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 <stdint.h>
  11 #include <fcntl.h>
  12 #include <sys/stat.h>
  13 #include <errno.h>
  14 #include <limits.h>
  15 #include <elf.h>
  16 #include <link.h>
  17 #include <setjmp.h>
  18 #include <pthread.h>
  19 #include <ctype.h>
  20 #include <dlfcn.h>
  21 #include "pthread_impl.h"
  22 #include "libc.h"
  23
  24 static int errflag;
  25 static char errbuf[128];
  26
  27 #ifdef SHARED
  28
  29 #if ULONG_MAX == 0xffffffff
  30 typedef Elf32_Ehdr Ehdr;
  31 typedef Elf32_Phdr Phdr;
  32 typedef Elf32_Sym Sym;
  33 #define R_TYPE(x) ((x)&255)
  34 #define R_SYM(x) ((x)>>8)
  35 #else
  36 typedef Elf64_Ehdr Ehdr;
  37 typedef Elf64_Phdr Phdr;
  38 typedef Elf64_Sym Sym;
  39 #define R_TYPE(x) ((x)&0xffffffff)
  40 #define R_SYM(x) ((x)>>32)
  41 #endif
  42
  43 #define MAXP2(a,b) (-(-(a)&-(b)))
  44 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  45
  46 struct debug {
  47         int ver;
  48         void *head;
  49         void (*bp)(void);
  50         int state;
  51         void *base;
  52 };
  53
  54 struct dso {
  55         unsigned char *base;
  56         char *name;
  57         size_t *dynv;
  58         struct dso *next, *prev;
  59
  60         Phdr *phdr;
  61         int phnum;
  62         int refcnt;
  63         Sym *syms;
  64         uint32_t *hashtab;
  65         uint32_t *ghashtab;
  66         char *strings;
  67         unsigned char *map;
  68         size_t map_len;
  69         dev_t dev;
  70         ino_t ino;
  71         signed char global;
  72         char relocated;
  73         char constructed;
  74         struct dso **deps;
  75         void *tls_image;
  76         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  77         void **new_dtv;
  78         unsigned char *new_tls;
  79         int new_dtv_idx, new_tls_idx;
  80         struct dso *fini_next;
  81         char *shortname;
  82         char buf[];
  83 };
  84
  85 struct symdef {
  86         Sym *sym;
  87         struct dso *dso;
  88 };
  89
  90 #include "reloc.h"
  91
  92 void __init_ssp(size_t *);
  93 void *__install_initial_tls(void *);
  94 void __init_libc(char **, char *);
  95
  96 static struct dso *head, *tail, *ldso, *fini_head;
  97 static char *env_path, *sys_path, *r_path;
  98 static unsigned long long gencnt;
  99 static int ssp_used;
 100 static int runtime;
 101 static int ldd_mode;
 102 static int ldso_fail;
 103 static int noload;
 104 static jmp_buf *rtld_fail;
 105 static pthread_rwlock_t lock;
 106 static struct debug debug;
 107 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
 108 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 109
 110 struct debug *_dl_debug_addr = &debug;
 111
 112 #define AUX_CNT 38
 113 #define DYN_CNT 34
 114
 115 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 116 {
 117         memset(a, 0, cnt*sizeof(size_t));
 118         for (; v[0]; v+=2) if (v[0]<cnt) {
 119                 a[0] |= 1ULL<<v[0];
 120                 a[v[0]] = v[1];
 121         }
 122 }
 123
 124 static int search_vec(size_t *v, size_t *r, size_t key)
 125 {
 126         for (; v[0]!=key; v+=2)
 127                 if (!v[0]) return 0;
 128         *r = v[1];
 129         return 1;
 130 }
 131
 132 static uint32_t sysv_hash(const char *s0)
 133 {
 134         const unsigned char *s = (void *)s0;
 135         uint_fast32_t h = 0;
 136         while (*s) {
 137                 h = 16*h + *s++;
 138                 h ^= h>>24 & 0xf0;
 139         }
 140         return h & 0xfffffff;
 141 }
 142
 143 static uint32_t gnu_hash(const char *s0)
 144 {
 145         const unsigned char *s = (void *)s0;
 146         uint_fast32_t h = 5381;
 147         for (; *s; s++)
 148                 h = h*33 + *s;
 149         return h;
 150 }
 151
 152 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 153 {
 154         size_t i;
 155         Sym *syms = dso->syms;
 156         uint32_t *hashtab = dso->hashtab;
 157         char *strings = dso->strings;
 158         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 159                 if (!strcmp(s, strings+syms[i].st_name))
 160                         return syms+i;
 161         }
 162         return 0;
 163 }
 164
 165 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 166 {
 167         Sym *sym;
 168         char *strings;
 169         uint32_t *hashtab = dso->ghashtab;
 170         uint32_t nbuckets = hashtab[0];
 171         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 172         uint32_t h2;
 173         uint32_t *hashval;
 174         uint32_t n = buckets[h1 % nbuckets];
 175
 176         if (!n) return 0;
 177
 178         strings = dso->strings;
 179         sym = dso->syms + n;
 180         hashval = buckets + nbuckets + (n - hashtab[1]);
 181
 182         for (h1 |= 1; ; sym++) {
 183                 h2 = *hashval++;
 184                 if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name))
 185                         return sym;
 186                 if (h2 & 1) break;
 187         }
 188
 189         return 0;
 190 }
 191
 192 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 193 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 194
 195 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 196 {
 197         uint32_t h = 0, gh = 0;
 198         struct symdef def = {0};
 199         if (dso->ghashtab) {
 200                 gh = gnu_hash(s);
 201                 if (gh == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 202         } else {
 203                 h = sysv_hash(s);
 204                 if (h == 0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 205         }
 206         for (; dso; dso=dso->next) {
 207                 Sym *sym;
 208                 if (!dso->global) continue;
 209                 if (dso->ghashtab) {
 210                         if (!gh) gh = gnu_hash(s);
 211                         sym = gnu_lookup(s, gh, dso);
 212                 } else {
 213                         if (!h) h = sysv_hash(s);
 214                         sym = sysv_lookup(s, h, dso);
 215                 }
 216                 if (!sym) continue;
 217                 if (!sym->st_shndx)
 218                         if (need_def || (sym->st_info&0xf) == STT_TLS)
 219                                 continue;
 220                 if (!sym->st_value)
 221                         if ((sym->st_info&0xf) != STT_TLS)
 222                                 continue;
 223                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 224                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 225
 226                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 227                 def.sym = sym;
 228                 def.dso = dso;
 229                 if (sym->st_info>>4 == STB_GLOBAL) break;
 230         }
 231         return def;
 232 }
 233
 234 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 235 {
 236         unsigned char *base = dso->base;
 237         Sym *syms = dso->syms;
 238         char *strings = dso->strings;
 239         Sym *sym;
 240         const char *name;
 241         void *ctx;
 242         int type;
 243         int sym_index;
 244         struct symdef def;
 245
 246         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 247                 type = R_TYPE(rel[1]);
 248                 sym_index = R_SYM(rel[1]);
 249                 if (sym_index) {
 250                         sym = syms + sym_index;
 251                         name = strings + sym->st_name;
 252                         ctx = IS_COPY(type) ? head->next : head;
 253                         def = find_sym(ctx, name, IS_PLT(type));
 254                         if (!def.sym && sym->st_info>>4 != STB_WEAK) {
 255                                 snprintf(errbuf, sizeof errbuf,
 256                                         "Error relocating %s: %s: symbol not found",
 257                                         dso->name, name);
 258                                 if (runtime) longjmp(*rtld_fail, 1);
 259                                 dprintf(2, "%s\n", errbuf);
 260                                 ldso_fail = 1;
 261                                 continue;
 262                         }
 263                 } else {
 264                         sym = 0;
 265                         def.sym = 0;
 266                         def.dso = 0;
 267                 }
 268                 do_single_reloc(dso, base, (void *)(base + rel[0]), type,
 269                         stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def,
 270                         def.sym?(size_t)(def.dso->base+def.sym->st_value):0);
 271         }
 272 }
 273
 274 /* A huge hack: to make up for the wastefulness of shared libraries
 275  * needing at least a page of dirty memory even if they have no global
 276  * data, we reclaim the gaps at the beginning and end of writable maps
 277  * and "donate" them to the heap by setting up minimal malloc
 278  * structures and then freeing them. */
 279
 280 static void reclaim(unsigned char *base, size_t start, size_t end)
 281 {
 282         size_t *a, *z;
 283         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 284         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 285         if (start>end || end-start < 4*sizeof(size_t)) return;
 286         a = (size_t *)(base + start);
 287         z = (size_t *)(base + end);
 288         a[-2] = 1;
 289         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 290         z[1] = 1;
 291         free(a);
 292 }
 293
 294 static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phcnt)
 295 {
 296         for (; phcnt--; ph=(void *)((char *)ph+phent)) {
 297                 if (ph->p_type!=PT_LOAD) continue;
 298                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 299                 reclaim(base, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 300                 reclaim(base, ph->p_vaddr+ph->p_memsz,
 301                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 302         }
 303 }
 304
 305 static void *map_library(int fd, struct dso *dso)
 306 {
 307         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 308         size_t phsize;
 309         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 310         size_t this_min, this_max;
 311         off_t off_start;
 312         Ehdr *eh;
 313         Phdr *ph, *ph0;
 314         unsigned prot;
 315         unsigned char *map, *base;
 316         size_t dyn=0;
 317         size_t tls_image=0;
 318         size_t i;
 319
 320         ssize_t l = read(fd, buf, sizeof buf);
 321         if (l<(int)sizeof *eh) return 0;
 322         eh = buf;
 323         if (eh->e_type != ET_DYN && eh->e_type != ET_EXEC) {
 324                 errno = ENOEXEC;
 325                 return 0;
 326         }
 327         phsize = eh->e_phentsize * eh->e_phnum;
 328         if (phsize + sizeof *eh > l) return 0;
 329         if (eh->e_phoff + phsize > l) {
 330                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 331                 if (l != phsize) return 0;
 332                 ph = ph0 = (void *)(buf + 1);
 333         } else {
 334                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 335         }
 336         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 337                 if (ph->p_type == PT_DYNAMIC)
 338                         dyn = ph->p_vaddr;
 339                 if (ph->p_type == PT_TLS) {
 340                         tls_image = ph->p_vaddr;
 341                         dso->tls_align = ph->p_align;
 342                         dso->tls_len = ph->p_filesz;
 343                         dso->tls_size = ph->p_memsz;
 344                 }
 345                 if (ph->p_type != PT_LOAD) continue;
 346                 if (ph->p_vaddr < addr_min) {
 347                         addr_min = ph->p_vaddr;
 348                         off_start = ph->p_offset;
 349                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 350                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 351                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 352                 }
 353                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 354                         addr_max = ph->p_vaddr+ph->p_memsz;
 355                 }
 356         }
 357         if (!dyn) return 0;
 358         addr_max += PAGE_SIZE-1;
 359         addr_max &= -PAGE_SIZE;
 360         addr_min &= -PAGE_SIZE;
 361         off_start &= -PAGE_SIZE;
 362         map_len = addr_max - addr_min + off_start;
 363         /* The first time, we map too much, possibly even more than
 364          * the length of the file. This is okay because we will not
 365          * use the invalid part; we just need to reserve the right
 366          * amount of virtual address space to map over later. */
 367         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 368         if (map==MAP_FAILED) return 0;
 369         /* If the loaded file is not relocatable and the requested address is
 370          * not available, then the load operation must fail. */
 371         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 372                 errno = EBUSY;
 373                 goto error;
 374         }
 375         base = map - addr_min;
 376         dso->phdr = 0;
 377         dso->phnum = 0;
 378         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 379                 if (ph->p_type != PT_LOAD) continue;
 380                 /* Check if the programs headers are in this load segment, and
 381                  * if so, record the address for use by dl_iterate_phdr. */
 382                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 383                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 384                         dso->phdr = (void *)(base + ph->p_vaddr
 385                                 + (eh->e_phoff-ph->p_offset));
 386                         dso->phnum = eh->e_phnum;
 387                 }
 388                 /* Reuse the existing mapping for the lowest-address LOAD */
 389                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 390                 this_min = ph->p_vaddr & -PAGE_SIZE;
 391                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 392                 off_start = ph->p_offset & -PAGE_SIZE;
 393                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 394                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 395                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 396                 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 397                         goto error;
 398                 if (ph->p_memsz > ph->p_filesz) {
 399                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 400                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 401                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 402                         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)
 403                                 goto error;
 404                 }
 405         }
 406         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 407                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 408                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
 409                                 goto error;
 410                         break;
 411                 }
 412         if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum);
 413         dso->map = map;
 414         dso->map_len = map_len;
 415         dso->base = base;
 416         dso->dynv = (void *)(base+dyn);
 417         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 418         return map;
 419 error:
 420         munmap(map, map_len);
 421         return 0;
 422 }
 423
 424 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 425 {
 426         size_t l;
 427         int fd;
 428         for (;;) {
 429                 s += strspn(s, ":\n");
 430                 l = strcspn(s, ":\n");
 431                 if (l-1 >= INT_MAX) return -1;
 432                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
 433                         continue;
 434                 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 435                 s += l;
 436         }
 437 }
 438
 439 static void decode_dyn(struct dso *p)
 440 {
 441         size_t dyn[DYN_CNT] = {0};
 442         decode_vec(p->dynv, dyn, DYN_CNT);
 443         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 444         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 445         if (dyn[0]&(1<<DT_HASH))
 446                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 447         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 448                 p->ghashtab = (void *)(p->base + *dyn);
 449 }
 450
 451 static struct dso *load_library(const char *name)
 452 {
 453         char buf[2*NAME_MAX+2];
 454         const char *pathname;
 455         unsigned char *map;
 456         struct dso *p, temp_dso = {0};
 457         int fd;
 458         struct stat st;
 459         size_t alloc_size;
 460         int n_th = 0;
 461         int is_self = 0;
 462
 463         /* Catch and block attempts to reload the implementation itself */
 464         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 465                 static const char *rp, reserved[] =
 466                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 467                 char *z = strchr(name, '.');
 468                 if (z) {
 469                         size_t l = z-name;
 470                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 471                         if (*rp) {
 472                                 if (ldd_mode) {
 473                                         /* Track which names have been resolved
 474                                          * and only report each one once. */
 475                                         static unsigned reported;
 476                                         unsigned mask = 1U<<(rp-reserved);
 477                                         if (!(reported & mask)) {
 478                                                 reported |= mask;
 479                                                 dprintf(1, "\t%s => %s (%p)\n",
 480                                                         name, ldso->name,
 481                                                         ldso->base);
 482                                         }
 483                                 }
 484                                 is_self = 1;
 485                         }
 486                 }
 487         }
 488         if (!strcmp(name, ldso->name)) is_self = 1;
 489         if (is_self) {
 490                 if (!ldso->prev) {
 491                         tail->next = ldso;
 492                         ldso->prev = tail;
 493                         tail = ldso->next ? ldso->next : ldso;
 494                 }
 495                 return ldso;
 496         }
 497         if (strchr(name, '/')) {
 498                 pathname = name;
 499                 fd = open(name, O_RDONLY|O_CLOEXEC);
 500         } else {
 501                 /* Search for the name to see if it's already loaded */
 502                 for (p=head->next; p; p=p->next) {
 503                         if (p->shortname && !strcmp(p->shortname, name)) {
 504                                 p->refcnt++;
 505                                 return p;
 506                         }
 507                 }
 508                 if (strlen(name) > NAME_MAX) return 0;
 509                 fd = -1;
 510                 if (r_path) fd = path_open(name, r_path, buf, sizeof buf);
 511                 if (fd < 0 && env_path) fd = path_open(name, env_path, buf, sizeof buf);
 512                 if (fd < 0) {
 513                         if (!sys_path) {
 514                                 char *prefix = 0;
 515                                 size_t prefix_len;
 516                                 if (ldso->name[0]=='/') {
 517                                         char *s, *t, *z;
 518                                         for (s=t=z=ldso->name; *s; s++)
 519                                                 if (*s=='/') z=t, t=s;
 520                                         prefix_len = z-ldso->name;
 521                                         if (prefix_len < PATH_MAX)
 522                                                 prefix = ldso->name;
 523                                 }
 524                                 if (!prefix) {
 525                                         prefix = "";
 526                                         prefix_len = 0;
 527                                 }
 528                                 char etc_ldso_path[prefix_len + 1
 529                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 530                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 531                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 532                                         (int)prefix_len, prefix);
 533                                 FILE *f = fopen(etc_ldso_path, "rbe");
 534                                 if (f) {
 535                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 536                                                 free(sys_path);
 537                                                 sys_path = "";
 538                                         }
 539                                         fclose(f);
 540                                 }
 541                         }
 542                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 543                         fd = path_open(name, sys_path, buf, sizeof buf);
 544                 }
 545                 pathname = buf;
 546         }
 547         if (fd < 0) return 0;
 548         if (fstat(fd, &st) < 0) {
 549                 close(fd);
 550                 return 0;
 551         }
 552         for (p=head->next; p; p=p->next) {
 553                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 554                         /* If this library was previously loaded with a
 555                          * pathname but a search found the same inode,
 556                          * setup its shortname so it can be found by name. */
 557                         if (!p->shortname && pathname != name)
 558                                 p->shortname = strrchr(p->name, '/')+1;
 559                         close(fd);
 560                         p->refcnt++;
 561                         return p;
 562                 }
 563         }
 564         map = noload ? 0 : map_library(fd, &temp_dso);
 565         close(fd);
 566         if (!map) return 0;
 567
 568         /* Allocate storage for the new DSO. When there is TLS, this
 569          * storage must include a reservation for all pre-existing
 570          * threads to obtain copies of both the new TLS, and an
 571          * extended DTV capable of storing an additional slot for
 572          * the newly-loaded DSO. */
 573         alloc_size = sizeof *p + strlen(pathname) + 1;
 574         if (runtime && temp_dso.tls_image) {
 575                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 576                         + sizeof(void *) * (tls_cnt+3);
 577                 n_th = libc.threads_minus_1 + 1;
 578                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 579                 else alloc_size += n_th * per_th;
 580         }
 581         p = calloc(1, alloc_size);
 582         if (!p) {
 583                 munmap(map, temp_dso.map_len);
 584                 return 0;
 585         }
 586         memcpy(p, &temp_dso, sizeof temp_dso);
 587         decode_dyn(p);
 588         p->dev = st.st_dev;
 589         p->ino = st.st_ino;
 590         p->refcnt = 1;
 591         p->name = p->buf;
 592         strcpy(p->name, pathname);
 593         /* Add a shortname only if name arg was not an explicit pathname. */
 594         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 595         if (p->tls_image) {
 596                 if (runtime && !__pthread_self_init()) {
 597                         munmap(map, p->map_len);
 598                         free(p);
 599                         return 0;
 600                 }
 601                 p->tls_id = ++tls_cnt;
 602                 tls_align = MAXP2(tls_align, p->tls_align);
 603 #ifdef TLS_ABOVE_TP
 604                 p->tls_offset = tls_offset + ( (tls_align-1) &
 605                         -(tls_offset + (uintptr_t)p->tls_image) );
 606                 tls_offset += p->tls_size;
 607 #else
 608                 tls_offset += p->tls_size + p->tls_align - 1;
 609                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 610                         & (p->tls_align-1);
 611                 p->tls_offset = tls_offset;
 612 #endif
 613                 p->new_dtv = (void *)(-sizeof(size_t) &
 614                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 615                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 616         }
 617
 618         tail->next = p;
 619         p->prev = tail;
 620         tail = p;
 621
 622         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 623
 624         return p;
 625 }
 626
 627 static void load_deps(struct dso *p)
 628 {
 629         size_t i, ndeps=0;
 630         struct dso ***deps = &p->deps, **tmp, *dep;
 631         for (; p; p=p->next) {
 632                 for (i=0; p->dynv[i]; i+=2) {
 633                         if (p->dynv[i] != DT_RPATH) continue;
 634                         r_path = (void *)(p->strings + p->dynv[i+1]);
 635                 }
 636                 for (i=0; p->dynv[i]; i+=2) {
 637                         if (p->dynv[i] != DT_NEEDED) continue;
 638                         dep = load_library(p->strings + p->dynv[i+1]);
 639                         if (!dep) {
 640                                 snprintf(errbuf, sizeof errbuf,
 641                                         "Error loading shared library %s: %m (needed by %s)",
 642                                         p->strings + p->dynv[i+1], p->name);
 643                                 if (runtime) longjmp(*rtld_fail, 1);
 644                                 dprintf(2, "%s\n", errbuf);
 645                                 ldso_fail = 1;
 646                                 continue;
 647                         }
 648                         if (runtime) {
 649                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 650                                 if (!tmp) longjmp(*rtld_fail, 1);
 651                                 tmp[ndeps++] = dep;
 652                                 tmp[ndeps] = 0;
 653                                 *deps = tmp;
 654                         }
 655                 }
 656                 r_path = 0;
 657         }
 658 }
 659
 660 static void load_preload(char *s)
 661 {
 662         int tmp;
 663         char *z;
 664         for (z=s; *z; s=z) {
 665                 for (   ; *s && isspace(*s); s++);
 666                 for (z=s; *z && !isspace(*z); z++);
 667                 tmp = *z;
 668                 *z = 0;
 669                 load_library(s);
 670                 *z = tmp;
 671         }
 672 }
 673
 674 static void make_global(struct dso *p)
 675 {
 676         for (; p; p=p->next) p->global = 1;
 677 }
 678
 679 static void reloc_all(struct dso *p)
 680 {
 681         size_t dyn[DYN_CNT] = {0};
 682         for (; p; p=p->next) {
 683                 if (p->relocated) continue;
 684                 decode_vec(p->dynv, dyn, DYN_CNT);
 685 #ifdef NEED_ARCH_RELOCS
 686                 do_arch_relocs(p, head);
 687 #endif
 688                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 689                         2+(dyn[DT_PLTREL]==DT_RELA));
 690                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 691                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 692                 p->relocated = 1;
 693         }
 694 }
 695
 696 static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
 697 {
 698         for (; cnt--; ph = (void *)((char *)ph + stride))
 699                 if (ph->p_type == PT_DYNAMIC)
 700                         return ph->p_vaddr;
 701         return 0;
 702 }
 703
 704 static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p)
 705 {
 706         size_t min_addr = -1, max_addr = 0;
 707         for (; cnt--; ph = (void *)((char *)ph + stride)) {
 708                 if (ph->p_type != PT_LOAD) continue;
 709                 if (ph->p_vaddr < min_addr)
 710                         min_addr = ph->p_vaddr;
 711                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 712                         max_addr = ph->p_vaddr+ph->p_memsz;
 713         }
 714         min_addr &= -PAGE_SIZE;
 715         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 716         p->map = p->base + min_addr;
 717         p->map_len = max_addr - min_addr;
 718 }
 719
 720 static void do_fini()
 721 {
 722         struct dso *p;
 723         size_t dyn[DYN_CNT] = {0};
 724         for (p=fini_head; p; p=p->fini_next) {
 725                 if (!p->constructed) continue;
 726                 decode_vec(p->dynv, dyn, DYN_CNT);
 727                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
 728                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
 729                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
 730                         while (n--) ((void (*)(void))*--fn)();
 731                 }
 732 #ifndef NO_LEGACY_INITFINI
 733                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 734                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
 735 #endif
 736         }
 737 }
 738
 739 static void do_init_fini(struct dso *p)
 740 {
 741         size_t dyn[DYN_CNT] = {0};
 742         int need_locking = libc.threads_minus_1;
 743         /* Allow recursive calls that arise when a library calls
 744          * dlopen from one of its constructors, but block any
 745          * other threads until all ctors have finished. */
 746         if (need_locking) pthread_mutex_lock(&init_fini_lock);
 747         for (; p; p=p->prev) {
 748                 if (p->constructed) continue;
 749                 p->constructed = 1;
 750                 decode_vec(p->dynv, dyn, DYN_CNT);
 751                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
 752                         p->fini_next = fini_head;
 753                         fini_head = p;
 754                 }
 755 #ifndef NO_LEGACY_INITFINI
 756                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 757                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
 758 #endif
 759                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
 760                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
 761                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
 762                         while (n--) ((void (*)(void))*fn++)();
 763                 }
 764                 if (!need_locking && libc.threads_minus_1) {
 765                         need_locking = 1;
 766                         pthread_mutex_lock(&init_fini_lock);
 767                 }
 768         }
 769         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 770 }
 771
 772 void _dl_debug_state(void)
 773 {
 774 }
 775
 776 void *__copy_tls(unsigned char *mem)
 777 {
 778         pthread_t td;
 779         struct dso *p;
 780
 781         if (!tls_cnt) return mem;
 782
 783         void **dtv = (void *)mem;
 784         dtv[0] = (void *)tls_cnt;
 785
 786 #ifdef TLS_ABOVE_TP
 787         mem += sizeof(void *) * (tls_cnt+1);
 788         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
 789         td = (pthread_t)mem;
 790         mem += sizeof(struct pthread);
 791
 792         for (p=head; p; p=p->next) {
 793                 if (!p->tls_id) continue;
 794                 dtv[p->tls_id] = mem + p->tls_offset;
 795                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 796         }
 797 #else
 798         mem += libc.tls_size - sizeof(struct pthread);
 799         mem -= (uintptr_t)mem & (tls_align-1);
 800         td = (pthread_t)mem;
 801
 802         for (p=head; p; p=p->next) {
 803                 if (!p->tls_id) continue;
 804                 dtv[p->tls_id] = mem - p->tls_offset;
 805                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 806         }
 807 #endif
 808         td->dtv = dtv;
 809         return td;
 810 }
 811
 812 void *__tls_get_addr(size_t *v)
 813 {
 814         pthread_t self = __pthread_self();
 815         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
 816                 return (char *)self->dtv[v[0]]+v[1];
 817
 818         /* Block signals to make accessing new TLS async-signal-safe */
 819         sigset_t set;
 820         pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
 821         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
 822                 pthread_sigmask(SIG_SETMASK, &set, 0);
 823                 return (char *)self->dtv[v[0]]+v[1];
 824         }
 825
 826         /* This is safe without any locks held because, if the caller
 827          * is able to request the Nth entry of the DTV, the DSO list
 828          * must be valid at least that far out and it was synchronized
 829          * at program startup or by an already-completed call to dlopen. */
 830         struct dso *p;
 831         for (p=head; p->tls_id != v[0]; p=p->next);
 832
 833         /* Get new DTV space from new DSO if needed */
 834         if (v[0] > (size_t)self->dtv[0]) {
 835                 void **newdtv = p->new_dtv +
 836                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
 837                 memcpy(newdtv, self->dtv,
 838                         ((size_t)self->dtv[0]+1) * sizeof(void *));
 839                 newdtv[0] = (void *)v[0];
 840                 self->dtv = newdtv;
 841         }
 842
 843         /* Get new TLS memory from new DSO */
 844         unsigned char *mem = p->new_tls +
 845                 (p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1);
 846         mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1);
 847         self->dtv[v[0]] = mem;
 848         memcpy(mem, p->tls_image, p->tls_len);
 849         pthread_sigmask(SIG_SETMASK, &set, 0);
 850         return mem + v[1];
 851 }
 852
 853 static void update_tls_size()
 854 {
 855         libc.tls_size = ALIGN(
 856                 (1+tls_cnt) * sizeof(void *) +
 857                 tls_offset +
 858                 sizeof(struct pthread) +
 859                 tls_align * 2,
 860         tls_align);
 861 }
 862
 863 void *__dynlink(int argc, char **argv)
 864 {
 865         size_t aux[AUX_CNT] = {0};
 866         size_t i;
 867         Phdr *phdr;
 868         Ehdr *ehdr;
 869         static struct dso builtin_dsos[3];
 870         struct dso *const app = builtin_dsos+0;
 871         struct dso *const lib = builtin_dsos+1;
 872         struct dso *const vdso = builtin_dsos+2;
 873         char *env_preload=0;
 874         size_t vdso_base;
 875         size_t *auxv;
 876         char **envp = argv+argc+1;
 877
 878         /* Find aux vector just past environ[] */
 879         for (i=argc+1; argv[i]; i++)
 880                 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
 881                         env_path = argv[i]+16;
 882                 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
 883                         env_preload = argv[i]+11;
 884         auxv = (void *)(argv+i+1);
 885
 886         decode_vec(auxv, aux, AUX_CNT);
 887
 888         /* Only trust user/env if kernel says we're not suid/sgid */
 889         if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
 890           || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
 891                 env_path = 0;
 892                 env_preload = 0;
 893         }
 894
 895         /* If the dynamic linker was invoked as a program itself, AT_BASE
 896          * will not be set. In that case, we assume the base address is
 897          * the start of the page containing the PHDRs; I don't know any
 898          * better approach... */
 899         if (!aux[AT_BASE]) {
 900                 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
 901                 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
 902         }
 903
 904         /* The dynamic linker load address is passed by the kernel
 905          * in the AUX vector, so this is easy. */
 906         lib->base = (void *)aux[AT_BASE];
 907         lib->name = lib->shortname = "libc.so";
 908         lib->global = 1;
 909         ehdr = (void *)lib->base;
 910         lib->phnum = ehdr->e_phnum;
 911         lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
 912         find_map_range(lib->phdr, ehdr->e_phnum, ehdr->e_phentsize, lib);
 913         lib->dynv = (void *)(lib->base + find_dyn(lib->phdr,
 914                 ehdr->e_phnum, ehdr->e_phentsize));
 915         decode_dyn(lib);
 916
 917         if (aux[AT_PHDR]) {
 918                 size_t interp_off = 0;
 919                 size_t tls_image = 0;
 920                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
 921                 app->phdr = phdr = (void *)aux[AT_PHDR];
 922                 app->phnum = aux[AT_PHNUM];
 923                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
 924                         if (phdr->p_type == PT_PHDR)
 925                                 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
 926                         else if (phdr->p_type == PT_INTERP)
 927                                 interp_off = (size_t)phdr->p_vaddr;
 928                         else if (phdr->p_type == PT_TLS) {
 929                                 tls_image = phdr->p_vaddr;
 930                                 app->tls_len = phdr->p_filesz;
 931                                 app->tls_size = phdr->p_memsz;
 932                                 app->tls_align = phdr->p_align;
 933                         }
 934                 }
 935                 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
 936                 if (interp_off) lib->name = (char *)app->base + interp_off;
 937                 app->name = argv[0];
 938                 app->dynv = (void *)(app->base + find_dyn(
 939                         (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
 940                 find_map_range((void *)aux[AT_PHDR],
 941                         aux[AT_PHNUM], aux[AT_PHENT], app);
 942         } else {
 943                 int fd;
 944                 char *ldname = argv[0];
 945                 size_t l = strlen(ldname);
 946                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
 947                 *argv++ = (void *)-1;
 948                 if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
 949                 if (!argv[0]) {
 950                         dprintf(2, "musl libc/dynamic program loader\n");
 951                         dprintf(2, "usage: %s pathname%s\n", ldname,
 952                                 ldd_mode ? "" : " [args]");
 953                         _exit(1);
 954                 }
 955                 fd = open(argv[0], O_RDONLY);
 956                 if (fd < 0) {
 957                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
 958                         _exit(1);
 959                 }
 960                 runtime = 1;
 961                 ehdr = (void *)map_library(fd, app);
 962                 if (!ehdr) {
 963                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
 964                         _exit(1);
 965                 }
 966                 runtime = 0;
 967                 close(fd);
 968                 lib->name = ldname;
 969                 app->name = argv[0];
 970                 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
 971                 /* Find the name that would have been used for the dynamic
 972                  * linker had ldd not taken its place. */
 973                 if (ldd_mode) {
 974                         for (i=0; i<app->phnum; i++) {
 975                                 if (app->phdr[i].p_type == PT_INTERP)
 976                                         lib->name = (void *)(app->base
 977                                                 + app->phdr[i].p_vaddr);
 978                         }
 979                         dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
 980                 }
 981         }
 982         if (app->tls_size) {
 983                 app->tls_id = tls_cnt = 1;
 984 #ifdef TLS_ABOVE_TP
 985                 app->tls_offset = 0;
 986                 tls_offset = app->tls_size
 987                         + ( -((uintptr_t)app->tls_image + app->tls_size)
 988                         & (app->tls_align-1) );
 989 #else
 990                 tls_offset = app->tls_offset = app->tls_size
 991                         + ( -((uintptr_t)app->tls_image + app->tls_size)
 992                         & (app->tls_align-1) );
 993 #endif
 994                 tls_align = MAXP2(tls_align, app->tls_align);
 995         }
 996         app->global = 1;
 997         decode_dyn(app);
 998
 999         /* Attach to vdso, if provided by the kernel */
1000         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1001                 ehdr = (void *)vdso_base;
1002                 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1003                 vdso->phnum = ehdr->e_phnum;
1004                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1005                         if (phdr->p_type == PT_DYNAMIC)
1006                                 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1007                         if (phdr->p_type == PT_LOAD)
1008                                 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1009                 }
1010                 vdso->name = "";
1011                 vdso->shortname = "linux-gate.so.1";
1012                 vdso->global = 1;
1013                 decode_dyn(vdso);
1014                 vdso->prev = lib;
1015                 lib->next = vdso;
1016         }
1017
1018         /* Initial dso chain consists only of the app. We temporarily
1019          * append the dynamic linker/libc so we can relocate it, then
1020          * restore the initial chain in preparation for loading third
1021          * party libraries (preload/needed). */
1022         head = tail = app;
1023         ldso = lib;
1024         app->next = lib;
1025         reloc_all(lib);
1026         app->next = 0;
1027
1028         /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1029
1030         /* Donate unused parts of app and library mapping to malloc */
1031         reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
1032         ehdr = (void *)lib->base;
1033         reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
1034                 ehdr->e_phentsize, ehdr->e_phnum);
1035
1036         /* Load preload/needed libraries, add their symbols to the global
1037          * namespace, and perform all remaining relocations. The main
1038          * program must be relocated LAST since it may contain copy
1039          * relocations which depend on libraries' relocations. */
1040         if (env_preload) load_preload(env_preload);
1041         load_deps(app);
1042         make_global(app);
1043
1044         reloc_all(app->next);
1045         reloc_all(app);
1046
1047         update_tls_size();
1048         if (tls_cnt) {
1049                 void *mem = mmap(0, libc.tls_size, PROT_READ|PROT_WRITE,
1050                         MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1051                 if (mem==MAP_FAILED ||
1052                     !__install_initial_tls(__copy_tls(mem))) {
1053                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1054                                 argv[0], libc.tls_size);
1055                         _exit(127);
1056                 }
1057         }
1058
1059         if (ldso_fail) _exit(127);
1060         if (ldd_mode) _exit(0);
1061
1062         /* Switch to runtime mode: any further failures in the dynamic
1063          * linker are a reportable failure rather than a fatal startup
1064          * error. If the dynamic loader (dlopen) will not be used, free
1065          * all memory used by the dynamic linker. */
1066         runtime = 1;
1067
1068 #ifndef DYNAMIC_IS_RO
1069         for (i=0; app->dynv[i]; i+=2)
1070                 if (app->dynv[i]==DT_DEBUG)
1071                         app->dynv[i+1] = (size_t)&debug;
1072 #endif
1073         debug.ver = 1;
1074         debug.bp = _dl_debug_state;
1075         debug.head = head;
1076         debug.base = lib->base;
1077         debug.state = 0;
1078         _dl_debug_state();
1079
1080         if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]);
1081         __init_libc(envp, argv[0]);
1082         atexit(do_fini);
1083         errno = 0;
1084         do_init_fini(tail);
1085
1086         return (void *)aux[AT_ENTRY];
1087 }
1088
1089 void *dlopen(const char *file, int mode)
1090 {
1091         struct dso *volatile p, *orig_tail, *next;
1092         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1093         size_t i;
1094         int cs;
1095         jmp_buf jb;
1096
1097         if (!file) return head;
1098
1099         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1100         pthread_rwlock_wrlock(&lock);
1101         __inhibit_ptc();
1102
1103         p = 0;
1104         orig_tls_cnt = tls_cnt;
1105         orig_tls_offset = tls_offset;
1106         orig_tls_align = tls_align;
1107         orig_tail = tail;
1108         noload = mode & RTLD_NOLOAD;
1109
1110         rtld_fail = &jb;
1111         if (setjmp(*rtld_fail)) {
1112                 /* Clean up anything new that was (partially) loaded */
1113                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1114                         if (p->deps[i]->global < 0)
1115                                 p->deps[i]->global = 0;
1116                 for (p=orig_tail->next; p; p=next) {
1117                         next = p->next;
1118                         munmap(p->map, p->map_len);
1119                         free(p->deps);
1120                         free(p);
1121                 }
1122                 tls_cnt = orig_tls_cnt;
1123                 tls_offset = orig_tls_offset;
1124                 tls_align = orig_tls_align;
1125                 tail = orig_tail;
1126                 tail->next = 0;
1127                 p = 0;
1128                 errflag = 1;
1129                 goto end;
1130         } else p = load_library(file);
1131
1132         if (!p) {
1133                 snprintf(errbuf, sizeof errbuf, noload ?
1134                         "Library %s is not already loaded" :
1135                         "Error loading shared library %s: %m",
1136                         file);
1137                 errflag = 1;
1138                 goto end;
1139         }
1140
1141         /* First load handling */
1142         if (!p->deps) {
1143                 load_deps(p);
1144                 if (p->deps) for (i=0; p->deps[i]; i++)
1145                         if (!p->deps[i]->global)
1146                                 p->deps[i]->global = -1;
1147                 if (!p->global) p->global = -1;
1148                 reloc_all(p);
1149                 if (p->deps) for (i=0; p->deps[i]; i++)
1150                         if (p->deps[i]->global < 0)
1151                                 p->deps[i]->global = 0;
1152                 if (p->global < 0) p->global = 0;
1153         }
1154
1155         if (mode & RTLD_GLOBAL) {
1156                 if (p->deps) for (i=0; p->deps[i]; i++)
1157                         p->deps[i]->global = 1;
1158                 p->global = 1;
1159         }
1160
1161         update_tls_size();
1162
1163         if (ssp_used) __init_ssp(libc.auxv);
1164
1165         _dl_debug_state();
1166         orig_tail = tail;
1167 end:
1168         __release_ptc();
1169         if (p) gencnt++;
1170         pthread_rwlock_unlock(&lock);
1171         if (p) do_init_fini(orig_tail);
1172         pthread_setcancelstate(cs, 0);
1173         return p;
1174 }
1175
1176 static int invalid_dso_handle(void *h)
1177 {
1178         struct dso *p;
1179         for (p=head; p; p=p->next) if (h==p) return 0;
1180         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1181         errflag = 1;
1182         return 1;
1183 }
1184
1185 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1186 {
1187         size_t i;
1188         uint32_t h = 0, gh = 0;
1189         Sym *sym;
1190         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1191                 if (p == RTLD_DEFAULT) {
1192                         p = head;
1193                 } else if (p == RTLD_NEXT) {
1194                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1195                         if (!p) p=head;
1196                         p = p->next;
1197                 }
1198                 struct symdef def = find_sym(p, s, 0);
1199                 if (!def.sym) goto failed;
1200                 if ((def.sym->st_info&0xf) == STT_TLS)
1201                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1202                 return def.dso->base + def.sym->st_value;
1203         }
1204         if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1205                 return 0;
1206         if (p->ghashtab) {
1207                 gh = gnu_hash(s);
1208                 sym = gnu_lookup(s, gh, p);
1209         } else {
1210                 h = sysv_hash(s);
1211                 sym = sysv_lookup(s, h, p);
1212         }
1213         if (sym && (sym->st_info&0xf) == STT_TLS)
1214                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1215         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1216                 return p->base + sym->st_value;
1217         if (p->deps) for (i=0; p->deps[i]; i++) {
1218                 if (p->deps[i]->ghashtab) {
1219                         if (!gh) gh = gnu_hash(s);
1220                         sym = gnu_lookup(s, gh, p->deps[i]);
1221                 } else {
1222                         if (!h) h = sysv_hash(s);
1223                         sym = sysv_lookup(s, h, p->deps[i]);
1224                 }
1225                 if (sym && (sym->st_info&0xf) == STT_TLS)
1226                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1227                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1228                         return p->deps[i]->base + sym->st_value;
1229         }
1230 failed:
1231         errflag = 1;
1232         snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1233         return 0;
1234 }
1235
1236 int __dladdr(void *addr, Dl_info *info)
1237 {
1238         struct dso *p;
1239         Sym *sym;
1240         uint32_t nsym;
1241         char *strings;
1242         size_t i;
1243         void *best = 0;
1244         char *bestname;
1245
1246         pthread_rwlock_rdlock(&lock);
1247         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1248         pthread_rwlock_unlock(&lock);
1249
1250         if (!p) return 0;
1251
1252         sym = p->syms;
1253         strings = p->strings;
1254         if (p->hashtab) {
1255                 nsym = p->hashtab[1];
1256         } else {
1257                 uint32_t *buckets;
1258                 uint32_t *hashval;
1259                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1260                 sym += p->ghashtab[1];
1261                 for (i = 0; i < p->ghashtab[0]; i++) {
1262                         if (buckets[i] > nsym)
1263                                 nsym = buckets[i];
1264                 }
1265                 if (nsym) {
1266                         nsym -= p->ghashtab[1];
1267                         hashval = buckets + p->ghashtab[0] + nsym;
1268                         do nsym++;
1269                         while (!(*hashval++ & 1));
1270                 }
1271         }
1272
1273         for (; nsym; nsym--, sym++) {
1274                 if (sym->st_value
1275                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1276                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1277                         void *symaddr = p->base + sym->st_value;
1278                         if (symaddr > addr || symaddr < best)
1279                                 continue;
1280                         best = symaddr;
1281                         bestname = strings + sym->st_name;
1282                         if (addr == symaddr)
1283                                 break;
1284                 }
1285         }
1286
1287         if (!best) return 0;
1288
1289         info->dli_fname = p->name;
1290         info->dli_fbase = p->base;
1291         info->dli_sname = bestname;
1292         info->dli_saddr = best;
1293
1294         return 1;
1295 }
1296
1297 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1298 {
1299         void *res;
1300         pthread_rwlock_rdlock(&lock);
1301         res = do_dlsym(p, s, ra);
1302         pthread_rwlock_unlock(&lock);
1303         return res;
1304 }
1305
1306 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1307 {
1308         struct dso *current;
1309         struct dl_phdr_info info;
1310         int ret = 0;
1311         for(current = head; current;) {
1312                 info.dlpi_addr      = (uintptr_t)current->base;
1313                 info.dlpi_name      = current->name;
1314                 info.dlpi_phdr      = current->phdr;
1315                 info.dlpi_phnum     = current->phnum;
1316                 info.dlpi_adds      = gencnt;
1317                 info.dlpi_subs      = 0;
1318                 info.dlpi_tls_modid = current->tls_id;
1319                 info.dlpi_tls_data  = current->tls_image;
1320
1321                 ret = (callback)(&info, sizeof (info), data);
1322
1323                 if (ret != 0) break;
1324
1325                 pthread_rwlock_rdlock(&lock);
1326                 current = current->next;
1327                 pthread_rwlock_unlock(&lock);
1328         }
1329         return ret;
1330 }
1331 #else
1332 static int invalid_dso_handle(void *h)
1333 {
1334         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1335         errflag = 1;
1336         return 1;
1337 }
1338 void *dlopen(const char *file, int mode)
1339 {
1340         return 0;
1341 }
1342 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1343 {
1344         return 0;
1345 }
1346 int __dladdr (void *addr, Dl_info *info)
1347 {
1348         return 0;
1349 }
1350 #endif
1351
1352 int __dlinfo(void *dso, int req, void *res)
1353 {
1354         if (invalid_dso_handle(dso)) return -1;
1355         if (req != RTLD_DI_LINKMAP) {
1356                 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1357                 errflag = 1;
1358                 return -1;
1359         }
1360         *(struct link_map **)res = dso;
1361         return 0;
1362 }
1363
1364 char *dlerror()
1365 {
1366         if (!errflag) return 0;
1367         errflag = 0;
1368         return errbuf;
1369 }
1370
1371 int dlclose(void *p)
1372 {
1373         return invalid_dso_handle(p);
1374 }