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