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

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <stdarg.h>
   5 #include <stddef.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <stdint.h>
   9 #include <elf.h>
  10 #include <sys/mman.h>
  11 #include <limits.h>
  12 #include <fcntl.h>
  13 #include <sys/stat.h>
  14 #include <errno.h>
  15 #include <link.h>
  16 #include <setjmp.h>
  17 #include <pthread.h>
  18 #include <ctype.h>
  19 #include <dlfcn.h>
  20 #include "pthread_impl.h"
  21 #include "libc.h"
  22 #include "dynlink.h"
  23
  24 static void error(const char *, ...);
  25
  26 #define MAXP2(a,b) (-(-(a)&-(b)))
  27 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  28
  29 struct debug {
  30         int ver;
  31         void *head;
  32         void (*bp)(void);
  33         int state;
  34         void *base;
  35 };
  36
  37 struct td_index {
  38         size_t args[2];
  39         struct td_index *next;
  40 };
  41
  42 struct dso {
  43 #if DL_FDPIC
  44         struct fdpic_loadmap *loadmap;
  45 #else
  46         unsigned char *base;
  47 #endif
  48         char *name;
  49         size_t *dynv;
  50         struct dso *next, *prev;
  51
  52         Phdr *phdr;
  53         int phnum;
  54         size_t phentsize;
  55         Sym *syms;
  56         Elf_Symndx *hashtab;
  57         uint32_t *ghashtab;
  58         int16_t *versym;
  59         char *strings;
  60         struct dso *syms_next, *lazy_next;
  61         size_t *lazy, lazy_cnt;
  62         unsigned char *map;
  63         size_t map_len;
  64         dev_t dev;
  65         ino_t ino;
  66         char relocated;
  67         char constructed;
  68         char kernel_mapped;
  69         struct dso **deps, *needed_by;
  70         char *rpath_orig, *rpath;
  71         struct tls_module tls;
  72         size_t tls_id;
  73         size_t relro_start, relro_end;
  74         void **new_dtv;
  75         unsigned char *new_tls;
  76         volatile int new_dtv_idx, new_tls_idx;
  77         struct td_index *td_index;
  78         struct dso *fini_next;
  79         char *shortname;
  80 #if DL_FDPIC
  81         unsigned char *base;
  82 #else
  83         struct fdpic_loadmap *loadmap;
  84 #endif
  85         struct funcdesc {
  86                 void *addr;
  87                 size_t *got;
  88         } *funcdescs;
  89         size_t *got;
  90         char buf[];
  91 };
  92
  93 struct symdef {
  94         Sym *sym;
  95         struct dso *dso;
  96 };
  97
  98 int __init_tp(void *);
  99 void __init_libc(char **, char *);
 100 void *__copy_tls(unsigned char *);
 101
 102 __attribute__((__visibility__("hidden")))
 103 const char *__libc_get_version(void);
 104
 105 static struct builtin_tls {
 106         char c;
 107         struct pthread pt;
 108         void *space[16];
 109 } builtin_tls[1];
 110 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 111
 112 #define ADDEND_LIMIT 4096
 113 static size_t *saved_addends, *apply_addends_to;
 114
 115 static struct dso ldso;
 116 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
 117 static char *env_path, *sys_path;
 118 static unsigned long long gencnt;
 119 static int runtime;
 120 static int ldd_mode;
 121 static int ldso_fail;
 122 static int noload;
 123 static jmp_buf *rtld_fail;
 124 static pthread_rwlock_t lock;
 125 static struct debug debug;
 126 static struct tls_module *tls_tail;
 127 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
 128 static size_t static_tls_cnt;
 129 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 130 static struct fdpic_loadmap *app_loadmap;
 131 static struct fdpic_dummy_loadmap app_dummy_loadmap;
 132 static struct dso *const nodeps_dummy;
 133
 134 struct debug *_dl_debug_addr = &debug;
 135
 136 __attribute__((__visibility__("hidden")))
 137 extern int __malloc_replaced;
 138
 139 __attribute__((__visibility__("hidden")))
 140 void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
 141
 142 __attribute__((__visibility__("hidden")))
 143 extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
 144
 145 weak_alias(__init_array_start, __init_array_end);
 146 weak_alias(__fini_array_start, __fini_array_end);
 147
 148 static int dl_strcmp(const char *l, const char *r)
 149 {
 150         for (; *l==*r && *l; l++, r++);
 151         return *(unsigned char *)l - *(unsigned char *)r;
 152 }
 153 #define strcmp(l,r) dl_strcmp(l,r)
 154
 155 /* Compute load address for a virtual address in a given dso. */
 156 #if DL_FDPIC
 157 static void *laddr(const struct dso *p, size_t v)
 158 {
 159         size_t j=0;
 160         if (!p->loadmap) return p->base + v;
 161         for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
 162         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 163 }
 164 static void *laddr_pg(const struct dso *p, size_t v)
 165 {
 166         size_t j=0;
 167         size_t pgsz = PAGE_SIZE;
 168         if (!p->loadmap) return p->base + v;
 169         for (j=0; ; j++) {
 170                 size_t a = p->loadmap->segs[j].p_vaddr;
 171                 size_t b = a + p->loadmap->segs[j].p_memsz;
 172                 a &= -pgsz;
 173                 b += pgsz-1;
 174                 b &= -pgsz;
 175                 if (v-a<b-a) break;
 176         }
 177         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 178 }
 179 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
 180         laddr(p, v), (p)->got })
 181 #else
 182 #define laddr(p, v) (void *)((p)->base + (v))
 183 #define laddr_pg(p, v) laddr(p, v)
 184 #define fpaddr(p, v) ((void (*)())laddr(p, v))
 185 #endif
 186
 187 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 188 {
 189         size_t i;
 190         for (i=0; i<cnt; i++) a[i] = 0;
 191         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 192                 a[0] |= 1UL<<v[0];
 193                 a[v[0]] = v[1];
 194         }
 195 }
 196
 197 static int search_vec(size_t *v, size_t *r, size_t key)
 198 {
 199         for (; v[0]!=key; v+=2)
 200                 if (!v[0]) return 0;
 201         *r = v[1];
 202         return 1;
 203 }
 204
 205 static uint32_t sysv_hash(const char *s0)
 206 {
 207         const unsigned char *s = (void *)s0;
 208         uint_fast32_t h = 0;
 209         while (*s) {
 210                 h = 16*h + *s++;
 211                 h ^= h>>24 & 0xf0;
 212         }
 213         return h & 0xfffffff;
 214 }
 215
 216 static uint32_t gnu_hash(const char *s0)
 217 {
 218         const unsigned char *s = (void *)s0;
 219         uint_fast32_t h = 5381;
 220         for (; *s; s++)
 221                 h += h*32 + *s;
 222         return h;
 223 }
 224
 225 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 226 {
 227         size_t i;
 228         Sym *syms = dso->syms;
 229         Elf_Symndx *hashtab = dso->hashtab;
 230         char *strings = dso->strings;
 231         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 232                 if ((!dso->versym || dso->versym[i] >= 0)
 233                     && (!strcmp(s, strings+syms[i].st_name)))
 234                         return syms+i;
 235         }
 236         return 0;
 237 }
 238
 239 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 240 {
 241         uint32_t nbuckets = hashtab[0];
 242         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 243         uint32_t i = buckets[h1 % nbuckets];
 244
 245         if (!i) return 0;
 246
 247         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 248
 249         for (h1 |= 1; ; i++) {
 250                 uint32_t h2 = *hashval++;
 251                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 252                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 253                         return dso->syms+i;
 254                 if (h2 & 1) break;
 255         }
 256
 257         return 0;
 258 }
 259
 260 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 261 {
 262         const size_t *bloomwords = (const void *)(hashtab+4);
 263         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 264         if (!(f & fmask)) return 0;
 265
 266         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 267         if (!(f & 1)) return 0;
 268
 269         return gnu_lookup(h1, hashtab, dso, s);
 270 }
 271
 272 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 273 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 274
 275 #ifndef ARCH_SYM_REJECT_UND
 276 #define ARCH_SYM_REJECT_UND(s) 0
 277 #endif
 278
 279 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 280 {
 281         uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
 282         size_t ghm = 1ul << gh % (8*sizeof(size_t));
 283         struct symdef def = {0};
 284         for (; dso; dso=dso->syms_next) {
 285                 Sym *sym;
 286                 if ((ght = dso->ghashtab)) {
 287                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 288                 } else {
 289                         if (!h) h = sysv_hash(s);
 290                         sym = sysv_lookup(s, h, dso);
 291                 }
 292                 if (!sym) continue;
 293                 if (!sym->st_shndx)
 294                         if (need_def || (sym->st_info&0xf) == STT_TLS
 295                             || ARCH_SYM_REJECT_UND(sym))
 296                                 continue;
 297                 if (!sym->st_value)
 298                         if ((sym->st_info&0xf) != STT_TLS)
 299                                 continue;
 300                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 301                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 302                 def.sym = sym;
 303                 def.dso = dso;
 304                 break;
 305         }
 306         return def;
 307 }
 308
 309 __attribute__((__visibility__("hidden")))
 310 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 311
 312 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 313 {
 314         unsigned char *base = dso->base;
 315         Sym *syms = dso->syms;
 316         char *strings = dso->strings;
 317         Sym *sym;
 318         const char *name;
 319         void *ctx;
 320         int type;
 321         int sym_index;
 322         struct symdef def;
 323         size_t *reloc_addr;
 324         size_t sym_val;
 325         size_t tls_val;
 326         size_t addend;
 327         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 328
 329         if (dso == &ldso) {
 330                 /* Only ldso's REL table needs addend saving/reuse. */
 331                 if (rel == apply_addends_to)
 332                         reuse_addends = 1;
 333                 skip_relative = 1;
 334         }
 335
 336         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 337                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 338                 type = R_TYPE(rel[1]);
 339                 if (type == REL_NONE) continue;
 340                 reloc_addr = laddr(dso, rel[0]);
 341
 342                 if (stride > 2) {
 343                         addend = rel[2];
 344                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 345                         addend = 0;
 346                 } else if (reuse_addends) {
 347                         /* Save original addend in stage 2 where the dso
 348                          * chain consists of just ldso; otherwise read back
 349                          * saved addend since the inline one was clobbered. */
 350                         if (head==&ldso)
 351                                 saved_addends[save_slot] = *reloc_addr;
 352                         addend = saved_addends[save_slot++];
 353                 } else {
 354                         addend = *reloc_addr;
 355                 }
 356
 357                 sym_index = R_SYM(rel[1]);
 358                 if (sym_index) {
 359                         sym = syms + sym_index;
 360                         name = strings + sym->st_name;
 361                         ctx = type==REL_COPY ? head->syms_next : head;
 362                         def = (sym->st_info&0xf) == STT_SECTION
 363                                 ? (struct symdef){ .dso = dso, .sym = sym }
 364                                 : find_sym(ctx, name, type==REL_PLT);
 365                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 366                             || sym->st_info>>4 != STB_WEAK)) {
 367                                 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
 368                                         dso->lazy[3*dso->lazy_cnt+0] = rel[0];
 369                                         dso->lazy[3*dso->lazy_cnt+1] = rel[1];
 370                                         dso->lazy[3*dso->lazy_cnt+2] = addend;
 371                                         dso->lazy_cnt++;
 372                                         continue;
 373                                 }
 374                                 error("Error relocating %s: %s: symbol not found",
 375                                         dso->name, name);
 376                                 if (runtime) longjmp(*rtld_fail, 1);
 377                                 continue;
 378                         }
 379                 } else {
 380                         sym = 0;
 381                         def.sym = 0;
 382                         def.dso = dso;
 383                 }
 384
 385                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 386                 tls_val = def.sym ? def.sym->st_value : 0;
 387
 388                 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
 389                     && runtime && def.dso->tls_id > static_tls_cnt) {
 390                         error("Error relocating %s: %s: initial-exec TLS "
 391                                 "resolves to dynamic definition in %s",
 392                                 dso->name, name, def.dso->name);
 393                         longjmp(*rtld_fail, 1);
 394                 }
 395
 396                 switch(type) {
 397                 case REL_NONE:
 398                         break;
 399                 case REL_OFFSET:
 400                         addend -= (size_t)reloc_addr;
 401                 case REL_SYMBOLIC:
 402                 case REL_GOT:
 403                 case REL_PLT:
 404                         *reloc_addr = sym_val + addend;
 405                         break;
 406                 case REL_RELATIVE:
 407                         *reloc_addr = (size_t)base + addend;
 408                         break;
 409                 case REL_SYM_OR_REL:
 410                         if (sym) *reloc_addr = sym_val + addend;
 411                         else *reloc_addr = (size_t)base + addend;
 412                         break;
 413                 case REL_COPY:
 414                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 415                         break;
 416                 case REL_OFFSET32:
 417                         *(uint32_t *)reloc_addr = sym_val + addend
 418                                 - (size_t)reloc_addr;
 419                         break;
 420                 case REL_FUNCDESC:
 421                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 422                                 + (def.sym - def.dso->syms)) : 0;
 423                         break;
 424                 case REL_FUNCDESC_VAL:
 425                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 426                         else *reloc_addr = sym_val;
 427                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 428                         break;
 429                 case REL_DTPMOD:
 430                         *reloc_addr = def.dso->tls_id;
 431                         break;
 432                 case REL_DTPOFF:
 433                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 434                         break;
 435 #ifdef TLS_ABOVE_TP
 436                 case REL_TPOFF:
 437                         *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
 438                         break;
 439 #else
 440                 case REL_TPOFF:
 441                         *reloc_addr = tls_val - def.dso->tls.offset + addend;
 442                         break;
 443                 case REL_TPOFF_NEG:
 444                         *reloc_addr = def.dso->tls.offset - tls_val + addend;
 445                         break;
 446 #endif
 447                 case REL_TLSDESC:
 448                         if (stride<3) addend = reloc_addr[1];
 449                         if (runtime && def.dso->tls_id > static_tls_cnt) {
 450                                 struct td_index *new = malloc(sizeof *new);
 451                                 if (!new) {
 452                                         error(
 453                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 454                                         dso->name, sym ? name : "(local)" );
 455                                         longjmp(*rtld_fail, 1);
 456                                 }
 457                                 new->next = dso->td_index;
 458                                 dso->td_index = new;
 459                                 new->args[0] = def.dso->tls_id;
 460                                 new->args[1] = tls_val + addend;
 461                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 462                                 reloc_addr[1] = (size_t)new;
 463                         } else {
 464                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 465 #ifdef TLS_ABOVE_TP
 466                                 reloc_addr[1] = tls_val + def.dso->tls.offset
 467                                         + TPOFF_K + addend;
 468 #else
 469                                 reloc_addr[1] = tls_val - def.dso->tls.offset
 470                                         + addend;
 471 #endif
 472                         }
 473                         break;
 474                 default:
 475                         error("Error relocating %s: unsupported relocation type %d",
 476                                 dso->name, type);
 477                         if (runtime) longjmp(*rtld_fail, 1);
 478                         continue;
 479                 }
 480         }
 481 }
 482
 483 static void redo_lazy_relocs()
 484 {
 485         struct dso *p = lazy_head, *next;
 486         lazy_head = 0;
 487         for (; p; p=next) {
 488                 next = p->lazy_next;
 489                 size_t size = p->lazy_cnt*3*sizeof(size_t);
 490                 p->lazy_cnt = 0;
 491                 do_relocs(p, p->lazy, size, 3);
 492                 if (p->lazy_cnt) {
 493                         p->lazy_next = lazy_head;
 494                         lazy_head = p;
 495                 } else {
 496                         free(p->lazy);
 497                         p->lazy = 0;
 498                         p->lazy_next = 0;
 499                 }
 500         }
 501 }
 502
 503 /* A huge hack: to make up for the wastefulness of shared libraries
 504  * needing at least a page of dirty memory even if they have no global
 505  * data, we reclaim the gaps at the beginning and end of writable maps
 506  * and "donate" them to the heap. */
 507
 508 static void reclaim(struct dso *dso, size_t start, size_t end)
 509 {
 510         void __malloc_donate(char *, char *);
 511         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 512         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 513         if (start >= end) return;
 514         char *base = laddr_pg(dso, start);
 515         __malloc_donate(base, base+(end-start));
 516 }
 517
 518 static void reclaim_gaps(struct dso *dso)
 519 {
 520         Phdr *ph = dso->phdr;
 521         size_t phcnt = dso->phnum;
 522
 523         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 524                 if (ph->p_type!=PT_LOAD) continue;
 525                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 526                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 527                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 528                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 529         }
 530 }
 531
 532 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 533 {
 534         static int no_map_fixed;
 535         char *q;
 536         if (!no_map_fixed) {
 537                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 538                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 539                         return q;
 540                 no_map_fixed = 1;
 541         }
 542         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 543         if (flags & MAP_ANONYMOUS) {
 544                 memset(p, 0, n);
 545                 return p;
 546         }
 547         ssize_t r;
 548         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 549         for (q=p; n; q+=r, off+=r, n-=r) {
 550                 r = read(fd, q, n);
 551                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 552                 if (!r) {
 553                         memset(q, 0, n);
 554                         break;
 555                 }
 556         }
 557         return p;
 558 }
 559
 560 static void unmap_library(struct dso *dso)
 561 {
 562         if (dso->loadmap) {
 563                 size_t i;
 564                 for (i=0; i<dso->loadmap->nsegs; i++) {
 565                         if (!dso->loadmap->segs[i].p_memsz)
 566                                 continue;
 567                         munmap((void *)dso->loadmap->segs[i].addr,
 568                                 dso->loadmap->segs[i].p_memsz);
 569                 }
 570                 free(dso->loadmap);
 571         } else if (dso->map && dso->map_len) {
 572                 munmap(dso->map, dso->map_len);
 573         }
 574 }
 575
 576 static void *map_library(int fd, struct dso *dso)
 577 {
 578         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 579         void *allocated_buf=0;
 580         size_t phsize;
 581         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 582         size_t this_min, this_max;
 583         size_t nsegs = 0;
 584         off_t off_start;
 585         Ehdr *eh;
 586         Phdr *ph, *ph0;
 587         unsigned prot;
 588         unsigned char *map=MAP_FAILED, *base;
 589         size_t dyn=0;
 590         size_t tls_image=0;
 591         size_t i;
 592
 593         ssize_t l = read(fd, buf, sizeof buf);
 594         eh = buf;
 595         if (l<0) return 0;
 596         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 597                 goto noexec;
 598         phsize = eh->e_phentsize * eh->e_phnum;
 599         if (phsize > sizeof buf - sizeof *eh) {
 600                 allocated_buf = malloc(phsize);
 601                 if (!allocated_buf) return 0;
 602                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 603                 if (l < 0) goto error;
 604                 if (l != phsize) goto noexec;
 605                 ph = ph0 = allocated_buf;
 606         } else if (eh->e_phoff + phsize > l) {
 607                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 608                 if (l < 0) goto error;
 609                 if (l != phsize) goto noexec;
 610                 ph = ph0 = (void *)(buf + 1);
 611         } else {
 612                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 613         }
 614         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 615                 if (ph->p_type == PT_DYNAMIC) {
 616                         dyn = ph->p_vaddr;
 617                 } else if (ph->p_type == PT_TLS) {
 618                         tls_image = ph->p_vaddr;
 619                         dso->tls.align = ph->p_align;
 620                         dso->tls.len = ph->p_filesz;
 621                         dso->tls.size = ph->p_memsz;
 622                 } else if (ph->p_type == PT_GNU_RELRO) {
 623                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 624                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 625                 }
 626                 if (ph->p_type != PT_LOAD) continue;
 627                 nsegs++;
 628                 if (ph->p_vaddr < addr_min) {
 629                         addr_min = ph->p_vaddr;
 630                         off_start = ph->p_offset;
 631                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 632                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 633                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 634                 }
 635                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 636                         addr_max = ph->p_vaddr+ph->p_memsz;
 637                 }
 638         }
 639         if (!dyn) goto noexec;
 640         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 641                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 642                         + nsegs * sizeof *dso->loadmap->segs);
 643                 if (!dso->loadmap) goto error;
 644                 dso->loadmap->nsegs = nsegs;
 645                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 646                         if (ph->p_type != PT_LOAD) continue;
 647                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 648                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 649                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 650                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 651                                 prot, MAP_PRIVATE,
 652                                 fd, ph->p_offset & -PAGE_SIZE);
 653                         if (map == MAP_FAILED) {
 654                                 unmap_library(dso);
 655                                 goto error;
 656                         }
 657                         dso->loadmap->segs[i].addr = (size_t)map +
 658                                 (ph->p_vaddr & PAGE_SIZE-1);
 659                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 660                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 661                         i++;
 662                         if (prot & PROT_WRITE) {
 663                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 664                                         + ph->p_filesz;
 665                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 666                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 667                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 668                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 669                                         pgend-pgbrk, prot,
 670                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 671                                         -1, off_start) == MAP_FAILED)
 672                                         goto error;
 673                                 memset(map + brk, 0, pgbrk-brk);
 674                         }
 675                 }
 676                 map = (void *)dso->loadmap->segs[0].addr;
 677                 map_len = 0;
 678                 goto done_mapping;
 679         }
 680         addr_max += PAGE_SIZE-1;
 681         addr_max &= -PAGE_SIZE;
 682         addr_min &= -PAGE_SIZE;
 683         off_start &= -PAGE_SIZE;
 684         map_len = addr_max - addr_min + off_start;
 685         /* The first time, we map too much, possibly even more than
 686          * the length of the file. This is okay because we will not
 687          * use the invalid part; we just need to reserve the right
 688          * amount of virtual address space to map over later. */
 689         map = DL_NOMMU_SUPPORT
 690                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 691                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 692                 : mmap((void *)addr_min, map_len, prot,
 693                         MAP_PRIVATE, fd, off_start);
 694         if (map==MAP_FAILED) goto error;
 695         dso->map = map;
 696         dso->map_len = map_len;
 697         /* If the loaded file is not relocatable and the requested address is
 698          * not available, then the load operation must fail. */
 699         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 700                 errno = EBUSY;
 701                 goto error;
 702         }
 703         base = map - addr_min;
 704         dso->phdr = 0;
 705         dso->phnum = 0;
 706         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 707                 if (ph->p_type != PT_LOAD) continue;
 708                 /* Check if the programs headers are in this load segment, and
 709                  * if so, record the address for use by dl_iterate_phdr. */
 710                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 711                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 712                         dso->phdr = (void *)(base + ph->p_vaddr
 713                                 + (eh->e_phoff-ph->p_offset));
 714                         dso->phnum = eh->e_phnum;
 715                         dso->phentsize = eh->e_phentsize;
 716                 }
 717                 this_min = ph->p_vaddr & -PAGE_SIZE;
 718                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 719                 off_start = ph->p_offset & -PAGE_SIZE;
 720                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 721                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 722                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 723                 /* Reuse the existing mapping for the lowest-address LOAD */
 724                 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
 725                         if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 726                                 goto error;
 727                 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
 728                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 729                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 730                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 731                         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)
 732                                 goto error;
 733                 }
 734         }
 735         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 736                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 737                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 738                             && errno != ENOSYS)
 739                                 goto error;
 740                         break;
 741                 }
 742 done_mapping:
 743         dso->base = base;
 744         dso->dynv = laddr(dso, dyn);
 745         if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
 746         free(allocated_buf);
 747         return map;
 748 noexec:
 749         errno = ENOEXEC;
 750 error:
 751         if (map!=MAP_FAILED) unmap_library(dso);
 752         free(allocated_buf);
 753         return 0;
 754 }
 755
 756 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 757 {
 758         size_t l;
 759         int fd;
 760         for (;;) {
 761                 s += strspn(s, ":\n");
 762                 l = strcspn(s, ":\n");
 763                 if (l-1 >= INT_MAX) return -1;
 764                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 765                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 766                         switch (errno) {
 767                         case ENOENT:
 768                         case ENOTDIR:
 769                         case EACCES:
 770                         case ENAMETOOLONG:
 771                                 break;
 772                         default:
 773                                 /* Any negative value but -1 will inhibit
 774                                  * futher path search. */
 775                                 return -2;
 776                         }
 777                 }
 778                 s += l;
 779         }
 780 }
 781
 782 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 783 {
 784         size_t n, l;
 785         const char *s, *t, *origin;
 786         char *d;
 787         if (p->rpath || !p->rpath_orig) return 0;
 788         if (!strchr(p->rpath_orig, '$')) {
 789                 p->rpath = p->rpath_orig;
 790                 return 0;
 791         }
 792         n = 0;
 793         s = p->rpath_orig;
 794         while ((t=strchr(s, '$'))) {
 795                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 796                         return 0;
 797                 s = t+1;
 798                 n++;
 799         }
 800         if (n > SSIZE_MAX/PATH_MAX) return 0;
 801
 802         if (p->kernel_mapped) {
 803                 /* $ORIGIN searches cannot be performed for the main program
 804                  * when it is suid/sgid/AT_SECURE. This is because the
 805                  * pathname is under the control of the caller of execve.
 806                  * For libraries, however, $ORIGIN can be processed safely
 807                  * since the library's pathname came from a trusted source
 808                  * (either system paths or a call to dlopen). */
 809                 if (libc.secure)
 810                         return 0;
 811                 l = readlink("/proc/self/exe", buf, buf_size);
 812                 if (l == -1) switch (errno) {
 813                 case ENOENT:
 814                 case ENOTDIR:
 815                 case EACCES:
 816                         break;
 817                 default:
 818                         return -1;
 819                 }
 820                 if (l >= buf_size)
 821                         return 0;
 822                 buf[l] = 0;
 823                 origin = buf;
 824         } else {
 825                 origin = p->name;
 826         }
 827         t = strrchr(origin, '/');
 828         if (t) {
 829                 l = t-origin;
 830         } else {
 831                 /* Normally p->name will always be an absolute or relative
 832                  * pathname containing at least one '/' character, but in the
 833                  * case where ldso was invoked as a command to execute a
 834                  * program in the working directory, app.name may not. Fix. */
 835                 origin = ".";
 836                 l = 1;
 837         }
 838         /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
 839         if (libc.secure && *origin != '/')
 840                 return 0;
 841         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 842         if (!p->rpath) return -1;
 843
 844         d = p->rpath;
 845         s = p->rpath_orig;
 846         while ((t=strchr(s, '$'))) {
 847                 memcpy(d, s, t-s);
 848                 d += t-s;
 849                 memcpy(d, origin, l);
 850                 d += l;
 851                 /* It was determined previously that the '$' is followed
 852                  * either by "ORIGIN" or "{ORIGIN}". */
 853                 s = t + 7 + 2*(t[1]=='{');
 854         }
 855         strcpy(d, s);
 856         return 0;
 857 }
 858
 859 static void decode_dyn(struct dso *p)
 860 {
 861         size_t dyn[DYN_CNT];
 862         decode_vec(p->dynv, dyn, DYN_CNT);
 863         p->syms = laddr(p, dyn[DT_SYMTAB]);
 864         p->strings = laddr(p, dyn[DT_STRTAB]);
 865         if (dyn[0]&(1<<DT_HASH))
 866                 p->hashtab = laddr(p, dyn[DT_HASH]);
 867         if (dyn[0]&(1<<DT_RPATH))
 868                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 869         if (dyn[0]&(1<<DT_RUNPATH))
 870                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 871         if (dyn[0]&(1<<DT_PLTGOT))
 872                 p->got = laddr(p, dyn[DT_PLTGOT]);
 873         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 874                 p->ghashtab = laddr(p, *dyn);
 875         if (search_vec(p->dynv, dyn, DT_VERSYM))
 876                 p->versym = laddr(p, *dyn);
 877 }
 878
 879 static size_t count_syms(struct dso *p)
 880 {
 881         if (p->hashtab) return p->hashtab[1];
 882
 883         size_t nsym, i;
 884         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 885         uint32_t *hashval;
 886         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 887                 if (buckets[i] > nsym)
 888                         nsym = buckets[i];
 889         }
 890         if (nsym) {
 891                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 892                 do nsym++;
 893                 while (!(*hashval++ & 1));
 894         }
 895         return nsym;
 896 }
 897
 898 static void *dl_mmap(size_t n)
 899 {
 900         void *p;
 901         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 902 #ifdef SYS_mmap2
 903         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 904 #else
 905         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 906 #endif
 907         return p == MAP_FAILED ? 0 : p;
 908 }
 909
 910 static void makefuncdescs(struct dso *p)
 911 {
 912         static int self_done;
 913         size_t nsym = count_syms(p);
 914         size_t i, size = nsym * sizeof(*p->funcdescs);
 915
 916         if (!self_done) {
 917                 p->funcdescs = dl_mmap(size);
 918                 self_done = 1;
 919         } else {
 920                 p->funcdescs = malloc(size);
 921         }
 922         if (!p->funcdescs) {
 923                 if (!runtime) a_crash();
 924                 error("Error allocating function descriptors for %s", p->name);
 925                 longjmp(*rtld_fail, 1);
 926         }
 927         for (i=0; i<nsym; i++) {
 928                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 929                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 930                         p->funcdescs[i].got = p->got;
 931                 } else {
 932                         p->funcdescs[i].addr = 0;
 933                         p->funcdescs[i].got = 0;
 934                 }
 935         }
 936 }
 937
 938 static struct dso *load_library(const char *name, struct dso *needed_by)
 939 {
 940         char buf[2*NAME_MAX+2];
 941         const char *pathname;
 942         unsigned char *map;
 943         struct dso *p, temp_dso = {0};
 944         int fd;
 945         struct stat st;
 946         size_t alloc_size;
 947         int n_th = 0;
 948         int is_self = 0;
 949
 950         if (!*name) {
 951                 errno = EINVAL;
 952                 return 0;
 953         }
 954
 955         /* Catch and block attempts to reload the implementation itself */
 956         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 957                 static const char reserved[] =
 958                         "c.pthread.rt.m.dl.util.xnet.";
 959                 const char *rp, *next;
 960                 for (rp=reserved; *rp; rp=next) {
 961                         next = strchr(rp, '.') + 1;
 962                         if (strncmp(name+3, rp, next-rp) == 0)
 963                                 break;
 964                 }
 965                 if (*rp) {
 966                         if (ldd_mode) {
 967                                 /* Track which names have been resolved
 968                                  * and only report each one once. */
 969                                 static unsigned reported;
 970                                 unsigned mask = 1U<<(rp-reserved);
 971                                 if (!(reported & mask)) {
 972                                         reported |= mask;
 973                                         dprintf(1, "\t%s => %s (%p)\n",
 974                                                 name, ldso.name,
 975                                                 ldso.base);
 976                                 }
 977                         }
 978                         is_self = 1;
 979                 }
 980         }
 981         if (!strcmp(name, ldso.name)) is_self = 1;
 982         if (is_self) {
 983                 if (!ldso.prev) {
 984                         tail->next = &ldso;
 985                         ldso.prev = tail;
 986                         tail = &ldso;
 987                 }
 988                 return &ldso;
 989         }
 990         if (strchr(name, '/')) {
 991                 pathname = name;
 992                 fd = open(name, O_RDONLY|O_CLOEXEC);
 993         } else {
 994                 /* Search for the name to see if it's already loaded */
 995                 for (p=head->next; p; p=p->next) {
 996                         if (p->shortname && !strcmp(p->shortname, name)) {
 997                                 return p;
 998                         }
 999                 }
1000                 if (strlen(name) > NAME_MAX) return 0;
1001                 fd = -1;
1002                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
1003                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
1004                         if (fixup_rpath(p, buf, sizeof buf) < 0)
1005                                 fd = -2; /* Inhibit further search. */
1006                         if (p->rpath)
1007                                 fd = path_open(name, p->rpath, buf, sizeof buf);
1008                 }
1009                 if (fd == -1) {
1010                         if (!sys_path) {
1011                                 char *prefix = 0;
1012                                 size_t prefix_len;
1013                                 if (ldso.name[0]=='/') {
1014                                         char *s, *t, *z;
1015                                         for (s=t=z=ldso.name; *s; s++)
1016                                                 if (*s=='/') z=t, t=s;
1017                                         prefix_len = z-ldso.name;
1018                                         if (prefix_len < PATH_MAX)
1019                                                 prefix = ldso.name;
1020                                 }
1021                                 if (!prefix) {
1022                                         prefix = "";
1023                                         prefix_len = 0;
1024                                 }
1025                                 char etc_ldso_path[prefix_len + 1
1026                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1027                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1028                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1029                                         (int)prefix_len, prefix);
1030                                 FILE *f = fopen(etc_ldso_path, "rbe");
1031                                 if (f) {
1032                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1033                                                 free(sys_path);
1034                                                 sys_path = "";
1035                                         }
1036                                         fclose(f);
1037                                 } else if (errno != ENOENT) {
1038                                         sys_path = "";
1039                                 }
1040                         }
1041                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1042                         fd = path_open(name, sys_path, buf, sizeof buf);
1043                 }
1044                 pathname = buf;
1045         }
1046         if (fd < 0) return 0;
1047         if (fstat(fd, &st) < 0) {
1048                 close(fd);
1049                 return 0;
1050         }
1051         for (p=head->next; p; p=p->next) {
1052                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1053                         /* If this library was previously loaded with a
1054                          * pathname but a search found the same inode,
1055                          * setup its shortname so it can be found by name. */
1056                         if (!p->shortname && pathname != name)
1057                                 p->shortname = strrchr(p->name, '/')+1;
1058                         close(fd);
1059                         return p;
1060                 }
1061         }
1062         map = noload ? 0 : map_library(fd, &temp_dso);
1063         close(fd);
1064         if (!map) return 0;
1065
1066         /* Avoid the danger of getting two versions of libc mapped into the
1067          * same process when an absolute pathname was used. The symbols
1068          * checked are chosen to catch both musl and glibc, and to avoid
1069          * false positives from interposition-hack libraries. */
1070         decode_dyn(&temp_dso);
1071         if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1072             find_sym(&temp_dso, "stdin", 1).sym) {
1073                 unmap_library(&temp_dso);
1074                 return load_library("libc.so", needed_by);
1075         }
1076         /* Past this point, if we haven't reached runtime yet, ldso has
1077          * committed either to use the mapped library or to abort execution.
1078          * Unmapping is not possible, so we can safely reclaim gaps. */
1079         if (!runtime) reclaim_gaps(&temp_dso);
1080
1081         /* Allocate storage for the new DSO. When there is TLS, this
1082          * storage must include a reservation for all pre-existing
1083          * threads to obtain copies of both the new TLS, and an
1084          * extended DTV capable of storing an additional slot for
1085          * the newly-loaded DSO. */
1086         alloc_size = sizeof *p + strlen(pathname) + 1;
1087         if (runtime && temp_dso.tls.image) {
1088                 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1089                         + sizeof(void *) * (tls_cnt+3);
1090                 n_th = libc.threads_minus_1 + 1;
1091                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1092                 else alloc_size += n_th * per_th;
1093         }
1094         p = calloc(1, alloc_size);
1095         if (!p) {
1096                 unmap_library(&temp_dso);
1097                 return 0;
1098         }
1099         memcpy(p, &temp_dso, sizeof temp_dso);
1100         p->dev = st.st_dev;
1101         p->ino = st.st_ino;
1102         p->needed_by = needed_by;
1103         p->name = p->buf;
1104         strcpy(p->name, pathname);
1105         /* Add a shortname only if name arg was not an explicit pathname. */
1106         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1107         if (p->tls.image) {
1108                 p->tls_id = ++tls_cnt;
1109                 tls_align = MAXP2(tls_align, p->tls.align);
1110 #ifdef TLS_ABOVE_TP
1111                 p->tls.offset = tls_offset + ( (tls_align-1) &
1112                         -(tls_offset + (uintptr_t)p->tls.image) );
1113                 tls_offset += p->tls.size;
1114 #else
1115                 tls_offset += p->tls.size + p->tls.align - 1;
1116                 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1117                         & (p->tls.align-1);
1118                 p->tls.offset = tls_offset;
1119 #endif
1120                 p->new_dtv = (void *)(-sizeof(size_t) &
1121                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1122                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1123                 if (tls_tail) tls_tail->next = &p->tls;
1124                 else libc.tls_head = &p->tls;
1125                 tls_tail = &p->tls;
1126         }
1127
1128         tail->next = p;
1129         p->prev = tail;
1130         tail = p;
1131
1132         if (DL_FDPIC) makefuncdescs(p);
1133
1134         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1135
1136         return p;
1137 }
1138
1139 static void load_deps(struct dso *p)
1140 {
1141         size_t i, ndeps=0;
1142         struct dso ***deps = &p->deps, **tmp, *dep;
1143         for (; p; p=p->next) {
1144                 for (i=0; p->dynv[i]; i+=2) {
1145                         if (p->dynv[i] != DT_NEEDED) continue;
1146                         dep = load_library(p->strings + p->dynv[i+1], p);
1147                         if (!dep) {
1148                                 error("Error loading shared library %s: %m (needed by %s)",
1149                                         p->strings + p->dynv[i+1], p->name);
1150                                 if (runtime) longjmp(*rtld_fail, 1);
1151                                 continue;
1152                         }
1153                         if (runtime) {
1154                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1155                                 if (!tmp) longjmp(*rtld_fail, 1);
1156                                 tmp[ndeps++] = dep;
1157                                 tmp[ndeps] = 0;
1158                                 *deps = tmp;
1159                         }
1160                 }
1161         }
1162         if (!*deps) *deps = (struct dso **)&nodeps_dummy;
1163 }
1164
1165 static void load_preload(char *s)
1166 {
1167         int tmp;
1168         char *z;
1169         for (z=s; *z; s=z) {
1170                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1171                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1172                 tmp = *z;
1173                 *z = 0;
1174                 load_library(s, 0);
1175                 *z = tmp;
1176         }
1177 }
1178
1179 static void add_syms(struct dso *p)
1180 {
1181         if (!p->syms_next && syms_tail != p) {
1182                 syms_tail->syms_next = p;
1183                 syms_tail = p;
1184         }
1185 }
1186
1187 static void revert_syms(struct dso *old_tail)
1188 {
1189         struct dso *p, *next;
1190         /* Chop off the tail of the list of dsos that participate in
1191          * the global symbol table, reverting them to RTLD_LOCAL. */
1192         for (p=old_tail; p; p=next) {
1193                 next = p->syms_next;
1194                 p->syms_next = 0;
1195         }
1196         syms_tail = old_tail;
1197 }
1198
1199 static void do_mips_relocs(struct dso *p, size_t *got)
1200 {
1201         size_t i, j, rel[2];
1202         unsigned char *base = p->base;
1203         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1204         if (p==&ldso) {
1205                 got += i;
1206         } else {
1207                 while (i--) *got++ += (size_t)base;
1208         }
1209         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1210         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1211         Sym *sym = p->syms + j;
1212         rel[0] = (unsigned char *)got - base;
1213         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1214                 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1215                 do_relocs(p, rel, sizeof rel, 2);
1216         }
1217 }
1218
1219 static void reloc_all(struct dso *p)
1220 {
1221         size_t dyn[DYN_CNT];
1222         for (; p; p=p->next) {
1223                 if (p->relocated) continue;
1224                 decode_vec(p->dynv, dyn, DYN_CNT);
1225                 if (NEED_MIPS_GOT_RELOCS)
1226                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1227                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1228                         2+(dyn[DT_PLTREL]==DT_RELA));
1229                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1230                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1231
1232                 if (head != &ldso && p->relro_start != p->relro_end &&
1233                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1234                     && errno != ENOSYS) {
1235                         error("Error relocating %s: RELRO protection failed: %m",
1236                                 p->name);
1237                         if (runtime) longjmp(*rtld_fail, 1);
1238                 }
1239
1240                 p->relocated = 1;
1241         }
1242 }
1243
1244 static void kernel_mapped_dso(struct dso *p)
1245 {
1246         size_t min_addr = -1, max_addr = 0, cnt;
1247         Phdr *ph = p->phdr;
1248         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1249                 if (ph->p_type == PT_DYNAMIC) {
1250                         p->dynv = laddr(p, ph->p_vaddr);
1251                 } else if (ph->p_type == PT_GNU_RELRO) {
1252                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1253                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1254                 }
1255                 if (ph->p_type != PT_LOAD) continue;
1256                 if (ph->p_vaddr < min_addr)
1257                         min_addr = ph->p_vaddr;
1258                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1259                         max_addr = ph->p_vaddr+ph->p_memsz;
1260         }
1261         min_addr &= -PAGE_SIZE;
1262         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1263         p->map = p->base + min_addr;
1264         p->map_len = max_addr - min_addr;
1265         p->kernel_mapped = 1;
1266 }
1267
1268 void __libc_exit_fini()
1269 {
1270         struct dso *p;
1271         size_t dyn[DYN_CNT];
1272         for (p=fini_head; p; p=p->fini_next) {
1273                 if (!p->constructed) continue;
1274                 decode_vec(p->dynv, dyn, DYN_CNT);
1275                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1276                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1277                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1278                         while (n--) ((void (*)(void))*--fn)();
1279                 }
1280 #ifndef NO_LEGACY_INITFINI
1281                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1282                         fpaddr(p, dyn[DT_FINI])();
1283 #endif
1284         }
1285 }
1286
1287 static void do_init_fini(struct dso *p)
1288 {
1289         size_t dyn[DYN_CNT];
1290         int need_locking = libc.threads_minus_1;
1291         /* Allow recursive calls that arise when a library calls
1292          * dlopen from one of its constructors, but block any
1293          * other threads until all ctors have finished. */
1294         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1295         for (; p; p=p->prev) {
1296                 if (p->constructed) continue;
1297                 p->constructed = 1;
1298                 decode_vec(p->dynv, dyn, DYN_CNT);
1299                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1300                         p->fini_next = fini_head;
1301                         fini_head = p;
1302                 }
1303 #ifndef NO_LEGACY_INITFINI
1304                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1305                         fpaddr(p, dyn[DT_INIT])();
1306 #endif
1307                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1308                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1309                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1310                         while (n--) ((void (*)(void))*fn++)();
1311                 }
1312                 if (!need_locking && libc.threads_minus_1) {
1313                         need_locking = 1;
1314                         pthread_mutex_lock(&init_fini_lock);
1315                 }
1316         }
1317         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1318 }
1319
1320 void __libc_start_init(void)
1321 {
1322         do_init_fini(tail);
1323 }
1324
1325 static void dl_debug_state(void)
1326 {
1327 }
1328
1329 weak_alias(dl_debug_state, _dl_debug_state);
1330
1331 void __init_tls(size_t *auxv)
1332 {
1333 }
1334
1335 __attribute__((__visibility__("hidden")))
1336 void *__tls_get_new(tls_mod_off_t *v)
1337 {
1338         pthread_t self = __pthread_self();
1339
1340         /* Block signals to make accessing new TLS async-signal-safe */
1341         sigset_t set;
1342         __block_all_sigs(&set);
1343         if (v[0]<=(size_t)self->dtv[0]) {
1344                 __restore_sigs(&set);
1345                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1346         }
1347
1348         /* This is safe without any locks held because, if the caller
1349          * is able to request the Nth entry of the DTV, the DSO list
1350          * must be valid at least that far out and it was synchronized
1351          * at program startup or by an already-completed call to dlopen. */
1352         struct dso *p;
1353         for (p=head; p->tls_id != v[0]; p=p->next);
1354
1355         /* Get new DTV space from new DSO if needed */
1356         if (v[0] > (size_t)self->dtv[0]) {
1357                 void **newdtv = p->new_dtv +
1358                         (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1359                 memcpy(newdtv, self->dtv,
1360                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1361                 newdtv[0] = (void *)v[0];
1362                 self->dtv = self->dtv_copy = newdtv;
1363         }
1364
1365         /* Get new TLS memory from all new DSOs up to the requested one */
1366         unsigned char *mem;
1367         for (p=head; ; p=p->next) {
1368                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1369                 mem = p->new_tls + (p->tls.size + p->tls.align)
1370                         * a_fetch_add(&p->new_tls_idx,1);
1371                 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1372                         & (p->tls.align-1);
1373                 self->dtv[p->tls_id] = mem;
1374                 memcpy(mem, p->tls.image, p->tls.len);
1375                 if (p->tls_id == v[0]) break;
1376         }
1377         __restore_sigs(&set);
1378         return mem + v[1] + DTP_OFFSET;
1379 }
1380
1381 static void update_tls_size()
1382 {
1383         libc.tls_cnt = tls_cnt;
1384         libc.tls_align = tls_align;
1385         libc.tls_size = ALIGN(
1386                 (1+tls_cnt) * sizeof(void *) +
1387                 tls_offset +
1388                 sizeof(struct pthread) +
1389                 tls_align * 2,
1390         tls_align);
1391 }
1392
1393 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1394  * following stage 2 and stage 3 functions via primitive symbolic lookup
1395  * since it does not have access to their addresses to begin with. */
1396
1397 /* Stage 2 of the dynamic linker is called after relative relocations
1398  * have been processed. It can make function calls to static functions
1399  * and access string literals and static data, but cannot use extern
1400  * symbols. Its job is to perform symbolic relocations on the dynamic
1401  * linker itself, but some of the relocations performed may need to be
1402  * replaced later due to copy relocations in the main program. */
1403
1404 __attribute__((__visibility__("hidden")))
1405 void __dls2(unsigned char *base, size_t *sp)
1406 {
1407         if (DL_FDPIC) {
1408                 void *p1 = (void *)sp[-2];
1409                 void *p2 = (void *)sp[-1];
1410                 if (!p1) {
1411                         size_t *auxv, aux[AUX_CNT];
1412                         for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1413                         decode_vec(auxv, aux, AUX_CNT);
1414                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1415                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1416                 }
1417                 app_loadmap = p2 ? p1 : 0;
1418                 ldso.loadmap = p2 ? p2 : p1;
1419                 ldso.base = laddr(&ldso, 0);
1420         } else {
1421                 ldso.base = base;
1422         }
1423         Ehdr *ehdr = (void *)ldso.base;
1424         ldso.name = ldso.shortname = "libc.so";
1425         ldso.phnum = ehdr->e_phnum;
1426         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1427         ldso.phentsize = ehdr->e_phentsize;
1428         kernel_mapped_dso(&ldso);
1429         decode_dyn(&ldso);
1430
1431         if (DL_FDPIC) makefuncdescs(&ldso);
1432
1433         /* Prepare storage for to save clobbered REL addends so they
1434          * can be reused in stage 3. There should be very few. If
1435          * something goes wrong and there are a huge number, abort
1436          * instead of risking stack overflow. */
1437         size_t dyn[DYN_CNT];
1438         decode_vec(ldso.dynv, dyn, DYN_CNT);
1439         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1440         size_t rel_size = dyn[DT_RELSZ];
1441         size_t symbolic_rel_cnt = 0;
1442         apply_addends_to = rel;
1443         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1444                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1445         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1446         size_t addends[symbolic_rel_cnt+1];
1447         saved_addends = addends;
1448
1449         head = &ldso;
1450         reloc_all(&ldso);
1451
1452         ldso.relocated = 0;
1453
1454         /* Call dynamic linker stage-3, __dls3, looking it up
1455          * symbolically as a barrier against moving the address
1456          * load across the above relocation processing. */
1457         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1458         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1459         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1460 }
1461
1462 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1463  * fully functional. Its job is to load (if not already loaded) and
1464  * process dependencies and relocations for the main application and
1465  * transfer control to its entry point. */
1466
1467 _Noreturn void __dls3(size_t *sp)
1468 {
1469         static struct dso app, vdso;
1470         size_t aux[AUX_CNT], *auxv;
1471         size_t i;
1472         char *env_preload=0;
1473         char *replace_argv0=0;
1474         size_t vdso_base;
1475         int argc = *sp;
1476         char **argv = (void *)(sp+1);
1477         char **argv_orig = argv;
1478         char **envp = argv+argc+1;
1479
1480         /* Find aux vector just past environ[] and use it to initialize
1481          * global data that may be needed before we can make syscalls. */
1482         __environ = envp;
1483         for (i=argc+1; argv[i]; i++);
1484         libc.auxv = auxv = (void *)(argv+i+1);
1485         decode_vec(auxv, aux, AUX_CNT);
1486         __hwcap = aux[AT_HWCAP];
1487         libc.page_size = aux[AT_PAGESZ];
1488         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1489                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1490
1491         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1492          * use during dynamic linking. If possible it will also serve as the
1493          * thread pointer at runtime. */
1494         libc.tls_size = sizeof builtin_tls;
1495         libc.tls_align = tls_align;
1496         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1497                 a_crash();
1498         }
1499
1500         /* Only trust user/env if kernel says we're not suid/sgid */
1501         if (!libc.secure) {
1502                 env_path = getenv("LD_LIBRARY_PATH");
1503                 env_preload = getenv("LD_PRELOAD");
1504         }
1505
1506         /* If the main program was already loaded by the kernel,
1507          * AT_PHDR will point to some location other than the dynamic
1508          * linker's program headers. */
1509         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1510                 size_t interp_off = 0;
1511                 size_t tls_image = 0;
1512                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1513                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1514                 app.phnum = aux[AT_PHNUM];
1515                 app.phentsize = aux[AT_PHENT];
1516                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1517                         if (phdr->p_type == PT_PHDR)
1518                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1519                         else if (phdr->p_type == PT_INTERP)
1520                                 interp_off = (size_t)phdr->p_vaddr;
1521                         else if (phdr->p_type == PT_TLS) {
1522                                 tls_image = phdr->p_vaddr;
1523                                 app.tls.len = phdr->p_filesz;
1524                                 app.tls.size = phdr->p_memsz;
1525                                 app.tls.align = phdr->p_align;
1526                         }
1527                 }
1528                 if (DL_FDPIC) app.loadmap = app_loadmap;
1529                 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1530                 if (interp_off) ldso.name = laddr(&app, interp_off);
1531                 if ((aux[0] & (1UL<<AT_EXECFN))
1532                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1533                         app.name = (char *)aux[AT_EXECFN];
1534                 else
1535                         app.name = argv[0];
1536                 kernel_mapped_dso(&app);
1537         } else {
1538                 int fd;
1539                 char *ldname = argv[0];
1540                 size_t l = strlen(ldname);
1541                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1542                 argv++;
1543                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1544                         char *opt = argv[0]+2;
1545                         *argv++ = (void *)-1;
1546                         if (!*opt) {
1547                                 break;
1548                         } else if (!memcmp(opt, "list", 5)) {
1549                                 ldd_mode = 1;
1550                         } else if (!memcmp(opt, "library-path", 12)) {
1551                                 if (opt[12]=='=') env_path = opt+13;
1552                                 else if (opt[12]) *argv = 0;
1553                                 else if (*argv) env_path = *argv++;
1554                         } else if (!memcmp(opt, "preload", 7)) {
1555                                 if (opt[7]=='=') env_preload = opt+8;
1556                                 else if (opt[7]) *argv = 0;
1557                                 else if (*argv) env_preload = *argv++;
1558                         } else if (!memcmp(opt, "argv0", 5)) {
1559                                 if (opt[5]=='=') replace_argv0 = opt+6;
1560                                 else if (opt[5]) *argv = 0;
1561                                 else if (*argv) replace_argv0 = *argv++;
1562                         } else {
1563                                 argv[0] = 0;
1564                         }
1565                 }
1566                 argv[-1] = (void *)(argc - (argv-argv_orig));
1567                 if (!argv[0]) {
1568                         dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1569                                 "Version %s\n"
1570                                 "Dynamic Program Loader\n"
1571                                 "Usage: %s [options] [--] pathname%s\n",
1572                                 __libc_get_version(), ldname,
1573                                 ldd_mode ? "" : " [args]");
1574                         _exit(1);
1575                 }
1576                 fd = open(argv[0], O_RDONLY);
1577                 if (fd < 0) {
1578                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1579                         _exit(1);
1580                 }
1581                 Ehdr *ehdr = (void *)map_library(fd, &app);
1582                 if (!ehdr) {
1583                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1584                         _exit(1);
1585                 }
1586                 close(fd);
1587                 ldso.name = ldname;
1588                 app.name = argv[0];
1589                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1590                 /* Find the name that would have been used for the dynamic
1591                  * linker had ldd not taken its place. */
1592                 if (ldd_mode) {
1593                         for (i=0; i<app.phnum; i++) {
1594                                 if (app.phdr[i].p_type == PT_INTERP)
1595                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1596                         }
1597                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1598                 }
1599         }
1600         if (app.tls.size) {
1601                 libc.tls_head = tls_tail = &app.tls;
1602                 app.tls_id = tls_cnt = 1;
1603 #ifdef TLS_ABOVE_TP
1604                 app.tls.offset = GAP_ABOVE_TP;
1605                 app.tls.offset += -GAP_ABOVE_TP & (app.tls.align-1);
1606                 tls_offset = app.tls.offset + app.tls.size
1607                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1608                         & (app.tls.align-1) );
1609 #else
1610                 tls_offset = app.tls.offset = app.tls.size
1611                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1612                         & (app.tls.align-1) );
1613 #endif
1614                 tls_align = MAXP2(tls_align, app.tls.align);
1615         }
1616         decode_dyn(&app);
1617         if (DL_FDPIC) {
1618                 makefuncdescs(&app);
1619                 if (!app.loadmap) {
1620                         app.loadmap = (void *)&app_dummy_loadmap;
1621                         app.loadmap->nsegs = 1;
1622                         app.loadmap->segs[0].addr = (size_t)app.map;
1623                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1624                                 - (size_t)app.base;
1625                         app.loadmap->segs[0].p_memsz = app.map_len;
1626                 }
1627                 argv[-3] = (void *)app.loadmap;
1628         }
1629
1630         /* Initial dso chain consists only of the app. */
1631         head = tail = syms_tail = &app;
1632
1633         /* Donate unused parts of app and library mapping to malloc */
1634         reclaim_gaps(&app);
1635         reclaim_gaps(&ldso);
1636
1637         /* Load preload/needed libraries, add symbols to global namespace. */
1638         if (env_preload) load_preload(env_preload);
1639         load_deps(&app);
1640         for (struct dso *p=head; p; p=p->next)
1641                 add_syms(p);
1642
1643         /* Attach to vdso, if provided by the kernel, last so that it does
1644          * not become part of the global namespace.  */
1645         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1646                 Ehdr *ehdr = (void *)vdso_base;
1647                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1648                 vdso.phnum = ehdr->e_phnum;
1649                 vdso.phentsize = ehdr->e_phentsize;
1650                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1651                         if (phdr->p_type == PT_DYNAMIC)
1652                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1653                         if (phdr->p_type == PT_LOAD)
1654                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1655                 }
1656                 vdso.name = "";
1657                 vdso.shortname = "linux-gate.so.1";
1658                 vdso.relocated = 1;
1659                 decode_dyn(&vdso);
1660                 vdso.prev = tail;
1661                 tail->next = &vdso;
1662                 tail = &vdso;
1663         }
1664
1665         for (i=0; app.dynv[i]; i+=2) {
1666                 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1667                         app.dynv[i+1] = (size_t)&debug;
1668                 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1669                         size_t *ptr = (size_t *) app.dynv[i+1];
1670                         *ptr = (size_t)&debug;
1671                 }
1672         }
1673
1674         /* The main program must be relocated LAST since it may contin
1675          * copy relocations which depend on libraries' relocations. */
1676         reloc_all(app.next);
1677         reloc_all(&app);
1678
1679         update_tls_size();
1680         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1681                 void *initial_tls = calloc(libc.tls_size, 1);
1682                 if (!initial_tls) {
1683                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1684                                 argv[0], libc.tls_size);
1685                         _exit(127);
1686                 }
1687                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1688                         a_crash();
1689                 }
1690         } else {
1691                 size_t tmp_tls_size = libc.tls_size;
1692                 pthread_t self = __pthread_self();
1693                 /* Temporarily set the tls size to the full size of
1694                  * builtin_tls so that __copy_tls will use the same layout
1695                  * as it did for before. Then check, just to be safe. */
1696                 libc.tls_size = sizeof builtin_tls;
1697                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1698                 libc.tls_size = tmp_tls_size;
1699         }
1700         static_tls_cnt = tls_cnt;
1701
1702         if (ldso_fail) _exit(127);
1703         if (ldd_mode) _exit(0);
1704
1705         /* Determine if malloc was interposed by a replacement implementation
1706          * so that calloc and the memalign family can harden against the
1707          * possibility of incomplete replacement. */
1708         if (find_sym(head, "malloc", 1).dso != &ldso)
1709                 __malloc_replaced = 1;
1710
1711         /* Switch to runtime mode: any further failures in the dynamic
1712          * linker are a reportable failure rather than a fatal startup
1713          * error. */
1714         runtime = 1;
1715
1716         debug.ver = 1;
1717         debug.bp = dl_debug_state;
1718         debug.head = head;
1719         debug.base = ldso.base;
1720         debug.state = 0;
1721         _dl_debug_state();
1722
1723         if (replace_argv0) argv[0] = replace_argv0;
1724
1725         errno = 0;
1726
1727         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1728         for(;;);
1729 }
1730
1731 static void prepare_lazy(struct dso *p)
1732 {
1733         size_t dyn[DYN_CNT], n, flags1=0;
1734         decode_vec(p->dynv, dyn, DYN_CNT);
1735         search_vec(p->dynv, &flags1, DT_FLAGS_1);
1736         if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1737                 return;
1738         n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1739         if (NEED_MIPS_GOT_RELOCS) {
1740                 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1741                 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1742                 n += i-j;
1743         }
1744         p->lazy = calloc(n, 3*sizeof(size_t));
1745         if (!p->lazy) {
1746                 error("Error preparing lazy relocation for %s: %m", p->name);
1747                 longjmp(*rtld_fail, 1);
1748         }
1749         p->lazy_next = lazy_head;
1750         lazy_head = p;
1751 }
1752
1753 void *dlopen(const char *file, int mode)
1754 {
1755         struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1756         struct tls_module *orig_tls_tail;
1757         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1758         size_t i;
1759         int cs;
1760         jmp_buf jb;
1761
1762         if (!file) return head;
1763
1764         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1765         pthread_rwlock_wrlock(&lock);
1766         __inhibit_ptc();
1767
1768         p = 0;
1769         orig_tls_tail = tls_tail;
1770         orig_tls_cnt = tls_cnt;
1771         orig_tls_offset = tls_offset;
1772         orig_tls_align = tls_align;
1773         orig_lazy_head = lazy_head;
1774         orig_syms_tail = syms_tail;
1775         orig_tail = tail;
1776         noload = mode & RTLD_NOLOAD;
1777
1778         rtld_fail = &jb;
1779         if (setjmp(*rtld_fail)) {
1780                 /* Clean up anything new that was (partially) loaded */
1781                 revert_syms(orig_syms_tail);
1782                 for (p=orig_tail->next; p; p=next) {
1783                         next = p->next;
1784                         while (p->td_index) {
1785                                 void *tmp = p->td_index->next;
1786                                 free(p->td_index);
1787                                 p->td_index = tmp;
1788                         }
1789                         free(p->funcdescs);
1790                         if (p->rpath != p->rpath_orig)
1791                                 free(p->rpath);
1792                         if (p->deps != &nodeps_dummy)
1793                                 free(p->deps);
1794                         unmap_library(p);
1795                         free(p);
1796                 }
1797                 if (!orig_tls_tail) libc.tls_head = 0;
1798                 tls_tail = orig_tls_tail;
1799                 if (tls_tail) tls_tail->next = 0;
1800                 tls_cnt = orig_tls_cnt;
1801                 tls_offset = orig_tls_offset;
1802                 tls_align = orig_tls_align;
1803                 lazy_head = orig_lazy_head;
1804                 tail = orig_tail;
1805                 tail->next = 0;
1806                 p = 0;
1807                 goto end;
1808         } else p = load_library(file, head);
1809
1810         if (!p) {
1811                 error(noload ?
1812                         "Library %s is not already loaded" :
1813                         "Error loading shared library %s: %m",
1814                         file);
1815                 goto end;
1816         }
1817
1818         /* First load handling */
1819         int first_load = !p->deps;
1820         if (first_load) {
1821                 load_deps(p);
1822                 if (!p->relocated && (mode & RTLD_LAZY)) {
1823                         prepare_lazy(p);
1824                         for (i=0; p->deps[i]; i++)
1825                                 if (!p->deps[i]->relocated)
1826                                         prepare_lazy(p->deps[i]);
1827                 }
1828         }
1829         if (first_load || (mode & RTLD_GLOBAL)) {
1830                 /* Make new symbols global, at least temporarily, so we can do
1831                  * relocations. If not RTLD_GLOBAL, this is reverted below. */
1832                 add_syms(p);
1833                 for (i=0; p->deps[i]; i++)
1834                         add_syms(p->deps[i]);
1835         }
1836         if (first_load) {
1837                 reloc_all(p);
1838         }
1839
1840         /* If RTLD_GLOBAL was not specified, undo any new additions
1841          * to the global symbol table. This is a nop if the library was
1842          * previously loaded and already global. */
1843         if (!(mode & RTLD_GLOBAL))
1844                 revert_syms(orig_syms_tail);
1845
1846         /* Processing of deferred lazy relocations must not happen until
1847          * the new libraries are committed; otherwise we could end up with
1848          * relocations resolved to symbol definitions that get removed. */
1849         redo_lazy_relocs();
1850
1851         update_tls_size();
1852         _dl_debug_state();
1853         orig_tail = tail;
1854 end:
1855         __release_ptc();
1856         if (p) gencnt++;
1857         pthread_rwlock_unlock(&lock);
1858         if (p) do_init_fini(orig_tail);
1859         pthread_setcancelstate(cs, 0);
1860         return p;
1861 }
1862
1863 __attribute__((__visibility__("hidden")))
1864 int __dl_invalid_handle(void *h)
1865 {
1866         struct dso *p;
1867         for (p=head; p; p=p->next) if (h==p) return 0;
1868         error("Invalid library handle %p", (void *)h);
1869         return 1;
1870 }
1871
1872 static void *addr2dso(size_t a)
1873 {
1874         struct dso *p;
1875         size_t i;
1876         if (DL_FDPIC) for (p=head; p; p=p->next) {
1877                 i = count_syms(p);
1878                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1879                         return p;
1880         }
1881         for (p=head; p; p=p->next) {
1882                 if (DL_FDPIC && p->loadmap) {
1883                         for (i=0; i<p->loadmap->nsegs; i++) {
1884                                 if (a-p->loadmap->segs[i].p_vaddr
1885                                     < p->loadmap->segs[i].p_memsz)
1886                                         return p;
1887                         }
1888                 } else {
1889                         Phdr *ph = p->phdr;
1890                         size_t phcnt = p->phnum;
1891                         size_t entsz = p->phentsize;
1892                         size_t base = (size_t)p->base;
1893                         for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
1894                                 if (ph->p_type != PT_LOAD) continue;
1895                                 if (a-base-ph->p_vaddr < ph->p_memsz)
1896                                         return p;
1897                         }
1898                         if (a-(size_t)p->map < p->map_len)
1899                                 return 0;
1900                 }
1901         }
1902         return 0;
1903 }
1904
1905 void *__tls_get_addr(tls_mod_off_t *);
1906
1907 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1908 {
1909         size_t i;
1910         uint32_t h = 0, gh = 0, *ght;
1911         Sym *sym;
1912         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1913                 if (p == RTLD_DEFAULT) {
1914                         p = head;
1915                 } else if (p == RTLD_NEXT) {
1916                         p = addr2dso((size_t)ra);
1917                         if (!p) p=head;
1918                         p = p->next;
1919                 }
1920                 struct symdef def = find_sym(p, s, 0);
1921                 if (!def.sym) goto failed;
1922                 if ((def.sym->st_info&0xf) == STT_TLS)
1923                         return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
1924                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1925                         return def.dso->funcdescs + (def.sym - def.dso->syms);
1926                 return laddr(def.dso, def.sym->st_value);
1927         }
1928         if (__dl_invalid_handle(p))
1929                 return 0;
1930         if ((ght = p->ghashtab)) {
1931                 gh = gnu_hash(s);
1932                 sym = gnu_lookup(gh, ght, p, s);
1933         } else {
1934                 h = sysv_hash(s);
1935                 sym = sysv_lookup(s, h, p);
1936         }
1937         if (sym && (sym->st_info&0xf) == STT_TLS)
1938                 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
1939         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1940                 return p->funcdescs + (sym - p->syms);
1941         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1942                 return laddr(p, sym->st_value);
1943         for (i=0; p->deps[i]; i++) {
1944                 if ((ght = p->deps[i]->ghashtab)) {
1945                         if (!gh) gh = gnu_hash(s);
1946                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1947                 } else {
1948                         if (!h) h = sysv_hash(s);
1949                         sym = sysv_lookup(s, h, p->deps[i]);
1950                 }
1951                 if (sym && (sym->st_info&0xf) == STT_TLS)
1952                         return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
1953                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1954                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1955                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1956                         return laddr(p->deps[i], sym->st_value);
1957         }
1958 failed:
1959         error("Symbol not found: %s", s);
1960         return 0;
1961 }
1962
1963 int dladdr(const void *addr_arg, Dl_info *info)
1964 {
1965         size_t addr = (size_t)addr_arg;
1966         struct dso *p;
1967         Sym *sym, *bestsym;
1968         uint32_t nsym;
1969         char *strings;
1970         size_t best = 0;
1971         size_t besterr = -1;
1972
1973         pthread_rwlock_rdlock(&lock);
1974         p = addr2dso(addr);
1975         pthread_rwlock_unlock(&lock);
1976
1977         if (!p) return 0;
1978
1979         sym = p->syms;
1980         strings = p->strings;
1981         nsym = count_syms(p);
1982
1983         if (DL_FDPIC) {
1984                 size_t idx = (addr-(size_t)p->funcdescs)
1985                         / sizeof(*p->funcdescs);
1986                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1987                         best = (size_t)(p->funcdescs + idx);
1988                         bestsym = sym + idx;
1989                         besterr = 0;
1990                 }
1991         }
1992
1993         if (!best) for (; nsym; nsym--, sym++) {
1994                 if (sym->st_value
1995                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1996                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1997                         size_t symaddr = (size_t)laddr(p, sym->st_value);
1998                         if (symaddr > addr || symaddr <= best)
1999                                 continue;
2000                         best = symaddr;
2001                         bestsym = sym;
2002                         besterr = addr - symaddr;
2003                         if (addr == symaddr)
2004                                 break;
2005                 }
2006         }
2007
2008         if (bestsym && besterr > bestsym->st_size-1) {
2009                 best = 0;
2010                 bestsym = 0;
2011         }
2012
2013         info->dli_fname = p->name;
2014         info->dli_fbase = p->map;
2015
2016         if (!best) {
2017                 info->dli_sname = 0;
2018                 info->dli_saddr = 0;
2019                 return 1;
2020         }
2021
2022         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2023                 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2024         info->dli_sname = strings + bestsym->st_name;
2025         info->dli_saddr = (void *)best;
2026
2027         return 1;
2028 }
2029
2030 __attribute__((__visibility__("hidden")))
2031 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2032 {
2033         void *res;
2034         pthread_rwlock_rdlock(&lock);
2035         res = do_dlsym(p, s, ra);
2036         pthread_rwlock_unlock(&lock);
2037         return res;
2038 }
2039
2040 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2041 {
2042         struct dso *current;
2043         struct dl_phdr_info info;
2044         int ret = 0;
2045         for(current = head; current;) {
2046                 info.dlpi_addr      = (uintptr_t)current->base;
2047                 info.dlpi_name      = current->name;
2048                 info.dlpi_phdr      = current->phdr;
2049                 info.dlpi_phnum     = current->phnum;
2050                 info.dlpi_adds      = gencnt;
2051                 info.dlpi_subs      = 0;
2052                 info.dlpi_tls_modid = current->tls_id;
2053                 info.dlpi_tls_data  = current->tls.image;
2054
2055                 ret = (callback)(&info, sizeof (info), data);
2056
2057                 if (ret != 0) break;
2058
2059                 pthread_rwlock_rdlock(&lock);
2060                 current = current->next;
2061                 pthread_rwlock_unlock(&lock);
2062         }
2063         return ret;
2064 }
2065
2066 __attribute__((__visibility__("hidden")))
2067 void __dl_vseterr(const char *, va_list);
2068
2069 static void error(const char *fmt, ...)
2070 {
2071         va_list ap;
2072         va_start(ap, fmt);
2073         if (!runtime) {
2074                 vdprintf(2, fmt, ap);
2075                 dprintf(2, "\n");
2076                 ldso_fail = 1;
2077                 va_end(ap);
2078                 return;
2079         }
2080         __dl_vseterr(fmt, ap);
2081         va_end(ap);
2082 }