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rewrite core of the glob implementation for correctness & optimization
[musl.git] / ldso / dynlink.c
blob42b078cf33b2f492f4621e702f0d2babe5614a3f
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 #include "malloc_impl.h"
24
25 static void error(const char *, ...);
26
27 #define MAXP2(a,b) (-(-(a)&-(b)))
28 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
29
30 struct debug {
31 int ver;
32 void *head;
33 void (*bp)(void);
34 int state;
35 void *base;
36 };
37
38 struct td_index {
39 size_t args[2];
40 struct td_index *next;
41 };
42
43 struct dso {
44 #if DL_FDPIC
45 struct fdpic_loadmap *loadmap;
46 #else
47 unsigned char *base;
48 #endif
49 char *name;
50 size_t *dynv;
51 struct dso *next, *prev;
52
53 Phdr *phdr;
54 int phnum;
55 size_t phentsize;
56 Sym *syms;
57 Elf_Symndx *hashtab;
58 uint32_t *ghashtab;
59 int16_t *versym;
60 char *strings;
61 struct dso *syms_next, *lazy_next;
62 size_t *lazy, lazy_cnt;
63 unsigned char *map;
64 size_t map_len;
65 dev_t dev;
66 ino_t ino;
67 char relocated;
68 char constructed;
69 char kernel_mapped;
70 struct dso **deps, *needed_by;
71 char *rpath_orig, *rpath;
72 struct tls_module tls;
73 size_t tls_id;
74 size_t relro_start, relro_end;
75 uintptr_t *new_dtv;
76 unsigned char *new_tls;
77 volatile int new_dtv_idx, new_tls_idx;
78 struct td_index *td_index;
79 struct dso *fini_next;
80 char *shortname;
81 #if DL_FDPIC
82 unsigned char *base;
83 #else
84 struct fdpic_loadmap *loadmap;
85 #endif
86 struct funcdesc {
87 void *addr;
88 size_t *got;
89 } *funcdescs;
90 size_t *got;
91 char buf[];
92 };
93
94 struct symdef {
95 Sym *sym;
96 struct dso *dso;
97 };
98
99 static struct builtin_tls {
100 char c;
101 struct pthread pt;
102 void *space[16];
103 } builtin_tls[1];
104 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
105
106 #define ADDEND_LIMIT 4096
107 static size_t *saved_addends, *apply_addends_to;
108
109 static struct dso ldso;
110 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
111 static char *env_path, *sys_path;
112 static unsigned long long gencnt;
113 static int runtime;
114 static int ldd_mode;
115 static int ldso_fail;
116 static int noload;
117 static jmp_buf *rtld_fail;
118 static pthread_rwlock_t lock;
119 static struct debug debug;
120 static struct tls_module *tls_tail;
121 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
122 static size_t static_tls_cnt;
123 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
124 static struct fdpic_loadmap *app_loadmap;
125 static struct fdpic_dummy_loadmap app_dummy_loadmap;
126 static struct dso *const nodeps_dummy;
127
128 struct debug *_dl_debug_addr = &debug;
129
130 extern hidden int __malloc_replaced;
131
132 hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
133
134 extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
135
136 weak_alias(__init_array_start, __init_array_end);
137 weak_alias(__fini_array_start, __fini_array_end);
138
139 static int dl_strcmp(const char *l, const char *r)
140 {
141 for (; *l==*r && *l; l++, r++);
142 return *(unsigned char *)l - *(unsigned char *)r;
143 }
144 #define strcmp(l,r) dl_strcmp(l,r)
145
146 /* Compute load address for a virtual address in a given dso. */
147 #if DL_FDPIC
148 static void *laddr(const struct dso *p, size_t v)
149 {
150 size_t j=0;
151 if (!p->loadmap) return p->base + v;
152 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
153 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
154 }
155 static void *laddr_pg(const struct dso *p, size_t v)
156 {
157 size_t j=0;
158 size_t pgsz = PAGE_SIZE;
159 if (!p->loadmap) return p->base + v;
160 for (j=0; ; j++) {
161 size_t a = p->loadmap->segs[j].p_vaddr;
162 size_t b = a + p->loadmap->segs[j].p_memsz;
163 a &= -pgsz;
164 b += pgsz-1;
165 b &= -pgsz;
166 if (v-a<b-a) break;
167 }
168 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
169 }
170 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
171 laddr(p, v), (p)->got })
172 #else
173 #define laddr(p, v) (void *)((p)->base + (v))
174 #define laddr_pg(p, v) laddr(p, v)
175 #define fpaddr(p, v) ((void (*)())laddr(p, v))
176 #endif
177
178 static void decode_vec(size_t *v, size_t *a, size_t cnt)
179 {
180 size_t i;
181 for (i=0; i<cnt; i++) a[i] = 0;
182 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
183 a[0] |= 1UL<<v[0];
184 a[v[0]] = v[1];
185 }
186 }
187
188 static int search_vec(size_t *v, size_t *r, size_t key)
189 {
190 for (; v[0]!=key; v+=2)
191 if (!v[0]) return 0;
192 *r = v[1];
193 return 1;
194 }
195
196 static uint32_t sysv_hash(const char *s0)
197 {
198 const unsigned char *s = (void *)s0;
199 uint_fast32_t h = 0;
200 while (*s) {
201 h = 16*h + *s++;
202 h ^= h>>24 & 0xf0;
203 }
204 return h & 0xfffffff;
205 }
206
207 static uint32_t gnu_hash(const char *s0)
208 {
209 const unsigned char *s = (void *)s0;
210 uint_fast32_t h = 5381;
211 for (; *s; s++)
212 h += h*32 + *s;
213 return h;
214 }
215
216 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
217 {
218 size_t i;
219 Sym *syms = dso->syms;
220 Elf_Symndx *hashtab = dso->hashtab;
221 char *strings = dso->strings;
222 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
223 if ((!dso->versym || dso->versym[i] >= 0)
224 && (!strcmp(s, strings+syms[i].st_name)))
225 return syms+i;
226 }
227 return 0;
228 }
229
230 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
231 {
232 uint32_t nbuckets = hashtab[0];
233 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
234 uint32_t i = buckets[h1 % nbuckets];
235
236 if (!i) return 0;
237
238 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
239
240 for (h1 |= 1; ; i++) {
241 uint32_t h2 = *hashval++;
242 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
243 && !strcmp(s, dso->strings + dso->syms[i].st_name))
244 return dso->syms+i;
245 if (h2 & 1) break;
246 }
247
248 return 0;
249 }
250
251 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
252 {
253 const size_t *bloomwords = (const void *)(hashtab+4);
254 size_t f = bloomwords[fofs & (hashtab[2]-1)];
255 if (!(f & fmask)) return 0;
256
257 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
258 if (!(f & 1)) return 0;
259
260 return gnu_lookup(h1, hashtab, dso, s);
261 }
262
263 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
264 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
265
266 #ifndef ARCH_SYM_REJECT_UND
267 #define ARCH_SYM_REJECT_UND(s) 0
268 #endif
269
270 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
271 {
272 uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
273 size_t ghm = 1ul << gh % (8*sizeof(size_t));
274 struct symdef def = {0};
275 for (; dso; dso=dso->syms_next) {
276 Sym *sym;
277 if ((ght = dso->ghashtab)) {
278 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
279 } else {
280 if (!h) h = sysv_hash(s);
281 sym = sysv_lookup(s, h, dso);
282 }
283 if (!sym) continue;
284 if (!sym->st_shndx)
285 if (need_def || (sym->st_info&0xf) == STT_TLS
286 || ARCH_SYM_REJECT_UND(sym))
287 continue;
288 if (!sym->st_value)
289 if ((sym->st_info&0xf) != STT_TLS)
290 continue;
291 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
292 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
293 def.sym = sym;
294 def.dso = dso;
295 break;
296 }
297 return def;
298 }
299
300 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
301 {
302 unsigned char *base = dso->base;
303 Sym *syms = dso->syms;
304 char *strings = dso->strings;
305 Sym *sym;
306 const char *name;
307 void *ctx;
308 int type;
309 int sym_index;
310 struct symdef def;
311 size_t *reloc_addr;
312 size_t sym_val;
313 size_t tls_val;
314 size_t addend;
315 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
316
317 if (dso == &ldso) {
318 /* Only ldso's REL table needs addend saving/reuse. */
319 if (rel == apply_addends_to)
320 reuse_addends = 1;
321 skip_relative = 1;
322 }
323
324 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
325 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
326 type = R_TYPE(rel[1]);
327 if (type == REL_NONE) continue;
328 reloc_addr = laddr(dso, rel[0]);
329
330 if (stride > 2) {
331 addend = rel[2];
332 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
333 addend = 0;
334 } else if (reuse_addends) {
335 /* Save original addend in stage 2 where the dso
336 * chain consists of just ldso; otherwise read back
337 * saved addend since the inline one was clobbered. */
338 if (head==&ldso)
339 saved_addends[save_slot] = *reloc_addr;
340 addend = saved_addends[save_slot++];
341 } else {
342 addend = *reloc_addr;
343 }
344
345 sym_index = R_SYM(rel[1]);
346 if (sym_index) {
347 sym = syms + sym_index;
348 name = strings + sym->st_name;
349 ctx = type==REL_COPY ? head->syms_next : head;
350 def = (sym->st_info&0xf) == STT_SECTION
351 ? (struct symdef){ .dso = dso, .sym = sym }
352 : find_sym(ctx, name, type==REL_PLT);
353 if (!def.sym && (sym->st_shndx != SHN_UNDEF
354 || sym->st_info>>4 != STB_WEAK)) {
355 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
356 dso->lazy[3*dso->lazy_cnt+0] = rel[0];
357 dso->lazy[3*dso->lazy_cnt+1] = rel[1];
358 dso->lazy[3*dso->lazy_cnt+2] = addend;
359 dso->lazy_cnt++;
360 continue;
361 }
362 error("Error relocating %s: %s: symbol not found",
363 dso->name, name);
364 if (runtime) longjmp(*rtld_fail, 1);
365 continue;
366 }
367 } else {
368 sym = 0;
369 def.sym = 0;
370 def.dso = dso;
371 }
372
373 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
374 tls_val = def.sym ? def.sym->st_value : 0;
375
376 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
377 && runtime && def.dso->tls_id > static_tls_cnt) {
378 error("Error relocating %s: %s: initial-exec TLS "
379 "resolves to dynamic definition in %s",
380 dso->name, name, def.dso->name);
381 longjmp(*rtld_fail, 1);
382 }
383
384 switch(type) {
385 case REL_NONE:
386 break;
387 case REL_OFFSET:
388 addend -= (size_t)reloc_addr;
389 case REL_SYMBOLIC:
390 case REL_GOT:
391 case REL_PLT:
392 *reloc_addr = sym_val + addend;
393 break;
394 case REL_RELATIVE:
395 *reloc_addr = (size_t)base + addend;
396 break;
397 case REL_SYM_OR_REL:
398 if (sym) *reloc_addr = sym_val + addend;
399 else *reloc_addr = (size_t)base + addend;
400 break;
401 case REL_COPY:
402 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
403 break;
404 case REL_OFFSET32:
405 *(uint32_t *)reloc_addr = sym_val + addend
406 - (size_t)reloc_addr;
407 break;
408 case REL_FUNCDESC:
409 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
410 + (def.sym - def.dso->syms)) : 0;
411 break;
412 case REL_FUNCDESC_VAL:
413 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
414 else *reloc_addr = sym_val;
415 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
416 break;
417 case REL_DTPMOD:
418 *reloc_addr = def.dso->tls_id;
419 break;
420 case REL_DTPOFF:
421 *reloc_addr = tls_val + addend - DTP_OFFSET;
422 break;
423 #ifdef TLS_ABOVE_TP
424 case REL_TPOFF:
425 *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
426 break;
427 #else
428 case REL_TPOFF:
429 *reloc_addr = tls_val - def.dso->tls.offset + addend;
430 break;
431 case REL_TPOFF_NEG:
432 *reloc_addr = def.dso->tls.offset - tls_val + addend;
433 break;
434 #endif
435 case REL_TLSDESC:
436 if (stride<3) addend = reloc_addr[1];
437 if (runtime && def.dso->tls_id > static_tls_cnt) {
438 struct td_index *new = malloc(sizeof *new);
439 if (!new) {
440 error(
441 "Error relocating %s: cannot allocate TLSDESC for %s",
442 dso->name, sym ? name : "(local)" );
443 longjmp(*rtld_fail, 1);
444 }
445 new->next = dso->td_index;
446 dso->td_index = new;
447 new->args[0] = def.dso->tls_id;
448 new->args[1] = tls_val + addend - DTP_OFFSET;
449 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
450 reloc_addr[1] = (size_t)new;
451 } else {
452 reloc_addr[0] = (size_t)__tlsdesc_static;
453 #ifdef TLS_ABOVE_TP
454 reloc_addr[1] = tls_val + def.dso->tls.offset
455 + TPOFF_K + addend;
456 #else
457 reloc_addr[1] = tls_val - def.dso->tls.offset
458 + addend;
459 #endif
460 }
461 #ifdef TLSDESC_BACKWARDS
462 /* Some archs (32-bit ARM at least) invert the order of
463 * the descriptor members. Fix them up here. */
464 size_t tmp = reloc_addr[0];
465 reloc_addr[0] = reloc_addr[1];
466 reloc_addr[1] = tmp;
467 #endif
468 break;
469 default:
470 error("Error relocating %s: unsupported relocation type %d",
471 dso->name, type);
472 if (runtime) longjmp(*rtld_fail, 1);
473 continue;
474 }
475 }
476 }
477
478 static void redo_lazy_relocs()
479 {
480 struct dso *p = lazy_head, *next;
481 lazy_head = 0;
482 for (; p; p=next) {
483 next = p->lazy_next;
484 size_t size = p->lazy_cnt*3*sizeof(size_t);
485 p->lazy_cnt = 0;
486 do_relocs(p, p->lazy, size, 3);
487 if (p->lazy_cnt) {
488 p->lazy_next = lazy_head;
489 lazy_head = p;
490 } else {
491 free(p->lazy);
492 p->lazy = 0;
493 p->lazy_next = 0;
494 }
495 }
496 }
497
498 /* A huge hack: to make up for the wastefulness of shared libraries
499 * needing at least a page of dirty memory even if they have no global
500 * data, we reclaim the gaps at the beginning and end of writable maps
501 * and "donate" them to the heap. */
502
503 static void reclaim(struct dso *dso, size_t start, size_t end)
504 {
505 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
506 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
507 if (start >= end) return;
508 char *base = laddr_pg(dso, start);
509 __malloc_donate(base, base+(end-start));
510 }
511
512 static void reclaim_gaps(struct dso *dso)
513 {
514 Phdr *ph = dso->phdr;
515 size_t phcnt = dso->phnum;
516
517 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
518 if (ph->p_type!=PT_LOAD) continue;
519 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
520 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
521 reclaim(dso, ph->p_vaddr+ph->p_memsz,
522 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
523 }
524 }
525
526 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
527 {
528 static int no_map_fixed;
529 char *q;
530 if (!no_map_fixed) {
531 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
532 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
533 return q;
534 no_map_fixed = 1;
535 }
536 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
537 if (flags & MAP_ANONYMOUS) {
538 memset(p, 0, n);
539 return p;
540 }
541 ssize_t r;
542 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
543 for (q=p; n; q+=r, off+=r, n-=r) {
544 r = read(fd, q, n);
545 if (r < 0 && errno != EINTR) return MAP_FAILED;
546 if (!r) {
547 memset(q, 0, n);
548 break;
549 }
550 }
551 return p;
552 }
553
554 static void unmap_library(struct dso *dso)
555 {
556 if (dso->loadmap) {
557 size_t i;
558 for (i=0; i<dso->loadmap->nsegs; i++) {
559 if (!dso->loadmap->segs[i].p_memsz)
560 continue;
561 munmap((void *)dso->loadmap->segs[i].addr,
562 dso->loadmap->segs[i].p_memsz);
563 }
564 free(dso->loadmap);
565 } else if (dso->map && dso->map_len) {
566 munmap(dso->map, dso->map_len);
567 }
568 }
569
570 static void *map_library(int fd, struct dso *dso)
571 {
572 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
573 void *allocated_buf=0;
574 size_t phsize;
575 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
576 size_t this_min, this_max;
577 size_t nsegs = 0;
578 off_t off_start;
579 Ehdr *eh;
580 Phdr *ph, *ph0;
581 unsigned prot;
582 unsigned char *map=MAP_FAILED, *base;
583 size_t dyn=0;
584 size_t tls_image=0;
585 size_t i;
586
587 ssize_t l = read(fd, buf, sizeof buf);
588 eh = buf;
589 if (l<0) return 0;
590 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
591 goto noexec;
592 phsize = eh->e_phentsize * eh->e_phnum;
593 if (phsize > sizeof buf - sizeof *eh) {
594 allocated_buf = malloc(phsize);
595 if (!allocated_buf) return 0;
596 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
597 if (l < 0) goto error;
598 if (l != phsize) goto noexec;
599 ph = ph0 = allocated_buf;
600 } else if (eh->e_phoff + phsize > l) {
601 l = pread(fd, buf+1, phsize, eh->e_phoff);
602 if (l < 0) goto error;
603 if (l != phsize) goto noexec;
604 ph = ph0 = (void *)(buf + 1);
605 } else {
606 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
607 }
608 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
609 if (ph->p_type == PT_DYNAMIC) {
610 dyn = ph->p_vaddr;
611 } else if (ph->p_type == PT_TLS) {
612 tls_image = ph->p_vaddr;
613 dso->tls.align = ph->p_align;
614 dso->tls.len = ph->p_filesz;
615 dso->tls.size = ph->p_memsz;
616 } else if (ph->p_type == PT_GNU_RELRO) {
617 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
618 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
619 } else if (ph->p_type == PT_GNU_STACK) {
620 if (!runtime && ph->p_memsz > __default_stacksize) {
621 __default_stacksize =
622 ph->p_memsz < DEFAULT_STACK_MAX ?
623 ph->p_memsz : DEFAULT_STACK_MAX;
624 }
625 }
626 if (ph->p_type != PT_LOAD) continue;
627 nsegs++;
628 if (ph->p_vaddr < addr_min) {
629 addr_min = ph->p_vaddr;
630 off_start = ph->p_offset;
631 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
632 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
633 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
634 }
635 if (ph->p_vaddr+ph->p_memsz > addr_max) {
636 addr_max = ph->p_vaddr+ph->p_memsz;
637 }
638 }
639 if (!dyn) goto noexec;
640 if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
641 dso->loadmap = calloc(1, sizeof *dso->loadmap
642 + nsegs * sizeof *dso->loadmap->segs);
643 if (!dso->loadmap) goto error;
644 dso->loadmap->nsegs = nsegs;
645 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
646 if (ph->p_type != PT_LOAD) continue;
647 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
648 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
649 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
650 map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
651 prot, MAP_PRIVATE,
652 fd, ph->p_offset & -PAGE_SIZE);
653 if (map == MAP_FAILED) {
654 unmap_library(dso);
655 goto error;
656 }
657 dso->loadmap->segs[i].addr = (size_t)map +
658 (ph->p_vaddr & PAGE_SIZE-1);
659 dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
660 dso->loadmap->segs[i].p_memsz = ph->p_memsz;
661 i++;
662 if (prot & PROT_WRITE) {
663 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
664 + ph->p_filesz;
665 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
666 size_t pgend = brk + ph->p_memsz - ph->p_filesz
667 + PAGE_SIZE-1 & -PAGE_SIZE;
668 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
669 pgend-pgbrk, prot,
670 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
671 -1, off_start) == MAP_FAILED)
672 goto error;
673 memset(map + brk, 0, pgbrk-brk);
674 }
675 }
676 map = (void *)dso->loadmap->segs[0].addr;
677 map_len = 0;
678 goto done_mapping;
679 }
680 addr_max += PAGE_SIZE-1;
681 addr_max &= -PAGE_SIZE;
682 addr_min &= -PAGE_SIZE;
683 off_start &= -PAGE_SIZE;
684 map_len = addr_max - addr_min + off_start;
685 /* The first time, we map too much, possibly even more than
686 * the length of the file. This is okay because we will not
687 * use the invalid part; we just need to reserve the right
688 * amount of virtual address space to map over later. */
689 map = DL_NOMMU_SUPPORT
690 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
691 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
692 : mmap((void *)addr_min, map_len, prot,
693 MAP_PRIVATE, fd, off_start);
694 if (map==MAP_FAILED) goto error;
695 dso->map = map;
696 dso->map_len = map_len;
697 /* If the loaded file is not relocatable and the requested address is
698 * not available, then the load operation must fail. */
699 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
700 errno = EBUSY;
701 goto error;
702 }
703 base = map - addr_min;
704 dso->phdr = 0;
705 dso->phnum = 0;
706 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
707 if (ph->p_type != PT_LOAD) continue;
708 /* Check if the programs headers are in this load segment, and
709 * if so, record the address for use by dl_iterate_phdr. */
710 if (!dso->phdr && eh->e_phoff >= ph->p_offset
711 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
712 dso->phdr = (void *)(base + ph->p_vaddr
713 + (eh->e_phoff-ph->p_offset));
714 dso->phnum = eh->e_phnum;
715 dso->phentsize = eh->e_phentsize;
716 }
717 this_min = ph->p_vaddr & -PAGE_SIZE;
718 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
719 off_start = ph->p_offset & -PAGE_SIZE;
720 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
721 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
722 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
723 /* Reuse the existing mapping for the lowest-address LOAD */
724 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
725 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
726 goto error;
727 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
728 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
729 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
730 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
731 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)
732 goto error;
733 }
734 }
735 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
736 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
737 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
738 && errno != ENOSYS)
739 goto error;
740 break;
741 }
742 done_mapping:
743 dso->base = base;
744 dso->dynv = laddr(dso, dyn);
745 if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
746 free(allocated_buf);
747 return map;
748 noexec:
749 errno = ENOEXEC;
750 error:
751 if (map!=MAP_FAILED) unmap_library(dso);
752 free(allocated_buf);
753 return 0;
754 }
755
756 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
757 {
758 size_t l;
759 int fd;
760 for (;;) {
761 s += strspn(s, ":\n");
762 l = strcspn(s, ":\n");
763 if (l-1 >= INT_MAX) return -1;
764 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
765 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
766 switch (errno) {
767 case ENOENT:
768 case ENOTDIR:
769 case EACCES:
770 case ENAMETOOLONG:
771 break;
772 default:
773 /* Any negative value but -1 will inhibit
774 * futher path search. */
775 return -2;
776 }
777 }
778 s += l;
779 }
780 }
781
782 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
783 {
784 size_t n, l;
785 const char *s, *t, *origin;
786 char *d;
787 if (p->rpath || !p->rpath_orig) return 0;
788 if (!strchr(p->rpath_orig, '$')) {
789 p->rpath = p->rpath_orig;
790 return 0;
791 }
792 n = 0;
793 s = p->rpath_orig;
794 while ((t=strchr(s, '$'))) {
795 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
796 return 0;
797 s = t+1;
798 n++;
799 }
800 if (n > SSIZE_MAX/PATH_MAX) return 0;
801
802 if (p->kernel_mapped) {
803 /* $ORIGIN searches cannot be performed for the main program
804 * when it is suid/sgid/AT_SECURE. This is because the
805 * pathname is under the control of the caller of execve.
806 * For libraries, however, $ORIGIN can be processed safely
807 * since the library's pathname came from a trusted source
808 * (either system paths or a call to dlopen). */
809 if (libc.secure)
810 return 0;
811 l = readlink("/proc/self/exe", buf, buf_size);
812 if (l == -1) switch (errno) {
813 case ENOENT:
814 case ENOTDIR:
815 case EACCES:
816 break;
817 default:
818 return -1;
819 }
820 if (l >= buf_size)
821 return 0;
822 buf[l] = 0;
823 origin = buf;
824 } else {
825 origin = p->name;
826 }
827 t = strrchr(origin, '/');
828 if (t) {
829 l = t-origin;
830 } else {
831 /* Normally p->name will always be an absolute or relative
832 * pathname containing at least one '/' character, but in the
833 * case where ldso was invoked as a command to execute a
834 * program in the working directory, app.name may not. Fix. */
835 origin = ".";
836 l = 1;
837 }
838 /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
839 if (libc.secure && *origin != '/')
840 return 0;
841 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
842 if (!p->rpath) return -1;
843
844 d = p->rpath;
845 s = p->rpath_orig;
846 while ((t=strchr(s, '$'))) {
847 memcpy(d, s, t-s);
848 d += t-s;
849 memcpy(d, origin, l);
850 d += l;
851 /* It was determined previously that the '$' is followed
852 * either by "ORIGIN" or "{ORIGIN}". */
853 s = t + 7 + 2*(t[1]=='{');
854 }
855 strcpy(d, s);
856 return 0;
857 }
858
859 static void decode_dyn(struct dso *p)
860 {
861 size_t dyn[DYN_CNT];
862 decode_vec(p->dynv, dyn, DYN_CNT);
863 p->syms = laddr(p, dyn[DT_SYMTAB]);
864 p->strings = laddr(p, dyn[DT_STRTAB]);
865 if (dyn[0]&(1<<DT_HASH))
866 p->hashtab = laddr(p, dyn[DT_HASH]);
867 if (dyn[0]&(1<<DT_RPATH))
868 p->rpath_orig = p->strings + dyn[DT_RPATH];
869 if (dyn[0]&(1<<DT_RUNPATH))
870 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
871 if (dyn[0]&(1<<DT_PLTGOT))
872 p->got = laddr(p, dyn[DT_PLTGOT]);
873 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
874 p->ghashtab = laddr(p, *dyn);
875 if (search_vec(p->dynv, dyn, DT_VERSYM))
876 p->versym = laddr(p, *dyn);
877 }
878
879 static size_t count_syms(struct dso *p)
880 {
881 if (p->hashtab) return p->hashtab[1];
882
883 size_t nsym, i;
884 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
885 uint32_t *hashval;
886 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
887 if (buckets[i] > nsym)
888 nsym = buckets[i];
889 }
890 if (nsym) {
891 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
892 do nsym++;
893 while (!(*hashval++ & 1));
894 }
895 return nsym;
896 }
897
898 static void *dl_mmap(size_t n)
899 {
900 void *p;
901 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
902 #ifdef SYS_mmap2
903 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
904 #else
905 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
906 #endif
907 return p == MAP_FAILED ? 0 : p;
908 }
909
910 static void makefuncdescs(struct dso *p)
911 {
912 static int self_done;
913 size_t nsym = count_syms(p);
914 size_t i, size = nsym * sizeof(*p->funcdescs);
915
916 if (!self_done) {
917 p->funcdescs = dl_mmap(size);
918 self_done = 1;
919 } else {
920 p->funcdescs = malloc(size);
921 }
922 if (!p->funcdescs) {
923 if (!runtime) a_crash();
924 error("Error allocating function descriptors for %s", p->name);
925 longjmp(*rtld_fail, 1);
926 }
927 for (i=0; i<nsym; i++) {
928 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
929 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
930 p->funcdescs[i].got = p->got;
931 } else {
932 p->funcdescs[i].addr = 0;
933 p->funcdescs[i].got = 0;
934 }
935 }
936 }
937
938 static struct dso *load_library(const char *name, struct dso *needed_by)
939 {
940 char buf[2*NAME_MAX+2];
941 const char *pathname;
942 unsigned char *map;
943 struct dso *p, temp_dso = {0};
944 int fd;
945 struct stat st;
946 size_t alloc_size;
947 int n_th = 0;
948 int is_self = 0;
949
950 if (!*name) {
951 errno = EINVAL;
952 return 0;
953 }
954
955 /* Catch and block attempts to reload the implementation itself */
956 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
957 static const char reserved[] =
958 "c.pthread.rt.m.dl.util.xnet.";
959 const char *rp, *next;
960 for (rp=reserved; *rp; rp=next) {
961 next = strchr(rp, '.') + 1;
962 if (strncmp(name+3, rp, next-rp) == 0)
963 break;
964 }
965 if (*rp) {
966 if (ldd_mode) {
967 /* Track which names have been resolved
968 * and only report each one once. */
969 static unsigned reported;
970 unsigned mask = 1U<<(rp-reserved);
971 if (!(reported & mask)) {
972 reported |= mask;
973 dprintf(1, "\t%s => %s (%p)\n",
974 name, ldso.name,
975 ldso.base);
976 }
977 }
978 is_self = 1;
979 }
980 }
981 if (!strcmp(name, ldso.name)) is_self = 1;
982 if (is_self) {
983 if (!ldso.prev) {
984 tail->next = &ldso;
985 ldso.prev = tail;
986 tail = &ldso;
987 }
988 return &ldso;
989 }
990 if (strchr(name, '/')) {
991 pathname = name;
992 fd = open(name, O_RDONLY|O_CLOEXEC);
993 } else {
994 /* Search for the name to see if it's already loaded */
995 for (p=head->next; p; p=p->next) {
996 if (p->shortname && !strcmp(p->shortname, name)) {
997 return p;
998 }
999 }
1000 if (strlen(name) > NAME_MAX) return 0;
1001 fd = -1;
1002 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
1003 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
1004 if (fixup_rpath(p, buf, sizeof buf) < 0)
1005 fd = -2; /* Inhibit further search. */
1006 if (p->rpath)
1007 fd = path_open(name, p->rpath, buf, sizeof buf);
1008 }
1009 if (fd == -1) {
1010 if (!sys_path) {
1011 char *prefix = 0;
1012 size_t prefix_len;
1013 if (ldso.name[0]=='/') {
1014 char *s, *t, *z;
1015 for (s=t=z=ldso.name; *s; s++)
1016 if (*s=='/') z=t, t=s;
1017 prefix_len = z-ldso.name;
1018 if (prefix_len < PATH_MAX)
1019 prefix = ldso.name;
1020 }
1021 if (!prefix) {
1022 prefix = "";
1023 prefix_len = 0;
1024 }
1025 char etc_ldso_path[prefix_len + 1
1026 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1027 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1028 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1029 (int)prefix_len, prefix);
1030 FILE *f = fopen(etc_ldso_path, "rbe");
1031 if (f) {
1032 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1033 free(sys_path);
1034 sys_path = "";
1035 }
1036 fclose(f);
1037 } else if (errno != ENOENT) {
1038 sys_path = "";
1039 }
1040 }
1041 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1042 fd = path_open(name, sys_path, buf, sizeof buf);
1043 }
1044 pathname = buf;
1045 }
1046 if (fd < 0) return 0;
1047 if (fstat(fd, &st) < 0) {
1048 close(fd);
1049 return 0;
1050 }
1051 for (p=head->next; p; p=p->next) {
1052 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1053 /* If this library was previously loaded with a
1054 * pathname but a search found the same inode,
1055 * setup its shortname so it can be found by name. */
1056 if (!p->shortname && pathname != name)
1057 p->shortname = strrchr(p->name, '/')+1;
1058 close(fd);
1059 return p;
1060 }
1061 }
1062 map = noload ? 0 : map_library(fd, &temp_dso);
1063 close(fd);
1064 if (!map) return 0;
1065
1066 /* Avoid the danger of getting two versions of libc mapped into the
1067 * same process when an absolute pathname was used. The symbols
1068 * checked are chosen to catch both musl and glibc, and to avoid
1069 * false positives from interposition-hack libraries. */
1070 decode_dyn(&temp_dso);
1071 if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1072 find_sym(&temp_dso, "stdin", 1).sym) {
1073 unmap_library(&temp_dso);
1074 return load_library("libc.so", needed_by);
1075 }
1076 /* Past this point, if we haven't reached runtime yet, ldso has
1077 * committed either to use the mapped library or to abort execution.
1078 * Unmapping is not possible, so we can safely reclaim gaps. */
1079 if (!runtime) reclaim_gaps(&temp_dso);
1080
1081 /* Allocate storage for the new DSO. When there is TLS, this
1082 * storage must include a reservation for all pre-existing
1083 * threads to obtain copies of both the new TLS, and an
1084 * extended DTV capable of storing an additional slot for
1085 * the newly-loaded DSO. */
1086 alloc_size = sizeof *p + strlen(pathname) + 1;
1087 if (runtime && temp_dso.tls.image) {
1088 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1089 + sizeof(void *) * (tls_cnt+3);
1090 n_th = libc.threads_minus_1 + 1;
1091 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1092 else alloc_size += n_th * per_th;
1093 }
1094 p = calloc(1, alloc_size);
1095 if (!p) {
1096 unmap_library(&temp_dso);
1097 return 0;
1098 }
1099 memcpy(p, &temp_dso, sizeof temp_dso);
1100 p->dev = st.st_dev;
1101 p->ino = st.st_ino;
1102 p->needed_by = needed_by;
1103 p->name = p->buf;
1104 strcpy(p->name, pathname);
1105 /* Add a shortname only if name arg was not an explicit pathname. */
1106 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1107 if (p->tls.image) {
1108 p->tls_id = ++tls_cnt;
1109 tls_align = MAXP2(tls_align, p->tls.align);
1110 #ifdef TLS_ABOVE_TP
1111 p->tls.offset = tls_offset + ( (tls_align-1) &
1112 -(tls_offset + (uintptr_t)p->tls.image) );
1113 tls_offset += p->tls.size;
1114 #else
1115 tls_offset += p->tls.size + p->tls.align - 1;
1116 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1117 & (p->tls.align-1);
1118 p->tls.offset = tls_offset;
1119 #endif
1120 p->new_dtv = (void *)(-sizeof(size_t) &
1121 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1122 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1123 if (tls_tail) tls_tail->next = &p->tls;
1124 else libc.tls_head = &p->tls;
1125 tls_tail = &p->tls;
1126 }
1127
1128 tail->next = p;
1129 p->prev = tail;
1130 tail = p;
1131
1132 if (DL_FDPIC) makefuncdescs(p);
1133
1134 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1135
1136 return p;
1137 }
1138
1139 static void load_deps(struct dso *p)
1140 {
1141 size_t i, ndeps=0;
1142 struct dso ***deps = &p->deps, **tmp, *dep;
1143 for (; p; p=p->next) {
1144 for (i=0; p->dynv[i]; i+=2) {
1145 if (p->dynv[i] != DT_NEEDED) continue;
1146 dep = load_library(p->strings + p->dynv[i+1], p);
1147 if (!dep) {
1148 error("Error loading shared library %s: %m (needed by %s)",
1149 p->strings + p->dynv[i+1], p->name);
1150 if (runtime) longjmp(*rtld_fail, 1);
1151 continue;
1152 }
1153 if (runtime) {
1154 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1155 if (!tmp) longjmp(*rtld_fail, 1);
1156 tmp[ndeps++] = dep;
1157 tmp[ndeps] = 0;
1158 *deps = tmp;
1159 }
1160 }
1161 }
1162 if (!*deps) *deps = (struct dso **)&nodeps_dummy;
1163 }
1164
1165 static void load_preload(char *s)
1166 {
1167 int tmp;
1168 char *z;
1169 for (z=s; *z; s=z) {
1170 for ( ; *s && (isspace(*s) || *s==':'); s++);
1171 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1172 tmp = *z;
1173 *z = 0;
1174 load_library(s, 0);
1175 *z = tmp;
1176 }
1177 }
1178
1179 static void add_syms(struct dso *p)
1180 {
1181 if (!p->syms_next && syms_tail != p) {
1182 syms_tail->syms_next = p;
1183 syms_tail = p;
1184 }
1185 }
1186
1187 static void revert_syms(struct dso *old_tail)
1188 {
1189 struct dso *p, *next;
1190 /* Chop off the tail of the list of dsos that participate in
1191 * the global symbol table, reverting them to RTLD_LOCAL. */
1192 for (p=old_tail; p; p=next) {
1193 next = p->syms_next;
1194 p->syms_next = 0;
1195 }
1196 syms_tail = old_tail;
1197 }
1198
1199 static void do_mips_relocs(struct dso *p, size_t *got)
1200 {
1201 size_t i, j, rel[2];
1202 unsigned char *base = p->base;
1203 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1204 if (p==&ldso) {
1205 got += i;
1206 } else {
1207 while (i--) *got++ += (size_t)base;
1208 }
1209 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1210 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1211 Sym *sym = p->syms + j;
1212 rel[0] = (unsigned char *)got - base;
1213 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1214 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1215 do_relocs(p, rel, sizeof rel, 2);
1216 }
1217 }
1218
1219 static void reloc_all(struct dso *p)
1220 {
1221 size_t dyn[DYN_CNT];
1222 for (; p; p=p->next) {
1223 if (p->relocated) continue;
1224 decode_vec(p->dynv, dyn, DYN_CNT);
1225 if (NEED_MIPS_GOT_RELOCS)
1226 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1227 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1228 2+(dyn[DT_PLTREL]==DT_RELA));
1229 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1230 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1231
1232 if (head != &ldso && p->relro_start != p->relro_end &&
1233 mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1234 && errno != ENOSYS) {
1235 error("Error relocating %s: RELRO protection failed: %m",
1236 p->name);
1237 if (runtime) longjmp(*rtld_fail, 1);
1238 }
1239
1240 p->relocated = 1;
1241 }
1242 }
1243
1244 static void kernel_mapped_dso(struct dso *p)
1245 {
1246 size_t min_addr = -1, max_addr = 0, cnt;
1247 Phdr *ph = p->phdr;
1248 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1249 if (ph->p_type == PT_DYNAMIC) {
1250 p->dynv = laddr(p, ph->p_vaddr);
1251 } else if (ph->p_type == PT_GNU_RELRO) {
1252 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1253 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1254 } else if (ph->p_type == PT_GNU_STACK) {
1255 if (!runtime && ph->p_memsz > __default_stacksize) {
1256 __default_stacksize =
1257 ph->p_memsz < DEFAULT_STACK_MAX ?
1258 ph->p_memsz : DEFAULT_STACK_MAX;
1259 }
1260 }
1261 if (ph->p_type != PT_LOAD) continue;
1262 if (ph->p_vaddr < min_addr)
1263 min_addr = ph->p_vaddr;
1264 if (ph->p_vaddr+ph->p_memsz > max_addr)
1265 max_addr = ph->p_vaddr+ph->p_memsz;
1266 }
1267 min_addr &= -PAGE_SIZE;
1268 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1269 p->map = p->base + min_addr;
1270 p->map_len = max_addr - min_addr;
1271 p->kernel_mapped = 1;
1272 }
1273
1274 void __libc_exit_fini()
1275 {
1276 struct dso *p;
1277 size_t dyn[DYN_CNT];
1278 for (p=fini_head; p; p=p->fini_next) {
1279 if (!p->constructed) continue;
1280 decode_vec(p->dynv, dyn, DYN_CNT);
1281 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1282 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1283 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1284 while (n--) ((void (*)(void))*--fn)();
1285 }
1286 #ifndef NO_LEGACY_INITFINI
1287 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1288 fpaddr(p, dyn[DT_FINI])();
1289 #endif
1290 }
1291 }
1292
1293 static void do_init_fini(struct dso *p)
1294 {
1295 size_t dyn[DYN_CNT];
1296 int need_locking = libc.threads_minus_1;
1297 /* Allow recursive calls that arise when a library calls
1298 * dlopen from one of its constructors, but block any
1299 * other threads until all ctors have finished. */
1300 if (need_locking) pthread_mutex_lock(&init_fini_lock);
1301 for (; p; p=p->prev) {
1302 if (p->constructed) continue;
1303 p->constructed = 1;
1304 decode_vec(p->dynv, dyn, DYN_CNT);
1305 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1306 p->fini_next = fini_head;
1307 fini_head = p;
1308 }
1309 #ifndef NO_LEGACY_INITFINI
1310 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1311 fpaddr(p, dyn[DT_INIT])();
1312 #endif
1313 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1314 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1315 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1316 while (n--) ((void (*)(void))*fn++)();
1317 }
1318 if (!need_locking && libc.threads_minus_1) {
1319 need_locking = 1;
1320 pthread_mutex_lock(&init_fini_lock);
1321 }
1322 }
1323 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1324 }
1325
1326 void __libc_start_init(void)
1327 {
1328 do_init_fini(tail);
1329 }
1330
1331 static void dl_debug_state(void)
1332 {
1333 }
1334
1335 weak_alias(dl_debug_state, _dl_debug_state);
1336
1337 void __init_tls(size_t *auxv)
1338 {
1339 }
1340
1341 hidden void *__tls_get_new(tls_mod_off_t *v)
1342 {
1343 pthread_t self = __pthread_self();
1344
1345 /* Block signals to make accessing new TLS async-signal-safe */
1346 sigset_t set;
1347 __block_all_sigs(&set);
1348 if (v[0] <= self->dtv[0]) {
1349 __restore_sigs(&set);
1350 return (void *)(self->dtv[v[0]] + v[1]);
1351 }
1352
1353 /* This is safe without any locks held because, if the caller
1354 * is able to request the Nth entry of the DTV, the DSO list
1355 * must be valid at least that far out and it was synchronized
1356 * at program startup or by an already-completed call to dlopen. */
1357 struct dso *p;
1358 for (p=head; p->tls_id != v[0]; p=p->next);
1359
1360 /* Get new DTV space from new DSO */
1361 uintptr_t *newdtv = p->new_dtv +
1362 (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1363 memcpy(newdtv, self->dtv, (self->dtv[0]+1) * sizeof(uintptr_t));
1364 newdtv[0] = v[0];
1365 self->dtv = self->dtv_copy = newdtv;
1366
1367 /* Get new TLS memory from all new DSOs up to the requested one */
1368 unsigned char *mem;
1369 for (p=head; ; p=p->next) {
1370 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1371 mem = p->new_tls + (p->tls.size + p->tls.align)
1372 * a_fetch_add(&p->new_tls_idx,1);
1373 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1374 & (p->tls.align-1);
1375 self->dtv[p->tls_id] = (uintptr_t)mem + DTP_OFFSET;
1376 memcpy(mem, p->tls.image, p->tls.len);
1377 if (p->tls_id == v[0]) break;
1378 }
1379 __restore_sigs(&set);
1380 return mem + v[1] + DTP_OFFSET;
1381 }
1382
1383 static void update_tls_size()
1384 {
1385 libc.tls_cnt = tls_cnt;
1386 libc.tls_align = tls_align;
1387 libc.tls_size = ALIGN(
1388 (1+tls_cnt) * sizeof(void *) +
1389 tls_offset +
1390 sizeof(struct pthread) +
1391 tls_align * 2,
1392 tls_align);
1393 }
1394
1395 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1396 * following stage 2 and stage 3 functions via primitive symbolic lookup
1397 * since it does not have access to their addresses to begin with. */
1398
1399 /* Stage 2 of the dynamic linker is called after relative relocations
1400 * have been processed. It can make function calls to static functions
1401 * and access string literals and static data, but cannot use extern
1402 * symbols. Its job is to perform symbolic relocations on the dynamic
1403 * linker itself, but some of the relocations performed may need to be
1404 * replaced later due to copy relocations in the main program. */
1405
1406 hidden void __dls2(unsigned char *base, size_t *sp)
1407 {
1408 if (DL_FDPIC) {
1409 void *p1 = (void *)sp[-2];
1410 void *p2 = (void *)sp[-1];
1411 if (!p1) {
1412 size_t *auxv, aux[AUX_CNT];
1413 for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1414 decode_vec(auxv, aux, AUX_CNT);
1415 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1416 else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1417 }
1418 app_loadmap = p2 ? p1 : 0;
1419 ldso.loadmap = p2 ? p2 : p1;
1420 ldso.base = laddr(&ldso, 0);
1421 } else {
1422 ldso.base = base;
1423 }
1424 Ehdr *ehdr = (void *)ldso.base;
1425 ldso.name = ldso.shortname = "libc.so";
1426 ldso.phnum = ehdr->e_phnum;
1427 ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1428 ldso.phentsize = ehdr->e_phentsize;
1429 kernel_mapped_dso(&ldso);
1430 decode_dyn(&ldso);
1431
1432 if (DL_FDPIC) makefuncdescs(&ldso);
1433
1434 /* Prepare storage for to save clobbered REL addends so they
1435 * can be reused in stage 3. There should be very few. If
1436 * something goes wrong and there are a huge number, abort
1437 * instead of risking stack overflow. */
1438 size_t dyn[DYN_CNT];
1439 decode_vec(ldso.dynv, dyn, DYN_CNT);
1440 size_t *rel = laddr(&ldso, dyn[DT_REL]);
1441 size_t rel_size = dyn[DT_RELSZ];
1442 size_t symbolic_rel_cnt = 0;
1443 apply_addends_to = rel;
1444 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1445 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1446 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1447 size_t addends[symbolic_rel_cnt+1];
1448 saved_addends = addends;
1449
1450 head = &ldso;
1451 reloc_all(&ldso);
1452
1453 ldso.relocated = 0;
1454
1455 /* Call dynamic linker stage-3, __dls3, looking it up
1456 * symbolically as a barrier against moving the address
1457 * load across the above relocation processing. */
1458 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1459 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1460 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1461 }
1462
1463 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1464 * fully functional. Its job is to load (if not already loaded) and
1465 * process dependencies and relocations for the main application and
1466 * transfer control to its entry point. */
1467
1468 _Noreturn void __dls3(size_t *sp)
1469 {
1470 static struct dso app, vdso;
1471 size_t aux[AUX_CNT], *auxv;
1472 size_t i;
1473 char *env_preload=0;
1474 char *replace_argv0=0;
1475 size_t vdso_base;
1476 int argc = *sp;
1477 char **argv = (void *)(sp+1);
1478 char **argv_orig = argv;
1479 char **envp = argv+argc+1;
1480
1481 /* Find aux vector just past environ[] and use it to initialize
1482 * global data that may be needed before we can make syscalls. */
1483 __environ = envp;
1484 for (i=argc+1; argv[i]; i++);
1485 libc.auxv = auxv = (void *)(argv+i+1);
1486 decode_vec(auxv, aux, AUX_CNT);
1487 __hwcap = aux[AT_HWCAP];
1488 libc.page_size = aux[AT_PAGESZ];
1489 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1490 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1491
1492 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1493 * use during dynamic linking. If possible it will also serve as the
1494 * thread pointer at runtime. */
1495 libc.tls_size = sizeof builtin_tls;
1496 libc.tls_align = tls_align;
1497 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1498 a_crash();
1499 }
1500
1501 /* Only trust user/env if kernel says we're not suid/sgid */
1502 if (!libc.secure) {
1503 env_path = getenv("LD_LIBRARY_PATH");
1504 env_preload = getenv("LD_PRELOAD");
1505 }
1506
1507 /* If the main program was already loaded by the kernel,
1508 * AT_PHDR will point to some location other than the dynamic
1509 * linker's program headers. */
1510 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1511 size_t interp_off = 0;
1512 size_t tls_image = 0;
1513 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1514 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1515 app.phnum = aux[AT_PHNUM];
1516 app.phentsize = aux[AT_PHENT];
1517 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1518 if (phdr->p_type == PT_PHDR)
1519 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1520 else if (phdr->p_type == PT_INTERP)
1521 interp_off = (size_t)phdr->p_vaddr;
1522 else if (phdr->p_type == PT_TLS) {
1523 tls_image = phdr->p_vaddr;
1524 app.tls.len = phdr->p_filesz;
1525 app.tls.size = phdr->p_memsz;
1526 app.tls.align = phdr->p_align;
1527 }
1528 }
1529 if (DL_FDPIC) app.loadmap = app_loadmap;
1530 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1531 if (interp_off) ldso.name = laddr(&app, interp_off);
1532 if ((aux[0] & (1UL<<AT_EXECFN))
1533 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1534 app.name = (char *)aux[AT_EXECFN];
1535 else
1536 app.name = argv[0];
1537 kernel_mapped_dso(&app);
1538 } else {
1539 int fd;
1540 char *ldname = argv[0];
1541 size_t l = strlen(ldname);
1542 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1543 argv++;
1544 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1545 char *opt = argv[0]+2;
1546 *argv++ = (void *)-1;
1547 if (!*opt) {
1548 break;
1549 } else if (!memcmp(opt, "list", 5)) {
1550 ldd_mode = 1;
1551 } else if (!memcmp(opt, "library-path", 12)) {
1552 if (opt[12]=='=') env_path = opt+13;
1553 else if (opt[12]) *argv = 0;
1554 else if (*argv) env_path = *argv++;
1555 } else if (!memcmp(opt, "preload", 7)) {
1556 if (opt[7]=='=') env_preload = opt+8;
1557 else if (opt[7]) *argv = 0;
1558 else if (*argv) env_preload = *argv++;
1559 } else if (!memcmp(opt, "argv0", 5)) {
1560 if (opt[5]=='=') replace_argv0 = opt+6;
1561 else if (opt[5]) *argv = 0;
1562 else if (*argv) replace_argv0 = *argv++;
1563 } else {
1564 argv[0] = 0;
1565 }
1566 }
1567 argv[-1] = (void *)(argc - (argv-argv_orig));
1568 if (!argv[0]) {
1569 dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1570 "Version %s\n"
1571 "Dynamic Program Loader\n"
1572 "Usage: %s [options] [--] pathname%s\n",
1573 __libc_version, ldname,
1574 ldd_mode ? "" : " [args]");
1575 _exit(1);
1576 }
1577 fd = open(argv[0], O_RDONLY);
1578 if (fd < 0) {
1579 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1580 _exit(1);
1581 }
1582 Ehdr *ehdr = (void *)map_library(fd, &app);
1583 if (!ehdr) {
1584 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1585 _exit(1);
1586 }
1587 close(fd);
1588 ldso.name = ldname;
1589 app.name = argv[0];
1590 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1591 /* Find the name that would have been used for the dynamic
1592 * linker had ldd not taken its place. */
1593 if (ldd_mode) {
1594 for (i=0; i<app.phnum; i++) {
1595 if (app.phdr[i].p_type == PT_INTERP)
1596 ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1597 }
1598 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1599 }
1600 }
1601 if (app.tls.size) {
1602 libc.tls_head = tls_tail = &app.tls;
1603 app.tls_id = tls_cnt = 1;
1604 #ifdef TLS_ABOVE_TP
1605 app.tls.offset = GAP_ABOVE_TP;
1606 app.tls.offset += -GAP_ABOVE_TP & (app.tls.align-1);
1607 tls_offset = app.tls.offset + app.tls.size
1608 + ( -((uintptr_t)app.tls.image + app.tls.size)
1609 & (app.tls.align-1) );
1610 #else
1611 tls_offset = app.tls.offset = app.tls.size
1612 + ( -((uintptr_t)app.tls.image + app.tls.size)
1613 & (app.tls.align-1) );
1614 #endif
1615 tls_align = MAXP2(tls_align, app.tls.align);
1616 }
1617 decode_dyn(&app);
1618 if (DL_FDPIC) {
1619 makefuncdescs(&app);
1620 if (!app.loadmap) {
1621 app.loadmap = (void *)&app_dummy_loadmap;
1622 app.loadmap->nsegs = 1;
1623 app.loadmap->segs[0].addr = (size_t)app.map;
1624 app.loadmap->segs[0].p_vaddr = (size_t)app.map
1625 - (size_t)app.base;
1626 app.loadmap->segs[0].p_memsz = app.map_len;
1627 }
1628 argv[-3] = (void *)app.loadmap;
1629 }
1630
1631 /* Initial dso chain consists only of the app. */
1632 head = tail = syms_tail = &app;
1633
1634 /* Donate unused parts of app and library mapping to malloc */
1635 reclaim_gaps(&app);
1636 reclaim_gaps(&ldso);
1637
1638 /* Load preload/needed libraries, add symbols to global namespace. */
1639 if (env_preload) load_preload(env_preload);
1640 load_deps(&app);
1641 for (struct dso *p=head; p; p=p->next)
1642 add_syms(p);
1643
1644 /* Attach to vdso, if provided by the kernel, last so that it does
1645 * not become part of the global namespace. */
1646 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1647 Ehdr *ehdr = (void *)vdso_base;
1648 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1649 vdso.phnum = ehdr->e_phnum;
1650 vdso.phentsize = ehdr->e_phentsize;
1651 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1652 if (phdr->p_type == PT_DYNAMIC)
1653 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1654 if (phdr->p_type == PT_LOAD)
1655 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1656 }
1657 vdso.name = "";
1658 vdso.shortname = "linux-gate.so.1";
1659 vdso.relocated = 1;
1660 decode_dyn(&vdso);
1661 vdso.prev = tail;
1662 tail->next = &vdso;
1663 tail = &vdso;
1664 }
1665
1666 for (i=0; app.dynv[i]; i+=2) {
1667 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1668 app.dynv[i+1] = (size_t)&debug;
1669 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1670 size_t *ptr = (size_t *) app.dynv[i+1];
1671 *ptr = (size_t)&debug;
1672 }
1673 }
1674
1675 /* The main program must be relocated LAST since it may contin
1676 * copy relocations which depend on libraries' relocations. */
1677 reloc_all(app.next);
1678 reloc_all(&app);
1679
1680 update_tls_size();
1681 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1682 void *initial_tls = calloc(libc.tls_size, 1);
1683 if (!initial_tls) {
1684 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1685 argv[0], libc.tls_size);
1686 _exit(127);
1687 }
1688 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1689 a_crash();
1690 }
1691 } else {
1692 size_t tmp_tls_size = libc.tls_size;
1693 pthread_t self = __pthread_self();
1694 /* Temporarily set the tls size to the full size of
1695 * builtin_tls so that __copy_tls will use the same layout
1696 * as it did for before. Then check, just to be safe. */
1697 libc.tls_size = sizeof builtin_tls;
1698 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1699 libc.tls_size = tmp_tls_size;
1700 }
1701 static_tls_cnt = tls_cnt;
1702
1703 if (ldso_fail) _exit(127);
1704 if (ldd_mode) _exit(0);
1705
1706 /* Determine if malloc was interposed by a replacement implementation
1707 * so that calloc and the memalign family can harden against the
1708 * possibility of incomplete replacement. */
1709 if (find_sym(head, "malloc", 1).dso != &ldso)
1710 __malloc_replaced = 1;
1711
1712 /* Switch to runtime mode: any further failures in the dynamic
1713 * linker are a reportable failure rather than a fatal startup
1714 * error. */
1715 runtime = 1;
1716
1717 debug.ver = 1;
1718 debug.bp = dl_debug_state;
1719 debug.head = head;
1720 debug.base = ldso.base;
1721 debug.state = 0;
1722 _dl_debug_state();
1723
1724 if (replace_argv0) argv[0] = replace_argv0;
1725
1726 errno = 0;
1727
1728 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1729 for(;;);
1730 }
1731
1732 static void prepare_lazy(struct dso *p)
1733 {
1734 size_t dyn[DYN_CNT], n, flags1=0;
1735 decode_vec(p->dynv, dyn, DYN_CNT);
1736 search_vec(p->dynv, &flags1, DT_FLAGS_1);
1737 if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1738 return;
1739 n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1740 if (NEED_MIPS_GOT_RELOCS) {
1741 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1742 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1743 n += i-j;
1744 }
1745 p->lazy = calloc(n, 3*sizeof(size_t));
1746 if (!p->lazy) {
1747 error("Error preparing lazy relocation for %s: %m", p->name);
1748 longjmp(*rtld_fail, 1);
1749 }
1750 p->lazy_next = lazy_head;
1751 lazy_head = p;
1752 }
1753
1754 void *dlopen(const char *file, int mode)
1755 {
1756 struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1757 struct tls_module *orig_tls_tail;
1758 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1759 size_t i;
1760 int cs;
1761 jmp_buf jb;
1762
1763 if (!file) return head;
1764
1765 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1766 pthread_rwlock_wrlock(&lock);
1767 __inhibit_ptc();
1768
1769 p = 0;
1770 orig_tls_tail = tls_tail;
1771 orig_tls_cnt = tls_cnt;
1772 orig_tls_offset = tls_offset;
1773 orig_tls_align = tls_align;
1774 orig_lazy_head = lazy_head;
1775 orig_syms_tail = syms_tail;
1776 orig_tail = tail;
1777 noload = mode & RTLD_NOLOAD;
1778
1779 rtld_fail = &jb;
1780 if (setjmp(*rtld_fail)) {
1781 /* Clean up anything new that was (partially) loaded */
1782 revert_syms(orig_syms_tail);
1783 for (p=orig_tail->next; p; p=next) {
1784 next = p->next;
1785 while (p->td_index) {
1786 void *tmp = p->td_index->next;
1787 free(p->td_index);
1788 p->td_index = tmp;
1789 }
1790 free(p->funcdescs);
1791 if (p->rpath != p->rpath_orig)
1792 free(p->rpath);
1793 if (p->deps != &nodeps_dummy)
1794 free(p->deps);
1795 unmap_library(p);
1796 free(p);
1797 }
1798 if (!orig_tls_tail) libc.tls_head = 0;
1799 tls_tail = orig_tls_tail;
1800 if (tls_tail) tls_tail->next = 0;
1801 tls_cnt = orig_tls_cnt;
1802 tls_offset = orig_tls_offset;
1803 tls_align = orig_tls_align;
1804 lazy_head = orig_lazy_head;
1805 tail = orig_tail;
1806 tail->next = 0;
1807 p = 0;
1808 goto end;
1809 } else p = load_library(file, head);
1810
1811 if (!p) {
1812 error(noload ?
1813 "Library %s is not already loaded" :
1814 "Error loading shared library %s: %m",
1815 file);
1816 goto end;
1817 }
1818
1819 /* First load handling */
1820 int first_load = !p->deps;
1821 if (first_load) {
1822 load_deps(p);
1823 if (!p->relocated && (mode & RTLD_LAZY)) {
1824 prepare_lazy(p);
1825 for (i=0; p->deps[i]; i++)
1826 if (!p->deps[i]->relocated)
1827 prepare_lazy(p->deps[i]);
1828 }
1829 }
1830 if (first_load || (mode & RTLD_GLOBAL)) {
1831 /* Make new symbols global, at least temporarily, so we can do
1832 * relocations. If not RTLD_GLOBAL, this is reverted below. */
1833 add_syms(p);
1834 for (i=0; p->deps[i]; i++)
1835 add_syms(p->deps[i]);
1836 }
1837 if (first_load) {
1838 reloc_all(p);
1839 }
1840
1841 /* If RTLD_GLOBAL was not specified, undo any new additions
1842 * to the global symbol table. This is a nop if the library was
1843 * previously loaded and already global. */
1844 if (!(mode & RTLD_GLOBAL))
1845 revert_syms(orig_syms_tail);
1846
1847 /* Processing of deferred lazy relocations must not happen until
1848 * the new libraries are committed; otherwise we could end up with
1849 * relocations resolved to symbol definitions that get removed. */
1850 redo_lazy_relocs();
1851
1852 update_tls_size();
1853 _dl_debug_state();
1854 orig_tail = tail;
1855 end:
1856 __release_ptc();
1857 if (p) gencnt++;
1858 pthread_rwlock_unlock(&lock);
1859 if (p) do_init_fini(orig_tail);
1860 pthread_setcancelstate(cs, 0);
1861 return p;
1862 }
1863
1864 hidden int __dl_invalid_handle(void *h)
1865 {
1866 struct dso *p;
1867 for (p=head; p; p=p->next) if (h==p) return 0;
1868 error("Invalid library handle %p", (void *)h);
1869 return 1;
1870 }
1871
1872 static void *addr2dso(size_t a)
1873 {
1874 struct dso *p;
1875 size_t i;
1876 if (DL_FDPIC) for (p=head; p; p=p->next) {
1877 i = count_syms(p);
1878 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1879 return p;
1880 }
1881 for (p=head; p; p=p->next) {
1882 if (DL_FDPIC && p->loadmap) {
1883 for (i=0; i<p->loadmap->nsegs; i++) {
1884 if (a-p->loadmap->segs[i].p_vaddr
1885 < p->loadmap->segs[i].p_memsz)
1886 return p;
1887 }
1888 } else {
1889 Phdr *ph = p->phdr;
1890 size_t phcnt = p->phnum;
1891 size_t entsz = p->phentsize;
1892 size_t base = (size_t)p->base;
1893 for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
1894 if (ph->p_type != PT_LOAD) continue;
1895 if (a-base-ph->p_vaddr < ph->p_memsz)
1896 return p;
1897 }
1898 if (a-(size_t)p->map < p->map_len)
1899 return 0;
1900 }
1901 }
1902 return 0;
1903 }
1904
1905 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1906 {
1907 size_t i;
1908 uint32_t h = 0, gh = 0, *ght;
1909 Sym *sym;
1910 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1911 if (p == RTLD_DEFAULT) {
1912 p = head;
1913 } else if (p == RTLD_NEXT) {
1914 p = addr2dso((size_t)ra);
1915 if (!p) p=head;
1916 p = p->next;
1917 }
1918 struct symdef def = find_sym(p, s, 0);
1919 if (!def.sym) goto failed;
1920 if ((def.sym->st_info&0xf) == STT_TLS)
1921 return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET});
1922 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1923 return def.dso->funcdescs + (def.sym - def.dso->syms);
1924 return laddr(def.dso, def.sym->st_value);
1925 }
1926 if (__dl_invalid_handle(p))
1927 return 0;
1928 if ((ght = p->ghashtab)) {
1929 gh = gnu_hash(s);
1930 sym = gnu_lookup(gh, ght, p, s);
1931 } else {
1932 h = sysv_hash(s);
1933 sym = sysv_lookup(s, h, p);
1934 }
1935 if (sym && (sym->st_info&0xf) == STT_TLS)
1936 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value-DTP_OFFSET});
1937 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1938 return p->funcdescs + (sym - p->syms);
1939 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1940 return laddr(p, sym->st_value);
1941 for (i=0; p->deps[i]; i++) {
1942 if ((ght = p->deps[i]->ghashtab)) {
1943 if (!gh) gh = gnu_hash(s);
1944 sym = gnu_lookup(gh, ght, p->deps[i], s);
1945 } else {
1946 if (!h) h = sysv_hash(s);
1947 sym = sysv_lookup(s, h, p->deps[i]);
1948 }
1949 if (sym && (sym->st_info&0xf) == STT_TLS)
1950 return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value-DTP_OFFSET});
1951 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1952 return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1953 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1954 return laddr(p->deps[i], sym->st_value);
1955 }
1956 failed:
1957 error("Symbol not found: %s", s);
1958 return 0;
1959 }
1960
1961 int dladdr(const void *addr_arg, Dl_info *info)
1962 {
1963 size_t addr = (size_t)addr_arg;
1964 struct dso *p;
1965 Sym *sym, *bestsym;
1966 uint32_t nsym;
1967 char *strings;
1968 size_t best = 0;
1969 size_t besterr = -1;
1970
1971 pthread_rwlock_rdlock(&lock);
1972 p = addr2dso(addr);
1973 pthread_rwlock_unlock(&lock);
1974
1975 if (!p) return 0;
1976
1977 sym = p->syms;
1978 strings = p->strings;
1979 nsym = count_syms(p);
1980
1981 if (DL_FDPIC) {
1982 size_t idx = (addr-(size_t)p->funcdescs)
1983 / sizeof(*p->funcdescs);
1984 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1985 best = (size_t)(p->funcdescs + idx);
1986 bestsym = sym + idx;
1987 besterr = 0;
1988 }
1989 }
1990
1991 if (!best) for (; nsym; nsym--, sym++) {
1992 if (sym->st_value
1993 && (1<<(sym->st_info&0xf) & OK_TYPES)
1994 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1995 size_t symaddr = (size_t)laddr(p, sym->st_value);
1996 if (symaddr > addr || symaddr <= best)
1997 continue;
1998 best = symaddr;
1999 bestsym = sym;
2000 besterr = addr - symaddr;
2001 if (addr == symaddr)
2002 break;
2003 }
2004 }
2005
2006 if (bestsym && besterr > bestsym->st_size-1) {
2007 best = 0;
2008 bestsym = 0;
2009 }
2010
2011 info->dli_fname = p->name;
2012 info->dli_fbase = p->map;
2013
2014 if (!best) {
2015 info->dli_sname = 0;
2016 info->dli_saddr = 0;
2017 return 1;
2018 }
2019
2020 if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2021 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2022 info->dli_sname = strings + bestsym->st_name;
2023 info->dli_saddr = (void *)best;
2024
2025 return 1;
2026 }
2027
2028 hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2029 {
2030 void *res;
2031 pthread_rwlock_rdlock(&lock);
2032 res = do_dlsym(p, s, ra);
2033 pthread_rwlock_unlock(&lock);
2034 return res;
2035 }
2036
2037 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2038 {
2039 struct dso *current;
2040 struct dl_phdr_info info;
2041 int ret = 0;
2042 for(current = head; current;) {
2043 info.dlpi_addr = (uintptr_t)current->base;
2044 info.dlpi_name = current->name;
2045 info.dlpi_phdr = current->phdr;
2046 info.dlpi_phnum = current->phnum;
2047 info.dlpi_adds = gencnt;
2048 info.dlpi_subs = 0;
2049 info.dlpi_tls_modid = current->tls_id;
2050 info.dlpi_tls_data = current->tls.image;
2051
2052 ret = (callback)(&info, sizeof (info), data);
2053
2054 if (ret != 0) break;
2055
2056 pthread_rwlock_rdlock(&lock);
2057 current = current->next;
2058 pthread_rwlock_unlock(&lock);
2059 }
2060 return ret;
2061 }
2062
2063 static void error(const char *fmt, ...)
2064 {
2065 va_list ap;
2066 va_start(ap, fmt);
2067 if (!runtime) {
2068 vdprintf(2, fmt, ap);
2069 dprintf(2, "\n");
2070 ldso_fail = 1;
2071 va_end(ap);
2072 return;
2073 }
2074 __dl_vseterr(fmt, ap);
2075 va_end(ap);
2076 }
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