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         int16_t *versym;
  67         char *strings;
  68         unsigned char *map;
  69         size_t map_len;
  70         dev_t dev;
  71         ino_t ino;
  72         signed char global;
  73         char relocated;
  74         char constructed;
  75         struct dso **deps, *needed_by;
  76         char *rpath;
  77         void *tls_image;
  78         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  79         void **new_dtv;
  80         unsigned char *new_tls;
  81         int new_dtv_idx, new_tls_idx;
  82         struct dso *fini_next;
  83         char *shortname;
  84         char buf[];
  85 };
  86
  87 struct symdef {
  88         Sym *sym;
  89         struct dso *dso;
  90 };
  91
  92 #include "reloc.h"
  93
  94 void __init_ssp(size_t *);
  95 void *__install_initial_tls(void *);
  96 void __init_libc(char **, char *);
  97
  98 static struct dso *head, *tail, *ldso, *fini_head;
  99 static char *env_path, *sys_path;
 100 static unsigned long long gencnt;
 101 static int ssp_used;
 102 static int runtime;
 103 static int ldd_mode;
 104 static int ldso_fail;
 105 static int noload;
 106 static jmp_buf *rtld_fail;
 107 static pthread_rwlock_t lock;
 108 static struct debug debug;
 109 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
 110 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 111
 112 struct debug *_dl_debug_addr = &debug;
 113
 114 #define AUX_CNT 38
 115 #define DYN_CNT 34
 116
 117 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 118 {
 119         memset(a, 0, cnt*sizeof(size_t));
 120         for (; v[0]; v+=2) if (v[0]<cnt) {
 121                 a[0] |= 1ULL<<v[0];
 122                 a[v[0]] = v[1];
 123         }
 124 }
 125
 126 static int search_vec(size_t *v, size_t *r, size_t key)
 127 {
 128         for (; v[0]!=key; v+=2)
 129                 if (!v[0]) return 0;
 130         *r = v[1];
 131         return 1;
 132 }
 133
 134 static uint32_t sysv_hash(const char *s0)
 135 {
 136         const unsigned char *s = (void *)s0;
 137         uint_fast32_t h = 0;
 138         while (*s) {
 139                 h = 16*h + *s++;
 140                 h ^= h>>24 & 0xf0;
 141         }
 142         return h & 0xfffffff;
 143 }
 144
 145 static uint32_t gnu_hash(const char *s0)
 146 {
 147         const unsigned char *s = (void *)s0;
 148         uint_fast32_t h = 5381;
 149         for (; *s; s++)
 150                 h = h*33 + *s;
 151         return h;
 152 }
 153
 154 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 155 {
 156         size_t i;
 157         Sym *syms = dso->syms;
 158         uint32_t *hashtab = dso->hashtab;
 159         char *strings = dso->strings;
 160         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 161                 if ((!dso->versym || dso->versym[i] >= 0)
 162                     && (!strcmp(s, strings+syms[i].st_name)))
 163                         return syms+i;
 164         }
 165         return 0;
 166 }
 167
 168 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 169 {
 170         Sym *syms = dso->syms;
 171         char *strings = dso->strings;
 172         uint32_t *hashtab = dso->ghashtab;
 173         uint32_t nbuckets = hashtab[0];
 174         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 175         uint32_t h2;
 176         uint32_t *hashval;
 177         uint32_t i = buckets[h1 % nbuckets];
 178
 179         if (!i) return 0;
 180
 181         hashval = buckets + nbuckets + (i - hashtab[1]);
 182
 183         for (h1 |= 1; ; i++) {
 184                 h2 = *hashval++;
 185                 if ((!dso->versym || dso->versym[i] >= 0)
 186                     && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
 187                         return syms+i;
 188                 if (h2 & 1) break;
 189         }
 190
 191         return 0;
 192 }
 193
 194 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 195 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 196
 197 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 198 {
 199         uint32_t h = 0, gh = 0;
 200         struct symdef def = {0};
 201         if (dso->ghashtab) {
 202                 gh = gnu_hash(s);
 203                 if (gh == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 204         } else {
 205                 h = sysv_hash(s);
 206                 if (h == 0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 207         }
 208         for (; dso; dso=dso->next) {
 209                 Sym *sym;
 210                 if (!dso->global) continue;
 211                 if (dso->ghashtab) {
 212                         if (!gh) gh = gnu_hash(s);
 213                         sym = gnu_lookup(s, gh, dso);
 214                 } else {
 215                         if (!h) h = sysv_hash(s);
 216                         sym = sysv_lookup(s, h, dso);
 217                 }
 218                 if (!sym) continue;
 219                 if (!sym->st_shndx)
 220                         if (need_def || (sym->st_info&0xf) == STT_TLS)
 221                                 continue;
 222                 if (!sym->st_value)
 223                         if ((sym->st_info&0xf) != STT_TLS)
 224                                 continue;
 225                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 226                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 227
 228                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 229                 def.sym = sym;
 230                 def.dso = dso;
 231                 if (sym->st_info>>4 == STB_GLOBAL) break;
 232         }
 233         return def;
 234 }
 235
 236 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 237 {
 238         unsigned char *base = dso->base;
 239         Sym *syms = dso->syms;
 240         char *strings = dso->strings;
 241         Sym *sym;
 242         const char *name;
 243         void *ctx;
 244         int type;
 245         int sym_index;
 246         struct symdef def;
 247
 248         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 249                 type = R_TYPE(rel[1]);
 250                 sym_index = R_SYM(rel[1]);
 251                 if (sym_index) {
 252                         sym = syms + sym_index;
 253                         name = strings + sym->st_name;
 254                         ctx = IS_COPY(type) ? head->next : head;
 255                         def = find_sym(ctx, name, IS_PLT(type));
 256                         if (!def.sym && sym->st_info>>4 != STB_WEAK) {
 257                                 snprintf(errbuf, sizeof errbuf,
 258                                         "Error relocating %s: %s: symbol not found",
 259                                         dso->name, name);
 260                                 if (runtime) longjmp(*rtld_fail, 1);
 261                                 dprintf(2, "%s\n", errbuf);
 262                                 ldso_fail = 1;
 263                                 continue;
 264                         }
 265                 } else {
 266                         sym = 0;
 267                         def.sym = 0;
 268                         def.dso = 0;
 269                 }
 270                 do_single_reloc(dso, base, (void *)(base + rel[0]), type,
 271                         stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def,
 272                         def.sym?(size_t)(def.dso->base+def.sym->st_value):0);
 273         }
 274 }
 275
 276 /* A huge hack: to make up for the wastefulness of shared libraries
 277  * needing at least a page of dirty memory even if they have no global
 278  * data, we reclaim the gaps at the beginning and end of writable maps
 279  * and "donate" them to the heap by setting up minimal malloc
 280  * structures and then freeing them. */
 281
 282 static void reclaim(unsigned char *base, size_t start, size_t end)
 283 {
 284         size_t *a, *z;
 285         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 286         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 287         if (start>end || end-start < 4*sizeof(size_t)) return;
 288         a = (size_t *)(base + start);
 289         z = (size_t *)(base + end);
 290         a[-2] = 1;
 291         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 292         z[1] = 1;
 293         free(a);
 294 }
 295
 296 static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phcnt)
 297 {
 298         for (; phcnt--; ph=(void *)((char *)ph+phent)) {
 299                 if (ph->p_type!=PT_LOAD) continue;
 300                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 301                 reclaim(base, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 302                 reclaim(base, ph->p_vaddr+ph->p_memsz,
 303                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 304         }
 305 }
 306
 307 static void *map_library(int fd, struct dso *dso)
 308 {
 309         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 310         void *allocated_buf=0;
 311         size_t phsize;
 312         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 313         size_t this_min, this_max;
 314         off_t off_start;
 315         Ehdr *eh;
 316         Phdr *ph, *ph0;
 317         unsigned prot;
 318         unsigned char *map=MAP_FAILED, *base;
 319         size_t dyn=0;
 320         size_t tls_image=0;
 321         size_t i;
 322
 323         ssize_t l = read(fd, buf, sizeof buf);
 324         eh = buf;
 325         if (l<0) return 0;
 326         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 327                 goto noexec;
 328         phsize = eh->e_phentsize * eh->e_phnum;
 329         if (phsize > sizeof buf - sizeof *eh) {
 330                 allocated_buf = malloc(phsize);
 331                 if (!allocated_buf) return 0;
 332                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 333                 if (l < 0) goto error;
 334                 if (l != phsize) goto noexec;
 335                 ph = ph0 = allocated_buf;
 336         } else if (eh->e_phoff + phsize > l) {
 337                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 338                 if (l < 0) goto error;
 339                 if (l != phsize) goto noexec;
 340                 ph = ph0 = (void *)(buf + 1);
 341         } else {
 342                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 343         }
 344         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 345                 if (ph->p_type == PT_DYNAMIC)
 346                         dyn = ph->p_vaddr;
 347                 if (ph->p_type == PT_TLS) {
 348                         tls_image = ph->p_vaddr;
 349                         dso->tls_align = ph->p_align;
 350                         dso->tls_len = ph->p_filesz;
 351                         dso->tls_size = ph->p_memsz;
 352                 }
 353                 if (ph->p_type != PT_LOAD) continue;
 354                 if (ph->p_vaddr < addr_min) {
 355                         addr_min = ph->p_vaddr;
 356                         off_start = ph->p_offset;
 357                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 358                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 359                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 360                 }
 361                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 362                         addr_max = ph->p_vaddr+ph->p_memsz;
 363                 }
 364         }
 365         if (!dyn) goto noexec;
 366         addr_max += PAGE_SIZE-1;
 367         addr_max &= -PAGE_SIZE;
 368         addr_min &= -PAGE_SIZE;
 369         off_start &= -PAGE_SIZE;
 370         map_len = addr_max - addr_min + off_start;
 371         /* The first time, we map too much, possibly even more than
 372          * the length of the file. This is okay because we will not
 373          * use the invalid part; we just need to reserve the right
 374          * amount of virtual address space to map over later. */
 375         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 376         if (map==MAP_FAILED) goto error;
 377         /* If the loaded file is not relocatable and the requested address is
 378          * not available, then the load operation must fail. */
 379         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 380                 errno = EBUSY;
 381                 goto error;
 382         }
 383         base = map - addr_min;
 384         dso->phdr = 0;
 385         dso->phnum = 0;
 386         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 387                 if (ph->p_type != PT_LOAD) continue;
 388                 /* Check if the programs headers are in this load segment, and
 389                  * if so, record the address for use by dl_iterate_phdr. */
 390                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 391                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 392                         dso->phdr = (void *)(base + ph->p_vaddr
 393                                 + (eh->e_phoff-ph->p_offset));
 394                         dso->phnum = eh->e_phnum;
 395                 }
 396                 /* Reuse the existing mapping for the lowest-address LOAD */
 397                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 398                 this_min = ph->p_vaddr & -PAGE_SIZE;
 399                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 400                 off_start = ph->p_offset & -PAGE_SIZE;
 401                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 402                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 403                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 404                 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 405                         goto error;
 406                 if (ph->p_memsz > ph->p_filesz) {
 407                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 408                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 409                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 410                         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)
 411                                 goto error;
 412                 }
 413         }
 414         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 415                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 416                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
 417                                 goto error;
 418                         break;
 419                 }
 420         if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum);
 421         dso->map = map;
 422         dso->map_len = map_len;
 423         dso->base = base;
 424         dso->dynv = (void *)(base+dyn);
 425         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 426         free(allocated_buf);
 427         return map;
 428 noexec:
 429         errno = ENOEXEC;
 430 error:
 431         if (map!=MAP_FAILED) munmap(map, map_len);
 432         free(allocated_buf);
 433         return 0;
 434 }
 435
 436 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 437 {
 438         size_t l;
 439         int fd;
 440         for (;;) {
 441                 s += strspn(s, ":\n");
 442                 l = strcspn(s, ":\n");
 443                 if (l-1 >= INT_MAX) return -1;
 444                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
 445                         continue;
 446                 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 447                 s += l;
 448         }
 449 }
 450
 451 static void decode_dyn(struct dso *p)
 452 {
 453         size_t dyn[DYN_CNT] = {0};
 454         decode_vec(p->dynv, dyn, DYN_CNT);
 455         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 456         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 457         if (dyn[0]&(1<<DT_HASH))
 458                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 459         if (dyn[0]&(1<<DT_RPATH))
 460                 p->rpath = (void *)(p->strings + dyn[DT_RPATH]);
 461         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 462                 p->ghashtab = (void *)(p->base + *dyn);
 463         if (search_vec(p->dynv, dyn, DT_VERSYM))
 464                 p->versym = (void *)(p->base + *dyn);
 465 }
 466
 467 static struct dso *load_library(const char *name, struct dso *needed_by)
 468 {
 469         char buf[2*NAME_MAX+2];
 470         const char *pathname;
 471         unsigned char *map;
 472         struct dso *p, temp_dso = {0};
 473         int fd;
 474         struct stat st;
 475         size_t alloc_size;
 476         int n_th = 0;
 477         int is_self = 0;
 478
 479         /* Catch and block attempts to reload the implementation itself */
 480         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 481                 static const char *rp, reserved[] =
 482                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 483                 char *z = strchr(name, '.');
 484                 if (z) {
 485                         size_t l = z-name;
 486                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 487                         if (*rp) {
 488                                 if (ldd_mode) {
 489                                         /* Track which names have been resolved
 490                                          * and only report each one once. */
 491                                         static unsigned reported;
 492                                         unsigned mask = 1U<<(rp-reserved);
 493                                         if (!(reported & mask)) {
 494                                                 reported |= mask;
 495                                                 dprintf(1, "\t%s => %s (%p)\n",
 496                                                         name, ldso->name,
 497                                                         ldso->base);
 498                                         }
 499                                 }
 500                                 is_self = 1;
 501                         }
 502                 }
 503         }
 504         if (!strcmp(name, ldso->name)) is_self = 1;
 505         if (is_self) {
 506                 if (!ldso->prev) {
 507                         tail->next = ldso;
 508                         ldso->prev = tail;
 509                         tail = ldso->next ? ldso->next : ldso;
 510                 }
 511                 return ldso;
 512         }
 513         if (strchr(name, '/')) {
 514                 pathname = name;
 515                 fd = open(name, O_RDONLY|O_CLOEXEC);
 516         } else {
 517                 /* Search for the name to see if it's already loaded */
 518                 for (p=head->next; p; p=p->next) {
 519                         if (p->shortname && !strcmp(p->shortname, name)) {
 520                                 p->refcnt++;
 521                                 return p;
 522                         }
 523                 }
 524                 if (strlen(name) > NAME_MAX) return 0;
 525                 fd = -1;
 526                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 527                 for (p=needed_by; fd < 0 && p; p=p->needed_by)
 528                         if (p->rpath)
 529                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 530                 if (fd < 0) {
 531                         if (!sys_path) {
 532                                 char *prefix = 0;
 533                                 size_t prefix_len;
 534                                 if (ldso->name[0]=='/') {
 535                                         char *s, *t, *z;
 536                                         for (s=t=z=ldso->name; *s; s++)
 537                                                 if (*s=='/') z=t, t=s;
 538                                         prefix_len = z-ldso->name;
 539                                         if (prefix_len < PATH_MAX)
 540                                                 prefix = ldso->name;
 541                                 }
 542                                 if (!prefix) {
 543                                         prefix = "";
 544                                         prefix_len = 0;
 545                                 }
 546                                 char etc_ldso_path[prefix_len + 1
 547                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 548                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 549                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 550                                         (int)prefix_len, prefix);
 551                                 FILE *f = fopen(etc_ldso_path, "rbe");
 552                                 if (f) {
 553                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 554                                                 free(sys_path);
 555                                                 sys_path = "";
 556                                         }
 557                                         fclose(f);
 558                                 }
 559                         }
 560                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 561                         fd = path_open(name, sys_path, buf, sizeof buf);
 562                 }
 563                 pathname = buf;
 564         }
 565         if (fd < 0) return 0;
 566         if (fstat(fd, &st) < 0) {
 567                 close(fd);
 568                 return 0;
 569         }
 570         for (p=head->next; p; p=p->next) {
 571                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 572                         /* If this library was previously loaded with a
 573                          * pathname but a search found the same inode,
 574                          * setup its shortname so it can be found by name. */
 575                         if (!p->shortname && pathname != name)
 576                                 p->shortname = strrchr(p->name, '/')+1;
 577                         close(fd);
 578                         p->refcnt++;
 579                         return p;
 580                 }
 581         }
 582         map = noload ? 0 : map_library(fd, &temp_dso);
 583         close(fd);
 584         if (!map) return 0;
 585
 586         /* Allocate storage for the new DSO. When there is TLS, this
 587          * storage must include a reservation for all pre-existing
 588          * threads to obtain copies of both the new TLS, and an
 589          * extended DTV capable of storing an additional slot for
 590          * the newly-loaded DSO. */
 591         alloc_size = sizeof *p + strlen(pathname) + 1;
 592         if (runtime && temp_dso.tls_image) {
 593                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 594                         + sizeof(void *) * (tls_cnt+3);
 595                 n_th = libc.threads_minus_1 + 1;
 596                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 597                 else alloc_size += n_th * per_th;
 598         }
 599         p = calloc(1, alloc_size);
 600         if (!p) {
 601                 munmap(map, temp_dso.map_len);
 602                 return 0;
 603         }
 604         memcpy(p, &temp_dso, sizeof temp_dso);
 605         decode_dyn(p);
 606         p->dev = st.st_dev;
 607         p->ino = st.st_ino;
 608         p->refcnt = 1;
 609         p->needed_by = needed_by;
 610         p->name = p->buf;
 611         strcpy(p->name, pathname);
 612         /* Add a shortname only if name arg was not an explicit pathname. */
 613         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 614         if (p->tls_image) {
 615                 if (runtime && !__pthread_self_init()) {
 616                         munmap(map, p->map_len);
 617                         free(p);
 618                         return 0;
 619                 }
 620                 p->tls_id = ++tls_cnt;
 621                 tls_align = MAXP2(tls_align, p->tls_align);
 622 #ifdef TLS_ABOVE_TP
 623                 p->tls_offset = tls_offset + ( (tls_align-1) &
 624                         -(tls_offset + (uintptr_t)p->tls_image) );
 625                 tls_offset += p->tls_size;
 626 #else
 627                 tls_offset += p->tls_size + p->tls_align - 1;
 628                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 629                         & (p->tls_align-1);
 630                 p->tls_offset = tls_offset;
 631 #endif
 632                 p->new_dtv = (void *)(-sizeof(size_t) &
 633                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 634                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 635         }
 636
 637         tail->next = p;
 638         p->prev = tail;
 639         tail = p;
 640
 641         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 642
 643         return p;
 644 }
 645
 646 static void load_deps(struct dso *p)
 647 {
 648         size_t i, ndeps=0;
 649         struct dso ***deps = &p->deps, **tmp, *dep;
 650         for (; p; p=p->next) {
 651                 for (i=0; p->dynv[i]; i+=2) {
 652                         if (p->dynv[i] != DT_NEEDED) continue;
 653                         dep = load_library(p->strings + p->dynv[i+1], p);
 654                         if (!dep) {
 655                                 snprintf(errbuf, sizeof errbuf,
 656                                         "Error loading shared library %s: %m (needed by %s)",
 657                                         p->strings + p->dynv[i+1], p->name);
 658                                 if (runtime) longjmp(*rtld_fail, 1);
 659                                 dprintf(2, "%s\n", errbuf);
 660                                 ldso_fail = 1;
 661                                 continue;
 662                         }
 663                         if (runtime) {
 664                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 665                                 if (!tmp) longjmp(*rtld_fail, 1);
 666                                 tmp[ndeps++] = dep;
 667                                 tmp[ndeps] = 0;
 668                                 *deps = tmp;
 669                         }
 670                 }
 671         }
 672 }
 673
 674 static void load_preload(char *s)
 675 {
 676         int tmp;
 677         char *z;
 678         for (z=s; *z; s=z) {
 679                 for (   ; *s && isspace(*s); s++);
 680                 for (z=s; *z && !isspace(*z); z++);
 681                 tmp = *z;
 682                 *z = 0;
 683                 load_library(s, 0);
 684                 *z = tmp;
 685         }
 686 }
 687
 688 static void make_global(struct dso *p)
 689 {
 690         for (; p; p=p->next) p->global = 1;
 691 }
 692
 693 static void reloc_all(struct dso *p)
 694 {
 695         size_t dyn[DYN_CNT] = {0};
 696         for (; p; p=p->next) {
 697                 if (p->relocated) continue;
 698                 decode_vec(p->dynv, dyn, DYN_CNT);
 699 #ifdef NEED_ARCH_RELOCS
 700                 do_arch_relocs(p, head);
 701 #endif
 702                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 703                         2+(dyn[DT_PLTREL]==DT_RELA));
 704                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 705                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 706                 p->relocated = 1;
 707         }
 708 }
 709
 710 static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
 711 {
 712         for (; cnt--; ph = (void *)((char *)ph + stride))
 713                 if (ph->p_type == PT_DYNAMIC)
 714                         return ph->p_vaddr;
 715         return 0;
 716 }
 717
 718 static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p)
 719 {
 720         size_t min_addr = -1, max_addr = 0;
 721         for (; cnt--; ph = (void *)((char *)ph + stride)) {
 722                 if (ph->p_type != PT_LOAD) continue;
 723                 if (ph->p_vaddr < min_addr)
 724                         min_addr = ph->p_vaddr;
 725                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 726                         max_addr = ph->p_vaddr+ph->p_memsz;
 727         }
 728         min_addr &= -PAGE_SIZE;
 729         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 730         p->map = p->base + min_addr;
 731         p->map_len = max_addr - min_addr;
 732 }
 733
 734 static void do_fini()
 735 {
 736         struct dso *p;
 737         size_t dyn[DYN_CNT] = {0};
 738         for (p=fini_head; p; p=p->fini_next) {
 739                 if (!p->constructed) continue;
 740                 decode_vec(p->dynv, dyn, DYN_CNT);
 741                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
 742                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
 743                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
 744                         while (n--) ((void (*)(void))*--fn)();
 745                 }
 746 #ifndef NO_LEGACY_INITFINI
 747                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 748                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
 749 #endif
 750         }
 751 }
 752
 753 static void do_init_fini(struct dso *p)
 754 {
 755         size_t dyn[DYN_CNT] = {0};
 756         int need_locking = libc.threads_minus_1;
 757         /* Allow recursive calls that arise when a library calls
 758          * dlopen from one of its constructors, but block any
 759          * other threads until all ctors have finished. */
 760         if (need_locking) pthread_mutex_lock(&init_fini_lock);
 761         for (; p; p=p->prev) {
 762                 if (p->constructed) continue;
 763                 p->constructed = 1;
 764                 decode_vec(p->dynv, dyn, DYN_CNT);
 765                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
 766                         p->fini_next = fini_head;
 767                         fini_head = p;
 768                 }
 769 #ifndef NO_LEGACY_INITFINI
 770                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 771                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
 772 #endif
 773                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
 774                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
 775                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
 776                         while (n--) ((void (*)(void))*fn++)();
 777                 }
 778                 if (!need_locking && libc.threads_minus_1) {
 779                         need_locking = 1;
 780                         pthread_mutex_lock(&init_fini_lock);
 781                 }
 782         }
 783         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 784 }
 785
 786 void _dl_debug_state(void)
 787 {
 788 }
 789
 790 void __reset_tls()
 791 {
 792         pthread_t self = __pthread_self();
 793         struct dso *p;
 794         for (p=head; p; p=p->next) {
 795                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
 796                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
 797                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
 798                         p->tls_size - p->tls_len);
 799                 if (p->tls_id == (size_t)self->dtv[0]) break;
 800         }
 801 }
 802
 803 void *__copy_tls(unsigned char *mem)
 804 {
 805         pthread_t td;
 806         struct dso *p;
 807
 808         if (!tls_cnt) return mem;
 809
 810         void **dtv = (void *)mem;
 811         dtv[0] = (void *)tls_cnt;
 812
 813 #ifdef TLS_ABOVE_TP
 814         mem += sizeof(void *) * (tls_cnt+1);
 815         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
 816         td = (pthread_t)mem;
 817         mem += sizeof(struct pthread);
 818
 819         for (p=head; p; p=p->next) {
 820                 if (!p->tls_id) continue;
 821                 dtv[p->tls_id] = mem + p->tls_offset;
 822                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 823         }
 824 #else
 825         mem += libc.tls_size - sizeof(struct pthread);
 826         mem -= (uintptr_t)mem & (tls_align-1);
 827         td = (pthread_t)mem;
 828
 829         for (p=head; p; p=p->next) {
 830                 if (!p->tls_id) continue;
 831                 dtv[p->tls_id] = mem - p->tls_offset;
 832                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 833         }
 834 #endif
 835         td->dtv = dtv;
 836         return td;
 837 }
 838
 839 void *__tls_get_addr(size_t *v)
 840 {
 841         pthread_t self = __pthread_self();
 842         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
 843                 return (char *)self->dtv[v[0]]+v[1];
 844
 845         /* Block signals to make accessing new TLS async-signal-safe */
 846         sigset_t set;
 847         pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
 848         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
 849                 pthread_sigmask(SIG_SETMASK, &set, 0);
 850                 return (char *)self->dtv[v[0]]+v[1];
 851         }
 852
 853         /* This is safe without any locks held because, if the caller
 854          * is able to request the Nth entry of the DTV, the DSO list
 855          * must be valid at least that far out and it was synchronized
 856          * at program startup or by an already-completed call to dlopen. */
 857         struct dso *p;
 858         for (p=head; p->tls_id != v[0]; p=p->next);
 859
 860         /* Get new DTV space from new DSO if needed */
 861         if (v[0] > (size_t)self->dtv[0]) {
 862                 void **newdtv = p->new_dtv +
 863                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
 864                 memcpy(newdtv, self->dtv,
 865                         ((size_t)self->dtv[0]+1) * sizeof(void *));
 866                 newdtv[0] = (void *)v[0];
 867                 self->dtv = newdtv;
 868         }
 869
 870         /* Get new TLS memory from new DSO */
 871         unsigned char *mem = p->new_tls +
 872                 (p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1);
 873         mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1);
 874         self->dtv[v[0]] = mem;
 875         memcpy(mem, p->tls_image, p->tls_len);
 876         pthread_sigmask(SIG_SETMASK, &set, 0);
 877         return mem + v[1];
 878 }
 879
 880 static void update_tls_size()
 881 {
 882         libc.tls_size = ALIGN(
 883                 (1+tls_cnt) * sizeof(void *) +
 884                 tls_offset +
 885                 sizeof(struct pthread) +
 886                 tls_align * 2,
 887         tls_align);
 888 }
 889
 890 void *__dynlink(int argc, char **argv)
 891 {
 892         size_t aux[AUX_CNT] = {0};
 893         size_t i;
 894         Phdr *phdr;
 895         Ehdr *ehdr;
 896         static struct dso builtin_dsos[3];
 897         struct dso *const app = builtin_dsos+0;
 898         struct dso *const lib = builtin_dsos+1;
 899         struct dso *const vdso = builtin_dsos+2;
 900         char *env_preload=0;
 901         size_t vdso_base;
 902         size_t *auxv;
 903         char **envp = argv+argc+1;
 904
 905         /* Find aux vector just past environ[] */
 906         for (i=argc+1; argv[i]; i++)
 907                 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
 908                         env_path = argv[i]+16;
 909                 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
 910                         env_preload = argv[i]+11;
 911         auxv = (void *)(argv+i+1);
 912
 913         decode_vec(auxv, aux, AUX_CNT);
 914
 915         /* Only trust user/env if kernel says we're not suid/sgid */
 916         if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
 917           || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
 918                 env_path = 0;
 919                 env_preload = 0;
 920         }
 921
 922         /* If the dynamic linker was invoked as a program itself, AT_BASE
 923          * will not be set. In that case, we assume the base address is
 924          * the start of the page containing the PHDRs; I don't know any
 925          * better approach... */
 926         if (!aux[AT_BASE]) {
 927                 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
 928                 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
 929         }
 930
 931         /* The dynamic linker load address is passed by the kernel
 932          * in the AUX vector, so this is easy. */
 933         lib->base = (void *)aux[AT_BASE];
 934         lib->name = lib->shortname = "libc.so";
 935         lib->global = 1;
 936         ehdr = (void *)lib->base;
 937         lib->phnum = ehdr->e_phnum;
 938         lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
 939         find_map_range(lib->phdr, ehdr->e_phnum, ehdr->e_phentsize, lib);
 940         lib->dynv = (void *)(lib->base + find_dyn(lib->phdr,
 941                 ehdr->e_phnum, ehdr->e_phentsize));
 942         decode_dyn(lib);
 943
 944         if (aux[AT_PHDR]) {
 945                 size_t interp_off = 0;
 946                 size_t tls_image = 0;
 947                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
 948                 app->phdr = phdr = (void *)aux[AT_PHDR];
 949                 app->phnum = aux[AT_PHNUM];
 950                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
 951                         if (phdr->p_type == PT_PHDR)
 952                                 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
 953                         else if (phdr->p_type == PT_INTERP)
 954                                 interp_off = (size_t)phdr->p_vaddr;
 955                         else if (phdr->p_type == PT_TLS) {
 956                                 tls_image = phdr->p_vaddr;
 957                                 app->tls_len = phdr->p_filesz;
 958                                 app->tls_size = phdr->p_memsz;
 959                                 app->tls_align = phdr->p_align;
 960                         }
 961                 }
 962                 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
 963                 if (interp_off) lib->name = (char *)app->base + interp_off;
 964                 app->name = argv[0];
 965                 app->dynv = (void *)(app->base + find_dyn(
 966                         (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
 967                 find_map_range((void *)aux[AT_PHDR],
 968                         aux[AT_PHNUM], aux[AT_PHENT], app);
 969         } else {
 970                 int fd;
 971                 char *ldname = argv[0];
 972                 size_t l = strlen(ldname);
 973                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
 974                 *argv++ = (void *)-1;
 975                 if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
 976                 if (!argv[0]) {
 977                         dprintf(2, "musl libc/dynamic program loader\n");
 978                         dprintf(2, "usage: %s pathname%s\n", ldname,
 979                                 ldd_mode ? "" : " [args]");
 980                         _exit(1);
 981                 }
 982                 fd = open(argv[0], O_RDONLY);
 983                 if (fd < 0) {
 984                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
 985                         _exit(1);
 986                 }
 987                 runtime = 1;
 988                 ehdr = (void *)map_library(fd, app);
 989                 if (!ehdr) {
 990                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
 991                         _exit(1);
 992                 }
 993                 runtime = 0;
 994                 close(fd);
 995                 lib->name = ldname;
 996                 app->name = argv[0];
 997                 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
 998                 /* Find the name that would have been used for the dynamic
 999                  * linker had ldd not taken its place. */
1000                 if (ldd_mode) {
1001                         for (i=0; i<app->phnum; i++) {
1002                                 if (app->phdr[i].p_type == PT_INTERP)
1003                                         lib->name = (void *)(app->base
1004                                                 + app->phdr[i].p_vaddr);
1005                         }
1006                         dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
1007                 }
1008         }
1009         if (app->tls_size) {
1010                 app->tls_id = tls_cnt = 1;
1011 #ifdef TLS_ABOVE_TP
1012                 app->tls_offset = 0;
1013                 tls_offset = app->tls_size
1014                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1015                         & (app->tls_align-1) );
1016 #else
1017                 tls_offset = app->tls_offset = app->tls_size
1018                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1019                         & (app->tls_align-1) );
1020 #endif
1021                 tls_align = MAXP2(tls_align, app->tls_align);
1022         }
1023         app->global = 1;
1024         decode_dyn(app);
1025
1026         /* Attach to vdso, if provided by the kernel */
1027         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1028                 ehdr = (void *)vdso_base;
1029                 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1030                 vdso->phnum = ehdr->e_phnum;
1031                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1032                         if (phdr->p_type == PT_DYNAMIC)
1033                                 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1034                         if (phdr->p_type == PT_LOAD)
1035                                 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1036                 }
1037                 vdso->name = "";
1038                 vdso->shortname = "linux-gate.so.1";
1039                 vdso->global = 1;
1040                 decode_dyn(vdso);
1041                 vdso->prev = lib;
1042                 lib->next = vdso;
1043         }
1044
1045         /* Initial dso chain consists only of the app. We temporarily
1046          * append the dynamic linker/libc so we can relocate it, then
1047          * restore the initial chain in preparation for loading third
1048          * party libraries (preload/needed). */
1049         head = tail = app;
1050         ldso = lib;
1051         app->next = lib;
1052         reloc_all(lib);
1053         app->next = 0;
1054
1055         /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1056
1057         /* Donate unused parts of app and library mapping to malloc */
1058         reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
1059         ehdr = (void *)lib->base;
1060         reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
1061                 ehdr->e_phentsize, ehdr->e_phnum);
1062
1063         /* Load preload/needed libraries, add their symbols to the global
1064          * namespace, and perform all remaining relocations. The main
1065          * program must be relocated LAST since it may contain copy
1066          * relocations which depend on libraries' relocations. */
1067         if (env_preload) load_preload(env_preload);
1068         load_deps(app);
1069         make_global(app);
1070
1071         reloc_all(app->next);
1072         reloc_all(app);
1073
1074         update_tls_size();
1075         if (tls_cnt) {
1076                 void *mem = mmap(0, libc.tls_size, PROT_READ|PROT_WRITE,
1077                         MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1078                 if (mem==MAP_FAILED ||
1079                     !__install_initial_tls(__copy_tls(mem))) {
1080                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1081                                 argv[0], libc.tls_size);
1082                         _exit(127);
1083                 }
1084         }
1085
1086         if (ldso_fail) _exit(127);
1087         if (ldd_mode) _exit(0);
1088
1089         /* Switch to runtime mode: any further failures in the dynamic
1090          * linker are a reportable failure rather than a fatal startup
1091          * error. If the dynamic loader (dlopen) will not be used, free
1092          * all memory used by the dynamic linker. */
1093         runtime = 1;
1094
1095 #ifndef DYNAMIC_IS_RO
1096         for (i=0; app->dynv[i]; i+=2)
1097                 if (app->dynv[i]==DT_DEBUG)
1098                         app->dynv[i+1] = (size_t)&debug;
1099 #endif
1100         debug.ver = 1;
1101         debug.bp = _dl_debug_state;
1102         debug.head = head;
1103         debug.base = lib->base;
1104         debug.state = 0;
1105         _dl_debug_state();
1106
1107         if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]);
1108         __init_libc(envp, argv[0]);
1109         atexit(do_fini);
1110         errno = 0;
1111         do_init_fini(tail);
1112
1113         return (void *)aux[AT_ENTRY];
1114 }
1115
1116 void *dlopen(const char *file, int mode)
1117 {
1118         struct dso *volatile p, *orig_tail, *next;
1119         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1120         size_t i;
1121         int cs;
1122         jmp_buf jb;
1123
1124         if (!file) return head;
1125
1126         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1127         pthread_rwlock_wrlock(&lock);
1128         __inhibit_ptc();
1129
1130         p = 0;
1131         orig_tls_cnt = tls_cnt;
1132         orig_tls_offset = tls_offset;
1133         orig_tls_align = tls_align;
1134         orig_tail = tail;
1135         noload = mode & RTLD_NOLOAD;
1136
1137         rtld_fail = &jb;
1138         if (setjmp(*rtld_fail)) {
1139                 /* Clean up anything new that was (partially) loaded */
1140                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1141                         if (p->deps[i]->global < 0)
1142                                 p->deps[i]->global = 0;
1143                 for (p=orig_tail->next; p; p=next) {
1144                         next = p->next;
1145                         munmap(p->map, p->map_len);
1146                         free(p->deps);
1147                         free(p);
1148                 }
1149                 tls_cnt = orig_tls_cnt;
1150                 tls_offset = orig_tls_offset;
1151                 tls_align = orig_tls_align;
1152                 tail = orig_tail;
1153                 tail->next = 0;
1154                 p = 0;
1155                 errflag = 1;
1156                 goto end;
1157         } else p = load_library(file, 0);
1158
1159         if (!p) {
1160                 snprintf(errbuf, sizeof errbuf, noload ?
1161                         "Library %s is not already loaded" :
1162                         "Error loading shared library %s: %m",
1163                         file);
1164                 errflag = 1;
1165                 goto end;
1166         }
1167
1168         /* First load handling */
1169         if (!p->deps) {
1170                 load_deps(p);
1171                 if (p->deps) for (i=0; p->deps[i]; i++)
1172                         if (!p->deps[i]->global)
1173                                 p->deps[i]->global = -1;
1174                 if (!p->global) p->global = -1;
1175                 reloc_all(p);
1176                 if (p->deps) for (i=0; p->deps[i]; i++)
1177                         if (p->deps[i]->global < 0)
1178                                 p->deps[i]->global = 0;
1179                 if (p->global < 0) p->global = 0;
1180         }
1181
1182         if (mode & RTLD_GLOBAL) {
1183                 if (p->deps) for (i=0; p->deps[i]; i++)
1184                         p->deps[i]->global = 1;
1185                 p->global = 1;
1186         }
1187
1188         update_tls_size();
1189
1190         if (ssp_used) __init_ssp(libc.auxv);
1191
1192         _dl_debug_state();
1193         orig_tail = tail;
1194 end:
1195         __release_ptc();
1196         if (p) gencnt++;
1197         pthread_rwlock_unlock(&lock);
1198         if (p) do_init_fini(orig_tail);
1199         pthread_setcancelstate(cs, 0);
1200         return p;
1201 }
1202
1203 static int invalid_dso_handle(void *h)
1204 {
1205         struct dso *p;
1206         for (p=head; p; p=p->next) if (h==p) return 0;
1207         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1208         errflag = 1;
1209         return 1;
1210 }
1211
1212 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1213 {
1214         size_t i;
1215         uint32_t h = 0, gh = 0;
1216         Sym *sym;
1217         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1218                 if (p == RTLD_DEFAULT) {
1219                         p = head;
1220                 } else if (p == RTLD_NEXT) {
1221                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1222                         if (!p) p=head;
1223                         p = p->next;
1224                 }
1225                 struct symdef def = find_sym(p, s, 0);
1226                 if (!def.sym) goto failed;
1227                 if ((def.sym->st_info&0xf) == STT_TLS)
1228                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1229                 return def.dso->base + def.sym->st_value;
1230         }
1231         if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1232                 return 0;
1233         if (p->ghashtab) {
1234                 gh = gnu_hash(s);
1235                 sym = gnu_lookup(s, gh, p);
1236         } else {
1237                 h = sysv_hash(s);
1238                 sym = sysv_lookup(s, h, p);
1239         }
1240         if (sym && (sym->st_info&0xf) == STT_TLS)
1241                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1242         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1243                 return p->base + sym->st_value;
1244         if (p->deps) for (i=0; p->deps[i]; i++) {
1245                 if (p->deps[i]->ghashtab) {
1246                         if (!gh) gh = gnu_hash(s);
1247                         sym = gnu_lookup(s, gh, p->deps[i]);
1248                 } else {
1249                         if (!h) h = sysv_hash(s);
1250                         sym = sysv_lookup(s, h, p->deps[i]);
1251                 }
1252                 if (sym && (sym->st_info&0xf) == STT_TLS)
1253                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1254                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1255                         return p->deps[i]->base + sym->st_value;
1256         }
1257 failed:
1258         errflag = 1;
1259         snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1260         return 0;
1261 }
1262
1263 int __dladdr(void *addr, Dl_info *info)
1264 {
1265         struct dso *p;
1266         Sym *sym;
1267         uint32_t nsym;
1268         char *strings;
1269         size_t i;
1270         void *best = 0;
1271         char *bestname;
1272
1273         pthread_rwlock_rdlock(&lock);
1274         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1275         pthread_rwlock_unlock(&lock);
1276
1277         if (!p) return 0;
1278
1279         sym = p->syms;
1280         strings = p->strings;
1281         if (p->hashtab) {
1282                 nsym = p->hashtab[1];
1283         } else {
1284                 uint32_t *buckets;
1285                 uint32_t *hashval;
1286                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1287                 sym += p->ghashtab[1];
1288                 for (i = 0; i < p->ghashtab[0]; i++) {
1289                         if (buckets[i] > nsym)
1290                                 nsym = buckets[i];
1291                 }
1292                 if (nsym) {
1293                         nsym -= p->ghashtab[1];
1294                         hashval = buckets + p->ghashtab[0] + nsym;
1295                         do nsym++;
1296                         while (!(*hashval++ & 1));
1297                 }
1298         }
1299
1300         for (; nsym; nsym--, sym++) {
1301                 if (sym->st_value
1302                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1303                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1304                         void *symaddr = p->base + sym->st_value;
1305                         if (symaddr > addr || symaddr < best)
1306                                 continue;
1307                         best = symaddr;
1308                         bestname = strings + sym->st_name;
1309                         if (addr == symaddr)
1310                                 break;
1311                 }
1312         }
1313
1314         if (!best) return 0;
1315
1316         info->dli_fname = p->name;
1317         info->dli_fbase = p->base;
1318         info->dli_sname = bestname;
1319         info->dli_saddr = best;
1320
1321         return 1;
1322 }
1323
1324 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1325 {
1326         void *res;
1327         pthread_rwlock_rdlock(&lock);
1328         res = do_dlsym(p, s, ra);
1329         pthread_rwlock_unlock(&lock);
1330         return res;
1331 }
1332
1333 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1334 {
1335         struct dso *current;
1336         struct dl_phdr_info info;
1337         int ret = 0;
1338         for(current = head; current;) {
1339                 info.dlpi_addr      = (uintptr_t)current->base;
1340                 info.dlpi_name      = current->name;
1341                 info.dlpi_phdr      = current->phdr;
1342                 info.dlpi_phnum     = current->phnum;
1343                 info.dlpi_adds      = gencnt;
1344                 info.dlpi_subs      = 0;
1345                 info.dlpi_tls_modid = current->tls_id;
1346                 info.dlpi_tls_data  = current->tls_image;
1347
1348                 ret = (callback)(&info, sizeof (info), data);
1349
1350                 if (ret != 0) break;
1351
1352                 pthread_rwlock_rdlock(&lock);
1353                 current = current->next;
1354                 pthread_rwlock_unlock(&lock);
1355         }
1356         return ret;
1357 }
1358 #else
1359 static int invalid_dso_handle(void *h)
1360 {
1361         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1362         errflag = 1;
1363         return 1;
1364 }
1365 void *dlopen(const char *file, int mode)
1366 {
1367         return 0;
1368 }
1369 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1370 {
1371         return 0;
1372 }
1373 int __dladdr (void *addr, Dl_info *info)
1374 {
1375         return 0;
1376 }
1377 #endif
1378
1379 int __dlinfo(void *dso, int req, void *res)
1380 {
1381         if (invalid_dso_handle(dso)) return -1;
1382         if (req != RTLD_DI_LINKMAP) {
1383                 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1384                 errflag = 1;
1385                 return -1;
1386         }
1387         *(struct link_map **)res = dso;
1388         return 0;
1389 }
1390
1391 char *dlerror()
1392 {
1393         if (!errflag) return 0;
1394         errflag = 0;
1395         return errbuf;
1396 }
1397
1398 int dlclose(void *p)
1399 {
1400         return invalid_dso_handle(p);
1401 }