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

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