '\0', cc); 341 if (ep != 0) 342 cc = ep - cp + 1; 343 if (len + cc > *parglen) { 344 ptrdiff_t off; 345 char **pp; 346 char *op = *pargspc; 347 char *newp; 348 349 newp = _kvm_reallocarray(kd, *pargspc, 350 *parglen, 2); 351 if (newp == 0) 352 return (0); 353 *pargspc = newp; 354 *parglen *= 2; 355 /* 356 * Adjust argv pointers in case realloc moved 357 * the string space. 358 */ 359 off = *pargspc - op; 360 for (pp = *pargv; pp < argv; pp++) 361 *pp += off; 362 ap += off; 363 np += off; 364 } 365 memcpy(np, cp, cc); 366 np += cc; 367 len += cc; 368 if (ep != 0) { 369 *argv++ = ap; 370 ap = np; 371 } else 372 *argv += cc; 373 if (maxcnt > 0 && len >= maxcnt) { 374 /* 375 * We're stopping prematurely. Terminate the 376 * current string. 377 */ 378 if (ep == 0) { 379 *np = '\0'; 380 *argv++ = ap; 381 } 382 break; 383 } 384 } 385 /* Make sure argv is terminated. */ 386 *argv = 0; 387 return (*pargv); 388 } 389 390 static void 391 ps_str_a(struct ps_strings *p, u_long *addr, int *n) 392 { 393 *addr = (u_long)p->ps_argvstr; 394 *n = p->ps_nargvstr; 395 } 396 397 static void 398 ps_str_e(struct ps_strings *p, u_long *addr, int *n) 399 { 400 *addr = (u_long)p->ps_envstr; 401 *n = p->ps_nenvstr; 402 } 403 404 /* 405 * Determine if the proc indicated by p is still active. 406 * This test is not 100% foolproof in theory, but chances of 407 * being wrong are very low. 408 */ 409 static int 410 proc_verify(kvm_t *kd, const struct kinfo_proc *p) 411 { 412 struct proc kernproc; 413 struct process kernprocess; 414 415 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE)) 416 return (0); 417 418 /* 419 * Just read in the whole proc. It's not that big relative 420 * to the cost of the read system call. 421 */ 422 if (KREAD(kd, (u_long)p->p_paddr, &kernproc)) 423 return (0); 424 if (KREAD(kd, (u_long)kernproc.p_p, &kernprocess)) 425 return (0); 426 if (p->p_pid != kernprocess.ps_pid) 427 return (0); 428 return ((kernprocess.ps_flags & (PS_EMBRYO | PS_ZOMBIE)) == 0); 429 } 430 431 static char ** 432 kvm_doargv(kvm_t *kd, const struct kinfo_proc *p, int nchr, int isenv, 433 void (*info)(struct ps_strings *, u_long *, int *)) 434 { 435 struct proc pp; 436 struct process pr; 437 struct ps_strings *ps; 438 struct ps_strings arginfo; 439 u_long addr; 440 char **ap; 441 int cnt; 442 443 /* get ps_strings address */ 444 if (KREAD(kd, (u_long)p->p_paddr, &pp)) 445 return (0); 446 if (KREAD(kd, (u_long)pp.p_p, &pr)) 447 return (0); 448 ps = (struct ps_strings *)pr.ps_strings; 449 450 /* 451 * Pointers are stored at the top of the user stack. 452 */ 453 if (p->p_psflags & (PS_EMBRYO | PS_ZOMBIE) || 454 kvm_ureadm(kd, p, (u_long)ps, (char *)&arginfo, 455 sizeof(arginfo)) != sizeof(arginfo)) 456 return (0); 457 458 (*info)(&arginfo, &addr, &cnt); 459 if (cnt == 0) 460 return (0); 461 ap = kvm_argv(kd, p, addr, cnt, nchr, isenv); 462 /* 463 * For live kernels, make sure this process didn't go away. 464 */ 465 if (ap != 0 && ISALIVE(kd) && !proc_verify(kd, p)) 466 ap = 0; 467 return (ap); 468 } 469 470 static char ** 471 kvm_arg_sysctl(kvm_t *kd, pid_t pid, int nchr, int isenv) 472 { 473 size_t len, orglen; 474 int mib[4], ret; 475 char *buf, **pargbuf; 476 477 if (isenv) { 478 pargbuf = &kd->envbuf; 479 orglen = kd->nbpg; 480 } else { 481 pargbuf = &kd->argbuf; 482 orglen = 8 * kd->nbpg; /* XXX - should be ARG_MAX */ 483 } 484 if (*pargbuf == NULL && 485 (*pargbuf = _kvm_malloc(kd, orglen)) == NULL) 486 return (NULL); 487 488 again: 489 mib[0] = CTL_KERN; 490 mib[1] = KERN_PROC_ARGS; 491 mib[2] = (int)pid; 492 mib[3] = isenv ? KERN_PROC_ENV : KERN_PROC_ARGV; 493 494 len = orglen; 495 ret = (sysctl(mib, 4, *pargbuf, &len, NULL, 0) == -1); 496 if (ret && errno == ENOMEM) { 497 buf = _kvm_reallocarray(kd, *pargbuf, orglen, 2); 498 if (buf == NULL) 499 return (NULL); 500 orglen *= 2; 501 *pargbuf = buf; 502 goto again; 503 } 504 505 if (ret) { 506 free(*pargbuf); 507 *pargbuf = NULL; 508 _kvm_syserr(kd, kd->program, "kvm_arg_sysctl"); 509 return (NULL); 510 } 511 #if 0 512 for (argv = (char **)*pargbuf; *argv != NULL; argv++) 513 if (strlen(*argv) > nchr) 514 *argv[nchr] = '\0'; 515 #endif 516 517 return (char **)(*pargbuf); 518 } 519 520 /* 521 * Get the command args. This code is now machine independent. 522 */ 523 char ** 524 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 525 { 526 if (ISALIVE(kd)) 527 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 0)); 528 return (kvm_doargv(kd, kp, nchr, 0, ps_str_a)); 529 } 530 531 char ** 532 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr) 533 { 534 if (ISALIVE(kd)) 535 return (kvm_arg_sysctl(kd, kp->p_pid, nchr, 1)); 536 return (kvm_doargv(kd, kp, nchr, 1, ps_str_e)); 537 } 538 539 /* 540 * Read from user space. The user context is given by p. 541 */ 542 static ssize_t 543 kvm_ureadm(kvm_t *kd, const struct kinfo_proc *p, u_long uva, char *buf, 544 size_t len) 545 { 546 char *cp = buf; 547 548 while (len > 0) { 549 u_long cnt; 550 size_t cc; 551 char *dp; 552 553 dp = _kvm_ureadm(kd, p, uva, &cnt); 554 if (dp == 0) { 555 _kvm_err(kd, 0, "invalid address (%lx)", uva); 556 return (0); 557 } 558 cc = (size_t)MINIMUM(cnt, len); 559 memcpy(cp, dp, cc); 560 cp += cc; 561 uva += cc; 562 len -= cc; 563 } 564 return (ssize_t)(cp - buf); 565 } 566