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fix use of uninitialized pointer in gettext core
[musl.git] / ldso / dynlink.c
bloba03f75e3589cc18d366f7f634b868a4ae790dcbe
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 #define MAXP2(a,b) (-(-(a)&-(b)))
27 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
28
29 struct debug {
30 int ver;
31 void *head;
32 void (*bp)(void);
33 int state;
34 void *base;
35 };
36
37 struct td_index {
38 size_t args[2];
39 struct td_index *next;
40 };
41
42 struct dso {
43 #if DL_FDPIC
44 struct fdpic_loadmap *loadmap;
45 #else
46 unsigned char *base;
47 #endif
48 char *name;
49 size_t *dynv;
50 struct dso *next, *prev;
51
52 Phdr *phdr;
53 int phnum;
54 size_t phentsize;
55 int refcnt;
56 Sym *syms;
57 Elf_Symndx *hashtab;
58 uint32_t *ghashtab;
59 int16_t *versym;
60 char *strings;
61 unsigned char *map;
62 size_t map_len;
63 dev_t dev;
64 ino_t ino;
65 signed char global;
66 char relocated;
67 char constructed;
68 char kernel_mapped;
69 struct dso **deps, *needed_by;
70 char *rpath_orig, *rpath;
71 struct tls_module tls;
72 size_t tls_id;
73 size_t relro_start, relro_end;
74 void **new_dtv;
75 unsigned char *new_tls;
76 volatile int new_dtv_idx, new_tls_idx;
77 struct td_index *td_index;
78 struct dso *fini_next;
79 char *shortname;
80 #if DL_FDPIC
81 unsigned char *base;
82 #else
83 struct fdpic_loadmap *loadmap;
84 #endif
85 struct funcdesc {
86 void *addr;
87 size_t *got;
88 } *funcdescs;
89 size_t *got;
90 char buf[];
91 };
92
93 struct symdef {
94 Sym *sym;
95 struct dso *dso;
96 };
97
98 int __init_tp(void *);
99 void __init_libc(char **, char *);
100 void *__copy_tls(unsigned char *);
101
102 __attribute__((__visibility__("hidden")))
103 const char *__libc_get_version(void);
104
105 static struct builtin_tls {
106 char c;
107 struct pthread pt;
108 void *space[16];
109 } builtin_tls[1];
110 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
111
112 #define ADDEND_LIMIT 4096
113 static size_t *saved_addends, *apply_addends_to;
114
115 static struct dso ldso;
116 static struct dso *head, *tail, *fini_head;
117 static char *env_path, *sys_path;
118 static unsigned long long gencnt;
119 static int runtime;
120 static int ldd_mode;
121 static int ldso_fail;
122 static int noload;
123 static jmp_buf *rtld_fail;
124 static pthread_rwlock_t lock;
125 static struct debug debug;
126 static struct tls_module *tls_tail;
127 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
128 static size_t static_tls_cnt;
129 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
130 static struct fdpic_loadmap *app_loadmap;
131 static struct fdpic_dummy_loadmap app_dummy_loadmap;
132
133 struct debug *_dl_debug_addr = &debug;
134
135 __attribute__((__visibility__("hidden")))
136 void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
137
138 __attribute__((__visibility__("hidden")))
139 extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
140
141 weak_alias(__init_array_start, __init_array_end);
142 weak_alias(__fini_array_start, __fini_array_end);
143
144 static int dl_strcmp(const char *l, const char *r)
145 {
146 for (; *l==*r && *l; l++, r++);
147 return *(unsigned char *)l - *(unsigned char *)r;
148 }
149 #define strcmp(l,r) dl_strcmp(l,r)
150
151 /* Compute load address for a virtual address in a given dso. */
152 #if DL_FDPIC
153 static void *laddr(const struct dso *p, size_t v)
154 {
155 size_t j=0;
156 if (!p->loadmap) return p->base + v;
157 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
158 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
159 }
160 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
161 laddr(p, v), (p)->got })
162 #else
163 #define laddr(p, v) (void *)((p)->base + (v))
164 #define fpaddr(p, v) ((void (*)())laddr(p, v))
165 #endif
166
167 static void decode_vec(size_t *v, size_t *a, size_t cnt)
168 {
169 size_t i;
170 for (i=0; i<cnt; i++) a[i] = 0;
171 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
172 a[0] |= 1UL<<v[0];
173 a[v[0]] = v[1];
174 }
175 }
176
177 static int search_vec(size_t *v, size_t *r, size_t key)
178 {
179 for (; v[0]!=key; v+=2)
180 if (!v[0]) return 0;
181 *r = v[1];
182 return 1;
183 }
184
185 static uint32_t sysv_hash(const char *s0)
186 {
187 const unsigned char *s = (void *)s0;
188 uint_fast32_t h = 0;
189 while (*s) {
190 h = 16*h + *s++;
191 h ^= h>>24 & 0xf0;
192 }
193 return h & 0xfffffff;
194 }
195
196 static uint32_t gnu_hash(const char *s0)
197 {
198 const unsigned char *s = (void *)s0;
199 uint_fast32_t h = 5381;
200 for (; *s; s++)
201 h += h*32 + *s;
202 return h;
203 }
204
205 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
206 {
207 size_t i;
208 Sym *syms = dso->syms;
209 Elf_Symndx *hashtab = dso->hashtab;
210 char *strings = dso->strings;
211 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
212 if ((!dso->versym || dso->versym[i] >= 0)
213 && (!strcmp(s, strings+syms[i].st_name)))
214 return syms+i;
215 }
216 return 0;
217 }
218
219 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
220 {
221 uint32_t nbuckets = hashtab[0];
222 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
223 uint32_t i = buckets[h1 % nbuckets];
224
225 if (!i) return 0;
226
227 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
228
229 for (h1 |= 1; ; i++) {
230 uint32_t h2 = *hashval++;
231 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
232 && !strcmp(s, dso->strings + dso->syms[i].st_name))
233 return dso->syms+i;
234 if (h2 & 1) break;
235 }
236
237 return 0;
238 }
239
240 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
241 {
242 const size_t *bloomwords = (const void *)(hashtab+4);
243 size_t f = bloomwords[fofs & (hashtab[2]-1)];
244 if (!(f & fmask)) return 0;
245
246 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
247 if (!(f & 1)) return 0;
248
249 return gnu_lookup(h1, hashtab, dso, s);
250 }
251
252 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
253 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
254
255 #ifndef ARCH_SYM_REJECT_UND
256 #define ARCH_SYM_REJECT_UND(s) 0
257 #endif
258
259 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
260 {
261 uint32_t h = 0, gh, gho, *ght;
262 size_t ghm = 0;
263 struct symdef def = {0};
264 for (; dso; dso=dso->next) {
265 Sym *sym;
266 if (!dso->global) continue;
267 if ((ght = dso->ghashtab)) {
268 if (!ghm) {
269 gh = gnu_hash(s);
270 int maskbits = 8 * sizeof ghm;
271 gho = gh / maskbits;
272 ghm = 1ul << gh % maskbits;
273 }
274 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
275 } else {
276 if (!h) h = sysv_hash(s);
277 sym = sysv_lookup(s, h, dso);
278 }
279 if (!sym) continue;
280 if (!sym->st_shndx)
281 if (need_def || (sym->st_info&0xf) == STT_TLS
282 || ARCH_SYM_REJECT_UND(sym))
283 continue;
284 if (!sym->st_value)
285 if ((sym->st_info&0xf) != STT_TLS)
286 continue;
287 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
288 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
289
290 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
291 def.sym = sym;
292 def.dso = dso;
293 if (sym->st_info>>4 == STB_GLOBAL) break;
294 }
295 return def;
296 }
297
298 __attribute__((__visibility__("hidden")))
299 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
300
301 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
302 {
303 unsigned char *base = dso->base;
304 Sym *syms = dso->syms;
305 char *strings = dso->strings;
306 Sym *sym;
307 const char *name;
308 void *ctx;
309 int type;
310 int sym_index;
311 struct symdef def;
312 size_t *reloc_addr;
313 size_t sym_val;
314 size_t tls_val;
315 size_t addend;
316 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
317
318 if (dso == &ldso) {
319 /* Only ldso's REL table needs addend saving/reuse. */
320 if (rel == apply_addends_to)
321 reuse_addends = 1;
322 skip_relative = 1;
323 }
324
325 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
326 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
327 type = R_TYPE(rel[1]);
328 if (type == REL_NONE) continue;
329 sym_index = R_SYM(rel[1]);
330 reloc_addr = laddr(dso, rel[0]);
331 if (sym_index) {
332 sym = syms + sym_index;
333 name = strings + sym->st_name;
334 ctx = type==REL_COPY ? head->next : head;
335 def = (sym->st_info&0xf) == STT_SECTION
336 ? (struct symdef){ .dso = dso, .sym = sym }
337 : find_sym(ctx, name, type==REL_PLT);
338 if (!def.sym && (sym->st_shndx != SHN_UNDEF
339 || sym->st_info>>4 != STB_WEAK)) {
340 error("Error relocating %s: %s: symbol not found",
341 dso->name, name);
342 if (runtime) longjmp(*rtld_fail, 1);
343 continue;
344 }
345 } else {
346 sym = 0;
347 def.sym = 0;
348 def.dso = dso;
349 }
350
351 if (stride > 2) {
352 addend = rel[2];
353 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
354 addend = 0;
355 } else if (reuse_addends) {
356 /* Save original addend in stage 2 where the dso
357 * chain consists of just ldso; otherwise read back
358 * saved addend since the inline one was clobbered. */
359 if (head==&ldso)
360 saved_addends[save_slot] = *reloc_addr;
361 addend = saved_addends[save_slot++];
362 } else {
363 addend = *reloc_addr;
364 }
365
366 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
367 tls_val = def.sym ? def.sym->st_value : 0;
368
369 switch(type) {
370 case REL_NONE:
371 break;
372 case REL_OFFSET:
373 addend -= (size_t)reloc_addr;
374 case REL_SYMBOLIC:
375 case REL_GOT:
376 case REL_PLT:
377 *reloc_addr = sym_val + addend;
378 break;
379 case REL_RELATIVE:
380 *reloc_addr = (size_t)base + addend;
381 break;
382 case REL_SYM_OR_REL:
383 if (sym) *reloc_addr = sym_val + addend;
384 else *reloc_addr = (size_t)base + addend;
385 break;
386 case REL_COPY:
387 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
388 break;
389 case REL_OFFSET32:
390 *(uint32_t *)reloc_addr = sym_val + addend
391 - (size_t)reloc_addr;
392 break;
393 case REL_FUNCDESC:
394 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
395 + (def.sym - def.dso->syms)) : 0;
396 break;
397 case REL_FUNCDESC_VAL:
398 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
399 else *reloc_addr = sym_val;
400 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
401 break;
402 case REL_DTPMOD:
403 *reloc_addr = def.dso->tls_id;
404 break;
405 case REL_DTPOFF:
406 *reloc_addr = tls_val + addend - DTP_OFFSET;
407 break;
408 #ifdef TLS_ABOVE_TP
409 case REL_TPOFF:
410 *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
411 break;
412 #else
413 case REL_TPOFF:
414 *reloc_addr = tls_val - def.dso->tls.offset + addend;
415 break;
416 case REL_TPOFF_NEG:
417 *reloc_addr = def.dso->tls.offset - tls_val + addend;
418 break;
419 #endif
420 case REL_TLSDESC:
421 if (stride<3) addend = reloc_addr[1];
422 if (runtime && def.dso->tls_id >= static_tls_cnt) {
423 struct td_index *new = malloc(sizeof *new);
424 if (!new) {
425 error(
426 "Error relocating %s: cannot allocate TLSDESC for %s",
427 dso->name, sym ? name : "(local)" );
428 longjmp(*rtld_fail, 1);
429 }
430 new->next = dso->td_index;
431 dso->td_index = new;
432 new->args[0] = def.dso->tls_id;
433 new->args[1] = tls_val + addend;
434 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
435 reloc_addr[1] = (size_t)new;
436 } else {
437 reloc_addr[0] = (size_t)__tlsdesc_static;
438 #ifdef TLS_ABOVE_TP
439 reloc_addr[1] = tls_val + def.dso->tls.offset
440 + TPOFF_K + addend;
441 #else
442 reloc_addr[1] = tls_val - def.dso->tls.offset
443 + addend;
444 #endif
445 }
446 break;
447 default:
448 error("Error relocating %s: unsupported relocation type %d",
449 dso->name, type);
450 if (runtime) longjmp(*rtld_fail, 1);
451 continue;
452 }
453 }
454 }
455
456 /* A huge hack: to make up for the wastefulness of shared libraries
457 * needing at least a page of dirty memory even if they have no global
458 * data, we reclaim the gaps at the beginning and end of writable maps
459 * and "donate" them to the heap by setting up minimal malloc
460 * structures and then freeing them. */
461
462 static void reclaim(struct dso *dso, size_t start, size_t end)
463 {
464 size_t *a, *z;
465 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
466 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
467 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
468 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
469 if (start>end || end-start < 4*sizeof(size_t)) return;
470 a = laddr(dso, start);
471 z = laddr(dso, end);
472 a[-2] = 1;
473 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
474 z[1] = 1;
475 free(a);
476 }
477
478 static void reclaim_gaps(struct dso *dso)
479 {
480 Phdr *ph = dso->phdr;
481 size_t phcnt = dso->phnum;
482
483 if (DL_FDPIC) return; // FIXME
484 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
485 if (ph->p_type!=PT_LOAD) continue;
486 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
487 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
488 reclaim(dso, ph->p_vaddr+ph->p_memsz,
489 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
490 }
491 }
492
493 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
494 {
495 static int no_map_fixed;
496 char *q;
497 if (!no_map_fixed) {
498 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
499 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
500 return q;
501 no_map_fixed = 1;
502 }
503 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
504 if (flags & MAP_ANONYMOUS) {
505 memset(p, 0, n);
506 return p;
507 }
508 ssize_t r;
509 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
510 for (q=p; n; q+=r, off+=r, n-=r) {
511 r = read(fd, q, n);
512 if (r < 0 && errno != EINTR) return MAP_FAILED;
513 if (!r) {
514 memset(q, 0, n);
515 break;
516 }
517 }
518 return p;
519 }
520
521 static void unmap_library(struct dso *dso)
522 {
523 if (dso->loadmap) {
524 size_t i;
525 for (i=0; i<dso->loadmap->nsegs; i++) {
526 if (!dso->loadmap->segs[i].p_memsz)
527 continue;
528 munmap((void *)dso->loadmap->segs[i].addr,
529 dso->loadmap->segs[i].p_memsz);
530 }
531 free(dso->loadmap);
532 } else if (dso->map && dso->map_len) {
533 munmap(dso->map, dso->map_len);
534 }
535 }
536
537 static void *map_library(int fd, struct dso *dso)
538 {
539 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
540 void *allocated_buf=0;
541 size_t phsize;
542 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
543 size_t this_min, this_max;
544 size_t nsegs = 0;
545 off_t off_start;
546 Ehdr *eh;
547 Phdr *ph, *ph0;
548 unsigned prot;
549 unsigned char *map=MAP_FAILED, *base;
550 size_t dyn=0;
551 size_t tls_image=0;
552 size_t i;
553
554 ssize_t l = read(fd, buf, sizeof buf);
555 eh = buf;
556 if (l<0) return 0;
557 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
558 goto noexec;
559 phsize = eh->e_phentsize * eh->e_phnum;
560 if (phsize > sizeof buf - sizeof *eh) {
561 allocated_buf = malloc(phsize);
562 if (!allocated_buf) return 0;
563 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
564 if (l < 0) goto error;
565 if (l != phsize) goto noexec;
566 ph = ph0 = allocated_buf;
567 } else if (eh->e_phoff + phsize > l) {
568 l = pread(fd, buf+1, phsize, eh->e_phoff);
569 if (l < 0) goto error;
570 if (l != phsize) goto noexec;
571 ph = ph0 = (void *)(buf + 1);
572 } else {
573 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
574 }
575 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
576 if (ph->p_type == PT_DYNAMIC) {
577 dyn = ph->p_vaddr;
578 } else if (ph->p_type == PT_TLS) {
579 tls_image = ph->p_vaddr;
580 dso->tls.align = ph->p_align;
581 dso->tls.len = ph->p_filesz;
582 dso->tls.size = ph->p_memsz;
583 } else if (ph->p_type == PT_GNU_RELRO) {
584 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
585 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
586 }
587 if (ph->p_type != PT_LOAD) continue;
588 nsegs++;
589 if (ph->p_vaddr < addr_min) {
590 addr_min = ph->p_vaddr;
591 off_start = ph->p_offset;
592 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
593 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
594 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
595 }
596 if (ph->p_vaddr+ph->p_memsz > addr_max) {
597 addr_max = ph->p_vaddr+ph->p_memsz;
598 }
599 }
600 if (!dyn) goto noexec;
601 if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
602 dso->loadmap = calloc(1, sizeof *dso->loadmap
603 + nsegs * sizeof *dso->loadmap->segs);
604 if (!dso->loadmap) goto error;
605 dso->loadmap->nsegs = nsegs;
606 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
607 if (ph->p_type != PT_LOAD) continue;
608 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
609 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
610 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
611 map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
612 prot, MAP_PRIVATE,
613 fd, ph->p_offset & -PAGE_SIZE);
614 if (map == MAP_FAILED) {
615 unmap_library(dso);
616 goto error;
617 }
618 dso->loadmap->segs[i].addr = (size_t)map +
619 (ph->p_vaddr & PAGE_SIZE-1);
620 dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
621 dso->loadmap->segs[i].p_memsz = ph->p_memsz;
622 i++;
623 if (prot & PROT_WRITE) {
624 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
625 + ph->p_filesz;
626 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
627 size_t pgend = brk + ph->p_memsz - ph->p_filesz
628 + PAGE_SIZE-1 & -PAGE_SIZE;
629 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
630 pgend-pgbrk, prot,
631 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
632 -1, off_start) == MAP_FAILED)
633 goto error;
634 memset(map + brk, 0, pgbrk-brk);
635 }
636 }
637 map = (void *)dso->loadmap->segs[0].addr;
638 map_len = 0;
639 goto done_mapping;
640 }
641 addr_max += PAGE_SIZE-1;
642 addr_max &= -PAGE_SIZE;
643 addr_min &= -PAGE_SIZE;
644 off_start &= -PAGE_SIZE;
645 map_len = addr_max - addr_min + off_start;
646 /* The first time, we map too much, possibly even more than
647 * the length of the file. This is okay because we will not
648 * use the invalid part; we just need to reserve the right
649 * amount of virtual address space to map over later. */
650 map = DL_NOMMU_SUPPORT
651 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
652 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
653 : mmap((void *)addr_min, map_len, prot,
654 MAP_PRIVATE, fd, off_start);
655 if (map==MAP_FAILED) goto error;
656 dso->map = map;
657 dso->map_len = map_len;
658 /* If the loaded file is not relocatable and the requested address is
659 * not available, then the load operation must fail. */
660 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
661 errno = EBUSY;
662 goto error;
663 }
664 base = map - addr_min;
665 dso->phdr = 0;
666 dso->phnum = 0;
667 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
668 if (ph->p_type != PT_LOAD) continue;
669 /* Check if the programs headers are in this load segment, and
670 * if so, record the address for use by dl_iterate_phdr. */
671 if (!dso->phdr && eh->e_phoff >= ph->p_offset
672 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
673 dso->phdr = (void *)(base + ph->p_vaddr
674 + (eh->e_phoff-ph->p_offset));
675 dso->phnum = eh->e_phnum;
676 dso->phentsize = eh->e_phentsize;
677 }
678 /* Reuse the existing mapping for the lowest-address LOAD */
679 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
680 continue;
681 this_min = ph->p_vaddr & -PAGE_SIZE;
682 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
683 off_start = ph->p_offset & -PAGE_SIZE;
684 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
685 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
686 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
687 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
688 goto error;
689 if (ph->p_memsz > ph->p_filesz) {
690 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
691 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
692 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
693 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)
694 goto error;
695 }
696 }
697 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
698 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
699 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
700 && errno != ENOSYS)
701 goto error;
702 break;
703 }
704 done_mapping:
705 dso->base = base;
706 dso->dynv = laddr(dso, dyn);
707 if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
708 if (!runtime) reclaim_gaps(dso);
709 free(allocated_buf);
710 return map;
711 noexec:
712 errno = ENOEXEC;
713 error:
714 if (map!=MAP_FAILED) unmap_library(dso);
715 free(allocated_buf);
716 return 0;
717 }
718
719 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
720 {
721 size_t l;
722 int fd;
723 for (;;) {
724 s += strspn(s, ":\n");
725 l = strcspn(s, ":\n");
726 if (l-1 >= INT_MAX) return -1;
727 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
728 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
729 switch (errno) {
730 case ENOENT:
731 case ENOTDIR:
732 case EACCES:
733 case ENAMETOOLONG:
734 break;
735 default:
736 /* Any negative value but -1 will inhibit
737 * futher path search. */
738 return -2;
739 }
740 }
741 s += l;
742 }
743 }
744
745 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
746 {
747 size_t n, l;
748 const char *s, *t, *origin;
749 char *d;
750 if (p->rpath || !p->rpath_orig) return 0;
751 if (!strchr(p->rpath_orig, '$')) {
752 p->rpath = p->rpath_orig;
753 return 0;
754 }
755 n = 0;
756 s = p->rpath_orig;
757 while ((t=strchr(s, '$'))) {
758 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
759 return 0;
760 s = t+1;
761 n++;
762 }
763 if (n > SSIZE_MAX/PATH_MAX) return 0;
764
765 if (p->kernel_mapped) {
766 /* $ORIGIN searches cannot be performed for the main program
767 * when it is suid/sgid/AT_SECURE. This is because the
768 * pathname is under the control of the caller of execve.
769 * For libraries, however, $ORIGIN can be processed safely
770 * since the library's pathname came from a trusted source
771 * (either system paths or a call to dlopen). */
772 if (libc.secure)
773 return 0;
774 l = readlink("/proc/self/exe", buf, buf_size);
775 if (l == -1) switch (errno) {
776 case ENOENT:
777 case ENOTDIR:
778 case EACCES:
779 break;
780 default:
781 return -1;
782 }
783 if (l >= buf_size)
784 return 0;
785 buf[l] = 0;
786 origin = buf;
787 } else {
788 origin = p->name;
789 }
790 t = strrchr(origin, '/');
791 l = t ? t-origin : 0;
792 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
793 if (!p->rpath) return -1;
794
795 d = p->rpath;
796 s = p->rpath_orig;
797 while ((t=strchr(s, '$'))) {
798 memcpy(d, s, t-s);
799 d += t-s;
800 memcpy(d, origin, l);
801 d += l;
802 /* It was determined previously that the '$' is followed
803 * either by "ORIGIN" or "{ORIGIN}". */
804 s = t + 7 + 2*(t[1]=='{');
805 }
806 strcpy(d, s);
807 return 0;
808 }
809
810 static void decode_dyn(struct dso *p)
811 {
812 size_t dyn[DYN_CNT];
813 decode_vec(p->dynv, dyn, DYN_CNT);
814 p->syms = laddr(p, dyn[DT_SYMTAB]);
815 p->strings = laddr(p, dyn[DT_STRTAB]);
816 if (dyn[0]&(1<<DT_HASH))
817 p->hashtab = laddr(p, dyn[DT_HASH]);
818 if (dyn[0]&(1<<DT_RPATH))
819 p->rpath_orig = p->strings + dyn[DT_RPATH];
820 if (dyn[0]&(1<<DT_RUNPATH))
821 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
822 if (dyn[0]&(1<<DT_PLTGOT))
823 p->got = laddr(p, dyn[DT_PLTGOT]);
824 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
825 p->ghashtab = laddr(p, *dyn);
826 if (search_vec(p->dynv, dyn, DT_VERSYM))
827 p->versym = laddr(p, *dyn);
828 }
829
830 static size_t count_syms(struct dso *p)
831 {
832 if (p->hashtab) return p->hashtab[1];
833
834 size_t nsym, i;
835 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
836 uint32_t *hashval;
837 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
838 if (buckets[i] > nsym)
839 nsym = buckets[i];
840 }
841 if (nsym) {
842 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
843 do nsym++;
844 while (!(*hashval++ & 1));
845 }
846 return nsym;
847 }
848
849 static void *dl_mmap(size_t n)
850 {
851 void *p;
852 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
853 #ifdef SYS_mmap2
854 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
855 #else
856 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
857 #endif
858 return p == MAP_FAILED ? 0 : p;
859 }
860
861 static void makefuncdescs(struct dso *p)
862 {
863 static int self_done;
864 size_t nsym = count_syms(p);
865 size_t i, size = nsym * sizeof(*p->funcdescs);
866
867 if (!self_done) {
868 p->funcdescs = dl_mmap(size);
869 self_done = 1;
870 } else {
871 p->funcdescs = malloc(size);
872 }
873 if (!p->funcdescs) {
874 if (!runtime) a_crash();
875 error("Error allocating function descriptors for %s", p->name);
876 longjmp(*rtld_fail, 1);
877 }
878 for (i=0; i<nsym; i++) {
879 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
880 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
881 p->funcdescs[i].got = p->got;
882 } else {
883 p->funcdescs[i].addr = 0;
884 p->funcdescs[i].got = 0;
885 }
886 }
887 }
888
889 static struct dso *load_library(const char *name, struct dso *needed_by)
890 {
891 char buf[2*NAME_MAX+2];
892 const char *pathname;
893 unsigned char *map;
894 struct dso *p, temp_dso = {0};
895 int fd;
896 struct stat st;
897 size_t alloc_size;
898 int n_th = 0;
899 int is_self = 0;
900
901 if (!*name) {
902 errno = EINVAL;
903 return 0;
904 }
905
906 /* Catch and block attempts to reload the implementation itself */
907 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
908 static const char reserved[] =
909 "c.pthread.rt.m.dl.util.xnet.";
910 const char *rp, *next;
911 for (rp=reserved; *rp; rp=next) {
912 next = strchr(rp, '.') + 1;
913 if (strncmp(name+3, rp, next-rp) == 0)
914 break;
915 }
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 if (!strcmp(name, ldso.name)) is_self = 1;
933 if (is_self) {
934 if (!ldso.prev) {
935 tail->next = &ldso;
936 ldso.prev = tail;
937 tail = ldso.next ? ldso.next : &ldso;
938 }
939 return &ldso;
940 }
941 if (strchr(name, '/')) {
942 pathname = name;
943 fd = open(name, O_RDONLY|O_CLOEXEC);
944 } else {
945 /* Search for the name to see if it's already loaded */
946 for (p=head->next; p; p=p->next) {
947 if (p->shortname && !strcmp(p->shortname, name)) {
948 p->refcnt++;
949 return p;
950 }
951 }
952 if (strlen(name) > NAME_MAX) return 0;
953 fd = -1;
954 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
955 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
956 if (fixup_rpath(p, buf, sizeof buf) < 0)
957 fd = -2; /* Inhibit further search. */
958 if (p->rpath)
959 fd = path_open(name, p->rpath, buf, sizeof buf);
960 }
961 if (fd == -1) {
962 if (!sys_path) {
963 char *prefix = 0;
964 size_t prefix_len;
965 if (ldso.name[0]=='/') {
966 char *s, *t, *z;
967 for (s=t=z=ldso.name; *s; s++)
968 if (*s=='/') z=t, t=s;
969 prefix_len = z-ldso.name;
970 if (prefix_len < PATH_MAX)
971 prefix = ldso.name;
972 }
973 if (!prefix) {
974 prefix = "";
975 prefix_len = 0;
976 }
977 char etc_ldso_path[prefix_len + 1
978 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
979 snprintf(etc_ldso_path, sizeof etc_ldso_path,
980 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
981 (int)prefix_len, prefix);
982 FILE *f = fopen(etc_ldso_path, "rbe");
983 if (f) {
984 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
985 free(sys_path);
986 sys_path = "";
987 }
988 fclose(f);
989 } else if (errno != ENOENT) {
990 sys_path = "";
991 }
992 }
993 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
994 fd = path_open(name, sys_path, buf, sizeof buf);
995 }
996 pathname = buf;
997 }
998 if (fd < 0) return 0;
999 if (fstat(fd, &st) < 0) {
1000 close(fd);
1001 return 0;
1002 }
1003 for (p=head->next; p; p=p->next) {
1004 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1005 /* If this library was previously loaded with a
1006 * pathname but a search found the same inode,
1007 * setup its shortname so it can be found by name. */
1008 if (!p->shortname && pathname != name)
1009 p->shortname = strrchr(p->name, '/')+1;
1010 close(fd);
1011 p->refcnt++;
1012 return p;
1013 }
1014 }
1015 map = noload ? 0 : map_library(fd, &temp_dso);
1016 close(fd);
1017 if (!map) return 0;
1018
1019 /* Allocate storage for the new DSO. When there is TLS, this
1020 * storage must include a reservation for all pre-existing
1021 * threads to obtain copies of both the new TLS, and an
1022 * extended DTV capable of storing an additional slot for
1023 * the newly-loaded DSO. */
1024 alloc_size = sizeof *p + strlen(pathname) + 1;
1025 if (runtime && temp_dso.tls.image) {
1026 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1027 + sizeof(void *) * (tls_cnt+3);
1028 n_th = libc.threads_minus_1 + 1;
1029 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1030 else alloc_size += n_th * per_th;
1031 }
1032 p = calloc(1, alloc_size);
1033 if (!p) {
1034 unmap_library(&temp_dso);
1035 return 0;
1036 }
1037 memcpy(p, &temp_dso, sizeof temp_dso);
1038 decode_dyn(p);
1039 p->dev = st.st_dev;
1040 p->ino = st.st_ino;
1041 p->refcnt = 1;
1042 p->needed_by = needed_by;
1043 p->name = p->buf;
1044 strcpy(p->name, pathname);
1045 /* Add a shortname only if name arg was not an explicit pathname. */
1046 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1047 if (p->tls.image) {
1048 p->tls_id = ++tls_cnt;
1049 tls_align = MAXP2(tls_align, p->tls.align);
1050 #ifdef TLS_ABOVE_TP
1051 p->tls.offset = tls_offset + ( (tls_align-1) &
1052 -(tls_offset + (uintptr_t)p->tls.image) );
1053 tls_offset += p->tls.size;
1054 #else
1055 tls_offset += p->tls.size + p->tls.align - 1;
1056 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1057 & (p->tls.align-1);
1058 p->tls.offset = tls_offset;
1059 #endif
1060 p->new_dtv = (void *)(-sizeof(size_t) &
1061 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1062 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1063 if (tls_tail) tls_tail->next = &p->tls;
1064 else libc.tls_head = &p->tls;
1065 tls_tail = &p->tls;
1066 }
1067
1068 tail->next = p;
1069 p->prev = tail;
1070 tail = p;
1071
1072 if (DL_FDPIC) makefuncdescs(p);
1073
1074 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1075
1076 return p;
1077 }
1078
1079 static void load_deps(struct dso *p)
1080 {
1081 size_t i, ndeps=0;
1082 struct dso ***deps = &p->deps, **tmp, *dep;
1083 for (; p; p=p->next) {
1084 for (i=0; p->dynv[i]; i+=2) {
1085 if (p->dynv[i] != DT_NEEDED) continue;
1086 dep = load_library(p->strings + p->dynv[i+1], p);
1087 if (!dep) {
1088 error("Error loading shared library %s: %m (needed by %s)",
1089 p->strings + p->dynv[i+1], p->name);
1090 if (runtime) longjmp(*rtld_fail, 1);
1091 continue;
1092 }
1093 if (runtime) {
1094 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1095 if (!tmp) longjmp(*rtld_fail, 1);
1096 tmp[ndeps++] = dep;
1097 tmp[ndeps] = 0;
1098 *deps = tmp;
1099 }
1100 }
1101 }
1102 }
1103
1104 static void load_preload(char *s)
1105 {
1106 int tmp;
1107 char *z;
1108 for (z=s; *z; s=z) {
1109 for ( ; *s && (isspace(*s) || *s==':'); s++);
1110 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1111 tmp = *z;
1112 *z = 0;
1113 load_library(s, 0);
1114 *z = tmp;
1115 }
1116 }
1117
1118 static void make_global(struct dso *p)
1119 {
1120 for (; p; p=p->next) p->global = 1;
1121 }
1122
1123 static void do_mips_relocs(struct dso *p, size_t *got)
1124 {
1125 size_t i, j, rel[2];
1126 unsigned char *base = p->base;
1127 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1128 if (p==&ldso) {
1129 got += i;
1130 } else {
1131 while (i--) *got++ += (size_t)base;
1132 }
1133 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1134 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1135 Sym *sym = p->syms + j;
1136 rel[0] = (unsigned char *)got - base;
1137 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1138 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1139 do_relocs(p, rel, sizeof rel, 2);
1140 }
1141 }
1142
1143 static void reloc_all(struct dso *p)
1144 {
1145 size_t dyn[DYN_CNT];
1146 for (; p; p=p->next) {
1147 if (p->relocated) continue;
1148 decode_vec(p->dynv, dyn, DYN_CNT);
1149 if (NEED_MIPS_GOT_RELOCS)
1150 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1151 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1152 2+(dyn[DT_PLTREL]==DT_RELA));
1153 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1154 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1155
1156 if (head != &ldso && p->relro_start != p->relro_end &&
1157 mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1158 && errno != ENOSYS) {
1159 error("Error relocating %s: RELRO protection failed: %m",
1160 p->name);
1161 if (runtime) longjmp(*rtld_fail, 1);
1162 }
1163
1164 p->relocated = 1;
1165 }
1166 }
1167
1168 static void kernel_mapped_dso(struct dso *p)
1169 {
1170 size_t min_addr = -1, max_addr = 0, cnt;
1171 Phdr *ph = p->phdr;
1172 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1173 if (ph->p_type == PT_DYNAMIC) {
1174 p->dynv = laddr(p, ph->p_vaddr);
1175 } else if (ph->p_type == PT_GNU_RELRO) {
1176 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1177 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1178 }
1179 if (ph->p_type != PT_LOAD) continue;
1180 if (ph->p_vaddr < min_addr)
1181 min_addr = ph->p_vaddr;
1182 if (ph->p_vaddr+ph->p_memsz > max_addr)
1183 max_addr = ph->p_vaddr+ph->p_memsz;
1184 }
1185 min_addr &= -PAGE_SIZE;
1186 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1187 p->map = p->base + min_addr;
1188 p->map_len = max_addr - min_addr;
1189 p->kernel_mapped = 1;
1190 }
1191
1192 void __libc_exit_fini()
1193 {
1194 struct dso *p;
1195 size_t dyn[DYN_CNT];
1196 for (p=fini_head; p; p=p->fini_next) {
1197 if (!p->constructed) continue;
1198 decode_vec(p->dynv, dyn, DYN_CNT);
1199 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1200 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1201 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1202 while (n--) ((void (*)(void))*--fn)();
1203 }
1204 #ifndef NO_LEGACY_INITFINI
1205 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1206 fpaddr(p, dyn[DT_FINI])();
1207 #endif
1208 }
1209 }
1210
1211 static void do_init_fini(struct dso *p)
1212 {
1213 size_t dyn[DYN_CNT];
1214 int need_locking = libc.threads_minus_1;
1215 /* Allow recursive calls that arise when a library calls
1216 * dlopen from one of its constructors, but block any
1217 * other threads until all ctors have finished. */
1218 if (need_locking) pthread_mutex_lock(&init_fini_lock);
1219 for (; p; p=p->prev) {
1220 if (p->constructed) continue;
1221 p->constructed = 1;
1222 decode_vec(p->dynv, dyn, DYN_CNT);
1223 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1224 p->fini_next = fini_head;
1225 fini_head = p;
1226 }
1227 #ifndef NO_LEGACY_INITFINI
1228 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1229 fpaddr(p, dyn[DT_INIT])();
1230 #endif
1231 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1232 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1233 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1234 while (n--) ((void (*)(void))*fn++)();
1235 }
1236 if (!need_locking && libc.threads_minus_1) {
1237 need_locking = 1;
1238 pthread_mutex_lock(&init_fini_lock);
1239 }
1240 }
1241 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1242 }
1243
1244 void __libc_start_init(void)
1245 {
1246 do_init_fini(tail);
1247 }
1248
1249 static void dl_debug_state(void)
1250 {
1251 }
1252
1253 weak_alias(dl_debug_state, _dl_debug_state);
1254
1255 void __init_tls(size_t *auxv)
1256 {
1257 }
1258
1259 __attribute__((__visibility__("hidden")))
1260 void *__tls_get_new(tls_mod_off_t *v)
1261 {
1262 pthread_t self = __pthread_self();
1263
1264 /* Block signals to make accessing new TLS async-signal-safe */
1265 sigset_t set;
1266 __block_all_sigs(&set);
1267 if (v[0]<=(size_t)self->dtv[0]) {
1268 __restore_sigs(&set);
1269 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1270 }
1271
1272 /* This is safe without any locks held because, if the caller
1273 * is able to request the Nth entry of the DTV, the DSO list
1274 * must be valid at least that far out and it was synchronized
1275 * at program startup or by an already-completed call to dlopen. */
1276 struct dso *p;
1277 for (p=head; p->tls_id != v[0]; p=p->next);
1278
1279 /* Get new DTV space from new DSO if needed */
1280 if (v[0] > (size_t)self->dtv[0]) {
1281 void **newdtv = p->new_dtv +
1282 (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1283 memcpy(newdtv, self->dtv,
1284 ((size_t)self->dtv[0]+1) * sizeof(void *));
1285 newdtv[0] = (void *)v[0];
1286 self->dtv = self->dtv_copy = newdtv;
1287 }
1288
1289 /* Get new TLS memory from all new DSOs up to the requested one */
1290 unsigned char *mem;
1291 for (p=head; ; p=p->next) {
1292 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1293 mem = p->new_tls + (p->tls.size + p->tls.align)
1294 * a_fetch_add(&p->new_tls_idx,1);
1295 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1296 & (p->tls.align-1);
1297 self->dtv[p->tls_id] = mem;
1298 memcpy(mem, p->tls.image, p->tls.len);
1299 if (p->tls_id == v[0]) break;
1300 }
1301 __restore_sigs(&set);
1302 return mem + v[1] + DTP_OFFSET;
1303 }
1304
1305 static void update_tls_size()
1306 {
1307 libc.tls_cnt = tls_cnt;
1308 libc.tls_align = tls_align;
1309 libc.tls_size = ALIGN(
1310 (1+tls_cnt) * sizeof(void *) +
1311 tls_offset +
1312 sizeof(struct pthread) +
1313 tls_align * 2,
1314 tls_align);
1315 }
1316
1317 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1318 * following stage 2 and stage 3 functions via primitive symbolic lookup
1319 * since it does not have access to their addresses to begin with. */
1320
1321 /* Stage 2 of the dynamic linker is called after relative relocations
1322 * have been processed. It can make function calls to static functions
1323 * and access string literals and static data, but cannot use extern
1324 * symbols. Its job is to perform symbolic relocations on the dynamic
1325 * linker itself, but some of the relocations performed may need to be
1326 * replaced later due to copy relocations in the main program. */
1327
1328 __attribute__((__visibility__("hidden")))
1329 void __dls2(unsigned char *base, size_t *sp)
1330 {
1331 if (DL_FDPIC) {
1332 void *p1 = (void *)sp[-2];
1333 void *p2 = (void *)sp[-1];
1334 if (!p1) {
1335 size_t *auxv, aux[AUX_CNT];
1336 for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1337 decode_vec(auxv, aux, AUX_CNT);
1338 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1339 else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1340 }
1341 app_loadmap = p2 ? p1 : 0;
1342 ldso.loadmap = p2 ? p2 : p1;
1343 ldso.base = laddr(&ldso, 0);
1344 } else {
1345 ldso.base = base;
1346 }
1347 Ehdr *ehdr = (void *)ldso.base;
1348 ldso.name = ldso.shortname = "libc.so";
1349 ldso.global = 1;
1350 ldso.phnum = ehdr->e_phnum;
1351 ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1352 ldso.phentsize = ehdr->e_phentsize;
1353 kernel_mapped_dso(&ldso);
1354 decode_dyn(&ldso);
1355
1356 if (DL_FDPIC) makefuncdescs(&ldso);
1357
1358 /* Prepare storage for to save clobbered REL addends so they
1359 * can be reused in stage 3. There should be very few. If
1360 * something goes wrong and there are a huge number, abort
1361 * instead of risking stack overflow. */
1362 size_t dyn[DYN_CNT];
1363 decode_vec(ldso.dynv, dyn, DYN_CNT);
1364 size_t *rel = laddr(&ldso, dyn[DT_REL]);
1365 size_t rel_size = dyn[DT_RELSZ];
1366 size_t symbolic_rel_cnt = 0;
1367 apply_addends_to = rel;
1368 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1369 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1370 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1371 size_t addends[symbolic_rel_cnt+1];
1372 saved_addends = addends;
1373
1374 head = &ldso;
1375 reloc_all(&ldso);
1376
1377 ldso.relocated = 0;
1378
1379 /* Call dynamic linker stage-3, __dls3, looking it up
1380 * symbolically as a barrier against moving the address
1381 * load across the above relocation processing. */
1382 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1383 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1384 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1385 }
1386
1387 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1388 * fully functional. Its job is to load (if not already loaded) and
1389 * process dependencies and relocations for the main application and
1390 * transfer control to its entry point. */
1391
1392 _Noreturn void __dls3(size_t *sp)
1393 {
1394 static struct dso app, vdso;
1395 size_t aux[AUX_CNT], *auxv;
1396 size_t i;
1397 char *env_preload=0;
1398 size_t vdso_base;
1399 int argc = *sp;
1400 char **argv = (void *)(sp+1);
1401 char **argv_orig = argv;
1402 char **envp = argv+argc+1;
1403
1404 /* Find aux vector just past environ[] and use it to initialize
1405 * global data that may be needed before we can make syscalls. */
1406 __environ = envp;
1407 for (i=argc+1; argv[i]; i++);
1408 libc.auxv = auxv = (void *)(argv+i+1);
1409 decode_vec(auxv, aux, AUX_CNT);
1410 __hwcap = aux[AT_HWCAP];
1411 libc.page_size = aux[AT_PAGESZ];
1412 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1413 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1414
1415 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1416 * use during dynamic linking. If possible it will also serve as the
1417 * thread pointer at runtime. */
1418 libc.tls_size = sizeof builtin_tls;
1419 libc.tls_align = tls_align;
1420 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1421 a_crash();
1422 }
1423
1424 /* Only trust user/env if kernel says we're not suid/sgid */
1425 if (!libc.secure) {
1426 env_path = getenv("LD_LIBRARY_PATH");
1427 env_preload = getenv("LD_PRELOAD");
1428 }
1429
1430 /* If the main program was already loaded by the kernel,
1431 * AT_PHDR will point to some location other than the dynamic
1432 * linker's program headers. */
1433 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1434 size_t interp_off = 0;
1435 size_t tls_image = 0;
1436 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1437 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1438 app.phnum = aux[AT_PHNUM];
1439 app.phentsize = aux[AT_PHENT];
1440 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1441 if (phdr->p_type == PT_PHDR)
1442 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1443 else if (phdr->p_type == PT_INTERP)
1444 interp_off = (size_t)phdr->p_vaddr;
1445 else if (phdr->p_type == PT_TLS) {
1446 tls_image = phdr->p_vaddr;
1447 app.tls.len = phdr->p_filesz;
1448 app.tls.size = phdr->p_memsz;
1449 app.tls.align = phdr->p_align;
1450 }
1451 }
1452 if (DL_FDPIC) app.loadmap = app_loadmap;
1453 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1454 if (interp_off) ldso.name = laddr(&app, interp_off);
1455 if ((aux[0] & (1UL<<AT_EXECFN))
1456 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1457 app.name = (char *)aux[AT_EXECFN];
1458 else
1459 app.name = argv[0];
1460 kernel_mapped_dso(&app);
1461 } else {
1462 int fd;
1463 char *ldname = argv[0];
1464 size_t l = strlen(ldname);
1465 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1466 argv++;
1467 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1468 char *opt = argv[0]+2;
1469 *argv++ = (void *)-1;
1470 if (!*opt) {
1471 break;
1472 } else if (!memcmp(opt, "list", 5)) {
1473 ldd_mode = 1;
1474 } else if (!memcmp(opt, "library-path", 12)) {
1475 if (opt[12]=='=') env_path = opt+13;
1476 else if (opt[12]) *argv = 0;
1477 else if (*argv) env_path = *argv++;
1478 } else if (!memcmp(opt, "preload", 7)) {
1479 if (opt[7]=='=') env_preload = opt+8;
1480 else if (opt[7]) *argv = 0;
1481 else if (*argv) env_preload = *argv++;
1482 } else {
1483 argv[0] = 0;
1484 }
1485 }
1486 argv[-1] = (void *)(argc - (argv-argv_orig));
1487 if (!argv[0]) {
1488 dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1489 "Version %s\n"
1490 "Dynamic Program Loader\n"
1491 "Usage: %s [options] [--] pathname%s\n",
1492 __libc_get_version(), ldname,
1493 ldd_mode ? "" : " [args]");
1494 _exit(1);
1495 }
1496 fd = open(argv[0], O_RDONLY);
1497 if (fd < 0) {
1498 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1499 _exit(1);
1500 }
1501 runtime = 1;
1502 Ehdr *ehdr = (void *)map_library(fd, &app);
1503 if (!ehdr) {
1504 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1505 _exit(1);
1506 }
1507 runtime = 0;
1508 close(fd);
1509 ldso.name = ldname;
1510 app.name = argv[0];
1511 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1512 /* Find the name that would have been used for the dynamic
1513 * linker had ldd not taken its place. */
1514 if (ldd_mode) {
1515 for (i=0; i<app.phnum; i++) {
1516 if (app.phdr[i].p_type == PT_INTERP)
1517 ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1518 }
1519 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1520 }
1521 }
1522 if (app.tls.size) {
1523 libc.tls_head = tls_tail = &app.tls;
1524 app.tls_id = tls_cnt = 1;
1525 #ifdef TLS_ABOVE_TP
1526 app.tls.offset = 0;
1527 tls_offset = app.tls.size
1528 + ( -((uintptr_t)app.tls.image + app.tls.size)
1529 & (app.tls.align-1) );
1530 #else
1531 tls_offset = app.tls.offset = app.tls.size
1532 + ( -((uintptr_t)app.tls.image + app.tls.size)
1533 & (app.tls.align-1) );
1534 #endif
1535 tls_align = MAXP2(tls_align, app.tls.align);
1536 }
1537 app.global = 1;
1538 decode_dyn(&app);
1539 if (DL_FDPIC) {
1540 makefuncdescs(&app);
1541 if (!app.loadmap) {
1542 app.loadmap = (void *)&app_dummy_loadmap;
1543 app.loadmap->nsegs = 1;
1544 app.loadmap->segs[0].addr = (size_t)app.map;
1545 app.loadmap->segs[0].p_vaddr = (size_t)app.map
1546 - (size_t)app.base;
1547 app.loadmap->segs[0].p_memsz = app.map_len;
1548 }
1549 argv[-3] = (void *)app.loadmap;
1550 }
1551
1552 /* Attach to vdso, if provided by the kernel */
1553 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1554 Ehdr *ehdr = (void *)vdso_base;
1555 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1556 vdso.phnum = ehdr->e_phnum;
1557 vdso.phentsize = ehdr->e_phentsize;
1558 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1559 if (phdr->p_type == PT_DYNAMIC)
1560 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1561 if (phdr->p_type == PT_LOAD)
1562 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1563 }
1564 vdso.name = "";
1565 vdso.shortname = "linux-gate.so.1";
1566 vdso.global = 1;
1567 vdso.relocated = 1;
1568 decode_dyn(&vdso);
1569 vdso.prev = &ldso;
1570 ldso.next = &vdso;
1571 }
1572
1573 /* Initial dso chain consists only of the app. */
1574 head = tail = &app;
1575
1576 /* Donate unused parts of app and library mapping to malloc */
1577 reclaim_gaps(&app);
1578 reclaim_gaps(&ldso);
1579
1580 /* Load preload/needed libraries, add their symbols to the global
1581 * namespace, and perform all remaining relocations. */
1582 if (env_preload) load_preload(env_preload);
1583 load_deps(&app);
1584 make_global(&app);
1585
1586 for (i=0; app.dynv[i]; i+=2) {
1587 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1588 app.dynv[i+1] = (size_t)&debug;
1589 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1590 size_t *ptr = (size_t *) app.dynv[i+1];
1591 *ptr = (size_t)&debug;
1592 }
1593 }
1594
1595 /* The main program must be relocated LAST since it may contin
1596 * copy relocations which depend on libraries' relocations. */
1597 reloc_all(app.next);
1598 reloc_all(&app);
1599
1600 update_tls_size();
1601 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1602 void *initial_tls = calloc(libc.tls_size, 1);
1603 if (!initial_tls) {
1604 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1605 argv[0], libc.tls_size);
1606 _exit(127);
1607 }
1608 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1609 a_crash();
1610 }
1611 } else {
1612 size_t tmp_tls_size = libc.tls_size;
1613 pthread_t self = __pthread_self();
1614 /* Temporarily set the tls size to the full size of
1615 * builtin_tls so that __copy_tls will use the same layout
1616 * as it did for before. Then check, just to be safe. */
1617 libc.tls_size = sizeof builtin_tls;
1618 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1619 libc.tls_size = tmp_tls_size;
1620 }
1621 static_tls_cnt = tls_cnt;
1622
1623 if (ldso_fail) _exit(127);
1624 if (ldd_mode) _exit(0);
1625
1626 /* Switch to runtime mode: any further failures in the dynamic
1627 * linker are a reportable failure rather than a fatal startup
1628 * error. */
1629 runtime = 1;
1630
1631 debug.ver = 1;
1632 debug.bp = dl_debug_state;
1633 debug.head = head;
1634 debug.base = ldso.base;
1635 debug.state = 0;
1636 _dl_debug_state();
1637
1638 errno = 0;
1639
1640 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1641 for(;;);
1642 }
1643
1644 void *dlopen(const char *file, int mode)
1645 {
1646 struct dso *volatile p, *orig_tail, *next;
1647 struct tls_module *orig_tls_tail;
1648 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1649 size_t i;
1650 int cs;
1651 jmp_buf jb;
1652
1653 if (!file) return head;
1654
1655 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1656 pthread_rwlock_wrlock(&lock);
1657 __inhibit_ptc();
1658
1659 p = 0;
1660 orig_tls_tail = tls_tail;
1661 orig_tls_cnt = tls_cnt;
1662 orig_tls_offset = tls_offset;
1663 orig_tls_align = tls_align;
1664 orig_tail = tail;
1665 noload = mode & RTLD_NOLOAD;
1666
1667 rtld_fail = &jb;
1668 if (setjmp(*rtld_fail)) {
1669 /* Clean up anything new that was (partially) loaded */
1670 if (p && p->deps) for (i=0; p->deps[i]; i++)
1671 if (p->deps[i]->global < 0)
1672 p->deps[i]->global = 0;
1673 for (p=orig_tail->next; p; p=next) {
1674 next = p->next;
1675 while (p->td_index) {
1676 void *tmp = p->td_index->next;
1677 free(p->td_index);
1678 p->td_index = tmp;
1679 }
1680 free(p->funcdescs);
1681 if (p->rpath != p->rpath_orig)
1682 free(p->rpath);
1683 free(p->deps);
1684 unmap_library(p);
1685 free(p);
1686 }
1687 if (!orig_tls_tail) libc.tls_head = 0;
1688 tls_tail = orig_tls_tail;
1689 if (tls_tail) tls_tail->next = 0;
1690 tls_cnt = orig_tls_cnt;
1691 tls_offset = orig_tls_offset;
1692 tls_align = orig_tls_align;
1693 tail = orig_tail;
1694 tail->next = 0;
1695 p = 0;
1696 goto end;
1697 } else p = load_library(file, head);
1698
1699 if (!p) {
1700 error(noload ?
1701 "Library %s is not already loaded" :
1702 "Error loading shared library %s: %m",
1703 file);
1704 goto end;
1705 }
1706
1707 /* First load handling */
1708 if (!p->deps) {
1709 load_deps(p);
1710 if (p->deps) for (i=0; p->deps[i]; i++)
1711 if (!p->deps[i]->global)
1712 p->deps[i]->global = -1;
1713 if (!p->global) p->global = -1;
1714 reloc_all(p);
1715 if (p->deps) for (i=0; p->deps[i]; i++)
1716 if (p->deps[i]->global < 0)
1717 p->deps[i]->global = 0;
1718 if (p->global < 0) p->global = 0;
1719 }
1720
1721 if (mode & RTLD_GLOBAL) {
1722 if (p->deps) for (i=0; p->deps[i]; i++)
1723 p->deps[i]->global = 1;
1724 p->global = 1;
1725 }
1726
1727 update_tls_size();
1728 _dl_debug_state();
1729 orig_tail = tail;
1730 end:
1731 __release_ptc();
1732 if (p) gencnt++;
1733 pthread_rwlock_unlock(&lock);
1734 if (p) do_init_fini(orig_tail);
1735 pthread_setcancelstate(cs, 0);
1736 return p;
1737 }
1738
1739 __attribute__((__visibility__("hidden")))
1740 int __dl_invalid_handle(void *h)
1741 {
1742 struct dso *p;
1743 for (p=head; p; p=p->next) if (h==p) return 0;
1744 error("Invalid library handle %p", (void *)h);
1745 return 1;
1746 }
1747
1748 static void *addr2dso(size_t a)
1749 {
1750 struct dso *p;
1751 size_t i;
1752 if (DL_FDPIC) for (p=head; p; p=p->next) {
1753 i = count_syms(p);
1754 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1755 return p;
1756 }
1757 for (p=head; p; p=p->next) {
1758 if (DL_FDPIC && p->loadmap) {
1759 for (i=0; i<p->loadmap->nsegs; i++) {
1760 if (a-p->loadmap->segs[i].p_vaddr
1761 < p->loadmap->segs[i].p_memsz)
1762 return p;
1763 }
1764 } else {
1765 if (a-(size_t)p->map < p->map_len)
1766 return p;
1767 }
1768 }
1769 return 0;
1770 }
1771
1772 void *__tls_get_addr(tls_mod_off_t *);
1773
1774 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1775 {
1776 size_t i;
1777 uint32_t h = 0, gh = 0, *ght;
1778 Sym *sym;
1779 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1780 if (p == RTLD_DEFAULT) {
1781 p = head;
1782 } else if (p == RTLD_NEXT) {
1783 p = addr2dso((size_t)ra);
1784 if (!p) p=head;
1785 p = p->next;
1786 }
1787 struct symdef def = find_sym(p, s, 0);
1788 if (!def.sym) goto failed;
1789 if ((def.sym->st_info&0xf) == STT_TLS)
1790 return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
1791 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1792 return def.dso->funcdescs + (def.sym - def.dso->syms);
1793 return laddr(def.dso, def.sym->st_value);
1794 }
1795 if (__dl_invalid_handle(p))
1796 return 0;
1797 if ((ght = p->ghashtab)) {
1798 gh = gnu_hash(s);
1799 sym = gnu_lookup(gh, ght, p, s);
1800 } else {
1801 h = sysv_hash(s);
1802 sym = sysv_lookup(s, h, p);
1803 }
1804 if (sym && (sym->st_info&0xf) == STT_TLS)
1805 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
1806 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1807 return p->funcdescs + (sym - p->syms);
1808 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1809 return laddr(p, sym->st_value);
1810 if (p->deps) for (i=0; p->deps[i]; i++) {
1811 if ((ght = p->deps[i]->ghashtab)) {
1812 if (!gh) gh = gnu_hash(s);
1813 sym = gnu_lookup(gh, ght, p->deps[i], s);
1814 } else {
1815 if (!h) h = sysv_hash(s);
1816 sym = sysv_lookup(s, h, p->deps[i]);
1817 }
1818 if (sym && (sym->st_info&0xf) == STT_TLS)
1819 return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
1820 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1821 return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1822 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1823 return laddr(p->deps[i], sym->st_value);
1824 }
1825 failed:
1826 error("Symbol not found: %s", s);
1827 return 0;
1828 }
1829
1830 int dladdr(const void *addr, Dl_info *info)
1831 {
1832 struct dso *p;
1833 Sym *sym, *bestsym;
1834 uint32_t nsym;
1835 char *strings;
1836 void *best = 0;
1837
1838 pthread_rwlock_rdlock(&lock);
1839 p = addr2dso((size_t)addr);
1840 pthread_rwlock_unlock(&lock);
1841
1842 if (!p) return 0;
1843
1844 sym = p->syms;
1845 strings = p->strings;
1846 nsym = count_syms(p);
1847
1848 if (DL_FDPIC) {
1849 size_t idx = ((size_t)addr-(size_t)p->funcdescs)
1850 / sizeof(*p->funcdescs);
1851 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1852 best = p->funcdescs + idx;
1853 bestsym = sym + idx;
1854 }
1855 }
1856
1857 if (!best) for (; nsym; nsym--, sym++) {
1858 if (sym->st_value
1859 && (1<<(sym->st_info&0xf) & OK_TYPES)
1860 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1861 void *symaddr = laddr(p, sym->st_value);
1862 if (symaddr > addr || symaddr < best)
1863 continue;
1864 best = symaddr;
1865 bestsym = sym;
1866 if (addr == symaddr)
1867 break;
1868 }
1869 }
1870
1871 if (!best) return 0;
1872
1873 if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
1874 best = p->funcdescs + (bestsym - p->syms);
1875
1876 info->dli_fname = p->name;
1877 info->dli_fbase = p->base;
1878 info->dli_sname = strings + bestsym->st_name;
1879 info->dli_saddr = best;
1880
1881 return 1;
1882 }
1883
1884 __attribute__((__visibility__("hidden")))
1885 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1886 {
1887 void *res;
1888 pthread_rwlock_rdlock(&lock);
1889 res = do_dlsym(p, s, ra);
1890 pthread_rwlock_unlock(&lock);
1891 return res;
1892 }
1893
1894 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1895 {
1896 struct dso *current;
1897 struct dl_phdr_info info;
1898 int ret = 0;
1899 for(current = head; current;) {
1900 info.dlpi_addr = (uintptr_t)current->base;
1901 info.dlpi_name = current->name;
1902 info.dlpi_phdr = current->phdr;
1903 info.dlpi_phnum = current->phnum;
1904 info.dlpi_adds = gencnt;
1905 info.dlpi_subs = 0;
1906 info.dlpi_tls_modid = current->tls_id;
1907 info.dlpi_tls_data = current->tls.image;
1908
1909 ret = (callback)(&info, sizeof (info), data);
1910
1911 if (ret != 0) break;
1912
1913 pthread_rwlock_rdlock(&lock);
1914 current = current->next;
1915 pthread_rwlock_unlock(&lock);
1916 }
1917 return ret;
1918 }
1919
1920 __attribute__((__visibility__("hidden")))
1921 void __dl_vseterr(const char *, va_list);
1922
1923 static void error(const char *fmt, ...)
1924 {
1925 va_list ap;
1926 va_start(ap, fmt);
1927 if (!runtime) {
1928 vdprintf(2, fmt, ap);
1929 dprintf(2, "\n");
1930 ldso_fail = 1;
1931 va_end(ap);
1932 return;
1933 }
1934 __dl_vseterr(fmt, ap);
1935 va_end(ap);
1936 }
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