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