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