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