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