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