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

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <stdint.h>
   7 #include <elf.h>
   8 #include <sys/mman.h>
   9 #include <limits.h>
  10 #include <fcntl.h>
  11 #include <sys/stat.h>
  12 #include <errno.h>
  13 #include <link.h>
  14 #include <setjmp.h>
  15 #include <pthread.h>
  16 #include <ctype.h>
  17 #include <dlfcn.h>
  18 #include "pthread_impl.h"
  19 #include "libc.h"
  20
  21 static int errflag;
  22 static char errbuf[128];
  23
  24 #ifdef SHARED
  25
  26 #if ULONG_MAX == 0xffffffff
  27 typedef Elf32_Ehdr Ehdr;
  28 typedef Elf32_Phdr Phdr;
  29 typedef Elf32_Sym Sym;
  30 #define R_TYPE(x) ((x)&255)
  31 #define R_SYM(x) ((x)>>8)
  32 #else
  33 typedef Elf64_Ehdr Ehdr;
  34 typedef Elf64_Phdr Phdr;
  35 typedef Elf64_Sym Sym;
  36 #define R_TYPE(x) ((x)&0xffffffff)
  37 #define R_SYM(x) ((x)>>32)
  38 #endif
  39
  40 #define MAXP2(a,b) (-(-(a)&-(b)))
  41 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  42
  43 struct debug {
  44         int ver;
  45         void *head;
  46         void (*bp)(void);
  47         int state;
  48         void *base;
  49 };
  50
  51 struct dso {
  52         unsigned char *base;
  53         char *name;
  54         size_t *dynv;
  55         struct dso *next, *prev;
  56
  57         Phdr *phdr;
  58         int phnum;
  59         size_t phentsize;
  60         int refcnt;
  61         Sym *syms;
  62         uint32_t *hashtab;
  63         uint32_t *ghashtab;
  64         int16_t *versym;
  65         char *strings;
  66         unsigned char *map;
  67         size_t map_len;
  68         dev_t dev;
  69         ino_t ino;
  70         signed char global;
  71         char relocated;
  72         char constructed;
  73         char kernel_mapped;
  74         struct dso **deps, *needed_by;
  75         char *rpath_orig, *rpath;
  76         void *tls_image;
  77         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  78         size_t relro_start, relro_end;
  79         void **new_dtv;
  80         unsigned char *new_tls;
  81         int new_dtv_idx, new_tls_idx;
  82         struct dso *fini_next;
  83         char *shortname;
  84         char buf[];
  85 };
  86
  87 struct symdef {
  88         Sym *sym;
  89         struct dso *dso;
  90 };
  91
  92 #include "reloc.h"
  93
  94 int __init_tp(void *);
  95 void __init_libc(char **, char *);
  96
  97 const char *__libc_get_version(void);
  98
  99 static struct dso *head, *tail, *ldso, *fini_head;
 100 static char *env_path, *sys_path;
 101 static unsigned long long gencnt;
 102 static int runtime;
 103 static int ldd_mode;
 104 static int ldso_fail;
 105 static int noload;
 106 static jmp_buf *rtld_fail;
 107 static pthread_rwlock_t lock;
 108 static struct debug debug;
 109 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
 110 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 111 static long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)];
 112
 113 struct debug *_dl_debug_addr = &debug;
 114
 115 #define AUX_CNT 38
 116 #define DYN_CNT 34
 117
 118 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 119 {
 120         memset(a, 0, cnt*sizeof(size_t));
 121         for (; v[0]; v+=2) if (v[0]<cnt) {
 122                 a[0] |= 1ULL<<v[0];
 123                 a[v[0]] = v[1];
 124         }
 125 }
 126
 127 static int search_vec(size_t *v, size_t *r, size_t key)
 128 {
 129         for (; v[0]!=key; v+=2)
 130                 if (!v[0]) return 0;
 131         *r = v[1];
 132         return 1;
 133 }
 134
 135 static uint32_t sysv_hash(const char *s0)
 136 {
 137         const unsigned char *s = (void *)s0;
 138         uint_fast32_t h = 0;
 139         while (*s) {
 140                 h = 16*h + *s++;
 141                 h ^= h>>24 & 0xf0;
 142         }
 143         return h & 0xfffffff;
 144 }
 145
 146 static uint32_t gnu_hash(const char *s0)
 147 {
 148         const unsigned char *s = (void *)s0;
 149         uint_fast32_t h = 5381;
 150         for (; *s; s++)
 151                 h = h*33 + *s;
 152         return h;
 153 }
 154
 155 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 156 {
 157         size_t i;
 158         Sym *syms = dso->syms;
 159         uint32_t *hashtab = dso->hashtab;
 160         char *strings = dso->strings;
 161         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 162                 if ((!dso->versym || dso->versym[i] >= 0)
 163                     && (!strcmp(s, strings+syms[i].st_name)))
 164                         return syms+i;
 165         }
 166         return 0;
 167 }
 168
 169 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 170 {
 171         Sym *syms = dso->syms;
 172         char *strings = dso->strings;
 173         uint32_t *hashtab = dso->ghashtab;
 174         uint32_t nbuckets = hashtab[0];
 175         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 176         uint32_t h2;
 177         uint32_t *hashval;
 178         uint32_t i = buckets[h1 % nbuckets];
 179
 180         if (!i) return 0;
 181
 182         hashval = buckets + nbuckets + (i - hashtab[1]);
 183
 184         for (h1 |= 1; ; i++) {
 185                 h2 = *hashval++;
 186                 if ((!dso->versym || dso->versym[i] >= 0)
 187                     && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
 188                         return syms+i;
 189                 if (h2 & 1) break;
 190         }
 191
 192         return 0;
 193 }
 194
 195 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 196 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 197
 198 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 199 {
 200         uint32_t h = 0, gh = 0;
 201         struct symdef def = {0};
 202         for (; dso; dso=dso->next) {
 203                 Sym *sym;
 204                 if (!dso->global) continue;
 205                 if (dso->ghashtab) {
 206                         if (!gh) gh = gnu_hash(s);
 207                         sym = gnu_lookup(s, gh, dso);
 208                 } else {
 209                         if (!h) h = sysv_hash(s);
 210                         sym = sysv_lookup(s, h, dso);
 211                 }
 212                 if (!sym) continue;
 213                 if (!sym->st_shndx)
 214                         if (need_def || (sym->st_info&0xf) == STT_TLS)
 215                                 continue;
 216                 if (!sym->st_value)
 217                         if ((sym->st_info&0xf) != STT_TLS)
 218                                 continue;
 219                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 220                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 221
 222                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 223                 def.sym = sym;
 224                 def.dso = dso;
 225                 if (sym->st_info>>4 == STB_GLOBAL) break;
 226         }
 227         return def;
 228 }
 229
 230 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 231 {
 232         unsigned char *base = dso->base;
 233         Sym *syms = dso->syms;
 234         char *strings = dso->strings;
 235         Sym *sym;
 236         const char *name;
 237         void *ctx;
 238         int type;
 239         int sym_index;
 240         struct symdef def;
 241
 242         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 243                 type = R_TYPE(rel[1]);
 244                 sym_index = R_SYM(rel[1]);
 245                 if (sym_index) {
 246                         sym = syms + sym_index;
 247                         name = strings + sym->st_name;
 248                         ctx = IS_COPY(type) ? head->next : head;
 249                         def = find_sym(ctx, name, IS_PLT(type));
 250                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 251                             || sym->st_info>>4 != STB_WEAK)) {
 252                                 snprintf(errbuf, sizeof errbuf,
 253                                         "Error relocating %s: %s: symbol not found",
 254                                         dso->name, name);
 255                                 if (runtime) longjmp(*rtld_fail, 1);
 256                                 dprintf(2, "%s\n", errbuf);
 257                                 ldso_fail = 1;
 258                                 continue;
 259                         }
 260                 } else {
 261                         sym = 0;
 262                         def.sym = 0;
 263                         def.dso = 0;
 264                 }
 265                 do_single_reloc(dso, base, (void *)(base + rel[0]), type,
 266                         stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def,
 267                         def.sym?(size_t)(def.dso->base+def.sym->st_value):0);
 268         }
 269 }
 270
 271 /* A huge hack: to make up for the wastefulness of shared libraries
 272  * needing at least a page of dirty memory even if they have no global
 273  * data, we reclaim the gaps at the beginning and end of writable maps
 274  * and "donate" them to the heap by setting up minimal malloc
 275  * structures and then freeing them. */
 276
 277 static void reclaim(struct dso *dso, size_t start, size_t end)
 278 {
 279         size_t *a, *z;
 280         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 281         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 282         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 283         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 284         if (start>end || end-start < 4*sizeof(size_t)) return;
 285         a = (size_t *)(dso->base + start);
 286         z = (size_t *)(dso->base + end);
 287         a[-2] = 1;
 288         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 289         z[1] = 1;
 290         free(a);
 291 }
 292
 293 static void reclaim_gaps(struct dso *dso)
 294 {
 295         Phdr *ph = dso->phdr;
 296         size_t phcnt = dso->phnum;
 297
 298         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 299                 if (ph->p_type!=PT_LOAD) continue;
 300                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 301                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 302                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 303                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 304         }
 305 }
 306
 307 static void *map_library(int fd, struct dso *dso)
 308 {
 309         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 310         void *allocated_buf=0;
 311         size_t phsize;
 312         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 313         size_t this_min, this_max;
 314         off_t off_start;
 315         Ehdr *eh;
 316         Phdr *ph, *ph0;
 317         unsigned prot;
 318         unsigned char *map=MAP_FAILED, *base;
 319         size_t dyn=0;
 320         size_t tls_image=0;
 321         size_t i;
 322
 323         ssize_t l = read(fd, buf, sizeof buf);
 324         eh = buf;
 325         if (l<0) return 0;
 326         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 327                 goto noexec;
 328         phsize = eh->e_phentsize * eh->e_phnum;
 329         if (phsize > sizeof buf - sizeof *eh) {
 330                 allocated_buf = malloc(phsize);
 331                 if (!allocated_buf) return 0;
 332                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 333                 if (l < 0) goto error;
 334                 if (l != phsize) goto noexec;
 335                 ph = ph0 = allocated_buf;
 336         } else if (eh->e_phoff + phsize > l) {
 337                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 338                 if (l < 0) goto error;
 339                 if (l != phsize) goto noexec;
 340                 ph = ph0 = (void *)(buf + 1);
 341         } else {
 342                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 343         }
 344         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 345                 if (ph->p_type == PT_DYNAMIC) {
 346                         dyn = ph->p_vaddr;
 347                 } else if (ph->p_type == PT_TLS) {
 348                         tls_image = ph->p_vaddr;
 349                         dso->tls_align = ph->p_align;
 350                         dso->tls_len = ph->p_filesz;
 351                         dso->tls_size = ph->p_memsz;
 352                 } else if (ph->p_type == PT_GNU_RELRO) {
 353                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 354                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 355                 }
 356                 if (ph->p_type != PT_LOAD) continue;
 357                 if (ph->p_vaddr < addr_min) {
 358                         addr_min = ph->p_vaddr;
 359                         off_start = ph->p_offset;
 360                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 361                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 362                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 363                 }
 364                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 365                         addr_max = ph->p_vaddr+ph->p_memsz;
 366                 }
 367         }
 368         if (!dyn) goto noexec;
 369         addr_max += PAGE_SIZE-1;
 370         addr_max &= -PAGE_SIZE;
 371         addr_min &= -PAGE_SIZE;
 372         off_start &= -PAGE_SIZE;
 373         map_len = addr_max - addr_min + off_start;
 374         /* The first time, we map too much, possibly even more than
 375          * the length of the file. This is okay because we will not
 376          * use the invalid part; we just need to reserve the right
 377          * amount of virtual address space to map over later. */
 378         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 379         if (map==MAP_FAILED) goto error;
 380         /* If the loaded file is not relocatable and the requested address is
 381          * not available, then the load operation must fail. */
 382         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 383                 errno = EBUSY;
 384                 goto error;
 385         }
 386         base = map - addr_min;
 387         dso->phdr = 0;
 388         dso->phnum = 0;
 389         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 390                 if (ph->p_type != PT_LOAD) continue;
 391                 /* Check if the programs headers are in this load segment, and
 392                  * if so, record the address for use by dl_iterate_phdr. */
 393                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 394                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 395                         dso->phdr = (void *)(base + ph->p_vaddr
 396                                 + (eh->e_phoff-ph->p_offset));
 397                         dso->phnum = eh->e_phnum;
 398                         dso->phentsize = eh->e_phentsize;
 399                 }
 400                 /* Reuse the existing mapping for the lowest-address LOAD */
 401                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 402                 this_min = ph->p_vaddr & -PAGE_SIZE;
 403                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 404                 off_start = ph->p_offset & -PAGE_SIZE;
 405                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 406                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 407                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 408                 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 409                         goto error;
 410                 if (ph->p_memsz > ph->p_filesz) {
 411                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 412                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 413                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 414                         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)
 415                                 goto error;
 416                 }
 417         }
 418         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 419                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 420                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
 421                                 goto error;
 422                         break;
 423                 }
 424         dso->map = map;
 425         dso->map_len = map_len;
 426         dso->base = base;
 427         dso->dynv = (void *)(base+dyn);
 428         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 429         if (!runtime) reclaim_gaps(dso);
 430         free(allocated_buf);
 431         return map;
 432 noexec:
 433         errno = ENOEXEC;
 434 error:
 435         if (map!=MAP_FAILED) munmap(map, map_len);
 436         free(allocated_buf);
 437         return 0;
 438 }
 439
 440 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 441 {
 442         size_t l;
 443         int fd;
 444         for (;;) {
 445                 s += strspn(s, ":\n");
 446                 l = strcspn(s, ":\n");
 447                 if (l-1 >= INT_MAX) return -1;
 448                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
 449                         continue;
 450                 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 451                 s += l;
 452         }
 453 }
 454
 455 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 456 {
 457         size_t n, l;
 458         const char *s, *t, *origin;
 459         char *d;
 460         if (p->rpath) return 0;
 461         if (!p->rpath_orig) return -1;
 462         if (!strchr(p->rpath_orig, '$')) {
 463                 p->rpath = p->rpath_orig;
 464                 return 0;
 465         }
 466         n = 0;
 467         s = p->rpath_orig;
 468         while ((t=strchr(s, '$'))) {
 469                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 470                         return -1;
 471                 s = t+1;
 472                 n++;
 473         }
 474         if (n > SSIZE_MAX/PATH_MAX) return -1;
 475
 476         if (p->kernel_mapped) {
 477                 /* $ORIGIN searches cannot be performed for the main program
 478                  * when it is suid/sgid/AT_SECURE. This is because the
 479                  * pathname is under the control of the caller of execve.
 480                  * For libraries, however, $ORIGIN can be processed safely
 481                  * since the library's pathname came from a trusted source
 482                  * (either system paths or a call to dlopen). */
 483                 if (libc.secure)
 484                         return -1;
 485                 l = readlink("/proc/self/exe", buf, buf_size);
 486                 if (l >= buf_size)
 487                         return -1;
 488                 buf[l] = 0;
 489                 origin = buf;
 490         } else {
 491                 origin = p->name;
 492         }
 493         t = strrchr(origin, '/');
 494         l = t ? t-origin : 0;
 495         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 496         if (!p->rpath) return -1;
 497
 498         d = p->rpath;
 499         s = p->rpath_orig;
 500         while ((t=strchr(s, '$'))) {
 501                 memcpy(d, s, t-s);
 502                 d += t-s;
 503                 memcpy(d, origin, l);
 504                 d += l;
 505                 /* It was determined previously that the '$' is followed
 506                  * either by "ORIGIN" or "{ORIGIN}". */
 507                 s = t + 7 + 2*(t[1]=='{');
 508         }
 509         strcpy(d, s);
 510         return 0;
 511 }
 512
 513 static void decode_dyn(struct dso *p)
 514 {
 515         size_t dyn[DYN_CNT] = {0};
 516         decode_vec(p->dynv, dyn, DYN_CNT);
 517         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 518         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 519         if (dyn[0]&(1<<DT_HASH))
 520                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 521         if (dyn[0]&(1<<DT_RPATH))
 522                 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
 523         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 524                 p->ghashtab = (void *)(p->base + *dyn);
 525         if (search_vec(p->dynv, dyn, DT_VERSYM))
 526                 p->versym = (void *)(p->base + *dyn);
 527 }
 528
 529 static struct dso *load_library(const char *name, struct dso *needed_by)
 530 {
 531         char buf[2*NAME_MAX+2];
 532         const char *pathname;
 533         unsigned char *map;
 534         struct dso *p, temp_dso = {0};
 535         int fd;
 536         struct stat st;
 537         size_t alloc_size;
 538         int n_th = 0;
 539         int is_self = 0;
 540
 541         /* Catch and block attempts to reload the implementation itself */
 542         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 543                 static const char *rp, reserved[] =
 544                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 545                 char *z = strchr(name, '.');
 546                 if (z) {
 547                         size_t l = z-name;
 548                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 549                         if (*rp) {
 550                                 if (ldd_mode) {
 551                                         /* Track which names have been resolved
 552                                          * and only report each one once. */
 553                                         static unsigned reported;
 554                                         unsigned mask = 1U<<(rp-reserved);
 555                                         if (!(reported & mask)) {
 556                                                 reported |= mask;
 557                                                 dprintf(1, "\t%s => %s (%p)\n",
 558                                                         name, ldso->name,
 559                                                         ldso->base);
 560                                         }
 561                                 }
 562                                 is_self = 1;
 563                         }
 564                 }
 565         }
 566         if (!strcmp(name, ldso->name)) is_self = 1;
 567         if (is_self) {
 568                 if (!ldso->prev) {
 569                         tail->next = ldso;
 570                         ldso->prev = tail;
 571                         tail = ldso->next ? ldso->next : ldso;
 572                 }
 573                 return ldso;
 574         }
 575         if (strchr(name, '/')) {
 576                 pathname = name;
 577                 fd = open(name, O_RDONLY|O_CLOEXEC);
 578         } else {
 579                 /* Search for the name to see if it's already loaded */
 580                 for (p=head->next; p; p=p->next) {
 581                         if (p->shortname && !strcmp(p->shortname, name)) {
 582                                 p->refcnt++;
 583                                 return p;
 584                         }
 585                 }
 586                 if (strlen(name) > NAME_MAX) return 0;
 587                 fd = -1;
 588                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 589                 for (p=needed_by; fd < 0 && p; p=p->needed_by)
 590                         if (!fixup_rpath(p, buf, sizeof buf))
 591                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 592                 if (fd < 0) {
 593                         if (!sys_path) {
 594                                 char *prefix = 0;
 595                                 size_t prefix_len;
 596                                 if (ldso->name[0]=='/') {
 597                                         char *s, *t, *z;
 598                                         for (s=t=z=ldso->name; *s; s++)
 599                                                 if (*s=='/') z=t, t=s;
 600                                         prefix_len = z-ldso->name;
 601                                         if (prefix_len < PATH_MAX)
 602                                                 prefix = ldso->name;
 603                                 }
 604                                 if (!prefix) {
 605                                         prefix = "";
 606                                         prefix_len = 0;
 607                                 }
 608                                 char etc_ldso_path[prefix_len + 1
 609                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 610                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 611                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 612                                         (int)prefix_len, prefix);
 613                                 FILE *f = fopen(etc_ldso_path, "rbe");
 614                                 if (f) {
 615                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 616                                                 free(sys_path);
 617                                                 sys_path = "";
 618                                         }
 619                                         fclose(f);
 620                                 } else if (errno != ENOENT) {
 621                                         sys_path = "";
 622                                 }
 623                         }
 624                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 625                         fd = path_open(name, sys_path, buf, sizeof buf);
 626                 }
 627                 pathname = buf;
 628         }
 629         if (fd < 0) return 0;
 630         if (fstat(fd, &st) < 0) {
 631                 close(fd);
 632                 return 0;
 633         }
 634         for (p=head->next; p; p=p->next) {
 635                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 636                         /* If this library was previously loaded with a
 637                          * pathname but a search found the same inode,
 638                          * setup its shortname so it can be found by name. */
 639                         if (!p->shortname && pathname != name)
 640                                 p->shortname = strrchr(p->name, '/')+1;
 641                         close(fd);
 642                         p->refcnt++;
 643                         return p;
 644                 }
 645         }
 646         map = noload ? 0 : map_library(fd, &temp_dso);
 647         close(fd);
 648         if (!map) return 0;
 649
 650         /* Allocate storage for the new DSO. When there is TLS, this
 651          * storage must include a reservation for all pre-existing
 652          * threads to obtain copies of both the new TLS, and an
 653          * extended DTV capable of storing an additional slot for
 654          * the newly-loaded DSO. */
 655         alloc_size = sizeof *p + strlen(pathname) + 1;
 656         if (runtime && temp_dso.tls_image) {
 657                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 658                         + sizeof(void *) * (tls_cnt+3);
 659                 n_th = libc.threads_minus_1 + 1;
 660                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 661                 else alloc_size += n_th * per_th;
 662         }
 663         p = calloc(1, alloc_size);
 664         if (!p) {
 665                 munmap(map, temp_dso.map_len);
 666                 return 0;
 667         }
 668         memcpy(p, &temp_dso, sizeof temp_dso);
 669         decode_dyn(p);
 670         p->dev = st.st_dev;
 671         p->ino = st.st_ino;
 672         p->refcnt = 1;
 673         p->needed_by = needed_by;
 674         p->name = p->buf;
 675         strcpy(p->name, pathname);
 676         /* Add a shortname only if name arg was not an explicit pathname. */
 677         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 678         if (p->tls_image) {
 679                 if (runtime && !libc.has_thread_pointer) {
 680                         munmap(map, p->map_len);
 681                         free(p);
 682                         errno = ENOSYS;
 683                         return 0;
 684                 }
 685                 p->tls_id = ++tls_cnt;
 686                 tls_align = MAXP2(tls_align, p->tls_align);
 687 #ifdef TLS_ABOVE_TP
 688                 p->tls_offset = tls_offset + ( (tls_align-1) &
 689                         -(tls_offset + (uintptr_t)p->tls_image) );
 690                 tls_offset += p->tls_size;
 691 #else
 692                 tls_offset += p->tls_size + p->tls_align - 1;
 693                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 694                         & (p->tls_align-1);
 695                 p->tls_offset = tls_offset;
 696 #endif
 697                 p->new_dtv = (void *)(-sizeof(size_t) &
 698                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 699                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 700         }
 701
 702         tail->next = p;
 703         p->prev = tail;
 704         tail = p;
 705
 706         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 707
 708         return p;
 709 }
 710
 711 static void load_deps(struct dso *p)
 712 {
 713         size_t i, ndeps=0;
 714         struct dso ***deps = &p->deps, **tmp, *dep;
 715         for (; p; p=p->next) {
 716                 for (i=0; p->dynv[i]; i+=2) {
 717                         if (p->dynv[i] != DT_NEEDED) continue;
 718                         dep = load_library(p->strings + p->dynv[i+1], p);
 719                         if (!dep) {
 720                                 snprintf(errbuf, sizeof errbuf,
 721                                         "Error loading shared library %s: %m (needed by %s)",
 722                                         p->strings + p->dynv[i+1], p->name);
 723                                 if (runtime) longjmp(*rtld_fail, 1);
 724                                 dprintf(2, "%s\n", errbuf);
 725                                 ldso_fail = 1;
 726                                 continue;
 727                         }
 728                         if (runtime) {
 729                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 730                                 if (!tmp) longjmp(*rtld_fail, 1);
 731                                 tmp[ndeps++] = dep;
 732                                 tmp[ndeps] = 0;
 733                                 *deps = tmp;
 734                         }
 735                 }
 736         }
 737 }
 738
 739 static void load_preload(char *s)
 740 {
 741         int tmp;
 742         char *z;
 743         for (z=s; *z; s=z) {
 744                 for (   ; *s && isspace(*s); s++);
 745                 for (z=s; *z && !isspace(*z); z++);
 746                 tmp = *z;
 747                 *z = 0;
 748                 load_library(s, 0);
 749                 *z = tmp;
 750         }
 751 }
 752
 753 static void make_global(struct dso *p)
 754 {
 755         for (; p; p=p->next) p->global = 1;
 756 }
 757
 758 static void reloc_all(struct dso *p)
 759 {
 760         size_t dyn[DYN_CNT] = {0};
 761         for (; p; p=p->next) {
 762                 if (p->relocated) continue;
 763                 decode_vec(p->dynv, dyn, DYN_CNT);
 764 #ifdef NEED_ARCH_RELOCS
 765                 do_arch_relocs(p, head);
 766 #endif
 767                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 768                         2+(dyn[DT_PLTREL]==DT_RELA));
 769                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 770                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 771
 772                 if (p->relro_start != p->relro_end &&
 773                     mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
 774                         snprintf(errbuf, sizeof errbuf,
 775                                 "Error relocating %s: RELRO protection failed: %m",
 776                                 p->name);
 777                         if (runtime) longjmp(*rtld_fail, 1);
 778                         dprintf(2, "%s\n", errbuf);
 779                         ldso_fail = 1;
 780                 }
 781
 782                 p->relocated = 1;
 783         }
 784 }
 785
 786 static void kernel_mapped_dso(struct dso *p)
 787 {
 788         size_t min_addr = -1, max_addr = 0, cnt;
 789         Phdr *ph = p->phdr;
 790         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
 791                 if (ph->p_type == PT_DYNAMIC) {
 792                         p->dynv = (void *)(p->base + ph->p_vaddr);
 793                 } else if (ph->p_type == PT_GNU_RELRO) {
 794                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
 795                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 796                 }
 797                 if (ph->p_type != PT_LOAD) continue;
 798                 if (ph->p_vaddr < min_addr)
 799                         min_addr = ph->p_vaddr;
 800                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 801                         max_addr = ph->p_vaddr+ph->p_memsz;
 802         }
 803         min_addr &= -PAGE_SIZE;
 804         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 805         p->map = p->base + min_addr;
 806         p->map_len = max_addr - min_addr;
 807         p->kernel_mapped = 1;
 808 }
 809
 810 static void do_fini()
 811 {
 812         struct dso *p;
 813         size_t dyn[DYN_CNT] = {0};
 814         for (p=fini_head; p; p=p->fini_next) {
 815                 if (!p->constructed) continue;
 816                 decode_vec(p->dynv, dyn, DYN_CNT);
 817                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
 818                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
 819                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
 820                         while (n--) ((void (*)(void))*--fn)();
 821                 }
 822 #ifndef NO_LEGACY_INITFINI
 823                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 824                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
 825 #endif
 826         }
 827 }
 828
 829 static void do_init_fini(struct dso *p)
 830 {
 831         size_t dyn[DYN_CNT] = {0};
 832         int need_locking = libc.threads_minus_1;
 833         /* Allow recursive calls that arise when a library calls
 834          * dlopen from one of its constructors, but block any
 835          * other threads until all ctors have finished. */
 836         if (need_locking) pthread_mutex_lock(&init_fini_lock);
 837         for (; p; p=p->prev) {
 838                 if (p->constructed) continue;
 839                 p->constructed = 1;
 840                 decode_vec(p->dynv, dyn, DYN_CNT);
 841                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
 842                         p->fini_next = fini_head;
 843                         fini_head = p;
 844                 }
 845 #ifndef NO_LEGACY_INITFINI
 846                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 847                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
 848 #endif
 849                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
 850                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
 851                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
 852                         while (n--) ((void (*)(void))*fn++)();
 853                 }
 854                 if (!need_locking && libc.threads_minus_1) {
 855                         need_locking = 1;
 856                         pthread_mutex_lock(&init_fini_lock);
 857                 }
 858         }
 859         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 860 }
 861
 862 void _dl_debug_state(void)
 863 {
 864 }
 865
 866 void __reset_tls()
 867 {
 868         pthread_t self = __pthread_self();
 869         struct dso *p;
 870         for (p=head; p; p=p->next) {
 871                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
 872                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
 873                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
 874                         p->tls_size - p->tls_len);
 875                 if (p->tls_id == (size_t)self->dtv[0]) break;
 876         }
 877 }
 878
 879 void *__copy_tls(unsigned char *mem)
 880 {
 881         pthread_t td;
 882         struct dso *p;
 883
 884         void **dtv = (void *)mem;
 885         dtv[0] = (void *)tls_cnt;
 886         if (!tls_cnt) {
 887                 td = (void *)(dtv+1);
 888                 td->dtv = dtv;
 889                 return td;
 890         }
 891
 892 #ifdef TLS_ABOVE_TP
 893         mem += sizeof(void *) * (tls_cnt+1);
 894         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
 895         td = (pthread_t)mem;
 896         mem += sizeof(struct pthread);
 897
 898         for (p=head; p; p=p->next) {
 899                 if (!p->tls_id) continue;
 900                 dtv[p->tls_id] = mem + p->tls_offset;
 901                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 902         }
 903 #else
 904         mem += libc.tls_size - sizeof(struct pthread);
 905         mem -= (uintptr_t)mem & (tls_align-1);
 906         td = (pthread_t)mem;
 907
 908         for (p=head; p; p=p->next) {
 909                 if (!p->tls_id) continue;
 910                 dtv[p->tls_id] = mem - p->tls_offset;
 911                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 912         }
 913 #endif
 914         td->dtv = dtv;
 915         return td;
 916 }
 917
 918 void *__tls_get_addr(size_t *v)
 919 {
 920         pthread_t self = __pthread_self();
 921         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
 922                 return (char *)self->dtv[v[0]]+v[1];
 923
 924         /* Block signals to make accessing new TLS async-signal-safe */
 925         sigset_t set;
 926         pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
 927         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
 928                 pthread_sigmask(SIG_SETMASK, &set, 0);
 929                 return (char *)self->dtv[v[0]]+v[1];
 930         }
 931
 932         /* This is safe without any locks held because, if the caller
 933          * is able to request the Nth entry of the DTV, the DSO list
 934          * must be valid at least that far out and it was synchronized
 935          * at program startup or by an already-completed call to dlopen. */
 936         struct dso *p;
 937         for (p=head; p->tls_id != v[0]; p=p->next);
 938
 939         /* Get new DTV space from new DSO if needed */
 940         if (v[0] > (size_t)self->dtv[0]) {
 941                 void **newdtv = p->new_dtv +
 942                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
 943                 memcpy(newdtv, self->dtv,
 944                         ((size_t)self->dtv[0]+1) * sizeof(void *));
 945                 newdtv[0] = (void *)v[0];
 946                 self->dtv = newdtv;
 947         }
 948
 949         /* Get new TLS memory from new DSO */
 950         unsigned char *mem = p->new_tls +
 951                 (p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1);
 952         mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1);
 953         self->dtv[v[0]] = mem;
 954         memcpy(mem, p->tls_image, p->tls_len);
 955         pthread_sigmask(SIG_SETMASK, &set, 0);
 956         return mem + v[1];
 957 }
 958
 959 static void update_tls_size()
 960 {
 961         libc.tls_size = ALIGN(
 962                 (1+tls_cnt) * sizeof(void *) +
 963                 tls_offset +
 964                 sizeof(struct pthread) +
 965                 tls_align * 2,
 966         tls_align);
 967 }
 968
 969 void *__dynlink(int argc, char **argv)
 970 {
 971         size_t aux[AUX_CNT] = {0};
 972         size_t i;
 973         Phdr *phdr;
 974         Ehdr *ehdr;
 975         static struct dso builtin_dsos[3];
 976         struct dso *const app = builtin_dsos+0;
 977         struct dso *const lib = builtin_dsos+1;
 978         struct dso *const vdso = builtin_dsos+2;
 979         char *env_preload=0;
 980         size_t vdso_base;
 981         size_t *auxv;
 982         char **envp = argv+argc+1;
 983         void *initial_tls;
 984
 985         /* Find aux vector just past environ[] */
 986         for (i=argc+1; argv[i]; i++)
 987                 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
 988                         env_path = argv[i]+16;
 989                 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
 990                         env_preload = argv[i]+11;
 991         auxv = (void *)(argv+i+1);
 992
 993         decode_vec(auxv, aux, AUX_CNT);
 994
 995         /* Only trust user/env if kernel says we're not suid/sgid */
 996         if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
 997           || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
 998                 env_path = 0;
 999                 env_preload = 0;
1000                 libc.secure = 1;
1001         }
1002         libc.page_size = aux[AT_PAGESZ];
1003
1004         /* If the dynamic linker was invoked as a program itself, AT_BASE
1005          * will not be set. In that case, we assume the base address is
1006          * the start of the page containing the PHDRs; I don't know any
1007          * better approach... */
1008         if (!aux[AT_BASE]) {
1009                 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
1010                 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
1011         }
1012
1013         /* The dynamic linker load address is passed by the kernel
1014          * in the AUX vector, so this is easy. */
1015         lib->base = (void *)aux[AT_BASE];
1016         lib->name = lib->shortname = "libc.so";
1017         lib->global = 1;
1018         ehdr = (void *)lib->base;
1019         lib->phnum = ehdr->e_phnum;
1020         lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
1021         lib->phentsize = ehdr->e_phentsize;
1022         kernel_mapped_dso(lib);
1023         decode_dyn(lib);
1024
1025         if (aux[AT_PHDR]) {
1026                 size_t interp_off = 0;
1027                 size_t tls_image = 0;
1028                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1029                 app->phdr = phdr = (void *)aux[AT_PHDR];
1030                 app->phnum = aux[AT_PHNUM];
1031                 app->phentsize = aux[AT_PHENT];
1032                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1033                         if (phdr->p_type == PT_PHDR)
1034                                 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1035                         else if (phdr->p_type == PT_INTERP)
1036                                 interp_off = (size_t)phdr->p_vaddr;
1037                         else if (phdr->p_type == PT_TLS) {
1038                                 tls_image = phdr->p_vaddr;
1039                                 app->tls_len = phdr->p_filesz;
1040                                 app->tls_size = phdr->p_memsz;
1041                                 app->tls_align = phdr->p_align;
1042                         }
1043                 }
1044                 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
1045                 if (interp_off) lib->name = (char *)app->base + interp_off;
1046                 if ((aux[0] & (1UL<<AT_EXECFN))
1047                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1048                         app->name = (char *)aux[AT_EXECFN];
1049                 else
1050                         app->name = argv[0];
1051                 kernel_mapped_dso(app);
1052         } else {
1053                 int fd;
1054                 char *ldname = argv[0];
1055                 size_t l = strlen(ldname);
1056                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1057                 *argv++ = (void *)-1;
1058                 if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
1059                 if (!argv[0]) {
1060                         dprintf(2, "musl libc\n"
1061                                 "Version %s\n"
1062                                 "Dynamic Program Loader\n"
1063                                 "Usage: %s [--] pathname%s\n",
1064                                 __libc_get_version(), ldname,
1065                                 ldd_mode ? "" : " [args]");
1066                         _exit(1);
1067                 }
1068                 fd = open(argv[0], O_RDONLY);
1069                 if (fd < 0) {
1070                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1071                         _exit(1);
1072                 }
1073                 runtime = 1;
1074                 ehdr = (void *)map_library(fd, app);
1075                 if (!ehdr) {
1076                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1077                         _exit(1);
1078                 }
1079                 runtime = 0;
1080                 close(fd);
1081                 lib->name = ldname;
1082                 app->name = argv[0];
1083                 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
1084                 /* Find the name that would have been used for the dynamic
1085                  * linker had ldd not taken its place. */
1086                 if (ldd_mode) {
1087                         for (i=0; i<app->phnum; i++) {
1088                                 if (app->phdr[i].p_type == PT_INTERP)
1089                                         lib->name = (void *)(app->base
1090                                                 + app->phdr[i].p_vaddr);
1091                         }
1092                         dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
1093                 }
1094         }
1095         if (app->tls_size) {
1096                 app->tls_id = tls_cnt = 1;
1097 #ifdef TLS_ABOVE_TP
1098                 app->tls_offset = 0;
1099                 tls_offset = app->tls_size
1100                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1101                         & (app->tls_align-1) );
1102 #else
1103                 tls_offset = app->tls_offset = app->tls_size
1104                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1105                         & (app->tls_align-1) );
1106 #endif
1107                 tls_align = MAXP2(tls_align, app->tls_align);
1108         }
1109         app->global = 1;
1110         decode_dyn(app);
1111
1112         /* Attach to vdso, if provided by the kernel */
1113         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1114                 ehdr = (void *)vdso_base;
1115                 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1116                 vdso->phnum = ehdr->e_phnum;
1117                 vdso->phentsize = ehdr->e_phentsize;
1118                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1119                         if (phdr->p_type == PT_DYNAMIC)
1120                                 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1121                         if (phdr->p_type == PT_LOAD)
1122                                 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1123                 }
1124                 vdso->name = "";
1125                 vdso->shortname = "linux-gate.so.1";
1126                 vdso->global = 1;
1127                 decode_dyn(vdso);
1128                 vdso->prev = lib;
1129                 lib->next = vdso;
1130         }
1131
1132         /* Initial dso chain consists only of the app. We temporarily
1133          * append the dynamic linker/libc so we can relocate it, then
1134          * restore the initial chain in preparation for loading third
1135          * party libraries (preload/needed). */
1136         head = tail = app;
1137         ldso = lib;
1138         app->next = lib;
1139         reloc_all(lib);
1140         app->next = 0;
1141
1142         /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1143
1144         /* Donate unused parts of app and library mapping to malloc */
1145         reclaim_gaps(app);
1146         reclaim_gaps(lib);
1147
1148         /* Load preload/needed libraries, add their symbols to the global
1149          * namespace, and perform all remaining relocations. The main
1150          * program must be relocated LAST since it may contain copy
1151          * relocations which depend on libraries' relocations. */
1152         if (env_preload) load_preload(env_preload);
1153         load_deps(app);
1154         make_global(app);
1155
1156 #ifndef DYNAMIC_IS_RO
1157         for (i=0; app->dynv[i]; i+=2)
1158                 if (app->dynv[i]==DT_DEBUG)
1159                         app->dynv[i+1] = (size_t)&debug;
1160 #endif
1161
1162         reloc_all(app->next);
1163         reloc_all(app);
1164
1165         update_tls_size();
1166         if (libc.tls_size > sizeof builtin_tls) {
1167                 initial_tls = calloc(libc.tls_size, 1);
1168                 if (!initial_tls) {
1169                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1170                                 argv[0], libc.tls_size);
1171                         _exit(127);
1172                 }
1173         } else {
1174                 initial_tls = builtin_tls;
1175         }
1176         if (__init_tp(__copy_tls(initial_tls)) < 0 && tls_cnt) {
1177                 dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]);
1178                 _exit(127);
1179         }
1180
1181         if (ldso_fail) _exit(127);
1182         if (ldd_mode) _exit(0);
1183
1184         /* Switch to runtime mode: any further failures in the dynamic
1185          * linker are a reportable failure rather than a fatal startup
1186          * error. If the dynamic loader (dlopen) will not be used, free
1187          * all memory used by the dynamic linker. */
1188         runtime = 1;
1189
1190         debug.ver = 1;
1191         debug.bp = _dl_debug_state;
1192         debug.head = head;
1193         debug.base = lib->base;
1194         debug.state = 0;
1195         _dl_debug_state();
1196
1197         __init_libc(envp, argv[0]);
1198         atexit(do_fini);
1199         errno = 0;
1200         do_init_fini(tail);
1201
1202         return (void *)aux[AT_ENTRY];
1203 }
1204
1205 void *dlopen(const char *file, int mode)
1206 {
1207         struct dso *volatile p, *orig_tail, *next;
1208         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1209         size_t i;
1210         int cs;
1211         jmp_buf jb;
1212
1213         if (!file) return head;
1214
1215         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1216         pthread_rwlock_wrlock(&lock);
1217         __inhibit_ptc();
1218
1219         p = 0;
1220         orig_tls_cnt = tls_cnt;
1221         orig_tls_offset = tls_offset;
1222         orig_tls_align = tls_align;
1223         orig_tail = tail;
1224         noload = mode & RTLD_NOLOAD;
1225
1226         rtld_fail = &jb;
1227         if (setjmp(*rtld_fail)) {
1228                 /* Clean up anything new that was (partially) loaded */
1229                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1230                         if (p->deps[i]->global < 0)
1231                                 p->deps[i]->global = 0;
1232                 for (p=orig_tail->next; p; p=next) {
1233                         next = p->next;
1234                         munmap(p->map, p->map_len);
1235                         free(p->deps);
1236                         free(p);
1237                 }
1238                 tls_cnt = orig_tls_cnt;
1239                 tls_offset = orig_tls_offset;
1240                 tls_align = orig_tls_align;
1241                 tail = orig_tail;
1242                 tail->next = 0;
1243                 p = 0;
1244                 errflag = 1;
1245                 goto end;
1246         } else p = load_library(file, head);
1247
1248         if (!p) {
1249                 snprintf(errbuf, sizeof errbuf, noload ?
1250                         "Library %s is not already loaded" :
1251                         "Error loading shared library %s: %m",
1252                         file);
1253                 errflag = 1;
1254                 goto end;
1255         }
1256
1257         /* First load handling */
1258         if (!p->deps) {
1259                 load_deps(p);
1260                 if (p->deps) for (i=0; p->deps[i]; i++)
1261                         if (!p->deps[i]->global)
1262                                 p->deps[i]->global = -1;
1263                 if (!p->global) p->global = -1;
1264                 reloc_all(p);
1265                 if (p->deps) for (i=0; p->deps[i]; i++)
1266                         if (p->deps[i]->global < 0)
1267                                 p->deps[i]->global = 0;
1268                 if (p->global < 0) p->global = 0;
1269         }
1270
1271         if (mode & RTLD_GLOBAL) {
1272                 if (p->deps) for (i=0; p->deps[i]; i++)
1273                         p->deps[i]->global = 1;
1274                 p->global = 1;
1275         }
1276
1277         update_tls_size();
1278         _dl_debug_state();
1279         orig_tail = tail;
1280 end:
1281         __release_ptc();
1282         if (p) gencnt++;
1283         pthread_rwlock_unlock(&lock);
1284         if (p) do_init_fini(orig_tail);
1285         pthread_setcancelstate(cs, 0);
1286         return p;
1287 }
1288
1289 static int invalid_dso_handle(void *h)
1290 {
1291         struct dso *p;
1292         for (p=head; p; p=p->next) if (h==p) return 0;
1293         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1294         errflag = 1;
1295         return 1;
1296 }
1297
1298 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1299 {
1300         size_t i;
1301         uint32_t h = 0, gh = 0;
1302         Sym *sym;
1303         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1304                 if (p == RTLD_DEFAULT) {
1305                         p = head;
1306                 } else if (p == RTLD_NEXT) {
1307                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1308                         if (!p) p=head;
1309                         p = p->next;
1310                 }
1311                 struct symdef def = find_sym(p, s, 0);
1312                 if (!def.sym) goto failed;
1313                 if ((def.sym->st_info&0xf) == STT_TLS)
1314                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1315                 return def.dso->base + def.sym->st_value;
1316         }
1317         if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1318                 return 0;
1319         if (p->ghashtab) {
1320                 gh = gnu_hash(s);
1321                 sym = gnu_lookup(s, gh, p);
1322         } else {
1323                 h = sysv_hash(s);
1324                 sym = sysv_lookup(s, h, p);
1325         }
1326         if (sym && (sym->st_info&0xf) == STT_TLS)
1327                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1328         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1329                 return p->base + sym->st_value;
1330         if (p->deps) for (i=0; p->deps[i]; i++) {
1331                 if (p->deps[i]->ghashtab) {
1332                         if (!gh) gh = gnu_hash(s);
1333                         sym = gnu_lookup(s, gh, p->deps[i]);
1334                 } else {
1335                         if (!h) h = sysv_hash(s);
1336                         sym = sysv_lookup(s, h, p->deps[i]);
1337                 }
1338                 if (sym && (sym->st_info&0xf) == STT_TLS)
1339                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1340                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1341                         return p->deps[i]->base + sym->st_value;
1342         }
1343 failed:
1344         errflag = 1;
1345         snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1346         return 0;
1347 }
1348
1349 int __dladdr(const void *addr, Dl_info *info)
1350 {
1351         struct dso *p;
1352         Sym *sym;
1353         uint32_t nsym;
1354         char *strings;
1355         size_t i;
1356         void *best = 0;
1357         char *bestname;
1358
1359         pthread_rwlock_rdlock(&lock);
1360         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1361         pthread_rwlock_unlock(&lock);
1362
1363         if (!p) return 0;
1364
1365         sym = p->syms;
1366         strings = p->strings;
1367         if (p->hashtab) {
1368                 nsym = p->hashtab[1];
1369         } else {
1370                 uint32_t *buckets;
1371                 uint32_t *hashval;
1372                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1373                 sym += p->ghashtab[1];
1374                 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1375                         if (buckets[i] > nsym)
1376                                 nsym = buckets[i];
1377                 }
1378                 if (nsym) {
1379                         nsym -= p->ghashtab[1];
1380                         hashval = buckets + p->ghashtab[0] + nsym;
1381                         do nsym++;
1382                         while (!(*hashval++ & 1));
1383                 }
1384         }
1385
1386         for (; nsym; nsym--, sym++) {
1387                 if (sym->st_value
1388                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1389                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1390                         void *symaddr = p->base + sym->st_value;
1391                         if (symaddr > addr || symaddr < best)
1392                                 continue;
1393                         best = symaddr;
1394                         bestname = strings + sym->st_name;
1395                         if (addr == symaddr)
1396                                 break;
1397                 }
1398         }
1399
1400         if (!best) return 0;
1401
1402         info->dli_fname = p->name;
1403         info->dli_fbase = p->base;
1404         info->dli_sname = bestname;
1405         info->dli_saddr = best;
1406
1407         return 1;
1408 }
1409
1410 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1411 {
1412         void *res;
1413         pthread_rwlock_rdlock(&lock);
1414         res = do_dlsym(p, s, ra);
1415         pthread_rwlock_unlock(&lock);
1416         return res;
1417 }
1418
1419 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1420 {
1421         struct dso *current;
1422         struct dl_phdr_info info;
1423         int ret = 0;
1424         for(current = head; current;) {
1425                 info.dlpi_addr      = (uintptr_t)current->base;
1426                 info.dlpi_name      = current->name;
1427                 info.dlpi_phdr      = current->phdr;
1428                 info.dlpi_phnum     = current->phnum;
1429                 info.dlpi_adds      = gencnt;
1430                 info.dlpi_subs      = 0;
1431                 info.dlpi_tls_modid = current->tls_id;
1432                 info.dlpi_tls_data  = current->tls_image;
1433
1434                 ret = (callback)(&info, sizeof (info), data);
1435
1436                 if (ret != 0) break;
1437
1438                 pthread_rwlock_rdlock(&lock);
1439                 current = current->next;
1440                 pthread_rwlock_unlock(&lock);
1441         }
1442         return ret;
1443 }
1444 #else
1445 static int invalid_dso_handle(void *h)
1446 {
1447         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1448         errflag = 1;
1449         return 1;
1450 }
1451 void *dlopen(const char *file, int mode)
1452 {
1453         return 0;
1454 }
1455 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1456 {
1457         return 0;
1458 }
1459 int __dladdr (const void *addr, Dl_info *info)
1460 {
1461         return 0;
1462 }
1463 #endif
1464
1465 int __dlinfo(void *dso, int req, void *res)
1466 {
1467         if (invalid_dso_handle(dso)) return -1;
1468         if (req != RTLD_DI_LINKMAP) {
1469                 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1470                 errflag = 1;
1471                 return -1;
1472         }
1473         *(struct link_map **)res = dso;
1474         return 0;
1475 }
1476
1477 char *dlerror()
1478 {
1479         if (!errflag) return 0;
1480         errflag = 0;
1481         return errbuf;
1482 }
1483
1484 int dlclose(void *p)
1485 {
1486         return invalid_dso_handle(p);
1487 }