ldso/dynlink.c

   1 #define _GNU_SOURCE
   2 #define SYSCALL_NO_TLS 1
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <stdarg.h>
   6 #include <stddef.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9 #include <stdint.h>
  10 #include <elf.h>
  11 #include <sys/mman.h>
  12 #include <limits.h>
  13 #include <fcntl.h>
  14 #include <sys/stat.h>
  15 #include <errno.h>
  16 #include <link.h>
  17 #include <setjmp.h>
  18 #include <pthread.h>
  19 #include <ctype.h>
  20 #include <dlfcn.h>
  21 #include <semaphore.h>
  22 #include <sys/membarrier.h>
  23 #include "pthread_impl.h"
  24 #include "libc.h"
  25 #include "dynlink.h"
  26 #include "malloc_impl.h"
  27
  28 static void error(const char *, ...);
  29
  30 #define MAXP2(a,b) (-(-(a)&-(b)))
  31 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  32
  33 #define container_of(p,t,m) ((t*)((char *)(p)-offsetof(t,m)))
  34 #define countof(a) ((sizeof (a))/(sizeof (a)[0]))
  35
  36 struct debug {
  37         int ver;
  38         void *head;
  39         void (*bp)(void);
  40         int state;
  41         void *base;
  42 };
  43
  44 struct td_index {
  45         size_t args[2];
  46         struct td_index *next;
  47 };
  48
  49 struct dso {
  50 #if DL_FDPIC
  51         struct fdpic_loadmap *loadmap;
  52 #else
  53         unsigned char *base;
  54 #endif
  55         char *name;
  56         size_t *dynv;
  57         struct dso *next, *prev;
  58
  59         Phdr *phdr;
  60         int phnum;
  61         size_t phentsize;
  62         Sym *syms;
  63         Elf_Symndx *hashtab;
  64         uint32_t *ghashtab;
  65         int16_t *versym;
  66         char *strings;
  67         struct dso *syms_next, *lazy_next;
  68         size_t *lazy, lazy_cnt;
  69         unsigned char *map;
  70         size_t map_len;
  71         dev_t dev;
  72         ino_t ino;
  73         char relocated;
  74         char constructed;
  75         char kernel_mapped;
  76         char mark;
  77         char bfs_built;
  78         char runtime_loaded;
  79         struct dso **deps, *needed_by;
  80         size_t ndeps_direct;
  81         size_t next_dep;
  82         int ctor_visitor;
  83         char *rpath_orig, *rpath;
  84         struct tls_module tls;
  85         size_t tls_id;
  86         size_t relro_start, relro_end;
  87         uintptr_t *new_dtv;
  88         unsigned char *new_tls;
  89         struct td_index *td_index;
  90         struct dso *fini_next;
  91         char *shortname;
  92 #if DL_FDPIC
  93         unsigned char *base;
  94 #else
  95         struct fdpic_loadmap *loadmap;
  96 #endif
  97         struct funcdesc {
  98                 void *addr;
  99                 size_t *got;
 100         } *funcdescs;
 101         size_t *got;
 102         char buf[];
 103 };
 104
 105 struct symdef {
 106         Sym *sym;
 107         struct dso *dso;
 108 };
 109
 110 static struct builtin_tls {
 111         char c;
 112         struct pthread pt;
 113         void *space[16];
 114 } builtin_tls[1];
 115 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 116
 117 #define ADDEND_LIMIT 4096
 118 static size_t *saved_addends, *apply_addends_to;
 119
 120 static struct dso ldso;
 121 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
 122 static char *env_path, *sys_path;
 123 static unsigned long long gencnt;
 124 static int runtime;
 125 static int ldd_mode;
 126 static int ldso_fail;
 127 static int noload;
 128 static int shutting_down;
 129 static jmp_buf *rtld_fail;
 130 static pthread_rwlock_t lock;
 131 static struct debug debug;
 132 static struct tls_module *tls_tail;
 133 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
 134 static size_t static_tls_cnt;
 135 static pthread_mutex_t init_fini_lock;
 136 static pthread_cond_t ctor_cond;
 137 static struct dso *builtin_deps[2];
 138 static struct dso *const no_deps[1];
 139 static struct dso *builtin_ctor_queue[4];
 140 static struct dso **main_ctor_queue;
 141 static struct fdpic_loadmap *app_loadmap;
 142 static struct fdpic_dummy_loadmap app_dummy_loadmap;
 143
 144 struct debug *_dl_debug_addr = &debug;
 145
 146 extern hidden int __malloc_replaced;
 147
 148 hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
 149
 150 extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
 151
 152 weak_alias(__init_array_start, __init_array_end);
 153 weak_alias(__fini_array_start, __fini_array_end);
 154
 155 static int dl_strcmp(const char *l, const char *r)
 156 {
 157         for (; *l==*r && *l; l++, r++);
 158         return *(unsigned char *)l - *(unsigned char *)r;
 159 }
 160 #define strcmp(l,r) dl_strcmp(l,r)
 161
 162 /* Compute load address for a virtual address in a given dso. */
 163 #if DL_FDPIC
 164 static void *laddr(const struct dso *p, size_t v)
 165 {
 166         size_t j=0;
 167         if (!p->loadmap) return p->base + v;
 168         for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
 169         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 170 }
 171 static void *laddr_pg(const struct dso *p, size_t v)
 172 {
 173         size_t j=0;
 174         size_t pgsz = PAGE_SIZE;
 175         if (!p->loadmap) return p->base + v;
 176         for (j=0; ; j++) {
 177                 size_t a = p->loadmap->segs[j].p_vaddr;
 178                 size_t b = a + p->loadmap->segs[j].p_memsz;
 179                 a &= -pgsz;
 180                 b += pgsz-1;
 181                 b &= -pgsz;
 182                 if (v-a<b-a) break;
 183         }
 184         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 185 }
 186 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
 187         laddr(p, v), (p)->got })
 188 #else
 189 #define laddr(p, v) (void *)((p)->base + (v))
 190 #define laddr_pg(p, v) laddr(p, v)
 191 #define fpaddr(p, v) ((void (*)())laddr(p, v))
 192 #endif
 193
 194 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 195 {
 196         size_t i;
 197         for (i=0; i<cnt; i++) a[i] = 0;
 198         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 199                 a[0] |= 1UL<<v[0];
 200                 a[v[0]] = v[1];
 201         }
 202 }
 203
 204 static int search_vec(size_t *v, size_t *r, size_t key)
 205 {
 206         for (; v[0]!=key; v+=2)
 207                 if (!v[0]) return 0;
 208         *r = v[1];
 209         return 1;
 210 }
 211
 212 static uint32_t sysv_hash(const char *s0)
 213 {
 214         const unsigned char *s = (void *)s0;
 215         uint_fast32_t h = 0;
 216         while (*s) {
 217                 h = 16*h + *s++;
 218                 h ^= h>>24 & 0xf0;
 219         }
 220         return h & 0xfffffff;
 221 }
 222
 223 static uint32_t gnu_hash(const char *s0)
 224 {
 225         const unsigned char *s = (void *)s0;
 226         uint_fast32_t h = 5381;
 227         for (; *s; s++)
 228                 h += h*32 + *s;
 229         return h;
 230 }
 231
 232 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 233 {
 234         size_t i;
 235         Sym *syms = dso->syms;
 236         Elf_Symndx *hashtab = dso->hashtab;
 237         char *strings = dso->strings;
 238         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 239                 if ((!dso->versym || dso->versym[i] >= 0)
 240                     && (!strcmp(s, strings+syms[i].st_name)))
 241                         return syms+i;
 242         }
 243         return 0;
 244 }
 245
 246 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 247 {
 248         uint32_t nbuckets = hashtab[0];
 249         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 250         uint32_t i = buckets[h1 % nbuckets];
 251
 252         if (!i) return 0;
 253
 254         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 255
 256         for (h1 |= 1; ; i++) {
 257                 uint32_t h2 = *hashval++;
 258                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 259                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 260                         return dso->syms+i;
 261                 if (h2 & 1) break;
 262         }
 263
 264         return 0;
 265 }
 266
 267 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 268 {
 269         const size_t *bloomwords = (const void *)(hashtab+4);
 270         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 271         if (!(f & fmask)) return 0;
 272
 273         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 274         if (!(f & 1)) return 0;
 275
 276         return gnu_lookup(h1, hashtab, dso, s);
 277 }
 278
 279 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 280 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 281
 282 #ifndef ARCH_SYM_REJECT_UND
 283 #define ARCH_SYM_REJECT_UND(s) 0
 284 #endif
 285
 286 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 287 {
 288         uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
 289         size_t ghm = 1ul << gh % (8*sizeof(size_t));
 290         struct symdef def = {0};
 291         for (; dso; dso=dso->syms_next) {
 292                 Sym *sym;
 293                 if ((ght = dso->ghashtab)) {
 294                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 295                 } else {
 296                         if (!h) h = sysv_hash(s);
 297                         sym = sysv_lookup(s, h, dso);
 298                 }
 299                 if (!sym) continue;
 300                 if (!sym->st_shndx)
 301                         if (need_def || (sym->st_info&0xf) == STT_TLS
 302                             || ARCH_SYM_REJECT_UND(sym))
 303                                 continue;
 304                 if (!sym->st_value)
 305                         if ((sym->st_info&0xf) != STT_TLS)
 306                                 continue;
 307                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 308                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 309                 def.sym = sym;
 310                 def.dso = dso;
 311                 break;
 312         }
 313         return def;
 314 }
 315
 316 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 317 {
 318         unsigned char *base = dso->base;
 319         Sym *syms = dso->syms;
 320         char *strings = dso->strings;
 321         Sym *sym;
 322         const char *name;
 323         void *ctx;
 324         int type;
 325         int sym_index;
 326         struct symdef def;
 327         size_t *reloc_addr;
 328         size_t sym_val;
 329         size_t tls_val;
 330         size_t addend;
 331         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 332
 333         if (dso == &ldso) {
 334                 /* Only ldso's REL table needs addend saving/reuse. */
 335                 if (rel == apply_addends_to)
 336                         reuse_addends = 1;
 337                 skip_relative = 1;
 338         }
 339
 340         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 341                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 342                 type = R_TYPE(rel[1]);
 343                 if (type == REL_NONE) continue;
 344                 reloc_addr = laddr(dso, rel[0]);
 345
 346                 if (stride > 2) {
 347                         addend = rel[2];
 348                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 349                         addend = 0;
 350                 } else if (reuse_addends) {
 351                         /* Save original addend in stage 2 where the dso
 352                          * chain consists of just ldso; otherwise read back
 353                          * saved addend since the inline one was clobbered. */
 354                         if (head==&ldso)
 355                                 saved_addends[save_slot] = *reloc_addr;
 356                         addend = saved_addends[save_slot++];
 357                 } else {
 358                         addend = *reloc_addr;
 359                 }
 360
 361                 sym_index = R_SYM(rel[1]);
 362                 if (sym_index) {
 363                         sym = syms + sym_index;
 364                         name = strings + sym->st_name;
 365                         ctx = type==REL_COPY ? head->syms_next : head;
 366                         def = (sym->st_info&0xf) == STT_SECTION
 367                                 ? (struct symdef){ .dso = dso, .sym = sym }
 368                                 : find_sym(ctx, name, type==REL_PLT);
 369                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 370                             || sym->st_info>>4 != STB_WEAK)) {
 371                                 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
 372                                         dso->lazy[3*dso->lazy_cnt+0] = rel[0];
 373                                         dso->lazy[3*dso->lazy_cnt+1] = rel[1];
 374                                         dso->lazy[3*dso->lazy_cnt+2] = addend;
 375                                         dso->lazy_cnt++;
 376                                         continue;
 377                                 }
 378                                 error("Error relocating %s: %s: symbol not found",
 379                                         dso->name, name);
 380                                 if (runtime) longjmp(*rtld_fail, 1);
 381                                 continue;
 382                         }
 383                 } else {
 384                         sym = 0;
 385                         def.sym = 0;
 386                         def.dso = dso;
 387                 }
 388
 389                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 390                 tls_val = def.sym ? def.sym->st_value : 0;
 391
 392                 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
 393                     && runtime && def.dso->tls_id > static_tls_cnt) {
 394                         error("Error relocating %s: %s: initial-exec TLS "
 395                                 "resolves to dynamic definition in %s",
 396                                 dso->name, name, def.dso->name);
 397                         longjmp(*rtld_fail, 1);
 398                 }
 399
 400                 switch(type) {
 401                 case REL_NONE:
 402                         break;
 403                 case REL_OFFSET:
 404                         addend -= (size_t)reloc_addr;
 405                 case REL_SYMBOLIC:
 406                 case REL_GOT:
 407                 case REL_PLT:
 408                         *reloc_addr = sym_val + addend;
 409                         break;
 410                 case REL_RELATIVE:
 411                         *reloc_addr = (size_t)base + addend;
 412                         break;
 413                 case REL_SYM_OR_REL:
 414                         if (sym) *reloc_addr = sym_val + addend;
 415                         else *reloc_addr = (size_t)base + addend;
 416                         break;
 417                 case REL_COPY:
 418                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 419                         break;
 420                 case REL_OFFSET32:
 421                         *(uint32_t *)reloc_addr = sym_val + addend
 422                                 - (size_t)reloc_addr;
 423                         break;
 424                 case REL_FUNCDESC:
 425                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 426                                 + (def.sym - def.dso->syms)) : 0;
 427                         break;
 428                 case REL_FUNCDESC_VAL:
 429                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 430                         else *reloc_addr = sym_val;
 431                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 432                         break;
 433                 case REL_DTPMOD:
 434                         *reloc_addr = def.dso->tls_id;
 435                         break;
 436                 case REL_DTPOFF:
 437                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 438                         break;
 439 #ifdef TLS_ABOVE_TP
 440                 case REL_TPOFF:
 441                         *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
 442                         break;
 443 #else
 444                 case REL_TPOFF:
 445                         *reloc_addr = tls_val - def.dso->tls.offset + addend;
 446                         break;
 447                 case REL_TPOFF_NEG:
 448                         *reloc_addr = def.dso->tls.offset - tls_val + addend;
 449                         break;
 450 #endif
 451                 case REL_TLSDESC:
 452                         if (stride<3) addend = reloc_addr[1];
 453                         if (runtime && def.dso->tls_id > static_tls_cnt) {
 454                                 struct td_index *new = malloc(sizeof *new);
 455                                 if (!new) {
 456                                         error(
 457                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 458                                         dso->name, sym ? name : "(local)" );
 459                                         longjmp(*rtld_fail, 1);
 460                                 }
 461                                 new->next = dso->td_index;
 462                                 dso->td_index = new;
 463                                 new->args[0] = def.dso->tls_id;
 464                                 new->args[1] = tls_val + addend - DTP_OFFSET;
 465                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 466                                 reloc_addr[1] = (size_t)new;
 467                         } else {
 468                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 469 #ifdef TLS_ABOVE_TP
 470                                 reloc_addr[1] = tls_val + def.dso->tls.offset
 471                                         + TPOFF_K + addend;
 472 #else
 473                                 reloc_addr[1] = tls_val - def.dso->tls.offset
 474                                         + addend;
 475 #endif
 476                         }
 477 #ifdef TLSDESC_BACKWARDS
 478                         /* Some archs (32-bit ARM at least) invert the order of
 479                          * the descriptor members. Fix them up here. */
 480                         size_t tmp = reloc_addr[0];
 481                         reloc_addr[0] = reloc_addr[1];
 482                         reloc_addr[1] = tmp;
 483 #endif
 484                         break;
 485                 default:
 486                         error("Error relocating %s: unsupported relocation type %d",
 487                                 dso->name, type);
 488                         if (runtime) longjmp(*rtld_fail, 1);
 489                         continue;
 490                 }
 491         }
 492 }
 493
 494 static void redo_lazy_relocs()
 495 {
 496         struct dso *p = lazy_head, *next;
 497         lazy_head = 0;
 498         for (; p; p=next) {
 499                 next = p->lazy_next;
 500                 size_t size = p->lazy_cnt*3*sizeof(size_t);
 501                 p->lazy_cnt = 0;
 502                 do_relocs(p, p->lazy, size, 3);
 503                 if (p->lazy_cnt) {
 504                         p->lazy_next = lazy_head;
 505                         lazy_head = p;
 506                 } else {
 507                         free(p->lazy);
 508                         p->lazy = 0;
 509                         p->lazy_next = 0;
 510                 }
 511         }
 512 }
 513
 514 /* A huge hack: to make up for the wastefulness of shared libraries
 515  * needing at least a page of dirty memory even if they have no global
 516  * data, we reclaim the gaps at the beginning and end of writable maps
 517  * and "donate" them to the heap. */
 518
 519 static void reclaim(struct dso *dso, size_t start, size_t end)
 520 {
 521         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 522         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 523         if (start >= end) return;
 524         char *base = laddr_pg(dso, start);
 525         __malloc_donate(base, base+(end-start));
 526 }
 527
 528 static void reclaim_gaps(struct dso *dso)
 529 {
 530         Phdr *ph = dso->phdr;
 531         size_t phcnt = dso->phnum;
 532
 533         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 534                 if (ph->p_type!=PT_LOAD) continue;
 535                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 536                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 537                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 538                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 539         }
 540 }
 541
 542 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 543 {
 544         static int no_map_fixed;
 545         char *q;
 546         if (!no_map_fixed) {
 547                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 548                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 549                         return q;
 550                 no_map_fixed = 1;
 551         }
 552         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 553         if (flags & MAP_ANONYMOUS) {
 554                 memset(p, 0, n);
 555                 return p;
 556         }
 557         ssize_t r;
 558         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 559         for (q=p; n; q+=r, off+=r, n-=r) {
 560                 r = read(fd, q, n);
 561                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 562                 if (!r) {
 563                         memset(q, 0, n);
 564                         break;
 565                 }
 566         }
 567         return p;
 568 }
 569
 570 static void unmap_library(struct dso *dso)
 571 {
 572         if (dso->loadmap) {
 573                 size_t i;
 574                 for (i=0; i<dso->loadmap->nsegs; i++) {
 575                         if (!dso->loadmap->segs[i].p_memsz)
 576                                 continue;
 577                         munmap((void *)dso->loadmap->segs[i].addr,
 578                                 dso->loadmap->segs[i].p_memsz);
 579                 }
 580                 free(dso->loadmap);
 581         } else if (dso->map && dso->map_len) {
 582                 munmap(dso->map, dso->map_len);
 583         }
 584 }
 585
 586 static void *map_library(int fd, struct dso *dso)
 587 {
 588         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 589         void *allocated_buf=0;
 590         size_t phsize;
 591         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 592         size_t this_min, this_max;
 593         size_t nsegs = 0;
 594         off_t off_start;
 595         Ehdr *eh;
 596         Phdr *ph, *ph0;
 597         unsigned prot;
 598         unsigned char *map=MAP_FAILED, *base;
 599         size_t dyn=0;
 600         size_t tls_image=0;
 601         size_t i;
 602
 603         ssize_t l = read(fd, buf, sizeof buf);
 604         eh = buf;
 605         if (l<0) return 0;
 606         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 607                 goto noexec;
 608         phsize = eh->e_phentsize * eh->e_phnum;
 609         if (phsize > sizeof buf - sizeof *eh) {
 610                 allocated_buf = malloc(phsize);
 611                 if (!allocated_buf) return 0;
 612                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 613                 if (l < 0) goto error;
 614                 if (l != phsize) goto noexec;
 615                 ph = ph0 = allocated_buf;
 616         } else if (eh->e_phoff + phsize > l) {
 617                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 618                 if (l < 0) goto error;
 619                 if (l != phsize) goto noexec;
 620                 ph = ph0 = (void *)(buf + 1);
 621         } else {
 622                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 623         }
 624         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 625                 if (ph->p_type == PT_DYNAMIC) {
 626                         dyn = ph->p_vaddr;
 627                 } else if (ph->p_type == PT_TLS) {
 628                         tls_image = ph->p_vaddr;
 629                         dso->tls.align = ph->p_align;
 630                         dso->tls.len = ph->p_filesz;
 631                         dso->tls.size = ph->p_memsz;
 632                 } else if (ph->p_type == PT_GNU_RELRO) {
 633                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 634                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 635                 } else if (ph->p_type == PT_GNU_STACK) {
 636                         if (!runtime && ph->p_memsz > __default_stacksize) {
 637                                 __default_stacksize =
 638                                         ph->p_memsz < DEFAULT_STACK_MAX ?
 639                                         ph->p_memsz : DEFAULT_STACK_MAX;
 640                         }
 641                 }
 642                 if (ph->p_type != PT_LOAD) continue;
 643                 nsegs++;
 644                 if (ph->p_vaddr < addr_min) {
 645                         addr_min = ph->p_vaddr;
 646                         off_start = ph->p_offset;
 647                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 648                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 649                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 650                 }
 651                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 652                         addr_max = ph->p_vaddr+ph->p_memsz;
 653                 }
 654         }
 655         if (!dyn) goto noexec;
 656         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 657                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 658                         + nsegs * sizeof *dso->loadmap->segs);
 659                 if (!dso->loadmap) goto error;
 660                 dso->loadmap->nsegs = nsegs;
 661                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 662                         if (ph->p_type != PT_LOAD) continue;
 663                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 664                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 665                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 666                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 667                                 prot, MAP_PRIVATE,
 668                                 fd, ph->p_offset & -PAGE_SIZE);
 669                         if (map == MAP_FAILED) {
 670                                 unmap_library(dso);
 671                                 goto error;
 672                         }
 673                         dso->loadmap->segs[i].addr = (size_t)map +
 674                                 (ph->p_vaddr & PAGE_SIZE-1);
 675                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 676                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 677                         i++;
 678                         if (prot & PROT_WRITE) {
 679                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 680                                         + ph->p_filesz;
 681                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 682                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 683                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 684                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 685                                         pgend-pgbrk, prot,
 686                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 687                                         -1, off_start) == MAP_FAILED)
 688                                         goto error;
 689                                 memset(map + brk, 0, pgbrk-brk);
 690                         }
 691                 }
 692                 map = (void *)dso->loadmap->segs[0].addr;
 693                 map_len = 0;
 694                 goto done_mapping;
 695         }
 696         addr_max += PAGE_SIZE-1;
 697         addr_max &= -PAGE_SIZE;
 698         addr_min &= -PAGE_SIZE;
 699         off_start &= -PAGE_SIZE;
 700         map_len = addr_max - addr_min + off_start;
 701         /* The first time, we map too much, possibly even more than
 702          * the length of the file. This is okay because we will not
 703          * use the invalid part; we just need to reserve the right
 704          * amount of virtual address space to map over later. */
 705         map = DL_NOMMU_SUPPORT
 706                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 707                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 708                 : mmap((void *)addr_min, map_len, prot,
 709                         MAP_PRIVATE, fd, off_start);
 710         if (map==MAP_FAILED) goto error;
 711         dso->map = map;
 712         dso->map_len = map_len;
 713         /* If the loaded file is not relocatable and the requested address is
 714          * not available, then the load operation must fail. */
 715         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 716                 errno = EBUSY;
 717                 goto error;
 718         }
 719         base = map - addr_min;
 720         dso->phdr = 0;
 721         dso->phnum = 0;
 722         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 723                 if (ph->p_type != PT_LOAD) continue;
 724                 /* Check if the programs headers are in this load segment, and
 725                  * if so, record the address for use by dl_iterate_phdr. */
 726                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 727                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 728                         dso->phdr = (void *)(base + ph->p_vaddr
 729                                 + (eh->e_phoff-ph->p_offset));
 730                         dso->phnum = eh->e_phnum;
 731                         dso->phentsize = eh->e_phentsize;
 732                 }
 733                 this_min = ph->p_vaddr & -PAGE_SIZE;
 734                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 735                 off_start = ph->p_offset & -PAGE_SIZE;
 736                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 737                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 738                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 739                 /* Reuse the existing mapping for the lowest-address LOAD */
 740                 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
 741                         if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 742                                 goto error;
 743                 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
 744                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 745                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 746                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 747                         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)
 748                                 goto error;
 749                 }
 750         }
 751         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 752                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 753                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 754                             && errno != ENOSYS)
 755                                 goto error;
 756                         break;
 757                 }
 758 done_mapping:
 759         dso->base = base;
 760         dso->dynv = laddr(dso, dyn);
 761         if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
 762         free(allocated_buf);
 763         return map;
 764 noexec:
 765         errno = ENOEXEC;
 766 error:
 767         if (map!=MAP_FAILED) unmap_library(dso);
 768         free(allocated_buf);
 769         return 0;
 770 }
 771
 772 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 773 {
 774         size_t l;
 775         int fd;
 776         for (;;) {
 777                 s += strspn(s, ":\n");
 778                 l = strcspn(s, ":\n");
 779                 if (l-1 >= INT_MAX) return -1;
 780                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 781                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 782                         switch (errno) {
 783                         case ENOENT:
 784                         case ENOTDIR:
 785                         case EACCES:
 786                         case ENAMETOOLONG:
 787                                 break;
 788                         default:
 789                                 /* Any negative value but -1 will inhibit
 790                                  * futher path search. */
 791                                 return -2;
 792                         }
 793                 }
 794                 s += l;
 795         }
 796 }
 797
 798 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 799 {
 800         size_t n, l;
 801         const char *s, *t, *origin;
 802         char *d;
 803         if (p->rpath || !p->rpath_orig) return 0;
 804         if (!strchr(p->rpath_orig, '$')) {
 805                 p->rpath = p->rpath_orig;
 806                 return 0;
 807         }
 808         n = 0;
 809         s = p->rpath_orig;
 810         while ((t=strchr(s, '$'))) {
 811                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 812                         return 0;
 813                 s = t+1;
 814                 n++;
 815         }
 816         if (n > SSIZE_MAX/PATH_MAX) return 0;
 817
 818         if (p->kernel_mapped) {
 819                 /* $ORIGIN searches cannot be performed for the main program
 820                  * when it is suid/sgid/AT_SECURE. This is because the
 821                  * pathname is under the control of the caller of execve.
 822                  * For libraries, however, $ORIGIN can be processed safely
 823                  * since the library's pathname came from a trusted source
 824                  * (either system paths or a call to dlopen). */
 825                 if (libc.secure)
 826                         return 0;
 827                 l = readlink("/proc/self/exe", buf, buf_size);
 828                 if (l == -1) switch (errno) {
 829                 case ENOENT:
 830                 case ENOTDIR:
 831                 case EACCES:
 832                         break;
 833                 default:
 834                         return -1;
 835                 }
 836                 if (l >= buf_size)
 837                         return 0;
 838                 buf[l] = 0;
 839                 origin = buf;
 840         } else {
 841                 origin = p->name;
 842         }
 843         t = strrchr(origin, '/');
 844         if (t) {
 845                 l = t-origin;
 846         } else {
 847                 /* Normally p->name will always be an absolute or relative
 848                  * pathname containing at least one '/' character, but in the
 849                  * case where ldso was invoked as a command to execute a
 850                  * program in the working directory, app.name may not. Fix. */
 851                 origin = ".";
 852                 l = 1;
 853         }
 854         /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
 855         if (libc.secure && *origin != '/')
 856                 return 0;
 857         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 858         if (!p->rpath) return -1;
 859
 860         d = p->rpath;
 861         s = p->rpath_orig;
 862         while ((t=strchr(s, '$'))) {
 863                 memcpy(d, s, t-s);
 864                 d += t-s;
 865                 memcpy(d, origin, l);
 866                 d += l;
 867                 /* It was determined previously that the '$' is followed
 868                  * either by "ORIGIN" or "{ORIGIN}". */
 869                 s = t + 7 + 2*(t[1]=='{');
 870         }
 871         strcpy(d, s);
 872         return 0;
 873 }
 874
 875 static void decode_dyn(struct dso *p)
 876 {
 877         size_t dyn[DYN_CNT];
 878         decode_vec(p->dynv, dyn, DYN_CNT);
 879         p->syms = laddr(p, dyn[DT_SYMTAB]);
 880         p->strings = laddr(p, dyn[DT_STRTAB]);
 881         if (dyn[0]&(1<<DT_HASH))
 882                 p->hashtab = laddr(p, dyn[DT_HASH]);
 883         if (dyn[0]&(1<<DT_RPATH))
 884                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 885         if (dyn[0]&(1<<DT_RUNPATH))
 886                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 887         if (dyn[0]&(1<<DT_PLTGOT))
 888                 p->got = laddr(p, dyn[DT_PLTGOT]);
 889         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 890                 p->ghashtab = laddr(p, *dyn);
 891         if (search_vec(p->dynv, dyn, DT_VERSYM))
 892                 p->versym = laddr(p, *dyn);
 893 }
 894
 895 static size_t count_syms(struct dso *p)
 896 {
 897         if (p->hashtab) return p->hashtab[1];
 898
 899         size_t nsym, i;
 900         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 901         uint32_t *hashval;
 902         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 903                 if (buckets[i] > nsym)
 904                         nsym = buckets[i];
 905         }
 906         if (nsym) {
 907                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 908                 do nsym++;
 909                 while (!(*hashval++ & 1));
 910         }
 911         return nsym;
 912 }
 913
 914 static void *dl_mmap(size_t n)
 915 {
 916         void *p;
 917         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 918 #ifdef SYS_mmap2
 919         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 920 #else
 921         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 922 #endif
 923         return (unsigned long)p > -4096UL ? 0 : p;
 924 }
 925
 926 static void makefuncdescs(struct dso *p)
 927 {
 928         static int self_done;
 929         size_t nsym = count_syms(p);
 930         size_t i, size = nsym * sizeof(*p->funcdescs);
 931
 932         if (!self_done) {
 933                 p->funcdescs = dl_mmap(size);
 934                 self_done = 1;
 935         } else {
 936                 p->funcdescs = malloc(size);
 937         }
 938         if (!p->funcdescs) {
 939                 if (!runtime) a_crash();
 940                 error("Error allocating function descriptors for %s", p->name);
 941                 longjmp(*rtld_fail, 1);
 942         }
 943         for (i=0; i<nsym; i++) {
 944                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 945                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 946                         p->funcdescs[i].got = p->got;
 947                 } else {
 948                         p->funcdescs[i].addr = 0;
 949                         p->funcdescs[i].got = 0;
 950                 }
 951         }
 952 }
 953
 954 static struct dso *load_library(const char *name, struct dso *needed_by)
 955 {
 956         char buf[2*NAME_MAX+2];
 957         const char *pathname;
 958         unsigned char *map;
 959         struct dso *p, temp_dso = {0};
 960         int fd;
 961         struct stat st;
 962         size_t alloc_size;
 963         int n_th = 0;
 964         int is_self = 0;
 965
 966         if (!*name) {
 967                 errno = EINVAL;
 968                 return 0;
 969         }
 970
 971         /* Catch and block attempts to reload the implementation itself */
 972         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 973                 static const char reserved[] =
 974                         "c.pthread.rt.m.dl.util.xnet.";
 975                 const char *rp, *next;
 976                 for (rp=reserved; *rp; rp=next) {
 977                         next = strchr(rp, '.') + 1;
 978                         if (strncmp(name+3, rp, next-rp) == 0)
 979                                 break;
 980                 }
 981                 if (*rp) {
 982                         if (ldd_mode) {
 983                                 /* Track which names have been resolved
 984                                  * and only report each one once. */
 985                                 static unsigned reported;
 986                                 unsigned mask = 1U<<(rp-reserved);
 987                                 if (!(reported & mask)) {
 988                                         reported |= mask;
 989                                         dprintf(1, "\t%s => %s (%p)\n",
 990                                                 name, ldso.name,
 991                                                 ldso.base);
 992                                 }
 993                         }
 994                         is_self = 1;
 995                 }
 996         }
 997         if (!strcmp(name, ldso.name)) is_self = 1;
 998         if (is_self) {
 999                 if (!ldso.prev) {
1000                         tail->next = &ldso;
1001                         ldso.prev = tail;
1002                         tail = &ldso;
1003                 }
1004                 return &ldso;
1005         }
1006         if (strchr(name, '/')) {
1007                 pathname = name;
1008                 fd = open(name, O_RDONLY|O_CLOEXEC);
1009         } else {
1010                 /* Search for the name to see if it's already loaded */
1011                 for (p=head->next; p; p=p->next) {
1012                         if (p->shortname && !strcmp(p->shortname, name)) {
1013                                 return p;
1014                         }
1015                 }
1016                 if (strlen(name) > NAME_MAX) return 0;
1017                 fd = -1;
1018                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
1019                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
1020                         if (fixup_rpath(p, buf, sizeof buf) < 0)
1021                                 fd = -2; /* Inhibit further search. */
1022                         if (p->rpath)
1023                                 fd = path_open(name, p->rpath, buf, sizeof buf);
1024                 }
1025                 if (fd == -1) {
1026                         if (!sys_path) {
1027                                 char *prefix = 0;
1028                                 size_t prefix_len;
1029                                 if (ldso.name[0]=='/') {
1030                                         char *s, *t, *z;
1031                                         for (s=t=z=ldso.name; *s; s++)
1032                                                 if (*s=='/') z=t, t=s;
1033                                         prefix_len = z-ldso.name;
1034                                         if (prefix_len < PATH_MAX)
1035                                                 prefix = ldso.name;
1036                                 }
1037                                 if (!prefix) {
1038                                         prefix = "";
1039                                         prefix_len = 0;
1040                                 }
1041                                 char etc_ldso_path[prefix_len + 1
1042                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1043                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1044                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1045                                         (int)prefix_len, prefix);
1046                                 FILE *f = fopen(etc_ldso_path, "rbe");
1047                                 if (f) {
1048                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1049                                                 free(sys_path);
1050                                                 sys_path = "";
1051                                         }
1052                                         fclose(f);
1053                                 } else if (errno != ENOENT) {
1054                                         sys_path = "";
1055                                 }
1056                         }
1057                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1058                         fd = path_open(name, sys_path, buf, sizeof buf);
1059                 }
1060                 pathname = buf;
1061         }
1062         if (fd < 0) return 0;
1063         if (fstat(fd, &st) < 0) {
1064                 close(fd);
1065                 return 0;
1066         }
1067         for (p=head->next; p; p=p->next) {
1068                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1069                         /* If this library was previously loaded with a
1070                          * pathname but a search found the same inode,
1071                          * setup its shortname so it can be found by name. */
1072                         if (!p->shortname && pathname != name)
1073                                 p->shortname = strrchr(p->name, '/')+1;
1074                         close(fd);
1075                         return p;
1076                 }
1077         }
1078         map = noload ? 0 : map_library(fd, &temp_dso);
1079         close(fd);
1080         if (!map) return 0;
1081
1082         /* Avoid the danger of getting two versions of libc mapped into the
1083          * same process when an absolute pathname was used. The symbols
1084          * checked are chosen to catch both musl and glibc, and to avoid
1085          * false positives from interposition-hack libraries. */
1086         decode_dyn(&temp_dso);
1087         if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1088             find_sym(&temp_dso, "stdin", 1).sym) {
1089                 unmap_library(&temp_dso);
1090                 return load_library("libc.so", needed_by);
1091         }
1092         /* Past this point, if we haven't reached runtime yet, ldso has
1093          * committed either to use the mapped library or to abort execution.
1094          * Unmapping is not possible, so we can safely reclaim gaps. */
1095         if (!runtime) reclaim_gaps(&temp_dso);
1096
1097         /* Allocate storage for the new DSO. When there is TLS, this
1098          * storage must include a reservation for all pre-existing
1099          * threads to obtain copies of both the new TLS, and an
1100          * extended DTV capable of storing an additional slot for
1101          * the newly-loaded DSO. */
1102         alloc_size = sizeof *p + strlen(pathname) + 1;
1103         if (runtime && temp_dso.tls.image) {
1104                 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1105                         + sizeof(void *) * (tls_cnt+3);
1106                 n_th = libc.threads_minus_1 + 1;
1107                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1108                 else alloc_size += n_th * per_th;
1109         }
1110         p = calloc(1, alloc_size);
1111         if (!p) {
1112                 unmap_library(&temp_dso);
1113                 return 0;
1114         }
1115         memcpy(p, &temp_dso, sizeof temp_dso);
1116         p->dev = st.st_dev;
1117         p->ino = st.st_ino;
1118         p->needed_by = needed_by;
1119         p->name = p->buf;
1120         p->runtime_loaded = runtime;
1121         strcpy(p->name, pathname);
1122         /* Add a shortname only if name arg was not an explicit pathname. */
1123         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1124         if (p->tls.image) {
1125                 p->tls_id = ++tls_cnt;
1126                 tls_align = MAXP2(tls_align, p->tls.align);
1127 #ifdef TLS_ABOVE_TP
1128                 p->tls.offset = tls_offset + ( (p->tls.align-1) &
1129                         (-tls_offset + (uintptr_t)p->tls.image) );
1130                 tls_offset = p->tls.offset + p->tls.size;
1131 #else
1132                 tls_offset += p->tls.size + p->tls.align - 1;
1133                 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1134                         & (p->tls.align-1);
1135                 p->tls.offset = tls_offset;
1136 #endif
1137                 p->new_dtv = (void *)(-sizeof(size_t) &
1138                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1139                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1140                 if (tls_tail) tls_tail->next = &p->tls;
1141                 else libc.tls_head = &p->tls;
1142                 tls_tail = &p->tls;
1143         }
1144
1145         tail->next = p;
1146         p->prev = tail;
1147         tail = p;
1148
1149         if (DL_FDPIC) makefuncdescs(p);
1150
1151         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1152
1153         return p;
1154 }
1155
1156 static void load_direct_deps(struct dso *p)
1157 {
1158         size_t i, cnt=0;
1159
1160         if (p->deps) return;
1161         /* For head, all preloads are direct pseudo-dependencies.
1162          * Count and include them now to avoid realloc later. */
1163         if (p==head) for (struct dso *q=p->next; q; q=q->next)
1164                 cnt++;
1165         for (i=0; p->dynv[i]; i+=2)
1166                 if (p->dynv[i] == DT_NEEDED) cnt++;
1167         /* Use builtin buffer for apps with no external deps, to
1168          * preserve property of no runtime failure paths. */
1169         p->deps = (p==head && cnt<2) ? builtin_deps :
1170                 calloc(cnt+1, sizeof *p->deps);
1171         if (!p->deps) {
1172                 error("Error loading dependencies for %s", p->name);
1173                 if (runtime) longjmp(*rtld_fail, 1);
1174         }
1175         cnt=0;
1176         if (p==head) for (struct dso *q=p->next; q; q=q->next)
1177                 p->deps[cnt++] = q;
1178         for (i=0; p->dynv[i]; i+=2) {
1179                 if (p->dynv[i] != DT_NEEDED) continue;
1180                 struct dso *dep = load_library(p->strings + p->dynv[i+1], p);
1181                 if (!dep) {
1182                         error("Error loading shared library %s: %m (needed by %s)",
1183                                 p->strings + p->dynv[i+1], p->name);
1184                         if (runtime) longjmp(*rtld_fail, 1);
1185                         continue;
1186                 }
1187                 p->deps[cnt++] = dep;
1188         }
1189         p->deps[cnt] = 0;
1190         p->ndeps_direct = cnt;
1191 }
1192
1193 static void load_deps(struct dso *p)
1194 {
1195         if (p->deps) return;
1196         for (; p; p=p->next)
1197                 load_direct_deps(p);
1198 }
1199
1200 static void extend_bfs_deps(struct dso *p)
1201 {
1202         size_t i, j, cnt, ndeps_all;
1203         struct dso **tmp;
1204
1205         /* Can't use realloc if the original p->deps was allocated at
1206          * program entry and malloc has been replaced, or if it's
1207          * the builtin non-allocated trivial main program deps array. */
1208         int no_realloc = (__malloc_replaced && !p->runtime_loaded)
1209                 || p->deps == builtin_deps;
1210
1211         if (p->bfs_built) return;
1212         ndeps_all = p->ndeps_direct;
1213
1214         /* Mark existing (direct) deps so they won't be duplicated. */
1215         for (i=0; p->deps[i]; i++)
1216                 p->deps[i]->mark = 1;
1217
1218         /* For each dependency already in the list, copy its list of direct
1219          * dependencies to the list, excluding any items already in the
1220          * list. Note that the list this loop iterates over will grow during
1221          * the loop, but since duplicates are excluded, growth is bounded. */
1222         for (i=0; p->deps[i]; i++) {
1223                 struct dso *dep = p->deps[i];
1224                 for (j=cnt=0; j<dep->ndeps_direct; j++)
1225                         if (!dep->deps[j]->mark) cnt++;
1226                 tmp = no_realloc ?
1227                         malloc(sizeof(*tmp) * (ndeps_all+cnt+1)) :
1228                         realloc(p->deps, sizeof(*tmp) * (ndeps_all+cnt+1));
1229                 if (!tmp) {
1230                         error("Error recording dependencies for %s", p->name);
1231                         if (runtime) longjmp(*rtld_fail, 1);
1232                         continue;
1233                 }
1234                 if (no_realloc) {
1235                         memcpy(tmp, p->deps, sizeof(*tmp) * (ndeps_all+1));
1236                         no_realloc = 0;
1237                 }
1238                 p->deps = tmp;
1239                 for (j=0; j<dep->ndeps_direct; j++) {
1240                         if (dep->deps[j]->mark) continue;
1241                         dep->deps[j]->mark = 1;
1242                         p->deps[ndeps_all++] = dep->deps[j];
1243                 }
1244                 p->deps[ndeps_all] = 0;
1245         }
1246         p->bfs_built = 1;
1247         for (p=head; p; p=p->next)
1248                 p->mark = 0;
1249 }
1250
1251 static void load_preload(char *s)
1252 {
1253         int tmp;
1254         char *z;
1255         for (z=s; *z; s=z) {
1256                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1257                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1258                 tmp = *z;
1259                 *z = 0;
1260                 load_library(s, 0);
1261                 *z = tmp;
1262         }
1263 }
1264
1265 static void add_syms(struct dso *p)
1266 {
1267         if (!p->syms_next && syms_tail != p) {
1268                 syms_tail->syms_next = p;
1269                 syms_tail = p;
1270         }
1271 }
1272
1273 static void revert_syms(struct dso *old_tail)
1274 {
1275         struct dso *p, *next;
1276         /* Chop off the tail of the list of dsos that participate in
1277          * the global symbol table, reverting them to RTLD_LOCAL. */
1278         for (p=old_tail; p; p=next) {
1279                 next = p->syms_next;
1280                 p->syms_next = 0;
1281         }
1282         syms_tail = old_tail;
1283 }
1284
1285 static void do_mips_relocs(struct dso *p, size_t *got)
1286 {
1287         size_t i, j, rel[2];
1288         unsigned char *base = p->base;
1289         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1290         if (p==&ldso) {
1291                 got += i;
1292         } else {
1293                 while (i--) *got++ += (size_t)base;
1294         }
1295         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1296         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1297         Sym *sym = p->syms + j;
1298         rel[0] = (unsigned char *)got - base;
1299         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1300                 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1301                 do_relocs(p, rel, sizeof rel, 2);
1302         }
1303 }
1304
1305 static void reloc_all(struct dso *p)
1306 {
1307         size_t dyn[DYN_CNT];
1308         for (; p; p=p->next) {
1309                 if (p->relocated) continue;
1310                 decode_vec(p->dynv, dyn, DYN_CNT);
1311                 if (NEED_MIPS_GOT_RELOCS)
1312                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1313                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1314                         2+(dyn[DT_PLTREL]==DT_RELA));
1315                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1316                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1317
1318                 if (head != &ldso && p->relro_start != p->relro_end &&
1319                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1320                     && errno != ENOSYS) {
1321                         error("Error relocating %s: RELRO protection failed: %m",
1322                                 p->name);
1323                         if (runtime) longjmp(*rtld_fail, 1);
1324                 }
1325
1326                 p->relocated = 1;
1327         }
1328 }
1329
1330 static void kernel_mapped_dso(struct dso *p)
1331 {
1332         size_t min_addr = -1, max_addr = 0, cnt;
1333         Phdr *ph = p->phdr;
1334         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1335                 if (ph->p_type == PT_DYNAMIC) {
1336                         p->dynv = laddr(p, ph->p_vaddr);
1337                 } else if (ph->p_type == PT_GNU_RELRO) {
1338                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1339                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1340                 } else if (ph->p_type == PT_GNU_STACK) {
1341                         if (!runtime && ph->p_memsz > __default_stacksize) {
1342                                 __default_stacksize =
1343                                         ph->p_memsz < DEFAULT_STACK_MAX ?
1344                                         ph->p_memsz : DEFAULT_STACK_MAX;
1345                         }
1346                 }
1347                 if (ph->p_type != PT_LOAD) continue;
1348                 if (ph->p_vaddr < min_addr)
1349                         min_addr = ph->p_vaddr;
1350                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1351                         max_addr = ph->p_vaddr+ph->p_memsz;
1352         }
1353         min_addr &= -PAGE_SIZE;
1354         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1355         p->map = p->base + min_addr;
1356         p->map_len = max_addr - min_addr;
1357         p->kernel_mapped = 1;
1358 }
1359
1360 void __libc_exit_fini()
1361 {
1362         struct dso *p;
1363         size_t dyn[DYN_CNT];
1364         int self = __pthread_self()->tid;
1365
1366         /* Take both locks before setting shutting_down, so that
1367          * either lock is sufficient to read its value. The lock
1368          * order matches that in dlopen to avoid deadlock. */
1369         pthread_rwlock_wrlock(&lock);
1370         pthread_mutex_lock(&init_fini_lock);
1371         shutting_down = 1;
1372         pthread_rwlock_unlock(&lock);
1373         for (p=fini_head; p; p=p->fini_next) {
1374                 while (p->ctor_visitor && p->ctor_visitor!=self)
1375                         pthread_cond_wait(&ctor_cond, &init_fini_lock);
1376                 if (!p->constructed) continue;
1377                 decode_vec(p->dynv, dyn, DYN_CNT);
1378                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1379                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1380                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1381                         while (n--) ((void (*)(void))*--fn)();
1382                 }
1383 #ifndef NO_LEGACY_INITFINI
1384                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1385                         fpaddr(p, dyn[DT_FINI])();
1386 #endif
1387         }
1388 }
1389
1390 static struct dso **queue_ctors(struct dso *dso)
1391 {
1392         size_t cnt, qpos, spos, i;
1393         struct dso *p, **queue, **stack;
1394
1395         if (ldd_mode) return 0;
1396
1397         /* Bound on queue size is the total number of indirect deps.
1398          * If a bfs deps list was built, we can use it. Otherwise,
1399          * bound by the total number of DSOs, which is always safe and
1400          * is reasonable we use it (for main app at startup). */
1401         if (dso->bfs_built) {
1402                 for (cnt=0; dso->deps[cnt]; cnt++)
1403                         dso->deps[cnt]->mark = 0;
1404                 cnt++; /* self, not included in deps */
1405         } else {
1406                 for (cnt=0, p=head; p; cnt++, p=p->next)
1407                         p->mark = 0;
1408         }
1409         cnt++; /* termination slot */
1410         if (dso==head && cnt <= countof(builtin_ctor_queue))
1411                 queue = builtin_ctor_queue;
1412         else
1413                 queue = calloc(cnt, sizeof *queue);
1414
1415         if (!queue) {
1416                 error("Error allocating constructor queue: %m\n");
1417                 if (runtime) longjmp(*rtld_fail, 1);
1418                 return 0;
1419         }
1420
1421         /* Opposite ends of the allocated buffer serve as an output queue
1422          * and a working stack. Setup initial stack with just the argument
1423          * dso and initial queue empty... */
1424         stack = queue;
1425         qpos = 0;
1426         spos = cnt;
1427         stack[--spos] = dso;
1428         dso->next_dep = 0;
1429         dso->mark = 1;
1430
1431         /* Then perform pseudo-DFS sort, but ignoring circular deps. */
1432         while (spos<cnt) {
1433                 p = stack[spos++];
1434                 while (p->next_dep < p->ndeps_direct) {
1435                         if (p->deps[p->next_dep]->mark) {
1436                                 p->next_dep++;
1437                         } else {
1438                                 stack[--spos] = p;
1439                                 p = p->deps[p->next_dep];
1440                                 p->next_dep = 0;
1441                                 p->mark = 1;
1442                         }
1443                 }
1444                 queue[qpos++] = p;
1445         }
1446         queue[qpos] = 0;
1447         for (i=0; i<qpos; i++) queue[i]->mark = 0;
1448
1449         return queue;
1450 }
1451
1452 static void do_init_fini(struct dso **queue)
1453 {
1454         struct dso *p;
1455         size_t dyn[DYN_CNT], i;
1456         int self = __pthread_self()->tid;
1457
1458         pthread_mutex_lock(&init_fini_lock);
1459         for (i=0; (p=queue[i]); i++) {
1460                 while ((p->ctor_visitor && p->ctor_visitor!=self) || shutting_down)
1461                         pthread_cond_wait(&ctor_cond, &init_fini_lock);
1462                 if (p->ctor_visitor || p->constructed)
1463                         continue;
1464                 p->ctor_visitor = self;
1465
1466                 decode_vec(p->dynv, dyn, DYN_CNT);
1467                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1468                         p->fini_next = fini_head;
1469                         fini_head = p;
1470                 }
1471
1472                 pthread_mutex_unlock(&init_fini_lock);
1473
1474 #ifndef NO_LEGACY_INITFINI
1475                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1476                         fpaddr(p, dyn[DT_INIT])();
1477 #endif
1478                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1479                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1480                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1481                         while (n--) ((void (*)(void))*fn++)();
1482                 }
1483
1484                 pthread_mutex_lock(&init_fini_lock);
1485                 p->ctor_visitor = 0;
1486                 p->constructed = 1;
1487                 pthread_cond_broadcast(&ctor_cond);
1488         }
1489         pthread_mutex_unlock(&init_fini_lock);
1490 }
1491
1492 void __libc_start_init(void)
1493 {
1494         do_init_fini(main_ctor_queue);
1495         if (!__malloc_replaced && main_ctor_queue != builtin_ctor_queue)
1496                 free(main_ctor_queue);
1497         main_ctor_queue = 0;
1498 }
1499
1500 static void dl_debug_state(void)
1501 {
1502 }
1503
1504 weak_alias(dl_debug_state, _dl_debug_state);
1505
1506 void __init_tls(size_t *auxv)
1507 {
1508 }
1509
1510 static void update_tls_size()
1511 {
1512         libc.tls_cnt = tls_cnt;
1513         libc.tls_align = tls_align;
1514         libc.tls_size = ALIGN(
1515                 (1+tls_cnt) * sizeof(void *) +
1516                 tls_offset +
1517                 sizeof(struct pthread) +
1518                 tls_align * 2,
1519         tls_align);
1520 }
1521
1522 static void install_new_tls(void)
1523 {
1524         sigset_t set;
1525         pthread_t self = __pthread_self(), td;
1526         struct dso *dtv_provider = container_of(tls_tail, struct dso, tls);
1527         uintptr_t (*newdtv)[tls_cnt+1] = (void *)dtv_provider->new_dtv;
1528         struct dso *p;
1529         size_t i, j;
1530         size_t old_cnt = self->dtv[0];
1531
1532         __block_app_sigs(&set);
1533         __tl_lock();
1534         /* Copy existing dtv contents from all existing threads. */
1535         for (i=0, td=self; !i || td!=self; i++, td=td->next) {
1536                 memcpy(newdtv+i, td->dtv,
1537                         (old_cnt+1)*sizeof(uintptr_t));
1538                 newdtv[i][0] = tls_cnt;
1539         }
1540         /* Install new dtls into the enlarged, uninstalled dtv copies. */
1541         for (p=head; ; p=p->next) {
1542                 if (p->tls_id <= old_cnt) continue;
1543                 unsigned char *mem = p->new_tls;
1544                 for (j=0; j<i; j++) {
1545                         unsigned char *new = mem;
1546                         new += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1547                                 & (p->tls.align-1);
1548                         memcpy(new, p->tls.image, p->tls.len);
1549                         newdtv[j][p->tls_id] =
1550                                 (uintptr_t)new + DTP_OFFSET;
1551                         mem += p->tls.size + p->tls.align;
1552                 }
1553                 if (p->tls_id == tls_cnt) break;
1554         }
1555
1556         /* Broadcast barrier to ensure contents of new dtv is visible
1557          * if the new dtv pointer is. The __membarrier function has a
1558          * fallback emulation using signals for kernels that lack the
1559          * feature at the syscall level. */
1560
1561         __membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED, 0);
1562
1563         /* Install new dtv for each thread. */
1564         for (j=0, td=self; !j || td!=self; j++, td=td->next) {
1565                 td->dtv = td->dtv_copy = newdtv[j];
1566         }
1567
1568         __tl_unlock();
1569         __restore_sigs(&set);
1570 }
1571
1572 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1573  * following stage 2 and stage 3 functions via primitive symbolic lookup
1574  * since it does not have access to their addresses to begin with. */
1575
1576 /* Stage 2 of the dynamic linker is called after relative relocations
1577  * have been processed. It can make function calls to static functions
1578  * and access string literals and static data, but cannot use extern
1579  * symbols. Its job is to perform symbolic relocations on the dynamic
1580  * linker itself, but some of the relocations performed may need to be
1581  * replaced later due to copy relocations in the main program. */
1582
1583 hidden void __dls2(unsigned char *base, size_t *sp)
1584 {
1585         if (DL_FDPIC) {
1586                 void *p1 = (void *)sp[-2];
1587                 void *p2 = (void *)sp[-1];
1588                 if (!p1) {
1589                         size_t *auxv, aux[AUX_CNT];
1590                         for (auxv=sp+1+*sp+1; *auxv; auxv++);
1591                         auxv++;
1592                         decode_vec(auxv, aux, AUX_CNT);
1593                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1594                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1595                 }
1596                 app_loadmap = p2 ? p1 : 0;
1597                 ldso.loadmap = p2 ? p2 : p1;
1598                 ldso.base = laddr(&ldso, 0);
1599         } else {
1600                 ldso.base = base;
1601         }
1602         Ehdr *ehdr = (void *)ldso.base;
1603         ldso.name = ldso.shortname = "libc.so";
1604         ldso.phnum = ehdr->e_phnum;
1605         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1606         ldso.phentsize = ehdr->e_phentsize;
1607         kernel_mapped_dso(&ldso);
1608         decode_dyn(&ldso);
1609
1610         if (DL_FDPIC) makefuncdescs(&ldso);
1611
1612         /* Prepare storage for to save clobbered REL addends so they
1613          * can be reused in stage 3. There should be very few. If
1614          * something goes wrong and there are a huge number, abort
1615          * instead of risking stack overflow. */
1616         size_t dyn[DYN_CNT];
1617         decode_vec(ldso.dynv, dyn, DYN_CNT);
1618         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1619         size_t rel_size = dyn[DT_RELSZ];
1620         size_t symbolic_rel_cnt = 0;
1621         apply_addends_to = rel;
1622         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1623                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1624         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1625         size_t addends[symbolic_rel_cnt+1];
1626         saved_addends = addends;
1627
1628         head = &ldso;
1629         reloc_all(&ldso);
1630
1631         ldso.relocated = 0;
1632
1633         /* Call dynamic linker stage-2b, __dls2b, looking it up
1634          * symbolically as a barrier against moving the address
1635          * load across the above relocation processing. */
1636         struct symdef dls2b_def = find_sym(&ldso, "__dls2b", 0);
1637         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls2b_def.sym-ldso.syms])(sp);
1638         else ((stage3_func)laddr(&ldso, dls2b_def.sym->st_value))(sp);
1639 }
1640
1641 /* Stage 2b sets up a valid thread pointer, which requires relocations
1642  * completed in stage 2, and on which stage 3 is permitted to depend.
1643  * This is done as a separate stage, with symbolic lookup as a barrier,
1644  * so that loads of the thread pointer and &errno can be pure/const and
1645  * thereby hoistable. */
1646
1647 void __dls2b(size_t *sp)
1648 {
1649         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1650          * use during dynamic linking. If possible it will also serve as the
1651          * thread pointer at runtime. */
1652         libc.tls_size = sizeof builtin_tls;
1653         libc.tls_align = tls_align;
1654         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1655                 a_crash();
1656         }
1657
1658         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1659         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1660         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1661 }
1662
1663 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1664  * fully functional. Its job is to load (if not already loaded) and
1665  * process dependencies and relocations for the main application and
1666  * transfer control to its entry point. */
1667
1668 void __dls3(size_t *sp)
1669 {
1670         static struct dso app, vdso;
1671         size_t aux[AUX_CNT], *auxv;
1672         size_t i;
1673         char *env_preload=0;
1674         char *replace_argv0=0;
1675         size_t vdso_base;
1676         int argc = *sp;
1677         char **argv = (void *)(sp+1);
1678         char **argv_orig = argv;
1679         char **envp = argv+argc+1;
1680
1681         /* Find aux vector just past environ[] and use it to initialize
1682          * global data that may be needed before we can make syscalls. */
1683         __environ = envp;
1684         for (i=argc+1; argv[i]; i++);
1685         libc.auxv = auxv = (void *)(argv+i+1);
1686         decode_vec(auxv, aux, AUX_CNT);
1687         __hwcap = aux[AT_HWCAP];
1688         search_vec(auxv, &__sysinfo, AT_SYSINFO);
1689         __pthread_self()->sysinfo = __sysinfo;
1690         libc.page_size = aux[AT_PAGESZ];
1691         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1692                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1693
1694         /* Only trust user/env if kernel says we're not suid/sgid */
1695         if (!libc.secure) {
1696                 env_path = getenv("LD_LIBRARY_PATH");
1697                 env_preload = getenv("LD_PRELOAD");
1698         }
1699
1700         /* If the main program was already loaded by the kernel,
1701          * AT_PHDR will point to some location other than the dynamic
1702          * linker's program headers. */
1703         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1704                 size_t interp_off = 0;
1705                 size_t tls_image = 0;
1706                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1707                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1708                 app.phnum = aux[AT_PHNUM];
1709                 app.phentsize = aux[AT_PHENT];
1710                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1711                         if (phdr->p_type == PT_PHDR)
1712                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1713                         else if (phdr->p_type == PT_INTERP)
1714                                 interp_off = (size_t)phdr->p_vaddr;
1715                         else if (phdr->p_type == PT_TLS) {
1716                                 tls_image = phdr->p_vaddr;
1717                                 app.tls.len = phdr->p_filesz;
1718                                 app.tls.size = phdr->p_memsz;
1719                                 app.tls.align = phdr->p_align;
1720                         }
1721                 }
1722                 if (DL_FDPIC) app.loadmap = app_loadmap;
1723                 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1724                 if (interp_off) ldso.name = laddr(&app, interp_off);
1725                 if ((aux[0] & (1UL<<AT_EXECFN))
1726                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1727                         app.name = (char *)aux[AT_EXECFN];
1728                 else
1729                         app.name = argv[0];
1730                 kernel_mapped_dso(&app);
1731         } else {
1732                 int fd;
1733                 char *ldname = argv[0];
1734                 size_t l = strlen(ldname);
1735                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1736                 argv++;
1737                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1738                         char *opt = argv[0]+2;
1739                         *argv++ = (void *)-1;
1740                         if (!*opt) {
1741                                 break;
1742                         } else if (!memcmp(opt, "list", 5)) {
1743                                 ldd_mode = 1;
1744                         } else if (!memcmp(opt, "library-path", 12)) {
1745                                 if (opt[12]=='=') env_path = opt+13;
1746                                 else if (opt[12]) *argv = 0;
1747                                 else if (*argv) env_path = *argv++;
1748                         } else if (!memcmp(opt, "preload", 7)) {
1749                                 if (opt[7]=='=') env_preload = opt+8;
1750                                 else if (opt[7]) *argv = 0;
1751                                 else if (*argv) env_preload = *argv++;
1752                         } else if (!memcmp(opt, "argv0", 5)) {
1753                                 if (opt[5]=='=') replace_argv0 = opt+6;
1754                                 else if (opt[5]) *argv = 0;
1755                                 else if (*argv) replace_argv0 = *argv++;
1756                         } else {
1757                                 argv[0] = 0;
1758                         }
1759                 }
1760                 argv[-1] = (void *)(argc - (argv-argv_orig));
1761                 if (!argv[0]) {
1762                         dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1763                                 "Version %s\n"
1764                                 "Dynamic Program Loader\n"
1765                                 "Usage: %s [options] [--] pathname%s\n",
1766                                 __libc_version, ldname,
1767                                 ldd_mode ? "" : " [args]");
1768                         _exit(1);
1769                 }
1770                 fd = open(argv[0], O_RDONLY);
1771                 if (fd < 0) {
1772                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1773                         _exit(1);
1774                 }
1775                 Ehdr *ehdr = (void *)map_library(fd, &app);
1776                 if (!ehdr) {
1777                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1778                         _exit(1);
1779                 }
1780                 close(fd);
1781                 ldso.name = ldname;
1782                 app.name = argv[0];
1783                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1784                 /* Find the name that would have been used for the dynamic
1785                  * linker had ldd not taken its place. */
1786                 if (ldd_mode) {
1787                         for (i=0; i<app.phnum; i++) {
1788                                 if (app.phdr[i].p_type == PT_INTERP)
1789                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1790                         }
1791                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1792                 }
1793         }
1794         if (app.tls.size) {
1795                 libc.tls_head = tls_tail = &app.tls;
1796                 app.tls_id = tls_cnt = 1;
1797 #ifdef TLS_ABOVE_TP
1798                 app.tls.offset = GAP_ABOVE_TP;
1799                 app.tls.offset += (-GAP_ABOVE_TP + (uintptr_t)app.tls.image)
1800                         & (app.tls.align-1);
1801                 tls_offset = app.tls.offset + app.tls.size;
1802 #else
1803                 tls_offset = app.tls.offset = app.tls.size
1804                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1805                         & (app.tls.align-1) );
1806 #endif
1807                 tls_align = MAXP2(tls_align, app.tls.align);
1808         }
1809         decode_dyn(&app);
1810         if (DL_FDPIC) {
1811                 makefuncdescs(&app);
1812                 if (!app.loadmap) {
1813                         app.loadmap = (void *)&app_dummy_loadmap;
1814                         app.loadmap->nsegs = 1;
1815                         app.loadmap->segs[0].addr = (size_t)app.map;
1816                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1817                                 - (size_t)app.base;
1818                         app.loadmap->segs[0].p_memsz = app.map_len;
1819                 }
1820                 argv[-3] = (void *)app.loadmap;
1821         }
1822
1823         /* Initial dso chain consists only of the app. */
1824         head = tail = syms_tail = &app;
1825
1826         /* Donate unused parts of app and library mapping to malloc */
1827         reclaim_gaps(&app);
1828         reclaim_gaps(&ldso);
1829
1830         /* Load preload/needed libraries, add symbols to global namespace. */
1831         ldso.deps = (struct dso **)no_deps;
1832         if (env_preload) load_preload(env_preload);
1833         load_deps(&app);
1834         for (struct dso *p=head; p; p=p->next)
1835                 add_syms(p);
1836
1837         /* Attach to vdso, if provided by the kernel, last so that it does
1838          * not become part of the global namespace.  */
1839         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1840                 Ehdr *ehdr = (void *)vdso_base;
1841                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1842                 vdso.phnum = ehdr->e_phnum;
1843                 vdso.phentsize = ehdr->e_phentsize;
1844                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1845                         if (phdr->p_type == PT_DYNAMIC)
1846                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1847                         if (phdr->p_type == PT_LOAD)
1848                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1849                 }
1850                 vdso.name = "";
1851                 vdso.shortname = "linux-gate.so.1";
1852                 vdso.relocated = 1;
1853                 vdso.deps = (struct dso **)no_deps;
1854                 decode_dyn(&vdso);
1855                 vdso.prev = tail;
1856                 tail->next = &vdso;
1857                 tail = &vdso;
1858         }
1859
1860         for (i=0; app.dynv[i]; i+=2) {
1861                 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1862                         app.dynv[i+1] = (size_t)&debug;
1863                 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1864                         size_t *ptr = (size_t *) app.dynv[i+1];
1865                         *ptr = (size_t)&debug;
1866                 }
1867         }
1868
1869         /* This must be done before final relocations, since it calls
1870          * malloc, which may be provided by the application. Calling any
1871          * application code prior to the jump to its entry point is not
1872          * valid in our model and does not work with FDPIC, where there
1873          * are additional relocation-like fixups that only the entry point
1874          * code can see to perform. */
1875         main_ctor_queue = queue_ctors(&app);
1876
1877         /* The main program must be relocated LAST since it may contin
1878          * copy relocations which depend on libraries' relocations. */
1879         reloc_all(app.next);
1880         reloc_all(&app);
1881
1882         update_tls_size();
1883         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1884                 void *initial_tls = calloc(libc.tls_size, 1);
1885                 if (!initial_tls) {
1886                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1887                                 argv[0], libc.tls_size);
1888                         _exit(127);
1889                 }
1890                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1891                         a_crash();
1892                 }
1893         } else {
1894                 size_t tmp_tls_size = libc.tls_size;
1895                 pthread_t self = __pthread_self();
1896                 /* Temporarily set the tls size to the full size of
1897                  * builtin_tls so that __copy_tls will use the same layout
1898                  * as it did for before. Then check, just to be safe. */
1899                 libc.tls_size = sizeof builtin_tls;
1900                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1901                 libc.tls_size = tmp_tls_size;
1902         }
1903         static_tls_cnt = tls_cnt;
1904
1905         if (ldso_fail) _exit(127);
1906         if (ldd_mode) _exit(0);
1907
1908         /* Determine if malloc was interposed by a replacement implementation
1909          * so that calloc and the memalign family can harden against the
1910          * possibility of incomplete replacement. */
1911         if (find_sym(head, "malloc", 1).dso != &ldso)
1912                 __malloc_replaced = 1;
1913
1914         /* Switch to runtime mode: any further failures in the dynamic
1915          * linker are a reportable failure rather than a fatal startup
1916          * error. */
1917         runtime = 1;
1918
1919         debug.ver = 1;
1920         debug.bp = dl_debug_state;
1921         debug.head = head;
1922         debug.base = ldso.base;
1923         debug.state = 0;
1924         _dl_debug_state();
1925
1926         if (replace_argv0) argv[0] = replace_argv0;
1927
1928         errno = 0;
1929
1930         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1931         for(;;);
1932 }
1933
1934 static void prepare_lazy(struct dso *p)
1935 {
1936         size_t dyn[DYN_CNT], n, flags1=0;
1937         decode_vec(p->dynv, dyn, DYN_CNT);
1938         search_vec(p->dynv, &flags1, DT_FLAGS_1);
1939         if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1940                 return;
1941         n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1942         if (NEED_MIPS_GOT_RELOCS) {
1943                 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1944                 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1945                 n += i-j;
1946         }
1947         p->lazy = calloc(n, 3*sizeof(size_t));
1948         if (!p->lazy) {
1949                 error("Error preparing lazy relocation for %s: %m", p->name);
1950                 longjmp(*rtld_fail, 1);
1951         }
1952         p->lazy_next = lazy_head;
1953         lazy_head = p;
1954 }
1955
1956 void *dlopen(const char *file, int mode)
1957 {
1958         struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1959         struct tls_module *orig_tls_tail;
1960         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1961         size_t i;
1962         int cs;
1963         jmp_buf jb;
1964         struct dso **volatile ctor_queue = 0;
1965
1966         if (!file) return head;
1967
1968         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1969         pthread_rwlock_wrlock(&lock);
1970         __inhibit_ptc();
1971
1972         p = 0;
1973         if (shutting_down) {
1974                 error("Cannot dlopen while program is exiting.");
1975                 goto end;
1976         }
1977         orig_tls_tail = tls_tail;
1978         orig_tls_cnt = tls_cnt;
1979         orig_tls_offset = tls_offset;
1980         orig_tls_align = tls_align;
1981         orig_lazy_head = lazy_head;
1982         orig_syms_tail = syms_tail;
1983         orig_tail = tail;
1984         noload = mode & RTLD_NOLOAD;
1985
1986         rtld_fail = &jb;
1987         if (setjmp(*rtld_fail)) {
1988                 /* Clean up anything new that was (partially) loaded */
1989                 revert_syms(orig_syms_tail);
1990                 for (p=orig_tail->next; p; p=next) {
1991                         next = p->next;
1992                         while (p->td_index) {
1993                                 void *tmp = p->td_index->next;
1994                                 free(p->td_index);
1995                                 p->td_index = tmp;
1996                         }
1997                         free(p->funcdescs);
1998                         if (p->rpath != p->rpath_orig)
1999                                 free(p->rpath);
2000                         free(p->deps);
2001                         unmap_library(p);
2002                         free(p);
2003                 }
2004                 free(ctor_queue);
2005                 ctor_queue = 0;
2006                 if (!orig_tls_tail) libc.tls_head = 0;
2007                 tls_tail = orig_tls_tail;
2008                 if (tls_tail) tls_tail->next = 0;
2009                 tls_cnt = orig_tls_cnt;
2010                 tls_offset = orig_tls_offset;
2011                 tls_align = orig_tls_align;
2012                 lazy_head = orig_lazy_head;
2013                 tail = orig_tail;
2014                 tail->next = 0;
2015                 p = 0;
2016                 goto end;
2017         } else p = load_library(file, head);
2018
2019         if (!p) {
2020                 error(noload ?
2021                         "Library %s is not already loaded" :
2022                         "Error loading shared library %s: %m",
2023                         file);
2024                 goto end;
2025         }
2026
2027         /* First load handling */
2028         load_deps(p);
2029         extend_bfs_deps(p);
2030         pthread_mutex_lock(&init_fini_lock);
2031         if (!p->constructed) ctor_queue = queue_ctors(p);
2032         pthread_mutex_unlock(&init_fini_lock);
2033         if (!p->relocated && (mode & RTLD_LAZY)) {
2034                 prepare_lazy(p);
2035                 for (i=0; p->deps[i]; i++)
2036                         if (!p->deps[i]->relocated)
2037                                 prepare_lazy(p->deps[i]);
2038         }
2039         if (!p->relocated || (mode & RTLD_GLOBAL)) {
2040                 /* Make new symbols global, at least temporarily, so we can do
2041                  * relocations. If not RTLD_GLOBAL, this is reverted below. */
2042                 add_syms(p);
2043                 for (i=0; p->deps[i]; i++)
2044                         add_syms(p->deps[i]);
2045         }
2046         if (!p->relocated) {
2047                 reloc_all(p);
2048         }
2049
2050         /* If RTLD_GLOBAL was not specified, undo any new additions
2051          * to the global symbol table. This is a nop if the library was
2052          * previously loaded and already global. */
2053         if (!(mode & RTLD_GLOBAL))
2054                 revert_syms(orig_syms_tail);
2055
2056         /* Processing of deferred lazy relocations must not happen until
2057          * the new libraries are committed; otherwise we could end up with
2058          * relocations resolved to symbol definitions that get removed. */
2059         redo_lazy_relocs();
2060
2061         update_tls_size();
2062         if (tls_cnt != orig_tls_cnt)
2063                 install_new_tls();
2064         _dl_debug_state();
2065         orig_tail = tail;
2066 end:
2067         __release_ptc();
2068         if (p) gencnt++;
2069         pthread_rwlock_unlock(&lock);
2070         if (ctor_queue) {
2071                 do_init_fini(ctor_queue);
2072                 free(ctor_queue);
2073         }
2074         pthread_setcancelstate(cs, 0);
2075         return p;
2076 }
2077
2078 hidden int __dl_invalid_handle(void *h)
2079 {
2080         struct dso *p;
2081         for (p=head; p; p=p->next) if (h==p) return 0;
2082         error("Invalid library handle %p", (void *)h);
2083         return 1;
2084 }
2085
2086 static void *addr2dso(size_t a)
2087 {
2088         struct dso *p;
2089         size_t i;
2090         if (DL_FDPIC) for (p=head; p; p=p->next) {
2091                 i = count_syms(p);
2092                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
2093                         return p;
2094         }
2095         for (p=head; p; p=p->next) {
2096                 if (DL_FDPIC && p->loadmap) {
2097                         for (i=0; i<p->loadmap->nsegs; i++) {
2098                                 if (a-p->loadmap->segs[i].p_vaddr
2099                                     < p->loadmap->segs[i].p_memsz)
2100                                         return p;
2101                         }
2102                 } else {
2103                         Phdr *ph = p->phdr;
2104                         size_t phcnt = p->phnum;
2105                         size_t entsz = p->phentsize;
2106                         size_t base = (size_t)p->base;
2107                         for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
2108                                 if (ph->p_type != PT_LOAD) continue;
2109                                 if (a-base-ph->p_vaddr < ph->p_memsz)
2110                                         return p;
2111                         }
2112                         if (a-(size_t)p->map < p->map_len)
2113                                 return 0;
2114                 }
2115         }
2116         return 0;
2117 }
2118
2119 static void *do_dlsym(struct dso *p, const char *s, void *ra)
2120 {
2121         size_t i;
2122         uint32_t h = 0, gh = 0, *ght;
2123         Sym *sym;
2124         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
2125                 if (p == RTLD_DEFAULT) {
2126                         p = head;
2127                 } else if (p == RTLD_NEXT) {
2128                         p = addr2dso((size_t)ra);
2129                         if (!p) p=head;
2130                         p = p->next;
2131                 }
2132                 struct symdef def = find_sym(p, s, 0);
2133                 if (!def.sym) goto failed;
2134                 if ((def.sym->st_info&0xf) == STT_TLS)
2135                         return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET});
2136                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
2137                         return def.dso->funcdescs + (def.sym - def.dso->syms);
2138                 return laddr(def.dso, def.sym->st_value);
2139         }
2140         if (__dl_invalid_handle(p))
2141                 return 0;
2142         if ((ght = p->ghashtab)) {
2143                 gh = gnu_hash(s);
2144                 sym = gnu_lookup(gh, ght, p, s);
2145         } else {
2146                 h = sysv_hash(s);
2147                 sym = sysv_lookup(s, h, p);
2148         }
2149         if (sym && (sym->st_info&0xf) == STT_TLS)
2150                 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value-DTP_OFFSET});
2151         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
2152                 return p->funcdescs + (sym - p->syms);
2153         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
2154                 return laddr(p, sym->st_value);
2155         for (i=0; p->deps[i]; i++) {
2156                 if ((ght = p->deps[i]->ghashtab)) {
2157                         if (!gh) gh = gnu_hash(s);
2158                         sym = gnu_lookup(gh, ght, p->deps[i], s);
2159                 } else {
2160                         if (!h) h = sysv_hash(s);
2161                         sym = sysv_lookup(s, h, p->deps[i]);
2162                 }
2163                 if (sym && (sym->st_info&0xf) == STT_TLS)
2164                         return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value-DTP_OFFSET});
2165                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
2166                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
2167                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
2168                         return laddr(p->deps[i], sym->st_value);
2169         }
2170 failed:
2171         error("Symbol not found: %s", s);
2172         return 0;
2173 }
2174
2175 int dladdr(const void *addr_arg, Dl_info *info)
2176 {
2177         size_t addr = (size_t)addr_arg;
2178         struct dso *p;
2179         Sym *sym, *bestsym;
2180         uint32_t nsym;
2181         char *strings;
2182         size_t best = 0;
2183         size_t besterr = -1;
2184
2185         pthread_rwlock_rdlock(&lock);
2186         p = addr2dso(addr);
2187         pthread_rwlock_unlock(&lock);
2188
2189         if (!p) return 0;
2190
2191         sym = p->syms;
2192         strings = p->strings;
2193         nsym = count_syms(p);
2194
2195         if (DL_FDPIC) {
2196                 size_t idx = (addr-(size_t)p->funcdescs)
2197                         / sizeof(*p->funcdescs);
2198                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
2199                         best = (size_t)(p->funcdescs + idx);
2200                         bestsym = sym + idx;
2201                         besterr = 0;
2202                 }
2203         }
2204
2205         if (!best) for (; nsym; nsym--, sym++) {
2206                 if (sym->st_value
2207                  && (1<<(sym->st_info&0xf) & OK_TYPES)
2208                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
2209                         size_t symaddr = (size_t)laddr(p, sym->st_value);
2210                         if (symaddr > addr || symaddr <= best)
2211                                 continue;
2212                         best = symaddr;
2213                         bestsym = sym;
2214                         besterr = addr - symaddr;
2215                         if (addr == symaddr)
2216                                 break;
2217                 }
2218         }
2219
2220         if (bestsym && besterr > bestsym->st_size-1) {
2221                 best = 0;
2222                 bestsym = 0;
2223         }
2224
2225         info->dli_fname = p->name;
2226         info->dli_fbase = p->map;
2227
2228         if (!best) {
2229                 info->dli_sname = 0;
2230                 info->dli_saddr = 0;
2231                 return 1;
2232         }
2233
2234         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2235                 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2236         info->dli_sname = strings + bestsym->st_name;
2237         info->dli_saddr = (void *)best;
2238
2239         return 1;
2240 }
2241
2242 hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2243 {
2244         void *res;
2245         pthread_rwlock_rdlock(&lock);
2246         res = do_dlsym(p, s, ra);
2247         pthread_rwlock_unlock(&lock);
2248         return res;
2249 }
2250
2251 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2252 {
2253         struct dso *current;
2254         struct dl_phdr_info info;
2255         int ret = 0;
2256         for(current = head; current;) {
2257                 info.dlpi_addr      = (uintptr_t)current->base;
2258                 info.dlpi_name      = current->name;
2259                 info.dlpi_phdr      = current->phdr;
2260                 info.dlpi_phnum     = current->phnum;
2261                 info.dlpi_adds      = gencnt;
2262                 info.dlpi_subs      = 0;
2263                 info.dlpi_tls_modid = current->tls_id;
2264                 info.dlpi_tls_data  = current->tls.image;
2265
2266                 ret = (callback)(&info, sizeof (info), data);
2267
2268                 if (ret != 0) break;
2269
2270                 pthread_rwlock_rdlock(&lock);
2271                 current = current->next;
2272                 pthread_rwlock_unlock(&lock);
2273         }
2274         return ret;
2275 }
2276
2277 static void error(const char *fmt, ...)
2278 {
2279         va_list ap;
2280         va_start(ap, fmt);
2281         if (!runtime) {
2282                 vdprintf(2, fmt, ap);
2283                 dprintf(2, "\n");
2284                 ldso_fail = 1;
2285                 va_end(ap);
2286                 return;
2287         }
2288         __dl_vseterr(fmt, ap);
2289         va_end(ap);
2290 }