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move static-linked stub invalid dso handle checking out of dynlink.c
[musl.git] / src / ldso / dynlink.c
blob4f857e5ac0144777d39021941bd6f1faaa4d0a17
1 #define _GNU_SOURCE
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <stdarg.h>
5 #include <stddef.h>
6 #include <string.h>
7 #include <unistd.h>
8 #include <stdint.h>
9 #include <elf.h>
10 #include <sys/mman.h>
11 #include <limits.h>
12 #include <fcntl.h>
13 #include <sys/stat.h>
14 #include <errno.h>
15 #include <link.h>
16 #include <setjmp.h>
17 #include <pthread.h>
18 #include <ctype.h>
19 #include <dlfcn.h>
20 #include "pthread_impl.h"
21 #include "libc.h"
22 #include "dynlink.h"
23
24 static void error(const char *, ...);
25
26 #ifdef SHARED
27
28 #define MAXP2(a,b) (-(-(a)&-(b)))
29 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
30
31 struct debug {
32 int ver;
33 void *head;
34 void (*bp)(void);
35 int state;
36 void *base;
37 };
38
39 struct td_index {
40 size_t args[2];
41 struct td_index *next;
42 };
43
44 struct dso {
45 #if DL_FDPIC
46 struct fdpic_loadmap *loadmap;
47 #else
48 unsigned char *base;
49 #endif
50 char *name;
51 size_t *dynv;
52 struct dso *next, *prev;
53
54 Phdr *phdr;
55 int phnum;
56 size_t phentsize;
57 int refcnt;
58 Sym *syms;
59 uint32_t *hashtab;
60 uint32_t *ghashtab;
61 int16_t *versym;
62 char *strings;
63 unsigned char *map;
64 size_t map_len;
65 dev_t dev;
66 ino_t ino;
67 signed char global;
68 char relocated;
69 char constructed;
70 char kernel_mapped;
71 struct dso **deps, *needed_by;
72 char *rpath_orig, *rpath;
73 struct tls_module tls;
74 size_t tls_id;
75 size_t relro_start, relro_end;
76 void **new_dtv;
77 unsigned char *new_tls;
78 volatile int new_dtv_idx, new_tls_idx;
79 struct td_index *td_index;
80 struct dso *fini_next;
81 char *shortname;
82 #if DL_FDPIC
83 unsigned char *base;
84 #else
85 struct fdpic_loadmap *loadmap;
86 #endif
87 struct funcdesc {
88 void *addr;
89 size_t *got;
90 } *funcdescs;
91 size_t *got;
92 char buf[];
93 };
94
95 struct symdef {
96 Sym *sym;
97 struct dso *dso;
98 };
99
100 int __init_tp(void *);
101 void __init_libc(char **, char *);
102 void *__copy_tls(unsigned char *);
103
104 __attribute__((__visibility__("hidden")))
105 const char *__libc_get_version(void);
106
107 static struct builtin_tls {
108 char c;
109 struct pthread pt;
110 void *space[16];
111 } builtin_tls[1];
112 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
113
114 #define ADDEND_LIMIT 4096
115 static size_t *saved_addends, *apply_addends_to;
116
117 static struct dso ldso;
118 static struct dso *head, *tail, *fini_head;
119 static char *env_path, *sys_path;
120 static unsigned long long gencnt;
121 static int runtime;
122 static int ldd_mode;
123 static int ldso_fail;
124 static int noload;
125 static jmp_buf *rtld_fail;
126 static pthread_rwlock_t lock;
127 static struct debug debug;
128 static struct tls_module *tls_tail;
129 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
130 static size_t static_tls_cnt;
131 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
132 static struct fdpic_loadmap *app_loadmap;
133 static struct fdpic_dummy_loadmap app_dummy_loadmap;
134
135 struct debug *_dl_debug_addr = &debug;
136
137 __attribute__((__visibility__("hidden")))
138 void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
139
140 __attribute__((__visibility__("hidden")))
141 extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
142
143 weak_alias(__init_array_start, __init_array_end);
144 weak_alias(__fini_array_start, __fini_array_end);
145
146 static int dl_strcmp(const char *l, const char *r)
147 {
148 for (; *l==*r && *l; l++, r++);
149 return *(unsigned char *)l - *(unsigned char *)r;
150 }
151 #define strcmp(l,r) dl_strcmp(l,r)
152
153 /* Compute load address for a virtual address in a given dso. */
154 #if DL_FDPIC
155 static void *laddr(const struct dso *p, size_t v)
156 {
157 size_t j=0;
158 if (!p->loadmap) return p->base + v;
159 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
160 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
161 }
162 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
163 laddr(p, v), (p)->got })
164 #else
165 #define laddr(p, v) (void *)((p)->base + (v))
166 #define fpaddr(p, v) ((void (*)())laddr(p, v))
167 #endif
168
169 static void decode_vec(size_t *v, size_t *a, size_t cnt)
170 {
171 size_t i;
172 for (i=0; i<cnt; i++) a[i] = 0;
173 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
174 a[0] |= 1UL<<v[0];
175 a[v[0]] = v[1];
176 }
177 }
178
179 static int search_vec(size_t *v, size_t *r, size_t key)
180 {
181 for (; v[0]!=key; v+=2)
182 if (!v[0]) return 0;
183 *r = v[1];
184 return 1;
185 }
186
187 static uint32_t sysv_hash(const char *s0)
188 {
189 const unsigned char *s = (void *)s0;
190 uint_fast32_t h = 0;
191 while (*s) {
192 h = 16*h + *s++;
193 h ^= h>>24 & 0xf0;
194 }
195 return h & 0xfffffff;
196 }
197
198 static uint32_t gnu_hash(const char *s0)
199 {
200 const unsigned char *s = (void *)s0;
201 uint_fast32_t h = 5381;
202 for (; *s; s++)
203 h += h*32 + *s;
204 return h;
205 }
206
207 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
208 {
209 size_t i;
210 Sym *syms = dso->syms;
211 uint32_t *hashtab = dso->hashtab;
212 char *strings = dso->strings;
213 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
214 if ((!dso->versym || dso->versym[i] >= 0)
215 && (!strcmp(s, strings+syms[i].st_name)))
216 return syms+i;
217 }
218 return 0;
219 }
220
221 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
222 {
223 uint32_t nbuckets = hashtab[0];
224 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
225 uint32_t i = buckets[h1 % nbuckets];
226
227 if (!i) return 0;
228
229 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
230
231 for (h1 |= 1; ; i++) {
232 uint32_t h2 = *hashval++;
233 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
234 && !strcmp(s, dso->strings + dso->syms[i].st_name))
235 return dso->syms+i;
236 if (h2 & 1) break;
237 }
238
239 return 0;
240 }
241
242 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
243 {
244 const size_t *bloomwords = (const void *)(hashtab+4);
245 size_t f = bloomwords[fofs & (hashtab[2]-1)];
246 if (!(f & fmask)) return 0;
247
248 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
249 if (!(f & 1)) return 0;
250
251 return gnu_lookup(h1, hashtab, dso, s);
252 }
253
254 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
255 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
256
257 #ifndef ARCH_SYM_REJECT_UND
258 #define ARCH_SYM_REJECT_UND(s) 0
259 #endif
260
261 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
262 {
263 uint32_t h = 0, gh, gho, *ght;
264 size_t ghm = 0;
265 struct symdef def = {0};
266 for (; dso; dso=dso->next) {
267 Sym *sym;
268 if (!dso->global) continue;
269 if ((ght = dso->ghashtab)) {
270 if (!ghm) {
271 gh = gnu_hash(s);
272 int maskbits = 8 * sizeof ghm;
273 gho = gh / maskbits;
274 ghm = 1ul << gh % maskbits;
275 }
276 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
277 } else {
278 if (!h) h = sysv_hash(s);
279 sym = sysv_lookup(s, h, dso);
280 }
281 if (!sym) continue;
282 if (!sym->st_shndx)
283 if (need_def || (sym->st_info&0xf) == STT_TLS
284 || ARCH_SYM_REJECT_UND(sym))
285 continue;
286 if (!sym->st_value)
287 if ((sym->st_info&0xf) != STT_TLS)
288 continue;
289 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
290 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
291
292 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
293 def.sym = sym;
294 def.dso = dso;
295 if (sym->st_info>>4 == STB_GLOBAL) break;
296 }
297 return def;
298 }
299
300 __attribute__((__visibility__("hidden")))
301 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
302
303 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
304 {
305 unsigned char *base = dso->base;
306 Sym *syms = dso->syms;
307 char *strings = dso->strings;
308 Sym *sym;
309 const char *name;
310 void *ctx;
311 int type;
312 int sym_index;
313 struct symdef def;
314 size_t *reloc_addr;
315 size_t sym_val;
316 size_t tls_val;
317 size_t addend;
318 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
319
320 if (dso == &ldso) {
321 /* Only ldso's REL table needs addend saving/reuse. */
322 if (rel == apply_addends_to)
323 reuse_addends = 1;
324 skip_relative = 1;
325 }
326
327 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
328 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
329 type = R_TYPE(rel[1]);
330 if (type == REL_NONE) continue;
331 sym_index = R_SYM(rel[1]);
332 reloc_addr = laddr(dso, rel[0]);
333 if (sym_index) {
334 sym = syms + sym_index;
335 name = strings + sym->st_name;
336 ctx = type==REL_COPY ? head->next : head;
337 def = (sym->st_info&0xf) == STT_SECTION
338 ? (struct symdef){ .dso = dso, .sym = sym }
339 : find_sym(ctx, name, type==REL_PLT);
340 if (!def.sym && (sym->st_shndx != SHN_UNDEF
341 || sym->st_info>>4 != STB_WEAK)) {
342 error("Error relocating %s: %s: symbol not found",
343 dso->name, name);
344 if (runtime) longjmp(*rtld_fail, 1);
345 continue;
346 }
347 } else {
348 sym = 0;
349 def.sym = 0;
350 def.dso = dso;
351 }
352
353 if (stride > 2) {
354 addend = rel[2];
355 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
356 addend = 0;
357 } else if (reuse_addends) {
358 /* Save original addend in stage 2 where the dso
359 * chain consists of just ldso; otherwise read back
360 * saved addend since the inline one was clobbered. */
361 if (head==&ldso)
362 saved_addends[save_slot] = *reloc_addr;
363 addend = saved_addends[save_slot++];
364 } else {
365 addend = *reloc_addr;
366 }
367
368 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
369 tls_val = def.sym ? def.sym->st_value : 0;
370
371 switch(type) {
372 case REL_NONE:
373 break;
374 case REL_OFFSET:
375 addend -= (size_t)reloc_addr;
376 case REL_SYMBOLIC:
377 case REL_GOT:
378 case REL_PLT:
379 *reloc_addr = sym_val + addend;
380 break;
381 case REL_RELATIVE:
382 *reloc_addr = (size_t)base + addend;
383 break;
384 case REL_SYM_OR_REL:
385 if (sym) *reloc_addr = sym_val + addend;
386 else *reloc_addr = (size_t)base + addend;
387 break;
388 case REL_COPY:
389 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
390 break;
391 case REL_OFFSET32:
392 *(uint32_t *)reloc_addr = sym_val + addend
393 - (size_t)reloc_addr;
394 break;
395 case REL_FUNCDESC:
396 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
397 + (def.sym - def.dso->syms)) : 0;
398 break;
399 case REL_FUNCDESC_VAL:
400 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
401 else *reloc_addr = sym_val;
402 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
403 break;
404 case REL_DTPMOD:
405 *reloc_addr = def.dso->tls_id;
406 break;
407 case REL_DTPOFF:
408 *reloc_addr = tls_val + addend - DTP_OFFSET;
409 break;
410 #ifdef TLS_ABOVE_TP
411 case REL_TPOFF:
412 *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
413 break;
414 #else
415 case REL_TPOFF:
416 *reloc_addr = tls_val - def.dso->tls.offset + addend;
417 break;
418 case REL_TPOFF_NEG:
419 *reloc_addr = def.dso->tls.offset - tls_val + addend;
420 break;
421 #endif
422 case REL_TLSDESC:
423 if (stride<3) addend = reloc_addr[1];
424 if (runtime && def.dso->tls_id >= static_tls_cnt) {
425 struct td_index *new = malloc(sizeof *new);
426 if (!new) {
427 error(
428 "Error relocating %s: cannot allocate TLSDESC for %s",
429 dso->name, sym ? name : "(local)" );
430 longjmp(*rtld_fail, 1);
431 }
432 new->next = dso->td_index;
433 dso->td_index = new;
434 new->args[0] = def.dso->tls_id;
435 new->args[1] = tls_val + addend;
436 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
437 reloc_addr[1] = (size_t)new;
438 } else {
439 reloc_addr[0] = (size_t)__tlsdesc_static;
440 #ifdef TLS_ABOVE_TP
441 reloc_addr[1] = tls_val + def.dso->tls.offset
442 + TPOFF_K + addend;
443 #else
444 reloc_addr[1] = tls_val - def.dso->tls.offset
445 + addend;
446 #endif
447 }
448 break;
449 default:
450 error("Error relocating %s: unsupported relocation type %d",
451 dso->name, type);
452 if (runtime) longjmp(*rtld_fail, 1);
453 continue;
454 }
455 }
456 }
457
458 /* A huge hack: to make up for the wastefulness of shared libraries
459 * needing at least a page of dirty memory even if they have no global
460 * data, we reclaim the gaps at the beginning and end of writable maps
461 * and "donate" them to the heap by setting up minimal malloc
462 * structures and then freeing them. */
463
464 static void reclaim(struct dso *dso, size_t start, size_t end)
465 {
466 size_t *a, *z;
467 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
468 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
469 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
470 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
471 if (start>end || end-start < 4*sizeof(size_t)) return;
472 a = laddr(dso, start);
473 z = laddr(dso, end);
474 a[-2] = 1;
475 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
476 z[1] = 1;
477 free(a);
478 }
479
480 static void reclaim_gaps(struct dso *dso)
481 {
482 Phdr *ph = dso->phdr;
483 size_t phcnt = dso->phnum;
484
485 if (DL_FDPIC) return; // FIXME
486 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
487 if (ph->p_type!=PT_LOAD) continue;
488 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
489 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
490 reclaim(dso, ph->p_vaddr+ph->p_memsz,
491 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
492 }
493 }
494
495 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
496 {
497 static int no_map_fixed;
498 char *q;
499 if (!no_map_fixed) {
500 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
501 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
502 return q;
503 no_map_fixed = 1;
504 }
505 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
506 if (flags & MAP_ANONYMOUS) {
507 memset(p, 0, n);
508 return p;
509 }
510 ssize_t r;
511 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
512 for (q=p; n; q+=r, off+=r, n-=r) {
513 r = read(fd, q, n);
514 if (r < 0 && errno != EINTR) return MAP_FAILED;
515 if (!r) {
516 memset(q, 0, n);
517 break;
518 }
519 }
520 return p;
521 }
522
523 static void unmap_library(struct dso *dso)
524 {
525 if (dso->loadmap) {
526 size_t i;
527 for (i=0; i<dso->loadmap->nsegs; i++) {
528 if (!dso->loadmap->segs[i].p_memsz)
529 continue;
530 munmap((void *)dso->loadmap->segs[i].addr,
531 dso->loadmap->segs[i].p_memsz);
532 }
533 free(dso->loadmap);
534 } else if (dso->map && dso->map_len) {
535 munmap(dso->map, dso->map_len);
536 }
537 }
538
539 static void *map_library(int fd, struct dso *dso)
540 {
541 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
542 void *allocated_buf=0;
543 size_t phsize;
544 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
545 size_t this_min, this_max;
546 size_t nsegs = 0;
547 off_t off_start;
548 Ehdr *eh;
549 Phdr *ph, *ph0;
550 unsigned prot;
551 unsigned char *map=MAP_FAILED, *base;
552 size_t dyn=0;
553 size_t tls_image=0;
554 size_t i;
555
556 ssize_t l = read(fd, buf, sizeof buf);
557 eh = buf;
558 if (l<0) return 0;
559 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
560 goto noexec;
561 phsize = eh->e_phentsize * eh->e_phnum;
562 if (phsize > sizeof buf - sizeof *eh) {
563 allocated_buf = malloc(phsize);
564 if (!allocated_buf) return 0;
565 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
566 if (l < 0) goto error;
567 if (l != phsize) goto noexec;
568 ph = ph0 = allocated_buf;
569 } else if (eh->e_phoff + phsize > l) {
570 l = pread(fd, buf+1, phsize, eh->e_phoff);
571 if (l < 0) goto error;
572 if (l != phsize) goto noexec;
573 ph = ph0 = (void *)(buf + 1);
574 } else {
575 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
576 }
577 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
578 if (ph->p_type == PT_DYNAMIC) {
579 dyn = ph->p_vaddr;
580 } else if (ph->p_type == PT_TLS) {
581 tls_image = ph->p_vaddr;
582 dso->tls.align = ph->p_align;
583 dso->tls.len = ph->p_filesz;
584 dso->tls.size = ph->p_memsz;
585 } else if (ph->p_type == PT_GNU_RELRO) {
586 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
587 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
588 }
589 if (ph->p_type != PT_LOAD) continue;
590 nsegs++;
591 if (ph->p_vaddr < addr_min) {
592 addr_min = ph->p_vaddr;
593 off_start = ph->p_offset;
594 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
595 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
596 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
597 }
598 if (ph->p_vaddr+ph->p_memsz > addr_max) {
599 addr_max = ph->p_vaddr+ph->p_memsz;
600 }
601 }
602 if (!dyn) goto noexec;
603 if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
604 dso->loadmap = calloc(1, sizeof *dso->loadmap
605 + nsegs * sizeof *dso->loadmap->segs);
606 if (!dso->loadmap) goto error;
607 dso->loadmap->nsegs = nsegs;
608 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
609 if (ph->p_type != PT_LOAD) continue;
610 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
611 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
612 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
613 map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
614 prot, MAP_PRIVATE,
615 fd, ph->p_offset & -PAGE_SIZE);
616 if (map == MAP_FAILED) {
617 unmap_library(dso);
618 goto error;
619 }
620 dso->loadmap->segs[i].addr = (size_t)map +
621 (ph->p_vaddr & PAGE_SIZE-1);
622 dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
623 dso->loadmap->segs[i].p_memsz = ph->p_memsz;
624 i++;
625 if (prot & PROT_WRITE) {
626 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
627 + ph->p_filesz;
628 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
629 size_t pgend = brk + ph->p_memsz - ph->p_filesz
630 + PAGE_SIZE-1 & -PAGE_SIZE;
631 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
632 pgend-pgbrk, prot,
633 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
634 -1, off_start) == MAP_FAILED)
635 goto error;
636 memset(map + brk, 0, pgbrk-brk);
637 }
638 }
639 map = (void *)dso->loadmap->segs[0].addr;
640 map_len = 0;
641 goto done_mapping;
642 }
643 addr_max += PAGE_SIZE-1;
644 addr_max &= -PAGE_SIZE;
645 addr_min &= -PAGE_SIZE;
646 off_start &= -PAGE_SIZE;
647 map_len = addr_max - addr_min + off_start;
648 /* The first time, we map too much, possibly even more than
649 * the length of the file. This is okay because we will not
650 * use the invalid part; we just need to reserve the right
651 * amount of virtual address space to map over later. */
652 map = DL_NOMMU_SUPPORT
653 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
654 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
655 : mmap((void *)addr_min, map_len, prot,
656 MAP_PRIVATE, fd, off_start);
657 if (map==MAP_FAILED) goto error;
658 dso->map = map;
659 dso->map_len = map_len;
660 /* If the loaded file is not relocatable and the requested address is
661 * not available, then the load operation must fail. */
662 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
663 errno = EBUSY;
664 goto error;
665 }
666 base = map - addr_min;
667 dso->phdr = 0;
668 dso->phnum = 0;
669 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
670 if (ph->p_type != PT_LOAD) continue;
671 /* Check if the programs headers are in this load segment, and
672 * if so, record the address for use by dl_iterate_phdr. */
673 if (!dso->phdr && eh->e_phoff >= ph->p_offset
674 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
675 dso->phdr = (void *)(base + ph->p_vaddr
676 + (eh->e_phoff-ph->p_offset));
677 dso->phnum = eh->e_phnum;
678 dso->phentsize = eh->e_phentsize;
679 }
680 /* Reuse the existing mapping for the lowest-address LOAD */
681 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
682 continue;
683 this_min = ph->p_vaddr & -PAGE_SIZE;
684 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
685 off_start = ph->p_offset & -PAGE_SIZE;
686 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
687 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
688 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
689 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
690 goto error;
691 if (ph->p_memsz > ph->p_filesz) {
692 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
693 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
694 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
695 if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
696 goto error;
697 }
698 }
699 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
700 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
701 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
702 && errno != ENOSYS)
703 goto error;
704 break;
705 }
706 done_mapping:
707 dso->base = base;
708 dso->dynv = laddr(dso, dyn);
709 if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
710 if (!runtime) reclaim_gaps(dso);
711 free(allocated_buf);
712 return map;
713 noexec:
714 errno = ENOEXEC;
715 error:
716 if (map!=MAP_FAILED) unmap_library(dso);
717 free(allocated_buf);
718 return 0;
719 }
720
721 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
722 {
723 size_t l;
724 int fd;
725 for (;;) {
726 s += strspn(s, ":\n");
727 l = strcspn(s, ":\n");
728 if (l-1 >= INT_MAX) return -1;
729 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
730 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
731 switch (errno) {
732 case ENOENT:
733 case ENOTDIR:
734 case EACCES:
735 case ENAMETOOLONG:
736 break;
737 default:
738 /* Any negative value but -1 will inhibit
739 * futher path search. */
740 return -2;
741 }
742 }
743 s += l;
744 }
745 }
746
747 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
748 {
749 size_t n, l;
750 const char *s, *t, *origin;
751 char *d;
752 if (p->rpath || !p->rpath_orig) return 0;
753 if (!strchr(p->rpath_orig, '$')) {
754 p->rpath = p->rpath_orig;
755 return 0;
756 }
757 n = 0;
758 s = p->rpath_orig;
759 while ((t=strchr(s, '$'))) {
760 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
761 return 0;
762 s = t+1;
763 n++;
764 }
765 if (n > SSIZE_MAX/PATH_MAX) return 0;
766
767 if (p->kernel_mapped) {
768 /* $ORIGIN searches cannot be performed for the main program
769 * when it is suid/sgid/AT_SECURE. This is because the
770 * pathname is under the control of the caller of execve.
771 * For libraries, however, $ORIGIN can be processed safely
772 * since the library's pathname came from a trusted source
773 * (either system paths or a call to dlopen). */
774 if (libc.secure)
775 return 0;
776 l = readlink("/proc/self/exe", buf, buf_size);
777 if (l == -1) switch (errno) {
778 case ENOENT:
779 case ENOTDIR:
780 case EACCES:
781 break;
782 default:
783 return -1;
784 }
785 if (l >= buf_size)
786 return 0;
787 buf[l] = 0;
788 origin = buf;
789 } else {
790 origin = p->name;
791 }
792 t = strrchr(origin, '/');
793 l = t ? t-origin : 0;
794 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
795 if (!p->rpath) return -1;
796
797 d = p->rpath;
798 s = p->rpath_orig;
799 while ((t=strchr(s, '$'))) {
800 memcpy(d, s, t-s);
801 d += t-s;
802 memcpy(d, origin, l);
803 d += l;
804 /* It was determined previously that the '$' is followed
805 * either by "ORIGIN" or "{ORIGIN}". */
806 s = t + 7 + 2*(t[1]=='{');
807 }
808 strcpy(d, s);
809 return 0;
810 }
811
812 static void decode_dyn(struct dso *p)
813 {
814 size_t dyn[DYN_CNT];
815 decode_vec(p->dynv, dyn, DYN_CNT);
816 p->syms = laddr(p, dyn[DT_SYMTAB]);
817 p->strings = laddr(p, dyn[DT_STRTAB]);
818 if (dyn[0]&(1<<DT_HASH))
819 p->hashtab = laddr(p, dyn[DT_HASH]);
820 if (dyn[0]&(1<<DT_RPATH))
821 p->rpath_orig = p->strings + dyn[DT_RPATH];
822 if (dyn[0]&(1<<DT_RUNPATH))
823 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
824 if (dyn[0]&(1<<DT_PLTGOT))
825 p->got = laddr(p, dyn[DT_PLTGOT]);
826 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
827 p->ghashtab = laddr(p, *dyn);
828 if (search_vec(p->dynv, dyn, DT_VERSYM))
829 p->versym = laddr(p, *dyn);
830 }
831
832 static size_t count_syms(struct dso *p)
833 {
834 if (p->hashtab) return p->hashtab[1];
835
836 size_t nsym, i;
837 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
838 uint32_t *hashval;
839 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
840 if (buckets[i] > nsym)
841 nsym = buckets[i];
842 }
843 if (nsym) {
844 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
845 do nsym++;
846 while (!(*hashval++ & 1));
847 }
848 return nsym;
849 }
850
851 static void *dl_mmap(size_t n)
852 {
853 void *p;
854 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
855 #ifdef SYS_mmap2
856 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
857 #else
858 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
859 #endif
860 return p == MAP_FAILED ? 0 : p;
861 }
862
863 static void makefuncdescs(struct dso *p)
864 {
865 static int self_done;
866 size_t nsym = count_syms(p);
867 size_t i, size = nsym * sizeof(*p->funcdescs);
868
869 if (!self_done) {
870 p->funcdescs = dl_mmap(size);
871 self_done = 1;
872 } else {
873 p->funcdescs = malloc(size);
874 }
875 if (!p->funcdescs) {
876 if (!runtime) a_crash();
877 error("Error allocating function descriptors for %s", p->name);
878 longjmp(*rtld_fail, 1);
879 }
880 for (i=0; i<nsym; i++) {
881 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
882 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
883 p->funcdescs[i].got = p->got;
884 } else {
885 p->funcdescs[i].addr = 0;
886 p->funcdescs[i].got = 0;
887 }
888 }
889 }
890
891 static struct dso *load_library(const char *name, struct dso *needed_by)
892 {
893 char buf[2*NAME_MAX+2];
894 const char *pathname;
895 unsigned char *map;
896 struct dso *p, temp_dso = {0};
897 int fd;
898 struct stat st;
899 size_t alloc_size;
900 int n_th = 0;
901 int is_self = 0;
902
903 if (!*name) {
904 errno = EINVAL;
905 return 0;
906 }
907
908 /* Catch and block attempts to reload the implementation itself */
909 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
910 static const char *rp, reserved[] =
911 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
912 char *z = strchr(name, '.');
913 if (z) {
914 size_t l = z-name;
915 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
916 if (*rp) {
917 if (ldd_mode) {
918 /* Track which names have been resolved
919 * and only report each one once. */
920 static unsigned reported;
921 unsigned mask = 1U<<(rp-reserved);
922 if (!(reported & mask)) {
923 reported |= mask;
924 dprintf(1, "\t%s => %s (%p)\n",
925 name, ldso.name,
926 ldso.base);
927 }
928 }
929 is_self = 1;
930 }
931 }
932 }
933 if (!strcmp(name, ldso.name)) is_self = 1;
934 if (is_self) {
935 if (!ldso.prev) {
936 tail->next = &ldso;
937 ldso.prev = tail;
938 tail = ldso.next ? ldso.next : &ldso;
939 }
940 return &ldso;
941 }
942 if (strchr(name, '/')) {
943 pathname = name;
944 fd = open(name, O_RDONLY|O_CLOEXEC);
945 } else {
946 /* Search for the name to see if it's already loaded */
947 for (p=head->next; p; p=p->next) {
948 if (p->shortname && !strcmp(p->shortname, name)) {
949 p->refcnt++;
950 return p;
951 }
952 }
953 if (strlen(name) > NAME_MAX) return 0;
954 fd = -1;
955 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
956 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
957 if (fixup_rpath(p, buf, sizeof buf) < 0)
958 fd = -2; /* Inhibit further search. */
959 if (p->rpath)
960 fd = path_open(name, p->rpath, buf, sizeof buf);
961 }
962 if (fd == -1) {
963 if (!sys_path) {
964 char *prefix = 0;
965 size_t prefix_len;
966 if (ldso.name[0]=='/') {
967 char *s, *t, *z;
968 for (s=t=z=ldso.name; *s; s++)
969 if (*s=='/') z=t, t=s;
970 prefix_len = z-ldso.name;
971 if (prefix_len < PATH_MAX)
972 prefix = ldso.name;
973 }
974 if (!prefix) {
975 prefix = "";
976 prefix_len = 0;
977 }
978 char etc_ldso_path[prefix_len + 1
979 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
980 snprintf(etc_ldso_path, sizeof etc_ldso_path,
981 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
982 (int)prefix_len, prefix);
983 FILE *f = fopen(etc_ldso_path, "rbe");
984 if (f) {
985 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
986 free(sys_path);
987 sys_path = "";
988 }
989 fclose(f);
990 } else if (errno != ENOENT) {
991 sys_path = "";
992 }
993 }
994 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
995 fd = path_open(name, sys_path, buf, sizeof buf);
996 }
997 pathname = buf;
998 }
999 if (fd < 0) return 0;
1000 if (fstat(fd, &st) < 0) {
1001 close(fd);
1002 return 0;
1003 }
1004 for (p=head->next; p; p=p->next) {
1005 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1006 /* If this library was previously loaded with a
1007 * pathname but a search found the same inode,
1008 * setup its shortname so it can be found by name. */
1009 if (!p->shortname && pathname != name)
1010 p->shortname = strrchr(p->name, '/')+1;
1011 close(fd);
1012 p->refcnt++;
1013 return p;
1014 }
1015 }
1016 map = noload ? 0 : map_library(fd, &temp_dso);
1017 close(fd);
1018 if (!map) return 0;
1019
1020 /* Allocate storage for the new DSO. When there is TLS, this
1021 * storage must include a reservation for all pre-existing
1022 * threads to obtain copies of both the new TLS, and an
1023 * extended DTV capable of storing an additional slot for
1024 * the newly-loaded DSO. */
1025 alloc_size = sizeof *p + strlen(pathname) + 1;
1026 if (runtime && temp_dso.tls.image) {
1027 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1028 + sizeof(void *) * (tls_cnt+3);
1029 n_th = libc.threads_minus_1 + 1;
1030 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1031 else alloc_size += n_th * per_th;
1032 }
1033 p = calloc(1, alloc_size);
1034 if (!p) {
1035 unmap_library(&temp_dso);
1036 return 0;
1037 }
1038 memcpy(p, &temp_dso, sizeof temp_dso);
1039 decode_dyn(p);
1040 p->dev = st.st_dev;
1041 p->ino = st.st_ino;
1042 p->refcnt = 1;
1043 p->needed_by = needed_by;
1044 p->name = p->buf;
1045 strcpy(p->name, pathname);
1046 /* Add a shortname only if name arg was not an explicit pathname. */
1047 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1048 if (p->tls.image) {
1049 p->tls_id = ++tls_cnt;
1050 tls_align = MAXP2(tls_align, p->tls.align);
1051 #ifdef TLS_ABOVE_TP
1052 p->tls.offset = tls_offset + ( (tls_align-1) &
1053 -(tls_offset + (uintptr_t)p->tls.image) );
1054 tls_offset += p->tls.size;
1055 #else
1056 tls_offset += p->tls.size + p->tls.align - 1;
1057 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1058 & (p->tls.align-1);
1059 p->tls.offset = tls_offset;
1060 #endif
1061 p->new_dtv = (void *)(-sizeof(size_t) &
1062 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1063 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1064 if (tls_tail) tls_tail->next = &p->tls;
1065 else libc.tls_head = &p->tls;
1066 tls_tail = &p->tls;
1067 }
1068
1069 tail->next = p;
1070 p->prev = tail;
1071 tail = p;
1072
1073 if (DL_FDPIC) makefuncdescs(p);
1074
1075 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1076
1077 return p;
1078 }
1079
1080 static void load_deps(struct dso *p)
1081 {
1082 size_t i, ndeps=0;
1083 struct dso ***deps = &p->deps, **tmp, *dep;
1084 for (; p; p=p->next) {
1085 for (i=0; p->dynv[i]; i+=2) {
1086 if (p->dynv[i] != DT_NEEDED) continue;
1087 dep = load_library(p->strings + p->dynv[i+1], p);
1088 if (!dep) {
1089 error("Error loading shared library %s: %m (needed by %s)",
1090 p->strings + p->dynv[i+1], p->name);
1091 if (runtime) longjmp(*rtld_fail, 1);
1092 continue;
1093 }
1094 if (runtime) {
1095 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1096 if (!tmp) longjmp(*rtld_fail, 1);
1097 tmp[ndeps++] = dep;
1098 tmp[ndeps] = 0;
1099 *deps = tmp;
1100 }
1101 }
1102 }
1103 }
1104
1105 static void load_preload(char *s)
1106 {
1107 int tmp;
1108 char *z;
1109 for (z=s; *z; s=z) {
1110 for ( ; *s && (isspace(*s) || *s==':'); s++);
1111 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1112 tmp = *z;
1113 *z = 0;
1114 load_library(s, 0);
1115 *z = tmp;
1116 }
1117 }
1118
1119 static void make_global(struct dso *p)
1120 {
1121 for (; p; p=p->next) p->global = 1;
1122 }
1123
1124 static void do_mips_relocs(struct dso *p, size_t *got)
1125 {
1126 size_t i, j, rel[2];
1127 unsigned char *base = p->base;
1128 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1129 if (p==&ldso) {
1130 got += i;
1131 } else {
1132 while (i--) *got++ += (size_t)base;
1133 }
1134 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1135 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1136 Sym *sym = p->syms + j;
1137 rel[0] = (unsigned char *)got - base;
1138 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1139 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
1140 do_relocs(p, rel, sizeof rel, 2);
1141 }
1142 }
1143
1144 static void reloc_all(struct dso *p)
1145 {
1146 size_t dyn[DYN_CNT];
1147 for (; p; p=p->next) {
1148 if (p->relocated) continue;
1149 decode_vec(p->dynv, dyn, DYN_CNT);
1150 if (NEED_MIPS_GOT_RELOCS)
1151 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1152 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1153 2+(dyn[DT_PLTREL]==DT_RELA));
1154 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1155 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1156
1157 if (head != &ldso && p->relro_start != p->relro_end &&
1158 mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1159 && errno != ENOSYS) {
1160 error("Error relocating %s: RELRO protection failed: %m",
1161 p->name);
1162 if (runtime) longjmp(*rtld_fail, 1);
1163 }
1164
1165 p->relocated = 1;
1166 }
1167 }
1168
1169 static void kernel_mapped_dso(struct dso *p)
1170 {
1171 size_t min_addr = -1, max_addr = 0, cnt;
1172 Phdr *ph = p->phdr;
1173 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1174 if (ph->p_type == PT_DYNAMIC) {
1175 p->dynv = laddr(p, ph->p_vaddr);
1176 } else if (ph->p_type == PT_GNU_RELRO) {
1177 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1178 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1179 }
1180 if (ph->p_type != PT_LOAD) continue;
1181 if (ph->p_vaddr < min_addr)
1182 min_addr = ph->p_vaddr;
1183 if (ph->p_vaddr+ph->p_memsz > max_addr)
1184 max_addr = ph->p_vaddr+ph->p_memsz;
1185 }
1186 min_addr &= -PAGE_SIZE;
1187 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1188 p->map = p->base + min_addr;
1189 p->map_len = max_addr - min_addr;
1190 p->kernel_mapped = 1;
1191 }
1192
1193 void __libc_exit_fini()
1194 {
1195 struct dso *p;
1196 size_t dyn[DYN_CNT];
1197 for (p=fini_head; p; p=p->fini_next) {
1198 if (!p->constructed) continue;
1199 decode_vec(p->dynv, dyn, DYN_CNT);
1200 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1201 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1202 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1203 while (n--) ((void (*)(void))*--fn)();
1204 }
1205 #ifndef NO_LEGACY_INITFINI
1206 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1207 fpaddr(p, dyn[DT_FINI])();
1208 #endif
1209 }
1210 }
1211
1212 static void do_init_fini(struct dso *p)
1213 {
1214 size_t dyn[DYN_CNT];
1215 int need_locking = libc.threads_minus_1;
1216 /* Allow recursive calls that arise when a library calls
1217 * dlopen from one of its constructors, but block any
1218 * other threads until all ctors have finished. */
1219 if (need_locking) pthread_mutex_lock(&init_fini_lock);
1220 for (; p; p=p->prev) {
1221 if (p->constructed) continue;
1222 p->constructed = 1;
1223 decode_vec(p->dynv, dyn, DYN_CNT);
1224 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1225 p->fini_next = fini_head;
1226 fini_head = p;
1227 }
1228 #ifndef NO_LEGACY_INITFINI
1229 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1230 fpaddr(p, dyn[DT_INIT])();
1231 #endif
1232 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1233 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1234 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1235 while (n--) ((void (*)(void))*fn++)();
1236 }
1237 if (!need_locking && libc.threads_minus_1) {
1238 need_locking = 1;
1239 pthread_mutex_lock(&init_fini_lock);
1240 }
1241 }
1242 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1243 }
1244
1245 void __libc_start_init(void)
1246 {
1247 do_init_fini(tail);
1248 }
1249
1250 static void dl_debug_state(void)
1251 {
1252 }
1253
1254 weak_alias(dl_debug_state, _dl_debug_state);
1255
1256 void __init_tls(size_t *auxv)
1257 {
1258 }
1259
1260 __attribute__((__visibility__("hidden")))
1261 void *__tls_get_new(size_t *v)
1262 {
1263 pthread_t self = __pthread_self();
1264
1265 /* Block signals to make accessing new TLS async-signal-safe */
1266 sigset_t set;
1267 __block_all_sigs(&set);
1268 if (v[0]<=(size_t)self->dtv[0]) {
1269 __restore_sigs(&set);
1270 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1271 }
1272
1273 /* This is safe without any locks held because, if the caller
1274 * is able to request the Nth entry of the DTV, the DSO list
1275 * must be valid at least that far out and it was synchronized
1276 * at program startup or by an already-completed call to dlopen. */
1277 struct dso *p;
1278 for (p=head; p->tls_id != v[0]; p=p->next);
1279
1280 /* Get new DTV space from new DSO if needed */
1281 if (v[0] > (size_t)self->dtv[0]) {
1282 void **newdtv = p->new_dtv +
1283 (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1284 memcpy(newdtv, self->dtv,
1285 ((size_t)self->dtv[0]+1) * sizeof(void *));
1286 newdtv[0] = (void *)v[0];
1287 self->dtv = self->dtv_copy = newdtv;
1288 }
1289
1290 /* Get new TLS memory from all new DSOs up to the requested one */
1291 unsigned char *mem;
1292 for (p=head; ; p=p->next) {
1293 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1294 mem = p->new_tls + (p->tls.size + p->tls.align)
1295 * a_fetch_add(&p->new_tls_idx,1);
1296 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1297 & (p->tls.align-1);
1298 self->dtv[p->tls_id] = mem;
1299 memcpy(mem, p->tls.image, p->tls.len);
1300 if (p->tls_id == v[0]) break;
1301 }
1302 __restore_sigs(&set);
1303 return mem + v[1] + DTP_OFFSET;
1304 }
1305
1306 static void update_tls_size()
1307 {
1308 libc.tls_cnt = tls_cnt;
1309 libc.tls_align = tls_align;
1310 libc.tls_size = ALIGN(
1311 (1+tls_cnt) * sizeof(void *) +
1312 tls_offset +
1313 sizeof(struct pthread) +
1314 tls_align * 2,
1315 tls_align);
1316 }
1317
1318 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1319 * following stage 2 and stage 3 functions via primitive symbolic lookup
1320 * since it does not have access to their addresses to begin with. */
1321
1322 /* Stage 2 of the dynamic linker is called after relative relocations
1323 * have been processed. It can make function calls to static functions
1324 * and access string literals and static data, but cannot use extern
1325 * symbols. Its job is to perform symbolic relocations on the dynamic
1326 * linker itself, but some of the relocations performed may need to be
1327 * replaced later due to copy relocations in the main program. */
1328
1329 __attribute__((__visibility__("hidden")))
1330 void __dls2(unsigned char *base, size_t *sp)
1331 {
1332 if (DL_FDPIC) {
1333 void *p1 = (void *)sp[-2];
1334 void *p2 = (void *)sp[-1];
1335 if (!p1) {
1336 size_t *auxv, aux[AUX_CNT];
1337 for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1338 decode_vec(auxv, aux, AUX_CNT);
1339 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1340 else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1341 }
1342 app_loadmap = p2 ? p1 : 0;
1343 ldso.loadmap = p2 ? p2 : p1;
1344 ldso.base = laddr(&ldso, 0);
1345 } else {
1346 ldso.base = base;
1347 }
1348 Ehdr *ehdr = (void *)ldso.base;
1349 ldso.name = ldso.shortname = "libc.so";
1350 ldso.global = 1;
1351 ldso.phnum = ehdr->e_phnum;
1352 ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1353 ldso.phentsize = ehdr->e_phentsize;
1354 kernel_mapped_dso(&ldso);
1355 decode_dyn(&ldso);
1356
1357 if (DL_FDPIC) makefuncdescs(&ldso);
1358
1359 /* Prepare storage for to save clobbered REL addends so they
1360 * can be reused in stage 3. There should be very few. If
1361 * something goes wrong and there are a huge number, abort
1362 * instead of risking stack overflow. */
1363 size_t dyn[DYN_CNT];
1364 decode_vec(ldso.dynv, dyn, DYN_CNT);
1365 size_t *rel = laddr(&ldso, dyn[DT_REL]);
1366 size_t rel_size = dyn[DT_RELSZ];
1367 size_t symbolic_rel_cnt = 0;
1368 apply_addends_to = rel;
1369 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1370 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1371 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1372 size_t addends[symbolic_rel_cnt+1];
1373 saved_addends = addends;
1374
1375 head = &ldso;
1376 reloc_all(&ldso);
1377
1378 ldso.relocated = 0;
1379
1380 /* Call dynamic linker stage-3, __dls3, looking it up
1381 * symbolically as a barrier against moving the address
1382 * load across the above relocation processing. */
1383 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1384 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1385 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1386 }
1387
1388 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1389 * fully functional. Its job is to load (if not already loaded) and
1390 * process dependencies and relocations for the main application and
1391 * transfer control to its entry point. */
1392
1393 _Noreturn void __dls3(size_t *sp)
1394 {
1395 static struct dso app, vdso;
1396 size_t aux[AUX_CNT], *auxv;
1397 size_t i;
1398 char *env_preload=0;
1399 size_t vdso_base;
1400 int argc = *sp;
1401 char **argv = (void *)(sp+1);
1402 char **argv_orig = argv;
1403 char **envp = argv+argc+1;
1404
1405 /* Find aux vector just past environ[] and use it to initialize
1406 * global data that may be needed before we can make syscalls. */
1407 __environ = envp;
1408 for (i=argc+1; argv[i]; i++);
1409 libc.auxv = auxv = (void *)(argv+i+1);
1410 decode_vec(auxv, aux, AUX_CNT);
1411 __hwcap = aux[AT_HWCAP];
1412 libc.page_size = aux[AT_PAGESZ];
1413 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1414 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1415
1416 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1417 * use during dynamic linking. If possible it will also serve as the
1418 * thread pointer at runtime. */
1419 libc.tls_size = sizeof builtin_tls;
1420 libc.tls_align = tls_align;
1421 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1422 a_crash();
1423 }
1424
1425 /* Only trust user/env if kernel says we're not suid/sgid */
1426 if (!libc.secure) {
1427 env_path = getenv("LD_LIBRARY_PATH");
1428 env_preload = getenv("LD_PRELOAD");
1429 }
1430
1431 /* If the main program was already loaded by the kernel,
1432 * AT_PHDR will point to some location other than the dynamic
1433 * linker's program headers. */
1434 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1435 size_t interp_off = 0;
1436 size_t tls_image = 0;
1437 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1438 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1439 app.phnum = aux[AT_PHNUM];
1440 app.phentsize = aux[AT_PHENT];
1441 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1442 if (phdr->p_type == PT_PHDR)
1443 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1444 else if (phdr->p_type == PT_INTERP)
1445 interp_off = (size_t)phdr->p_vaddr;
1446 else if (phdr->p_type == PT_TLS) {
1447 tls_image = phdr->p_vaddr;
1448 app.tls.len = phdr->p_filesz;
1449 app.tls.size = phdr->p_memsz;
1450 app.tls.align = phdr->p_align;
1451 }
1452 }
1453 if (DL_FDPIC) app.loadmap = app_loadmap;
1454 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1455 if (interp_off) ldso.name = laddr(&app, interp_off);
1456 if ((aux[0] & (1UL<<AT_EXECFN))
1457 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1458 app.name = (char *)aux[AT_EXECFN];
1459 else
1460 app.name = argv[0];
1461 kernel_mapped_dso(&app);
1462 } else {
1463 int fd;
1464 char *ldname = argv[0];
1465 size_t l = strlen(ldname);
1466 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1467 argv++;
1468 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1469 char *opt = argv[0]+2;
1470 *argv++ = (void *)-1;
1471 if (!*opt) {
1472 break;
1473 } else if (!memcmp(opt, "list", 5)) {
1474 ldd_mode = 1;
1475 } else if (!memcmp(opt, "library-path", 12)) {
1476 if (opt[12]=='=') env_path = opt+13;
1477 else if (opt[12]) *argv = 0;
1478 else if (*argv) env_path = *argv++;
1479 } else if (!memcmp(opt, "preload", 7)) {
1480 if (opt[7]=='=') env_preload = opt+8;
1481 else if (opt[7]) *argv = 0;
1482 else if (*argv) env_preload = *argv++;
1483 } else {
1484 argv[0] = 0;
1485 }
1486 }
1487 argv[-1] = (void *)(argc - (argv-argv_orig));
1488 if (!argv[0]) {
1489 dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1490 "Version %s\n"
1491 "Dynamic Program Loader\n"
1492 "Usage: %s [options] [--] pathname%s\n",
1493 __libc_get_version(), ldname,
1494 ldd_mode ? "" : " [args]");
1495 _exit(1);
1496 }
1497 fd = open(argv[0], O_RDONLY);
1498 if (fd < 0) {
1499 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1500 _exit(1);
1501 }
1502 runtime = 1;
1503 Ehdr *ehdr = (void *)map_library(fd, &app);
1504 if (!ehdr) {
1505 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1506 _exit(1);
1507 }
1508 runtime = 0;
1509 close(fd);
1510 ldso.name = ldname;
1511 app.name = argv[0];
1512 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1513 /* Find the name that would have been used for the dynamic
1514 * linker had ldd not taken its place. */
1515 if (ldd_mode) {
1516 for (i=0; i<app.phnum; i++) {
1517 if (app.phdr[i].p_type == PT_INTERP)
1518 ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1519 }
1520 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1521 }
1522 }
1523 if (app.tls.size) {
1524 libc.tls_head = &app.tls;
1525 app.tls_id = tls_cnt = 1;
1526 #ifdef TLS_ABOVE_TP
1527 app.tls.offset = 0;
1528 tls_offset = app.tls.size
1529 + ( -((uintptr_t)app.tls.image + app.tls.size)
1530 & (app.tls.align-1) );
1531 #else
1532 tls_offset = app.tls.offset = app.tls.size
1533 + ( -((uintptr_t)app.tls.image + app.tls.size)
1534 & (app.tls.align-1) );
1535 #endif
1536 tls_align = MAXP2(tls_align, app.tls.align);
1537 }
1538 app.global = 1;
1539 decode_dyn(&app);
1540 if (DL_FDPIC) {
1541 makefuncdescs(&app);
1542 if (!app.loadmap) {
1543 app.loadmap = (void *)&app_dummy_loadmap;
1544 app.loadmap->nsegs = 1;
1545 app.loadmap->segs[0].addr = (size_t)app.map;
1546 app.loadmap->segs[0].p_vaddr = (size_t)app.map
1547 - (size_t)app.base;
1548 app.loadmap->segs[0].p_memsz = app.map_len;
1549 }
1550 argv[-3] = (void *)app.loadmap;
1551 }
1552
1553 /* Attach to vdso, if provided by the kernel */
1554 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1555 Ehdr *ehdr = (void *)vdso_base;
1556 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1557 vdso.phnum = ehdr->e_phnum;
1558 vdso.phentsize = ehdr->e_phentsize;
1559 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1560 if (phdr->p_type == PT_DYNAMIC)
1561 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1562 if (phdr->p_type == PT_LOAD)
1563 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1564 }
1565 vdso.name = "";
1566 vdso.shortname = "linux-gate.so.1";
1567 vdso.global = 1;
1568 vdso.relocated = 1;
1569 decode_dyn(&vdso);
1570 vdso.prev = &ldso;
1571 ldso.next = &vdso;
1572 }
1573
1574 /* Initial dso chain consists only of the app. */
1575 head = tail = &app;
1576
1577 /* Donate unused parts of app and library mapping to malloc */
1578 reclaim_gaps(&app);
1579 reclaim_gaps(&ldso);
1580
1581 /* Load preload/needed libraries, add their symbols to the global
1582 * namespace, and perform all remaining relocations. */
1583 if (env_preload) load_preload(env_preload);
1584 load_deps(&app);
1585 make_global(&app);
1586
1587 #ifndef DYNAMIC_IS_RO
1588 for (i=0; app.dynv[i]; i+=2)
1589 if (app.dynv[i]==DT_DEBUG)
1590 app.dynv[i+1] = (size_t)&debug;
1591 #endif
1592
1593 /* The main program must be relocated LAST since it may contin
1594 * copy relocations which depend on libraries' relocations. */
1595 reloc_all(app.next);
1596 reloc_all(&app);
1597
1598 update_tls_size();
1599 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1600 void *initial_tls = calloc(libc.tls_size, 1);
1601 if (!initial_tls) {
1602 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1603 argv[0], libc.tls_size);
1604 _exit(127);
1605 }
1606 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1607 a_crash();
1608 }
1609 } else {
1610 size_t tmp_tls_size = libc.tls_size;
1611 pthread_t self = __pthread_self();
1612 /* Temporarily set the tls size to the full size of
1613 * builtin_tls so that __copy_tls will use the same layout
1614 * as it did for before. Then check, just to be safe. */
1615 libc.tls_size = sizeof builtin_tls;
1616 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1617 libc.tls_size = tmp_tls_size;
1618 }
1619 static_tls_cnt = tls_cnt;
1620
1621 if (ldso_fail) _exit(127);
1622 if (ldd_mode) _exit(0);
1623
1624 /* Switch to runtime mode: any further failures in the dynamic
1625 * linker are a reportable failure rather than a fatal startup
1626 * error. */
1627 runtime = 1;
1628
1629 debug.ver = 1;
1630 debug.bp = dl_debug_state;
1631 debug.head = head;
1632 debug.base = ldso.base;
1633 debug.state = 0;
1634 _dl_debug_state();
1635
1636 errno = 0;
1637
1638 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1639 for(;;);
1640 }
1641
1642 void *dlopen(const char *file, int mode)
1643 {
1644 struct dso *volatile p, *orig_tail, *next;
1645 struct tls_module *orig_tls_tail;
1646 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1647 size_t i;
1648 int cs;
1649 jmp_buf jb;
1650
1651 if (!file) return head;
1652
1653 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1654 pthread_rwlock_wrlock(&lock);
1655 __inhibit_ptc();
1656
1657 p = 0;
1658 orig_tls_tail = tls_tail;
1659 orig_tls_cnt = tls_cnt;
1660 orig_tls_offset = tls_offset;
1661 orig_tls_align = tls_align;
1662 orig_tail = tail;
1663 noload = mode & RTLD_NOLOAD;
1664
1665 rtld_fail = &jb;
1666 if (setjmp(*rtld_fail)) {
1667 /* Clean up anything new that was (partially) loaded */
1668 if (p && p->deps) for (i=0; p->deps[i]; i++)
1669 if (p->deps[i]->global < 0)
1670 p->deps[i]->global = 0;
1671 for (p=orig_tail->next; p; p=next) {
1672 next = p->next;
1673 while (p->td_index) {
1674 void *tmp = p->td_index->next;
1675 free(p->td_index);
1676 p->td_index = tmp;
1677 }
1678 free(p->funcdescs);
1679 if (p->rpath != p->rpath_orig)
1680 free(p->rpath);
1681 free(p->deps);
1682 unmap_library(p);
1683 free(p);
1684 }
1685 if (!orig_tls_tail) libc.tls_head = 0;
1686 tls_tail = orig_tls_tail;
1687 tls_cnt = orig_tls_cnt;
1688 tls_offset = orig_tls_offset;
1689 tls_align = orig_tls_align;
1690 tail = orig_tail;
1691 tail->next = 0;
1692 p = 0;
1693 goto end;
1694 } else p = load_library(file, head);
1695
1696 if (!p) {
1697 error(noload ?
1698 "Library %s is not already loaded" :
1699 "Error loading shared library %s: %m",
1700 file);
1701 goto end;
1702 }
1703
1704 /* First load handling */
1705 if (!p->deps) {
1706 load_deps(p);
1707 if (p->deps) for (i=0; p->deps[i]; i++)
1708 if (!p->deps[i]->global)
1709 p->deps[i]->global = -1;
1710 if (!p->global) p->global = -1;
1711 reloc_all(p);
1712 if (p->deps) for (i=0; p->deps[i]; i++)
1713 if (p->deps[i]->global < 0)
1714 p->deps[i]->global = 0;
1715 if (p->global < 0) p->global = 0;
1716 }
1717
1718 if (mode & RTLD_GLOBAL) {
1719 if (p->deps) for (i=0; p->deps[i]; i++)
1720 p->deps[i]->global = 1;
1721 p->global = 1;
1722 }
1723
1724 update_tls_size();
1725 _dl_debug_state();
1726 orig_tail = tail;
1727 end:
1728 __release_ptc();
1729 if (p) gencnt++;
1730 pthread_rwlock_unlock(&lock);
1731 if (p) do_init_fini(orig_tail);
1732 pthread_setcancelstate(cs, 0);
1733 return p;
1734 }
1735
1736 __attribute__((__visibility__("hidden")))
1737 int __dl_invalid_handle(void *h)
1738 {
1739 struct dso *p;
1740 for (p=head; p; p=p->next) if (h==p) return 0;
1741 error("Invalid library handle %p", (void *)h);
1742 return 1;
1743 }
1744
1745 static void *addr2dso(size_t a)
1746 {
1747 struct dso *p;
1748 size_t i;
1749 if (DL_FDPIC) for (p=head; p; p=p->next) {
1750 i = count_syms(p);
1751 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1752 return p;
1753 }
1754 for (p=head; p; p=p->next) {
1755 if (DL_FDPIC && p->loadmap) {
1756 for (i=0; i<p->loadmap->nsegs; i++) {
1757 if (a-p->loadmap->segs[i].p_vaddr
1758 < p->loadmap->segs[i].p_memsz)
1759 return p;
1760 }
1761 } else {
1762 if (a-(size_t)p->map < p->map_len)
1763 return p;
1764 }
1765 }
1766 return 0;
1767 }
1768
1769 void *__tls_get_addr(size_t *);
1770
1771 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1772 {
1773 size_t i;
1774 uint32_t h = 0, gh = 0, *ght;
1775 Sym *sym;
1776 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1777 if (p == RTLD_DEFAULT) {
1778 p = head;
1779 } else if (p == RTLD_NEXT) {
1780 p = addr2dso((size_t)ra);
1781 if (!p) p=head;
1782 p = p->next;
1783 }
1784 struct symdef def = find_sym(p, s, 0);
1785 if (!def.sym) goto failed;
1786 if ((def.sym->st_info&0xf) == STT_TLS)
1787 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1788 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1789 return def.dso->funcdescs + (def.sym - def.dso->syms);
1790 return laddr(def.dso, def.sym->st_value);
1791 }
1792 if (__dl_invalid_handle(p))
1793 return 0;
1794 if ((ght = p->ghashtab)) {
1795 gh = gnu_hash(s);
1796 sym = gnu_lookup(gh, ght, p, s);
1797 } else {
1798 h = sysv_hash(s);
1799 sym = sysv_lookup(s, h, p);
1800 }
1801 if (sym && (sym->st_info&0xf) == STT_TLS)
1802 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1803 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1804 return p->funcdescs + (sym - p->syms);
1805 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1806 return laddr(p, sym->st_value);
1807 if (p->deps) for (i=0; p->deps[i]; i++) {
1808 if ((ght = p->deps[i]->ghashtab)) {
1809 if (!gh) gh = gnu_hash(s);
1810 sym = gnu_lookup(gh, ght, p->deps[i], s);
1811 } else {
1812 if (!h) h = sysv_hash(s);
1813 sym = sysv_lookup(s, h, p->deps[i]);
1814 }
1815 if (sym && (sym->st_info&0xf) == STT_TLS)
1816 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1817 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1818 return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1819 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1820 return laddr(p->deps[i], sym->st_value);
1821 }
1822 failed:
1823 error("Symbol not found: %s", s);
1824 return 0;
1825 }
1826
1827 int dladdr(const void *addr, Dl_info *info)
1828 {
1829 struct dso *p;
1830 Sym *sym, *bestsym;
1831 uint32_t nsym;
1832 char *strings;
1833 void *best = 0;
1834
1835 pthread_rwlock_rdlock(&lock);
1836 p = addr2dso((size_t)addr);
1837 pthread_rwlock_unlock(&lock);
1838
1839 if (!p) return 0;
1840
1841 sym = p->syms;
1842 strings = p->strings;
1843 nsym = count_syms(p);
1844
1845 if (DL_FDPIC) {
1846 size_t idx = ((size_t)addr-(size_t)p->funcdescs)
1847 / sizeof(*p->funcdescs);
1848 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1849 best = p->funcdescs + idx;
1850 bestsym = sym + idx;
1851 }
1852 }
1853
1854 if (!best) for (; nsym; nsym--, sym++) {
1855 if (sym->st_value
1856 && (1<<(sym->st_info&0xf) & OK_TYPES)
1857 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1858 void *symaddr = laddr(p, sym->st_value);
1859 if (symaddr > addr || symaddr < best)
1860 continue;
1861 best = symaddr;
1862 bestsym = sym;
1863 if (addr == symaddr)
1864 break;
1865 }
1866 }
1867
1868 if (!best) return 0;
1869
1870 if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
1871 best = p->funcdescs + (bestsym - p->syms);
1872
1873 info->dli_fname = p->name;
1874 info->dli_fbase = p->base;
1875 info->dli_sname = strings + bestsym->st_name;
1876 info->dli_saddr = best;
1877
1878 return 1;
1879 }
1880
1881 __attribute__((__visibility__("hidden")))
1882 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1883 {
1884 void *res;
1885 pthread_rwlock_rdlock(&lock);
1886 res = do_dlsym(p, s, ra);
1887 pthread_rwlock_unlock(&lock);
1888 return res;
1889 }
1890
1891 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1892 {
1893 struct dso *current;
1894 struct dl_phdr_info info;
1895 int ret = 0;
1896 for(current = head; current;) {
1897 info.dlpi_addr = (uintptr_t)current->base;
1898 info.dlpi_name = current->name;
1899 info.dlpi_phdr = current->phdr;
1900 info.dlpi_phnum = current->phnum;
1901 info.dlpi_adds = gencnt;
1902 info.dlpi_subs = 0;
1903 info.dlpi_tls_modid = current->tls_id;
1904 info.dlpi_tls_data = current->tls.image;
1905
1906 ret = (callback)(&info, sizeof (info), data);
1907
1908 if (ret != 0) break;
1909
1910 pthread_rwlock_rdlock(&lock);
1911 current = current->next;
1912 pthread_rwlock_unlock(&lock);
1913 }
1914 return ret;
1915 }
1916 #else
1917 void *dlopen(const char *file, int mode)
1918 {
1919 error("Dynamic loading not supported");
1920 return 0;
1921 }
1922 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1923 {
1924 error("Symbol not found: %s", s);
1925 return 0;
1926 }
1927 #endif
1928
1929 __attribute__((__visibility__("hidden")))
1930 int __dl_invalid_handle(void *);
1931
1932 int __dlinfo(void *dso, int req, void *res)
1933 {
1934 if (__dl_invalid_handle(dso)) return -1;
1935 if (req != RTLD_DI_LINKMAP) {
1936 error("Unsupported request %d", req);
1937 return -1;
1938 }
1939 *(struct link_map **)res = dso;
1940 return 0;
1941 }
1942
1943 int dlclose(void *p)
1944 {
1945 return __dl_invalid_handle(p);
1946 }
1947
1948 __attribute__((__visibility__("hidden")))
1949 void __dl_vseterr(const char *, va_list);
1950
1951 static void error(const char *fmt, ...)
1952 {
1953 va_list ap;
1954 va_start(ap, fmt);
1955 #ifdef SHARED
1956 if (!runtime) {
1957 vdprintf(2, fmt, ap);
1958 dprintf(2, "\n");
1959 ldso_fail = 1;
1960 va_end(ap);
1961 return;
1962 }
1963 #endif
1964 __dl_vseterr(fmt, ap);
1965 va_end(ap);
1966 }
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