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