nsz Git - musl/blob - ldso/dynlink.c

   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 #define MAXP2(a,b) (-(-(a)&-(b)))
  27 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  28
  29 struct debug {
  30         int ver;
  31         void *head;
  32         void (*bp)(void);
  33         int state;
  34         void *base;
  35 };
  36
  37 struct td_index {
  38         size_t args[2];
  39         struct td_index *next;
  40 };
  41
  42 struct dso {
  43 #if DL_FDPIC
  44         struct fdpic_loadmap *loadmap;
  45 #else
  46         unsigned char *base;
  47 #endif
  48         char *name;
  49         size_t *dynv;
  50         struct dso *next, *prev;
  51
  52         Phdr *phdr;
  53         int phnum;
  54         size_t phentsize;
  55         Sym *syms;
  56         Elf_Symndx *hashtab;
  57         uint32_t *ghashtab;
  58         int16_t *versym;
  59         char *strings;
  60         struct dso *syms_next, *lazy_next;
  61         size_t *lazy, lazy_cnt;
  62         unsigned char *map;
  63         size_t map_len;
  64         dev_t dev;
  65         ino_t ino;
  66         char relocated;
  67         char constructed;
  68         char kernel_mapped;
  69         struct dso **deps, *needed_by;
  70         char *rpath_orig, *rpath;
  71         struct tls_module tls;
  72         size_t tls_id;
  73         size_t relro_start, relro_end;
  74         void **new_dtv;
  75         unsigned char *new_tls;
  76         volatile int new_dtv_idx, new_tls_idx;
  77         struct td_index *td_index;
  78         struct dso *fini_next;
  79         char *shortname;
  80 #if DL_FDPIC
  81         unsigned char *base;
  82 #else
  83         struct fdpic_loadmap *loadmap;
  84 #endif
  85         struct funcdesc {
  86                 void *addr;
  87                 size_t *got;
  88         } *funcdescs;
  89         size_t *got;
  90         char buf[];
  91 };
  92
  93 struct symdef {
  94         Sym *sym;
  95         struct dso *dso;
  96 };
  97
  98 int __init_tp(void *);
  99 void __init_libc(char **, char *);
 100 void *__copy_tls(unsigned char *);
 101
 102 __attribute__((__visibility__("hidden")))
 103 const char *__libc_get_version(void);
 104
 105 static struct builtin_tls {
 106         char c;
 107         struct pthread pt;
 108         void *space[16];
 109 } builtin_tls[1];
 110 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 111
 112 #define ADDEND_LIMIT 4096
 113 static size_t *saved_addends, *apply_addends_to;
 114
 115 static struct dso ldso;
 116 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
 117 static char *env_path, *sys_path;
 118 static unsigned long long gencnt;
 119 static int runtime;
 120 static int ldd_mode;
 121 static int ldso_fail;
 122 static int noload;
 123 static jmp_buf *rtld_fail;
 124 static pthread_rwlock_t lock;
 125 static struct debug debug;
 126 static struct tls_module *tls_tail;
 127 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
 128 static size_t static_tls_cnt;
 129 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 130 static struct fdpic_loadmap *app_loadmap;
 131 static struct fdpic_dummy_loadmap app_dummy_loadmap;
 132
 133 struct debug *_dl_debug_addr = &debug;
 134
 135 __attribute__((__visibility__("hidden")))
 136 void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
 137
 138 __attribute__((__visibility__("hidden")))
 139 extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
 140
 141 weak_alias(__init_array_start, __init_array_end);
 142 weak_alias(__fini_array_start, __fini_array_end);
 143
 144 static int dl_strcmp(const char *l, const char *r)
 145 {
 146         for (; *l==*r && *l; l++, r++);
 147         return *(unsigned char *)l - *(unsigned char *)r;
 148 }
 149 #define strcmp(l,r) dl_strcmp(l,r)
 150
 151 /* Compute load address for a virtual address in a given dso. */
 152 #if DL_FDPIC
 153 static void *laddr(const struct dso *p, size_t v)
 154 {
 155         size_t j=0;
 156         if (!p->loadmap) return p->base + v;
 157         for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
 158         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 159 }
 160 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
 161         laddr(p, v), (p)->got })
 162 #else
 163 #define laddr(p, v) (void *)((p)->base + (v))
 164 #define fpaddr(p, v) ((void (*)())laddr(p, v))
 165 #endif
 166
 167 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 168 {
 169         size_t i;
 170         for (i=0; i<cnt; i++) a[i] = 0;
 171         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 172                 a[0] |= 1UL<<v[0];
 173                 a[v[0]] = v[1];
 174         }
 175 }
 176
 177 static int search_vec(size_t *v, size_t *r, size_t key)
 178 {
 179         for (; v[0]!=key; v+=2)
 180                 if (!v[0]) return 0;
 181         *r = v[1];
 182         return 1;
 183 }
 184
 185 static uint32_t sysv_hash(const char *s0)
 186 {
 187         const unsigned char *s = (void *)s0;
 188         uint_fast32_t h = 0;
 189         while (*s) {
 190                 h = 16*h + *s++;
 191                 h ^= h>>24 & 0xf0;
 192         }
 193         return h & 0xfffffff;
 194 }
 195
 196 static uint32_t gnu_hash(const char *s0)
 197 {
 198         const unsigned char *s = (void *)s0;
 199         uint_fast32_t h = 5381;
 200         for (; *s; s++)
 201                 h += h*32 + *s;
 202         return h;
 203 }
 204
 205 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 206 {
 207         size_t i;
 208         Sym *syms = dso->syms;
 209         Elf_Symndx *hashtab = dso->hashtab;
 210         char *strings = dso->strings;
 211         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 212                 if ((!dso->versym || dso->versym[i] >= 0)
 213                     && (!strcmp(s, strings+syms[i].st_name)))
 214                         return syms+i;
 215         }
 216         return 0;
 217 }
 218
 219 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 220 {
 221         uint32_t nbuckets = hashtab[0];
 222         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 223         uint32_t i = buckets[h1 % nbuckets];
 224
 225         if (!i) return 0;
 226
 227         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 228
 229         for (h1 |= 1; ; i++) {
 230                 uint32_t h2 = *hashval++;
 231                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 232                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 233                         return dso->syms+i;
 234                 if (h2 & 1) break;
 235         }
 236
 237         return 0;
 238 }
 239
 240 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 241 {
 242         const size_t *bloomwords = (const void *)(hashtab+4);
 243         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 244         if (!(f & fmask)) return 0;
 245
 246         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 247         if (!(f & 1)) return 0;
 248
 249         return gnu_lookup(h1, hashtab, dso, s);
 250 }
 251
 252 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 253 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 254
 255 #ifndef ARCH_SYM_REJECT_UND
 256 #define ARCH_SYM_REJECT_UND(s) 0
 257 #endif
 258
 259 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 260 {
 261         uint32_t h = 0, gh, gho, *ght;
 262         size_t ghm = 0;
 263         struct symdef def = {0};
 264         for (; dso; dso=dso->syms_next) {
 265                 Sym *sym;
 266                 if ((ght = dso->ghashtab)) {
 267                         if (!ghm) {
 268                                 gh = gnu_hash(s);
 269                                 int maskbits = 8 * sizeof ghm;
 270                                 gho = gh / maskbits;
 271                                 ghm = 1ul << gh % maskbits;
 272                         }
 273                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 274                 } else {
 275                         if (!h) h = sysv_hash(s);
 276                         sym = sysv_lookup(s, h, dso);
 277                 }
 278                 if (!sym) continue;
 279                 if (!sym->st_shndx)
 280                         if (need_def || (sym->st_info&0xf) == STT_TLS
 281                             || ARCH_SYM_REJECT_UND(sym))
 282                                 continue;
 283                 if (!sym->st_value)
 284                         if ((sym->st_info&0xf) != STT_TLS)
 285                                 continue;
 286                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 287                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 288                 def.sym = sym;
 289                 def.dso = dso;
 290                 break;
 291         }
 292         return def;
 293 }
 294
 295 __attribute__((__visibility__("hidden")))
 296 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 297
 298 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 299 {
 300         unsigned char *base = dso->base;
 301         Sym *syms = dso->syms;
 302         char *strings = dso->strings;
 303         Sym *sym;
 304         const char *name;
 305         void *ctx;
 306         int type;
 307         int sym_index;
 308         struct symdef def;
 309         size_t *reloc_addr;
 310         size_t sym_val;
 311         size_t tls_val;
 312         size_t addend;
 313         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 314
 315         if (dso == &ldso) {
 316                 /* Only ldso's REL table needs addend saving/reuse. */
 317                 if (rel == apply_addends_to)
 318                         reuse_addends = 1;
 319                 skip_relative = 1;
 320         }
 321
 322         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 323                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 324                 type = R_TYPE(rel[1]);
 325                 if (type == REL_NONE) continue;
 326                 reloc_addr = laddr(dso, rel[0]);
 327
 328                 if (stride > 2) {
 329                         addend = rel[2];
 330                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 331                         addend = 0;
 332                 } else if (reuse_addends) {
 333                         /* Save original addend in stage 2 where the dso
 334                          * chain consists of just ldso; otherwise read back
 335                          * saved addend since the inline one was clobbered. */
 336                         if (head==&ldso)
 337                                 saved_addends[save_slot] = *reloc_addr;
 338                         addend = saved_addends[save_slot++];
 339                 } else {
 340                         addend = *reloc_addr;
 341                 }
 342
 343                 sym_index = R_SYM(rel[1]);
 344                 if (sym_index) {
 345                         sym = syms + sym_index;
 346                         name = strings + sym->st_name;
 347                         ctx = type==REL_COPY ? head->syms_next : head;
 348                         def = (sym->st_info&0xf) == STT_SECTION
 349                                 ? (struct symdef){ .dso = dso, .sym = sym }
 350                                 : find_sym(ctx, name, type==REL_PLT);
 351                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 352                             || sym->st_info>>4 != STB_WEAK)) {
 353                                 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
 354                                         dso->lazy[3*dso->lazy_cnt+0] = rel[0];
 355                                         dso->lazy[3*dso->lazy_cnt+1] = rel[1];
 356                                         dso->lazy[3*dso->lazy_cnt+2] = addend;
 357                                         dso->lazy_cnt++;
 358                                         continue;
 359                                 }
 360                                 error("Error relocating %s: %s: symbol not found",
 361                                         dso->name, name);
 362                                 if (runtime) longjmp(*rtld_fail, 1);
 363                                 continue;
 364                         }
 365                 } else {
 366                         sym = 0;
 367                         def.sym = 0;
 368                         def.dso = dso;
 369                 }
 370
 371                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 372                 tls_val = def.sym ? def.sym->st_value : 0;
 373
 374                 switch(type) {
 375                 case REL_NONE:
 376                         break;
 377                 case REL_OFFSET:
 378                         addend -= (size_t)reloc_addr;
 379                 case REL_SYMBOLIC:
 380                 case REL_GOT:
 381                 case REL_PLT:
 382                         *reloc_addr = sym_val + addend;
 383                         break;
 384                 case REL_RELATIVE:
 385                         *reloc_addr = (size_t)base + addend;
 386                         break;
 387                 case REL_SYM_OR_REL:
 388                         if (sym) *reloc_addr = sym_val + addend;
 389                         else *reloc_addr = (size_t)base + addend;
 390                         break;
 391                 case REL_COPY:
 392                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 393                         break;
 394                 case REL_OFFSET32:
 395                         *(uint32_t *)reloc_addr = sym_val + addend
 396                                 - (size_t)reloc_addr;
 397                         break;
 398                 case REL_FUNCDESC:
 399                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 400                                 + (def.sym - def.dso->syms)) : 0;
 401                         break;
 402                 case REL_FUNCDESC_VAL:
 403                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 404                         else *reloc_addr = sym_val;
 405                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 406                         break;
 407                 case REL_DTPMOD:
 408                         *reloc_addr = def.dso->tls_id;
 409                         break;
 410                 case REL_DTPOFF:
 411                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 412                         break;
 413 #ifdef TLS_ABOVE_TP
 414                 case REL_TPOFF:
 415                         *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
 416                         break;
 417 #else
 418                 case REL_TPOFF:
 419                         *reloc_addr = tls_val - def.dso->tls.offset + addend;
 420                         break;
 421                 case REL_TPOFF_NEG:
 422                         *reloc_addr = def.dso->tls.offset - tls_val + addend;
 423                         break;
 424 #endif
 425                 case REL_TLSDESC:
 426                         if (stride<3) addend = reloc_addr[1];
 427                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 428                                 struct td_index *new = malloc(sizeof *new);
 429                                 if (!new) {
 430                                         error(
 431                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 432                                         dso->name, sym ? name : "(local)" );
 433                                         longjmp(*rtld_fail, 1);
 434                                 }
 435                                 new->next = dso->td_index;
 436                                 dso->td_index = new;
 437                                 new->args[0] = def.dso->tls_id;
 438                                 new->args[1] = tls_val + addend;
 439                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 440                                 reloc_addr[1] = (size_t)new;
 441                         } else {
 442                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 443 #ifdef TLS_ABOVE_TP
 444                                 reloc_addr[1] = tls_val + def.dso->tls.offset
 445                                         + TPOFF_K + addend;
 446 #else
 447                                 reloc_addr[1] = tls_val - def.dso->tls.offset
 448                                         + addend;
 449 #endif
 450                         }
 451                         break;
 452                 default:
 453                         error("Error relocating %s: unsupported relocation type %d",
 454                                 dso->name, type);
 455                         if (runtime) longjmp(*rtld_fail, 1);
 456                         continue;
 457                 }
 458         }
 459 }
 460
 461 static void redo_lazy_relocs()
 462 {
 463         struct dso *p = lazy_head, *next;
 464         lazy_head = 0;
 465         for (; p; p=next) {
 466                 next = p->lazy_next;
 467                 size_t size = p->lazy_cnt*3*sizeof(size_t);
 468                 p->lazy_cnt = 0;
 469                 do_relocs(p, p->lazy, size, 3);
 470                 if (p->lazy_cnt) {
 471                         p->lazy_next = lazy_head;
 472                         lazy_head = p;
 473                 } else {
 474                         free(p->lazy);
 475                         p->lazy = 0;
 476                         p->lazy_next = 0;
 477                 }
 478         }
 479 }
 480
 481 /* A huge hack: to make up for the wastefulness of shared libraries
 482  * needing at least a page of dirty memory even if they have no global
 483  * data, we reclaim the gaps at the beginning and end of writable maps
 484  * and "donate" them to the heap by setting up minimal malloc
 485  * structures and then freeing them. */
 486
 487 static void reclaim(struct dso *dso, size_t start, size_t end)
 488 {
 489         size_t *a, *z;
 490         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 491         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 492         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 493         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 494         if (start>end || end-start < 4*sizeof(size_t)) return;
 495         a = laddr(dso, start);
 496         z = laddr(dso, end);
 497         a[-2] = 1;
 498         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 499         z[1] = 1;
 500         free(a);
 501 }
 502
 503 static void reclaim_gaps(struct dso *dso)
 504 {
 505         Phdr *ph = dso->phdr;
 506         size_t phcnt = dso->phnum;
 507
 508         if (DL_FDPIC) return; // FIXME
 509         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 510                 if (ph->p_type!=PT_LOAD) continue;
 511                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 512                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 513                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 514                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 515         }
 516 }
 517
 518 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 519 {
 520         static int no_map_fixed;
 521         char *q;
 522         if (!no_map_fixed) {
 523                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 524                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 525                         return q;
 526                 no_map_fixed = 1;
 527         }
 528         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 529         if (flags & MAP_ANONYMOUS) {
 530                 memset(p, 0, n);
 531                 return p;
 532         }
 533         ssize_t r;
 534         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 535         for (q=p; n; q+=r, off+=r, n-=r) {
 536                 r = read(fd, q, n);
 537                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 538                 if (!r) {
 539                         memset(q, 0, n);
 540                         break;
 541                 }
 542         }
 543         return p;
 544 }
 545
 546 static void unmap_library(struct dso *dso)
 547 {
 548         if (dso->loadmap) {
 549                 size_t i;
 550                 for (i=0; i<dso->loadmap->nsegs; i++) {
 551                         if (!dso->loadmap->segs[i].p_memsz)
 552                                 continue;
 553                         munmap((void *)dso->loadmap->segs[i].addr,
 554                                 dso->loadmap->segs[i].p_memsz);
 555                 }
 556                 free(dso->loadmap);
 557         } else if (dso->map && dso->map_len) {
 558                 munmap(dso->map, dso->map_len);
 559         }
 560 }
 561
 562 static void *map_library(int fd, struct dso *dso)
 563 {
 564         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 565         void *allocated_buf=0;
 566         size_t phsize;
 567         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 568         size_t this_min, this_max;
 569         size_t nsegs = 0;
 570         off_t off_start;
 571         Ehdr *eh;
 572         Phdr *ph, *ph0;
 573         unsigned prot;
 574         unsigned char *map=MAP_FAILED, *base;
 575         size_t dyn=0;
 576         size_t tls_image=0;
 577         size_t i;
 578
 579         ssize_t l = read(fd, buf, sizeof buf);
 580         eh = buf;
 581         if (l<0) return 0;
 582         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 583                 goto noexec;
 584         phsize = eh->e_phentsize * eh->e_phnum;
 585         if (phsize > sizeof buf - sizeof *eh) {
 586                 allocated_buf = malloc(phsize);
 587                 if (!allocated_buf) return 0;
 588                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 589                 if (l < 0) goto error;
 590                 if (l != phsize) goto noexec;
 591                 ph = ph0 = allocated_buf;
 592         } else if (eh->e_phoff + phsize > l) {
 593                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 594                 if (l < 0) goto error;
 595                 if (l != phsize) goto noexec;
 596                 ph = ph0 = (void *)(buf + 1);
 597         } else {
 598                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 599         }
 600         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 601                 if (ph->p_type == PT_DYNAMIC) {
 602                         dyn = ph->p_vaddr;
 603                 } else if (ph->p_type == PT_TLS) {
 604                         tls_image = ph->p_vaddr;
 605                         dso->tls.align = ph->p_align;
 606                         dso->tls.len = ph->p_filesz;
 607                         dso->tls.size = ph->p_memsz;
 608                 } else if (ph->p_type == PT_GNU_RELRO) {
 609                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 610                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 611                 }
 612                 if (ph->p_type != PT_LOAD) continue;
 613                 nsegs++;
 614                 if (ph->p_vaddr < addr_min) {
 615                         addr_min = ph->p_vaddr;
 616                         off_start = ph->p_offset;
 617                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 618                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 619                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 620                 }
 621                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 622                         addr_max = ph->p_vaddr+ph->p_memsz;
 623                 }
 624         }
 625         if (!dyn) goto noexec;
 626         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 627                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 628                         + nsegs * sizeof *dso->loadmap->segs);
 629                 if (!dso->loadmap) goto error;
 630                 dso->loadmap->nsegs = nsegs;
 631                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 632                         if (ph->p_type != PT_LOAD) continue;
 633                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 634                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 635                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 636                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 637                                 prot, MAP_PRIVATE,
 638                                 fd, ph->p_offset & -PAGE_SIZE);
 639                         if (map == MAP_FAILED) {
 640                                 unmap_library(dso);
 641                                 goto error;
 642                         }
 643                         dso->loadmap->segs[i].addr = (size_t)map +
 644                                 (ph->p_vaddr & PAGE_SIZE-1);
 645                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 646                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 647                         i++;
 648                         if (prot & PROT_WRITE) {
 649                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 650                                         + ph->p_filesz;
 651                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 652                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 653                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 654                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 655                                         pgend-pgbrk, prot,
 656                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 657                                         -1, off_start) == MAP_FAILED)
 658                                         goto error;
 659                                 memset(map + brk, 0, pgbrk-brk);
 660                         }
 661                 }
 662                 map = (void *)dso->loadmap->segs[0].addr;
 663                 map_len = 0;
 664                 goto done_mapping;
 665         }
 666         addr_max += PAGE_SIZE-1;
 667         addr_max &= -PAGE_SIZE;
 668         addr_min &= -PAGE_SIZE;
 669         off_start &= -PAGE_SIZE;
 670         map_len = addr_max - addr_min + off_start;
 671         /* The first time, we map too much, possibly even more than
 672          * the length of the file. This is okay because we will not
 673          * use the invalid part; we just need to reserve the right
 674          * amount of virtual address space to map over later. */
 675         map = DL_NOMMU_SUPPORT
 676                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 677                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 678                 : mmap((void *)addr_min, map_len, prot,
 679                         MAP_PRIVATE, fd, off_start);
 680         if (map==MAP_FAILED) goto error;
 681         dso->map = map;
 682         dso->map_len = map_len;
 683         /* If the loaded file is not relocatable and the requested address is
 684          * not available, then the load operation must fail. */
 685         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 686                 errno = EBUSY;
 687                 goto error;
 688         }
 689         base = map - addr_min;
 690         dso->phdr = 0;
 691         dso->phnum = 0;
 692         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 693                 if (ph->p_type != PT_LOAD) continue;
 694                 /* Check if the programs headers are in this load segment, and
 695                  * if so, record the address for use by dl_iterate_phdr. */
 696                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 697                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 698                         dso->phdr = (void *)(base + ph->p_vaddr
 699                                 + (eh->e_phoff-ph->p_offset));
 700                         dso->phnum = eh->e_phnum;
 701                         dso->phentsize = eh->e_phentsize;
 702                 }
 703                 /* Reuse the existing mapping for the lowest-address LOAD */
 704                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
 705                         continue;
 706                 this_min = ph->p_vaddr & -PAGE_SIZE;
 707                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 708                 off_start = ph->p_offset & -PAGE_SIZE;
 709                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 710                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 711                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 712                 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 713                         goto error;
 714                 if (ph->p_memsz > ph->p_filesz) {
 715                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 716                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 717                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 718                         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)
 719                                 goto error;
 720                 }
 721         }
 722         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 723                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 724                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 725                             && errno != ENOSYS)
 726                                 goto error;
 727                         break;
 728                 }
 729 done_mapping:
 730         dso->base = base;
 731         dso->dynv = laddr(dso, dyn);
 732         if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
 733         if (!runtime) reclaim_gaps(dso);
 734         free(allocated_buf);
 735         return map;
 736 noexec:
 737         errno = ENOEXEC;
 738 error:
 739         if (map!=MAP_FAILED) unmap_library(dso);
 740         free(allocated_buf);
 741         return 0;
 742 }
 743
 744 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 745 {
 746         size_t l;
 747         int fd;
 748         for (;;) {
 749                 s += strspn(s, ":\n");
 750                 l = strcspn(s, ":\n");
 751                 if (l-1 >= INT_MAX) return -1;
 752                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 753                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 754                         switch (errno) {
 755                         case ENOENT:
 756                         case ENOTDIR:
 757                         case EACCES:
 758                         case ENAMETOOLONG:
 759                                 break;
 760                         default:
 761                                 /* Any negative value but -1 will inhibit
 762                                  * futher path search. */
 763                                 return -2;
 764                         }
 765                 }
 766                 s += l;
 767         }
 768 }
 769
 770 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 771 {
 772         size_t n, l;
 773         const char *s, *t, *origin;
 774         char *d;
 775         if (p->rpath || !p->rpath_orig) return 0;
 776         if (!strchr(p->rpath_orig, '$')) {
 777                 p->rpath = p->rpath_orig;
 778                 return 0;
 779         }
 780         n = 0;
 781         s = p->rpath_orig;
 782         while ((t=strchr(s, '$'))) {
 783                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 784                         return 0;
 785                 s = t+1;
 786                 n++;
 787         }
 788         if (n > SSIZE_MAX/PATH_MAX) return 0;
 789
 790         if (p->kernel_mapped) {
 791                 /* $ORIGIN searches cannot be performed for the main program
 792                  * when it is suid/sgid/AT_SECURE. This is because the
 793                  * pathname is under the control of the caller of execve.
 794                  * For libraries, however, $ORIGIN can be processed safely
 795                  * since the library's pathname came from a trusted source
 796                  * (either system paths or a call to dlopen). */
 797                 if (libc.secure)
 798                         return 0;
 799                 l = readlink("/proc/self/exe", buf, buf_size);
 800                 if (l == -1) switch (errno) {
 801                 case ENOENT:
 802                 case ENOTDIR:
 803                 case EACCES:
 804                         break;
 805                 default:
 806                         return -1;
 807                 }
 808                 if (l >= buf_size)
 809                         return 0;
 810                 buf[l] = 0;
 811                 origin = buf;
 812         } else {
 813                 origin = p->name;
 814         }
 815         t = strrchr(origin, '/');
 816         l = t ? t-origin : 0;
 817         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 818         if (!p->rpath) return -1;
 819
 820         d = p->rpath;
 821         s = p->rpath_orig;
 822         while ((t=strchr(s, '$'))) {
 823                 memcpy(d, s, t-s);
 824                 d += t-s;
 825                 memcpy(d, origin, l);
 826                 d += l;
 827                 /* It was determined previously that the '$' is followed
 828                  * either by "ORIGIN" or "{ORIGIN}". */
 829                 s = t + 7 + 2*(t[1]=='{');
 830         }
 831         strcpy(d, s);
 832         return 0;
 833 }
 834
 835 static void decode_dyn(struct dso *p)
 836 {
 837         size_t dyn[DYN_CNT];
 838         decode_vec(p->dynv, dyn, DYN_CNT);
 839         p->syms = laddr(p, dyn[DT_SYMTAB]);
 840         p->strings = laddr(p, dyn[DT_STRTAB]);
 841         if (dyn[0]&(1<<DT_HASH))
 842                 p->hashtab = laddr(p, dyn[DT_HASH]);
 843         if (dyn[0]&(1<<DT_RPATH))
 844                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 845         if (dyn[0]&(1<<DT_RUNPATH))
 846                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 847         if (dyn[0]&(1<<DT_PLTGOT))
 848                 p->got = laddr(p, dyn[DT_PLTGOT]);
 849         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 850                 p->ghashtab = laddr(p, *dyn);
 851         if (search_vec(p->dynv, dyn, DT_VERSYM))
 852                 p->versym = laddr(p, *dyn);
 853 }
 854
 855 static size_t count_syms(struct dso *p)
 856 {
 857         if (p->hashtab) return p->hashtab[1];
 858
 859         size_t nsym, i;
 860         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 861         uint32_t *hashval;
 862         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 863                 if (buckets[i] > nsym)
 864                         nsym = buckets[i];
 865         }
 866         if (nsym) {
 867                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 868                 do nsym++;
 869                 while (!(*hashval++ & 1));
 870         }
 871         return nsym;
 872 }
 873
 874 static void *dl_mmap(size_t n)
 875 {
 876         void *p;
 877         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 878 #ifdef SYS_mmap2
 879         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 880 #else
 881         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 882 #endif
 883         return p == MAP_FAILED ? 0 : p;
 884 }
 885
 886 static void makefuncdescs(struct dso *p)
 887 {
 888         static int self_done;
 889         size_t nsym = count_syms(p);
 890         size_t i, size = nsym * sizeof(*p->funcdescs);
 891
 892         if (!self_done) {
 893                 p->funcdescs = dl_mmap(size);
 894                 self_done = 1;
 895         } else {
 896                 p->funcdescs = malloc(size);
 897         }
 898         if (!p->funcdescs) {
 899                 if (!runtime) a_crash();
 900                 error("Error allocating function descriptors for %s", p->name);
 901                 longjmp(*rtld_fail, 1);
 902         }
 903         for (i=0; i<nsym; i++) {
 904                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 905                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 906                         p->funcdescs[i].got = p->got;
 907                 } else {
 908                         p->funcdescs[i].addr = 0;
 909                         p->funcdescs[i].got = 0;
 910                 }
 911         }
 912 }
 913
 914 static struct dso *load_library(const char *name, struct dso *needed_by)
 915 {
 916         char buf[2*NAME_MAX+2];
 917         const char *pathname;
 918         unsigned char *map;
 919         struct dso *p, temp_dso = {0};
 920         int fd;
 921         struct stat st;
 922         size_t alloc_size;
 923         int n_th = 0;
 924         int is_self = 0;
 925
 926         if (!*name) {
 927                 errno = EINVAL;
 928                 return 0;
 929         }
 930
 931         /* Catch and block attempts to reload the implementation itself */
 932         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 933                 static const char reserved[] =
 934                         "c.pthread.rt.m.dl.util.xnet.";
 935                 const char *rp, *next;
 936                 for (rp=reserved; *rp; rp=next) {
 937                         next = strchr(rp, '.') + 1;
 938                         if (strncmp(name+3, rp, next-rp) == 0)
 939                                 break;
 940                 }
 941                 if (*rp) {
 942                         if (ldd_mode) {
 943                                 /* Track which names have been resolved
 944                                  * and only report each one once. */
 945                                 static unsigned reported;
 946                                 unsigned mask = 1U<<(rp-reserved);
 947                                 if (!(reported & mask)) {
 948                                         reported |= mask;
 949                                         dprintf(1, "\t%s => %s (%p)\n",
 950                                                 name, ldso.name,
 951                                                 ldso.base);
 952                                 }
 953                         }
 954                         is_self = 1;
 955                 }
 956         }
 957         if (!strcmp(name, ldso.name)) is_self = 1;
 958         if (is_self) {
 959                 if (!ldso.prev) {
 960                         tail->next = &ldso;
 961                         ldso.prev = tail;
 962                         tail = &ldso;
 963                 }
 964                 return &ldso;
 965         }
 966         if (strchr(name, '/')) {
 967                 pathname = name;
 968                 fd = open(name, O_RDONLY|O_CLOEXEC);
 969         } else {
 970                 /* Search for the name to see if it's already loaded */
 971                 for (p=head->next; p; p=p->next) {
 972                         if (p->shortname && !strcmp(p->shortname, name)) {
 973                                 return p;
 974                         }
 975                 }
 976                 if (strlen(name) > NAME_MAX) return 0;
 977                 fd = -1;
 978                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 979                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 980                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 981                                 fd = -2; /* Inhibit further search. */
 982                         if (p->rpath)
 983                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 984                 }
 985                 if (fd == -1) {
 986                         if (!sys_path) {
 987                                 char *prefix = 0;
 988                                 size_t prefix_len;
 989                                 if (ldso.name[0]=='/') {
 990                                         char *s, *t, *z;
 991                                         for (s=t=z=ldso.name; *s; s++)
 992                                                 if (*s=='/') z=t, t=s;
 993                                         prefix_len = z-ldso.name;
 994                                         if (prefix_len < PATH_MAX)
 995                                                 prefix = ldso.name;
 996                                 }
 997                                 if (!prefix) {
 998                                         prefix = "";
 999                                         prefix_len = 0;
1000                                 }
1001                                 char etc_ldso_path[prefix_len + 1
1002                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1003                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1004                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1005                                         (int)prefix_len, prefix);
1006                                 FILE *f = fopen(etc_ldso_path, "rbe");
1007                                 if (f) {
1008                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1009                                                 free(sys_path);
1010                                                 sys_path = "";
1011                                         }
1012                                         fclose(f);
1013                                 } else if (errno != ENOENT) {
1014                                         sys_path = "";
1015                                 }
1016                         }
1017                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1018                         fd = path_open(name, sys_path, buf, sizeof buf);
1019                 }
1020                 pathname = buf;
1021         }
1022         if (fd < 0) return 0;
1023         if (fstat(fd, &st) < 0) {
1024                 close(fd);
1025                 return 0;
1026         }
1027         for (p=head->next; p; p=p->next) {
1028                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1029                         /* If this library was previously loaded with a
1030                          * pathname but a search found the same inode,
1031                          * setup its shortname so it can be found by name. */
1032                         if (!p->shortname && pathname != name)
1033                                 p->shortname = strrchr(p->name, '/')+1;
1034                         close(fd);
1035                         return p;
1036                 }
1037         }
1038         map = noload ? 0 : map_library(fd, &temp_dso);
1039         close(fd);
1040         if (!map) return 0;
1041
1042         /* Avoid the danger of getting two versions of libc mapped into the
1043          * same process when an absolute pathname was used. The symbols
1044          * checked are chosen to catch both musl and glibc, and to avoid
1045          * false positives from interposition-hack libraries. */
1046         decode_dyn(&temp_dso);
1047         if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1048             find_sym(&temp_dso, "stdin", 1).sym) {
1049                 unmap_library(&temp_dso);
1050                 return load_library("libc.so", needed_by);
1051         }
1052
1053         /* Allocate storage for the new DSO. When there is TLS, this
1054          * storage must include a reservation for all pre-existing
1055          * threads to obtain copies of both the new TLS, and an
1056          * extended DTV capable of storing an additional slot for
1057          * the newly-loaded DSO. */
1058         alloc_size = sizeof *p + strlen(pathname) + 1;
1059         if (runtime && temp_dso.tls.image) {
1060                 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1061                         + sizeof(void *) * (tls_cnt+3);
1062                 n_th = libc.threads_minus_1 + 1;
1063                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1064                 else alloc_size += n_th * per_th;
1065         }
1066         p = calloc(1, alloc_size);
1067         if (!p) {
1068                 unmap_library(&temp_dso);
1069                 return 0;
1070         }
1071         memcpy(p, &temp_dso, sizeof temp_dso);
1072         p->dev = st.st_dev;
1073         p->ino = st.st_ino;
1074         p->needed_by = needed_by;
1075         p->name = p->buf;
1076         strcpy(p->name, pathname);
1077         /* Add a shortname only if name arg was not an explicit pathname. */
1078         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1079         if (p->tls.image) {
1080                 p->tls_id = ++tls_cnt;
1081                 tls_align = MAXP2(tls_align, p->tls.align);
1082 #ifdef TLS_ABOVE_TP
1083                 p->tls.offset = tls_offset + ( (tls_align-1) &
1084                         -(tls_offset + (uintptr_t)p->tls.image) );
1085                 tls_offset += p->tls.size;
1086 #else
1087                 tls_offset += p->tls.size + p->tls.align - 1;
1088                 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1089                         & (p->tls.align-1);
1090                 p->tls.offset = tls_offset;
1091 #endif
1092                 p->new_dtv = (void *)(-sizeof(size_t) &
1093                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1094                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1095                 if (tls_tail) tls_tail->next = &p->tls;
1096                 else libc.tls_head = &p->tls;
1097                 tls_tail = &p->tls;
1098         }
1099
1100         tail->next = p;
1101         p->prev = tail;
1102         tail = p;
1103
1104         if (DL_FDPIC) makefuncdescs(p);
1105
1106         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1107
1108         return p;
1109 }
1110
1111 static void load_deps(struct dso *p)
1112 {
1113         size_t i, ndeps=0;
1114         struct dso ***deps = &p->deps, **tmp, *dep;
1115         for (; p; p=p->next) {
1116                 for (i=0; p->dynv[i]; i+=2) {
1117                         if (p->dynv[i] != DT_NEEDED) continue;
1118                         dep = load_library(p->strings + p->dynv[i+1], p);
1119                         if (!dep) {
1120                                 error("Error loading shared library %s: %m (needed by %s)",
1121                                         p->strings + p->dynv[i+1], p->name);
1122                                 if (runtime) longjmp(*rtld_fail, 1);
1123                                 continue;
1124                         }
1125                         if (runtime) {
1126                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1127                                 if (!tmp) longjmp(*rtld_fail, 1);
1128                                 tmp[ndeps++] = dep;
1129                                 tmp[ndeps] = 0;
1130                                 *deps = tmp;
1131                         }
1132                 }
1133         }
1134 }
1135
1136 static void load_preload(char *s)
1137 {
1138         int tmp;
1139         char *z;
1140         for (z=s; *z; s=z) {
1141                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1142                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1143                 tmp = *z;
1144                 *z = 0;
1145                 load_library(s, 0);
1146                 *z = tmp;
1147         }
1148 }
1149
1150 static void add_syms(struct dso *p)
1151 {
1152         if (!p->syms_next && syms_tail != p) {
1153                 syms_tail->syms_next = p;
1154                 syms_tail = p;
1155         }
1156 }
1157
1158 static void revert_syms(struct dso *old_tail)
1159 {
1160         struct dso *p, *next;
1161         /* Chop off the tail of the list of dsos that participate in
1162          * the global symbol table, reverting them to RTLD_LOCAL. */
1163         for (p=old_tail; p; p=next) {
1164                 next = p->syms_next;
1165                 p->syms_next = 0;
1166         }
1167         syms_tail = old_tail;
1168 }
1169
1170 static void do_mips_relocs(struct dso *p, size_t *got)
1171 {
1172         size_t i, j, rel[2];
1173         unsigned char *base = p->base;
1174         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1175         if (p==&ldso) {
1176                 got += i;
1177         } else {
1178                 while (i--) *got++ += (size_t)base;
1179         }
1180         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1181         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1182         Sym *sym = p->syms + j;
1183         rel[0] = (unsigned char *)got - base;
1184         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1185                 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1186                 do_relocs(p, rel, sizeof rel, 2);
1187         }
1188 }
1189
1190 static void reloc_all(struct dso *p)
1191 {
1192         size_t dyn[DYN_CNT];
1193         for (; p; p=p->next) {
1194                 if (p->relocated) continue;
1195                 decode_vec(p->dynv, dyn, DYN_CNT);
1196                 if (NEED_MIPS_GOT_RELOCS)
1197                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1198                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1199                         2+(dyn[DT_PLTREL]==DT_RELA));
1200                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1201                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1202
1203                 if (head != &ldso && p->relro_start != p->relro_end &&
1204                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1205                     && errno != ENOSYS) {
1206                         error("Error relocating %s: RELRO protection failed: %m",
1207                                 p->name);
1208                         if (runtime) longjmp(*rtld_fail, 1);
1209                 }
1210
1211                 p->relocated = 1;
1212         }
1213 }
1214
1215 static void kernel_mapped_dso(struct dso *p)
1216 {
1217         size_t min_addr = -1, max_addr = 0, cnt;
1218         Phdr *ph = p->phdr;
1219         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1220                 if (ph->p_type == PT_DYNAMIC) {
1221                         p->dynv = laddr(p, ph->p_vaddr);
1222                 } else if (ph->p_type == PT_GNU_RELRO) {
1223                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1224                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1225                 }
1226                 if (ph->p_type != PT_LOAD) continue;
1227                 if (ph->p_vaddr < min_addr)
1228                         min_addr = ph->p_vaddr;
1229                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1230                         max_addr = ph->p_vaddr+ph->p_memsz;
1231         }
1232         min_addr &= -PAGE_SIZE;
1233         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1234         p->map = p->base + min_addr;
1235         p->map_len = max_addr - min_addr;
1236         p->kernel_mapped = 1;
1237 }
1238
1239 void __libc_exit_fini()
1240 {
1241         struct dso *p;
1242         size_t dyn[DYN_CNT];
1243         for (p=fini_head; p; p=p->fini_next) {
1244                 if (!p->constructed) continue;
1245                 decode_vec(p->dynv, dyn, DYN_CNT);
1246                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1247                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1248                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1249                         while (n--) ((void (*)(void))*--fn)();
1250                 }
1251 #ifndef NO_LEGACY_INITFINI
1252                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1253                         fpaddr(p, dyn[DT_FINI])();
1254 #endif
1255         }
1256 }
1257
1258 static void do_init_fini(struct dso *p)
1259 {
1260         size_t dyn[DYN_CNT];
1261         int need_locking = libc.threads_minus_1;
1262         /* Allow recursive calls that arise when a library calls
1263          * dlopen from one of its constructors, but block any
1264          * other threads until all ctors have finished. */
1265         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1266         for (; p; p=p->prev) {
1267                 if (p->constructed) continue;
1268                 p->constructed = 1;
1269                 decode_vec(p->dynv, dyn, DYN_CNT);
1270                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1271                         p->fini_next = fini_head;
1272                         fini_head = p;
1273                 }
1274 #ifndef NO_LEGACY_INITFINI
1275                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1276                         fpaddr(p, dyn[DT_INIT])();
1277 #endif
1278                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1279                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1280                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1281                         while (n--) ((void (*)(void))*fn++)();
1282                 }
1283                 if (!need_locking && libc.threads_minus_1) {
1284                         need_locking = 1;
1285                         pthread_mutex_lock(&init_fini_lock);
1286                 }
1287         }
1288         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1289 }
1290
1291 void __libc_start_init(void)
1292 {
1293         do_init_fini(tail);
1294 }
1295
1296 static void dl_debug_state(void)
1297 {
1298 }
1299
1300 weak_alias(dl_debug_state, _dl_debug_state);
1301
1302 void __init_tls(size_t *auxv)
1303 {
1304 }
1305
1306 __attribute__((__visibility__("hidden")))
1307 void *__tls_get_new(tls_mod_off_t *v)
1308 {
1309         pthread_t self = __pthread_self();
1310
1311         /* Block signals to make accessing new TLS async-signal-safe */
1312         sigset_t set;
1313         __block_all_sigs(&set);
1314         if (v[0]<=(size_t)self->dtv[0]) {
1315                 __restore_sigs(&set);
1316                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1317         }
1318
1319         /* This is safe without any locks held because, if the caller
1320          * is able to request the Nth entry of the DTV, the DSO list
1321          * must be valid at least that far out and it was synchronized
1322          * at program startup or by an already-completed call to dlopen. */
1323         struct dso *p;
1324         for (p=head; p->tls_id != v[0]; p=p->next);
1325
1326         /* Get new DTV space from new DSO if needed */
1327         if (v[0] > (size_t)self->dtv[0]) {
1328                 void **newdtv = p->new_dtv +
1329                         (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1330                 memcpy(newdtv, self->dtv,
1331                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1332                 newdtv[0] = (void *)v[0];
1333                 self->dtv = self->dtv_copy = newdtv;
1334         }
1335
1336         /* Get new TLS memory from all new DSOs up to the requested one */
1337         unsigned char *mem;
1338         for (p=head; ; p=p->next) {
1339                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1340                 mem = p->new_tls + (p->tls.size + p->tls.align)
1341                         * a_fetch_add(&p->new_tls_idx,1);
1342                 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1343                         & (p->tls.align-1);
1344                 self->dtv[p->tls_id] = mem;
1345                 memcpy(mem, p->tls.image, p->tls.len);
1346                 if (p->tls_id == v[0]) break;
1347         }
1348         __restore_sigs(&set);
1349         return mem + v[1] + DTP_OFFSET;
1350 }
1351
1352 static void update_tls_size()
1353 {
1354         libc.tls_cnt = tls_cnt;
1355         libc.tls_align = tls_align;
1356         libc.tls_size = ALIGN(
1357                 (1+tls_cnt) * sizeof(void *) +
1358                 tls_offset +
1359                 sizeof(struct pthread) +
1360                 tls_align * 2,
1361         tls_align);
1362 }
1363
1364 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1365  * following stage 2 and stage 3 functions via primitive symbolic lookup
1366  * since it does not have access to their addresses to begin with. */
1367
1368 /* Stage 2 of the dynamic linker is called after relative relocations
1369  * have been processed. It can make function calls to static functions
1370  * and access string literals and static data, but cannot use extern
1371  * symbols. Its job is to perform symbolic relocations on the dynamic
1372  * linker itself, but some of the relocations performed may need to be
1373  * replaced later due to copy relocations in the main program. */
1374
1375 __attribute__((__visibility__("hidden")))
1376 void __dls2(unsigned char *base, size_t *sp)
1377 {
1378         if (DL_FDPIC) {
1379                 void *p1 = (void *)sp[-2];
1380                 void *p2 = (void *)sp[-1];
1381                 if (!p1) {
1382                         size_t *auxv, aux[AUX_CNT];
1383                         for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1384                         decode_vec(auxv, aux, AUX_CNT);
1385                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1386                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1387                 }
1388                 app_loadmap = p2 ? p1 : 0;
1389                 ldso.loadmap = p2 ? p2 : p1;
1390                 ldso.base = laddr(&ldso, 0);
1391         } else {
1392                 ldso.base = base;
1393         }
1394         Ehdr *ehdr = (void *)ldso.base;
1395         ldso.name = ldso.shortname = "libc.so";
1396         ldso.phnum = ehdr->e_phnum;
1397         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1398         ldso.phentsize = ehdr->e_phentsize;
1399         kernel_mapped_dso(&ldso);
1400         decode_dyn(&ldso);
1401
1402         if (DL_FDPIC) makefuncdescs(&ldso);
1403
1404         /* Prepare storage for to save clobbered REL addends so they
1405          * can be reused in stage 3. There should be very few. If
1406          * something goes wrong and there are a huge number, abort
1407          * instead of risking stack overflow. */
1408         size_t dyn[DYN_CNT];
1409         decode_vec(ldso.dynv, dyn, DYN_CNT);
1410         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1411         size_t rel_size = dyn[DT_RELSZ];
1412         size_t symbolic_rel_cnt = 0;
1413         apply_addends_to = rel;
1414         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1415                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1416         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1417         size_t addends[symbolic_rel_cnt+1];
1418         saved_addends = addends;
1419
1420         head = &ldso;
1421         reloc_all(&ldso);
1422
1423         ldso.relocated = 0;
1424
1425         /* Call dynamic linker stage-3, __dls3, looking it up
1426          * symbolically as a barrier against moving the address
1427          * load across the above relocation processing. */
1428         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1429         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1430         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1431 }
1432
1433 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1434  * fully functional. Its job is to load (if not already loaded) and
1435  * process dependencies and relocations for the main application and
1436  * transfer control to its entry point. */
1437
1438 _Noreturn void __dls3(size_t *sp)
1439 {
1440         static struct dso app, vdso;
1441         size_t aux[AUX_CNT], *auxv;
1442         size_t i;
1443         char *env_preload=0;
1444         size_t vdso_base;
1445         int argc = *sp;
1446         char **argv = (void *)(sp+1);
1447         char **argv_orig = argv;
1448         char **envp = argv+argc+1;
1449
1450         /* Find aux vector just past environ[] and use it to initialize
1451          * global data that may be needed before we can make syscalls. */
1452         __environ = envp;
1453         for (i=argc+1; argv[i]; i++);
1454         libc.auxv = auxv = (void *)(argv+i+1);
1455         decode_vec(auxv, aux, AUX_CNT);
1456         __hwcap = aux[AT_HWCAP];
1457         libc.page_size = aux[AT_PAGESZ];
1458         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1459                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1460
1461         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1462          * use during dynamic linking. If possible it will also serve as the
1463          * thread pointer at runtime. */
1464         libc.tls_size = sizeof builtin_tls;
1465         libc.tls_align = tls_align;
1466         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1467                 a_crash();
1468         }
1469
1470         /* Only trust user/env if kernel says we're not suid/sgid */
1471         if (!libc.secure) {
1472                 env_path = getenv("LD_LIBRARY_PATH");
1473                 env_preload = getenv("LD_PRELOAD");
1474         }
1475
1476         /* If the main program was already loaded by the kernel,
1477          * AT_PHDR will point to some location other than the dynamic
1478          * linker's program headers. */
1479         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1480                 size_t interp_off = 0;
1481                 size_t tls_image = 0;
1482                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1483                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1484                 app.phnum = aux[AT_PHNUM];
1485                 app.phentsize = aux[AT_PHENT];
1486                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1487                         if (phdr->p_type == PT_PHDR)
1488                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1489                         else if (phdr->p_type == PT_INTERP)
1490                                 interp_off = (size_t)phdr->p_vaddr;
1491                         else if (phdr->p_type == PT_TLS) {
1492                                 tls_image = phdr->p_vaddr;
1493                                 app.tls.len = phdr->p_filesz;
1494                                 app.tls.size = phdr->p_memsz;
1495                                 app.tls.align = phdr->p_align;
1496                         }
1497                 }
1498                 if (DL_FDPIC) app.loadmap = app_loadmap;
1499                 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1500                 if (interp_off) ldso.name = laddr(&app, interp_off);
1501                 if ((aux[0] & (1UL<<AT_EXECFN))
1502                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1503                         app.name = (char *)aux[AT_EXECFN];
1504                 else
1505                         app.name = argv[0];
1506                 kernel_mapped_dso(&app);
1507         } else {
1508                 int fd;
1509                 char *ldname = argv[0];
1510                 size_t l = strlen(ldname);
1511                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1512                 argv++;
1513                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1514                         char *opt = argv[0]+2;
1515                         *argv++ = (void *)-1;
1516                         if (!*opt) {
1517                                 break;
1518                         } else if (!memcmp(opt, "list", 5)) {
1519                                 ldd_mode = 1;
1520                         } else if (!memcmp(opt, "library-path", 12)) {
1521                                 if (opt[12]=='=') env_path = opt+13;
1522                                 else if (opt[12]) *argv = 0;
1523                                 else if (*argv) env_path = *argv++;
1524                         } else if (!memcmp(opt, "preload", 7)) {
1525                                 if (opt[7]=='=') env_preload = opt+8;
1526                                 else if (opt[7]) *argv = 0;
1527                                 else if (*argv) env_preload = *argv++;
1528                         } else {
1529                                 argv[0] = 0;
1530                         }
1531                 }
1532                 argv[-1] = (void *)(argc - (argv-argv_orig));
1533                 if (!argv[0]) {
1534                         dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1535                                 "Version %s\n"
1536                                 "Dynamic Program Loader\n"
1537                                 "Usage: %s [options] [--] pathname%s\n",
1538                                 __libc_get_version(), ldname,
1539                                 ldd_mode ? "" : " [args]");
1540                         _exit(1);
1541                 }
1542                 fd = open(argv[0], O_RDONLY);
1543                 if (fd < 0) {
1544                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1545                         _exit(1);
1546                 }
1547                 runtime = 1;
1548                 Ehdr *ehdr = (void *)map_library(fd, &app);
1549                 if (!ehdr) {
1550                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1551                         _exit(1);
1552                 }
1553                 runtime = 0;
1554                 close(fd);
1555                 ldso.name = ldname;
1556                 app.name = argv[0];
1557                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1558                 /* Find the name that would have been used for the dynamic
1559                  * linker had ldd not taken its place. */
1560                 if (ldd_mode) {
1561                         for (i=0; i<app.phnum; i++) {
1562                                 if (app.phdr[i].p_type == PT_INTERP)
1563                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1564                         }
1565                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1566                 }
1567         }
1568         if (app.tls.size) {
1569                 libc.tls_head = tls_tail = &app.tls;
1570                 app.tls_id = tls_cnt = 1;
1571 #ifdef TLS_ABOVE_TP
1572                 app.tls.offset = 0;
1573                 tls_offset = app.tls.size
1574                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1575                         & (app.tls.align-1) );
1576 #else
1577                 tls_offset = app.tls.offset = app.tls.size
1578                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1579                         & (app.tls.align-1) );
1580 #endif
1581                 tls_align = MAXP2(tls_align, app.tls.align);
1582         }
1583         decode_dyn(&app);
1584         if (DL_FDPIC) {
1585                 makefuncdescs(&app);
1586                 if (!app.loadmap) {
1587                         app.loadmap = (void *)&app_dummy_loadmap;
1588                         app.loadmap->nsegs = 1;
1589                         app.loadmap->segs[0].addr = (size_t)app.map;
1590                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1591                                 - (size_t)app.base;
1592                         app.loadmap->segs[0].p_memsz = app.map_len;
1593                 }
1594                 argv[-3] = (void *)app.loadmap;
1595         }
1596
1597         /* Initial dso chain consists only of the app. */
1598         head = tail = syms_tail = &app;
1599
1600         /* Donate unused parts of app and library mapping to malloc */
1601         reclaim_gaps(&app);
1602         reclaim_gaps(&ldso);
1603
1604         /* Load preload/needed libraries, add symbols to global namespace. */
1605         if (env_preload) load_preload(env_preload);
1606         load_deps(&app);
1607         for (struct dso *p=head; p; p=p->next)
1608                 add_syms(p);
1609
1610         /* Attach to vdso, if provided by the kernel, last so that it does
1611          * not become part of the global namespace.  */
1612         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1613                 Ehdr *ehdr = (void *)vdso_base;
1614                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1615                 vdso.phnum = ehdr->e_phnum;
1616                 vdso.phentsize = ehdr->e_phentsize;
1617                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1618                         if (phdr->p_type == PT_DYNAMIC)
1619                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1620                         if (phdr->p_type == PT_LOAD)
1621                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1622                 }
1623                 vdso.name = "";
1624                 vdso.shortname = "linux-gate.so.1";
1625                 vdso.relocated = 1;
1626                 decode_dyn(&vdso);
1627                 vdso.prev = tail;
1628                 tail->next = &vdso;
1629                 tail = &vdso;
1630         }
1631
1632         for (i=0; app.dynv[i]; i+=2) {
1633                 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1634                         app.dynv[i+1] = (size_t)&debug;
1635                 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1636                         size_t *ptr = (size_t *) app.dynv[i+1];
1637                         *ptr = (size_t)&debug;
1638                 }
1639         }
1640
1641         /* The main program must be relocated LAST since it may contin
1642          * copy relocations which depend on libraries' relocations. */
1643         reloc_all(app.next);
1644         reloc_all(&app);
1645
1646         update_tls_size();
1647         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1648                 void *initial_tls = calloc(libc.tls_size, 1);
1649                 if (!initial_tls) {
1650                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1651                                 argv[0], libc.tls_size);
1652                         _exit(127);
1653                 }
1654                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1655                         a_crash();
1656                 }
1657         } else {
1658                 size_t tmp_tls_size = libc.tls_size;
1659                 pthread_t self = __pthread_self();
1660                 /* Temporarily set the tls size to the full size of
1661                  * builtin_tls so that __copy_tls will use the same layout
1662                  * as it did for before. Then check, just to be safe. */
1663                 libc.tls_size = sizeof builtin_tls;
1664                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1665                 libc.tls_size = tmp_tls_size;
1666         }
1667         static_tls_cnt = tls_cnt;
1668
1669         if (ldso_fail) _exit(127);
1670         if (ldd_mode) _exit(0);
1671
1672         /* Switch to runtime mode: any further failures in the dynamic
1673          * linker are a reportable failure rather than a fatal startup
1674          * error. */
1675         runtime = 1;
1676
1677         debug.ver = 1;
1678         debug.bp = dl_debug_state;
1679         debug.head = head;
1680         debug.base = ldso.base;
1681         debug.state = 0;
1682         _dl_debug_state();
1683
1684         errno = 0;
1685
1686         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1687         for(;;);
1688 }
1689
1690 static void prepare_lazy(struct dso *p)
1691 {
1692         size_t dyn[DYN_CNT], n, flags1=0;
1693         decode_vec(p->dynv, dyn, DYN_CNT);
1694         search_vec(p->dynv, &flags1, DT_FLAGS_1);
1695         if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1696                 return;
1697         n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1698         if (NEED_MIPS_GOT_RELOCS) {
1699                 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1700                 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1701                 n += i-j;
1702         }
1703         p->lazy = calloc(n, 3*sizeof(size_t));
1704         if (!p->lazy) {
1705                 error("Error preparing lazy relocation for %s: %m", p->name);
1706                 longjmp(*rtld_fail, 1);
1707         }
1708         p->lazy_next = lazy_head;
1709         lazy_head = p;
1710 }
1711
1712 void *dlopen(const char *file, int mode)
1713 {
1714         struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1715         struct tls_module *orig_tls_tail;
1716         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1717         size_t i;
1718         int cs;
1719         jmp_buf jb;
1720
1721         if (!file) return head;
1722
1723         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1724         pthread_rwlock_wrlock(&lock);
1725         __inhibit_ptc();
1726
1727         p = 0;
1728         orig_tls_tail = tls_tail;
1729         orig_tls_cnt = tls_cnt;
1730         orig_tls_offset = tls_offset;
1731         orig_tls_align = tls_align;
1732         orig_lazy_head = lazy_head;
1733         orig_syms_tail = syms_tail;
1734         orig_tail = tail;
1735         noload = mode & RTLD_NOLOAD;
1736
1737         rtld_fail = &jb;
1738         if (setjmp(*rtld_fail)) {
1739                 /* Clean up anything new that was (partially) loaded */
1740                 revert_syms(orig_syms_tail);
1741                 for (p=orig_tail->next; p; p=next) {
1742                         next = p->next;
1743                         while (p->td_index) {
1744                                 void *tmp = p->td_index->next;
1745                                 free(p->td_index);
1746                                 p->td_index = tmp;
1747                         }
1748                         free(p->funcdescs);
1749                         if (p->rpath != p->rpath_orig)
1750                                 free(p->rpath);
1751                         free(p->deps);
1752                         unmap_library(p);
1753                         free(p);
1754                 }
1755                 if (!orig_tls_tail) libc.tls_head = 0;
1756                 tls_tail = orig_tls_tail;
1757                 if (tls_tail) tls_tail->next = 0;
1758                 tls_cnt = orig_tls_cnt;
1759                 tls_offset = orig_tls_offset;
1760                 tls_align = orig_tls_align;
1761                 lazy_head = orig_lazy_head;
1762                 tail = orig_tail;
1763                 tail->next = 0;
1764                 p = 0;
1765                 goto end;
1766         } else p = load_library(file, head);
1767
1768         if (!p) {
1769                 error(noload ?
1770                         "Library %s is not already loaded" :
1771                         "Error loading shared library %s: %m",
1772                         file);
1773                 goto end;
1774         }
1775
1776         /* First load handling */
1777         if (!p->relocated) {
1778                 load_deps(p);
1779                 if ((mode & RTLD_LAZY)) {
1780                         prepare_lazy(p);
1781                         if (p->deps) for (i=0; p->deps[i]; i++)
1782                                 if (!p->deps[i]->relocated)
1783                                         prepare_lazy(p->deps[i]);
1784                 }
1785                 /* Make new symbols global, at least temporarily, so we can do
1786                  * relocations. If not RTLD_GLOBAL, this is reverted below. */
1787                 add_syms(p);
1788                 if (p->deps) for (i=0; p->deps[i]; i++)
1789                         add_syms(p->deps[i]);
1790                 reloc_all(p);
1791         }
1792
1793         /* If RTLD_GLOBAL was not specified, undo any new additions
1794          * to the global symbol table. This is a nop if the library was
1795          * previously loaded and already global. */
1796         if (!(mode & RTLD_GLOBAL))
1797                 revert_syms(orig_syms_tail);
1798
1799         /* Processing of deferred lazy relocations must not happen until
1800          * the new libraries are committed; otherwise we could end up with
1801          * relocations resolved to symbol definitions that get removed. */
1802         redo_lazy_relocs();
1803
1804         update_tls_size();
1805         _dl_debug_state();
1806         orig_tail = tail;
1807 end:
1808         __release_ptc();
1809         if (p) gencnt++;
1810         pthread_rwlock_unlock(&lock);
1811         if (p) do_init_fini(orig_tail);
1812         pthread_setcancelstate(cs, 0);
1813         return p;
1814 }
1815
1816 __attribute__((__visibility__("hidden")))
1817 int __dl_invalid_handle(void *h)
1818 {
1819         struct dso *p;
1820         for (p=head; p; p=p->next) if (h==p) return 0;
1821         error("Invalid library handle %p", (void *)h);
1822         return 1;
1823 }
1824
1825 static void *addr2dso(size_t a)
1826 {
1827         struct dso *p;
1828         size_t i;
1829         if (DL_FDPIC) for (p=head; p; p=p->next) {
1830                 i = count_syms(p);
1831                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1832                         return p;
1833         }
1834         for (p=head; p; p=p->next) {
1835                 if (DL_FDPIC && p->loadmap) {
1836                         for (i=0; i<p->loadmap->nsegs; i++) {
1837                                 if (a-p->loadmap->segs[i].p_vaddr
1838                                     < p->loadmap->segs[i].p_memsz)
1839                                         return p;
1840                         }
1841                 } else {
1842                         if (a-(size_t)p->map < p->map_len)
1843                                 return p;
1844                 }
1845         }
1846         return 0;
1847 }
1848
1849 void *__tls_get_addr(tls_mod_off_t *);
1850
1851 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1852 {
1853         size_t i;
1854         uint32_t h = 0, gh = 0, *ght;
1855         Sym *sym;
1856         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1857                 if (p == RTLD_DEFAULT) {
1858                         p = head;
1859                 } else if (p == RTLD_NEXT) {
1860                         p = addr2dso((size_t)ra);
1861                         if (!p) p=head;
1862                         p = p->next;
1863                 }
1864                 struct symdef def = find_sym(p, s, 0);
1865                 if (!def.sym) goto failed;
1866                 if ((def.sym->st_info&0xf) == STT_TLS)
1867                         return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
1868                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1869                         return def.dso->funcdescs + (def.sym - def.dso->syms);
1870                 return laddr(def.dso, def.sym->st_value);
1871         }
1872         if (__dl_invalid_handle(p))
1873                 return 0;
1874         if ((ght = p->ghashtab)) {
1875                 gh = gnu_hash(s);
1876                 sym = gnu_lookup(gh, ght, p, s);
1877         } else {
1878                 h = sysv_hash(s);
1879                 sym = sysv_lookup(s, h, p);
1880         }
1881         if (sym && (sym->st_info&0xf) == STT_TLS)
1882                 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
1883         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1884                 return p->funcdescs + (sym - p->syms);
1885         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1886                 return laddr(p, sym->st_value);
1887         if (p->deps) for (i=0; p->deps[i]; i++) {
1888                 if ((ght = p->deps[i]->ghashtab)) {
1889                         if (!gh) gh = gnu_hash(s);
1890                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1891                 } else {
1892                         if (!h) h = sysv_hash(s);
1893                         sym = sysv_lookup(s, h, p->deps[i]);
1894                 }
1895                 if (sym && (sym->st_info&0xf) == STT_TLS)
1896                         return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
1897                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1898                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1899                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1900                         return laddr(p->deps[i], sym->st_value);
1901         }
1902 failed:
1903         error("Symbol not found: %s", s);
1904         return 0;
1905 }
1906
1907 int dladdr(const void *addr, Dl_info *info)
1908 {
1909         struct dso *p;
1910         Sym *sym, *bestsym;
1911         uint32_t nsym;
1912         char *strings;
1913         void *best = 0;
1914
1915         pthread_rwlock_rdlock(&lock);
1916         p = addr2dso((size_t)addr);
1917         pthread_rwlock_unlock(&lock);
1918
1919         if (!p) return 0;
1920
1921         sym = p->syms;
1922         strings = p->strings;
1923         nsym = count_syms(p);
1924
1925         if (DL_FDPIC) {
1926                 size_t idx = ((size_t)addr-(size_t)p->funcdescs)
1927                         / sizeof(*p->funcdescs);
1928                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1929                         best = p->funcdescs + idx;
1930                         bestsym = sym + idx;
1931                 }
1932         }
1933
1934         if (!best) for (; nsym; nsym--, sym++) {
1935                 if (sym->st_value
1936                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1937                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1938                         void *symaddr = laddr(p, sym->st_value);
1939                         if (symaddr > addr || symaddr < best)
1940                                 continue;
1941                         best = symaddr;
1942                         bestsym = sym;
1943                         if (addr == symaddr)
1944                                 break;
1945                 }
1946         }
1947
1948         if (!best) return 0;
1949
1950         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
1951                 best = p->funcdescs + (bestsym - p->syms);
1952
1953         info->dli_fname = p->name;
1954         info->dli_fbase = p->base;
1955         info->dli_sname = strings + bestsym->st_name;
1956         info->dli_saddr = best;
1957
1958         return 1;
1959 }
1960
1961 __attribute__((__visibility__("hidden")))
1962 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1963 {
1964         void *res;
1965         pthread_rwlock_rdlock(&lock);
1966         res = do_dlsym(p, s, ra);
1967         pthread_rwlock_unlock(&lock);
1968         return res;
1969 }
1970
1971 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1972 {
1973         struct dso *current;
1974         struct dl_phdr_info info;
1975         int ret = 0;
1976         for(current = head; current;) {
1977                 info.dlpi_addr      = (uintptr_t)current->base;
1978                 info.dlpi_name      = current->name;
1979                 info.dlpi_phdr      = current->phdr;
1980                 info.dlpi_phnum     = current->phnum;
1981                 info.dlpi_adds      = gencnt;
1982                 info.dlpi_subs      = 0;
1983                 info.dlpi_tls_modid = current->tls_id;
1984                 info.dlpi_tls_data  = current->tls.image;
1985
1986                 ret = (callback)(&info, sizeof (info), data);
1987
1988                 if (ret != 0) break;
1989
1990                 pthread_rwlock_rdlock(&lock);
1991                 current = current->next;
1992                 pthread_rwlock_unlock(&lock);
1993         }
1994         return ret;
1995 }
1996
1997 __attribute__((__visibility__("hidden")))
1998 void __dl_vseterr(const char *, va_list);
1999
2000 static void error(const char *fmt, ...)
2001 {
2002         va_list ap;
2003         va_start(ap, fmt);
2004         if (!runtime) {
2005                 vdprintf(2, fmt, ap);
2006                 dprintf(2, "\n");
2007                 ldso_fail = 1;
2008                 va_end(ap);
2009                 return;
2010         }
2011         __dl_vseterr(fmt, ap);
2012         va_end(ap);
2013 }