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
  23 static int errflag;
  24 static char errbuf[128];
  25
  26 #ifdef SHARED
  27
  28 #if ULONG_MAX == 0xffffffff
  29 typedef Elf32_Ehdr Ehdr;
  30 typedef Elf32_Phdr Phdr;
  31 typedef Elf32_Sym Sym;
  32 #define R_TYPE(x) ((x)&255)
  33 #define R_SYM(x) ((x)>>8)
  34 #else
  35 typedef Elf64_Ehdr Ehdr;
  36 typedef Elf64_Phdr Phdr;
  37 typedef Elf64_Sym Sym;
  38 #define R_TYPE(x) ((x)&0xffffffff)
  39 #define R_SYM(x) ((x)>>32)
  40 #endif
  41
  42 #define MAXP2(a,b) (-(-(a)&-(b)))
  43 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  44
  45 struct debug {
  46         int ver;
  47         void *head;
  48         void (*bp)(void);
  49         int state;
  50         void *base;
  51 };
  52
  53 struct td_index {
  54         size_t args[2];
  55         struct td_index *next;
  56 };
  57
  58 struct dso {
  59         unsigned char *base;
  60         char *name;
  61         size_t *dynv;
  62         struct dso *next, *prev;
  63
  64         Phdr *phdr;
  65         int phnum;
  66         size_t phentsize;
  67         int refcnt;
  68         Sym *syms;
  69         uint32_t *hashtab;
  70         uint32_t *ghashtab;
  71         int16_t *versym;
  72         char *strings;
  73         unsigned char *map;
  74         size_t map_len;
  75         dev_t dev;
  76         ino_t ino;
  77         signed char global;
  78         char relocated;
  79         char constructed;
  80         char kernel_mapped;
  81         struct dso **deps, *needed_by;
  82         char *rpath_orig, *rpath;
  83         void *tls_image;
  84         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  85         size_t relro_start, relro_end;
  86         void **new_dtv;
  87         unsigned char *new_tls;
  88         int new_dtv_idx, new_tls_idx;
  89         struct td_index *td_index;
  90         struct dso *fini_next;
  91         char *shortname;
  92         char buf[];
  93 };
  94
  95 struct symdef {
  96         Sym *sym;
  97         struct dso *dso;
  98 };
  99
 100 enum {
 101         REL_ERR,
 102         REL_SYMBOLIC,
 103         REL_GOT,
 104         REL_PLT,
 105         REL_RELATIVE,
 106         REL_OFFSET,
 107         REL_OFFSET32,
 108         REL_COPY,
 109         REL_SYM_OR_REL,
 110         REL_TLS, /* everything past here is TLS */
 111         REL_DTPMOD,
 112         REL_DTPOFF,
 113         REL_TPOFF,
 114         REL_TPOFF_NEG,
 115         REL_TLSDESC,
 116 };
 117
 118 #include "reloc.h"
 119
 120 int __init_tp(void *);
 121 void __init_libc(char **, char *);
 122
 123 const char *__libc_get_version(void);
 124
 125 static struct dso *head, *tail, *ldso, *fini_head;
 126 static char *env_path, *sys_path;
 127 static unsigned long long gencnt;
 128 static int runtime;
 129 static int ldd_mode;
 130 static int ldso_fail;
 131 static int noload;
 132 static jmp_buf *rtld_fail;
 133 static pthread_rwlock_t lock;
 134 static struct debug debug;
 135 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
 136 static size_t static_tls_cnt;
 137 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 138 static long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)];
 139
 140 struct debug *_dl_debug_addr = &debug;
 141
 142 #define AUX_CNT 38
 143 #define DYN_CNT 34
 144
 145 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 146 {
 147         memset(a, 0, cnt*sizeof(size_t));
 148         for (; v[0]; v+=2) if (v[0]<cnt) {
 149                 a[0] |= 1ULL<<v[0];
 150                 a[v[0]] = v[1];
 151         }
 152 }
 153
 154 static int search_vec(size_t *v, size_t *r, size_t key)
 155 {
 156         for (; v[0]!=key; v+=2)
 157                 if (!v[0]) return 0;
 158         *r = v[1];
 159         return 1;
 160 }
 161
 162 static void error(const char *fmt, ...)
 163 {
 164         va_list ap;
 165         va_start(ap, fmt);
 166         vsnprintf(errbuf, sizeof errbuf, fmt, ap);
 167         va_end(ap);
 168         if (runtime) longjmp(*rtld_fail, 1);
 169         dprintf(2, "%s\n", errbuf);
 170         ldso_fail = 1;
 171 }
 172
 173 static uint32_t sysv_hash(const char *s0)
 174 {
 175         const unsigned char *s = (void *)s0;
 176         uint_fast32_t h = 0;
 177         while (*s) {
 178                 h = 16*h + *s++;
 179                 h ^= h>>24 & 0xf0;
 180         }
 181         return h & 0xfffffff;
 182 }
 183
 184 static uint32_t gnu_hash(const char *s0)
 185 {
 186         const unsigned char *s = (void *)s0;
 187         uint_fast32_t h = 5381;
 188         for (; *s; s++)
 189                 h = h*33 + *s;
 190         return h;
 191 }
 192
 193 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 194 {
 195         size_t i;
 196         Sym *syms = dso->syms;
 197         uint32_t *hashtab = dso->hashtab;
 198         char *strings = dso->strings;
 199         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 200                 if ((!dso->versym || dso->versym[i] >= 0)
 201                     && (!strcmp(s, strings+syms[i].st_name)))
 202                         return syms+i;
 203         }
 204         return 0;
 205 }
 206
 207 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 208 {
 209         Sym *syms = dso->syms;
 210         char *strings = dso->strings;
 211         uint32_t *hashtab = dso->ghashtab;
 212         uint32_t nbuckets = hashtab[0];
 213         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 214         uint32_t h2;
 215         uint32_t *hashval;
 216         uint32_t i = buckets[h1 % nbuckets];
 217
 218         if (!i) return 0;
 219
 220         hashval = buckets + nbuckets + (i - hashtab[1]);
 221
 222         for (h1 |= 1; ; i++) {
 223                 h2 = *hashval++;
 224                 if ((!dso->versym || dso->versym[i] >= 0)
 225                     && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
 226                         return syms+i;
 227                 if (h2 & 1) break;
 228         }
 229
 230         return 0;
 231 }
 232
 233 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 234 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 235
 236 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 237 {
 238         uint32_t h = 0, gh = 0;
 239         struct symdef def = {0};
 240         for (; dso; dso=dso->next) {
 241                 Sym *sym;
 242                 if (!dso->global) continue;
 243                 if (dso->ghashtab) {
 244                         if (!gh) gh = gnu_hash(s);
 245                         sym = gnu_lookup(s, gh, dso);
 246                 } else {
 247                         if (!h) h = sysv_hash(s);
 248                         sym = sysv_lookup(s, h, dso);
 249                 }
 250                 if (!sym) continue;
 251                 if (!sym->st_shndx)
 252                         if (need_def || (sym->st_info&0xf) == STT_TLS)
 253                                 continue;
 254                 if (!sym->st_value)
 255                         if ((sym->st_info&0xf) != STT_TLS)
 256                                 continue;
 257                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 258                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 259
 260                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 261                 def.sym = sym;
 262                 def.dso = dso;
 263                 if (sym->st_info>>4 == STB_GLOBAL) break;
 264         }
 265         return def;
 266 }
 267
 268 #define NO_INLINE_ADDEND (1<<REL_COPY | 1<<REL_GOT | 1<<REL_PLT)
 269
 270 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 271
 272 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 273 {
 274         unsigned char *base = dso->base;
 275         Sym *syms = dso->syms;
 276         char *strings = dso->strings;
 277         Sym *sym;
 278         const char *name;
 279         void *ctx;
 280         int astype, type;
 281         int sym_index;
 282         struct symdef def;
 283         size_t *reloc_addr;
 284         size_t sym_val;
 285         size_t tls_val;
 286         size_t addend;
 287
 288         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 289                 astype = R_TYPE(rel[1]);
 290                 if (!astype) continue;
 291                 type = remap_rel(astype);
 292                 if (!type) {
 293                         error("Error relocating %s: unsupported relocation type %d",
 294                                 dso->name, astype);
 295                         continue;
 296                 }
 297                 sym_index = R_SYM(rel[1]);
 298                 reloc_addr = (void *)(base + rel[0]);
 299                 if (sym_index) {
 300                         sym = syms + sym_index;
 301                         name = strings + sym->st_name;
 302                         ctx = type==REL_COPY ? head->next : head;
 303                         def = find_sym(ctx, name, type==REL_PLT);
 304                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 305                             || sym->st_info>>4 != STB_WEAK)) {
 306                                 error("Error relocating %s: %s: symbol not found",
 307                                         dso->name, name);
 308                                 continue;
 309                         }
 310                 } else {
 311                         sym = 0;
 312                         def.sym = 0;
 313                         def.dso = dso;
 314                 }
 315
 316                 addend = stride>2 ? rel[2]
 317                         : (1<<type & NO_INLINE_ADDEND) ? 0
 318                         : *reloc_addr;
 319
 320                 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
 321                 tls_val = def.sym ? def.sym->st_value : 0;
 322
 323                 switch(type) {
 324                 case REL_OFFSET:
 325                         addend -= (size_t)reloc_addr;
 326                 case REL_SYMBOLIC:
 327                 case REL_GOT:
 328                 case REL_PLT:
 329                         *reloc_addr = sym_val + addend;
 330                         break;
 331                 case REL_RELATIVE:
 332                         *reloc_addr = (size_t)base + addend;
 333                         break;
 334                 case REL_SYM_OR_REL:
 335                         if (sym) *reloc_addr = sym_val + addend;
 336                         else *reloc_addr = (size_t)base + addend;
 337                         break;
 338                 case REL_COPY:
 339                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 340                         break;
 341                 case REL_OFFSET32:
 342                         *(uint32_t *)reloc_addr = sym_val + addend
 343                                 - (size_t)reloc_addr;
 344                         break;
 345                 case REL_DTPMOD:
 346                         *reloc_addr = def.dso->tls_id;
 347                         break;
 348                 case REL_DTPOFF:
 349                         *reloc_addr = tls_val + addend;
 350                         break;
 351 #ifdef TLS_ABOVE_TP
 352                 case REL_TPOFF:
 353                         *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
 354                         break;
 355 #else
 356                 case REL_TPOFF:
 357                         *reloc_addr = tls_val - def.dso->tls_offset + addend;
 358                         break;
 359                 case REL_TPOFF_NEG:
 360                         *reloc_addr = def.dso->tls_offset - tls_val + addend;
 361                         break;
 362 #endif
 363                 case REL_TLSDESC:
 364                         if (stride<3) addend = reloc_addr[1];
 365                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 366                                 struct td_index *new = malloc(sizeof *new);
 367                                 if (!new) error(
 368                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 369                                         dso->name, sym ? name : "(local)" );
 370                                 new->next = dso->td_index;
 371                                 dso->td_index = new;
 372                                 new->args[0] = def.dso->tls_id;
 373                                 new->args[1] = tls_val + addend;
 374                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 375                                 reloc_addr[1] = (size_t)new;
 376                         } else {
 377                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 378 #ifdef TLS_ABOVE_TP
 379                                 reloc_addr[1] = tls_val + def.dso->tls_offset
 380                                         + TPOFF_K + addend;
 381 #else
 382                                 reloc_addr[1] = tls_val - def.dso->tls_offset
 383                                         + addend;
 384 #endif
 385                         }
 386                         break;
 387                 }
 388         }
 389 }
 390
 391 /* A huge hack: to make up for the wastefulness of shared libraries
 392  * needing at least a page of dirty memory even if they have no global
 393  * data, we reclaim the gaps at the beginning and end of writable maps
 394  * and "donate" them to the heap by setting up minimal malloc
 395  * structures and then freeing them. */
 396
 397 static void reclaim(struct dso *dso, size_t start, size_t end)
 398 {
 399         size_t *a, *z;
 400         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 401         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 402         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 403         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 404         if (start>end || end-start < 4*sizeof(size_t)) return;
 405         a = (size_t *)(dso->base + start);
 406         z = (size_t *)(dso->base + end);
 407         a[-2] = 1;
 408         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 409         z[1] = 1;
 410         free(a);
 411 }
 412
 413 static void reclaim_gaps(struct dso *dso)
 414 {
 415         Phdr *ph = dso->phdr;
 416         size_t phcnt = dso->phnum;
 417
 418         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 419                 if (ph->p_type!=PT_LOAD) continue;
 420                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 421                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 422                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 423                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 424         }
 425 }
 426
 427 static void *map_library(int fd, struct dso *dso)
 428 {
 429         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 430         void *allocated_buf=0;
 431         size_t phsize;
 432         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 433         size_t this_min, this_max;
 434         off_t off_start;
 435         Ehdr *eh;
 436         Phdr *ph, *ph0;
 437         unsigned prot;
 438         unsigned char *map=MAP_FAILED, *base;
 439         size_t dyn=0;
 440         size_t tls_image=0;
 441         size_t i;
 442
 443         ssize_t l = read(fd, buf, sizeof buf);
 444         eh = buf;
 445         if (l<0) return 0;
 446         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 447                 goto noexec;
 448         phsize = eh->e_phentsize * eh->e_phnum;
 449         if (phsize > sizeof buf - sizeof *eh) {
 450                 allocated_buf = malloc(phsize);
 451                 if (!allocated_buf) return 0;
 452                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 453                 if (l < 0) goto error;
 454                 if (l != phsize) goto noexec;
 455                 ph = ph0 = allocated_buf;
 456         } else if (eh->e_phoff + phsize > l) {
 457                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 458                 if (l < 0) goto error;
 459                 if (l != phsize) goto noexec;
 460                 ph = ph0 = (void *)(buf + 1);
 461         } else {
 462                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 463         }
 464         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 465                 if (ph->p_type == PT_DYNAMIC) {
 466                         dyn = ph->p_vaddr;
 467                 } else if (ph->p_type == PT_TLS) {
 468                         tls_image = ph->p_vaddr;
 469                         dso->tls_align = ph->p_align;
 470                         dso->tls_len = ph->p_filesz;
 471                         dso->tls_size = ph->p_memsz;
 472                 } else if (ph->p_type == PT_GNU_RELRO) {
 473                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 474                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 475                 }
 476                 if (ph->p_type != PT_LOAD) continue;
 477                 if (ph->p_vaddr < addr_min) {
 478                         addr_min = ph->p_vaddr;
 479                         off_start = ph->p_offset;
 480                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 481                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 482                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 483                 }
 484                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 485                         addr_max = ph->p_vaddr+ph->p_memsz;
 486                 }
 487         }
 488         if (!dyn) goto noexec;
 489         addr_max += PAGE_SIZE-1;
 490         addr_max &= -PAGE_SIZE;
 491         addr_min &= -PAGE_SIZE;
 492         off_start &= -PAGE_SIZE;
 493         map_len = addr_max - addr_min + off_start;
 494         /* The first time, we map too much, possibly even more than
 495          * the length of the file. This is okay because we will not
 496          * use the invalid part; we just need to reserve the right
 497          * amount of virtual address space to map over later. */
 498         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 499         if (map==MAP_FAILED) goto error;
 500         /* If the loaded file is not relocatable and the requested address is
 501          * not available, then the load operation must fail. */
 502         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 503                 errno = EBUSY;
 504                 goto error;
 505         }
 506         base = map - addr_min;
 507         dso->phdr = 0;
 508         dso->phnum = 0;
 509         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 510                 if (ph->p_type != PT_LOAD) continue;
 511                 /* Check if the programs headers are in this load segment, and
 512                  * if so, record the address for use by dl_iterate_phdr. */
 513                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 514                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 515                         dso->phdr = (void *)(base + ph->p_vaddr
 516                                 + (eh->e_phoff-ph->p_offset));
 517                         dso->phnum = eh->e_phnum;
 518                         dso->phentsize = eh->e_phentsize;
 519                 }
 520                 /* Reuse the existing mapping for the lowest-address LOAD */
 521                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 522                 this_min = ph->p_vaddr & -PAGE_SIZE;
 523                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 524                 off_start = ph->p_offset & -PAGE_SIZE;
 525                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 526                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 527                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 528                 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 529                         goto error;
 530                 if (ph->p_memsz > ph->p_filesz) {
 531                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 532                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 533                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 534                         if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
 535                                 goto error;
 536                 }
 537         }
 538         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 539                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 540                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
 541                                 goto error;
 542                         break;
 543                 }
 544         dso->map = map;
 545         dso->map_len = map_len;
 546         dso->base = base;
 547         dso->dynv = (void *)(base+dyn);
 548         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 549         if (!runtime) reclaim_gaps(dso);
 550         free(allocated_buf);
 551         return map;
 552 noexec:
 553         errno = ENOEXEC;
 554 error:
 555         if (map!=MAP_FAILED) munmap(map, map_len);
 556         free(allocated_buf);
 557         return 0;
 558 }
 559
 560 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 561 {
 562         size_t l;
 563         int fd;
 564         for (;;) {
 565                 s += strspn(s, ":\n");
 566                 l = strcspn(s, ":\n");
 567                 if (l-1 >= INT_MAX) return -1;
 568                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
 569                         continue;
 570                 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 571                 s += l;
 572         }
 573 }
 574
 575 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 576 {
 577         size_t n, l;
 578         const char *s, *t, *origin;
 579         char *d;
 580         if (p->rpath) return 0;
 581         if (!p->rpath_orig) return -1;
 582         if (!strchr(p->rpath_orig, '$')) {
 583                 p->rpath = p->rpath_orig;
 584                 return 0;
 585         }
 586         n = 0;
 587         s = p->rpath_orig;
 588         while ((t=strchr(s, '$'))) {
 589                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 590                         return -1;
 591                 s = t+1;
 592                 n++;
 593         }
 594         if (n > SSIZE_MAX/PATH_MAX) return -1;
 595
 596         if (p->kernel_mapped) {
 597                 /* $ORIGIN searches cannot be performed for the main program
 598                  * when it is suid/sgid/AT_SECURE. This is because the
 599                  * pathname is under the control of the caller of execve.
 600                  * For libraries, however, $ORIGIN can be processed safely
 601                  * since the library's pathname came from a trusted source
 602                  * (either system paths or a call to dlopen). */
 603                 if (libc.secure)
 604                         return -1;
 605                 l = readlink("/proc/self/exe", buf, buf_size);
 606                 if (l >= buf_size)
 607                         return -1;
 608                 buf[l] = 0;
 609                 origin = buf;
 610         } else {
 611                 origin = p->name;
 612         }
 613         t = strrchr(origin, '/');
 614         l = t ? t-origin : 0;
 615         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 616         if (!p->rpath) return -1;
 617
 618         d = p->rpath;
 619         s = p->rpath_orig;
 620         while ((t=strchr(s, '$'))) {
 621                 memcpy(d, s, t-s);
 622                 d += t-s;
 623                 memcpy(d, origin, l);
 624                 d += l;
 625                 /* It was determined previously that the '$' is followed
 626                  * either by "ORIGIN" or "{ORIGIN}". */
 627                 s = t + 7 + 2*(t[1]=='{');
 628         }
 629         strcpy(d, s);
 630         return 0;
 631 }
 632
 633 static void decode_dyn(struct dso *p)
 634 {
 635         size_t dyn[DYN_CNT] = {0};
 636         decode_vec(p->dynv, dyn, DYN_CNT);
 637         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 638         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 639         if (dyn[0]&(1<<DT_HASH))
 640                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 641         if (dyn[0]&(1<<DT_RPATH))
 642                 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
 643         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 644                 p->ghashtab = (void *)(p->base + *dyn);
 645         if (search_vec(p->dynv, dyn, DT_VERSYM))
 646                 p->versym = (void *)(p->base + *dyn);
 647 }
 648
 649 static struct dso *load_library(const char *name, struct dso *needed_by)
 650 {
 651         char buf[2*NAME_MAX+2];
 652         const char *pathname;
 653         unsigned char *map;
 654         struct dso *p, temp_dso = {0};
 655         int fd;
 656         struct stat st;
 657         size_t alloc_size;
 658         int n_th = 0;
 659         int is_self = 0;
 660
 661         /* Catch and block attempts to reload the implementation itself */
 662         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 663                 static const char *rp, reserved[] =
 664                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 665                 char *z = strchr(name, '.');
 666                 if (z) {
 667                         size_t l = z-name;
 668                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 669                         if (*rp) {
 670                                 if (ldd_mode) {
 671                                         /* Track which names have been resolved
 672                                          * and only report each one once. */
 673                                         static unsigned reported;
 674                                         unsigned mask = 1U<<(rp-reserved);
 675                                         if (!(reported & mask)) {
 676                                                 reported |= mask;
 677                                                 dprintf(1, "\t%s => %s (%p)\n",
 678                                                         name, ldso->name,
 679                                                         ldso->base);
 680                                         }
 681                                 }
 682                                 is_self = 1;
 683                         }
 684                 }
 685         }
 686         if (!strcmp(name, ldso->name)) is_self = 1;
 687         if (is_self) {
 688                 if (!ldso->prev) {
 689                         tail->next = ldso;
 690                         ldso->prev = tail;
 691                         tail = ldso->next ? ldso->next : ldso;
 692                 }
 693                 return ldso;
 694         }
 695         if (strchr(name, '/')) {
 696                 pathname = name;
 697                 fd = open(name, O_RDONLY|O_CLOEXEC);
 698         } else {
 699                 /* Search for the name to see if it's already loaded */
 700                 for (p=head->next; p; p=p->next) {
 701                         if (p->shortname && !strcmp(p->shortname, name)) {
 702                                 p->refcnt++;
 703                                 return p;
 704                         }
 705                 }
 706                 if (strlen(name) > NAME_MAX) return 0;
 707                 fd = -1;
 708                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 709                 for (p=needed_by; fd < 0 && p; p=p->needed_by)
 710                         if (!fixup_rpath(p, buf, sizeof buf))
 711                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 712                 if (fd < 0) {
 713                         if (!sys_path) {
 714                                 char *prefix = 0;
 715                                 size_t prefix_len;
 716                                 if (ldso->name[0]=='/') {
 717                                         char *s, *t, *z;
 718                                         for (s=t=z=ldso->name; *s; s++)
 719                                                 if (*s=='/') z=t, t=s;
 720                                         prefix_len = z-ldso->name;
 721                                         if (prefix_len < PATH_MAX)
 722                                                 prefix = ldso->name;
 723                                 }
 724                                 if (!prefix) {
 725                                         prefix = "";
 726                                         prefix_len = 0;
 727                                 }
 728                                 char etc_ldso_path[prefix_len + 1
 729                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 730                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 731                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 732                                         (int)prefix_len, prefix);
 733                                 FILE *f = fopen(etc_ldso_path, "rbe");
 734                                 if (f) {
 735                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 736                                                 free(sys_path);
 737                                                 sys_path = "";
 738                                         }
 739                                         fclose(f);
 740                                 } else if (errno != ENOENT) {
 741                                         sys_path = "";
 742                                 }
 743                         }
 744                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 745                         fd = path_open(name, sys_path, buf, sizeof buf);
 746                 }
 747                 pathname = buf;
 748         }
 749         if (fd < 0) return 0;
 750         if (fstat(fd, &st) < 0) {
 751                 close(fd);
 752                 return 0;
 753         }
 754         for (p=head->next; p; p=p->next) {
 755                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 756                         /* If this library was previously loaded with a
 757                          * pathname but a search found the same inode,
 758                          * setup its shortname so it can be found by name. */
 759                         if (!p->shortname && pathname != name)
 760                                 p->shortname = strrchr(p->name, '/')+1;
 761                         close(fd);
 762                         p->refcnt++;
 763                         return p;
 764                 }
 765         }
 766         map = noload ? 0 : map_library(fd, &temp_dso);
 767         close(fd);
 768         if (!map) return 0;
 769
 770         /* Allocate storage for the new DSO. When there is TLS, this
 771          * storage must include a reservation for all pre-existing
 772          * threads to obtain copies of both the new TLS, and an
 773          * extended DTV capable of storing an additional slot for
 774          * the newly-loaded DSO. */
 775         alloc_size = sizeof *p + strlen(pathname) + 1;
 776         if (runtime && temp_dso.tls_image) {
 777                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 778                         + sizeof(void *) * (tls_cnt+3);
 779                 n_th = libc.threads_minus_1 + 1;
 780                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 781                 else alloc_size += n_th * per_th;
 782         }
 783         p = calloc(1, alloc_size);
 784         if (!p) {
 785                 munmap(map, temp_dso.map_len);
 786                 return 0;
 787         }
 788         memcpy(p, &temp_dso, sizeof temp_dso);
 789         decode_dyn(p);
 790         p->dev = st.st_dev;
 791         p->ino = st.st_ino;
 792         p->refcnt = 1;
 793         p->needed_by = needed_by;
 794         p->name = p->buf;
 795         strcpy(p->name, pathname);
 796         /* Add a shortname only if name arg was not an explicit pathname. */
 797         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 798         if (p->tls_image) {
 799                 if (runtime && !libc.has_thread_pointer) {
 800                         munmap(map, p->map_len);
 801                         free(p);
 802                         errno = ENOSYS;
 803                         return 0;
 804                 }
 805                 p->tls_id = ++tls_cnt;
 806                 tls_align = MAXP2(tls_align, p->tls_align);
 807 #ifdef TLS_ABOVE_TP
 808                 p->tls_offset = tls_offset + ( (tls_align-1) &
 809                         -(tls_offset + (uintptr_t)p->tls_image) );
 810                 tls_offset += p->tls_size;
 811 #else
 812                 tls_offset += p->tls_size + p->tls_align - 1;
 813                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 814                         & (p->tls_align-1);
 815                 p->tls_offset = tls_offset;
 816 #endif
 817                 p->new_dtv = (void *)(-sizeof(size_t) &
 818                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 819                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 820         }
 821
 822         tail->next = p;
 823         p->prev = tail;
 824         tail = p;
 825
 826         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 827
 828         return p;
 829 }
 830
 831 static void load_deps(struct dso *p)
 832 {
 833         size_t i, ndeps=0;
 834         struct dso ***deps = &p->deps, **tmp, *dep;
 835         for (; p; p=p->next) {
 836                 for (i=0; p->dynv[i]; i+=2) {
 837                         if (p->dynv[i] != DT_NEEDED) continue;
 838                         dep = load_library(p->strings + p->dynv[i+1], p);
 839                         if (!dep) {
 840                                 error("Error loading shared library %s: %m (needed by %s)",
 841                                         p->strings + p->dynv[i+1], p->name);
 842                                 continue;
 843                         }
 844                         if (runtime) {
 845                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 846                                 if (!tmp) longjmp(*rtld_fail, 1);
 847                                 tmp[ndeps++] = dep;
 848                                 tmp[ndeps] = 0;
 849                                 *deps = tmp;
 850                         }
 851                 }
 852         }
 853 }
 854
 855 static void load_preload(char *s)
 856 {
 857         int tmp;
 858         char *z;
 859         for (z=s; *z; s=z) {
 860                 for (   ; *s && isspace(*s); s++);
 861                 for (z=s; *z && !isspace(*z); z++);
 862                 tmp = *z;
 863                 *z = 0;
 864                 load_library(s, 0);
 865                 *z = tmp;
 866         }
 867 }
 868
 869 static void make_global(struct dso *p)
 870 {
 871         for (; p; p=p->next) p->global = 1;
 872 }
 873
 874 static void reloc_all(struct dso *p)
 875 {
 876         size_t dyn[DYN_CNT] = {0};
 877         for (; p; p=p->next) {
 878                 if (p->relocated) continue;
 879                 decode_vec(p->dynv, dyn, DYN_CNT);
 880 #ifdef NEED_ARCH_RELOCS
 881                 do_arch_relocs(p, head);
 882 #endif
 883                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 884                         2+(dyn[DT_PLTREL]==DT_RELA));
 885                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 886                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 887
 888                 if (p->relro_start != p->relro_end &&
 889                     mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
 890                         error("Error relocating %s: RELRO protection failed: %m",
 891                                 p->name);
 892                 }
 893
 894                 p->relocated = 1;
 895         }
 896 }
 897
 898 static void kernel_mapped_dso(struct dso *p)
 899 {
 900         size_t min_addr = -1, max_addr = 0, cnt;
 901         Phdr *ph = p->phdr;
 902         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
 903                 if (ph->p_type == PT_DYNAMIC) {
 904                         p->dynv = (void *)(p->base + ph->p_vaddr);
 905                 } else if (ph->p_type == PT_GNU_RELRO) {
 906                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
 907                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 908                 }
 909                 if (ph->p_type != PT_LOAD) continue;
 910                 if (ph->p_vaddr < min_addr)
 911                         min_addr = ph->p_vaddr;
 912                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 913                         max_addr = ph->p_vaddr+ph->p_memsz;
 914         }
 915         min_addr &= -PAGE_SIZE;
 916         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 917         p->map = p->base + min_addr;
 918         p->map_len = max_addr - min_addr;
 919         p->kernel_mapped = 1;
 920 }
 921
 922 static void do_fini()
 923 {
 924         struct dso *p;
 925         size_t dyn[DYN_CNT] = {0};
 926         for (p=fini_head; p; p=p->fini_next) {
 927                 if (!p->constructed) continue;
 928                 decode_vec(p->dynv, dyn, DYN_CNT);
 929                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
 930                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
 931                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
 932                         while (n--) ((void (*)(void))*--fn)();
 933                 }
 934 #ifndef NO_LEGACY_INITFINI
 935                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 936                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
 937 #endif
 938         }
 939 }
 940
 941 static void do_init_fini(struct dso *p)
 942 {
 943         size_t dyn[DYN_CNT] = {0};
 944         int need_locking = libc.threads_minus_1;
 945         /* Allow recursive calls that arise when a library calls
 946          * dlopen from one of its constructors, but block any
 947          * other threads until all ctors have finished. */
 948         if (need_locking) pthread_mutex_lock(&init_fini_lock);
 949         for (; p; p=p->prev) {
 950                 if (p->constructed) continue;
 951                 p->constructed = 1;
 952                 decode_vec(p->dynv, dyn, DYN_CNT);
 953                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
 954                         p->fini_next = fini_head;
 955                         fini_head = p;
 956                 }
 957 #ifndef NO_LEGACY_INITFINI
 958                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 959                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
 960 #endif
 961                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
 962                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
 963                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
 964                         while (n--) ((void (*)(void))*fn++)();
 965                 }
 966                 if (!need_locking && libc.threads_minus_1) {
 967                         need_locking = 1;
 968                         pthread_mutex_lock(&init_fini_lock);
 969                 }
 970         }
 971         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 972 }
 973
 974 void _dl_debug_state(void)
 975 {
 976 }
 977
 978 void __reset_tls()
 979 {
 980         pthread_t self = __pthread_self();
 981         struct dso *p;
 982         for (p=head; p; p=p->next) {
 983                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
 984                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
 985                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
 986                         p->tls_size - p->tls_len);
 987                 if (p->tls_id == (size_t)self->dtv[0]) break;
 988         }
 989 }
 990
 991 void *__copy_tls(unsigned char *mem)
 992 {
 993         pthread_t td;
 994         struct dso *p;
 995
 996         void **dtv = (void *)mem;
 997         dtv[0] = (void *)tls_cnt;
 998         if (!tls_cnt) {
 999                 td = (void *)(dtv+1);
1000                 td->dtv = dtv;
1001                 return td;
1002         }
1003
1004 #ifdef TLS_ABOVE_TP
1005         mem += sizeof(void *) * (tls_cnt+1);
1006         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1007         td = (pthread_t)mem;
1008         mem += sizeof(struct pthread);
1009
1010         for (p=head; p; p=p->next) {
1011                 if (!p->tls_id) continue;
1012                 dtv[p->tls_id] = mem + p->tls_offset;
1013                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1014         }
1015 #else
1016         mem += libc.tls_size - sizeof(struct pthread);
1017         mem -= (uintptr_t)mem & (tls_align-1);
1018         td = (pthread_t)mem;
1019
1020         for (p=head; p; p=p->next) {
1021                 if (!p->tls_id) continue;
1022                 dtv[p->tls_id] = mem - p->tls_offset;
1023                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1024         }
1025 #endif
1026         td->dtv = dtv;
1027         return td;
1028 }
1029
1030 void *__tls_get_new(size_t *v)
1031 {
1032         pthread_t self = __pthread_self();
1033
1034         /* Block signals to make accessing new TLS async-signal-safe */
1035         sigset_t set;
1036         __block_all_sigs(&set);
1037         if (v[0]<=(size_t)self->dtv[0]) {
1038                 __restore_sigs(&set);
1039                 return (char *)self->dtv[v[0]]+v[1];
1040         }
1041
1042         /* This is safe without any locks held because, if the caller
1043          * is able to request the Nth entry of the DTV, the DSO list
1044          * must be valid at least that far out and it was synchronized
1045          * at program startup or by an already-completed call to dlopen. */
1046         struct dso *p;
1047         for (p=head; p->tls_id != v[0]; p=p->next);
1048
1049         /* Get new DTV space from new DSO if needed */
1050         if (v[0] > (size_t)self->dtv[0]) {
1051                 void **newdtv = p->new_dtv +
1052                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1053                 memcpy(newdtv, self->dtv,
1054                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1055                 newdtv[0] = (void *)v[0];
1056                 self->dtv = newdtv;
1057         }
1058
1059         /* Get new TLS memory from all new DSOs up to the requested one */
1060         unsigned char *mem;
1061         for (p=head; ; p=p->next) {
1062                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1063                 mem = p->new_tls + (p->tls_size + p->tls_align)
1064                         * a_fetch_add(&p->new_tls_idx,1);
1065                 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1066                         & (p->tls_align-1);
1067                 self->dtv[p->tls_id] = mem;
1068                 memcpy(mem, p->tls_image, p->tls_len);
1069                 if (p->tls_id == v[0]) break;
1070         }
1071         __restore_sigs(&set);
1072         return mem + v[1];
1073 }
1074
1075 static void update_tls_size()
1076 {
1077         libc.tls_size = ALIGN(
1078                 (1+tls_cnt) * sizeof(void *) +
1079                 tls_offset +
1080                 sizeof(struct pthread) +
1081                 tls_align * 2,
1082         tls_align);
1083 }
1084
1085 void *__dynlink(int argc, char **argv)
1086 {
1087         size_t aux[AUX_CNT] = {0};
1088         size_t i;
1089         Phdr *phdr;
1090         Ehdr *ehdr;
1091         static struct dso builtin_dsos[3];
1092         struct dso *const app = builtin_dsos+0;
1093         struct dso *const lib = builtin_dsos+1;
1094         struct dso *const vdso = builtin_dsos+2;
1095         char *env_preload=0;
1096         size_t vdso_base;
1097         size_t *auxv;
1098         char **envp = argv+argc+1;
1099         void *initial_tls;
1100
1101         /* Find aux vector just past environ[] */
1102         for (i=argc+1; argv[i]; i++)
1103                 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
1104                         env_path = argv[i]+16;
1105                 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
1106                         env_preload = argv[i]+11;
1107         auxv = (void *)(argv+i+1);
1108
1109         decode_vec(auxv, aux, AUX_CNT);
1110
1111         /* Only trust user/env if kernel says we're not suid/sgid */
1112         if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1113           || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
1114                 env_path = 0;
1115                 env_preload = 0;
1116                 libc.secure = 1;
1117         }
1118         libc.page_size = aux[AT_PAGESZ];
1119
1120         /* If the dynamic linker was invoked as a program itself, AT_BASE
1121          * will not be set. In that case, we assume the base address is
1122          * the start of the page containing the PHDRs; I don't know any
1123          * better approach... */
1124         if (!aux[AT_BASE]) {
1125                 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
1126                 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
1127         }
1128
1129         /* The dynamic linker load address is passed by the kernel
1130          * in the AUX vector, so this is easy. */
1131         lib->base = (void *)aux[AT_BASE];
1132         lib->name = lib->shortname = "libc.so";
1133         lib->global = 1;
1134         ehdr = (void *)lib->base;
1135         lib->phnum = ehdr->e_phnum;
1136         lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
1137         lib->phentsize = ehdr->e_phentsize;
1138         kernel_mapped_dso(lib);
1139         decode_dyn(lib);
1140
1141         if (aux[AT_PHDR]) {
1142                 size_t interp_off = 0;
1143                 size_t tls_image = 0;
1144                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1145                 app->phdr = phdr = (void *)aux[AT_PHDR];
1146                 app->phnum = aux[AT_PHNUM];
1147                 app->phentsize = aux[AT_PHENT];
1148                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1149                         if (phdr->p_type == PT_PHDR)
1150                                 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1151                         else if (phdr->p_type == PT_INTERP)
1152                                 interp_off = (size_t)phdr->p_vaddr;
1153                         else if (phdr->p_type == PT_TLS) {
1154                                 tls_image = phdr->p_vaddr;
1155                                 app->tls_len = phdr->p_filesz;
1156                                 app->tls_size = phdr->p_memsz;
1157                                 app->tls_align = phdr->p_align;
1158                         }
1159                 }
1160                 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
1161                 if (interp_off) lib->name = (char *)app->base + interp_off;
1162                 if ((aux[0] & (1UL<<AT_EXECFN))
1163                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1164                         app->name = (char *)aux[AT_EXECFN];
1165                 else
1166                         app->name = argv[0];
1167                 kernel_mapped_dso(app);
1168         } else {
1169                 int fd;
1170                 char *ldname = argv[0];
1171                 size_t l = strlen(ldname);
1172                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1173                 *argv++ = (void *)-1;
1174                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1175                         char *opt = argv[0]+2;
1176                         *argv++ = (void *)-1;
1177                         if (!*opt) {
1178                                 break;
1179                         } else if (!memcmp(opt, "list", 5)) {
1180                                 ldd_mode = 1;
1181                         } else if (!memcmp(opt, "library-path", 12)) {
1182                                 if (opt[12]=='=') env_path = opt+13;
1183                                 else if (opt[12]) *argv = 0;
1184                                 else if (*argv) env_path = *argv++;
1185                         } else if (!memcmp(opt, "preload", 7)) {
1186                                 if (opt[7]=='=') env_preload = opt+8;
1187                                 else if (opt[7]) *argv = 0;
1188                                 else if (*argv) env_preload = *argv++;
1189                         } else {
1190                                 argv[0] = 0;
1191                         }
1192                         argv[-1] = (void *)-1;
1193                 }
1194                 if (!argv[0]) {
1195                         dprintf(2, "musl libc\n"
1196                                 "Version %s\n"
1197                                 "Dynamic Program Loader\n"
1198                                 "Usage: %s [options] [--] pathname%s\n",
1199                                 __libc_get_version(), ldname,
1200                                 ldd_mode ? "" : " [args]");
1201                         _exit(1);
1202                 }
1203                 fd = open(argv[0], O_RDONLY);
1204                 if (fd < 0) {
1205                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1206                         _exit(1);
1207                 }
1208                 runtime = 1;
1209                 ehdr = (void *)map_library(fd, app);
1210                 if (!ehdr) {
1211                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1212                         _exit(1);
1213                 }
1214                 runtime = 0;
1215                 close(fd);
1216                 lib->name = ldname;
1217                 app->name = argv[0];
1218                 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
1219                 /* Find the name that would have been used for the dynamic
1220                  * linker had ldd not taken its place. */
1221                 if (ldd_mode) {
1222                         for (i=0; i<app->phnum; i++) {
1223                                 if (app->phdr[i].p_type == PT_INTERP)
1224                                         lib->name = (void *)(app->base
1225                                                 + app->phdr[i].p_vaddr);
1226                         }
1227                         dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
1228                 }
1229         }
1230         if (app->tls_size) {
1231                 app->tls_id = tls_cnt = 1;
1232 #ifdef TLS_ABOVE_TP
1233                 app->tls_offset = 0;
1234                 tls_offset = app->tls_size
1235                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1236                         & (app->tls_align-1) );
1237 #else
1238                 tls_offset = app->tls_offset = app->tls_size
1239                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1240                         & (app->tls_align-1) );
1241 #endif
1242                 tls_align = MAXP2(tls_align, app->tls_align);
1243         }
1244         app->global = 1;
1245         decode_dyn(app);
1246
1247         /* Attach to vdso, if provided by the kernel */
1248         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1249                 ehdr = (void *)vdso_base;
1250                 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1251                 vdso->phnum = ehdr->e_phnum;
1252                 vdso->phentsize = ehdr->e_phentsize;
1253                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1254                         if (phdr->p_type == PT_DYNAMIC)
1255                                 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1256                         if (phdr->p_type == PT_LOAD)
1257                                 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1258                 }
1259                 vdso->name = "";
1260                 vdso->shortname = "linux-gate.so.1";
1261                 vdso->global = 1;
1262                 decode_dyn(vdso);
1263                 vdso->prev = lib;
1264                 lib->next = vdso;
1265         }
1266
1267         /* Initial dso chain consists only of the app. We temporarily
1268          * append the dynamic linker/libc so we can relocate it, then
1269          * restore the initial chain in preparation for loading third
1270          * party libraries (preload/needed). */
1271         head = tail = app;
1272         ldso = lib;
1273         app->next = lib;
1274         reloc_all(lib);
1275         app->next = 0;
1276
1277         /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1278
1279         /* Donate unused parts of app and library mapping to malloc */
1280         reclaim_gaps(app);
1281         reclaim_gaps(lib);
1282
1283         /* Load preload/needed libraries, add their symbols to the global
1284          * namespace, and perform all remaining relocations. The main
1285          * program must be relocated LAST since it may contain copy
1286          * relocations which depend on libraries' relocations. */
1287         if (env_preload) load_preload(env_preload);
1288         load_deps(app);
1289         make_global(app);
1290
1291 #ifndef DYNAMIC_IS_RO
1292         for (i=0; app->dynv[i]; i+=2)
1293                 if (app->dynv[i]==DT_DEBUG)
1294                         app->dynv[i+1] = (size_t)&debug;
1295 #endif
1296
1297         reloc_all(app->next);
1298         reloc_all(app);
1299
1300         update_tls_size();
1301         if (libc.tls_size > sizeof builtin_tls) {
1302                 initial_tls = calloc(libc.tls_size, 1);
1303                 if (!initial_tls) {
1304                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1305                                 argv[0], libc.tls_size);
1306                         _exit(127);
1307                 }
1308         } else {
1309                 initial_tls = builtin_tls;
1310         }
1311         if (__init_tp(__copy_tls(initial_tls)) < 0 && tls_cnt) {
1312                 dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]);
1313                 _exit(127);
1314         }
1315         static_tls_cnt = tls_cnt;
1316
1317         if (ldso_fail) _exit(127);
1318         if (ldd_mode) _exit(0);
1319
1320         /* Switch to runtime mode: any further failures in the dynamic
1321          * linker are a reportable failure rather than a fatal startup
1322          * error. If the dynamic loader (dlopen) will not be used, free
1323          * all memory used by the dynamic linker. */
1324         runtime = 1;
1325
1326         debug.ver = 1;
1327         debug.bp = _dl_debug_state;
1328         debug.head = head;
1329         debug.base = lib->base;
1330         debug.state = 0;
1331         _dl_debug_state();
1332
1333         __init_libc(envp, argv[0]);
1334         atexit(do_fini);
1335         errno = 0;
1336         do_init_fini(tail);
1337
1338         return (void *)aux[AT_ENTRY];
1339 }
1340
1341 void *dlopen(const char *file, int mode)
1342 {
1343         struct dso *volatile p, *orig_tail, *next;
1344         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1345         size_t i;
1346         int cs;
1347         jmp_buf jb;
1348
1349         if (!file) return head;
1350
1351         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1352         pthread_rwlock_wrlock(&lock);
1353         __inhibit_ptc();
1354
1355         p = 0;
1356         orig_tls_cnt = tls_cnt;
1357         orig_tls_offset = tls_offset;
1358         orig_tls_align = tls_align;
1359         orig_tail = tail;
1360         noload = mode & RTLD_NOLOAD;
1361
1362         rtld_fail = &jb;
1363         if (setjmp(*rtld_fail)) {
1364                 /* Clean up anything new that was (partially) loaded */
1365                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1366                         if (p->deps[i]->global < 0)
1367                                 p->deps[i]->global = 0;
1368                 for (p=orig_tail->next; p; p=next) {
1369                         next = p->next;
1370                         munmap(p->map, p->map_len);
1371                         while (p->td_index) {
1372                                 void *tmp = p->td_index->next;
1373                                 free(p->td_index);
1374                                 p->td_index = tmp;
1375                         }
1376                         free(p->deps);
1377                         free(p);
1378                 }
1379                 tls_cnt = orig_tls_cnt;
1380                 tls_offset = orig_tls_offset;
1381                 tls_align = orig_tls_align;
1382                 tail = orig_tail;
1383                 tail->next = 0;
1384                 p = 0;
1385                 errflag = 1;
1386                 goto end;
1387         } else p = load_library(file, head);
1388
1389         if (!p) {
1390                 snprintf(errbuf, sizeof errbuf, noload ?
1391                         "Library %s is not already loaded" :
1392                         "Error loading shared library %s: %m",
1393                         file);
1394                 errflag = 1;
1395                 goto end;
1396         }
1397
1398         /* First load handling */
1399         if (!p->deps) {
1400                 load_deps(p);
1401                 if (p->deps) for (i=0; p->deps[i]; i++)
1402                         if (!p->deps[i]->global)
1403                                 p->deps[i]->global = -1;
1404                 if (!p->global) p->global = -1;
1405                 reloc_all(p);
1406                 if (p->deps) for (i=0; p->deps[i]; i++)
1407                         if (p->deps[i]->global < 0)
1408                                 p->deps[i]->global = 0;
1409                 if (p->global < 0) p->global = 0;
1410         }
1411
1412         if (mode & RTLD_GLOBAL) {
1413                 if (p->deps) for (i=0; p->deps[i]; i++)
1414                         p->deps[i]->global = 1;
1415                 p->global = 1;
1416         }
1417
1418         update_tls_size();
1419         _dl_debug_state();
1420         orig_tail = tail;
1421 end:
1422         __release_ptc();
1423         if (p) gencnt++;
1424         pthread_rwlock_unlock(&lock);
1425         if (p) do_init_fini(orig_tail);
1426         pthread_setcancelstate(cs, 0);
1427         return p;
1428 }
1429
1430 static int invalid_dso_handle(void *h)
1431 {
1432         struct dso *p;
1433         for (p=head; p; p=p->next) if (h==p) return 0;
1434         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1435         errflag = 1;
1436         return 1;
1437 }
1438
1439 void *__tls_get_addr(size_t *);
1440
1441 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1442 {
1443         size_t i;
1444         uint32_t h = 0, gh = 0;
1445         Sym *sym;
1446         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1447                 if (p == RTLD_DEFAULT) {
1448                         p = head;
1449                 } else if (p == RTLD_NEXT) {
1450                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1451                         if (!p) p=head;
1452                         p = p->next;
1453                 }
1454                 struct symdef def = find_sym(p, s, 0);
1455                 if (!def.sym) goto failed;
1456                 if ((def.sym->st_info&0xf) == STT_TLS)
1457                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1458                 return def.dso->base + def.sym->st_value;
1459         }
1460         if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1461                 return 0;
1462         if (p->ghashtab) {
1463                 gh = gnu_hash(s);
1464                 sym = gnu_lookup(s, gh, p);
1465         } else {
1466                 h = sysv_hash(s);
1467                 sym = sysv_lookup(s, h, p);
1468         }
1469         if (sym && (sym->st_info&0xf) == STT_TLS)
1470                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1471         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1472                 return p->base + sym->st_value;
1473         if (p->deps) for (i=0; p->deps[i]; i++) {
1474                 if (p->deps[i]->ghashtab) {
1475                         if (!gh) gh = gnu_hash(s);
1476                         sym = gnu_lookup(s, gh, p->deps[i]);
1477                 } else {
1478                         if (!h) h = sysv_hash(s);
1479                         sym = sysv_lookup(s, h, p->deps[i]);
1480                 }
1481                 if (sym && (sym->st_info&0xf) == STT_TLS)
1482                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1483                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1484                         return p->deps[i]->base + sym->st_value;
1485         }
1486 failed:
1487         errflag = 1;
1488         snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1489         return 0;
1490 }
1491
1492 int __dladdr(const void *addr, Dl_info *info)
1493 {
1494         struct dso *p;
1495         Sym *sym;
1496         uint32_t nsym;
1497         char *strings;
1498         size_t i;
1499         void *best = 0;
1500         char *bestname;
1501
1502         pthread_rwlock_rdlock(&lock);
1503         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1504         pthread_rwlock_unlock(&lock);
1505
1506         if (!p) return 0;
1507
1508         sym = p->syms;
1509         strings = p->strings;
1510         if (p->hashtab) {
1511                 nsym = p->hashtab[1];
1512         } else {
1513                 uint32_t *buckets;
1514                 uint32_t *hashval;
1515                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1516                 sym += p->ghashtab[1];
1517                 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1518                         if (buckets[i] > nsym)
1519                                 nsym = buckets[i];
1520                 }
1521                 if (nsym) {
1522                         nsym -= p->ghashtab[1];
1523                         hashval = buckets + p->ghashtab[0] + nsym;
1524                         do nsym++;
1525                         while (!(*hashval++ & 1));
1526                 }
1527         }
1528
1529         for (; nsym; nsym--, sym++) {
1530                 if (sym->st_value
1531                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1532                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1533                         void *symaddr = p->base + sym->st_value;
1534                         if (symaddr > addr || symaddr < best)
1535                                 continue;
1536                         best = symaddr;
1537                         bestname = strings + sym->st_name;
1538                         if (addr == symaddr)
1539                                 break;
1540                 }
1541         }
1542
1543         if (!best) return 0;
1544
1545         info->dli_fname = p->name;
1546         info->dli_fbase = p->base;
1547         info->dli_sname = bestname;
1548         info->dli_saddr = best;
1549
1550         return 1;
1551 }
1552
1553 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1554 {
1555         void *res;
1556         pthread_rwlock_rdlock(&lock);
1557         res = do_dlsym(p, s, ra);
1558         pthread_rwlock_unlock(&lock);
1559         return res;
1560 }
1561
1562 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1563 {
1564         struct dso *current;
1565         struct dl_phdr_info info;
1566         int ret = 0;
1567         for(current = head; current;) {
1568                 info.dlpi_addr      = (uintptr_t)current->base;
1569                 info.dlpi_name      = current->name;
1570                 info.dlpi_phdr      = current->phdr;
1571                 info.dlpi_phnum     = current->phnum;
1572                 info.dlpi_adds      = gencnt;
1573                 info.dlpi_subs      = 0;
1574                 info.dlpi_tls_modid = current->tls_id;
1575                 info.dlpi_tls_data  = current->tls_image;
1576
1577                 ret = (callback)(&info, sizeof (info), data);
1578
1579                 if (ret != 0) break;
1580
1581                 pthread_rwlock_rdlock(&lock);
1582                 current = current->next;
1583                 pthread_rwlock_unlock(&lock);
1584         }
1585         return ret;
1586 }
1587 #else
1588 static int invalid_dso_handle(void *h)
1589 {
1590         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1591         errflag = 1;
1592         return 1;
1593 }
1594 void *dlopen(const char *file, int mode)
1595 {
1596         return 0;
1597 }
1598 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1599 {
1600         return 0;
1601 }
1602 int __dladdr (const void *addr, Dl_info *info)
1603 {
1604         return 0;
1605 }
1606 #endif
1607
1608 int __dlinfo(void *dso, int req, void *res)
1609 {
1610         if (invalid_dso_handle(dso)) return -1;
1611         if (req != RTLD_DI_LINKMAP) {
1612                 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1613                 errflag = 1;
1614                 return -1;
1615         }
1616         *(struct link_map **)res = dso;
1617         return 0;
1618 }
1619
1620 char *dlerror()
1621 {
1622         if (!errflag) return 0;
1623         errflag = 0;
1624         return errbuf;
1625 }
1626
1627 int dlclose(void *p)
1628 {
1629         return invalid_dso_handle(p);
1630 }