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