1 #define _GNU_SOURCE
2 #define SYSCALL_NO_TLS 1
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 <semaphore.h>
21 #include <sys/membarrier.h>
22 #include "pthread_impl.h"
23 #include "fork_impl.h"
24 #include "dynlink.h"
25
26 static size_t ldso_page_size;
27 #ifndef PAGE_SIZE
28 #define PAGE_SIZE ldso_page_size
29 #endif
30
31 #include "libc.h"
32
33 #define malloc __libc_malloc
34 #define calloc __libc_calloc
35 #define realloc __libc_realloc
36 #define free __libc_free
37
38 static void error_impl(const char *, ...);
39 static void error_noop(const char *, ...);
40 static void (*error)(const char *, ...) = error_noop;
41
42 #define MAXP2(a,b) (-(-(a)&-(b)))
43 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
44
45 #define container_of(p,t,m) ((t*)((char *)(p)-offsetof(t,m)))
46 #define countof(a) ((sizeof (a))/(sizeof (a)[0]))
47
48 struct debug {
49 int ver;
50 void *head;
51 void (*bp)(void);
52 int state;
53 void *base;
54 };
55
56 struct td_index {
57 size_t args[2];
58 struct td_index *next;
59 };
60
61 struct dso {
62 #if DL_FDPIC
63 struct fdpic_loadmap *loadmap;
64 #else
65 unsigned char *base;
66 #endif
67 char *name;
68 size_t *dynv;
69 struct dso *next, *prev;
70
71 Phdr *phdr;
72 int phnum;
73 size_t phentsize;
74 Sym *syms;
75 Elf_Symndx *hashtab;
76 uint32_t *ghashtab;
77 int16_t *versym;
78 char *strings;
79 struct dso *syms_next, *lazy_next;
80 size_t *lazy, lazy_cnt;
81 unsigned char *map;
82 size_t map_len;
83 #ifndef __LITEOS_A__
84 dev_t dev;
85 ino_t ino;
86 #endif
87 char relocated;
88 char constructed;
89 char kernel_mapped;
90 char mark;
91 char bfs_built;
92 char runtime_loaded;
93 struct dso **deps, *needed_by;
94 size_t ndeps_direct;
95 size_t next_dep;
96 pthread_t ctor_visitor;
97 char *rpath_orig, *rpath;
98 struct tls_module tls;
99 size_t tls_id;
100 size_t relro_start, relro_end;
101 uintptr_t *new_dtv;
102 unsigned char *new_tls;
103 struct td_index *td_index;
104 struct dso *fini_next;
105 char *shortname;
106 #if DL_FDPIC
107 unsigned char *base;
108 #else
109 struct fdpic_loadmap *loadmap;
110 #endif
111 struct funcdesc {
112 void *addr;
113 size_t *got;
114 } *funcdescs;
115 size_t *got;
116 char buf[];
117 };
118
119 struct symdef {
120 Sym *sym;
121 struct dso *dso;
122 };
123
124 typedef void (*stage3_func)(size_t *, size_t *);
125
126 static struct builtin_tls {
127 char c;
128 struct pthread pt;
129 void *space[16];
130 } builtin_tls[1];
131 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
132
133 #define ADDEND_LIMIT 4096
134 static size_t *saved_addends, *apply_addends_to;
135
136 static struct dso ldso;
137 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
138 static char *env_path, *sys_path;
139 static unsigned long long gencnt;
140 static int runtime;
141 static int ldd_mode;
142 static int ldso_fail;
143 static int noload;
144 static int shutting_down;
145 static jmp_buf *rtld_fail;
146 static pthread_rwlock_t lock;
147 static struct debug debug;
148 static struct tls_module *tls_tail;
149 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
150 static size_t static_tls_cnt;
151 static pthread_mutex_t init_fini_lock;
152 static pthread_cond_t ctor_cond;
153 static struct dso *builtin_deps[2];
154 static struct dso *const no_deps[1];
155 static struct dso *builtin_ctor_queue[4];
156 static struct dso **main_ctor_queue;
157 static struct fdpic_loadmap *app_loadmap;
158 static struct fdpic_dummy_loadmap app_dummy_loadmap;
159
160 struct debug *_dl_debug_addr = &debug;
161
162 extern weak hidden char __ehdr_start[];
163
164 extern hidden int __malloc_replaced;
165
166 hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
167
168 extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
169
170 weak_alias(__init_array_start, __init_array_end);
171 weak_alias(__fini_array_start, __fini_array_end);
172
dl_strcmp(const char * l,const char * r)173 static int dl_strcmp(const char *l, const char *r)
174 {
175 for (; *l==*r && *l; l++, r++);
176 return *(unsigned char *)l - *(unsigned char *)r;
177 }
178 #define strcmp(l,r) dl_strcmp(l,r)
179
180 /* Compute load address for a virtual address in a given dso. */
181 #if DL_FDPIC
laddr(const struct dso * p,size_t v)182 static void *laddr(const struct dso *p, size_t v)
183 {
184 size_t j=0;
185 if (!p->loadmap) return p->base + v;
186 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
187 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
188 }
laddr_pg(const struct dso * p,size_t v)189 static void *laddr_pg(const struct dso *p, size_t v)
190 {
191 size_t j=0;
192 size_t pgsz = PAGE_SIZE;
193 if (!p->loadmap) return p->base + v;
194 for (j=0; ; j++) {
195 size_t a = p->loadmap->segs[j].p_vaddr;
196 size_t b = a + p->loadmap->segs[j].p_memsz;
197 a &= -pgsz;
198 b += pgsz-1;
199 b &= -pgsz;
200 if (v-a<b-a) break;
201 }
202 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
203 }
fdbarrier(void * p)204 static void (*fdbarrier(void *p))()
205 {
206 void (*fd)();
207 __asm__("" : "=r"(fd) : "0"(p));
208 return fd;
209 }
210 #define fpaddr(p, v) fdbarrier((&(struct funcdesc){ \
211 laddr(p, v), (p)->got }))
212 #else
213 #define laddr(p, v) (void *)((p)->base + (v))
214 #define laddr_pg(p, v) laddr(p, v)
215 #define fpaddr(p, v) ((void (*)())laddr(p, v))
216 #endif
217
decode_vec(size_t * v,size_t * a,size_t cnt)218 static void decode_vec(size_t *v, size_t *a, size_t cnt)
219 {
220 size_t i;
221 for (i=0; i<cnt; i++) a[i] = 0;
222 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
223 if (v[0] < 8*sizeof(long))
224 a[0] |= 1UL<<v[0];
225 a[v[0]] = v[1];
226 }
227 }
228
search_vec(size_t * v,size_t * r,size_t key)229 static int search_vec(size_t *v, size_t *r, size_t key)
230 {
231 for (; v[0]!=key; v+=2)
232 if (!v[0]) return 0;
233 *r = v[1];
234 return 1;
235 }
236
sysv_hash(const char * s0)237 static uint32_t sysv_hash(const char *s0)
238 {
239 const unsigned char *s = (void *)s0;
240 uint_fast32_t h = 0;
241 while (*s) {
242 h = 16*h + *s++;
243 h ^= h>>24 & 0xf0;
244 }
245 return h & 0xfffffff;
246 }
247
gnu_hash(const char * s0)248 static uint32_t gnu_hash(const char *s0)
249 {
250 const unsigned char *s = (void *)s0;
251 uint_fast32_t h = 5381;
252 for (; *s; s++)
253 h += h*32 + *s;
254 return h;
255 }
256
sysv_lookup(const char * s,uint32_t h,struct dso * dso)257 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
258 {
259 size_t i;
260 Sym *syms = dso->syms;
261 Elf_Symndx *hashtab = dso->hashtab;
262 char *strings = dso->strings;
263 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
264 if ((!dso->versym || dso->versym[i] >= 0)
265 && (!strcmp(s, strings+syms[i].st_name)))
266 return syms+i;
267 }
268 return 0;
269 }
270
gnu_lookup(uint32_t h1,uint32_t * hashtab,struct dso * dso,const char * s)271 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
272 {
273 uint32_t nbuckets = hashtab[0];
274 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
275 uint32_t i = buckets[h1 % nbuckets];
276
277 if (!i) return 0;
278
279 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
280
281 for (h1 |= 1; ; i++) {
282 uint32_t h2 = *hashval++;
283 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
284 && !strcmp(s, dso->strings + dso->syms[i].st_name))
285 return dso->syms+i;
286 if (h2 & 1) break;
287 }
288
289 return 0;
290 }
291
gnu_lookup_filtered(uint32_t h1,uint32_t * hashtab,struct dso * dso,const char * s,uint32_t fofs,size_t fmask)292 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
293 {
294 const size_t *bloomwords = (const void *)(hashtab+4);
295 size_t f = bloomwords[fofs & (hashtab[2]-1)];
296 if (!(f & fmask)) return 0;
297
298 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
299 if (!(f & 1)) return 0;
300
301 return gnu_lookup(h1, hashtab, dso, s);
302 }
303
304 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
305 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
306
307 #ifndef ARCH_SYM_REJECT_UND
308 #define ARCH_SYM_REJECT_UND(s) 0
309 #endif
310
311 #if defined(__GNUC__)
312 __attribute__((always_inline))
313 #endif
find_sym2(struct dso * dso,const char * s,int need_def,int use_deps)314 static inline struct symdef find_sym2(struct dso *dso, const char *s, int need_def, int use_deps)
315 {
316 uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
317 size_t ghm = 1ul << gh % (8*sizeof(size_t));
318 struct symdef def = {0};
319 struct dso **deps = use_deps ? dso->deps : 0;
320 for (; dso; dso=use_deps ? *deps++ : dso->syms_next) {
321 Sym *sym;
322 if ((ght = dso->ghashtab)) {
323 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
324 } else {
325 if (!h) h = sysv_hash(s);
326 sym = sysv_lookup(s, h, dso);
327 }
328 if (!sym) continue;
329 if (!sym->st_shndx)
330 if (need_def || (sym->st_info&0xf) == STT_TLS
331 || ARCH_SYM_REJECT_UND(sym))
332 continue;
333 if (!sym->st_value)
334 if ((sym->st_info&0xf) != STT_TLS)
335 continue;
336 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
337 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
338 def.sym = sym;
339 def.dso = dso;
340 break;
341 }
342 return def;
343 }
344
find_sym(struct dso * dso,const char * s,int need_def)345 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
346 {
347 return find_sym2(dso, s, need_def, 0);
348 }
349
get_lfs64(const char * name)350 static struct symdef get_lfs64(const char *name)
351 {
352 const char *p;
353 static const char lfs64_list[] =
354 "aio_cancel\0aio_error\0aio_fsync\0aio_read\0aio_return\0"
355 "aio_suspend\0aio_write\0alphasort\0creat\0fallocate\0"
356 "fgetpos\0fopen\0freopen\0fseeko\0fsetpos\0fstat\0"
357 "fstatat\0fstatfs\0fstatvfs\0ftello\0ftruncate\0ftw\0"
358 "getdents\0getrlimit\0glob\0globfree\0lio_listio\0"
359 "lockf\0lseek\0lstat\0mkostemp\0mkostemps\0mkstemp\0"
360 "mkstemps\0mmap\0nftw\0open\0openat\0posix_fadvise\0"
361 "posix_fallocate\0pread\0preadv\0prlimit\0pwrite\0"
362 "pwritev\0readdir\0scandir\0sendfile\0setrlimit\0"
363 "stat\0statfs\0statvfs\0tmpfile\0truncate\0versionsort\0"
364 "__fxstat\0__fxstatat\0__lxstat\0__xstat\0";
365 size_t l;
366 char buf[16];
367 for (l=0; name[l]; l++) {
368 if (l >= sizeof buf) goto nomatch;
369 buf[l] = name[l];
370 }
371 if (!strcmp(name, "readdir64_r"))
372 return find_sym(&ldso, "readdir_r", 1);
373 if (l<2 || name[l-2]!='6' || name[l-1]!='4')
374 goto nomatch;
375 buf[l-=2] = 0;
376 for (p=lfs64_list; *p; p++) {
377 if (!strcmp(buf, p)) return find_sym(&ldso, buf, 1);
378 while (*p) p++;
379 }
380 nomatch:
381 return (struct symdef){ 0 };
382 }
383
do_relocs(struct dso * dso,size_t * rel,size_t rel_size,size_t stride)384 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
385 {
386 unsigned char *base = dso->base;
387 Sym *syms = dso->syms;
388 char *strings = dso->strings;
389 Sym *sym;
390 const char *name;
391 void *ctx;
392 int type;
393 int sym_index;
394 struct symdef def;
395 size_t *reloc_addr;
396 size_t sym_val;
397 size_t tls_val;
398 size_t addend;
399 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
400
401 if (dso == &ldso) {
402 /* Only ldso's REL table needs addend saving/reuse. */
403 if (rel == apply_addends_to)
404 reuse_addends = 1;
405 skip_relative = 1;
406 }
407
408 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
409 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
410 type = R_TYPE(rel[1]);
411 if (type == REL_NONE) continue;
412 reloc_addr = laddr(dso, rel[0]);
413
414 if (stride > 2) {
415 addend = rel[2];
416 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
417 addend = 0;
418 } else if (reuse_addends) {
419 /* Save original addend in stage 2 where the dso
420 * chain consists of just ldso; otherwise read back
421 * saved addend since the inline one was clobbered. */
422 if (head==&ldso)
423 saved_addends[save_slot] = *reloc_addr;
424 addend = saved_addends[save_slot++];
425 } else {
426 addend = *reloc_addr;
427 }
428
429 sym_index = R_SYM(rel[1]);
430 if (sym_index) {
431 sym = syms + sym_index;
432 name = strings + sym->st_name;
433 ctx = type==REL_COPY ? head->syms_next : head;
434 def = (sym->st_info>>4) == STB_LOCAL
435 ? (struct symdef){ .dso = dso, .sym = sym }
436 : find_sym(ctx, name, type==REL_PLT);
437 if (!def.sym && (sym->st_shndx != SHN_UNDEF
438 || sym->st_info>>4 != STB_WEAK)) {
439 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
440 dso->lazy[3*dso->lazy_cnt+0] = rel[0];
441 dso->lazy[3*dso->lazy_cnt+1] = rel[1];
442 dso->lazy[3*dso->lazy_cnt+2] = addend;
443 dso->lazy_cnt++;
444 continue;
445 }
446 error("Error relocating %s: %s: symbol not found",
447 dso->name, name);
448 if (runtime) longjmp(*rtld_fail, 1);
449 continue;
450 }
451 } else {
452 sym = 0;
453 def.sym = 0;
454 def.dso = dso;
455 }
456
457 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
458 tls_val = def.sym ? def.sym->st_value : 0;
459
460 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
461 && def.dso->tls_id > static_tls_cnt) {
462 error("Error relocating %s: %s: initial-exec TLS "
463 "resolves to dynamic definition in %s",
464 dso->name, name, def.dso->name);
465 longjmp(*rtld_fail, 1);
466 }
467
468 switch(type) {
469 case REL_OFFSET:
470 addend -= (size_t)reloc_addr;
471 case REL_SYMBOLIC:
472 case REL_GOT:
473 case REL_PLT:
474 *reloc_addr = sym_val + addend;
475 break;
476 case REL_USYMBOLIC:
477 memcpy(reloc_addr, &(size_t){sym_val + addend}, sizeof(size_t));
478 break;
479 case REL_RELATIVE:
480 *reloc_addr = (size_t)base + addend;
481 break;
482 case REL_SYM_OR_REL:
483 if (sym) *reloc_addr = sym_val + addend;
484 else *reloc_addr = (size_t)base + addend;
485 break;
486 case REL_COPY:
487 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
488 break;
489 case REL_OFFSET32:
490 *(uint32_t *)reloc_addr = sym_val + addend
491 - (size_t)reloc_addr;
492 break;
493 case REL_FUNCDESC:
494 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
495 + (def.sym - def.dso->syms)) : 0;
496 break;
497 case REL_FUNCDESC_VAL:
498 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
499 else *reloc_addr = sym_val;
500 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
501 break;
502 case REL_DTPMOD:
503 *reloc_addr = def.dso->tls_id;
504 break;
505 case REL_DTPOFF:
506 *reloc_addr = tls_val + addend - DTP_OFFSET;
507 break;
508 #ifdef TLS_ABOVE_TP
509 case REL_TPOFF:
510 *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
511 break;
512 #else
513 case REL_TPOFF:
514 *reloc_addr = tls_val - def.dso->tls.offset + addend;
515 break;
516 case REL_TPOFF_NEG:
517 *reloc_addr = def.dso->tls.offset - tls_val + addend;
518 break;
519 #endif
520 case REL_TLSDESC:
521 if (stride<3) addend = reloc_addr[!TLSDESC_BACKWARDS];
522 if (def.dso->tls_id > static_tls_cnt) {
523 struct td_index *new = malloc(sizeof *new);
524 if (!new) {
525 error(
526 "Error relocating %s: cannot allocate TLSDESC for %s",
527 dso->name, sym ? name : "(local)" );
528 longjmp(*rtld_fail, 1);
529 }
530 new->next = dso->td_index;
531 dso->td_index = new;
532 new->args[0] = def.dso->tls_id;
533 new->args[1] = tls_val + addend - DTP_OFFSET;
534 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
535 reloc_addr[1] = (size_t)new;
536 } else {
537 reloc_addr[0] = (size_t)__tlsdesc_static;
538 #ifdef TLS_ABOVE_TP
539 reloc_addr[1] = tls_val + def.dso->tls.offset
540 + TPOFF_K + addend;
541 #else
542 reloc_addr[1] = tls_val - def.dso->tls.offset
543 + addend;
544 #endif
545 }
546 /* Some archs (32-bit ARM at least) invert the order of
547 * the descriptor members. Fix them up here. */
548 if (TLSDESC_BACKWARDS) {
549 size_t tmp = reloc_addr[0];
550 reloc_addr[0] = reloc_addr[1];
551 reloc_addr[1] = tmp;
552 }
553 break;
554 default:
555 error("Error relocating %s: unsupported relocation type %d",
556 dso->name, type);
557 if (runtime) longjmp(*rtld_fail, 1);
558 continue;
559 }
560 }
561 }
562
do_relr_relocs(struct dso * dso,size_t * relr,size_t relr_size)563 static void do_relr_relocs(struct dso *dso, size_t *relr, size_t relr_size)
564 {
565 if (dso == &ldso) return; /* self-relocation was done in _dlstart */
566 unsigned char *base = dso->base;
567 size_t *reloc_addr;
568 for (; relr_size; relr++, relr_size-=sizeof(size_t))
569 if ((relr[0]&1) == 0) {
570 reloc_addr = laddr(dso, relr[0]);
571 *reloc_addr++ += (size_t)base;
572 } else {
573 int i = 0;
574 for (size_t bitmap=relr[0]; (bitmap>>=1); i++)
575 if (bitmap&1)
576 reloc_addr[i] += (size_t)base;
577 reloc_addr += 8*sizeof(size_t)-1;
578 }
579 }
580
redo_lazy_relocs()581 static void redo_lazy_relocs()
582 {
583 struct dso *p = lazy_head, *next;
584 lazy_head = 0;
585 for (; p; p=next) {
586 next = p->lazy_next;
587 size_t size = p->lazy_cnt*3*sizeof(size_t);
588 p->lazy_cnt = 0;
589 do_relocs(p, p->lazy, size, 3);
590 if (p->lazy_cnt) {
591 p->lazy_next = lazy_head;
592 lazy_head = p;
593 } else {
594 free(p->lazy);
595 p->lazy = 0;
596 p->lazy_next = 0;
597 }
598 }
599 }
600
601 /* A huge hack: to make up for the wastefulness of shared libraries
602 * needing at least a page of dirty memory even if they have no global
603 * data, we reclaim the gaps at the beginning and end of writable maps
604 * and "donate" them to the heap. */
605
reclaim(struct dso * dso,size_t start,size_t end)606 static void reclaim(struct dso *dso, size_t start, size_t end)
607 {
608 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
609 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
610 if (start >= end) return;
611 char *base = laddr_pg(dso, start);
612 __malloc_donate(base, base+(end-start));
613 }
614
reclaim_gaps(struct dso * dso)615 static void reclaim_gaps(struct dso *dso)
616 {
617 Phdr *ph = dso->phdr;
618 size_t phcnt = dso->phnum;
619
620 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
621 if (ph->p_type!=PT_LOAD) continue;
622 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
623 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
624 reclaim(dso, ph->p_vaddr+ph->p_memsz,
625 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
626 }
627 }
628
read_loop(int fd,void * p,size_t n)629 static ssize_t read_loop(int fd, void *p, size_t n)
630 {
631 for (size_t i=0; i<n; ) {
632 ssize_t l = read(fd, (char *)p+i, n-i);
633 if (l<0) {
634 if (errno==EINTR) continue;
635 else return -1;
636 }
637 if (l==0) return i;
638 i += l;
639 }
640 return n;
641 }
642
mmap_fixed(void * p,size_t n,int prot,int flags,int fd,off_t off)643 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
644 {
645 static int no_map_fixed;
646 char *q;
647 if (!n) return p;
648 if (!no_map_fixed) {
649 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
650 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
651 return q;
652 no_map_fixed = 1;
653 }
654 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
655 if (flags & MAP_ANONYMOUS) {
656 memset(p, 0, n);
657 return p;
658 }
659 ssize_t r;
660 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
661 for (q=p; n; q+=r, off+=r, n-=r) {
662 r = read(fd, q, n);
663 if (r < 0 && errno != EINTR) return MAP_FAILED;
664 if (!r) {
665 memset(q, 0, n);
666 break;
667 }
668 }
669 return p;
670 }
671
unmap_library(struct dso * dso)672 static void unmap_library(struct dso *dso)
673 {
674 if (dso->loadmap) {
675 size_t i;
676 for (i=0; i<dso->loadmap->nsegs; i++) {
677 if (!dso->loadmap->segs[i].p_memsz)
678 continue;
679 munmap((void *)dso->loadmap->segs[i].addr,
680 dso->loadmap->segs[i].p_memsz);
681 }
682 free(dso->loadmap);
683 } else if (dso->map && dso->map_len) {
684 munmap(dso->map, dso->map_len);
685 }
686 }
687
map_library(int fd,struct dso * dso)688 static void *map_library(int fd, struct dso *dso)
689 {
690 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
691 void *allocated_buf=0;
692 size_t phsize;
693 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
694 size_t this_min, this_max;
695 size_t nsegs = 0;
696 off_t off_start;
697 Ehdr *eh;
698 Phdr *ph, *ph0;
699 unsigned prot;
700 unsigned char *map=MAP_FAILED, *base;
701 size_t dyn=0;
702 size_t tls_image=0;
703 size_t i;
704
705 ssize_t l = read(fd, buf, sizeof buf);
706 eh = buf;
707 if (l<0) return 0;
708 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
709 goto noexec;
710 phsize = eh->e_phentsize * eh->e_phnum;
711 if (phsize > sizeof buf - sizeof *eh) {
712 allocated_buf = malloc(phsize);
713 if (!allocated_buf) return 0;
714 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
715 if (l < 0) goto error;
716 if (l != phsize) goto noexec;
717 ph = ph0 = allocated_buf;
718 } else if (eh->e_phoff + phsize > l) {
719 l = pread(fd, buf+1, phsize, eh->e_phoff);
720 if (l < 0) goto error;
721 if (l != phsize) goto noexec;
722 ph = ph0 = (void *)(buf + 1);
723 } else {
724 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
725 }
726 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
727 if (ph->p_type == PT_DYNAMIC) {
728 dyn = ph->p_vaddr;
729 } else if (ph->p_type == PT_TLS) {
730 tls_image = ph->p_vaddr;
731 dso->tls.align = ph->p_align;
732 dso->tls.len = ph->p_filesz;
733 dso->tls.size = ph->p_memsz;
734 } else if (ph->p_type == PT_GNU_RELRO) {
735 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
736 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
737 } else if (ph->p_type == PT_GNU_STACK) {
738 if (!runtime && ph->p_memsz > __default_stacksize) {
739 __default_stacksize =
740 ph->p_memsz < DEFAULT_STACK_MAX ?
741 ph->p_memsz : DEFAULT_STACK_MAX;
742 }
743 }
744 if (ph->p_type != PT_LOAD) continue;
745 nsegs++;
746 if (ph->p_vaddr < addr_min) {
747 addr_min = ph->p_vaddr;
748 off_start = ph->p_offset;
749 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
750 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
751 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
752 }
753 if (ph->p_vaddr+ph->p_memsz > addr_max) {
754 addr_max = ph->p_vaddr+ph->p_memsz;
755 }
756 }
757 if (!dyn) goto noexec;
758 if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
759 dso->loadmap = calloc(1, sizeof *dso->loadmap
760 + nsegs * sizeof *dso->loadmap->segs);
761 if (!dso->loadmap) goto error;
762 dso->loadmap->nsegs = nsegs;
763 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
764 if (ph->p_type != PT_LOAD) continue;
765 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
766 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
767 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
768 map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
769 prot, MAP_PRIVATE,
770 fd, ph->p_offset & -PAGE_SIZE);
771 if (map == MAP_FAILED) {
772 unmap_library(dso);
773 goto error;
774 }
775 dso->loadmap->segs[i].addr = (size_t)map +
776 (ph->p_vaddr & PAGE_SIZE-1);
777 dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
778 dso->loadmap->segs[i].p_memsz = ph->p_memsz;
779 i++;
780 if (prot & PROT_WRITE) {
781 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
782 + ph->p_filesz;
783 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
784 size_t pgend = brk + ph->p_memsz - ph->p_filesz
785 + PAGE_SIZE-1 & -PAGE_SIZE;
786 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
787 pgend-pgbrk, prot,
788 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
789 -1, off_start) == MAP_FAILED)
790 goto error;
791 memset(map + brk, 0, pgbrk-brk);
792 }
793 }
794 map = (void *)dso->loadmap->segs[0].addr;
795 map_len = 0;
796 goto done_mapping;
797 }
798 addr_max += PAGE_SIZE-1;
799 addr_max &= -PAGE_SIZE;
800 addr_min &= -PAGE_SIZE;
801 off_start &= -PAGE_SIZE;
802 map_len = addr_max - addr_min + off_start;
803 /* The first time, we map too much, possibly even more than
804 * the length of the file. This is okay because we will not
805 * use the invalid part; we just need to reserve the right
806 * amount of virtual address space to map over later. */
807 map = DL_NOMMU_SUPPORT
808 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
809 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
810 : mmap((void *)addr_min, map_len, prot,
811 MAP_PRIVATE, fd, off_start);
812 if (map==MAP_FAILED) goto error;
813 dso->map = map;
814 dso->map_len = map_len;
815 /* If the loaded file is not relocatable and the requested address is
816 * not available, then the load operation must fail. */
817 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
818 errno = EBUSY;
819 goto error;
820 }
821 base = map - addr_min;
822 dso->phdr = 0;
823 dso->phnum = 0;
824 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
825 if (ph->p_type != PT_LOAD) continue;
826 /* Check if the programs headers are in this load segment, and
827 * if so, record the address for use by dl_iterate_phdr. */
828 if (!dso->phdr && eh->e_phoff >= ph->p_offset
829 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
830 dso->phdr = (void *)(base + ph->p_vaddr
831 + (eh->e_phoff-ph->p_offset));
832 dso->phnum = eh->e_phnum;
833 dso->phentsize = eh->e_phentsize;
834 }
835 this_min = ph->p_vaddr & -PAGE_SIZE;
836 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
837 off_start = ph->p_offset & -PAGE_SIZE;
838 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
839 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
840 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
841 #ifdef __LITEOS_A__
842 if ((ph->p_flags & PF_R) && (ph->p_flags & PF_X) && (!(ph->p_flags & PF_W))) {
843 Phdr *next_ph = ph;
844 for (int j = i - 1; j > 0; j--) {
845 next_ph = (void *)((char *)next_ph+eh->e_phentsize);
846 if (next_ph->p_type != PT_LOAD) {
847 continue;
848 }
849 size_t p_vaddr = (next_ph->p_vaddr & -(PAGE_SIZE));
850 if (p_vaddr > this_max) {
851 mprotect(base + this_max, p_vaddr - this_max, PROT_READ);
852 }
853 break;
854 }
855 }
856 #endif
857 /* Reuse the existing mapping for the lowest-address LOAD */
858 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
859 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
860 goto error;
861 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
862 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
863 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
864 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
865 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)
866 goto error;
867 }
868 }
869 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
870 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
871 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
872 && errno != ENOSYS)
873 goto error;
874 break;
875 }
876 done_mapping:
877 dso->base = base;
878 dso->dynv = laddr(dso, dyn);
879 if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
880 free(allocated_buf);
881 return map;
882 noexec:
883 errno = ENOEXEC;
884 error:
885 if (map!=MAP_FAILED) unmap_library(dso);
886 free(allocated_buf);
887 return 0;
888 }
889
path_open(const char * name,const char * s,char * buf,size_t buf_size)890 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
891 {
892 size_t l;
893 int fd;
894 for (;;) {
895 s += strspn(s, ":\n");
896 l = strcspn(s, ":\n");
897 if (l-1 >= INT_MAX) return -1;
898 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
899 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
900 switch (errno) {
901 case ENOENT:
902 case ENOTDIR:
903 case EACCES:
904 case ENAMETOOLONG:
905 break;
906 default:
907 /* Any negative value but -1 will inhibit
908 * futher path search. */
909 return -2;
910 }
911 }
912 s += l;
913 }
914 }
915
fixup_rpath(struct dso * p,char * buf,size_t buf_size)916 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
917 {
918 size_t n, l;
919 const char *s, *t, *origin;
920 char *d;
921 if (p->rpath || !p->rpath_orig) return 0;
922 if (!strchr(p->rpath_orig, '$')) {
923 p->rpath = p->rpath_orig;
924 return 0;
925 }
926 n = 0;
927 s = p->rpath_orig;
928 while ((t=strchr(s, '$'))) {
929 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
930 return 0;
931 s = t+1;
932 n++;
933 }
934 if (n > SSIZE_MAX/PATH_MAX) return 0;
935
936 if (p->kernel_mapped) {
937 /* $ORIGIN searches cannot be performed for the main program
938 * when it is suid/sgid/AT_SECURE. This is because the
939 * pathname is under the control of the caller of execve.
940 * For libraries, however, $ORIGIN can be processed safely
941 * since the library's pathname came from a trusted source
942 * (either system paths or a call to dlopen). */
943 if (libc.secure)
944 return 0;
945 l = readlink("/proc/self/exe", buf, buf_size);
946 if (l == -1) switch (errno) {
947 case ENOENT:
948 case ENOTDIR:
949 case EACCES:
950 return 0;
951 default:
952 return -1;
953 }
954 if (l >= buf_size)
955 return 0;
956 buf[l] = 0;
957 origin = buf;
958 } else {
959 origin = p->name;
960 }
961 t = strrchr(origin, '/');
962 if (t) {
963 l = t-origin;
964 } else {
965 /* Normally p->name will always be an absolute or relative
966 * pathname containing at least one '/' character, but in the
967 * case where ldso was invoked as a command to execute a
968 * program in the working directory, app.name may not. Fix. */
969 origin = ".";
970 l = 1;
971 }
972 /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
973 if (libc.secure && *origin != '/')
974 return 0;
975 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
976 if (!p->rpath) return -1;
977
978 d = p->rpath;
979 s = p->rpath_orig;
980 while ((t=strchr(s, '$'))) {
981 memcpy(d, s, t-s);
982 d += t-s;
983 memcpy(d, origin, l);
984 d += l;
985 /* It was determined previously that the '$' is followed
986 * either by "ORIGIN" or "{ORIGIN}". */
987 s = t + 7 + 2*(t[1]=='{');
988 }
989 strcpy(d, s);
990 return 0;
991 }
992
decode_dyn(struct dso * p)993 static void decode_dyn(struct dso *p)
994 {
995 size_t dyn[DYN_CNT];
996 decode_vec(p->dynv, dyn, DYN_CNT);
997 p->syms = laddr(p, dyn[DT_SYMTAB]);
998 p->strings = laddr(p, dyn[DT_STRTAB]);
999 if (dyn[0]&(1<<DT_HASH))
1000 p->hashtab = laddr(p, dyn[DT_HASH]);
1001 if (dyn[0]&(1<<DT_RPATH))
1002 p->rpath_orig = p->strings + dyn[DT_RPATH];
1003 if (dyn[0]&(1<<DT_RUNPATH))
1004 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
1005 if (dyn[0]&(1<<DT_PLTGOT))
1006 p->got = laddr(p, dyn[DT_PLTGOT]);
1007 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
1008 p->ghashtab = laddr(p, *dyn);
1009 if (search_vec(p->dynv, dyn, DT_VERSYM))
1010 p->versym = laddr(p, *dyn);
1011 }
1012
count_syms(struct dso * p)1013 static size_t count_syms(struct dso *p)
1014 {
1015 if (p->hashtab) return p->hashtab[1];
1016
1017 size_t nsym, i;
1018 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1019 uint32_t *hashval;
1020 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1021 if (buckets[i] > nsym)
1022 nsym = buckets[i];
1023 }
1024 if (nsym) {
1025 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
1026 do nsym++;
1027 while (!(*hashval++ & 1));
1028 }
1029 return nsym;
1030 }
1031
dl_mmap(size_t n)1032 static void *dl_mmap(size_t n)
1033 {
1034 void *p;
1035 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
1036 #ifdef SYS_mmap2
1037 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
1038 #else
1039 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
1040 #endif
1041 return (unsigned long)p > -4096UL ? 0 : p;
1042 }
1043
makefuncdescs(struct dso * p)1044 static void makefuncdescs(struct dso *p)
1045 {
1046 static int self_done;
1047 size_t nsym = count_syms(p);
1048 size_t i, size = nsym * sizeof(*p->funcdescs);
1049
1050 if (!self_done) {
1051 p->funcdescs = dl_mmap(size);
1052 self_done = 1;
1053 } else {
1054 p->funcdescs = malloc(size);
1055 }
1056 if (!p->funcdescs) {
1057 if (!runtime) a_crash();
1058 error("Error allocating function descriptors for %s", p->name);
1059 longjmp(*rtld_fail, 1);
1060 }
1061 for (i=0; i<nsym; i++) {
1062 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
1063 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
1064 p->funcdescs[i].got = p->got;
1065 } else {
1066 p->funcdescs[i].addr = 0;
1067 p->funcdescs[i].got = 0;
1068 }
1069 }
1070 }
1071
load_library(const char * name,struct dso * needed_by)1072 static struct dso *load_library(const char *name, struct dso *needed_by)
1073 {
1074 char buf[2*NAME_MAX+2];
1075 #ifdef __LITEOS_A__
1076 char fullpath[2*NAME_MAX+2];
1077 #endif
1078 const char *pathname;
1079 unsigned char *map;
1080 struct dso *p, temp_dso = {0};
1081 int fd;
1082 struct stat st;
1083 size_t alloc_size;
1084 int n_th = 0;
1085 int is_self = 0;
1086
1087 if (!*name) {
1088 errno = EINVAL;
1089 return 0;
1090 }
1091
1092 /* Catch and block attempts to reload the implementation itself */
1093 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
1094 static const char reserved[] =
1095 "c.pthread.rt.m.dl.util.xnet.";
1096 const char *rp, *next;
1097 for (rp=reserved; *rp; rp=next) {
1098 next = strchr(rp, '.') + 1;
1099 if (strncmp(name+3, rp, next-rp) == 0)
1100 break;
1101 }
1102 if (*rp) {
1103 if (ldd_mode) {
1104 /* Track which names have been resolved
1105 * and only report each one once. */
1106 static unsigned reported;
1107 unsigned mask = 1U<<(rp-reserved);
1108 if (!(reported & mask)) {
1109 reported |= mask;
1110 dprintf(1, "\t%s => %s (%p)\n",
1111 name, ldso.name,
1112 ldso.base);
1113 }
1114 }
1115 is_self = 1;
1116 }
1117 }
1118 if (!strcmp(name, ldso.name)) is_self = 1;
1119 if (is_self) {
1120 if (!ldso.prev) {
1121 tail->next = &ldso;
1122 ldso.prev = tail;
1123 tail = &ldso;
1124 }
1125 return &ldso;
1126 }
1127 if (strchr(name, '/')) {
1128 pathname = name;
1129 fd = open(name, O_RDONLY|O_CLOEXEC);
1130 } else {
1131 /* Search for the name to see if it's already loaded */
1132 for (p=head->next; p; p=p->next) {
1133 if (p->shortname && !strcmp(p->shortname, name)) {
1134 return p;
1135 }
1136 }
1137 if (strlen(name) > NAME_MAX) return 0;
1138 fd = -1;
1139 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
1140 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
1141 if (fixup_rpath(p, buf, sizeof buf) < 0)
1142 fd = -2; /* Inhibit further search. */
1143 if (p->rpath)
1144 fd = path_open(name, p->rpath, buf, sizeof buf);
1145 }
1146 if (fd == -1) {
1147 if (!sys_path) {
1148 char *prefix = 0;
1149 size_t prefix_len;
1150 if (ldso.name[0]=='/') {
1151 char *s, *t, *z;
1152 for (s=t=z=ldso.name; *s; s++)
1153 if (*s=='/') z=t, t=s;
1154 prefix_len = z-ldso.name;
1155 if (prefix_len < PATH_MAX)
1156 prefix = ldso.name;
1157 }
1158 if (!prefix) {
1159 prefix = "";
1160 prefix_len = 0;
1161 }
1162 char etc_ldso_path[prefix_len + 1
1163 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1164 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1165 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1166 (int)prefix_len, prefix);
1167 fd = open(etc_ldso_path, O_RDONLY|O_CLOEXEC);
1168 if (fd>=0) {
1169 size_t n = 0;
1170 if (!fstat(fd, &st)) n = st.st_size;
1171 if ((sys_path = malloc(n+1)))
1172 sys_path[n] = 0;
1173 if (!sys_path || read_loop(fd, sys_path, n)<0) {
1174 free(sys_path);
1175 sys_path = "";
1176 }
1177 close(fd);
1178 } else if (errno != ENOENT) {
1179 sys_path = "";
1180 }
1181 }
1182 #ifdef __LITEOS_A__
1183 if (!sys_path || sys_path[0] == 0) {
1184 sys_path = "/usr/lib:/lib:/usr/local/lib";
1185 }
1186 #else
1187 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1188 #endif
1189 fd = path_open(name, sys_path, buf, sizeof buf);
1190 }
1191 pathname = buf;
1192 }
1193 if (fd < 0) return 0;
1194 #ifdef __LITEOS_A__
1195 if (pathname[0] != '/') {
1196 if (!realpath(pathname, fullpath)) {
1197 close(fd);
1198 return 0;
1199 }
1200 pathname = fullpath;
1201 }
1202 #else
1203 if (fstat(fd, &st) < 0) {
1204 close(fd);
1205 return 0;
1206 }
1207 #endif
1208 for (p=head->next; p; p=p->next) {
1209 #ifdef __LITEOS_A__
1210 if (!strcmp(p->name, pathname)) {
1211 #else
1212 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1213 #endif
1214 /* If this library was previously loaded with a
1215 * pathname but a search found the same inode,
1216 * setup its shortname so it can be found by name. */
1217 if (!p->shortname && pathname != name)
1218 p->shortname = strrchr(p->name, '/')+1;
1219 close(fd);
1220 return p;
1221 }
1222 }
1223 map = noload ? 0 : map_library(fd, &temp_dso);
1224 close(fd);
1225 if (!map) return 0;
1226
1227 /* Avoid the danger of getting two versions of libc mapped into the
1228 * same process when an absolute pathname was used. The symbols
1229 * checked are chosen to catch both musl and glibc, and to avoid
1230 * false positives from interposition-hack libraries. */
1231 decode_dyn(&temp_dso);
1232 if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1233 find_sym(&temp_dso, "stdin", 1).sym) {
1234 unmap_library(&temp_dso);
1235 return load_library("libc.so", needed_by);
1236 }
1237 /* Past this point, if we haven't reached runtime yet, ldso has
1238 * committed either to use the mapped library or to abort execution.
1239 * Unmapping is not possible, so we can safely reclaim gaps. */
1240 if (!runtime) reclaim_gaps(&temp_dso);
1241
1242 /* Allocate storage for the new DSO. When there is TLS, this
1243 * storage must include a reservation for all pre-existing
1244 * threads to obtain copies of both the new TLS, and an
1245 * extended DTV capable of storing an additional slot for
1246 * the newly-loaded DSO. */
1247 alloc_size = sizeof *p + strlen(pathname) + 1;
1248 if (runtime && temp_dso.tls.image) {
1249 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1250 + sizeof(void *) * (tls_cnt+3);
1251 n_th = libc.threads_minus_1 + 1;
1252 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1253 else alloc_size += n_th * per_th;
1254 }
1255 p = calloc(1, alloc_size);
1256 if (!p) {
1257 unmap_library(&temp_dso);
1258 return 0;
1259 }
1260 memcpy(p, &temp_dso, sizeof temp_dso);
1261 #ifndef __LITEOS_A__
1262 p->dev = st.st_dev;
1263 p->ino = st.st_ino;
1264 #endif
1265 p->needed_by = needed_by;
1266 p->name = p->buf;
1267 p->runtime_loaded = runtime;
1268 strcpy(p->name, pathname);
1269 /* Add a shortname only if name arg was not an explicit pathname. */
1270 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1271 if (p->tls.image) {
1272 p->tls_id = ++tls_cnt;
1273 tls_align = MAXP2(tls_align, p->tls.align);
1274 #ifdef TLS_ABOVE_TP
1275 p->tls.offset = tls_offset + ( (p->tls.align-1) &
1276 (-tls_offset + (uintptr_t)p->tls.image) );
1277 tls_offset = p->tls.offset + p->tls.size;
1278 #else
1279 tls_offset += p->tls.size + p->tls.align - 1;
1280 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1281 & (p->tls.align-1);
1282 p->tls.offset = tls_offset;
1283 #endif
1284 p->new_dtv = (void *)(-sizeof(size_t) &
1285 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1286 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1287 if (tls_tail) tls_tail->next = &p->tls;
1288 else libc.tls_head = &p->tls;
1289 tls_tail = &p->tls;
1290 }
1291
1292 tail->next = p;
1293 p->prev = tail;
1294 tail = p;
1295
1296 if (DL_FDPIC) makefuncdescs(p);
1297
1298 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1299
1300 return p;
1301 }
1302
1303 static void load_direct_deps(struct dso *p)
1304 {
1305 size_t i, cnt=0;
1306
1307 if (p->deps) return;
1308 /* For head, all preloads are direct pseudo-dependencies.
1309 * Count and include them now to avoid realloc later. */
1310 if (p==head) for (struct dso *q=p->next; q; q=q->next)
1311 cnt++;
1312 for (i=0; p->dynv[i]; i+=2)
1313 if (p->dynv[i] == DT_NEEDED) cnt++;
1314 /* Use builtin buffer for apps with no external deps, to
1315 * preserve property of no runtime failure paths. */
1316 p->deps = (p==head && cnt<2) ? builtin_deps :
1317 calloc(cnt+1, sizeof *p->deps);
1318 if (!p->deps) {
1319 error("Error loading dependencies for %s", p->name);
1320 if (runtime) longjmp(*rtld_fail, 1);
1321 }
1322 cnt=0;
1323 if (p==head) for (struct dso *q=p->next; q; q=q->next)
1324 p->deps[cnt++] = q;
1325 for (i=0; p->dynv[i]; i+=2) {
1326 if (p->dynv[i] != DT_NEEDED) continue;
1327 struct dso *dep = load_library(p->strings + p->dynv[i+1], p);
1328 if (!dep) {
1329 error("Error loading shared library %s: %m (needed by %s)",
1330 p->strings + p->dynv[i+1], p->name);
1331 if (runtime) longjmp(*rtld_fail, 1);
1332 continue;
1333 }
1334 p->deps[cnt++] = dep;
1335 }
1336 p->deps[cnt] = 0;
1337 p->ndeps_direct = cnt;
1338 }
1339
1340 static void load_deps(struct dso *p)
1341 {
1342 if (p->deps) return;
1343 for (; p; p=p->next)
1344 load_direct_deps(p);
1345 }
1346
1347 static void extend_bfs_deps(struct dso *p)
1348 {
1349 size_t i, j, cnt, ndeps_all;
1350 struct dso **tmp;
1351
1352 /* Can't use realloc if the original p->deps was allocated at
1353 * program entry and malloc has been replaced, or if it's
1354 * the builtin non-allocated trivial main program deps array. */
1355 int no_realloc = (__malloc_replaced && !p->runtime_loaded)
1356 || p->deps == builtin_deps;
1357
1358 if (p->bfs_built) return;
1359 ndeps_all = p->ndeps_direct;
1360
1361 /* Mark existing (direct) deps so they won't be duplicated. */
1362 for (i=0; p->deps[i]; i++)
1363 p->deps[i]->mark = 1;
1364
1365 /* For each dependency already in the list, copy its list of direct
1366 * dependencies to the list, excluding any items already in the
1367 * list. Note that the list this loop iterates over will grow during
1368 * the loop, but since duplicates are excluded, growth is bounded. */
1369 for (i=0; p->deps[i]; i++) {
1370 struct dso *dep = p->deps[i];
1371 for (j=cnt=0; j<dep->ndeps_direct; j++)
1372 if (!dep->deps[j]->mark) cnt++;
1373 tmp = no_realloc ?
1374 malloc(sizeof(*tmp) * (ndeps_all+cnt+1)) :
1375 realloc(p->deps, sizeof(*tmp) * (ndeps_all+cnt+1));
1376 if (!tmp) {
1377 error("Error recording dependencies for %s", p->name);
1378 if (runtime) longjmp(*rtld_fail, 1);
1379 continue;
1380 }
1381 if (no_realloc) {
1382 memcpy(tmp, p->deps, sizeof(*tmp) * (ndeps_all+1));
1383 no_realloc = 0;
1384 }
1385 p->deps = tmp;
1386 for (j=0; j<dep->ndeps_direct; j++) {
1387 if (dep->deps[j]->mark) continue;
1388 dep->deps[j]->mark = 1;
1389 p->deps[ndeps_all++] = dep->deps[j];
1390 }
1391 p->deps[ndeps_all] = 0;
1392 }
1393 p->bfs_built = 1;
1394 for (p=head; p; p=p->next)
1395 p->mark = 0;
1396 }
1397
1398 static void load_preload(char *s)
1399 {
1400 int tmp;
1401 char *z;
1402 for (z=s; *z; s=z) {
1403 for ( ; *s && (isspace(*s) || *s==':'); s++);
1404 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1405 tmp = *z;
1406 *z = 0;
1407 load_library(s, 0);
1408 *z = tmp;
1409 }
1410 }
1411
1412 static void add_syms(struct dso *p)
1413 {
1414 if (!p->syms_next && syms_tail != p) {
1415 syms_tail->syms_next = p;
1416 syms_tail = p;
1417 }
1418 }
1419
1420 static void revert_syms(struct dso *old_tail)
1421 {
1422 struct dso *p, *next;
1423 /* Chop off the tail of the list of dsos that participate in
1424 * the global symbol table, reverting them to RTLD_LOCAL. */
1425 for (p=old_tail; p; p=next) {
1426 next = p->syms_next;
1427 p->syms_next = 0;
1428 }
1429 syms_tail = old_tail;
1430 }
1431
1432 static void do_mips_relocs(struct dso *p, size_t *got)
1433 {
1434 size_t i, j, rel[2];
1435 unsigned char *base = p->base;
1436 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1437 if (p==&ldso) {
1438 got += i;
1439 } else {
1440 while (i--) *got++ += (size_t)base;
1441 }
1442 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1443 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1444 Sym *sym = p->syms + j;
1445 rel[0] = (unsigned char *)got - base;
1446 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1447 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1448 do_relocs(p, rel, sizeof rel, 2);
1449 }
1450 }
1451
1452 static void reloc_all(struct dso *p)
1453 {
1454 size_t dyn[DYN_CNT];
1455 for (; p; p=p->next) {
1456 if (p->relocated) continue;
1457 decode_vec(p->dynv, dyn, DYN_CNT);
1458 if (NEED_MIPS_GOT_RELOCS)
1459 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1460 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1461 2+(dyn[DT_PLTREL]==DT_RELA));
1462 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1463 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1464 if (!DL_FDPIC)
1465 do_relr_relocs(p, laddr(p, dyn[DT_RELR]), dyn[DT_RELRSZ]);
1466
1467 if (head != &ldso && p->relro_start != p->relro_end) {
1468 long ret = __syscall(SYS_mprotect, laddr(p, p->relro_start),
1469 p->relro_end-p->relro_start, PROT_READ);
1470 if (ret != 0 && ret != -ENOSYS) {
1471 error("Error relocating %s: RELRO protection failed: %m",
1472 p->name);
1473 if (runtime) longjmp(*rtld_fail, 1);
1474 }
1475 }
1476
1477 p->relocated = 1;
1478 }
1479 }
1480
1481 static void kernel_mapped_dso(struct dso *p)
1482 {
1483 size_t min_addr = -1, max_addr = 0, cnt;
1484 Phdr *ph = p->phdr;
1485 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1486 if (ph->p_type == PT_DYNAMIC) {
1487 p->dynv = laddr(p, ph->p_vaddr);
1488 } else if (ph->p_type == PT_GNU_RELRO) {
1489 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1490 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1491 } else if (ph->p_type == PT_GNU_STACK) {
1492 if (!runtime && ph->p_memsz > __default_stacksize) {
1493 __default_stacksize =
1494 ph->p_memsz < DEFAULT_STACK_MAX ?
1495 ph->p_memsz : DEFAULT_STACK_MAX;
1496 }
1497 }
1498 if (ph->p_type != PT_LOAD) continue;
1499 if (ph->p_vaddr < min_addr)
1500 min_addr = ph->p_vaddr;
1501 if (ph->p_vaddr+ph->p_memsz > max_addr)
1502 max_addr = ph->p_vaddr+ph->p_memsz;
1503 }
1504 min_addr &= -PAGE_SIZE;
1505 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1506 p->map = p->base + min_addr;
1507 p->map_len = max_addr - min_addr;
1508 p->kernel_mapped = 1;
1509 }
1510
1511 void __libc_exit_fini()
1512 {
1513 struct dso *p;
1514 size_t dyn[DYN_CNT];
1515 pthread_t self = __pthread_self();
1516
1517 /* Take both locks before setting shutting_down, so that
1518 * either lock is sufficient to read its value. The lock
1519 * order matches that in dlopen to avoid deadlock. */
1520 pthread_rwlock_wrlock(&lock);
1521 pthread_mutex_lock(&init_fini_lock);
1522 shutting_down = 1;
1523 pthread_rwlock_unlock(&lock);
1524 for (p=fini_head; p; p=p->fini_next) {
1525 while (p->ctor_visitor && p->ctor_visitor!=self)
1526 pthread_cond_wait(&ctor_cond, &init_fini_lock);
1527 if (!p->constructed) continue;
1528 decode_vec(p->dynv, dyn, DYN_CNT);
1529 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1530 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1531 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1532 while (n--) ((void (*)(void))*--fn)();
1533 }
1534 #ifndef NO_LEGACY_INITFINI
1535 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1536 fpaddr(p, dyn[DT_FINI])();
1537 #endif
1538 }
1539 }
1540
1541 void __ldso_atfork(int who)
1542 {
1543 if (who<0) {
1544 pthread_rwlock_wrlock(&lock);
1545 pthread_mutex_lock(&init_fini_lock);
1546 } else {
1547 pthread_mutex_unlock(&init_fini_lock);
1548 pthread_rwlock_unlock(&lock);
1549 }
1550 }
1551
1552 static struct dso **queue_ctors(struct dso *dso)
1553 {
1554 size_t cnt, qpos, spos, i;
1555 struct dso *p, **queue, **stack;
1556
1557 if (ldd_mode) return 0;
1558
1559 /* Bound on queue size is the total number of indirect deps.
1560 * If a bfs deps list was built, we can use it. Otherwise,
1561 * bound by the total number of DSOs, which is always safe and
1562 * is reasonable we use it (for main app at startup). */
1563 if (dso->bfs_built) {
1564 for (cnt=0; dso->deps[cnt]; cnt++)
1565 dso->deps[cnt]->mark = 0;
1566 cnt++; /* self, not included in deps */
1567 } else {
1568 for (cnt=0, p=head; p; cnt++, p=p->next)
1569 p->mark = 0;
1570 }
1571 cnt++; /* termination slot */
1572 if (dso==head && cnt <= countof(builtin_ctor_queue))
1573 queue = builtin_ctor_queue;
1574 else
1575 queue = calloc(cnt, sizeof *queue);
1576
1577 if (!queue) {
1578 error("Error allocating constructor queue: %m\n");
1579 if (runtime) longjmp(*rtld_fail, 1);
1580 return 0;
1581 }
1582
1583 /* Opposite ends of the allocated buffer serve as an output queue
1584 * and a working stack. Setup initial stack with just the argument
1585 * dso and initial queue empty... */
1586 stack = queue;
1587 qpos = 0;
1588 spos = cnt;
1589 stack[--spos] = dso;
1590 dso->next_dep = 0;
1591 dso->mark = 1;
1592
1593 /* Then perform pseudo-DFS sort, but ignoring circular deps. */
1594 while (spos<cnt) {
1595 p = stack[spos++];
1596 while (p->next_dep < p->ndeps_direct) {
1597 if (p->deps[p->next_dep]->mark) {
1598 p->next_dep++;
1599 } else {
1600 stack[--spos] = p;
1601 p = p->deps[p->next_dep];
1602 p->next_dep = 0;
1603 p->mark = 1;
1604 }
1605 }
1606 queue[qpos++] = p;
1607 }
1608 queue[qpos] = 0;
1609 for (i=0; i<qpos; i++) queue[i]->mark = 0;
1610 for (i=0; i<qpos; i++)
1611 if (queue[i]->ctor_visitor && queue[i]->ctor_visitor->tid < 0) {
1612 error("State of %s is inconsistent due to multithreaded fork\n",
1613 queue[i]->name);
1614 free(queue);
1615 if (runtime) longjmp(*rtld_fail, 1);
1616 }
1617
1618 return queue;
1619 }
1620
1621 static void do_init_fini(struct dso **queue)
1622 {
1623 struct dso *p;
1624 size_t dyn[DYN_CNT], i;
1625 pthread_t self = __pthread_self();
1626
1627 pthread_mutex_lock(&init_fini_lock);
1628 for (i=0; (p=queue[i]); i++) {
1629 while ((p->ctor_visitor && p->ctor_visitor!=self) || shutting_down)
1630 pthread_cond_wait(&ctor_cond, &init_fini_lock);
1631 if (p->ctor_visitor || p->constructed)
1632 continue;
1633 p->ctor_visitor = self;
1634
1635 decode_vec(p->dynv, dyn, DYN_CNT);
1636 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1637 p->fini_next = fini_head;
1638 fini_head = p;
1639 }
1640
1641 pthread_mutex_unlock(&init_fini_lock);
1642
1643 #ifndef NO_LEGACY_INITFINI
1644 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1645 fpaddr(p, dyn[DT_INIT])();
1646 #endif
1647 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1648 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1649 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1650 while (n--) ((void (*)(void))*fn++)();
1651 }
1652
1653 pthread_mutex_lock(&init_fini_lock);
1654 p->ctor_visitor = 0;
1655 p->constructed = 1;
1656 pthread_cond_broadcast(&ctor_cond);
1657 }
1658 pthread_mutex_unlock(&init_fini_lock);
1659 }
1660
1661 void __libc_start_init(void)
1662 {
1663 do_init_fini(main_ctor_queue);
1664 if (!__malloc_replaced && main_ctor_queue != builtin_ctor_queue)
1665 free(main_ctor_queue);
1666 main_ctor_queue = 0;
1667 }
1668
1669 static void dl_debug_state(void)
1670 {
1671 }
1672
1673 weak_alias(dl_debug_state, _dl_debug_state);
1674
1675 void __init_tls(size_t *auxv)
1676 {
1677 }
1678
1679 static void update_tls_size()
1680 {
1681 libc.tls_cnt = tls_cnt;
1682 libc.tls_align = tls_align;
1683 libc.tls_size = ALIGN(
1684 (1+tls_cnt) * sizeof(void *) +
1685 tls_offset +
1686 sizeof(struct pthread) +
1687 tls_align * 2,
1688 tls_align);
1689 }
1690
1691 static void install_new_tls(void)
1692 {
1693 sigset_t set;
1694 pthread_t self = __pthread_self(), td;
1695 struct dso *dtv_provider = container_of(tls_tail, struct dso, tls);
1696 uintptr_t (*newdtv)[tls_cnt+1] = (void *)dtv_provider->new_dtv;
1697 struct dso *p;
1698 size_t i, j;
1699 size_t old_cnt = self->dtv[0];
1700
1701 __block_app_sigs(&set);
1702 __tl_lock();
1703 /* Copy existing dtv contents from all existing threads. */
1704 for (i=0, td=self; !i || td!=self; i++, td=td->next) {
1705 memcpy(newdtv+i, td->dtv,
1706 (old_cnt+1)*sizeof(uintptr_t));
1707 newdtv[i][0] = tls_cnt;
1708 }
1709 /* Install new dtls into the enlarged, uninstalled dtv copies. */
1710 for (p=head; ; p=p->next) {
1711 if (p->tls_id <= old_cnt) continue;
1712 unsigned char *mem = p->new_tls;
1713 for (j=0; j<i; j++) {
1714 unsigned char *new = mem;
1715 new += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1716 & (p->tls.align-1);
1717 memcpy(new, p->tls.image, p->tls.len);
1718 newdtv[j][p->tls_id] =
1719 (uintptr_t)new + DTP_OFFSET;
1720 mem += p->tls.size + p->tls.align;
1721 }
1722 if (p->tls_id == tls_cnt) break;
1723 }
1724
1725 /* Broadcast barrier to ensure contents of new dtv is visible
1726 * if the new dtv pointer is. The __membarrier function has a
1727 * fallback emulation using signals for kernels that lack the
1728 * feature at the syscall level. */
1729
1730 __membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED, 0);
1731
1732 /* Install new dtv for each thread. */
1733 for (j=0, td=self; !j || td!=self; j++, td=td->next) {
1734 td->dtv = newdtv[j];
1735 }
1736
1737 __tl_unlock();
1738 __restore_sigs(&set);
1739 }
1740
1741 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1742 * following stage 2 and stage 3 functions via primitive symbolic lookup
1743 * since it does not have access to their addresses to begin with. */
1744
1745 /* Stage 2 of the dynamic linker is called after relative relocations
1746 * have been processed. It can make function calls to static functions
1747 * and access string literals and static data, but cannot use extern
1748 * symbols. Its job is to perform symbolic relocations on the dynamic
1749 * linker itself, but some of the relocations performed may need to be
1750 * replaced later due to copy relocations in the main program. */
1751
1752 hidden void __dls2(unsigned char *base, size_t *sp)
1753 {
1754 size_t *auxv;
1755 for (auxv=sp+1+*sp+1; *auxv; auxv++);
1756 auxv++;
1757 if (DL_FDPIC) {
1758 void *p1 = (void *)sp[-2];
1759 void *p2 = (void *)sp[-1];
1760 if (!p1) {
1761 size_t aux[AUX_CNT];
1762 decode_vec(auxv, aux, AUX_CNT);
1763 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1764 else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1765 }
1766 app_loadmap = p2 ? p1 : 0;
1767 ldso.loadmap = p2 ? p2 : p1;
1768 ldso.base = laddr(&ldso, 0);
1769 } else {
1770 ldso.base = base;
1771 }
1772 Ehdr *ehdr = __ehdr_start ? (void *)__ehdr_start : (void *)ldso.base;
1773 ldso.name = ldso.shortname = "libc.so";
1774 ldso.phnum = ehdr->e_phnum;
1775 ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1776 ldso.phentsize = ehdr->e_phentsize;
1777 search_vec(auxv, &ldso_page_size, AT_PAGESZ);
1778 kernel_mapped_dso(&ldso);
1779 decode_dyn(&ldso);
1780
1781 if (DL_FDPIC) makefuncdescs(&ldso);
1782
1783 /* Prepare storage for to save clobbered REL addends so they
1784 * can be reused in stage 3. There should be very few. If
1785 * something goes wrong and there are a huge number, abort
1786 * instead of risking stack overflow. */
1787 size_t dyn[DYN_CNT];
1788 decode_vec(ldso.dynv, dyn, DYN_CNT);
1789 size_t *rel = laddr(&ldso, dyn[DT_REL]);
1790 size_t rel_size = dyn[DT_RELSZ];
1791 size_t symbolic_rel_cnt = 0;
1792 apply_addends_to = rel;
1793 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1794 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1795 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1796 size_t addends[symbolic_rel_cnt+1];
1797 saved_addends = addends;
1798
1799 head = &ldso;
1800 reloc_all(&ldso);
1801
1802 ldso.relocated = 0;
1803
1804 /* Call dynamic linker stage-2b, __dls2b, looking it up
1805 * symbolically as a barrier against moving the address
1806 * load across the above relocation processing. */
1807 struct symdef dls2b_def = find_sym(&ldso, "__dls2b", 0);
1808 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls2b_def.sym-ldso.syms])(sp, auxv);
1809 else ((stage3_func)laddr(&ldso, dls2b_def.sym->st_value))(sp, auxv);
1810 }
1811
1812 /* Stage 2b sets up a valid thread pointer, which requires relocations
1813 * completed in stage 2, and on which stage 3 is permitted to depend.
1814 * This is done as a separate stage, with symbolic lookup as a barrier,
1815 * so that loads of the thread pointer and &errno can be pure/const and
1816 * thereby hoistable. */
1817
1818 void __dls2b(size_t *sp, size_t *auxv)
1819 {
1820 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1821 * use during dynamic linking. If possible it will also serve as the
1822 * thread pointer at runtime. */
1823 search_vec(auxv, &__hwcap, AT_HWCAP);
1824 libc.auxv = auxv;
1825 libc.tls_size = sizeof builtin_tls;
1826 libc.tls_align = tls_align;
1827 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1828 a_crash();
1829 }
1830
1831 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1832 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp, auxv);
1833 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp, auxv);
1834 }
1835
1836 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1837 * fully functional. Its job is to load (if not already loaded) and
1838 * process dependencies and relocations for the main application and
1839 * transfer control to its entry point. */
1840
1841 void __dls3(size_t *sp, size_t *auxv)
1842 {
1843 static struct dso app, vdso;
1844 size_t aux[AUX_CNT];
1845 size_t i;
1846 char *env_preload=0;
1847 char *replace_argv0=0;
1848 size_t vdso_base;
1849 int argc = *sp;
1850 char **argv = (void *)(sp+1);
1851 char **argv_orig = argv;
1852 char **envp = argv+argc+1;
1853
1854 /* Find aux vector just past environ[] and use it to initialize
1855 * global data that may be needed before we can make syscalls. */
1856 __environ = envp;
1857 decode_vec(auxv, aux, AUX_CNT);
1858 search_vec(auxv, &__sysinfo, AT_SYSINFO);
1859 __pthread_self()->sysinfo = __sysinfo;
1860 libc.page_size = aux[AT_PAGESZ];
1861 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1862 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1863
1864 /* Only trust user/env if kernel says we're not suid/sgid */
1865 if (!libc.secure) {
1866 env_path = getenv("LD_LIBRARY_PATH");
1867 env_preload = getenv("LD_PRELOAD");
1868 }
1869
1870 /* Activate error handler function */
1871 error = error_impl;
1872
1873 /* If the main program was already loaded by the kernel,
1874 * AT_PHDR will point to some location other than the dynamic
1875 * linker's program headers. */
1876 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1877 size_t interp_off = 0;
1878 size_t tls_image = 0;
1879 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1880 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1881 app.phnum = aux[AT_PHNUM];
1882 app.phentsize = aux[AT_PHENT];
1883 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1884 if (phdr->p_type == PT_PHDR)
1885 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1886 else if (phdr->p_type == PT_INTERP)
1887 interp_off = (size_t)phdr->p_vaddr;
1888 else if (phdr->p_type == PT_TLS) {
1889 tls_image = phdr->p_vaddr;
1890 app.tls.len = phdr->p_filesz;
1891 app.tls.size = phdr->p_memsz;
1892 app.tls.align = phdr->p_align;
1893 }
1894 }
1895 if (DL_FDPIC) app.loadmap = app_loadmap;
1896 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1897 #ifdef __LITEOS_A__
1898 if (interp_off) ldso.name = "/lib/libc.so";
1899 #else
1900 if (interp_off) ldso.name = laddr(&app, interp_off);
1901 #endif
1902 #ifdef __LITEOS_A__
1903 if (argv[0])
1904 app.name = argv[0];
1905 else
1906 app.name = "none";
1907 #else
1908 if ((aux[0] & (1UL<<AT_EXECFN))
1909 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1910 app.name = (char *)aux[AT_EXECFN];
1911 else
1912 app.name = argv[0];
1913 #endif
1914 kernel_mapped_dso(&app);
1915 } else {
1916 int fd;
1917 char *ldname = argv[0];
1918 size_t l = strlen(ldname);
1919 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1920 argv++;
1921 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1922 char *opt = argv[0]+2;
1923 *argv++ = (void *)-1;
1924 if (!*opt) {
1925 break;
1926 } else if (!memcmp(opt, "list", 5)) {
1927 ldd_mode = 1;
1928 } else if (!memcmp(opt, "library-path", 12)) {
1929 if (opt[12]=='=') env_path = opt+13;
1930 else if (opt[12]) *argv = 0;
1931 else if (*argv) env_path = *argv++;
1932 } else if (!memcmp(opt, "preload", 7)) {
1933 if (opt[7]=='=') env_preload = opt+8;
1934 else if (opt[7]) *argv = 0;
1935 else if (*argv) env_preload = *argv++;
1936 } else if (!memcmp(opt, "argv0", 5)) {
1937 if (opt[5]=='=') replace_argv0 = opt+6;
1938 else if (opt[5]) *argv = 0;
1939 else if (*argv) replace_argv0 = *argv++;
1940 } else {
1941 argv[0] = 0;
1942 }
1943 }
1944 argv[-1] = (void *)(argc - (argv-argv_orig));
1945 if (!argv[0]) {
1946 dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1947 "Version %s\n"
1948 "Dynamic Program Loader\n"
1949 "Usage: %s [options] [--] pathname%s\n",
1950 __libc_version, ldname,
1951 ldd_mode ? "" : " [args]");
1952 _exit(1);
1953 }
1954 fd = open(argv[0], O_RDONLY);
1955 if (fd < 0) {
1956 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1957 _exit(1);
1958 }
1959 Ehdr *ehdr = map_library(fd, &app);
1960 if (!ehdr) {
1961 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1962 _exit(1);
1963 }
1964 close(fd);
1965 ldso.name = ldname;
1966 app.name = argv[0];
1967 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1968 /* Find the name that would have been used for the dynamic
1969 * linker had ldd not taken its place. */
1970 if (ldd_mode) {
1971 for (i=0; i<app.phnum; i++) {
1972 if (app.phdr[i].p_type == PT_INTERP)
1973 ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1974 }
1975 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1976 }
1977 }
1978 if (app.tls.size) {
1979 libc.tls_head = tls_tail = &app.tls;
1980 app.tls_id = tls_cnt = 1;
1981 #ifdef TLS_ABOVE_TP
1982 app.tls.offset = GAP_ABOVE_TP;
1983 app.tls.offset += (-GAP_ABOVE_TP + (uintptr_t)app.tls.image)
1984 & (app.tls.align-1);
1985 tls_offset = app.tls.offset + app.tls.size;
1986 #else
1987 tls_offset = app.tls.offset = app.tls.size
1988 + ( -((uintptr_t)app.tls.image + app.tls.size)
1989 & (app.tls.align-1) );
1990 #endif
1991 tls_align = MAXP2(tls_align, app.tls.align);
1992 }
1993 decode_dyn(&app);
1994 if (DL_FDPIC) {
1995 makefuncdescs(&app);
1996 if (!app.loadmap) {
1997 app.loadmap = (void *)&app_dummy_loadmap;
1998 app.loadmap->nsegs = 1;
1999 app.loadmap->segs[0].addr = (size_t)app.map;
2000 app.loadmap->segs[0].p_vaddr = (size_t)app.map
2001 - (size_t)app.base;
2002 app.loadmap->segs[0].p_memsz = app.map_len;
2003 }
2004 argv[-3] = (void *)app.loadmap;
2005 }
2006
2007 /* Initial dso chain consists only of the app. */
2008 head = tail = syms_tail = &app;
2009
2010 /* Donate unused parts of app and library mapping to malloc */
2011 reclaim_gaps(&app);
2012 reclaim_gaps(&ldso);
2013
2014 /* Load preload/needed libraries, add symbols to global namespace. */
2015 ldso.deps = (struct dso **)no_deps;
2016 if (env_preload) load_preload(env_preload);
2017 load_deps(&app);
2018 for (struct dso *p=head; p; p=p->next)
2019 add_syms(p);
2020
2021 /* Attach to vdso, if provided by the kernel, last so that it does
2022 * not become part of the global namespace. */
2023 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
2024 Ehdr *ehdr = (void *)vdso_base;
2025 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
2026 vdso.phnum = ehdr->e_phnum;
2027 vdso.phentsize = ehdr->e_phentsize;
2028 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
2029 if (phdr->p_type == PT_DYNAMIC)
2030 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
2031 if (phdr->p_type == PT_LOAD)
2032 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
2033 }
2034 vdso.name = "";
2035 #ifdef __LITEOS_A__
2036 vdso.shortname = "OHOS-vdso.so";
2037 #else
2038 vdso.shortname = "linux-gate.so.1";
2039 #endif
2040 vdso.relocated = 1;
2041 vdso.deps = (struct dso **)no_deps;
2042 decode_dyn(&vdso);
2043 vdso.prev = tail;
2044 tail->next = &vdso;
2045 tail = &vdso;
2046 }
2047
2048 for (i=0; app.dynv[i]; i+=2) {
2049 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
2050 app.dynv[i+1] = (size_t)&debug;
2051 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
2052 size_t *ptr = (size_t *) app.dynv[i+1];
2053 *ptr = (size_t)&debug;
2054 }
2055 if (app.dynv[i]==DT_DEBUG_INDIRECT_REL) {
2056 size_t *ptr = (size_t *)((size_t)&app.dynv[i] + app.dynv[i+1]);
2057 *ptr = (size_t)&debug;
2058 }
2059 }
2060
2061 /* This must be done before final relocations, since it calls
2062 * malloc, which may be provided by the application. Calling any
2063 * application code prior to the jump to its entry point is not
2064 * valid in our model and does not work with FDPIC, where there
2065 * are additional relocation-like fixups that only the entry point
2066 * code can see to perform. */
2067 main_ctor_queue = queue_ctors(&app);
2068
2069 /* Initial TLS must also be allocated before final relocations
2070 * might result in calloc being a call to application code. */
2071 update_tls_size();
2072 void *initial_tls = builtin_tls;
2073 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
2074 initial_tls = calloc(libc.tls_size, 1);
2075 if (!initial_tls) {
2076 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
2077 argv[0], libc.tls_size);
2078 _exit(127);
2079 }
2080 }
2081 static_tls_cnt = tls_cnt;
2082
2083 /* The main program must be relocated LAST since it may contain
2084 * copy relocations which depend on libraries' relocations. */
2085 reloc_all(app.next);
2086 reloc_all(&app);
2087
2088 /* Actual copying to new TLS needs to happen after relocations,
2089 * since the TLS images might have contained relocated addresses. */
2090 if (initial_tls != builtin_tls) {
2091 if (__init_tp(__copy_tls(initial_tls)) < 0) {
2092 a_crash();
2093 }
2094 } else {
2095 size_t tmp_tls_size = libc.tls_size;
2096 pthread_t self = __pthread_self();
2097 /* Temporarily set the tls size to the full size of
2098 * builtin_tls so that __copy_tls will use the same layout
2099 * as it did for before. Then check, just to be safe. */
2100 libc.tls_size = sizeof builtin_tls;
2101 if (__copy_tls((void*)builtin_tls) != self) a_crash();
2102 libc.tls_size = tmp_tls_size;
2103 }
2104
2105 if (ldso_fail) _exit(127);
2106 if (ldd_mode) _exit(0);
2107
2108 /* Determine if malloc was interposed by a replacement implementation
2109 * so that calloc and the memalign family can harden against the
2110 * possibility of incomplete replacement. */
2111 if (find_sym(head, "malloc", 1).dso != &ldso)
2112 __malloc_replaced = 1;
2113 if (find_sym(head, "aligned_alloc", 1).dso != &ldso)
2114 __aligned_alloc_replaced = 1;
2115
2116 /* Switch to runtime mode: any further failures in the dynamic
2117 * linker are a reportable failure rather than a fatal startup
2118 * error. */
2119 runtime = 1;
2120
2121 debug.ver = 1;
2122 debug.bp = dl_debug_state;
2123 debug.head = head;
2124 debug.base = ldso.base;
2125 debug.state = RT_CONSISTENT;
2126 _dl_debug_state();
2127
2128 if (replace_argv0) argv[0] = replace_argv0;
2129
2130 errno = 0;
2131
2132 CRTJMP((void *)aux[AT_ENTRY], argv-1);
2133 for(;;);
2134 }
2135
2136 static void prepare_lazy(struct dso *p)
2137 {
2138 size_t dyn[DYN_CNT], n, flags1=0;
2139 decode_vec(p->dynv, dyn, DYN_CNT);
2140 search_vec(p->dynv, &flags1, DT_FLAGS_1);
2141 if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
2142 return;
2143 n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
2144 if (NEED_MIPS_GOT_RELOCS) {
2145 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
2146 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
2147 n += i-j;
2148 }
2149 p->lazy = calloc(n, 3*sizeof(size_t));
2150 if (!p->lazy) {
2151 error("Error preparing lazy relocation for %s: %m", p->name);
2152 longjmp(*rtld_fail, 1);
2153 }
2154 p->lazy_next = lazy_head;
2155 lazy_head = p;
2156 }
2157
2158 void *dlopen(const char *file, int mode)
2159 {
2160 struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
2161 struct tls_module *orig_tls_tail;
2162 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
2163 size_t i;
2164 int cs;
2165 jmp_buf jb;
2166 struct dso **volatile ctor_queue = 0;
2167 #ifdef __LITEOS_A__
2168 if (mode & ~(RTLD_LAZY | RTLD_NOW | RTLD_NOLOAD | RTLD_GLOBAL | RTLD_LOCAL | RTLD_NODELETE)) {
2169 error("invalid mode parameter for dlopen().");
2170 return NULL;
2171 }
2172
2173 if ((mode & (RTLD_LAZY | RTLD_NOW)) == 0) {
2174 error("invalid mode, one of RTLD_LAZY and RTLD_NOW must be set.");
2175 return NULL;
2176 }
2177 #endif
2178 if (!file) return head;
2179
2180 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
2181 pthread_rwlock_wrlock(&lock);
2182 __inhibit_ptc();
2183
2184 debug.state = RT_ADD;
2185 _dl_debug_state();
2186
2187 p = 0;
2188 if (shutting_down) {
2189 error("Cannot dlopen while program is exiting.");
2190 goto end;
2191 }
2192 orig_tls_tail = tls_tail;
2193 orig_tls_cnt = tls_cnt;
2194 orig_tls_offset = tls_offset;
2195 orig_tls_align = tls_align;
2196 orig_lazy_head = lazy_head;
2197 orig_syms_tail = syms_tail;
2198 orig_tail = tail;
2199 noload = mode & RTLD_NOLOAD;
2200
2201 rtld_fail = &jb;
2202 if (setjmp(*rtld_fail)) {
2203 /* Clean up anything new that was (partially) loaded */
2204 revert_syms(orig_syms_tail);
2205 for (p=orig_tail->next; p; p=next) {
2206 next = p->next;
2207 while (p->td_index) {
2208 void *tmp = p->td_index->next;
2209 free(p->td_index);
2210 p->td_index = tmp;
2211 }
2212 free(p->funcdescs);
2213 if (p->rpath != p->rpath_orig)
2214 free(p->rpath);
2215 free(p->deps);
2216 unmap_library(p);
2217 free(p);
2218 }
2219 free(ctor_queue);
2220 ctor_queue = 0;
2221 if (!orig_tls_tail) libc.tls_head = 0;
2222 tls_tail = orig_tls_tail;
2223 if (tls_tail) tls_tail->next = 0;
2224 tls_cnt = orig_tls_cnt;
2225 tls_offset = orig_tls_offset;
2226 tls_align = orig_tls_align;
2227 lazy_head = orig_lazy_head;
2228 tail = orig_tail;
2229 tail->next = 0;
2230 p = 0;
2231 goto end;
2232 } else p = load_library(file, head);
2233
2234 if (!p) {
2235 error(noload ?
2236 "Library %s is not already loaded" :
2237 "Error loading shared library %s: %m",
2238 file);
2239 goto end;
2240 }
2241
2242 /* First load handling */
2243 load_deps(p);
2244 extend_bfs_deps(p);
2245 pthread_mutex_lock(&init_fini_lock);
2246 int constructed = p->constructed;
2247 pthread_mutex_unlock(&init_fini_lock);
2248 if (!constructed) ctor_queue = queue_ctors(p);
2249 if (!p->relocated && (mode & RTLD_LAZY)) {
2250 prepare_lazy(p);
2251 for (i=0; p->deps[i]; i++)
2252 if (!p->deps[i]->relocated)
2253 prepare_lazy(p->deps[i]);
2254 }
2255 if (!p->relocated || (mode & RTLD_GLOBAL)) {
2256 /* Make new symbols global, at least temporarily, so we can do
2257 * relocations. If not RTLD_GLOBAL, this is reverted below. */
2258 add_syms(p);
2259 for (i=0; p->deps[i]; i++)
2260 add_syms(p->deps[i]);
2261 }
2262 if (!p->relocated) {
2263 reloc_all(p);
2264 }
2265
2266 /* If RTLD_GLOBAL was not specified, undo any new additions
2267 * to the global symbol table. This is a nop if the library was
2268 * previously loaded and already global. */
2269 if (!(mode & RTLD_GLOBAL))
2270 revert_syms(orig_syms_tail);
2271
2272 /* Processing of deferred lazy relocations must not happen until
2273 * the new libraries are committed; otherwise we could end up with
2274 * relocations resolved to symbol definitions that get removed. */
2275 redo_lazy_relocs();
2276
2277 update_tls_size();
2278 if (tls_cnt != orig_tls_cnt)
2279 install_new_tls();
2280 orig_tail = tail;
2281 end:
2282 debug.state = RT_CONSISTENT;
2283 _dl_debug_state();
2284 __release_ptc();
2285 if (p) gencnt++;
2286 pthread_rwlock_unlock(&lock);
2287 if (ctor_queue) {
2288 do_init_fini(ctor_queue);
2289 free(ctor_queue);
2290 }
2291 pthread_setcancelstate(cs, 0);
2292 return p;
2293 }
2294
2295 hidden int __dl_invalid_handle(void *h)
2296 {
2297 struct dso *p;
2298 for (p=head; p; p=p->next) if (h==p) return 0;
2299 error("Invalid library handle %p", (void *)h);
2300 return 1;
2301 }
2302
2303 static void *addr2dso(size_t a)
2304 {
2305 struct dso *p;
2306 size_t i;
2307 if (DL_FDPIC) for (p=head; p; p=p->next) {
2308 i = count_syms(p);
2309 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
2310 return p;
2311 }
2312 for (p=head; p; p=p->next) {
2313 if (DL_FDPIC && p->loadmap) {
2314 for (i=0; i<p->loadmap->nsegs; i++) {
2315 if (a-p->loadmap->segs[i].p_vaddr
2316 < p->loadmap->segs[i].p_memsz)
2317 return p;
2318 }
2319 } else {
2320 Phdr *ph = p->phdr;
2321 size_t phcnt = p->phnum;
2322 size_t entsz = p->phentsize;
2323 size_t base = (size_t)p->base;
2324 for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
2325 if (ph->p_type != PT_LOAD) continue;
2326 if (a-base-ph->p_vaddr < ph->p_memsz)
2327 return p;
2328 }
2329 if (a-(size_t)p->map < p->map_len)
2330 return 0;
2331 }
2332 }
2333 return 0;
2334 }
2335
2336 static void *do_dlsym(struct dso *p, const char *s, void *ra)
2337 {
2338 int use_deps = 0;
2339 if (p == head || p == RTLD_DEFAULT) {
2340 p = head;
2341 } else if (p == RTLD_NEXT) {
2342 p = addr2dso((size_t)ra);
2343 if (!p) p=head;
2344 p = p->next;
2345 } else if (__dl_invalid_handle(p)) {
2346 return 0;
2347 } else
2348 use_deps = 1;
2349 struct symdef def = find_sym2(p, s, 0, use_deps);
2350 if (!def.sym) {
2351 error("Symbol not found: %s", s);
2352 return 0;
2353 }
2354 if ((def.sym->st_info&0xf) == STT_TLS)
2355 return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET});
2356 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
2357 return def.dso->funcdescs + (def.sym - def.dso->syms);
2358 return laddr(def.dso, def.sym->st_value);
2359 }
2360
2361 int dladdr(const void *addr_arg, Dl_info *info)
2362 {
2363 size_t addr = (size_t)addr_arg;
2364 struct dso *p;
2365 Sym *sym, *bestsym;
2366 uint32_t nsym;
2367 char *strings;
2368 size_t best = 0;
2369 size_t besterr = -1;
2370
2371 pthread_rwlock_rdlock(&lock);
2372 p = addr2dso(addr);
2373 pthread_rwlock_unlock(&lock);
2374
2375 if (!p) return 0;
2376
2377 sym = p->syms;
2378 strings = p->strings;
2379 nsym = count_syms(p);
2380
2381 if (DL_FDPIC) {
2382 size_t idx = (addr-(size_t)p->funcdescs)
2383 / sizeof(*p->funcdescs);
2384 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
2385 best = (size_t)(p->funcdescs + idx);
2386 bestsym = sym + idx;
2387 besterr = 0;
2388 }
2389 }
2390
2391 if (!best) for (; nsym; nsym--, sym++) {
2392 if (sym->st_value
2393 && (1<<(sym->st_info&0xf) & OK_TYPES)
2394 && (1<<(sym->st_info>>4) & OK_BINDS)) {
2395 size_t symaddr = (size_t)laddr(p, sym->st_value);
2396 if (symaddr > addr || symaddr <= best)
2397 continue;
2398 best = symaddr;
2399 bestsym = sym;
2400 besterr = addr - symaddr;
2401 if (addr == symaddr)
2402 break;
2403 }
2404 }
2405
2406 if (best && besterr > bestsym->st_size-1) {
2407 best = 0;
2408 bestsym = 0;
2409 }
2410
2411 info->dli_fname = p->name;
2412 info->dli_fbase = p->map;
2413
2414 if (!best) {
2415 info->dli_sname = 0;
2416 info->dli_saddr = 0;
2417 return 1;
2418 }
2419
2420 if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2421 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2422 info->dli_sname = strings + bestsym->st_name;
2423 info->dli_saddr = (void *)best;
2424
2425 return 1;
2426 }
2427
2428 hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2429 {
2430 void *res;
2431 pthread_rwlock_rdlock(&lock);
2432 res = do_dlsym(p, s, ra);
2433 pthread_rwlock_unlock(&lock);
2434 return res;
2435 }
2436
2437 hidden void *__dlsym_redir_time64(void *restrict p, const char *restrict s, void *restrict ra)
2438 {
2439 #if _REDIR_TIME64
2440 const char *suffix, *suffix2 = "";
2441 char redir[36];
2442
2443 /* Map the symbol name to a time64 version of itself according to the
2444 * pattern used for naming the redirected time64 symbols. */
2445 size_t l = strnlen(s, sizeof redir);
2446 if (l<4 || l==sizeof redir) goto no_redir;
2447 if (s[l-2]=='_' && s[l-1]=='r') {
2448 l -= 2;
2449 suffix2 = s+l;
2450 }
2451 if (l<4) goto no_redir;
2452 if (!strcmp(s+l-4, "time")) suffix = "64";
2453 else suffix = "_time64";
2454
2455 /* Use the presence of the remapped symbol name in libc to determine
2456 * whether it's one that requires time64 redirection; replace if so. */
2457 snprintf(redir, sizeof redir, "__%.*s%s%s", (int)l, s, suffix, suffix2);
2458 if (find_sym(&ldso, redir, 1).sym) s = redir;
2459 no_redir:
2460 #endif
2461 return __dlsym(p, s, ra);
2462 }
2463
2464 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2465 {
2466 struct dso *current;
2467 struct dl_phdr_info info;
2468 int ret = 0;
2469 for(current = head; current;) {
2470 info.dlpi_addr = (uintptr_t)current->base;
2471 info.dlpi_name = current->name;
2472 info.dlpi_phdr = current->phdr;
2473 info.dlpi_phnum = current->phnum;
2474 info.dlpi_adds = gencnt;
2475 info.dlpi_subs = 0;
2476 info.dlpi_tls_modid = current->tls_id;
2477 info.dlpi_tls_data = !current->tls_id ? 0 :
2478 __tls_get_addr((tls_mod_off_t[]){current->tls_id,0});
2479
2480 ret = (callback)(&info, sizeof (info), data);
2481
2482 if (ret != 0) break;
2483
2484 pthread_rwlock_rdlock(&lock);
2485 current = current->next;
2486 pthread_rwlock_unlock(&lock);
2487 }
2488 return ret;
2489 }
2490
2491 static void error_impl(const char *fmt, ...)
2492 {
2493 va_list ap;
2494 va_start(ap, fmt);
2495 if (!runtime) {
2496 vdprintf(2, fmt, ap);
2497 dprintf(2, "\n");
2498 ldso_fail = 1;
2499 va_end(ap);
2500 return;
2501 }
2502 __dl_vseterr(fmt, ap);
2503 va_end(ap);
2504 }
2505
2506 static void error_noop(const char *fmt, ...)
2507 {
2508 }
2509