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| 1 #define _GNU_SOURCE |
| 2 #include <stdio.h> |
| 3 #include <stdlib.h> |
| 4 #include <stdarg.h> |
| 5 #include <stddef.h> |
| 6 #include <string.h> |
| 7 #include <unistd.h> |
| 8 #include <stdint.h> |
| 9 #include <elf.h> |
| 10 #include <sys/mman.h> |
| 11 #include <limits.h> |
| 12 #include <fcntl.h> |
| 13 #include <sys/stat.h> |
| 14 #include <errno.h> |
| 15 #include <link.h> |
| 16 #include <setjmp.h> |
| 17 #include <pthread.h> |
| 18 #include <ctype.h> |
| 19 #include <dlfcn.h> |
| 20 #include "pthread_impl.h" |
| 21 #include "libc.h" |
| 22 #include "dynlink.h" |
| 23 |
| 24 static void error(const char *, ...); |
| 25 |
| 26 #ifdef SHARED |
| 27 |
| 28 #define MAXP2(a,b) (-(-(a)&-(b))) |
| 29 #define ALIGN(x,y) ((x)+(y)-1 & -(y)) |
| 30 |
| 31 struct debug { |
| 32 int ver; |
| 33 void *head; |
| 34 void (*bp)(void); |
| 35 int state; |
| 36 void *base; |
| 37 }; |
| 38 |
| 39 struct td_index { |
| 40 size_t args[2]; |
| 41 struct td_index *next; |
| 42 }; |
| 43 |
| 44 struct dso { |
| 45 #if DL_FDPIC |
| 46 struct fdpic_loadmap *loadmap; |
| 47 #else |
| 48 unsigned char *base; |
| 49 #endif |
| 50 char *name; |
| 51 size_t *dynv; |
| 52 struct dso *next, *prev; |
| 53 |
| 54 Phdr *phdr; |
| 55 int phnum; |
| 56 size_t phentsize; |
| 57 int refcnt; |
| 58 Sym *syms; |
| 59 uint32_t *hashtab; |
| 60 uint32_t *ghashtab; |
| 61 int16_t *versym; |
| 62 char *strings; |
| 63 unsigned char *map; |
| 64 size_t map_len; |
| 65 dev_t dev; |
| 66 ino_t ino; |
| 67 signed char global; |
| 68 char relocated; |
| 69 char constructed; |
| 70 char kernel_mapped; |
| 71 struct dso **deps, *needed_by; |
| 72 char *rpath_orig, *rpath; |
| 73 struct tls_module tls; |
| 74 size_t tls_id; |
| 75 size_t relro_start, relro_end; |
| 76 void **new_dtv; |
| 77 unsigned char *new_tls; |
| 78 volatile int new_dtv_idx, new_tls_idx; |
| 79 struct td_index *td_index; |
| 80 struct dso *fini_next; |
| 81 char *shortname; |
| 82 #if DL_FDPIC |
| 83 unsigned char *base; |
| 84 #else |
| 85 struct fdpic_loadmap *loadmap; |
| 86 #endif |
| 87 struct funcdesc { |
| 88 void *addr; |
| 89 size_t *got; |
| 90 } *funcdescs; |
| 91 size_t *got; |
| 92 char buf[]; |
| 93 }; |
| 94 |
| 95 struct symdef { |
| 96 Sym *sym; |
| 97 struct dso *dso; |
| 98 }; |
| 99 |
| 100 int __init_tp(void *); |
| 101 void __init_libc(char **, char *); |
| 102 void *__copy_tls(unsigned char *); |
| 103 |
| 104 __attribute__((__visibility__("hidden"))) |
| 105 const char *__libc_get_version(void); |
| 106 |
| 107 static struct builtin_tls { |
| 108 char c; |
| 109 struct pthread pt; |
| 110 void *space[16]; |
| 111 } builtin_tls[1]; |
| 112 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt) |
| 113 |
| 114 #define ADDEND_LIMIT 4096 |
| 115 static size_t *saved_addends, *apply_addends_to; |
| 116 |
| 117 static struct dso ldso; |
| 118 static struct dso *head, *tail, *fini_head; |
| 119 static char *env_path, *sys_path; |
| 120 static unsigned long long gencnt; |
| 121 static int runtime; |
| 122 static int ldd_mode; |
| 123 static int ldso_fail; |
| 124 static int noload; |
| 125 static jmp_buf *rtld_fail; |
| 126 static pthread_rwlock_t lock; |
| 127 static struct debug debug; |
| 128 static struct tls_module *tls_tail; |
| 129 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN; |
| 130 static size_t static_tls_cnt; |
| 131 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE }; |
| 132 static struct fdpic_loadmap *app_loadmap; |
| 133 static struct fdpic_dummy_loadmap app_dummy_loadmap; |
| 134 |
| 135 struct debug *_dl_debug_addr = &debug; |
| 136 |
| 137 __attribute__((__visibility__("hidden"))) |
| 138 void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0; |
| 139 |
| 140 __attribute__((__visibility__("hidden"))) |
| 141 extern void (*const __init_array_end)(void), (*const __fini_array_end)(void); |
| 142 |
| 143 weak_alias(__init_array_start, __init_array_end); |
| 144 weak_alias(__fini_array_start, __fini_array_end); |
| 145 |
| 146 static int dl_strcmp(const char *l, const char *r) |
| 147 { |
| 148 for (; *l==*r && *l; l++, r++); |
| 149 return *(unsigned char *)l - *(unsigned char *)r; |
| 150 } |
| 151 #define strcmp(l,r) dl_strcmp(l,r) |
| 152 |
| 153 /* Compute load address for a virtual address in a given dso. */ |
| 154 #if DL_FDPIC |
| 155 static void *laddr(const struct dso *p, size_t v) |
| 156 { |
| 157 size_t j=0; |
| 158 if (!p->loadmap) return p->base + v; |
| 159 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz;
j++); |
| 160 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].ad
dr); |
| 161 } |
| 162 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \ |
| 163 laddr(p, v), (p)->got }) |
| 164 #else |
| 165 #define laddr(p, v) (void *)((p)->base + (v)) |
| 166 #define fpaddr(p, v) ((void (*)())laddr(p, v)) |
| 167 #endif |
| 168 |
| 169 static void decode_vec(size_t *v, size_t *a, size_t cnt) |
| 170 { |
| 171 size_t i; |
| 172 for (i=0; i<cnt; i++) a[i] = 0; |
| 173 for (; v[0]; v+=2) if (v[0]-1<cnt-1) { |
| 174 a[0] |= 1UL<<v[0]; |
| 175 a[v[0]] = v[1]; |
| 176 } |
| 177 } |
| 178 |
| 179 static int search_vec(size_t *v, size_t *r, size_t key) |
| 180 { |
| 181 for (; v[0]!=key; v+=2) |
| 182 if (!v[0]) return 0; |
| 183 *r = v[1]; |
| 184 return 1; |
| 185 } |
| 186 |
| 187 static uint32_t sysv_hash(const char *s0) |
| 188 { |
| 189 const unsigned char *s = (void *)s0; |
| 190 uint_fast32_t h = 0; |
| 191 while (*s) { |
| 192 h = 16*h + *s++; |
| 193 h ^= h>>24 & 0xf0; |
| 194 } |
| 195 return h & 0xfffffff; |
| 196 } |
| 197 |
| 198 static uint32_t gnu_hash(const char *s0) |
| 199 { |
| 200 const unsigned char *s = (void *)s0; |
| 201 uint_fast32_t h = 5381; |
| 202 for (; *s; s++) |
| 203 h += h*32 + *s; |
| 204 return h; |
| 205 } |
| 206 |
| 207 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso) |
| 208 { |
| 209 size_t i; |
| 210 Sym *syms = dso->syms; |
| 211 uint32_t *hashtab = dso->hashtab; |
| 212 char *strings = dso->strings; |
| 213 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) { |
| 214 if ((!dso->versym || dso->versym[i] >= 0) |
| 215 && (!strcmp(s, strings+syms[i].st_name))) |
| 216 return syms+i; |
| 217 } |
| 218 return 0; |
| 219 } |
| 220 |
| 221 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const ch
ar *s) |
| 222 { |
| 223 uint32_t nbuckets = hashtab[0]; |
| 224 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4); |
| 225 uint32_t i = buckets[h1 % nbuckets]; |
| 226 |
| 227 if (!i) return 0; |
| 228 |
| 229 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]); |
| 230 |
| 231 for (h1 |= 1; ; i++) { |
| 232 uint32_t h2 = *hashval++; |
| 233 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0) |
| 234 && !strcmp(s, dso->strings + dso->syms[i].st_name)) |
| 235 return dso->syms+i; |
| 236 if (h2 & 1) break; |
| 237 } |
| 238 |
| 239 return 0; |
| 240 } |
| 241 |
| 242 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso,
const char *s, uint32_t fofs, size_t fmask) |
| 243 { |
| 244 const size_t *bloomwords = (const void *)(hashtab+4); |
| 245 size_t f = bloomwords[fofs & (hashtab[2]-1)]; |
| 246 if (!(f & fmask)) return 0; |
| 247 |
| 248 f >>= (h1 >> hashtab[3]) % (8 * sizeof f); |
| 249 if (!(f & 1)) return 0; |
| 250 |
| 251 return gnu_lookup(h1, hashtab, dso, s); |
| 252 } |
| 253 |
| 254 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON |
1<<STT_TLS) |
| 255 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE) |
| 256 |
| 257 #ifndef ARCH_SYM_REJECT_UND |
| 258 #define ARCH_SYM_REJECT_UND(s) 0 |
| 259 #endif |
| 260 |
| 261 static struct symdef find_sym(struct dso *dso, const char *s, int need_def) |
| 262 { |
| 263 uint32_t h = 0, gh, gho, *ght; |
| 264 size_t ghm = 0; |
| 265 struct symdef def = {0}; |
| 266 for (; dso; dso=dso->next) { |
| 267 Sym *sym; |
| 268 if (!dso->global) continue; |
| 269 if ((ght = dso->ghashtab)) { |
| 270 if (!ghm) { |
| 271 gh = gnu_hash(s); |
| 272 int maskbits = 8 * sizeof ghm; |
| 273 gho = gh / maskbits; |
| 274 ghm = 1ul << gh % maskbits; |
| 275 } |
| 276 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm); |
| 277 } else { |
| 278 if (!h) h = sysv_hash(s); |
| 279 sym = sysv_lookup(s, h, dso); |
| 280 } |
| 281 if (!sym) continue; |
| 282 if (!sym->st_shndx) |
| 283 if (need_def || (sym->st_info&0xf) == STT_TLS |
| 284 || ARCH_SYM_REJECT_UND(sym)) |
| 285 continue; |
| 286 if (!sym->st_value) |
| 287 if ((sym->st_info&0xf) != STT_TLS) |
| 288 continue; |
| 289 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue; |
| 290 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue; |
| 291 |
| 292 if (def.sym && sym->st_info>>4 == STB_WEAK) continue; |
| 293 def.sym = sym; |
| 294 def.dso = dso; |
| 295 if (sym->st_info>>4 == STB_GLOBAL) break; |
| 296 } |
| 297 return def; |
| 298 } |
| 299 |
| 300 __attribute__((__visibility__("hidden"))) |
| 301 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic(); |
| 302 |
| 303 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
de) |
| 304 { |
| 305 unsigned char *base = dso->base; |
| 306 Sym *syms = dso->syms; |
| 307 char *strings = dso->strings; |
| 308 Sym *sym; |
| 309 const char *name; |
| 310 void *ctx; |
| 311 int type; |
| 312 int sym_index; |
| 313 struct symdef def; |
| 314 size_t *reloc_addr; |
| 315 size_t sym_val; |
| 316 size_t tls_val; |
| 317 size_t addend; |
| 318 int skip_relative = 0, reuse_addends = 0, save_slot = 0; |
| 319 |
| 320 if (dso == &ldso) { |
| 321 /* Only ldso's REL table needs addend saving/reuse. */ |
| 322 if (rel == apply_addends_to) |
| 323 reuse_addends = 1; |
| 324 skip_relative = 1; |
| 325 } |
| 326 |
| 327 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) { |
| 328 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue; |
| 329 type = R_TYPE(rel[1]); |
| 330 if (type == REL_NONE) continue; |
| 331 sym_index = R_SYM(rel[1]); |
| 332 reloc_addr = laddr(dso, rel[0]); |
| 333 if (sym_index) { |
| 334 sym = syms + sym_index; |
| 335 name = strings + sym->st_name; |
| 336 ctx = type==REL_COPY ? head->next : head; |
| 337 def = (sym->st_info&0xf) == STT_SECTION |
| 338 ? (struct symdef){ .dso = dso, .sym = sym } |
| 339 : find_sym(ctx, name, type==REL_PLT); |
| 340 if (!def.sym && (sym->st_shndx != SHN_UNDEF |
| 341 || sym->st_info>>4 != STB_WEAK)) { |
| 342 error("Error relocating %s: %s: symbol not found
", |
| 343 dso->name, name); |
| 344 if (runtime) longjmp(*rtld_fail, 1); |
| 345 continue; |
| 346 } |
| 347 } else { |
| 348 sym = 0; |
| 349 def.sym = 0; |
| 350 def.dso = dso; |
| 351 } |
| 352 |
| 353 if (stride > 2) { |
| 354 addend = rel[2]; |
| 355 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) { |
| 356 addend = 0; |
| 357 } else if (reuse_addends) { |
| 358 /* Save original addend in stage 2 where the dso |
| 359 * chain consists of just ldso; otherwise read back |
| 360 * saved addend since the inline one was clobbered. */ |
| 361 if (head==&ldso) |
| 362 saved_addends[save_slot] = *reloc_addr; |
| 363 addend = saved_addends[save_slot++]; |
| 364 } else { |
| 365 addend = *reloc_addr; |
| 366 } |
| 367 |
| 368 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) :
0; |
| 369 tls_val = def.sym ? def.sym->st_value : 0; |
| 370 |
| 371 switch(type) { |
| 372 case REL_NONE: |
| 373 break; |
| 374 case REL_OFFSET: |
| 375 addend -= (size_t)reloc_addr; |
| 376 case REL_SYMBOLIC: |
| 377 case REL_GOT: |
| 378 case REL_PLT: |
| 379 *reloc_addr = sym_val + addend; |
| 380 break; |
| 381 case REL_RELATIVE: |
| 382 *reloc_addr = (size_t)base + addend; |
| 383 break; |
| 384 case REL_SYM_OR_REL: |
| 385 if (sym) *reloc_addr = sym_val + addend; |
| 386 else *reloc_addr = (size_t)base + addend; |
| 387 break; |
| 388 case REL_COPY: |
| 389 memcpy(reloc_addr, (void *)sym_val, sym->st_size); |
| 390 break; |
| 391 case REL_OFFSET32: |
| 392 *(uint32_t *)reloc_addr = sym_val + addend |
| 393 - (size_t)reloc_addr; |
| 394 break; |
| 395 case REL_FUNCDESC: |
| 396 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs |
| 397 + (def.sym - def.dso->syms)) : 0; |
| 398 break; |
| 399 case REL_FUNCDESC_VAL: |
| 400 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sy
m_val; |
| 401 else *reloc_addr = sym_val; |
| 402 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0; |
| 403 break; |
| 404 case REL_DTPMOD: |
| 405 *reloc_addr = def.dso->tls_id; |
| 406 break; |
| 407 case REL_DTPOFF: |
| 408 *reloc_addr = tls_val + addend - DTP_OFFSET; |
| 409 break; |
| 410 #ifdef TLS_ABOVE_TP |
| 411 case REL_TPOFF: |
| 412 *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K +
addend; |
| 413 break; |
| 414 #else |
| 415 case REL_TPOFF: |
| 416 *reloc_addr = tls_val - def.dso->tls.offset + addend; |
| 417 break; |
| 418 case REL_TPOFF_NEG: |
| 419 *reloc_addr = def.dso->tls.offset - tls_val + addend; |
| 420 break; |
| 421 #endif |
| 422 case REL_TLSDESC: |
| 423 if (stride<3) addend = reloc_addr[1]; |
| 424 if (runtime && def.dso->tls_id >= static_tls_cnt) { |
| 425 struct td_index *new = malloc(sizeof *new); |
| 426 if (!new) { |
| 427 error( |
| 428 "Error relocating %s: cannot allocate TL
SDESC for %s", |
| 429 dso->name, sym ? name : "(local)" ); |
| 430 longjmp(*rtld_fail, 1); |
| 431 } |
| 432 new->next = dso->td_index; |
| 433 dso->td_index = new; |
| 434 new->args[0] = def.dso->tls_id; |
| 435 new->args[1] = tls_val + addend; |
| 436 reloc_addr[0] = (size_t)__tlsdesc_dynamic; |
| 437 reloc_addr[1] = (size_t)new; |
| 438 } else { |
| 439 reloc_addr[0] = (size_t)__tlsdesc_static; |
| 440 #ifdef TLS_ABOVE_TP |
| 441 reloc_addr[1] = tls_val + def.dso->tls.offset |
| 442 + TPOFF_K + addend; |
| 443 #else |
| 444 reloc_addr[1] = tls_val - def.dso->tls.offset |
| 445 + addend; |
| 446 #endif |
| 447 } |
| 448 break; |
| 449 default: |
| 450 error("Error relocating %s: unsupported relocation type
%d", |
| 451 dso->name, type); |
| 452 if (runtime) longjmp(*rtld_fail, 1); |
| 453 continue; |
| 454 } |
| 455 } |
| 456 } |
| 457 |
| 458 /* A huge hack: to make up for the wastefulness of shared libraries |
| 459 * needing at least a page of dirty memory even if they have no global |
| 460 * data, we reclaim the gaps at the beginning and end of writable maps |
| 461 * and "donate" them to the heap by setting up minimal malloc |
| 462 * structures and then freeing them. */ |
| 463 |
| 464 static void reclaim(struct dso *dso, size_t start, size_t end) |
| 465 { |
| 466 size_t *a, *z; |
| 467 if (start >= dso->relro_start && start < dso->relro_end) start = dso->re
lro_end; |
| 468 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relr
o_start; |
| 469 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t); |
| 470 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t); |
| 471 if (start>end || end-start < 4*sizeof(size_t)) return; |
| 472 a = laddr(dso, start); |
| 473 z = laddr(dso, end); |
| 474 a[-2] = 1; |
| 475 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1; |
| 476 z[1] = 1; |
| 477 free(a); |
| 478 } |
| 479 |
| 480 static void reclaim_gaps(struct dso *dso) |
| 481 { |
| 482 Phdr *ph = dso->phdr; |
| 483 size_t phcnt = dso->phnum; |
| 484 |
| 485 if (DL_FDPIC) return; // FIXME |
| 486 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) { |
| 487 if (ph->p_type!=PT_LOAD) continue; |
| 488 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue; |
| 489 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr); |
| 490 reclaim(dso, ph->p_vaddr+ph->p_memsz, |
| 491 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE); |
| 492 } |
| 493 } |
| 494 |
| 495 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t of
f) |
| 496 { |
| 497 static int no_map_fixed; |
| 498 char *q; |
| 499 if (!no_map_fixed) { |
| 500 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off); |
| 501 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL) |
| 502 return q; |
| 503 no_map_fixed = 1; |
| 504 } |
| 505 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */ |
| 506 if (flags & MAP_ANONYMOUS) { |
| 507 memset(p, 0, n); |
| 508 return p; |
| 509 } |
| 510 ssize_t r; |
| 511 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED; |
| 512 for (q=p; n; q+=r, off+=r, n-=r) { |
| 513 r = read(fd, q, n); |
| 514 if (r < 0 && errno != EINTR) return MAP_FAILED; |
| 515 if (!r) { |
| 516 memset(q, 0, n); |
| 517 break; |
| 518 } |
| 519 } |
| 520 return p; |
| 521 } |
| 522 |
| 523 static void unmap_library(struct dso *dso) |
| 524 { |
| 525 if (dso->loadmap) { |
| 526 size_t i; |
| 527 for (i=0; i<dso->loadmap->nsegs; i++) { |
| 528 if (!dso->loadmap->segs[i].p_memsz) |
| 529 continue; |
| 530 munmap((void *)dso->loadmap->segs[i].addr, |
| 531 dso->loadmap->segs[i].p_memsz); |
| 532 } |
| 533 free(dso->loadmap); |
| 534 } else if (dso->map && dso->map_len) { |
| 535 munmap(dso->map, dso->map_len); |
| 536 } |
| 537 } |
| 538 |
| 539 static void *map_library(int fd, struct dso *dso) |
| 540 { |
| 541 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)]; |
| 542 void *allocated_buf=0; |
| 543 size_t phsize; |
| 544 size_t addr_min=SIZE_MAX, addr_max=0, map_len; |
| 545 size_t this_min, this_max; |
| 546 size_t nsegs = 0; |
| 547 off_t off_start; |
| 548 Ehdr *eh; |
| 549 Phdr *ph, *ph0; |
| 550 unsigned prot; |
| 551 unsigned char *map=MAP_FAILED, *base; |
| 552 size_t dyn=0; |
| 553 size_t tls_image=0; |
| 554 size_t i; |
| 555 |
| 556 ssize_t l = read(fd, buf, sizeof buf); |
| 557 eh = buf; |
| 558 if (l<0) return 0; |
| 559 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC)) |
| 560 goto noexec; |
| 561 phsize = eh->e_phentsize * eh->e_phnum; |
| 562 if (phsize > sizeof buf - sizeof *eh) { |
| 563 allocated_buf = malloc(phsize); |
| 564 if (!allocated_buf) return 0; |
| 565 l = pread(fd, allocated_buf, phsize, eh->e_phoff); |
| 566 if (l < 0) goto error; |
| 567 if (l != phsize) goto noexec; |
| 568 ph = ph0 = allocated_buf; |
| 569 } else if (eh->e_phoff + phsize > l) { |
| 570 l = pread(fd, buf+1, phsize, eh->e_phoff); |
| 571 if (l < 0) goto error; |
| 572 if (l != phsize) goto noexec; |
| 573 ph = ph0 = (void *)(buf + 1); |
| 574 } else { |
| 575 ph = ph0 = (void *)((char *)buf + eh->e_phoff); |
| 576 } |
| 577 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) { |
| 578 if (ph->p_type == PT_DYNAMIC) { |
| 579 dyn = ph->p_vaddr; |
| 580 } else if (ph->p_type == PT_TLS) { |
| 581 tls_image = ph->p_vaddr; |
| 582 dso->tls.align = ph->p_align; |
| 583 dso->tls.len = ph->p_filesz; |
| 584 dso->tls.size = ph->p_memsz; |
| 585 } else if (ph->p_type == PT_GNU_RELRO) { |
| 586 dso->relro_start = ph->p_vaddr & -PAGE_SIZE; |
| 587 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZ
E; |
| 588 } |
| 589 if (ph->p_type != PT_LOAD) continue; |
| 590 nsegs++; |
| 591 if (ph->p_vaddr < addr_min) { |
| 592 addr_min = ph->p_vaddr; |
| 593 off_start = ph->p_offset; |
| 594 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) | |
| 595 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) | |
| 596 ((ph->p_flags&PF_X) ? PROT_EXEC : 0)); |
| 597 } |
| 598 if (ph->p_vaddr+ph->p_memsz > addr_max) { |
| 599 addr_max = ph->p_vaddr+ph->p_memsz; |
| 600 } |
| 601 } |
| 602 if (!dyn) goto noexec; |
| 603 if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) { |
| 604 dso->loadmap = calloc(1, sizeof *dso->loadmap |
| 605 + nsegs * sizeof *dso->loadmap->segs); |
| 606 if (!dso->loadmap) goto error; |
| 607 dso->loadmap->nsegs = nsegs; |
| 608 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsiz
e)) { |
| 609 if (ph->p_type != PT_LOAD) continue; |
| 610 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) | |
| 611 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) | |
| 612 ((ph->p_flags&PF_X) ? PROT_EXEC : 0)); |
| 613 map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1), |
| 614 prot, MAP_PRIVATE, |
| 615 fd, ph->p_offset & -PAGE_SIZE); |
| 616 if (map == MAP_FAILED) { |
| 617 unmap_library(dso); |
| 618 goto error; |
| 619 } |
| 620 dso->loadmap->segs[i].addr = (size_t)map + |
| 621 (ph->p_vaddr & PAGE_SIZE-1); |
| 622 dso->loadmap->segs[i].p_vaddr = ph->p_vaddr; |
| 623 dso->loadmap->segs[i].p_memsz = ph->p_memsz; |
| 624 i++; |
| 625 if (prot & PROT_WRITE) { |
| 626 size_t brk = (ph->p_vaddr & PAGE_SIZE-1) |
| 627 + ph->p_filesz; |
| 628 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE; |
| 629 size_t pgend = brk + ph->p_memsz - ph->p_filesz |
| 630 + PAGE_SIZE-1 & -PAGE_SIZE; |
| 631 if (pgend > pgbrk && mmap_fixed(map+pgbrk, |
| 632 pgend-pgbrk, prot, |
| 633 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, |
| 634 -1, off_start) == MAP_FAILED) |
| 635 goto error; |
| 636 memset(map + brk, 0, pgbrk-brk); |
| 637 } |
| 638 } |
| 639 map = (void *)dso->loadmap->segs[0].addr; |
| 640 map_len = 0; |
| 641 goto done_mapping; |
| 642 } |
| 643 addr_max += PAGE_SIZE-1; |
| 644 addr_max &= -PAGE_SIZE; |
| 645 addr_min &= -PAGE_SIZE; |
| 646 off_start &= -PAGE_SIZE; |
| 647 map_len = addr_max - addr_min + off_start; |
| 648 /* The first time, we map too much, possibly even more than |
| 649 * the length of the file. This is okay because we will not |
| 650 * use the invalid part; we just need to reserve the right |
| 651 * amount of virtual address space to map over later. */ |
| 652 map = DL_NOMMU_SUPPORT |
| 653 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC
, |
| 654 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) |
| 655 : mmap((void *)addr_min, map_len, prot, |
| 656 MAP_PRIVATE, fd, off_start); |
| 657 if (map==MAP_FAILED) goto error; |
| 658 dso->map = map; |
| 659 dso->map_len = map_len; |
| 660 /* If the loaded file is not relocatable and the requested address is |
| 661 * not available, then the load operation must fail. */ |
| 662 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) { |
| 663 errno = EBUSY; |
| 664 goto error; |
| 665 } |
| 666 base = map - addr_min; |
| 667 dso->phdr = 0; |
| 668 dso->phnum = 0; |
| 669 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsi
ze)) { |
| 670 if (ph->p_type != PT_LOAD) continue; |
| 671 /* Check if the programs headers are in this load segment, and |
| 672 * if so, record the address for use by dl_iterate_phdr. */ |
| 673 if (!dso->phdr && eh->e_phoff >= ph->p_offset |
| 674 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) { |
| 675 dso->phdr = (void *)(base + ph->p_vaddr |
| 676 + (eh->e_phoff-ph->p_offset)); |
| 677 dso->phnum = eh->e_phnum; |
| 678 dso->phentsize = eh->e_phentsize; |
| 679 } |
| 680 /* Reuse the existing mapping for the lowest-address LOAD */ |
| 681 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT) |
| 682 continue; |
| 683 this_min = ph->p_vaddr & -PAGE_SIZE; |
| 684 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE; |
| 685 off_start = ph->p_offset & -PAGE_SIZE; |
| 686 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) | |
| 687 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) | |
| 688 ((ph->p_flags&PF_X) ? PROT_EXEC : 0)); |
| 689 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVA
TE|MAP_FIXED, fd, off_start) == MAP_FAILED) |
| 690 goto error; |
| 691 if (ph->p_memsz > ph->p_filesz) { |
| 692 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz; |
| 693 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE; |
| 694 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1); |
| 695 if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)
pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -
1, 0) == MAP_FAILED) |
| 696 goto error; |
| 697 } |
| 698 } |
| 699 for (i=0; ((size_t *)(base+dyn))[i]; i+=2) |
| 700 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) { |
| 701 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXE
C) |
| 702 && errno != ENOSYS) |
| 703 goto error; |
| 704 break; |
| 705 } |
| 706 done_mapping: |
| 707 dso->base = base; |
| 708 dso->dynv = laddr(dso, dyn); |
| 709 if (dso->tls.size) dso->tls.image = laddr(dso, tls_image); |
| 710 if (!runtime) reclaim_gaps(dso); |
| 711 free(allocated_buf); |
| 712 return map; |
| 713 noexec: |
| 714 errno = ENOEXEC; |
| 715 error: |
| 716 if (map!=MAP_FAILED) unmap_library(dso); |
| 717 free(allocated_buf); |
| 718 return 0; |
| 719 } |
| 720 |
| 721 static int path_open(const char *name, const char *s, char *buf, size_t buf_size
) |
| 722 { |
| 723 size_t l; |
| 724 int fd; |
| 725 for (;;) { |
| 726 s += strspn(s, ":\n"); |
| 727 l = strcspn(s, ":\n"); |
| 728 if (l-1 >= INT_MAX) return -1; |
| 729 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_si
ze) { |
| 730 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd; |
| 731 switch (errno) { |
| 732 case ENOENT: |
| 733 case ENOTDIR: |
| 734 case EACCES: |
| 735 case ENAMETOOLONG: |
| 736 break; |
| 737 default: |
| 738 /* Any negative value but -1 will inhibit |
| 739 * futher path search. */ |
| 740 return -2; |
| 741 } |
| 742 } |
| 743 s += l; |
| 744 } |
| 745 } |
| 746 |
| 747 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size) |
| 748 { |
| 749 size_t n, l; |
| 750 const char *s, *t, *origin; |
| 751 char *d; |
| 752 if (p->rpath || !p->rpath_orig) return 0; |
| 753 if (!strchr(p->rpath_orig, '$')) { |
| 754 p->rpath = p->rpath_orig; |
| 755 return 0; |
| 756 } |
| 757 n = 0; |
| 758 s = p->rpath_orig; |
| 759 while ((t=strchr(s, '$'))) { |
| 760 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9)) |
| 761 return 0; |
| 762 s = t+1; |
| 763 n++; |
| 764 } |
| 765 if (n > SSIZE_MAX/PATH_MAX) return 0; |
| 766 |
| 767 if (p->kernel_mapped) { |
| 768 /* $ORIGIN searches cannot be performed for the main program |
| 769 * when it is suid/sgid/AT_SECURE. This is because the |
| 770 * pathname is under the control of the caller of execve. |
| 771 * For libraries, however, $ORIGIN can be processed safely |
| 772 * since the library's pathname came from a trusted source |
| 773 * (either system paths or a call to dlopen). */ |
| 774 if (libc.secure) |
| 775 return 0; |
| 776 l = readlink("/proc/self/exe", buf, buf_size); |
| 777 if (l == -1) switch (errno) { |
| 778 case ENOENT: |
| 779 case ENOTDIR: |
| 780 case EACCES: |
| 781 break; |
| 782 default: |
| 783 return -1; |
| 784 } |
| 785 if (l >= buf_size) |
| 786 return 0; |
| 787 buf[l] = 0; |
| 788 origin = buf; |
| 789 } else { |
| 790 origin = p->name; |
| 791 } |
| 792 t = strrchr(origin, '/'); |
| 793 l = t ? t-origin : 0; |
| 794 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1); |
| 795 if (!p->rpath) return -1; |
| 796 |
| 797 d = p->rpath; |
| 798 s = p->rpath_orig; |
| 799 while ((t=strchr(s, '$'))) { |
| 800 memcpy(d, s, t-s); |
| 801 d += t-s; |
| 802 memcpy(d, origin, l); |
| 803 d += l; |
| 804 /* It was determined previously that the '$' is followed |
| 805 * either by "ORIGIN" or "{ORIGIN}". */ |
| 806 s = t + 7 + 2*(t[1]=='{'); |
| 807 } |
| 808 strcpy(d, s); |
| 809 return 0; |
| 810 } |
| 811 |
| 812 static void decode_dyn(struct dso *p) |
| 813 { |
| 814 size_t dyn[DYN_CNT]; |
| 815 decode_vec(p->dynv, dyn, DYN_CNT); |
| 816 p->syms = laddr(p, dyn[DT_SYMTAB]); |
| 817 p->strings = laddr(p, dyn[DT_STRTAB]); |
| 818 if (dyn[0]&(1<<DT_HASH)) |
| 819 p->hashtab = laddr(p, dyn[DT_HASH]); |
| 820 if (dyn[0]&(1<<DT_RPATH)) |
| 821 p->rpath_orig = p->strings + dyn[DT_RPATH]; |
| 822 if (dyn[0]&(1<<DT_RUNPATH)) |
| 823 p->rpath_orig = p->strings + dyn[DT_RUNPATH]; |
| 824 if (dyn[0]&(1<<DT_PLTGOT)) |
| 825 p->got = laddr(p, dyn[DT_PLTGOT]); |
| 826 if (search_vec(p->dynv, dyn, DT_GNU_HASH)) |
| 827 p->ghashtab = laddr(p, *dyn); |
| 828 if (search_vec(p->dynv, dyn, DT_VERSYM)) |
| 829 p->versym = laddr(p, *dyn); |
| 830 } |
| 831 |
| 832 static size_t count_syms(struct dso *p) |
| 833 { |
| 834 if (p->hashtab) return p->hashtab[1]; |
| 835 |
| 836 size_t nsym, i; |
| 837 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4); |
| 838 uint32_t *hashval; |
| 839 for (i = nsym = 0; i < p->ghashtab[0]; i++) { |
| 840 if (buckets[i] > nsym) |
| 841 nsym = buckets[i]; |
| 842 } |
| 843 if (nsym) { |
| 844 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]); |
| 845 do nsym++; |
| 846 while (!(*hashval++ & 1)); |
| 847 } |
| 848 return nsym; |
| 849 } |
| 850 |
| 851 static void *dl_mmap(size_t n) |
| 852 { |
| 853 void *p; |
| 854 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE; |
| 855 #ifdef SYS_mmap2 |
| 856 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0); |
| 857 #else |
| 858 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0); |
| 859 #endif |
| 860 return p == MAP_FAILED ? 0 : p; |
| 861 } |
| 862 |
| 863 static void makefuncdescs(struct dso *p) |
| 864 { |
| 865 static int self_done; |
| 866 size_t nsym = count_syms(p); |
| 867 size_t i, size = nsym * sizeof(*p->funcdescs); |
| 868 |
| 869 if (!self_done) { |
| 870 p->funcdescs = dl_mmap(size); |
| 871 self_done = 1; |
| 872 } else { |
| 873 p->funcdescs = malloc(size); |
| 874 } |
| 875 if (!p->funcdescs) { |
| 876 if (!runtime) a_crash(); |
| 877 error("Error allocating function descriptors for %s", p->name); |
| 878 longjmp(*rtld_fail, 1); |
| 879 } |
| 880 for (i=0; i<nsym; i++) { |
| 881 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) { |
| 882 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value); |
| 883 p->funcdescs[i].got = p->got; |
| 884 } else { |
| 885 p->funcdescs[i].addr = 0; |
| 886 p->funcdescs[i].got = 0; |
| 887 } |
| 888 } |
| 889 } |
| 890 |
| 891 static struct dso *load_library(const char *name, struct dso *needed_by) |
| 892 { |
| 893 char buf[2*NAME_MAX+2]; |
| 894 const char *pathname; |
| 895 unsigned char *map; |
| 896 struct dso *p, temp_dso = {0}; |
| 897 int fd; |
| 898 struct stat st; |
| 899 size_t alloc_size; |
| 900 int n_th = 0; |
| 901 int is_self = 0; |
| 902 |
| 903 if (!*name) { |
| 904 errno = EINVAL; |
| 905 return 0; |
| 906 } |
| 907 |
| 908 /* Catch and block attempts to reload the implementation itself */ |
| 909 if (name[0]=='l' && name[1]=='i' && name[2]=='b') { |
| 910 static const char *rp, reserved[] = |
| 911 "c\0pthread\0rt\0m\0dl\0util\0xnet\0"; |
| 912 char *z = strchr(name, '.'); |
| 913 if (z) { |
| 914 size_t l = z-name; |
| 915 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=s
trlen(rp)+1); |
| 916 if (*rp) { |
| 917 if (ldd_mode) { |
| 918 /* Track which names have been resolved |
| 919 * and only report each one once. */ |
| 920 static unsigned reported; |
| 921 unsigned mask = 1U<<(rp-reserved); |
| 922 if (!(reported & mask)) { |
| 923 reported |= mask; |
| 924 dprintf(1, "\t%s => %s (%p)\n", |
| 925 name, ldso.name, |
| 926 ldso.base); |
| 927 } |
| 928 } |
| 929 is_self = 1; |
| 930 } |
| 931 } |
| 932 } |
| 933 if (!strcmp(name, ldso.name)) is_self = 1; |
| 934 if (is_self) { |
| 935 if (!ldso.prev) { |
| 936 tail->next = &ldso; |
| 937 ldso.prev = tail; |
| 938 tail = ldso.next ? ldso.next : &ldso; |
| 939 } |
| 940 return &ldso; |
| 941 } |
| 942 if (strchr(name, '/')) { |
| 943 pathname = name; |
| 944 fd = open(name, O_RDONLY|O_CLOEXEC); |
| 945 } else { |
| 946 /* Search for the name to see if it's already loaded */ |
| 947 for (p=head->next; p; p=p->next) { |
| 948 if (p->shortname && !strcmp(p->shortname, name)) { |
| 949 p->refcnt++; |
| 950 return p; |
| 951 } |
| 952 } |
| 953 if (strlen(name) > NAME_MAX) return 0; |
| 954 fd = -1; |
| 955 if (env_path) fd = path_open(name, env_path, buf, sizeof buf); |
| 956 for (p=needed_by; fd == -1 && p; p=p->needed_by) { |
| 957 if (fixup_rpath(p, buf, sizeof buf) < 0) |
| 958 fd = -2; /* Inhibit further search. */ |
| 959 if (p->rpath) |
| 960 fd = path_open(name, p->rpath, buf, sizeof buf); |
| 961 } |
| 962 if (fd == -1) { |
| 963 if (!sys_path) { |
| 964 char *prefix = 0; |
| 965 size_t prefix_len; |
| 966 if (ldso.name[0]=='/') { |
| 967 char *s, *t, *z; |
| 968 for (s=t=z=ldso.name; *s; s++) |
| 969 if (*s=='/') z=t, t=s; |
| 970 prefix_len = z-ldso.name; |
| 971 if (prefix_len < PATH_MAX) |
| 972 prefix = ldso.name; |
| 973 } |
| 974 if (!prefix) { |
| 975 prefix = ""; |
| 976 prefix_len = 0; |
| 977 } |
| 978 char etc_ldso_path[prefix_len + 1 |
| 979 + sizeof "/etc/ld-musl-" LDSO_ARCH ".pat
h"]; |
| 980 snprintf(etc_ldso_path, sizeof etc_ldso_path, |
| 981 "%.*s/etc/ld-musl-" LDSO_ARCH ".path", |
| 982 (int)prefix_len, prefix); |
| 983 FILE *f = fopen(etc_ldso_path, "rbe"); |
| 984 if (f) { |
| 985 if (getdelim(&sys_path, (size_t[1]){0},
0, f) <= 0) { |
| 986 free(sys_path); |
| 987 sys_path = ""; |
| 988 } |
| 989 fclose(f); |
| 990 } else if (errno != ENOENT) { |
| 991 sys_path = ""; |
| 992 } |
| 993 } |
| 994 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib"
; |
| 995 fd = path_open(name, sys_path, buf, sizeof buf); |
| 996 } |
| 997 pathname = buf; |
| 998 } |
| 999 if (fd < 0) return 0; |
| 1000 if (fstat(fd, &st) < 0) { |
| 1001 close(fd); |
| 1002 return 0; |
| 1003 } |
| 1004 for (p=head->next; p; p=p->next) { |
| 1005 if (p->dev == st.st_dev && p->ino == st.st_ino) { |
| 1006 /* If this library was previously loaded with a |
| 1007 * pathname but a search found the same inode, |
| 1008 * setup its shortname so it can be found by name. */ |
| 1009 if (!p->shortname && pathname != name) |
| 1010 p->shortname = strrchr(p->name, '/')+1; |
| 1011 close(fd); |
| 1012 p->refcnt++; |
| 1013 return p; |
| 1014 } |
| 1015 } |
| 1016 map = noload ? 0 : map_library(fd, &temp_dso); |
| 1017 close(fd); |
| 1018 if (!map) return 0; |
| 1019 |
| 1020 /* Allocate storage for the new DSO. When there is TLS, this |
| 1021 * storage must include a reservation for all pre-existing |
| 1022 * threads to obtain copies of both the new TLS, and an |
| 1023 * extended DTV capable of storing an additional slot for |
| 1024 * the newly-loaded DSO. */ |
| 1025 alloc_size = sizeof *p + strlen(pathname) + 1; |
| 1026 if (runtime && temp_dso.tls.image) { |
| 1027 size_t per_th = temp_dso.tls.size + temp_dso.tls.align |
| 1028 + sizeof(void *) * (tls_cnt+3); |
| 1029 n_th = libc.threads_minus_1 + 1; |
| 1030 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX; |
| 1031 else alloc_size += n_th * per_th; |
| 1032 } |
| 1033 p = calloc(1, alloc_size); |
| 1034 if (!p) { |
| 1035 unmap_library(&temp_dso); |
| 1036 return 0; |
| 1037 } |
| 1038 memcpy(p, &temp_dso, sizeof temp_dso); |
| 1039 decode_dyn(p); |
| 1040 p->dev = st.st_dev; |
| 1041 p->ino = st.st_ino; |
| 1042 p->refcnt = 1; |
| 1043 p->needed_by = needed_by; |
| 1044 p->name = p->buf; |
| 1045 strcpy(p->name, pathname); |
| 1046 /* Add a shortname only if name arg was not an explicit pathname. */ |
| 1047 if (pathname != name) p->shortname = strrchr(p->name, '/')+1; |
| 1048 if (p->tls.image) { |
| 1049 p->tls_id = ++tls_cnt; |
| 1050 tls_align = MAXP2(tls_align, p->tls.align); |
| 1051 #ifdef TLS_ABOVE_TP |
| 1052 p->tls.offset = tls_offset + ( (tls_align-1) & |
| 1053 -(tls_offset + (uintptr_t)p->tls.image) ); |
| 1054 tls_offset += p->tls.size; |
| 1055 #else |
| 1056 tls_offset += p->tls.size + p->tls.align - 1; |
| 1057 tls_offset -= (tls_offset + (uintptr_t)p->tls.image) |
| 1058 & (p->tls.align-1); |
| 1059 p->tls.offset = tls_offset; |
| 1060 #endif |
| 1061 p->new_dtv = (void *)(-sizeof(size_t) & |
| 1062 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t))); |
| 1063 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1)); |
| 1064 if (tls_tail) tls_tail->next = &p->tls; |
| 1065 else libc.tls_head = &p->tls; |
| 1066 tls_tail = &p->tls; |
| 1067 } |
| 1068 |
| 1069 tail->next = p; |
| 1070 p->prev = tail; |
| 1071 tail = p; |
| 1072 |
| 1073 if (DL_FDPIC) makefuncdescs(p); |
| 1074 |
| 1075 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base); |
| 1076 |
| 1077 return p; |
| 1078 } |
| 1079 |
| 1080 static void load_deps(struct dso *p) |
| 1081 { |
| 1082 size_t i, ndeps=0; |
| 1083 struct dso ***deps = &p->deps, **tmp, *dep; |
| 1084 for (; p; p=p->next) { |
| 1085 for (i=0; p->dynv[i]; i+=2) { |
| 1086 if (p->dynv[i] != DT_NEEDED) continue; |
| 1087 dep = load_library(p->strings + p->dynv[i+1], p); |
| 1088 if (!dep) { |
| 1089 error("Error loading shared library %s: %m (need
ed by %s)", |
| 1090 p->strings + p->dynv[i+1], p->name); |
| 1091 if (runtime) longjmp(*rtld_fail, 1); |
| 1092 continue; |
| 1093 } |
| 1094 if (runtime) { |
| 1095 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2)); |
| 1096 if (!tmp) longjmp(*rtld_fail, 1); |
| 1097 tmp[ndeps++] = dep; |
| 1098 tmp[ndeps] = 0; |
| 1099 *deps = tmp; |
| 1100 } |
| 1101 } |
| 1102 } |
| 1103 } |
| 1104 |
| 1105 static void load_preload(char *s) |
| 1106 { |
| 1107 int tmp; |
| 1108 char *z; |
| 1109 for (z=s; *z; s=z) { |
| 1110 for ( ; *s && (isspace(*s) || *s==':'); s++); |
| 1111 for (z=s; *z && !isspace(*z) && *z!=':'; z++); |
| 1112 tmp = *z; |
| 1113 *z = 0; |
| 1114 load_library(s, 0); |
| 1115 *z = tmp; |
| 1116 } |
| 1117 } |
| 1118 |
| 1119 static void make_global(struct dso *p) |
| 1120 { |
| 1121 for (; p; p=p->next) p->global = 1; |
| 1122 } |
| 1123 |
| 1124 static void do_mips_relocs(struct dso *p, size_t *got) |
| 1125 { |
| 1126 size_t i, j, rel[2]; |
| 1127 unsigned char *base = p->base; |
| 1128 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO); |
| 1129 if (p==&ldso) { |
| 1130 got += i; |
| 1131 } else { |
| 1132 while (i--) *got++ += (size_t)base; |
| 1133 } |
| 1134 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM); |
| 1135 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO); |
| 1136 Sym *sym = p->syms + j; |
| 1137 rel[0] = (unsigned char *)got - base; |
| 1138 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) { |
| 1139 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT; |
| 1140 do_relocs(p, rel, sizeof rel, 2); |
| 1141 } |
| 1142 } |
| 1143 |
| 1144 static void reloc_all(struct dso *p) |
| 1145 { |
| 1146 size_t dyn[DYN_CNT]; |
| 1147 for (; p; p=p->next) { |
| 1148 if (p->relocated) continue; |
| 1149 decode_vec(p->dynv, dyn, DYN_CNT); |
| 1150 if (NEED_MIPS_GOT_RELOCS) |
| 1151 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT])); |
| 1152 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ], |
| 1153 2+(dyn[DT_PLTREL]==DT_RELA)); |
| 1154 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2); |
| 1155 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3); |
| 1156 |
| 1157 if (head != &ldso && p->relro_start != p->relro_end && |
| 1158 mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_sta
rt, PROT_READ) |
| 1159 && errno != ENOSYS) { |
| 1160 error("Error relocating %s: RELRO protection failed: %m"
, |
| 1161 p->name); |
| 1162 if (runtime) longjmp(*rtld_fail, 1); |
| 1163 } |
| 1164 |
| 1165 p->relocated = 1; |
| 1166 } |
| 1167 } |
| 1168 |
| 1169 static void kernel_mapped_dso(struct dso *p) |
| 1170 { |
| 1171 size_t min_addr = -1, max_addr = 0, cnt; |
| 1172 Phdr *ph = p->phdr; |
| 1173 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) { |
| 1174 if (ph->p_type == PT_DYNAMIC) { |
| 1175 p->dynv = laddr(p, ph->p_vaddr); |
| 1176 } else if (ph->p_type == PT_GNU_RELRO) { |
| 1177 p->relro_start = ph->p_vaddr & -PAGE_SIZE; |
| 1178 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE; |
| 1179 } |
| 1180 if (ph->p_type != PT_LOAD) continue; |
| 1181 if (ph->p_vaddr < min_addr) |
| 1182 min_addr = ph->p_vaddr; |
| 1183 if (ph->p_vaddr+ph->p_memsz > max_addr) |
| 1184 max_addr = ph->p_vaddr+ph->p_memsz; |
| 1185 } |
| 1186 min_addr &= -PAGE_SIZE; |
| 1187 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE; |
| 1188 p->map = p->base + min_addr; |
| 1189 p->map_len = max_addr - min_addr; |
| 1190 p->kernel_mapped = 1; |
| 1191 } |
| 1192 |
| 1193 void __libc_exit_fini() |
| 1194 { |
| 1195 struct dso *p; |
| 1196 size_t dyn[DYN_CNT]; |
| 1197 for (p=fini_head; p; p=p->fini_next) { |
| 1198 if (!p->constructed) continue; |
| 1199 decode_vec(p->dynv, dyn, DYN_CNT); |
| 1200 if (dyn[0] & (1<<DT_FINI_ARRAY)) { |
| 1201 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t); |
| 1202 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n; |
| 1203 while (n--) ((void (*)(void))*--fn)(); |
| 1204 } |
| 1205 #ifndef NO_LEGACY_INITFINI |
| 1206 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI]) |
| 1207 fpaddr(p, dyn[DT_FINI])(); |
| 1208 #endif |
| 1209 } |
| 1210 } |
| 1211 |
| 1212 static void do_init_fini(struct dso *p) |
| 1213 { |
| 1214 size_t dyn[DYN_CNT]; |
| 1215 int need_locking = libc.threads_minus_1; |
| 1216 /* Allow recursive calls that arise when a library calls |
| 1217 * dlopen from one of its constructors, but block any |
| 1218 * other threads until all ctors have finished. */ |
| 1219 if (need_locking) pthread_mutex_lock(&init_fini_lock); |
| 1220 for (; p; p=p->prev) { |
| 1221 if (p->constructed) continue; |
| 1222 p->constructed = 1; |
| 1223 decode_vec(p->dynv, dyn, DYN_CNT); |
| 1224 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) { |
| 1225 p->fini_next = fini_head; |
| 1226 fini_head = p; |
| 1227 } |
| 1228 #ifndef NO_LEGACY_INITFINI |
| 1229 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT]) |
| 1230 fpaddr(p, dyn[DT_INIT])(); |
| 1231 #endif |
| 1232 if (dyn[0] & (1<<DT_INIT_ARRAY)) { |
| 1233 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t); |
| 1234 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]); |
| 1235 while (n--) ((void (*)(void))*fn++)(); |
| 1236 } |
| 1237 if (!need_locking && libc.threads_minus_1) { |
| 1238 need_locking = 1; |
| 1239 pthread_mutex_lock(&init_fini_lock); |
| 1240 } |
| 1241 } |
| 1242 if (need_locking) pthread_mutex_unlock(&init_fini_lock); |
| 1243 } |
| 1244 |
| 1245 void __libc_start_init(void) |
| 1246 { |
| 1247 do_init_fini(tail); |
| 1248 } |
| 1249 |
| 1250 static void dl_debug_state(void) |
| 1251 { |
| 1252 } |
| 1253 |
| 1254 weak_alias(dl_debug_state, _dl_debug_state); |
| 1255 |
| 1256 void __init_tls(size_t *auxv) |
| 1257 { |
| 1258 } |
| 1259 |
| 1260 __attribute__((__visibility__("hidden"))) |
| 1261 void *__tls_get_new(size_t *v) |
| 1262 { |
| 1263 pthread_t self = __pthread_self(); |
| 1264 |
| 1265 /* Block signals to make accessing new TLS async-signal-safe */ |
| 1266 sigset_t set; |
| 1267 __block_all_sigs(&set); |
| 1268 if (v[0]<=(size_t)self->dtv[0]) { |
| 1269 __restore_sigs(&set); |
| 1270 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET; |
| 1271 } |
| 1272 |
| 1273 /* This is safe without any locks held because, if the caller |
| 1274 * is able to request the Nth entry of the DTV, the DSO list |
| 1275 * must be valid at least that far out and it was synchronized |
| 1276 * at program startup or by an already-completed call to dlopen. */ |
| 1277 struct dso *p; |
| 1278 for (p=head; p->tls_id != v[0]; p=p->next); |
| 1279 |
| 1280 /* Get new DTV space from new DSO if needed */ |
| 1281 if (v[0] > (size_t)self->dtv[0]) { |
| 1282 void **newdtv = p->new_dtv + |
| 1283 (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1); |
| 1284 memcpy(newdtv, self->dtv, |
| 1285 ((size_t)self->dtv[0]+1) * sizeof(void *)); |
| 1286 newdtv[0] = (void *)v[0]; |
| 1287 self->dtv = self->dtv_copy = newdtv; |
| 1288 } |
| 1289 |
| 1290 /* Get new TLS memory from all new DSOs up to the requested one */ |
| 1291 unsigned char *mem; |
| 1292 for (p=head; ; p=p->next) { |
| 1293 if (!p->tls_id || self->dtv[p->tls_id]) continue; |
| 1294 mem = p->new_tls + (p->tls.size + p->tls.align) |
| 1295 * a_fetch_add(&p->new_tls_idx,1); |
| 1296 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem) |
| 1297 & (p->tls.align-1); |
| 1298 self->dtv[p->tls_id] = mem; |
| 1299 memcpy(mem, p->tls.image, p->tls.len); |
| 1300 if (p->tls_id == v[0]) break; |
| 1301 } |
| 1302 __restore_sigs(&set); |
| 1303 return mem + v[1] + DTP_OFFSET; |
| 1304 } |
| 1305 |
| 1306 static void update_tls_size() |
| 1307 { |
| 1308 libc.tls_cnt = tls_cnt; |
| 1309 libc.tls_align = tls_align; |
| 1310 libc.tls_size = ALIGN( |
| 1311 (1+tls_cnt) * sizeof(void *) + |
| 1312 tls_offset + |
| 1313 sizeof(struct pthread) + |
| 1314 tls_align * 2, |
| 1315 tls_align); |
| 1316 } |
| 1317 |
| 1318 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the |
| 1319 * following stage 2 and stage 3 functions via primitive symbolic lookup |
| 1320 * since it does not have access to their addresses to begin with. */ |
| 1321 |
| 1322 /* Stage 2 of the dynamic linker is called after relative relocations |
| 1323 * have been processed. It can make function calls to static functions |
| 1324 * and access string literals and static data, but cannot use extern |
| 1325 * symbols. Its job is to perform symbolic relocations on the dynamic |
| 1326 * linker itself, but some of the relocations performed may need to be |
| 1327 * replaced later due to copy relocations in the main program. */ |
| 1328 |
| 1329 __attribute__((__visibility__("hidden"))) |
| 1330 void __dls2(unsigned char *base, size_t *sp) |
| 1331 { |
| 1332 if (DL_FDPIC) { |
| 1333 void *p1 = (void *)sp[-2]; |
| 1334 void *p2 = (void *)sp[-1]; |
| 1335 if (!p1) { |
| 1336 size_t *auxv, aux[AUX_CNT]; |
| 1337 for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++; |
| 1338 decode_vec(auxv, aux, AUX_CNT); |
| 1339 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE]; |
| 1340 else ldso.base = (void *)(aux[AT_PHDR] & -4096); |
| 1341 } |
| 1342 app_loadmap = p2 ? p1 : 0; |
| 1343 ldso.loadmap = p2 ? p2 : p1; |
| 1344 ldso.base = laddr(&ldso, 0); |
| 1345 } else { |
| 1346 ldso.base = base; |
| 1347 } |
| 1348 Ehdr *ehdr = (void *)ldso.base; |
| 1349 ldso.name = ldso.shortname = "libc.so"; |
| 1350 ldso.global = 1; |
| 1351 ldso.phnum = ehdr->e_phnum; |
| 1352 ldso.phdr = laddr(&ldso, ehdr->e_phoff); |
| 1353 ldso.phentsize = ehdr->e_phentsize; |
| 1354 kernel_mapped_dso(&ldso); |
| 1355 decode_dyn(&ldso); |
| 1356 |
| 1357 if (DL_FDPIC) makefuncdescs(&ldso); |
| 1358 |
| 1359 /* Prepare storage for to save clobbered REL addends so they |
| 1360 * can be reused in stage 3. There should be very few. If |
| 1361 * something goes wrong and there are a huge number, abort |
| 1362 * instead of risking stack overflow. */ |
| 1363 size_t dyn[DYN_CNT]; |
| 1364 decode_vec(ldso.dynv, dyn, DYN_CNT); |
| 1365 size_t *rel = laddr(&ldso, dyn[DT_REL]); |
| 1366 size_t rel_size = dyn[DT_RELSZ]; |
| 1367 size_t symbolic_rel_cnt = 0; |
| 1368 apply_addends_to = rel; |
| 1369 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t)) |
| 1370 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++; |
| 1371 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash(); |
| 1372 size_t addends[symbolic_rel_cnt+1]; |
| 1373 saved_addends = addends; |
| 1374 |
| 1375 head = &ldso; |
| 1376 reloc_all(&ldso); |
| 1377 |
| 1378 ldso.relocated = 0; |
| 1379 |
| 1380 /* Call dynamic linker stage-3, __dls3, looking it up |
| 1381 * symbolically as a barrier against moving the address |
| 1382 * load across the above relocation processing. */ |
| 1383 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0); |
| 1384 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp)
; |
| 1385 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp); |
| 1386 } |
| 1387 |
| 1388 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc |
| 1389 * fully functional. Its job is to load (if not already loaded) and |
| 1390 * process dependencies and relocations for the main application and |
| 1391 * transfer control to its entry point. */ |
| 1392 |
| 1393 _Noreturn void __dls3(size_t *sp) |
| 1394 { |
| 1395 static struct dso app, vdso; |
| 1396 size_t aux[AUX_CNT], *auxv; |
| 1397 size_t i; |
| 1398 char *env_preload=0; |
| 1399 size_t vdso_base; |
| 1400 int argc = *sp; |
| 1401 char **argv = (void *)(sp+1); |
| 1402 char **argv_orig = argv; |
| 1403 char **envp = argv+argc+1; |
| 1404 |
| 1405 /* Find aux vector just past environ[] and use it to initialize |
| 1406 * global data that may be needed before we can make syscalls. */ |
| 1407 __environ = envp; |
| 1408 for (i=argc+1; argv[i]; i++); |
| 1409 libc.auxv = auxv = (void *)(argv+i+1); |
| 1410 decode_vec(auxv, aux, AUX_CNT); |
| 1411 __hwcap = aux[AT_HWCAP]; |
| 1412 libc.page_size = aux[AT_PAGESZ]; |
| 1413 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID] |
| 1414 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]); |
| 1415 |
| 1416 /* Setup early thread pointer in builtin_tls for ldso/libc itself to |
| 1417 * use during dynamic linking. If possible it will also serve as the |
| 1418 * thread pointer at runtime. */ |
| 1419 libc.tls_size = sizeof builtin_tls; |
| 1420 libc.tls_align = tls_align; |
| 1421 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) { |
| 1422 a_crash(); |
| 1423 } |
| 1424 |
| 1425 /* Only trust user/env if kernel says we're not suid/sgid */ |
| 1426 if (!libc.secure) { |
| 1427 env_path = getenv("LD_LIBRARY_PATH"); |
| 1428 env_preload = getenv("LD_PRELOAD"); |
| 1429 } |
| 1430 |
| 1431 /* If the main program was already loaded by the kernel, |
| 1432 * AT_PHDR will point to some location other than the dynamic |
| 1433 * linker's program headers. */ |
| 1434 if (aux[AT_PHDR] != (size_t)ldso.phdr) { |
| 1435 size_t interp_off = 0; |
| 1436 size_t tls_image = 0; |
| 1437 /* Find load address of the main program, via AT_PHDR vs PT_PHDR
. */ |
| 1438 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR]; |
| 1439 app.phnum = aux[AT_PHNUM]; |
| 1440 app.phentsize = aux[AT_PHENT]; |
| 1441 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[A
T_PHENT])) { |
| 1442 if (phdr->p_type == PT_PHDR) |
| 1443 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr
); |
| 1444 else if (phdr->p_type == PT_INTERP) |
| 1445 interp_off = (size_t)phdr->p_vaddr; |
| 1446 else if (phdr->p_type == PT_TLS) { |
| 1447 tls_image = phdr->p_vaddr; |
| 1448 app.tls.len = phdr->p_filesz; |
| 1449 app.tls.size = phdr->p_memsz; |
| 1450 app.tls.align = phdr->p_align; |
| 1451 } |
| 1452 } |
| 1453 if (DL_FDPIC) app.loadmap = app_loadmap; |
| 1454 if (app.tls.size) app.tls.image = laddr(&app, tls_image); |
| 1455 if (interp_off) ldso.name = laddr(&app, interp_off); |
| 1456 if ((aux[0] & (1UL<<AT_EXECFN)) |
| 1457 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6)) |
| 1458 app.name = (char *)aux[AT_EXECFN]; |
| 1459 else |
| 1460 app.name = argv[0]; |
| 1461 kernel_mapped_dso(&app); |
| 1462 } else { |
| 1463 int fd; |
| 1464 char *ldname = argv[0]; |
| 1465 size_t l = strlen(ldname); |
| 1466 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1; |
| 1467 argv++; |
| 1468 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') { |
| 1469 char *opt = argv[0]+2; |
| 1470 *argv++ = (void *)-1; |
| 1471 if (!*opt) { |
| 1472 break; |
| 1473 } else if (!memcmp(opt, "list", 5)) { |
| 1474 ldd_mode = 1; |
| 1475 } else if (!memcmp(opt, "library-path", 12)) { |
| 1476 if (opt[12]=='=') env_path = opt+13; |
| 1477 else if (opt[12]) *argv = 0; |
| 1478 else if (*argv) env_path = *argv++; |
| 1479 } else if (!memcmp(opt, "preload", 7)) { |
| 1480 if (opt[7]=='=') env_preload = opt+8; |
| 1481 else if (opt[7]) *argv = 0; |
| 1482 else if (*argv) env_preload = *argv++; |
| 1483 } else { |
| 1484 argv[0] = 0; |
| 1485 } |
| 1486 } |
| 1487 argv[-1] = (void *)(argc - (argv-argv_orig)); |
| 1488 if (!argv[0]) { |
| 1489 dprintf(2, "musl libc\n" |
| 1490 "Version %s\n" |
| 1491 "Dynamic Program Loader\n" |
| 1492 "Usage: %s [options] [--] pathname%s\n", |
| 1493 __libc_get_version(), ldname, |
| 1494 ldd_mode ? "" : " [args]"); |
| 1495 _exit(1); |
| 1496 } |
| 1497 fd = open(argv[0], O_RDONLY); |
| 1498 if (fd < 0) { |
| 1499 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0],
strerror(errno)); |
| 1500 _exit(1); |
| 1501 } |
| 1502 runtime = 1; |
| 1503 Ehdr *ehdr = (void *)map_library(fd, &app); |
| 1504 if (!ehdr) { |
| 1505 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldna
me, argv[0]); |
| 1506 _exit(1); |
| 1507 } |
| 1508 runtime = 0; |
| 1509 close(fd); |
| 1510 ldso.name = ldname; |
| 1511 app.name = argv[0]; |
| 1512 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry); |
| 1513 /* Find the name that would have been used for the dynamic |
| 1514 * linker had ldd not taken its place. */ |
| 1515 if (ldd_mode) { |
| 1516 for (i=0; i<app.phnum; i++) { |
| 1517 if (app.phdr[i].p_type == PT_INTERP) |
| 1518 ldso.name = laddr(&app, app.phdr[i].p_va
ddr); |
| 1519 } |
| 1520 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base); |
| 1521 } |
| 1522 } |
| 1523 if (app.tls.size) { |
| 1524 libc.tls_head = &app.tls; |
| 1525 app.tls_id = tls_cnt = 1; |
| 1526 #ifdef TLS_ABOVE_TP |
| 1527 app.tls.offset = 0; |
| 1528 tls_offset = app.tls.size |
| 1529 + ( -((uintptr_t)app.tls.image + app.tls.size) |
| 1530 & (app.tls.align-1) ); |
| 1531 #else |
| 1532 tls_offset = app.tls.offset = app.tls.size |
| 1533 + ( -((uintptr_t)app.tls.image + app.tls.size) |
| 1534 & (app.tls.align-1) ); |
| 1535 #endif |
| 1536 tls_align = MAXP2(tls_align, app.tls.align); |
| 1537 } |
| 1538 app.global = 1; |
| 1539 decode_dyn(&app); |
| 1540 if (DL_FDPIC) { |
| 1541 makefuncdescs(&app); |
| 1542 if (!app.loadmap) { |
| 1543 app.loadmap = (void *)&app_dummy_loadmap; |
| 1544 app.loadmap->nsegs = 1; |
| 1545 app.loadmap->segs[0].addr = (size_t)app.map; |
| 1546 app.loadmap->segs[0].p_vaddr = (size_t)app.map |
| 1547 - (size_t)app.base; |
| 1548 app.loadmap->segs[0].p_memsz = app.map_len; |
| 1549 } |
| 1550 argv[-3] = (void *)app.loadmap; |
| 1551 } |
| 1552 |
| 1553 /* Attach to vdso, if provided by the kernel */ |
| 1554 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) { |
| 1555 Ehdr *ehdr = (void *)vdso_base; |
| 1556 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff); |
| 1557 vdso.phnum = ehdr->e_phnum; |
| 1558 vdso.phentsize = ehdr->e_phentsize; |
| 1559 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr-
>e_phentsize)) { |
| 1560 if (phdr->p_type == PT_DYNAMIC) |
| 1561 vdso.dynv = (void *)(vdso_base + phdr->p_offset)
; |
| 1562 if (phdr->p_type == PT_LOAD) |
| 1563 vdso.base = (void *)(vdso_base - phdr->p_vaddr +
phdr->p_offset); |
| 1564 } |
| 1565 vdso.name = ""; |
| 1566 vdso.shortname = "linux-gate.so.1"; |
| 1567 vdso.global = 1; |
| 1568 vdso.relocated = 1; |
| 1569 decode_dyn(&vdso); |
| 1570 vdso.prev = &ldso; |
| 1571 ldso.next = &vdso; |
| 1572 } |
| 1573 |
| 1574 /* Initial dso chain consists only of the app. */ |
| 1575 head = tail = &app; |
| 1576 |
| 1577 /* Donate unused parts of app and library mapping to malloc */ |
| 1578 reclaim_gaps(&app); |
| 1579 reclaim_gaps(&ldso); |
| 1580 |
| 1581 /* Load preload/needed libraries, add their symbols to the global |
| 1582 * namespace, and perform all remaining relocations. */ |
| 1583 if (env_preload) load_preload(env_preload); |
| 1584 load_deps(&app); |
| 1585 make_global(&app); |
| 1586 |
| 1587 #ifndef DYNAMIC_IS_RO |
| 1588 for (i=0; app.dynv[i]; i+=2) |
| 1589 if (app.dynv[i]==DT_DEBUG) |
| 1590 app.dynv[i+1] = (size_t)&debug; |
| 1591 #endif |
| 1592 |
| 1593 /* The main program must be relocated LAST since it may contin |
| 1594 * copy relocations which depend on libraries' relocations. */ |
| 1595 reloc_all(app.next); |
| 1596 reloc_all(&app); |
| 1597 |
| 1598 update_tls_size(); |
| 1599 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) { |
| 1600 void *initial_tls = calloc(libc.tls_size, 1); |
| 1601 if (!initial_tls) { |
| 1602 dprintf(2, "%s: Error getting %zu bytes thread-local sto
rage: %m\n", |
| 1603 argv[0], libc.tls_size); |
| 1604 _exit(127); |
| 1605 } |
| 1606 if (__init_tp(__copy_tls(initial_tls)) < 0) { |
| 1607 a_crash(); |
| 1608 } |
| 1609 } else { |
| 1610 size_t tmp_tls_size = libc.tls_size; |
| 1611 pthread_t self = __pthread_self(); |
| 1612 /* Temporarily set the tls size to the full size of |
| 1613 * builtin_tls so that __copy_tls will use the same layout |
| 1614 * as it did for before. Then check, just to be safe. */ |
| 1615 libc.tls_size = sizeof builtin_tls; |
| 1616 if (__copy_tls((void*)builtin_tls) != self) a_crash(); |
| 1617 libc.tls_size = tmp_tls_size; |
| 1618 } |
| 1619 static_tls_cnt = tls_cnt; |
| 1620 |
| 1621 if (ldso_fail) _exit(127); |
| 1622 if (ldd_mode) _exit(0); |
| 1623 |
| 1624 /* Switch to runtime mode: any further failures in the dynamic |
| 1625 * linker are a reportable failure rather than a fatal startup |
| 1626 * error. */ |
| 1627 runtime = 1; |
| 1628 |
| 1629 debug.ver = 1; |
| 1630 debug.bp = dl_debug_state; |
| 1631 debug.head = head; |
| 1632 debug.base = ldso.base; |
| 1633 debug.state = 0; |
| 1634 _dl_debug_state(); |
| 1635 |
| 1636 errno = 0; |
| 1637 |
| 1638 CRTJMP((void *)aux[AT_ENTRY], argv-1); |
| 1639 for(;;); |
| 1640 } |
| 1641 |
| 1642 void *dlopen(const char *file, int mode) |
| 1643 { |
| 1644 struct dso *volatile p, *orig_tail, *next; |
| 1645 struct tls_module *orig_tls_tail; |
| 1646 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align; |
| 1647 size_t i; |
| 1648 int cs; |
| 1649 jmp_buf jb; |
| 1650 |
| 1651 if (!file) return head; |
| 1652 |
| 1653 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); |
| 1654 pthread_rwlock_wrlock(&lock); |
| 1655 __inhibit_ptc(); |
| 1656 |
| 1657 p = 0; |
| 1658 orig_tls_tail = tls_tail; |
| 1659 orig_tls_cnt = tls_cnt; |
| 1660 orig_tls_offset = tls_offset; |
| 1661 orig_tls_align = tls_align; |
| 1662 orig_tail = tail; |
| 1663 noload = mode & RTLD_NOLOAD; |
| 1664 |
| 1665 rtld_fail = &jb; |
| 1666 if (setjmp(*rtld_fail)) { |
| 1667 /* Clean up anything new that was (partially) loaded */ |
| 1668 if (p && p->deps) for (i=0; p->deps[i]; i++) |
| 1669 if (p->deps[i]->global < 0) |
| 1670 p->deps[i]->global = 0; |
| 1671 for (p=orig_tail->next; p; p=next) { |
| 1672 next = p->next; |
| 1673 while (p->td_index) { |
| 1674 void *tmp = p->td_index->next; |
| 1675 free(p->td_index); |
| 1676 p->td_index = tmp; |
| 1677 } |
| 1678 free(p->funcdescs); |
| 1679 if (p->rpath != p->rpath_orig) |
| 1680 free(p->rpath); |
| 1681 free(p->deps); |
| 1682 unmap_library(p); |
| 1683 free(p); |
| 1684 } |
| 1685 if (!orig_tls_tail) libc.tls_head = 0; |
| 1686 tls_tail = orig_tls_tail; |
| 1687 tls_cnt = orig_tls_cnt; |
| 1688 tls_offset = orig_tls_offset; |
| 1689 tls_align = orig_tls_align; |
| 1690 tail = orig_tail; |
| 1691 tail->next = 0; |
| 1692 p = 0; |
| 1693 goto end; |
| 1694 } else p = load_library(file, head); |
| 1695 |
| 1696 if (!p) { |
| 1697 error(noload ? |
| 1698 "Library %s is not already loaded" : |
| 1699 "Error loading shared library %s: %m", |
| 1700 file); |
| 1701 goto end; |
| 1702 } |
| 1703 |
| 1704 /* First load handling */ |
| 1705 if (!p->deps) { |
| 1706 load_deps(p); |
| 1707 if (p->deps) for (i=0; p->deps[i]; i++) |
| 1708 if (!p->deps[i]->global) |
| 1709 p->deps[i]->global = -1; |
| 1710 if (!p->global) p->global = -1; |
| 1711 reloc_all(p); |
| 1712 if (p->deps) for (i=0; p->deps[i]; i++) |
| 1713 if (p->deps[i]->global < 0) |
| 1714 p->deps[i]->global = 0; |
| 1715 if (p->global < 0) p->global = 0; |
| 1716 } |
| 1717 |
| 1718 if (mode & RTLD_GLOBAL) { |
| 1719 if (p->deps) for (i=0; p->deps[i]; i++) |
| 1720 p->deps[i]->global = 1; |
| 1721 p->global = 1; |
| 1722 } |
| 1723 |
| 1724 update_tls_size(); |
| 1725 _dl_debug_state(); |
| 1726 orig_tail = tail; |
| 1727 end: |
| 1728 __release_ptc(); |
| 1729 if (p) gencnt++; |
| 1730 pthread_rwlock_unlock(&lock); |
| 1731 if (p) do_init_fini(orig_tail); |
| 1732 pthread_setcancelstate(cs, 0); |
| 1733 return p; |
| 1734 } |
| 1735 |
| 1736 static int invalid_dso_handle(void *h) |
| 1737 { |
| 1738 struct dso *p; |
| 1739 for (p=head; p; p=p->next) if (h==p) return 0; |
| 1740 error("Invalid library handle %p", (void *)h); |
| 1741 return 1; |
| 1742 } |
| 1743 |
| 1744 static void *addr2dso(size_t a) |
| 1745 { |
| 1746 struct dso *p; |
| 1747 size_t i; |
| 1748 if (DL_FDPIC) for (p=head; p; p=p->next) { |
| 1749 i = count_syms(p); |
| 1750 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs)) |
| 1751 return p; |
| 1752 } |
| 1753 for (p=head; p; p=p->next) { |
| 1754 if (DL_FDPIC && p->loadmap) { |
| 1755 for (i=0; i<p->loadmap->nsegs; i++) { |
| 1756 if (a-p->loadmap->segs[i].p_vaddr |
| 1757 < p->loadmap->segs[i].p_memsz) |
| 1758 return p; |
| 1759 } |
| 1760 } else { |
| 1761 if (a-(size_t)p->map < p->map_len) |
| 1762 return p; |
| 1763 } |
| 1764 } |
| 1765 return 0; |
| 1766 } |
| 1767 |
| 1768 void *__tls_get_addr(size_t *); |
| 1769 |
| 1770 static void *do_dlsym(struct dso *p, const char *s, void *ra) |
| 1771 { |
| 1772 size_t i; |
| 1773 uint32_t h = 0, gh = 0, *ght; |
| 1774 Sym *sym; |
| 1775 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) { |
| 1776 if (p == RTLD_DEFAULT) { |
| 1777 p = head; |
| 1778 } else if (p == RTLD_NEXT) { |
| 1779 p = addr2dso((size_t)ra); |
| 1780 if (!p) p=head; |
| 1781 p = p->next; |
| 1782 } |
| 1783 struct symdef def = find_sym(p, s, 0); |
| 1784 if (!def.sym) goto failed; |
| 1785 if ((def.sym->st_info&0xf) == STT_TLS) |
| 1786 return __tls_get_addr((size_t []){def.dso->tls_id, def.s
ym->st_value}); |
| 1787 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC) |
| 1788 return def.dso->funcdescs + (def.sym - def.dso->syms); |
| 1789 return laddr(def.dso, def.sym->st_value); |
| 1790 } |
| 1791 if (invalid_dso_handle(p)) |
| 1792 return 0; |
| 1793 if ((ght = p->ghashtab)) { |
| 1794 gh = gnu_hash(s); |
| 1795 sym = gnu_lookup(gh, ght, p, s); |
| 1796 } else { |
| 1797 h = sysv_hash(s); |
| 1798 sym = sysv_lookup(s, h, p); |
| 1799 } |
| 1800 if (sym && (sym->st_info&0xf) == STT_TLS) |
| 1801 return __tls_get_addr((size_t []){p->tls_id, sym->st_value}); |
| 1802 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC) |
| 1803 return p->funcdescs + (sym - p->syms); |
| 1804 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) |
| 1805 return laddr(p, sym->st_value); |
| 1806 if (p->deps) for (i=0; p->deps[i]; i++) { |
| 1807 if ((ght = p->deps[i]->ghashtab)) { |
| 1808 if (!gh) gh = gnu_hash(s); |
| 1809 sym = gnu_lookup(gh, ght, p->deps[i], s); |
| 1810 } else { |
| 1811 if (!h) h = sysv_hash(s); |
| 1812 sym = sysv_lookup(s, h, p->deps[i]); |
| 1813 } |
| 1814 if (sym && (sym->st_info&0xf) == STT_TLS) |
| 1815 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sy
m->st_value}); |
| 1816 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == ST
T_FUNC) |
| 1817 return p->deps[i]->funcdescs + (sym - p->deps[i]->syms); |
| 1818 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) |
| 1819 return laddr(p->deps[i], sym->st_value); |
| 1820 } |
| 1821 failed: |
| 1822 error("Symbol not found: %s", s); |
| 1823 return 0; |
| 1824 } |
| 1825 |
| 1826 int __dladdr(const void *addr, Dl_info *info) |
| 1827 { |
| 1828 struct dso *p; |
| 1829 Sym *sym, *bestsym; |
| 1830 uint32_t nsym; |
| 1831 char *strings; |
| 1832 void *best = 0; |
| 1833 |
| 1834 pthread_rwlock_rdlock(&lock); |
| 1835 p = addr2dso((size_t)addr); |
| 1836 pthread_rwlock_unlock(&lock); |
| 1837 |
| 1838 if (!p) return 0; |
| 1839 |
| 1840 sym = p->syms; |
| 1841 strings = p->strings; |
| 1842 nsym = count_syms(p); |
| 1843 |
| 1844 if (DL_FDPIC) { |
| 1845 size_t idx = ((size_t)addr-(size_t)p->funcdescs) |
| 1846 / sizeof(*p->funcdescs); |
| 1847 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) { |
| 1848 best = p->funcdescs + idx; |
| 1849 bestsym = sym + idx; |
| 1850 } |
| 1851 } |
| 1852 |
| 1853 if (!best) for (; nsym; nsym--, sym++) { |
| 1854 if (sym->st_value |
| 1855 && (1<<(sym->st_info&0xf) & OK_TYPES) |
| 1856 && (1<<(sym->st_info>>4) & OK_BINDS)) { |
| 1857 void *symaddr = laddr(p, sym->st_value); |
| 1858 if (symaddr > addr || symaddr < best) |
| 1859 continue; |
| 1860 best = symaddr; |
| 1861 bestsym = sym; |
| 1862 if (addr == symaddr) |
| 1863 break; |
| 1864 } |
| 1865 } |
| 1866 |
| 1867 if (!best) return 0; |
| 1868 |
| 1869 if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC) |
| 1870 best = p->funcdescs + (bestsym - p->syms); |
| 1871 |
| 1872 info->dli_fname = p->name; |
| 1873 info->dli_fbase = p->base; |
| 1874 info->dli_sname = strings + bestsym->st_name; |
| 1875 info->dli_saddr = best; |
| 1876 |
| 1877 return 1; |
| 1878 } |
| 1879 |
| 1880 __attribute__((__visibility__("hidden"))) |
| 1881 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) |
| 1882 { |
| 1883 void *res; |
| 1884 pthread_rwlock_rdlock(&lock); |
| 1885 res = do_dlsym(p, s, ra); |
| 1886 pthread_rwlock_unlock(&lock); |
| 1887 return res; |
| 1888 } |
| 1889 |
| 1890 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void
*data), void *data) |
| 1891 { |
| 1892 struct dso *current; |
| 1893 struct dl_phdr_info info; |
| 1894 int ret = 0; |
| 1895 for(current = head; current;) { |
| 1896 info.dlpi_addr = (uintptr_t)current->base; |
| 1897 info.dlpi_name = current->name; |
| 1898 info.dlpi_phdr = current->phdr; |
| 1899 info.dlpi_phnum = current->phnum; |
| 1900 info.dlpi_adds = gencnt; |
| 1901 info.dlpi_subs = 0; |
| 1902 info.dlpi_tls_modid = current->tls_id; |
| 1903 info.dlpi_tls_data = current->tls.image; |
| 1904 |
| 1905 ret = (callback)(&info, sizeof (info), data); |
| 1906 |
| 1907 if (ret != 0) break; |
| 1908 |
| 1909 pthread_rwlock_rdlock(&lock); |
| 1910 current = current->next; |
| 1911 pthread_rwlock_unlock(&lock); |
| 1912 } |
| 1913 return ret; |
| 1914 } |
| 1915 #else |
| 1916 static int invalid_dso_handle(void *h) |
| 1917 { |
| 1918 error("Invalid library handle %p", (void *)h); |
| 1919 return 1; |
| 1920 } |
| 1921 void *dlopen(const char *file, int mode) |
| 1922 { |
| 1923 error("Dynamic loading not supported"); |
| 1924 return 0; |
| 1925 } |
| 1926 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra) |
| 1927 { |
| 1928 error("Symbol not found: %s", s); |
| 1929 return 0; |
| 1930 } |
| 1931 int __dladdr (const void *addr, Dl_info *info) |
| 1932 { |
| 1933 return 0; |
| 1934 } |
| 1935 #endif |
| 1936 |
| 1937 int __dlinfo(void *dso, int req, void *res) |
| 1938 { |
| 1939 if (invalid_dso_handle(dso)) return -1; |
| 1940 if (req != RTLD_DI_LINKMAP) { |
| 1941 error("Unsupported request %d", req); |
| 1942 return -1; |
| 1943 } |
| 1944 *(struct link_map **)res = dso; |
| 1945 return 0; |
| 1946 } |
| 1947 |
| 1948 char *dlerror() |
| 1949 { |
| 1950 pthread_t self = __pthread_self(); |
| 1951 if (!self->dlerror_flag) return 0; |
| 1952 self->dlerror_flag = 0; |
| 1953 char *s = self->dlerror_buf; |
| 1954 if (s == (void *)-1) |
| 1955 return "Dynamic linker failed to allocate memory for error messa
ge"; |
| 1956 else |
| 1957 return s; |
| 1958 } |
| 1959 |
| 1960 int dlclose(void *p) |
| 1961 { |
| 1962 return invalid_dso_handle(p); |
| 1963 } |
| 1964 |
| 1965 void __dl_thread_cleanup(void) |
| 1966 { |
| 1967 pthread_t self = __pthread_self(); |
| 1968 if (self->dlerror_buf != (void *)-1) |
| 1969 free(self->dlerror_buf); |
| 1970 } |
| 1971 |
| 1972 static void error(const char *fmt, ...) |
| 1973 { |
| 1974 va_list ap; |
| 1975 va_start(ap, fmt); |
| 1976 #ifdef SHARED |
| 1977 if (!runtime) { |
| 1978 vdprintf(2, fmt, ap); |
| 1979 dprintf(2, "\n"); |
| 1980 ldso_fail = 1; |
| 1981 va_end(ap); |
| 1982 return; |
| 1983 } |
| 1984 #endif |
| 1985 pthread_t self = __pthread_self(); |
| 1986 if (self->dlerror_buf != (void *)-1) |
| 1987 free(self->dlerror_buf); |
| 1988 size_t len = vsnprintf(0, 0, fmt, ap); |
| 1989 va_end(ap); |
| 1990 char *buf = malloc(len+1); |
| 1991 if (buf) { |
| 1992 va_start(ap, fmt); |
| 1993 vsnprintf(buf, len+1, fmt, ap); |
| 1994 va_end(ap); |
| 1995 } else { |
| 1996 buf = (void *)-1; |
| 1997 } |
| 1998 self->dlerror_buf = buf; |
| 1999 self->dlerror_flag = 1; |
| 2000 } |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1573973002:
Add a "fork" of musl as //fusl. (Closed)
Base URL: https://github.com/domokit/mojo.git@master