| 1 | /* $NetBSD: kern_ksyms.c,v 1.84 2016/07/07 06:55:43 msaitoh Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2008 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software developed for The NetBSD Foundation |
| 8 | * by Andrew Doran. |
| 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 | /* |
| 33 | * Copyright (c) 2001, 2003 Anders Magnusson (ragge@ludd.luth.se). |
| 34 | * All rights reserved. |
| 35 | * |
| 36 | * Redistribution and use in source and binary forms, with or without |
| 37 | * modification, are permitted provided that the following conditions |
| 38 | * are met: |
| 39 | * 1. Redistributions of source code must retain the above copyright |
| 40 | * notice, this list of conditions and the following disclaimer. |
| 41 | * 2. Redistributions in binary form must reproduce the above copyright |
| 42 | * notice, this list of conditions and the following disclaimer in the |
| 43 | * documentation and/or other materials provided with the distribution. |
| 44 | * 3. The name of the author may not be used to endorse or promote products |
| 45 | * derived from this software without specific prior written permission |
| 46 | * |
| 47 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 48 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 49 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 50 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 51 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 52 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 53 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 54 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 55 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 56 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 57 | */ |
| 58 | |
| 59 | /* |
| 60 | * Code to deal with in-kernel symbol table management + /dev/ksyms. |
| 61 | * |
| 62 | * For each loaded module the symbol table info is kept track of by a |
| 63 | * struct, placed in a circular list. The first entry is the kernel |
| 64 | * symbol table. |
| 65 | */ |
| 66 | |
| 67 | /* |
| 68 | * TODO: |
| 69 | * |
| 70 | * Add support for mmap, poll. |
| 71 | * Constify tables. |
| 72 | * Constify db_symtab and move it to .rodata. |
| 73 | */ |
| 74 | |
| 75 | #include <sys/cdefs.h> |
| 76 | __KERNEL_RCSID(0, "$NetBSD: kern_ksyms.c,v 1.84 2016/07/07 06:55:43 msaitoh Exp $" ); |
| 77 | |
| 78 | #if defined(_KERNEL) && defined(_KERNEL_OPT) |
| 79 | #include "opt_copy_symtab.h" |
| 80 | #include "opt_ddb.h" |
| 81 | #include "opt_dtrace.h" |
| 82 | #endif |
| 83 | |
| 84 | #define _KSYMS_PRIVATE |
| 85 | |
| 86 | #include <sys/param.h> |
| 87 | #include <sys/queue.h> |
| 88 | #include <sys/exec.h> |
| 89 | #include <sys/systm.h> |
| 90 | #include <sys/conf.h> |
| 91 | #include <sys/kmem.h> |
| 92 | #include <sys/proc.h> |
| 93 | #include <sys/atomic.h> |
| 94 | #include <sys/ksyms.h> |
| 95 | |
| 96 | #ifdef DDB |
| 97 | #include <ddb/db_output.h> |
| 98 | #endif |
| 99 | |
| 100 | #include "ksyms.h" |
| 101 | #if NKSYMS > 0 |
| 102 | #include "ioconf.h" |
| 103 | #endif |
| 104 | |
| 105 | #define KSYMS_MAX_ID 98304 |
| 106 | #ifdef KDTRACE_HOOKS |
| 107 | static uint32_t ksyms_nmap[KSYMS_MAX_ID]; /* sorted symbol table map */ |
| 108 | #else |
| 109 | static uint32_t *ksyms_nmap = NULL; |
| 110 | #endif |
| 111 | |
| 112 | static int ksyms_maxlen; |
| 113 | static bool ksyms_isopen; |
| 114 | static bool ksyms_initted; |
| 115 | static bool ksyms_loaded; |
| 116 | static kmutex_t ksyms_lock __cacheline_aligned; |
| 117 | static struct ksyms_symtab kernel_symtab; |
| 118 | |
| 119 | static void ksyms_hdr_init(const void *); |
| 120 | static void ksyms_sizes_calc(void); |
| 121 | |
| 122 | #ifdef KSYMS_DEBUG |
| 123 | #define FOLLOW_CALLS 1 |
| 124 | #define FOLLOW_MORE_CALLS 2 |
| 125 | #define FOLLOW_DEVKSYMS 4 |
| 126 | static int ksyms_debug; |
| 127 | #endif |
| 128 | |
| 129 | #define SYMTAB_FILLER "|This is the symbol table!" |
| 130 | |
| 131 | #ifdef makeoptions_COPY_SYMTAB |
| 132 | extern char db_symtab[]; |
| 133 | extern int db_symtabsize; |
| 134 | #endif |
| 135 | |
| 136 | /* |
| 137 | * used by savecore(8) so non-static |
| 138 | */ |
| 139 | struct ksyms_hdr ksyms_hdr; |
| 140 | int ksyms_symsz; |
| 141 | int ksyms_strsz; |
| 142 | int ksyms_ctfsz; /* this is not currently used by savecore(8) */ |
| 143 | TAILQ_HEAD(, ksyms_symtab) ksyms_symtabs = |
| 144 | TAILQ_HEAD_INITIALIZER(ksyms_symtabs); |
| 145 | |
| 146 | static int |
| 147 | ksyms_verify(const void *symstart, const void *strstart) |
| 148 | { |
| 149 | #if defined(DIAGNOSTIC) || defined(DEBUG) |
| 150 | if (symstart == NULL) |
| 151 | printf("ksyms: Symbol table not found\n" ); |
| 152 | if (strstart == NULL) |
| 153 | printf("ksyms: String table not found\n" ); |
| 154 | if (symstart == NULL || strstart == NULL) |
| 155 | printf("ksyms: Perhaps the kernel is stripped?\n" ); |
| 156 | #endif |
| 157 | if (symstart == NULL || strstart == NULL) |
| 158 | return 0; |
| 159 | return 1; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * Finds a certain symbol name in a certain symbol table. |
| 164 | */ |
| 165 | static Elf_Sym * |
| 166 | findsym(const char *name, struct ksyms_symtab *table, int type) |
| 167 | { |
| 168 | Elf_Sym *sym, *maxsym; |
| 169 | int low, mid, high, nglob; |
| 170 | char *str, *cmp; |
| 171 | |
| 172 | sym = table->sd_symstart; |
| 173 | str = table->sd_strstart - table->sd_usroffset; |
| 174 | nglob = table->sd_nglob; |
| 175 | low = 0; |
| 176 | high = nglob; |
| 177 | |
| 178 | /* |
| 179 | * Start with a binary search of all global symbols in this table. |
| 180 | * Global symbols must have unique names. |
| 181 | */ |
| 182 | while (low < high) { |
| 183 | mid = (low + high) >> 1; |
| 184 | cmp = sym[mid].st_name + str; |
| 185 | if (cmp[0] < name[0] || strcmp(cmp, name) < 0) { |
| 186 | low = mid + 1; |
| 187 | } else { |
| 188 | high = mid; |
| 189 | } |
| 190 | } |
| 191 | KASSERT(low == high); |
| 192 | if (__predict_true(low < nglob && |
| 193 | strcmp(sym[low].st_name + str, name) == 0)) { |
| 194 | KASSERT(ELF_ST_BIND(sym[low].st_info) == STB_GLOBAL); |
| 195 | return &sym[low]; |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | * Perform a linear search of local symbols (rare). Many local |
| 200 | * symbols with the same name can exist so are not included in |
| 201 | * the binary search. |
| 202 | */ |
| 203 | if (type != KSYMS_EXTERN) { |
| 204 | maxsym = sym + table->sd_symsize / sizeof(Elf_Sym); |
| 205 | for (sym += nglob; sym < maxsym; sym++) { |
| 206 | if (strcmp(name, sym->st_name + str) == 0) { |
| 207 | return sym; |
| 208 | } |
| 209 | } |
| 210 | } |
| 211 | return NULL; |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * The "attach" is in reality done in ksyms_init(). |
| 216 | */ |
| 217 | #if NKSYMS > 0 |
| 218 | /* |
| 219 | * ksyms can be loaded even if the kernel has a missing "pseudo-device ksyms" |
| 220 | * statement because ddb and modules require it. Fixing it properly requires |
| 221 | * fixing config to warn about required, but missing preudo-devices. For now, |
| 222 | * if we don't have the pseudo-device we don't need the attach function; this |
| 223 | * is fine, as it does nothing. |
| 224 | */ |
| 225 | void |
| 226 | ksymsattach(int arg) |
| 227 | { |
| 228 | } |
| 229 | #endif |
| 230 | |
| 231 | void |
| 232 | ksyms_init(void) |
| 233 | { |
| 234 | |
| 235 | #ifdef makeoptions_COPY_SYMTAB |
| 236 | if (!ksyms_loaded && |
| 237 | strncmp(db_symtab, SYMTAB_FILLER, sizeof(SYMTAB_FILLER))) { |
| 238 | ksyms_addsyms_elf(db_symtabsize, db_symtab, |
| 239 | db_symtab + db_symtabsize); |
| 240 | } |
| 241 | #endif |
| 242 | |
| 243 | if (!ksyms_initted) { |
| 244 | mutex_init(&ksyms_lock, MUTEX_DEFAULT, IPL_NONE); |
| 245 | ksyms_initted = true; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | * Add a symbol table. |
| 251 | * This is intended for use when the symbol table and its corresponding |
| 252 | * string table are easily available. If they are embedded in an ELF |
| 253 | * image, use addsymtab_elf() instead. |
| 254 | * |
| 255 | * name - Symbol's table name. |
| 256 | * symstart, symsize - Address and size of the symbol table. |
| 257 | * strstart, strsize - Address and size of the string table. |
| 258 | * tab - Symbol table to be updated with this information. |
| 259 | * newstart - Address to which the symbol table has to be copied during |
| 260 | * shrinking. If NULL, it is not moved. |
| 261 | */ |
| 262 | static const char *addsymtab_strstart; |
| 263 | |
| 264 | static int |
| 265 | addsymtab_compar(const void *a, const void *b) |
| 266 | { |
| 267 | const Elf_Sym *sa, *sb; |
| 268 | |
| 269 | sa = a; |
| 270 | sb = b; |
| 271 | |
| 272 | /* |
| 273 | * Split the symbol table into two, with globals at the start |
| 274 | * and locals at the end. |
| 275 | */ |
| 276 | if (ELF_ST_BIND(sa->st_info) != ELF_ST_BIND(sb->st_info)) { |
| 277 | if (ELF_ST_BIND(sa->st_info) == STB_GLOBAL) { |
| 278 | return -1; |
| 279 | } |
| 280 | if (ELF_ST_BIND(sb->st_info) == STB_GLOBAL) { |
| 281 | return 1; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | /* Within each band, sort by name. */ |
| 286 | return strcmp(sa->st_name + addsymtab_strstart, |
| 287 | sb->st_name + addsymtab_strstart); |
| 288 | } |
| 289 | |
| 290 | static void |
| 291 | addsymtab(const char *name, void *symstart, size_t symsize, |
| 292 | void *strstart, size_t strsize, struct ksyms_symtab *tab, |
| 293 | void *newstart, void *ctfstart, size_t ctfsize, uint32_t *nmap) |
| 294 | { |
| 295 | Elf_Sym *sym, *nsym, ts; |
| 296 | int i, j, n, nglob; |
| 297 | char *str; |
| 298 | int nsyms = symsize / sizeof(Elf_Sym); |
| 299 | |
| 300 | /* Sanity check for pre-allocated map table used during startup. */ |
| 301 | if ((nmap == ksyms_nmap) && (nsyms >= KSYMS_MAX_ID)) { |
| 302 | printf("kern_ksyms: ERROR %d > %d, increase KSYMS_MAX_ID\n" , |
| 303 | nsyms, KSYMS_MAX_ID); |
| 304 | |
| 305 | /* truncate for now */ |
| 306 | nsyms = KSYMS_MAX_ID - 1; |
| 307 | } |
| 308 | |
| 309 | tab->sd_symstart = symstart; |
| 310 | tab->sd_symsize = symsize; |
| 311 | tab->sd_strstart = strstart; |
| 312 | tab->sd_strsize = strsize; |
| 313 | tab->sd_name = name; |
| 314 | tab->sd_minsym = UINTPTR_MAX; |
| 315 | tab->sd_maxsym = 0; |
| 316 | tab->sd_usroffset = 0; |
| 317 | tab->sd_gone = false; |
| 318 | tab->sd_ctfstart = ctfstart; |
| 319 | tab->sd_ctfsize = ctfsize; |
| 320 | tab->sd_nmap = nmap; |
| 321 | tab->sd_nmapsize = nsyms; |
| 322 | #ifdef KSYMS_DEBUG |
| 323 | printf("newstart %p sym %p ksyms_symsz %zu str %p strsz %zu send %p\n" , |
| 324 | newstart, symstart, symsize, strstart, strsize, |
| 325 | tab->sd_strstart + tab->sd_strsize); |
| 326 | #endif |
| 327 | |
| 328 | if (nmap) { |
| 329 | memset(nmap, 0, nsyms * sizeof(uint32_t)); |
| 330 | } |
| 331 | |
| 332 | /* Pack symbol table by removing all file name references. */ |
| 333 | sym = tab->sd_symstart; |
| 334 | nsym = (Elf_Sym *)newstart; |
| 335 | str = tab->sd_strstart; |
| 336 | nglob = 0; |
| 337 | for (i = n = 0; i < nsyms; i++) { |
| 338 | |
| 339 | /* This breaks CTF mapping, so don't do it when |
| 340 | * DTrace is enabled |
| 341 | */ |
| 342 | #ifndef KDTRACE_HOOKS |
| 343 | /* |
| 344 | * Remove useless symbols. |
| 345 | * Should actually remove all typeless symbols. |
| 346 | */ |
| 347 | if (sym[i].st_name == 0) |
| 348 | continue; /* Skip nameless entries */ |
| 349 | if (sym[i].st_shndx == SHN_UNDEF) |
| 350 | continue; /* Skip external references */ |
| 351 | if (ELF_ST_TYPE(sym[i].st_info) == STT_FILE) |
| 352 | continue; /* Skip filenames */ |
| 353 | if (ELF_ST_TYPE(sym[i].st_info) == STT_NOTYPE && |
| 354 | sym[i].st_value == 0 && |
| 355 | strcmp(str + sym[i].st_name, "*ABS*" ) == 0) |
| 356 | continue; /* XXX */ |
| 357 | if (ELF_ST_TYPE(sym[i].st_info) == STT_NOTYPE && |
| 358 | strcmp(str + sym[i].st_name, "gcc2_compiled." ) == 0) |
| 359 | continue; /* XXX */ |
| 360 | #endif |
| 361 | |
| 362 | /* Save symbol. Set it as an absolute offset */ |
| 363 | nsym[n] = sym[i]; |
| 364 | |
| 365 | #ifdef KDTRACE_HOOKS |
| 366 | if (nmap != NULL) { |
| 367 | /* |
| 368 | * Save the size, replace it with the symbol id so |
| 369 | * the mapping can be done after the cleanup and sort. |
| 370 | */ |
| 371 | nmap[i] = nsym[n].st_size; |
| 372 | nsym[n].st_size = i + 1; /* zero is reserved */ |
| 373 | } |
| 374 | #endif |
| 375 | |
| 376 | nsym[n].st_shndx = SHBSS; |
| 377 | j = strlen(nsym[n].st_name + str) + 1; |
| 378 | if (j > ksyms_maxlen) |
| 379 | ksyms_maxlen = j; |
| 380 | nglob += (ELF_ST_BIND(nsym[n].st_info) == STB_GLOBAL); |
| 381 | |
| 382 | /* Compute min and max symbols. */ |
| 383 | if (strcmp(str + sym[i].st_name, "*ABS*" ) != 0 |
| 384 | && ELF_ST_TYPE(nsym[n].st_info) != STT_NOTYPE) { |
| 385 | if (nsym[n].st_value < tab->sd_minsym) { |
| 386 | tab->sd_minsym = nsym[n].st_value; |
| 387 | } |
| 388 | if (nsym[n].st_value > tab->sd_maxsym) { |
| 389 | tab->sd_maxsym = nsym[n].st_value; |
| 390 | } |
| 391 | } |
| 392 | n++; |
| 393 | } |
| 394 | |
| 395 | /* Fill the rest of the record, and sort the symbols. */ |
| 396 | tab->sd_symstart = nsym; |
| 397 | tab->sd_symsize = n * sizeof(Elf_Sym); |
| 398 | tab->sd_nglob = nglob; |
| 399 | addsymtab_strstart = str; |
| 400 | if (kheapsort(nsym, n, sizeof(Elf_Sym), addsymtab_compar, &ts) != 0) |
| 401 | panic("addsymtab" ); |
| 402 | |
| 403 | #ifdef KDTRACE_HOOKS |
| 404 | /* |
| 405 | * Build the mapping from original symbol id to new symbol table. |
| 406 | * Deleted symbols will have a zero map, indices will be one based |
| 407 | * instead of zero based. |
| 408 | * Resulting map is sd_nmap[original_index] = new_index + 1 |
| 409 | */ |
| 410 | if (nmap != NULL) { |
| 411 | int new; |
| 412 | for (new = 0; new < n; new++) { |
| 413 | uint32_t orig = nsym[new].st_size - 1; |
| 414 | uint32_t size = nmap[orig]; |
| 415 | |
| 416 | nmap[orig] = new + 1; |
| 417 | |
| 418 | /* restore the size */ |
| 419 | nsym[new].st_size = size; |
| 420 | } |
| 421 | } |
| 422 | #endif |
| 423 | |
| 424 | /* ksymsread() is unlocked, so membar. */ |
| 425 | membar_producer(); |
| 426 | TAILQ_INSERT_TAIL(&ksyms_symtabs, tab, sd_queue); |
| 427 | ksyms_sizes_calc(); |
| 428 | ksyms_loaded = true; |
| 429 | } |
| 430 | |
| 431 | /* |
| 432 | * Setup the kernel symbol table stuff. |
| 433 | */ |
| 434 | void |
| 435 | ksyms_addsyms_elf(int symsize, void *start, void *end) |
| 436 | { |
| 437 | int i, j; |
| 438 | Elf_Shdr *shdr; |
| 439 | char *symstart = NULL, *strstart = NULL; |
| 440 | size_t strsize = 0; |
| 441 | Elf_Ehdr *ehdr; |
| 442 | char *ctfstart = NULL; |
| 443 | size_t ctfsize = 0; |
| 444 | |
| 445 | if (symsize <= 0) { |
| 446 | printf("[ Kernel symbol table missing! ]\n" ); |
| 447 | return; |
| 448 | } |
| 449 | |
| 450 | /* Sanity check */ |
| 451 | if (ALIGNED_POINTER(start, long) == 0) { |
| 452 | printf("[ Kernel symbol table has bad start address %p ]\n" , |
| 453 | start); |
| 454 | return; |
| 455 | } |
| 456 | |
| 457 | ehdr = (Elf_Ehdr *)start; |
| 458 | |
| 459 | /* check if this is a valid ELF header */ |
| 460 | /* No reason to verify arch type, the kernel is actually running! */ |
| 461 | if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) || |
| 462 | ehdr->e_ident[EI_CLASS] != ELFCLASS || |
| 463 | ehdr->e_version > 1) { |
| 464 | printf("[ Kernel symbol table invalid! ]\n" ); |
| 465 | return; /* nothing to do */ |
| 466 | } |
| 467 | |
| 468 | /* Loaded header will be scratched in addsymtab */ |
| 469 | ksyms_hdr_init(start); |
| 470 | |
| 471 | /* Find the symbol table and the corresponding string table. */ |
| 472 | shdr = (Elf_Shdr *)((uint8_t *)start + ehdr->e_shoff); |
| 473 | for (i = 1; i < ehdr->e_shnum; i++) { |
| 474 | if (shdr[i].sh_type != SHT_SYMTAB) |
| 475 | continue; |
| 476 | if (shdr[i].sh_offset == 0) |
| 477 | continue; |
| 478 | symstart = (uint8_t *)start + shdr[i].sh_offset; |
| 479 | symsize = shdr[i].sh_size; |
| 480 | j = shdr[i].sh_link; |
| 481 | if (shdr[j].sh_offset == 0) |
| 482 | continue; /* Can this happen? */ |
| 483 | strstart = (uint8_t *)start + shdr[j].sh_offset; |
| 484 | strsize = shdr[j].sh_size; |
| 485 | break; |
| 486 | } |
| 487 | |
| 488 | #ifdef KDTRACE_HOOKS |
| 489 | /* Find the CTF section */ |
| 490 | shdr = (Elf_Shdr *)((uint8_t *)start + ehdr->e_shoff); |
| 491 | if (ehdr->e_shstrndx != 0) { |
| 492 | char *shstr = (uint8_t *)start + |
| 493 | shdr[ehdr->e_shstrndx].sh_offset; |
| 494 | for (i = 1; i < ehdr->e_shnum; i++) { |
| 495 | #ifdef DEBUG |
| 496 | printf("ksyms: checking %s\n" , &shstr[shdr[i].sh_name]); |
| 497 | #endif |
| 498 | if (shdr[i].sh_type != SHT_PROGBITS) |
| 499 | continue; |
| 500 | if (strncmp(".SUNW_ctf" , &shstr[shdr[i].sh_name], 10) |
| 501 | != 0) |
| 502 | continue; |
| 503 | ctfstart = (uint8_t *)start + shdr[i].sh_offset; |
| 504 | ctfsize = shdr[i].sh_size; |
| 505 | ksyms_ctfsz = ctfsize; |
| 506 | #ifdef DEBUG |
| 507 | aprint_normal("Found CTF at %p, size 0x%zx\n" , |
| 508 | ctfstart, ctfsize); |
| 509 | #endif |
| 510 | break; |
| 511 | } |
| 512 | #ifdef DEBUG |
| 513 | } else { |
| 514 | printf("ksyms: e_shstrndx == 0\n" ); |
| 515 | #endif |
| 516 | } |
| 517 | #endif |
| 518 | |
| 519 | if (!ksyms_verify(symstart, strstart)) |
| 520 | return; |
| 521 | |
| 522 | addsymtab("netbsd" , symstart, symsize, strstart, strsize, |
| 523 | &kernel_symtab, symstart, ctfstart, ctfsize, ksyms_nmap); |
| 524 | |
| 525 | #ifdef DEBUG |
| 526 | aprint_normal("Loaded initial symtab at %p, strtab at %p, # entries %ld\n" , |
| 527 | kernel_symtab.sd_symstart, kernel_symtab.sd_strstart, |
| 528 | (long)kernel_symtab.sd_symsize/sizeof(Elf_Sym)); |
| 529 | #endif |
| 530 | } |
| 531 | |
| 532 | /* |
| 533 | * Setup the kernel symbol table stuff. |
| 534 | * Use this when the address of the symbol and string tables are known; |
| 535 | * otherwise use ksyms_init with an ELF image. |
| 536 | * We need to pass a minimal ELF header which will later be completed by |
| 537 | * ksyms_hdr_init and handed off to userland through /dev/ksyms. We use |
| 538 | * a void *rather than a pointer to avoid exposing the Elf_Ehdr type. |
| 539 | */ |
| 540 | void |
| 541 | ksyms_addsyms_explicit(void *ehdr, void *symstart, size_t symsize, |
| 542 | void *strstart, size_t strsize) |
| 543 | { |
| 544 | if (!ksyms_verify(symstart, strstart)) |
| 545 | return; |
| 546 | |
| 547 | ksyms_hdr_init(ehdr); |
| 548 | addsymtab("netbsd" , symstart, symsize, strstart, strsize, |
| 549 | &kernel_symtab, symstart, NULL, 0, ksyms_nmap); |
| 550 | } |
| 551 | |
| 552 | /* |
| 553 | * Get the value associated with a symbol. |
| 554 | * "mod" is the module name, or null if any module. |
| 555 | * "sym" is the symbol name. |
| 556 | * "val" is a pointer to the corresponding value, if call succeeded. |
| 557 | * Returns 0 if success or ENOENT if no such entry. |
| 558 | * |
| 559 | * Call with ksyms_lock, unless known that the symbol table can't change. |
| 560 | */ |
| 561 | int |
| 562 | ksyms_getval_unlocked(const char *mod, const char *sym, unsigned long *val, |
| 563 | int type) |
| 564 | { |
| 565 | struct ksyms_symtab *st; |
| 566 | Elf_Sym *es; |
| 567 | |
| 568 | #ifdef KSYMS_DEBUG |
| 569 | if (ksyms_debug & FOLLOW_CALLS) |
| 570 | printf("ksyms_getval_unlocked: mod %s sym %s valp %p\n" , |
| 571 | mod, sym, val); |
| 572 | #endif |
| 573 | |
| 574 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 575 | if (__predict_false(st->sd_gone)) |
| 576 | continue; |
| 577 | if (mod != NULL && strcmp(st->sd_name, mod)) |
| 578 | continue; |
| 579 | if ((es = findsym(sym, st, type)) != NULL) { |
| 580 | *val = es->st_value; |
| 581 | return 0; |
| 582 | } |
| 583 | } |
| 584 | return ENOENT; |
| 585 | } |
| 586 | |
| 587 | int |
| 588 | ksyms_getval(const char *mod, const char *sym, unsigned long *val, int type) |
| 589 | { |
| 590 | int rc; |
| 591 | |
| 592 | if (!ksyms_loaded) |
| 593 | return ENOENT; |
| 594 | |
| 595 | mutex_enter(&ksyms_lock); |
| 596 | rc = ksyms_getval_unlocked(mod, sym, val, type); |
| 597 | mutex_exit(&ksyms_lock); |
| 598 | return rc; |
| 599 | } |
| 600 | |
| 601 | struct ksyms_symtab * |
| 602 | ksyms_get_mod(const char *mod) |
| 603 | { |
| 604 | struct ksyms_symtab *st; |
| 605 | |
| 606 | mutex_enter(&ksyms_lock); |
| 607 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 608 | if (__predict_false(st->sd_gone)) |
| 609 | continue; |
| 610 | if (mod != NULL && strcmp(st->sd_name, mod)) |
| 611 | continue; |
| 612 | break; |
| 613 | } |
| 614 | mutex_exit(&ksyms_lock); |
| 615 | |
| 616 | return st; |
| 617 | } |
| 618 | |
| 619 | |
| 620 | /* |
| 621 | * ksyms_mod_foreach() |
| 622 | * |
| 623 | * Iterate over the symbol table of the specified module, calling the callback |
| 624 | * handler for each symbol. Stop iterating if the handler return is non-zero. |
| 625 | * |
| 626 | */ |
| 627 | |
| 628 | int |
| 629 | ksyms_mod_foreach(const char *mod, ksyms_callback_t callback, void *opaque) |
| 630 | { |
| 631 | struct ksyms_symtab *st; |
| 632 | Elf_Sym *sym, *maxsym; |
| 633 | char *str; |
| 634 | int symindx; |
| 635 | |
| 636 | if (!ksyms_loaded) |
| 637 | return ENOENT; |
| 638 | |
| 639 | mutex_enter(&ksyms_lock); |
| 640 | |
| 641 | /* find the module */ |
| 642 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 643 | if (__predict_false(st->sd_gone)) |
| 644 | continue; |
| 645 | if (mod != NULL && strcmp(st->sd_name, mod)) |
| 646 | continue; |
| 647 | |
| 648 | sym = st->sd_symstart; |
| 649 | str = st->sd_strstart - st->sd_usroffset; |
| 650 | |
| 651 | /* now iterate through the symbols */ |
| 652 | maxsym = sym + st->sd_symsize / sizeof(Elf_Sym); |
| 653 | for (symindx = 0; sym < maxsym; sym++, symindx++) { |
| 654 | if (callback(str + sym->st_name, symindx, |
| 655 | (void *)sym->st_value, |
| 656 | sym->st_size, |
| 657 | sym->st_info, |
| 658 | opaque) != 0) { |
| 659 | break; |
| 660 | } |
| 661 | } |
| 662 | } |
| 663 | mutex_exit(&ksyms_lock); |
| 664 | |
| 665 | return 0; |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Get "mod" and "symbol" associated with an address. |
| 670 | * Returns 0 if success or ENOENT if no such entry. |
| 671 | * |
| 672 | * Call with ksyms_lock, unless known that the symbol table can't change. |
| 673 | */ |
| 674 | int |
| 675 | ksyms_getname(const char **mod, const char **sym, vaddr_t v, int f) |
| 676 | { |
| 677 | struct ksyms_symtab *st; |
| 678 | Elf_Sym *les, *es = NULL; |
| 679 | vaddr_t laddr = 0; |
| 680 | const char *lmod = NULL; |
| 681 | char *stable = NULL; |
| 682 | int type, i, sz; |
| 683 | |
| 684 | if (!ksyms_loaded) |
| 685 | return ENOENT; |
| 686 | |
| 687 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 688 | if (st->sd_gone) |
| 689 | continue; |
| 690 | if (v < st->sd_minsym || v > st->sd_maxsym) |
| 691 | continue; |
| 692 | sz = st->sd_symsize/sizeof(Elf_Sym); |
| 693 | for (i = 0; i < sz; i++) { |
| 694 | les = st->sd_symstart + i; |
| 695 | type = ELF_ST_TYPE(les->st_info); |
| 696 | |
| 697 | if ((f & KSYMS_PROC) && (type != STT_FUNC)) |
| 698 | continue; |
| 699 | |
| 700 | if (type == STT_NOTYPE) |
| 701 | continue; |
| 702 | |
| 703 | if (((f & KSYMS_ANY) == 0) && |
| 704 | (type != STT_FUNC) && (type != STT_OBJECT)) |
| 705 | continue; |
| 706 | |
| 707 | if ((les->st_value <= v) && (les->st_value > laddr)) { |
| 708 | laddr = les->st_value; |
| 709 | es = les; |
| 710 | lmod = st->sd_name; |
| 711 | stable = st->sd_strstart - st->sd_usroffset; |
| 712 | } |
| 713 | } |
| 714 | } |
| 715 | if (es == NULL) |
| 716 | return ENOENT; |
| 717 | if ((f & KSYMS_EXACT) && (v != es->st_value)) |
| 718 | return ENOENT; |
| 719 | if (mod) |
| 720 | *mod = lmod; |
| 721 | if (sym) |
| 722 | *sym = stable + es->st_name; |
| 723 | return 0; |
| 724 | } |
| 725 | |
| 726 | /* |
| 727 | * Add a symbol table from a loadable module. |
| 728 | */ |
| 729 | void |
| 730 | ksyms_modload(const char *name, void *symstart, vsize_t symsize, |
| 731 | char *strstart, vsize_t strsize) |
| 732 | { |
| 733 | struct ksyms_symtab *st; |
| 734 | |
| 735 | st = kmem_zalloc(sizeof(*st), KM_SLEEP); |
| 736 | mutex_enter(&ksyms_lock); |
| 737 | addsymtab(name, symstart, symsize, strstart, strsize, st, symstart, |
| 738 | NULL, 0, NULL); |
| 739 | mutex_exit(&ksyms_lock); |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Remove a symbol table from a loadable module. |
| 744 | */ |
| 745 | void |
| 746 | ksyms_modunload(const char *name) |
| 747 | { |
| 748 | struct ksyms_symtab *st; |
| 749 | |
| 750 | mutex_enter(&ksyms_lock); |
| 751 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 752 | if (st->sd_gone) |
| 753 | continue; |
| 754 | if (strcmp(name, st->sd_name) != 0) |
| 755 | continue; |
| 756 | st->sd_gone = true; |
| 757 | if (!ksyms_isopen) { |
| 758 | TAILQ_REMOVE(&ksyms_symtabs, st, sd_queue); |
| 759 | ksyms_sizes_calc(); |
| 760 | kmem_free(st, sizeof(*st)); |
| 761 | } |
| 762 | break; |
| 763 | } |
| 764 | mutex_exit(&ksyms_lock); |
| 765 | KASSERT(st != NULL); |
| 766 | } |
| 767 | |
| 768 | #ifdef DDB |
| 769 | /* |
| 770 | * Keep sifting stuff here, to avoid export of ksyms internals. |
| 771 | * |
| 772 | * Systems is expected to be quiescent, so no locking done. |
| 773 | */ |
| 774 | int |
| 775 | ksyms_sift(char *mod, char *sym, int mode) |
| 776 | { |
| 777 | struct ksyms_symtab *st; |
| 778 | char *sb; |
| 779 | int i, sz; |
| 780 | |
| 781 | if (!ksyms_loaded) |
| 782 | return ENOENT; |
| 783 | |
| 784 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 785 | if (st->sd_gone) |
| 786 | continue; |
| 787 | if (mod && strcmp(mod, st->sd_name)) |
| 788 | continue; |
| 789 | sb = st->sd_strstart - st->sd_usroffset; |
| 790 | |
| 791 | sz = st->sd_symsize/sizeof(Elf_Sym); |
| 792 | for (i = 0; i < sz; i++) { |
| 793 | Elf_Sym *les = st->sd_symstart + i; |
| 794 | char c; |
| 795 | |
| 796 | if (strstr(sb + les->st_name, sym) == NULL) |
| 797 | continue; |
| 798 | |
| 799 | if (mode == 'F') { |
| 800 | switch (ELF_ST_TYPE(les->st_info)) { |
| 801 | case STT_OBJECT: |
| 802 | c = '+'; |
| 803 | break; |
| 804 | case STT_FUNC: |
| 805 | c = '*'; |
| 806 | break; |
| 807 | case STT_SECTION: |
| 808 | c = '&'; |
| 809 | break; |
| 810 | case STT_FILE: |
| 811 | c = '/'; |
| 812 | break; |
| 813 | default: |
| 814 | c = ' '; |
| 815 | break; |
| 816 | } |
| 817 | db_printf("%s%c " , sb + les->st_name, c); |
| 818 | } else |
| 819 | db_printf("%s " , sb + les->st_name); |
| 820 | } |
| 821 | } |
| 822 | return ENOENT; |
| 823 | } |
| 824 | #endif /* DDB */ |
| 825 | |
| 826 | /* |
| 827 | * In case we exposing the symbol table to the userland using the pseudo- |
| 828 | * device /dev/ksyms, it is easier to provide all the tables as one. |
| 829 | * However, it means we have to change all the st_name fields for the |
| 830 | * symbols so they match the ELF image that the userland will read |
| 831 | * through the device. |
| 832 | * |
| 833 | * The actual (correct) value of st_name is preserved through a global |
| 834 | * offset stored in the symbol table structure. |
| 835 | * |
| 836 | * Call with ksyms_lock held. |
| 837 | */ |
| 838 | static void |
| 839 | ksyms_sizes_calc(void) |
| 840 | { |
| 841 | struct ksyms_symtab *st; |
| 842 | int i, delta; |
| 843 | |
| 844 | ksyms_symsz = ksyms_strsz = 0; |
| 845 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 846 | delta = ksyms_strsz - st->sd_usroffset; |
| 847 | if (delta != 0) { |
| 848 | for (i = 0; i < st->sd_symsize/sizeof(Elf_Sym); i++) |
| 849 | st->sd_symstart[i].st_name += delta; |
| 850 | st->sd_usroffset = ksyms_strsz; |
| 851 | } |
| 852 | ksyms_symsz += st->sd_symsize; |
| 853 | ksyms_strsz += st->sd_strsize; |
| 854 | } |
| 855 | } |
| 856 | |
| 857 | static void |
| 858 | ksyms_fill_note(void) |
| 859 | { |
| 860 | int32_t *note = ksyms_hdr.kh_note; |
| 861 | note[0] = ELF_NOTE_NETBSD_NAMESZ; |
| 862 | note[1] = ELF_NOTE_NETBSD_DESCSZ; |
| 863 | note[2] = ELF_NOTE_TYPE_NETBSD_TAG; |
| 864 | memcpy(¬e[3], "NetBSD\0" , 8); |
| 865 | note[5] = __NetBSD_Version__; |
| 866 | } |
| 867 | |
| 868 | static void |
| 869 | ksyms_hdr_init(const void *hdraddr) |
| 870 | { |
| 871 | /* Copy the loaded elf exec header */ |
| 872 | memcpy(&ksyms_hdr.kh_ehdr, hdraddr, sizeof(Elf_Ehdr)); |
| 873 | |
| 874 | /* Set correct program/section header sizes, offsets and numbers */ |
| 875 | ksyms_hdr.kh_ehdr.e_phoff = offsetof(struct ksyms_hdr, kh_phdr[0]); |
| 876 | ksyms_hdr.kh_ehdr.e_phentsize = sizeof(Elf_Phdr); |
| 877 | ksyms_hdr.kh_ehdr.e_phnum = NPRGHDR; |
| 878 | ksyms_hdr.kh_ehdr.e_shoff = offsetof(struct ksyms_hdr, kh_shdr[0]); |
| 879 | ksyms_hdr.kh_ehdr.e_shentsize = sizeof(Elf_Shdr); |
| 880 | ksyms_hdr.kh_ehdr.e_shnum = NSECHDR; |
| 881 | ksyms_hdr.kh_ehdr.e_shstrndx = SHSTRTAB; |
| 882 | |
| 883 | /* Text/data - fake */ |
| 884 | ksyms_hdr.kh_phdr[0].p_type = PT_LOAD; |
| 885 | ksyms_hdr.kh_phdr[0].p_memsz = (unsigned long)-1L; |
| 886 | ksyms_hdr.kh_phdr[0].p_flags = PF_R | PF_X | PF_W; |
| 887 | |
| 888 | #define SHTCOPY(name) strlcpy(&ksyms_hdr.kh_strtab[offs], (name), \ |
| 889 | sizeof(ksyms_hdr.kh_strtab) - offs), offs += sizeof(name) |
| 890 | |
| 891 | uint32_t offs = 1; |
| 892 | /* First section header ".note.netbsd.ident" */ |
| 893 | ksyms_hdr.kh_shdr[SHNOTE].sh_name = offs; |
| 894 | ksyms_hdr.kh_shdr[SHNOTE].sh_type = SHT_NOTE; |
| 895 | ksyms_hdr.kh_shdr[SHNOTE].sh_offset = |
| 896 | offsetof(struct ksyms_hdr, kh_note[0]); |
| 897 | ksyms_hdr.kh_shdr[SHNOTE].sh_size = sizeof(ksyms_hdr.kh_note); |
| 898 | ksyms_hdr.kh_shdr[SHNOTE].sh_addralign = sizeof(int); |
| 899 | SHTCOPY(".note.netbsd.ident" ); |
| 900 | ksyms_fill_note(); |
| 901 | |
| 902 | /* Second section header; ".symtab" */ |
| 903 | ksyms_hdr.kh_shdr[SYMTAB].sh_name = offs; |
| 904 | ksyms_hdr.kh_shdr[SYMTAB].sh_type = SHT_SYMTAB; |
| 905 | ksyms_hdr.kh_shdr[SYMTAB].sh_offset = sizeof(struct ksyms_hdr); |
| 906 | /* ksyms_hdr.kh_shdr[SYMTAB].sh_size = filled in at open */ |
| 907 | ksyms_hdr.kh_shdr[SYMTAB].sh_link = STRTAB; /* Corresponding strtab */ |
| 908 | ksyms_hdr.kh_shdr[SYMTAB].sh_addralign = sizeof(long); |
| 909 | ksyms_hdr.kh_shdr[SYMTAB].sh_entsize = sizeof(Elf_Sym); |
| 910 | SHTCOPY(".symtab" ); |
| 911 | |
| 912 | /* Third section header; ".strtab" */ |
| 913 | ksyms_hdr.kh_shdr[STRTAB].sh_name = offs; |
| 914 | ksyms_hdr.kh_shdr[STRTAB].sh_type = SHT_STRTAB; |
| 915 | /* ksyms_hdr.kh_shdr[STRTAB].sh_offset = filled in at open */ |
| 916 | /* ksyms_hdr.kh_shdr[STRTAB].sh_size = filled in at open */ |
| 917 | ksyms_hdr.kh_shdr[STRTAB].sh_addralign = sizeof(char); |
| 918 | SHTCOPY(".strtab" ); |
| 919 | |
| 920 | /* Fourth section, ".shstrtab" */ |
| 921 | ksyms_hdr.kh_shdr[SHSTRTAB].sh_name = offs; |
| 922 | ksyms_hdr.kh_shdr[SHSTRTAB].sh_type = SHT_STRTAB; |
| 923 | ksyms_hdr.kh_shdr[SHSTRTAB].sh_offset = |
| 924 | offsetof(struct ksyms_hdr, kh_strtab); |
| 925 | ksyms_hdr.kh_shdr[SHSTRTAB].sh_size = SHSTRSIZ; |
| 926 | ksyms_hdr.kh_shdr[SHSTRTAB].sh_addralign = sizeof(char); |
| 927 | SHTCOPY(".shstrtab" ); |
| 928 | |
| 929 | /* Fifth section, ".bss". All symbols reside here. */ |
| 930 | ksyms_hdr.kh_shdr[SHBSS].sh_name = offs; |
| 931 | ksyms_hdr.kh_shdr[SHBSS].sh_type = SHT_NOBITS; |
| 932 | ksyms_hdr.kh_shdr[SHBSS].sh_offset = 0; |
| 933 | ksyms_hdr.kh_shdr[SHBSS].sh_size = (unsigned long)-1L; |
| 934 | ksyms_hdr.kh_shdr[SHBSS].sh_addralign = PAGE_SIZE; |
| 935 | ksyms_hdr.kh_shdr[SHBSS].sh_flags = SHF_ALLOC | SHF_EXECINSTR; |
| 936 | SHTCOPY(".bss" ); |
| 937 | |
| 938 | /* Sixth section header; ".SUNW_ctf" */ |
| 939 | ksyms_hdr.kh_shdr[SHCTF].sh_name = offs; |
| 940 | ksyms_hdr.kh_shdr[SHCTF].sh_type = SHT_PROGBITS; |
| 941 | /* ksyms_hdr.kh_shdr[SHCTF].sh_offset = filled in at open */ |
| 942 | /* ksyms_hdr.kh_shdr[SHCTF].sh_size = filled in at open */ |
| 943 | ksyms_hdr.kh_shdr[SHCTF].sh_link = SYMTAB; /* Corresponding symtab */ |
| 944 | ksyms_hdr.kh_shdr[SHCTF].sh_addralign = sizeof(char); |
| 945 | SHTCOPY(".SUNW_ctf" ); |
| 946 | } |
| 947 | |
| 948 | static int |
| 949 | ksymsopen(dev_t dev, int oflags, int devtype, struct lwp *l) |
| 950 | { |
| 951 | if (minor(dev) != 0 || !ksyms_loaded) |
| 952 | return ENXIO; |
| 953 | |
| 954 | /* |
| 955 | * Create a "snapshot" of the kernel symbol table. Setting |
| 956 | * ksyms_isopen will prevent symbol tables from being freed. |
| 957 | */ |
| 958 | mutex_enter(&ksyms_lock); |
| 959 | ksyms_hdr.kh_shdr[SYMTAB].sh_size = ksyms_symsz; |
| 960 | ksyms_hdr.kh_shdr[SYMTAB].sh_info = ksyms_symsz / sizeof(Elf_Sym); |
| 961 | ksyms_hdr.kh_shdr[STRTAB].sh_offset = ksyms_symsz + |
| 962 | ksyms_hdr.kh_shdr[SYMTAB].sh_offset; |
| 963 | ksyms_hdr.kh_shdr[STRTAB].sh_size = ksyms_strsz; |
| 964 | ksyms_hdr.kh_shdr[SHCTF].sh_offset = ksyms_strsz + |
| 965 | ksyms_hdr.kh_shdr[STRTAB].sh_offset; |
| 966 | ksyms_hdr.kh_shdr[SHCTF].sh_size = ksyms_ctfsz; |
| 967 | ksyms_isopen = true; |
| 968 | mutex_exit(&ksyms_lock); |
| 969 | |
| 970 | return 0; |
| 971 | } |
| 972 | |
| 973 | static int |
| 974 | ksymsclose(dev_t dev, int oflags, int devtype, struct lwp *l) |
| 975 | { |
| 976 | struct ksyms_symtab *st, *next; |
| 977 | bool resize; |
| 978 | |
| 979 | /* Discard references to symbol tables. */ |
| 980 | mutex_enter(&ksyms_lock); |
| 981 | ksyms_isopen = false; |
| 982 | resize = false; |
| 983 | for (st = TAILQ_FIRST(&ksyms_symtabs); st != NULL; st = next) { |
| 984 | next = TAILQ_NEXT(st, sd_queue); |
| 985 | if (st->sd_gone) { |
| 986 | TAILQ_REMOVE(&ksyms_symtabs, st, sd_queue); |
| 987 | kmem_free(st, sizeof(*st)); |
| 988 | resize = true; |
| 989 | } |
| 990 | } |
| 991 | if (resize) |
| 992 | ksyms_sizes_calc(); |
| 993 | mutex_exit(&ksyms_lock); |
| 994 | |
| 995 | return 0; |
| 996 | } |
| 997 | |
| 998 | static int |
| 999 | ksymsread(dev_t dev, struct uio *uio, int ioflag) |
| 1000 | { |
| 1001 | struct ksyms_symtab *st; |
| 1002 | size_t filepos, inpos, off; |
| 1003 | int error; |
| 1004 | |
| 1005 | /* |
| 1006 | * First: Copy out the ELF header. XXX Lose if ksymsopen() |
| 1007 | * occurs during read of the header. |
| 1008 | */ |
| 1009 | off = uio->uio_offset; |
| 1010 | if (off < sizeof(struct ksyms_hdr)) { |
| 1011 | error = uiomove((char *)&ksyms_hdr + off, |
| 1012 | sizeof(struct ksyms_hdr) - off, uio); |
| 1013 | if (error != 0) |
| 1014 | return error; |
| 1015 | } |
| 1016 | |
| 1017 | /* |
| 1018 | * Copy out the symbol table. |
| 1019 | */ |
| 1020 | filepos = sizeof(struct ksyms_hdr); |
| 1021 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 1022 | if (uio->uio_resid == 0) |
| 1023 | return 0; |
| 1024 | if (uio->uio_offset <= st->sd_symsize + filepos) { |
| 1025 | inpos = uio->uio_offset - filepos; |
| 1026 | error = uiomove((char *)st->sd_symstart + inpos, |
| 1027 | st->sd_symsize - inpos, uio); |
| 1028 | if (error != 0) |
| 1029 | return error; |
| 1030 | } |
| 1031 | filepos += st->sd_symsize; |
| 1032 | } |
| 1033 | |
| 1034 | /* |
| 1035 | * Copy out the string table |
| 1036 | */ |
| 1037 | KASSERT(filepos == sizeof(struct ksyms_hdr) + |
| 1038 | ksyms_hdr.kh_shdr[SYMTAB].sh_size); |
| 1039 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 1040 | if (uio->uio_resid == 0) |
| 1041 | return 0; |
| 1042 | if (uio->uio_offset <= st->sd_strsize + filepos) { |
| 1043 | inpos = uio->uio_offset - filepos; |
| 1044 | error = uiomove((char *)st->sd_strstart + inpos, |
| 1045 | st->sd_strsize - inpos, uio); |
| 1046 | if (error != 0) |
| 1047 | return error; |
| 1048 | } |
| 1049 | filepos += st->sd_strsize; |
| 1050 | } |
| 1051 | |
| 1052 | /* |
| 1053 | * Copy out the CTF table. |
| 1054 | */ |
| 1055 | st = TAILQ_FIRST(&ksyms_symtabs); |
| 1056 | if (st->sd_ctfstart != NULL) { |
| 1057 | if (uio->uio_resid == 0) |
| 1058 | return 0; |
| 1059 | if (uio->uio_offset <= st->sd_ctfsize + filepos) { |
| 1060 | inpos = uio->uio_offset - filepos; |
| 1061 | error = uiomove((char *)st->sd_ctfstart + inpos, |
| 1062 | st->sd_ctfsize - inpos, uio); |
| 1063 | if (error != 0) |
| 1064 | return error; |
| 1065 | } |
| 1066 | filepos += st->sd_ctfsize; |
| 1067 | } |
| 1068 | |
| 1069 | return 0; |
| 1070 | } |
| 1071 | |
| 1072 | static int |
| 1073 | ksymswrite(dev_t dev, struct uio *uio, int ioflag) |
| 1074 | { |
| 1075 | return EROFS; |
| 1076 | } |
| 1077 | |
| 1078 | __CTASSERT(offsetof(struct ksyms_ogsymbol, kg_name) == offsetof(struct ksyms_gsymbol, kg_name)); |
| 1079 | __CTASSERT(offsetof(struct ksyms_gvalue, kv_name) == offsetof(struct ksyms_gsymbol, kg_name)); |
| 1080 | |
| 1081 | static int |
| 1082 | ksymsioctl(dev_t dev, u_long cmd, void *data, int fflag, struct lwp *l) |
| 1083 | { |
| 1084 | struct ksyms_ogsymbol *okg = (struct ksyms_ogsymbol *)data; |
| 1085 | struct ksyms_gsymbol *kg = (struct ksyms_gsymbol *)data; |
| 1086 | struct ksyms_gvalue *kv = (struct ksyms_gvalue *)data; |
| 1087 | struct ksyms_symtab *st; |
| 1088 | Elf_Sym *sym = NULL, copy; |
| 1089 | unsigned long val; |
| 1090 | int error = 0; |
| 1091 | char *str = NULL; |
| 1092 | int len; |
| 1093 | |
| 1094 | /* Read ksyms_maxlen only once while not holding the lock. */ |
| 1095 | len = ksyms_maxlen; |
| 1096 | |
| 1097 | if (cmd == OKIOCGVALUE || cmd == OKIOCGSYMBOL || |
| 1098 | cmd == KIOCGVALUE || cmd == KIOCGSYMBOL) { |
| 1099 | str = kmem_alloc(len, KM_SLEEP); |
| 1100 | if ((error = copyinstr(kg->kg_name, str, len, NULL)) != 0) { |
| 1101 | kmem_free(str, len); |
| 1102 | return error; |
| 1103 | } |
| 1104 | } |
| 1105 | |
| 1106 | switch (cmd) { |
| 1107 | case OKIOCGVALUE: |
| 1108 | /* |
| 1109 | * Use the in-kernel symbol lookup code for fast |
| 1110 | * retreival of a value. |
| 1111 | */ |
| 1112 | error = ksyms_getval(NULL, str, &val, KSYMS_EXTERN); |
| 1113 | if (error == 0) |
| 1114 | error = copyout(&val, okg->kg_value, sizeof(long)); |
| 1115 | kmem_free(str, len); |
| 1116 | break; |
| 1117 | |
| 1118 | case OKIOCGSYMBOL: |
| 1119 | /* |
| 1120 | * Use the in-kernel symbol lookup code for fast |
| 1121 | * retreival of a symbol. |
| 1122 | */ |
| 1123 | mutex_enter(&ksyms_lock); |
| 1124 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 1125 | if (st->sd_gone) |
| 1126 | continue; |
| 1127 | if ((sym = findsym(str, st, KSYMS_ANY)) == NULL) |
| 1128 | continue; |
| 1129 | #ifdef notdef |
| 1130 | /* Skip if bad binding */ |
| 1131 | if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL) { |
| 1132 | sym = NULL; |
| 1133 | continue; |
| 1134 | } |
| 1135 | #endif |
| 1136 | break; |
| 1137 | } |
| 1138 | if (sym != NULL) { |
| 1139 | memcpy(©, sym, sizeof(copy)); |
| 1140 | mutex_exit(&ksyms_lock); |
| 1141 | error = copyout(©, okg->kg_sym, sizeof(Elf_Sym)); |
| 1142 | } else { |
| 1143 | mutex_exit(&ksyms_lock); |
| 1144 | error = ENOENT; |
| 1145 | } |
| 1146 | kmem_free(str, len); |
| 1147 | break; |
| 1148 | |
| 1149 | case KIOCGVALUE: |
| 1150 | /* |
| 1151 | * Use the in-kernel symbol lookup code for fast |
| 1152 | * retreival of a value. |
| 1153 | */ |
| 1154 | error = ksyms_getval(NULL, str, &val, KSYMS_EXTERN); |
| 1155 | if (error == 0) |
| 1156 | kv->kv_value = val; |
| 1157 | kmem_free(str, len); |
| 1158 | break; |
| 1159 | |
| 1160 | case KIOCGSYMBOL: |
| 1161 | /* |
| 1162 | * Use the in-kernel symbol lookup code for fast |
| 1163 | * retreival of a symbol. |
| 1164 | */ |
| 1165 | mutex_enter(&ksyms_lock); |
| 1166 | TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) { |
| 1167 | if (st->sd_gone) |
| 1168 | continue; |
| 1169 | if ((sym = findsym(str, st, KSYMS_ANY)) == NULL) |
| 1170 | continue; |
| 1171 | #ifdef notdef |
| 1172 | /* Skip if bad binding */ |
| 1173 | if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL) { |
| 1174 | sym = NULL; |
| 1175 | continue; |
| 1176 | } |
| 1177 | #endif |
| 1178 | break; |
| 1179 | } |
| 1180 | if (sym != NULL) { |
| 1181 | kg->kg_sym = *sym; |
| 1182 | } else { |
| 1183 | error = ENOENT; |
| 1184 | } |
| 1185 | mutex_exit(&ksyms_lock); |
| 1186 | kmem_free(str, len); |
| 1187 | break; |
| 1188 | |
| 1189 | case KIOCGSIZE: |
| 1190 | /* |
| 1191 | * Get total size of symbol table. |
| 1192 | */ |
| 1193 | mutex_enter(&ksyms_lock); |
| 1194 | *(int *)data = ksyms_strsz + ksyms_symsz + |
| 1195 | sizeof(struct ksyms_hdr); |
| 1196 | mutex_exit(&ksyms_lock); |
| 1197 | break; |
| 1198 | |
| 1199 | default: |
| 1200 | error = ENOTTY; |
| 1201 | break; |
| 1202 | } |
| 1203 | |
| 1204 | return error; |
| 1205 | } |
| 1206 | |
| 1207 | const struct cdevsw ksyms_cdevsw = { |
| 1208 | .d_open = ksymsopen, |
| 1209 | .d_close = ksymsclose, |
| 1210 | .d_read = ksymsread, |
| 1211 | .d_write = ksymswrite, |
| 1212 | .d_ioctl = ksymsioctl, |
| 1213 | .d_stop = nullstop, |
| 1214 | .d_tty = notty, |
| 1215 | .d_poll = nopoll, |
| 1216 | .d_mmap = nommap, |
| 1217 | .d_kqfilter = nullkqfilter, |
| 1218 | .d_discard = nodiscard, |
| 1219 | .d_flag = D_OTHER | D_MPSAFE |
| 1220 | }; |
| 1221 | |