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