1 /*- 2 * Copyright (c) 2008-2009, Stacey Son <sson@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 33 #include <sys/conf.h> 34 #include <sys/elf.h> 35 #include <sys/ksyms.h> 36 #include <sys/linker.h> 37 #include <sys/malloc.h> 38 #include <sys/mman.h> 39 #include <sys/module.h> 40 #include <sys/mutex.h> 41 #include <sys/proc.h> 42 #include <sys/queue.h> 43 #include <sys/resourcevar.h> 44 #include <sys/stat.h> 45 #include <sys/uio.h> 46 47 #include <machine/elf.h> 48 49 #include <vm/pmap.h> 50 #include <vm/vm.h> 51 #include <vm/vm_extern.h> 52 #include <vm/vm_map.h> 53 54 #include "linker_if.h" 55 56 #define SHDR_NULL 0 57 #define SHDR_SYMTAB 1 58 #define SHDR_STRTAB 2 59 #define SHDR_SHSTRTAB 3 60 61 #define SHDR_NUM 4 62 63 #define STR_SYMTAB ".symtab" 64 #define STR_STRTAB ".strtab" 65 #define STR_SHSTRTAB ".shstrtab" 66 67 #define KSYMS_DNAME "ksyms" 68 69 static d_open_t ksyms_open; 70 static d_read_t ksyms_read; 71 static d_close_t ksyms_close; 72 static d_ioctl_t ksyms_ioctl; 73 static d_mmap_t ksyms_mmap; 74 75 static struct cdevsw ksyms_cdevsw = { 76 .d_version = D_VERSION, 77 .d_flags = D_PSEUDO | D_TRACKCLOSE, 78 .d_open = ksyms_open, 79 .d_close = ksyms_close, 80 .d_read = ksyms_read, 81 .d_ioctl = ksyms_ioctl, 82 .d_mmap = ksyms_mmap, 83 .d_name = KSYMS_DNAME 84 }; 85 86 struct ksyms_softc { 87 LIST_ENTRY(ksyms_softc) sc_list; 88 vm_offset_t sc_uaddr; 89 size_t sc_usize; 90 pmap_t sc_pmap; 91 struct proc *sc_proc; 92 }; 93 94 static struct mtx ksyms_mtx; 95 static struct cdev *ksyms_dev; 96 static LIST_HEAD(, ksyms_softc) ksyms_list = 97 LIST_HEAD_INITIALIZER(&ksyms_list); 98 99 static const char ksyms_shstrtab[] = 100 "\0" STR_SYMTAB "\0" STR_STRTAB "\0" STR_SHSTRTAB "\0"; 101 102 struct ksyms_hdr { 103 Elf_Ehdr kh_ehdr; 104 Elf_Phdr kh_txtphdr; 105 Elf_Phdr kh_datphdr; 106 Elf_Shdr kh_shdr[SHDR_NUM]; 107 char kh_shstrtab[sizeof(ksyms_shstrtab)]; 108 }; 109 110 struct tsizes { 111 size_t ts_symsz; 112 size_t ts_strsz; 113 }; 114 115 struct toffsets { 116 vm_offset_t to_symoff; 117 vm_offset_t to_stroff; 118 unsigned to_stridx; 119 size_t to_resid; 120 }; 121 122 static MALLOC_DEFINE(M_KSYMS, "KSYMS", "Kernel Symbol Table"); 123 124 /* 125 * Get the symbol and string table sizes for a kernel module. Add it to the 126 * running total. 127 */ 128 static int 129 ksyms_size_permod(linker_file_t lf, void *arg) 130 { 131 struct tsizes *ts; 132 Elf_Sym *symtab; 133 caddr_t strtab; 134 long syms; 135 136 ts = arg; 137 138 syms = LINKER_SYMTAB_GET(lf, &symtab); 139 ts->ts_symsz += syms * sizeof(Elf_Sym); 140 ts->ts_strsz += LINKER_STRTAB_GET(lf, &strtab); 141 142 return (0); 143 } 144 145 /* 146 * For kernel module get the symbol and string table sizes, returning the 147 * totals in *ts. 148 */ 149 static void 150 ksyms_size_calc(struct tsizes *ts) 151 { 152 ts->ts_symsz = 0; 153 ts->ts_strsz = 0; 154 155 (void) linker_file_foreach(ksyms_size_permod, ts); 156 } 157 158 #define KSYMS_EMIT(src, des, sz) do { \ 159 copyout(src, (void *)des, sz); \ 160 des += sz; \ 161 } while (0) 162 163 #define SYMBLKSZ 256 * sizeof (Elf_Sym) 164 165 /* 166 * For a kernel module, add the symbol and string tables into the 167 * snapshot buffer. Fix up the offsets in the tables. 168 */ 169 static int 170 ksyms_add(linker_file_t lf, void *arg) 171 { 172 struct toffsets *to; 173 Elf_Sym *symtab, *symp; 174 caddr_t strtab; 175 long symsz; 176 size_t strsz, numsyms; 177 linker_symval_t symval; 178 char *buf; 179 int i, nsyms, len; 180 181 to = arg; 182 183 MOD_SLOCK; 184 numsyms = LINKER_SYMTAB_GET(lf, &symtab); 185 strsz = LINKER_STRTAB_GET(lf, &strtab); 186 symsz = numsyms * sizeof(Elf_Sym); 187 188 buf = malloc(SYMBLKSZ, M_KSYMS, M_WAITOK); 189 190 while (symsz > 0) { 191 len = min(SYMBLKSZ, symsz); 192 bcopy(symtab, buf, len); 193 194 /* 195 * Fix up symbol table for kernel modules: 196 * string offsets need adjusted 197 * symbol values made absolute 198 */ 199 symp = (Elf_Sym *) buf; 200 nsyms = len / sizeof (Elf_Sym); 201 for (i = 0; i < nsyms; i++) { 202 symp[i].st_name += to->to_stridx; 203 if (lf->id > 1 && LINKER_SYMBOL_VALUES(lf, 204 (c_linker_sym_t) &symtab[i], &symval) == 0) { 205 symp[i].st_value = (uintptr_t) symval.value; 206 } 207 } 208 209 if (len > to->to_resid) { 210 MOD_SUNLOCK; 211 free(buf, M_KSYMS); 212 return (ENXIO); 213 } else 214 to->to_resid -= len; 215 KSYMS_EMIT(buf, to->to_symoff, len); 216 217 symtab += nsyms; 218 symsz -= len; 219 } 220 free(buf, M_KSYMS); 221 MOD_SUNLOCK; 222 223 if (strsz > to->to_resid) 224 return (ENXIO); 225 else 226 to->to_resid -= strsz; 227 KSYMS_EMIT(strtab, to->to_stroff, strsz); 228 to->to_stridx += strsz; 229 230 return (0); 231 } 232 233 /* 234 * Create a single ELF symbol table for the kernel and kernel modules loaded 235 * at this time. Write this snapshot out in the process address space. Return 236 * 0 on success, otherwise error. 237 */ 238 static int 239 ksyms_snapshot(struct tsizes *ts, vm_offset_t uaddr, size_t resid) 240 { 241 242 struct ksyms_hdr *hdr; 243 struct toffsets to; 244 int error = 0; 245 246 /* Be kernel stack friendly */ 247 hdr = malloc(sizeof (*hdr), M_KSYMS, M_WAITOK|M_ZERO); 248 249 /* 250 * Create the ELF header. 251 */ 252 hdr->kh_ehdr.e_ident[EI_PAD] = 0; 253 hdr->kh_ehdr.e_ident[EI_MAG0] = ELFMAG0; 254 hdr->kh_ehdr.e_ident[EI_MAG1] = ELFMAG1; 255 hdr->kh_ehdr.e_ident[EI_MAG2] = ELFMAG2; 256 hdr->kh_ehdr.e_ident[EI_MAG3] = ELFMAG3; 257 hdr->kh_ehdr.e_ident[EI_DATA] = ELF_DATA; 258 hdr->kh_ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD; 259 hdr->kh_ehdr.e_ident[EI_CLASS] = ELF_CLASS; 260 hdr->kh_ehdr.e_ident[EI_VERSION] = EV_CURRENT; 261 hdr->kh_ehdr.e_ident[EI_ABIVERSION] = 0; 262 hdr->kh_ehdr.e_type = ET_EXEC; 263 hdr->kh_ehdr.e_machine = ELF_ARCH; 264 hdr->kh_ehdr.e_version = EV_CURRENT; 265 hdr->kh_ehdr.e_entry = 0; 266 hdr->kh_ehdr.e_phoff = offsetof(struct ksyms_hdr, kh_txtphdr); 267 hdr->kh_ehdr.e_shoff = offsetof(struct ksyms_hdr, kh_shdr); 268 hdr->kh_ehdr.e_flags = 0; 269 hdr->kh_ehdr.e_ehsize = sizeof(Elf_Ehdr); 270 hdr->kh_ehdr.e_phentsize = sizeof(Elf_Phdr); 271 hdr->kh_ehdr.e_phnum = 2; /* Text and Data */ 272 hdr->kh_ehdr.e_shentsize = sizeof(Elf_Shdr); 273 hdr->kh_ehdr.e_shnum = SHDR_NUM; 274 hdr->kh_ehdr.e_shstrndx = SHDR_SHSTRTAB; 275 276 /* 277 * Add both the text and data Program headers. 278 */ 279 hdr->kh_txtphdr.p_type = PT_LOAD; 280 /* XXX - is there a way to put the actual .text addr/size here? */ 281 hdr->kh_txtphdr.p_vaddr = 0; 282 hdr->kh_txtphdr.p_memsz = 0; 283 hdr->kh_txtphdr.p_flags = PF_R | PF_X; 284 285 hdr->kh_datphdr.p_type = PT_LOAD; 286 /* XXX - is there a way to put the actual .data addr/size here? */ 287 hdr->kh_datphdr.p_vaddr = 0; 288 hdr->kh_datphdr.p_memsz = 0; 289 hdr->kh_datphdr.p_flags = PF_R | PF_W | PF_X; 290 291 /* 292 * Add the Section headers: null, symtab, strtab, shstrtab, 293 */ 294 295 /* First section header - null */ 296 297 /* Second section header - symtab */ 298 hdr->kh_shdr[SHDR_SYMTAB].sh_name = 1; /* String offset (skip null) */ 299 hdr->kh_shdr[SHDR_SYMTAB].sh_type = SHT_SYMTAB; 300 hdr->kh_shdr[SHDR_SYMTAB].sh_flags = 0; 301 hdr->kh_shdr[SHDR_SYMTAB].sh_addr = 0; 302 hdr->kh_shdr[SHDR_SYMTAB].sh_offset = sizeof(*hdr); 303 hdr->kh_shdr[SHDR_SYMTAB].sh_size = ts->ts_symsz; 304 hdr->kh_shdr[SHDR_SYMTAB].sh_link = SHDR_STRTAB; 305 hdr->kh_shdr[SHDR_SYMTAB].sh_info = ts->ts_symsz / sizeof(Elf_Sym); 306 hdr->kh_shdr[SHDR_SYMTAB].sh_addralign = sizeof(long); 307 hdr->kh_shdr[SHDR_SYMTAB].sh_entsize = sizeof(Elf_Sym); 308 309 /* Third section header - strtab */ 310 hdr->kh_shdr[SHDR_STRTAB].sh_name = 1 + sizeof(STR_SYMTAB); 311 hdr->kh_shdr[SHDR_STRTAB].sh_type = SHT_STRTAB; 312 hdr->kh_shdr[SHDR_STRTAB].sh_flags = 0; 313 hdr->kh_shdr[SHDR_STRTAB].sh_addr = 0; 314 hdr->kh_shdr[SHDR_STRTAB].sh_offset = 315 hdr->kh_shdr[SHDR_SYMTAB].sh_offset + ts->ts_symsz; 316 hdr->kh_shdr[SHDR_STRTAB].sh_size = ts->ts_strsz; 317 hdr->kh_shdr[SHDR_STRTAB].sh_link = 0; 318 hdr->kh_shdr[SHDR_STRTAB].sh_info = 0; 319 hdr->kh_shdr[SHDR_STRTAB].sh_addralign = sizeof(char); 320 hdr->kh_shdr[SHDR_STRTAB].sh_entsize = 0; 321 322 /* Fourth section - shstrtab */ 323 hdr->kh_shdr[SHDR_SHSTRTAB].sh_name = 1 + sizeof(STR_SYMTAB) + 324 sizeof(STR_STRTAB); 325 hdr->kh_shdr[SHDR_SHSTRTAB].sh_type = SHT_STRTAB; 326 hdr->kh_shdr[SHDR_SHSTRTAB].sh_flags = 0; 327 hdr->kh_shdr[SHDR_SHSTRTAB].sh_addr = 0; 328 hdr->kh_shdr[SHDR_SHSTRTAB].sh_offset = 329 offsetof(struct ksyms_hdr, kh_shstrtab); 330 hdr->kh_shdr[SHDR_SHSTRTAB].sh_size = sizeof(ksyms_shstrtab); 331 hdr->kh_shdr[SHDR_SHSTRTAB].sh_link = 0; 332 hdr->kh_shdr[SHDR_SHSTRTAB].sh_info = 0; 333 hdr->kh_shdr[SHDR_SHSTRTAB].sh_addralign = 0 /* sizeof(char) */; 334 hdr->kh_shdr[SHDR_SHSTRTAB].sh_entsize = 0; 335 336 /* Copy shstrtab into the header */ 337 bcopy(ksyms_shstrtab, hdr->kh_shstrtab, sizeof(ksyms_shstrtab)); 338 339 to.to_symoff = uaddr + hdr->kh_shdr[SHDR_SYMTAB].sh_offset; 340 to.to_stroff = uaddr + hdr->kh_shdr[SHDR_STRTAB].sh_offset; 341 to.to_stridx = 0; 342 if (sizeof(struct ksyms_hdr) > resid) { 343 free(hdr, M_KSYMS); 344 return (ENXIO); 345 } 346 to.to_resid = resid - sizeof(struct ksyms_hdr); 347 348 /* Emit Header */ 349 copyout(hdr, (void *)uaddr, sizeof(struct ksyms_hdr)); 350 351 free(hdr, M_KSYMS); 352 353 /* Add symbol and string tables for each kernelmodule */ 354 error = linker_file_foreach(ksyms_add, &to); 355 356 if (to.to_resid != 0) 357 return (ENXIO); 358 359 return (error); 360 } 361 362 /* 363 * Map some anonymous memory in user space of size sz, rounded up to the page 364 * boundary. 365 */ 366 static int 367 ksyms_map(struct thread *td, vm_offset_t *addr, size_t sz) 368 { 369 struct vmspace *vms = td->td_proc->p_vmspace; 370 int error; 371 vm_size_t size; 372 373 374 /* 375 * Map somewhere after heap in process memory. 376 */ 377 PROC_LOCK(td->td_proc); 378 *addr = round_page((vm_offset_t)vms->vm_daddr + 379 lim_max(td->td_proc, RLIMIT_DATA)); 380 PROC_UNLOCK(td->td_proc); 381 382 /* round size up to page boundry */ 383 size = (vm_size_t) round_page(sz); 384 385 error = vm_mmap(&vms->vm_map, addr, size, PROT_READ | PROT_WRITE, 386 VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, OBJT_DEFAULT, NULL, 0); 387 388 return (error); 389 } 390 391 /* 392 * Unmap memory in user space. 393 */ 394 static int 395 ksyms_unmap(struct thread *td, vm_offset_t addr, size_t sz) 396 { 397 vm_map_t map; 398 vm_size_t size; 399 400 map = &td->td_proc->p_vmspace->vm_map; 401 size = (vm_size_t) round_page(sz); 402 403 if (!vm_map_remove(map, addr, addr + size)) 404 return (EINVAL); 405 406 return (0); 407 } 408 409 static void 410 ksyms_cdevpriv_dtr(void *data) 411 { 412 struct ksyms_softc *sc; 413 414 sc = (struct ksyms_softc *)data; 415 416 mtx_lock(&ksyms_mtx); 417 LIST_REMOVE(sc, sc_list); 418 mtx_unlock(&ksyms_mtx); 419 free(sc, M_KSYMS); 420 } 421 422 /* ARGSUSED */ 423 static int 424 ksyms_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td) 425 { 426 struct tsizes ts; 427 size_t total_elf_sz; 428 int error, try; 429 struct ksyms_softc *sc; 430 431 /* 432 * Limit one open() per process. The process must close() 433 * before open()'ing again. 434 */ 435 mtx_lock(&ksyms_mtx); 436 LIST_FOREACH(sc, &ksyms_list, sc_list) { 437 if (sc->sc_proc == td->td_proc) { 438 mtx_unlock(&ksyms_mtx); 439 return (EBUSY); 440 } 441 } 442 443 sc = (struct ksyms_softc *) malloc(sizeof (*sc), M_KSYMS, 444 M_NOWAIT|M_ZERO); 445 446 if (sc == NULL) { 447 mtx_unlock(&ksyms_mtx); 448 return (ENOMEM); 449 } 450 sc->sc_proc = td->td_proc; 451 sc->sc_pmap = &td->td_proc->p_vmspace->vm_pmap; 452 LIST_INSERT_HEAD(&ksyms_list, sc, sc_list); 453 mtx_unlock(&ksyms_mtx); 454 455 error = devfs_set_cdevpriv(sc, ksyms_cdevpriv_dtr); 456 if (error) 457 goto failed; 458 459 /* 460 * MOD_SLOCK doesn't work here (because of a lock reversal with 461 * KLD_SLOCK). Therefore, simply try upto 3 times to get a "clean" 462 * snapshot of the kernel symbol table. This should work fine in the 463 * rare case of a kernel module being loaded/unloaded at the same 464 * time. 465 */ 466 for(try = 0; try < 3; try++) { 467 /* 468 * Map a buffer in the calling process memory space and 469 * create a snapshot of the kernel symbol table in it. 470 */ 471 472 /* Compute the size of buffer needed. */ 473 ksyms_size_calc(&ts); 474 total_elf_sz = sizeof(struct ksyms_hdr) + ts.ts_symsz + 475 ts.ts_strsz; 476 477 error = ksyms_map(td, &(sc->sc_uaddr), 478 (vm_size_t) total_elf_sz); 479 if (error) 480 break; 481 sc->sc_usize = total_elf_sz; 482 483 error = ksyms_snapshot(&ts, sc->sc_uaddr, total_elf_sz); 484 if (!error) { 485 /* Successful Snapshot */ 486 return (0); 487 } 488 489 /* Snapshot failed, unmap the memory and try again */ 490 (void) ksyms_unmap(td, sc->sc_uaddr, sc->sc_usize); 491 } 492 493 failed: 494 ksyms_cdevpriv_dtr(sc); 495 return (error); 496 } 497 498 /* ARGSUSED */ 499 static int 500 ksyms_read(struct cdev *dev, struct uio *uio, int flags __unused) 501 { 502 int error; 503 size_t len, sz; 504 struct ksyms_softc *sc; 505 off_t off; 506 char *buf; 507 vm_size_t ubase; 508 509 error = devfs_get_cdevpriv((void **)&sc); 510 if (error) 511 return (error); 512 513 off = uio->uio_offset; 514 len = uio->uio_resid; 515 516 if (off < 0 || off > sc->sc_usize) 517 return (EFAULT); 518 519 if (len > (sc->sc_usize - off)) 520 len = sc->sc_usize - off; 521 522 if (len == 0) 523 return (0); 524 525 /* 526 * Since the snapshot buffer is in the user space we have to copy it 527 * in to the kernel and then back out. The extra copy saves valuable 528 * kernel memory. 529 */ 530 buf = malloc(PAGE_SIZE, M_KSYMS, M_WAITOK); 531 ubase = sc->sc_uaddr + off; 532 533 while (len) { 534 535 sz = min(PAGE_SIZE, len); 536 if (copyin((void *)ubase, buf, sz)) 537 error = EFAULT; 538 else 539 error = uiomove(buf, sz, uio); 540 541 if (error) 542 break; 543 544 len -= sz; 545 ubase += sz; 546 } 547 free(buf, M_KSYMS); 548 549 return (error); 550 } 551 552 /* ARGSUSED */ 553 static int 554 ksyms_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int32_t flag __unused, 555 struct thread *td __unused) 556 { 557 int error = 0; 558 struct ksyms_softc *sc; 559 560 error = devfs_get_cdevpriv((void **)&sc); 561 if (error) 562 return (error); 563 564 switch (cmd) { 565 case KIOCGSIZE: 566 /* 567 * Return the size (in bytes) of the symbol table 568 * snapshot. 569 */ 570 *(size_t *)data = sc->sc_usize; 571 break; 572 573 case KIOCGADDR: 574 /* 575 * Return the address of the symbol table snapshot. 576 * XXX - compat32 version of this? 577 */ 578 *(void **)data = (void *)sc->sc_uaddr; 579 break; 580 581 default: 582 error = ENOTTY; 583 break; 584 } 585 586 return (error); 587 } 588 589 /* ARGUSED */ 590 static int 591 ksyms_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, 592 int prot __unused) 593 { 594 struct ksyms_softc *sc; 595 int error; 596 597 error = devfs_get_cdevpriv((void **)&sc); 598 if (error) 599 return (error); 600 601 /* 602 * XXX mmap() will actually map the symbol table into the process 603 * address space again. 604 */ 605 if (offset > round_page(sc->sc_usize) || 606 (*paddr = pmap_extract(sc->sc_pmap, 607 (vm_offset_t)sc->sc_uaddr + offset)) == 0) 608 return (-1); 609 610 return (0); 611 } 612 613 /* ARGUSED */ 614 static int 615 ksyms_close(struct cdev *dev, int flags __unused, int fmt __unused, 616 struct thread *td) 617 { 618 int error = 0; 619 struct ksyms_softc *sc; 620 621 error = devfs_get_cdevpriv((void **)&sc); 622 if (error) 623 return (error); 624 625 /* Unmap the buffer from the process address space. */ 626 error = ksyms_unmap(td, sc->sc_uaddr, sc->sc_usize); 627 628 devfs_clear_cdevpriv(); 629 630 return (error); 631 } 632 633 /* ARGSUSED */ 634 static int 635 ksyms_modevent(module_t mod __unused, int type, void *data __unused) 636 { 637 int error = 0; 638 639 switch (type) { 640 case MOD_LOAD: 641 mtx_init(&ksyms_mtx, "KSyms mtx", NULL, MTX_DEF); 642 ksyms_dev = make_dev(&ksyms_cdevsw, 0, UID_ROOT, GID_WHEEL, 643 0444, KSYMS_DNAME); 644 break; 645 646 case MOD_UNLOAD: 647 if (!LIST_EMPTY(&ksyms_list)) 648 return (EBUSY); 649 destroy_dev(ksyms_dev); 650 mtx_destroy(&ksyms_mtx); 651 break; 652 653 case MOD_SHUTDOWN: 654 break; 655 656 default: 657 error = EOPNOTSUPP; 658 break; 659 } 660 return (error); 661 } 662 663 DEV_MODULE(ksyms, ksyms_modevent, NULL); 664 MODULE_VERSION(ksyms, 1); 665