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