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superh port
[musl.git] / src / ldso / dynlink.c
bloba1bdf0fb1b3182494abef08e4f57aa096ed323cd
1 #define _GNU_SOURCE
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <unistd.h>
6 #include <stdint.h>
7 #include <elf.h>
8 #include <sys/mman.h>
9 #include <limits.h>
10 #include <fcntl.h>
11 #include <sys/stat.h>
12 #include <errno.h>
13 #include <link.h>
14 #include <setjmp.h>
15 #include <pthread.h>
16 #include <ctype.h>
17 #include <dlfcn.h>
18 #include "pthread_impl.h"
19 #include "libc.h"
20
21 static int errflag;
22 static char errbuf[128];
23
24 #ifdef SHARED
25
26 #if ULONG_MAX == 0xffffffff
27 typedef Elf32_Ehdr Ehdr;
28 typedef Elf32_Phdr Phdr;
29 typedef Elf32_Sym Sym;
30 #define R_TYPE(x) ((x)&255)
31 #define R_SYM(x) ((x)>>8)
32 #else
33 typedef Elf64_Ehdr Ehdr;
34 typedef Elf64_Phdr Phdr;
35 typedef Elf64_Sym Sym;
36 #define R_TYPE(x) ((x)&0xffffffff)
37 #define R_SYM(x) ((x)>>32)
38 #endif
39
40 #define MAXP2(a,b) (-(-(a)&-(b)))
41 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
42
43 struct debug {
44 int ver;
45 void *head;
46 void (*bp)(void);
47 int state;
48 void *base;
49 };
50
51 struct dso {
52 unsigned char *base;
53 char *name;
54 size_t *dynv;
55 struct dso *next, *prev;
56
57 Phdr *phdr;
58 int phnum;
59 int refcnt;
60 Sym *syms;
61 uint32_t *hashtab;
62 uint32_t *ghashtab;
63 int16_t *versym;
64 char *strings;
65 unsigned char *map;
66 size_t map_len;
67 dev_t dev;
68 ino_t ino;
69 signed char global;
70 char relocated;
71 char constructed;
72 char kernel_mapped;
73 struct dso **deps, *needed_by;
74 char *rpath_orig, *rpath;
75 void *tls_image;
76 size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
77 void **new_dtv;
78 unsigned char *new_tls;
79 int new_dtv_idx, new_tls_idx;
80 struct dso *fini_next;
81 char *shortname;
82 char buf[];
83 };
84
85 struct symdef {
86 Sym *sym;
87 struct dso *dso;
88 };
89
90 #include "reloc.h"
91
92 void __init_ssp(size_t *);
93 void *__install_initial_tls(void *);
94 void __init_libc(char **, char *);
95
96 const char *__libc_get_version(void);
97
98 static struct dso *head, *tail, *ldso, *fini_head;
99 static char *env_path, *sys_path;
100 static unsigned long long gencnt;
101 static int ssp_used;
102 static int runtime;
103 static int ldd_mode;
104 static int ldso_fail;
105 static int noload;
106 static jmp_buf *rtld_fail;
107 static pthread_rwlock_t lock;
108 static struct debug debug;
109 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
110 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
111
112 struct debug *_dl_debug_addr = &debug;
113
114 #define AUX_CNT 38
115 #define DYN_CNT 34
116
117 static void decode_vec(size_t *v, size_t *a, size_t cnt)
118 {
119 memset(a, 0, cnt*sizeof(size_t));
120 for (; v[0]; v+=2) if (v[0]<cnt) {
121 a[0] |= 1ULL<<v[0];
122 a[v[0]] = v[1];
123 }
124 }
125
126 static int search_vec(size_t *v, size_t *r, size_t key)
127 {
128 for (; v[0]!=key; v+=2)
129 if (!v[0]) return 0;
130 *r = v[1];
131 return 1;
132 }
133
134 static uint32_t sysv_hash(const char *s0)
135 {
136 const unsigned char *s = (void *)s0;
137 uint_fast32_t h = 0;
138 while (*s) {
139 h = 16*h + *s++;
140 h ^= h>>24 & 0xf0;
141 }
142 return h & 0xfffffff;
143 }
144
145 static uint32_t gnu_hash(const char *s0)
146 {
147 const unsigned char *s = (void *)s0;
148 uint_fast32_t h = 5381;
149 for (; *s; s++)
150 h = h*33 + *s;
151 return h;
152 }
153
154 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
155 {
156 size_t i;
157 Sym *syms = dso->syms;
158 uint32_t *hashtab = dso->hashtab;
159 char *strings = dso->strings;
160 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
161 if ((!dso->versym || dso->versym[i] >= 0)
162 && (!strcmp(s, strings+syms[i].st_name)))
163 return syms+i;
164 }
165 return 0;
166 }
167
168 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
169 {
170 Sym *syms = dso->syms;
171 char *strings = dso->strings;
172 uint32_t *hashtab = dso->ghashtab;
173 uint32_t nbuckets = hashtab[0];
174 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
175 uint32_t h2;
176 uint32_t *hashval;
177 uint32_t i = buckets[h1 % nbuckets];
178
179 if (!i) return 0;
180
181 hashval = buckets + nbuckets + (i - hashtab[1]);
182
183 for (h1 |= 1; ; i++) {
184 h2 = *hashval++;
185 if ((!dso->versym || dso->versym[i] >= 0)
186 && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
187 return syms+i;
188 if (h2 & 1) break;
189 }
190
191 return 0;
192 }
193
194 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
195 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
196
197 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
198 {
199 uint32_t h = 0, gh = 0;
200 struct symdef def = {0};
201 if (dso->ghashtab) {
202 gh = gnu_hash(s);
203 if (gh == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
204 } else {
205 h = sysv_hash(s);
206 if (h == 0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
207 }
208 for (; dso; dso=dso->next) {
209 Sym *sym;
210 if (!dso->global) continue;
211 if (dso->ghashtab) {
212 if (!gh) gh = gnu_hash(s);
213 sym = gnu_lookup(s, gh, dso);
214 } else {
215 if (!h) h = sysv_hash(s);
216 sym = sysv_lookup(s, h, dso);
217 }
218 if (!sym) continue;
219 if (!sym->st_shndx)
220 if (need_def || (sym->st_info&0xf) == STT_TLS)
221 continue;
222 if (!sym->st_value)
223 if ((sym->st_info&0xf) != STT_TLS)
224 continue;
225 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
226 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
227
228 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
229 def.sym = sym;
230 def.dso = dso;
231 if (sym->st_info>>4 == STB_GLOBAL) break;
232 }
233 return def;
234 }
235
236 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
237 {
238 unsigned char *base = dso->base;
239 Sym *syms = dso->syms;
240 char *strings = dso->strings;
241 Sym *sym;
242 const char *name;
243 void *ctx;
244 int type;
245 int sym_index;
246 struct symdef def;
247
248 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
249 type = R_TYPE(rel[1]);
250 sym_index = R_SYM(rel[1]);
251 if (sym_index) {
252 sym = syms + sym_index;
253 name = strings + sym->st_name;
254 ctx = IS_COPY(type) ? head->next : head;
255 def = find_sym(ctx, name, IS_PLT(type));
256 if (!def.sym && (sym->st_shndx != SHN_UNDEF
257 || sym->st_info>>4 != STB_WEAK)) {
258 snprintf(errbuf, sizeof errbuf,
259 "Error relocating %s: %s: symbol not found",
260 dso->name, name);
261 if (runtime) longjmp(*rtld_fail, 1);
262 dprintf(2, "%s\n", errbuf);
263 ldso_fail = 1;
264 continue;
265 }
266 } else {
267 sym = 0;
268 def.sym = 0;
269 def.dso = 0;
270 }
271 do_single_reloc(dso, base, (void *)(base + rel[0]), type,
272 stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def,
273 def.sym?(size_t)(def.dso->base+def.sym->st_value):0);
274 }
275 }
276
277 /* A huge hack: to make up for the wastefulness of shared libraries
278 * needing at least a page of dirty memory even if they have no global
279 * data, we reclaim the gaps at the beginning and end of writable maps
280 * and "donate" them to the heap by setting up minimal malloc
281 * structures and then freeing them. */
282
283 static void reclaim(unsigned char *base, size_t start, size_t end)
284 {
285 size_t *a, *z;
286 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
287 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
288 if (start>end || end-start < 4*sizeof(size_t)) return;
289 a = (size_t *)(base + start);
290 z = (size_t *)(base + end);
291 a[-2] = 1;
292 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
293 z[1] = 1;
294 free(a);
295 }
296
297 static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phcnt)
298 {
299 for (; phcnt--; ph=(void *)((char *)ph+phent)) {
300 if (ph->p_type!=PT_LOAD) continue;
301 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
302 reclaim(base, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
303 reclaim(base, ph->p_vaddr+ph->p_memsz,
304 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
305 }
306 }
307
308 static void *map_library(int fd, struct dso *dso)
309 {
310 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
311 void *allocated_buf=0;
312 size_t phsize;
313 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
314 size_t this_min, this_max;
315 off_t off_start;
316 Ehdr *eh;
317 Phdr *ph, *ph0;
318 unsigned prot;
319 unsigned char *map=MAP_FAILED, *base;
320 size_t dyn=0;
321 size_t tls_image=0;
322 size_t i;
323
324 ssize_t l = read(fd, buf, sizeof buf);
325 eh = buf;
326 if (l<0) return 0;
327 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
328 goto noexec;
329 phsize = eh->e_phentsize * eh->e_phnum;
330 if (phsize > sizeof buf - sizeof *eh) {
331 allocated_buf = malloc(phsize);
332 if (!allocated_buf) return 0;
333 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
334 if (l < 0) goto error;
335 if (l != phsize) goto noexec;
336 ph = ph0 = allocated_buf;
337 } else if (eh->e_phoff + phsize > l) {
338 l = pread(fd, buf+1, phsize, eh->e_phoff);
339 if (l < 0) goto error;
340 if (l != phsize) goto noexec;
341 ph = ph0 = (void *)(buf + 1);
342 } else {
343 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
344 }
345 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
346 if (ph->p_type == PT_DYNAMIC)
347 dyn = ph->p_vaddr;
348 if (ph->p_type == PT_TLS) {
349 tls_image = ph->p_vaddr;
350 dso->tls_align = ph->p_align;
351 dso->tls_len = ph->p_filesz;
352 dso->tls_size = ph->p_memsz;
353 }
354 if (ph->p_type != PT_LOAD) continue;
355 if (ph->p_vaddr < addr_min) {
356 addr_min = ph->p_vaddr;
357 off_start = ph->p_offset;
358 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
359 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
360 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
361 }
362 if (ph->p_vaddr+ph->p_memsz > addr_max) {
363 addr_max = ph->p_vaddr+ph->p_memsz;
364 }
365 }
366 if (!dyn) goto noexec;
367 addr_max += PAGE_SIZE-1;
368 addr_max &= -PAGE_SIZE;
369 addr_min &= -PAGE_SIZE;
370 off_start &= -PAGE_SIZE;
371 map_len = addr_max - addr_min + off_start;
372 /* The first time, we map too much, possibly even more than
373 * the length of the file. This is okay because we will not
374 * use the invalid part; we just need to reserve the right
375 * amount of virtual address space to map over later. */
376 map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
377 if (map==MAP_FAILED) goto error;
378 /* If the loaded file is not relocatable and the requested address is
379 * not available, then the load operation must fail. */
380 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
381 errno = EBUSY;
382 goto error;
383 }
384 base = map - addr_min;
385 dso->phdr = 0;
386 dso->phnum = 0;
387 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
388 if (ph->p_type != PT_LOAD) continue;
389 /* Check if the programs headers are in this load segment, and
390 * if so, record the address for use by dl_iterate_phdr. */
391 if (!dso->phdr && eh->e_phoff >= ph->p_offset
392 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
393 dso->phdr = (void *)(base + ph->p_vaddr
394 + (eh->e_phoff-ph->p_offset));
395 dso->phnum = eh->e_phnum;
396 }
397 /* Reuse the existing mapping for the lowest-address LOAD */
398 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
399 this_min = ph->p_vaddr & -PAGE_SIZE;
400 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
401 off_start = ph->p_offset & -PAGE_SIZE;
402 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
403 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
404 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
405 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
406 goto error;
407 if (ph->p_memsz > ph->p_filesz) {
408 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
409 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
410 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
411 if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
412 goto error;
413 }
414 }
415 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
416 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
417 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
418 goto error;
419 break;
420 }
421 if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum);
422 dso->map = map;
423 dso->map_len = map_len;
424 dso->base = base;
425 dso->dynv = (void *)(base+dyn);
426 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
427 free(allocated_buf);
428 return map;
429 noexec:
430 errno = ENOEXEC;
431 error:
432 if (map!=MAP_FAILED) munmap(map, map_len);
433 free(allocated_buf);
434 return 0;
435 }
436
437 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
438 {
439 size_t l;
440 int fd;
441 for (;;) {
442 s += strspn(s, ":\n");
443 l = strcspn(s, ":\n");
444 if (l-1 >= INT_MAX) return -1;
445 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
446 continue;
447 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
448 s += l;
449 }
450 }
451
452 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
453 {
454 size_t n, l;
455 const char *s, *t, *origin;
456 char *d;
457 if (p->rpath) return 0;
458 if (!p->rpath_orig) return -1;
459 if (!strchr(p->rpath_orig, '$')) {
460 p->rpath = p->rpath_orig;
461 return 0;
462 }
463 n = 0;
464 s = p->rpath_orig;
465 while ((t=strchr(s, '$'))) {
466 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
467 return -1;
468 s = t+1;
469 n++;
470 }
471 if (n > SSIZE_MAX/PATH_MAX) return -1;
472
473 if (p->kernel_mapped) {
474 /* $ORIGIN searches cannot be performed for the main program
475 * when it is suid/sgid/AT_SECURE. This is because the
476 * pathname is under the control of the caller of execve.
477 * For libraries, however, $ORIGIN can be processed safely
478 * since the library's pathname came from a trusted source
479 * (either system paths or a call to dlopen). */
480 if (libc.secure)
481 return -1;
482 l = readlink("/proc/self/exe", buf, buf_size);
483 if (l >= buf_size)
484 return -1;
485 buf[l] = 0;
486 origin = buf;
487 } else {
488 origin = p->name;
489 }
490 t = strrchr(origin, '/');
491 l = t ? t-origin : 0;
492 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
493 if (!p->rpath) return -1;
494
495 d = p->rpath;
496 s = p->rpath_orig;
497 while ((t=strchr(s, '$'))) {
498 memcpy(d, s, t-s);
499 d += t-s;
500 memcpy(d, origin, l);
501 d += l;
502 /* It was determined previously that the '$' is followed
503 * either by "ORIGIN" or "{ORIGIN}". */
504 s = t + 7 + 2*(t[1]=='{');
505 }
506 strcpy(d, s);
507 return 0;
508 }
509
510 static void decode_dyn(struct dso *p)
511 {
512 size_t dyn[DYN_CNT] = {0};
513 decode_vec(p->dynv, dyn, DYN_CNT);
514 p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
515 p->strings = (void *)(p->base + dyn[DT_STRTAB]);
516 if (dyn[0]&(1<<DT_HASH))
517 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
518 if (dyn[0]&(1<<DT_RPATH))
519 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
520 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
521 p->ghashtab = (void *)(p->base + *dyn);
522 if (search_vec(p->dynv, dyn, DT_VERSYM))
523 p->versym = (void *)(p->base + *dyn);
524 }
525
526 static struct dso *load_library(const char *name, struct dso *needed_by)
527 {
528 char buf[2*NAME_MAX+2];
529 const char *pathname;
530 unsigned char *map;
531 struct dso *p, temp_dso = {0};
532 int fd;
533 struct stat st;
534 size_t alloc_size;
535 int n_th = 0;
536 int is_self = 0;
537
538 /* Catch and block attempts to reload the implementation itself */
539 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
540 static const char *rp, reserved[] =
541 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
542 char *z = strchr(name, '.');
543 if (z) {
544 size_t l = z-name;
545 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
546 if (*rp) {
547 if (ldd_mode) {
548 /* Track which names have been resolved
549 * and only report each one once. */
550 static unsigned reported;
551 unsigned mask = 1U<<(rp-reserved);
552 if (!(reported & mask)) {
553 reported |= mask;
554 dprintf(1, "\t%s => %s (%p)\n",
555 name, ldso->name,
556 ldso->base);
557 }
558 }
559 is_self = 1;
560 }
561 }
562 }
563 if (!strcmp(name, ldso->name)) is_self = 1;
564 if (is_self) {
565 if (!ldso->prev) {
566 tail->next = ldso;
567 ldso->prev = tail;
568 tail = ldso->next ? ldso->next : ldso;
569 }
570 return ldso;
571 }
572 if (strchr(name, '/')) {
573 pathname = name;
574 fd = open(name, O_RDONLY|O_CLOEXEC);
575 } else {
576 /* Search for the name to see if it's already loaded */
577 for (p=head->next; p; p=p->next) {
578 if (p->shortname && !strcmp(p->shortname, name)) {
579 p->refcnt++;
580 return p;
581 }
582 }
583 if (strlen(name) > NAME_MAX) return 0;
584 fd = -1;
585 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
586 for (p=needed_by; fd < 0 && p; p=p->needed_by)
587 if (!fixup_rpath(p, buf, sizeof buf))
588 fd = path_open(name, p->rpath, buf, sizeof buf);
589 if (fd < 0) {
590 if (!sys_path) {
591 char *prefix = 0;
592 size_t prefix_len;
593 if (ldso->name[0]=='/') {
594 char *s, *t, *z;
595 for (s=t=z=ldso->name; *s; s++)
596 if (*s=='/') z=t, t=s;
597 prefix_len = z-ldso->name;
598 if (prefix_len < PATH_MAX)
599 prefix = ldso->name;
600 }
601 if (!prefix) {
602 prefix = "";
603 prefix_len = 0;
604 }
605 char etc_ldso_path[prefix_len + 1
606 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
607 snprintf(etc_ldso_path, sizeof etc_ldso_path,
608 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
609 (int)prefix_len, prefix);
610 FILE *f = fopen(etc_ldso_path, "rbe");
611 if (f) {
612 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
613 free(sys_path);
614 sys_path = "";
615 }
616 fclose(f);
617 } else if (errno != ENOENT) {
618 sys_path = "";
619 }
620 }
621 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
622 fd = path_open(name, sys_path, buf, sizeof buf);
623 }
624 pathname = buf;
625 }
626 if (fd < 0) return 0;
627 if (fstat(fd, &st) < 0) {
628 close(fd);
629 return 0;
630 }
631 for (p=head->next; p; p=p->next) {
632 if (p->dev == st.st_dev && p->ino == st.st_ino) {
633 /* If this library was previously loaded with a
634 * pathname but a search found the same inode,
635 * setup its shortname so it can be found by name. */
636 if (!p->shortname && pathname != name)
637 p->shortname = strrchr(p->name, '/')+1;
638 close(fd);
639 p->refcnt++;
640 return p;
641 }
642 }
643 map = noload ? 0 : map_library(fd, &temp_dso);
644 close(fd);
645 if (!map) return 0;
646
647 /* Allocate storage for the new DSO. When there is TLS, this
648 * storage must include a reservation for all pre-existing
649 * threads to obtain copies of both the new TLS, and an
650 * extended DTV capable of storing an additional slot for
651 * the newly-loaded DSO. */
652 alloc_size = sizeof *p + strlen(pathname) + 1;
653 if (runtime && temp_dso.tls_image) {
654 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
655 + sizeof(void *) * (tls_cnt+3);
656 n_th = libc.threads_minus_1 + 1;
657 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
658 else alloc_size += n_th * per_th;
659 }
660 p = calloc(1, alloc_size);
661 if (!p) {
662 munmap(map, temp_dso.map_len);
663 return 0;
664 }
665 memcpy(p, &temp_dso, sizeof temp_dso);
666 decode_dyn(p);
667 p->dev = st.st_dev;
668 p->ino = st.st_ino;
669 p->refcnt = 1;
670 p->needed_by = needed_by;
671 p->name = p->buf;
672 strcpy(p->name, pathname);
673 /* Add a shortname only if name arg was not an explicit pathname. */
674 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
675 if (p->tls_image) {
676 if (runtime && !__pthread_self_init()) {
677 munmap(map, p->map_len);
678 free(p);
679 return 0;
680 }
681 p->tls_id = ++tls_cnt;
682 tls_align = MAXP2(tls_align, p->tls_align);
683 #ifdef TLS_ABOVE_TP
684 p->tls_offset = tls_offset + ( (tls_align-1) &
685 -(tls_offset + (uintptr_t)p->tls_image) );
686 tls_offset += p->tls_size;
687 #else
688 tls_offset += p->tls_size + p->tls_align - 1;
689 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
690 & (p->tls_align-1);
691 p->tls_offset = tls_offset;
692 #endif
693 p->new_dtv = (void *)(-sizeof(size_t) &
694 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
695 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
696 }
697
698 tail->next = p;
699 p->prev = tail;
700 tail = p;
701
702 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
703
704 return p;
705 }
706
707 static void load_deps(struct dso *p)
708 {
709 size_t i, ndeps=0;
710 struct dso ***deps = &p->deps, **tmp, *dep;
711 for (; p; p=p->next) {
712 for (i=0; p->dynv[i]; i+=2) {
713 if (p->dynv[i] != DT_NEEDED) continue;
714 dep = load_library(p->strings + p->dynv[i+1], p);
715 if (!dep) {
716 snprintf(errbuf, sizeof errbuf,
717 "Error loading shared library %s: %m (needed by %s)",
718 p->strings + p->dynv[i+1], p->name);
719 if (runtime) longjmp(*rtld_fail, 1);
720 dprintf(2, "%s\n", errbuf);
721 ldso_fail = 1;
722 continue;
723 }
724 if (runtime) {
725 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
726 if (!tmp) longjmp(*rtld_fail, 1);
727 tmp[ndeps++] = dep;
728 tmp[ndeps] = 0;
729 *deps = tmp;
730 }
731 }
732 }
733 }
734
735 static void load_preload(char *s)
736 {
737 int tmp;
738 char *z;
739 for (z=s; *z; s=z) {
740 for ( ; *s && isspace(*s); s++);
741 for (z=s; *z && !isspace(*z); z++);
742 tmp = *z;
743 *z = 0;
744 load_library(s, 0);
745 *z = tmp;
746 }
747 }
748
749 static void make_global(struct dso *p)
750 {
751 for (; p; p=p->next) p->global = 1;
752 }
753
754 static void reloc_all(struct dso *p)
755 {
756 size_t dyn[DYN_CNT] = {0};
757 for (; p; p=p->next) {
758 if (p->relocated) continue;
759 decode_vec(p->dynv, dyn, DYN_CNT);
760 #ifdef NEED_ARCH_RELOCS
761 do_arch_relocs(p, head);
762 #endif
763 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
764 2+(dyn[DT_PLTREL]==DT_RELA));
765 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
766 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
767 p->relocated = 1;
768 }
769 }
770
771 static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
772 {
773 for (; cnt--; ph = (void *)((char *)ph + stride))
774 if (ph->p_type == PT_DYNAMIC)
775 return ph->p_vaddr;
776 return 0;
777 }
778
779 static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p)
780 {
781 size_t min_addr = -1, max_addr = 0;
782 for (; cnt--; ph = (void *)((char *)ph + stride)) {
783 if (ph->p_type != PT_LOAD) continue;
784 if (ph->p_vaddr < min_addr)
785 min_addr = ph->p_vaddr;
786 if (ph->p_vaddr+ph->p_memsz > max_addr)
787 max_addr = ph->p_vaddr+ph->p_memsz;
788 }
789 min_addr &= -PAGE_SIZE;
790 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
791 p->map = p->base + min_addr;
792 p->map_len = max_addr - min_addr;
793 }
794
795 static void do_fini()
796 {
797 struct dso *p;
798 size_t dyn[DYN_CNT] = {0};
799 for (p=fini_head; p; p=p->fini_next) {
800 if (!p->constructed) continue;
801 decode_vec(p->dynv, dyn, DYN_CNT);
802 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
803 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
804 size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
805 while (n--) ((void (*)(void))*--fn)();
806 }
807 #ifndef NO_LEGACY_INITFINI
808 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
809 ((void (*)(void))(p->base + dyn[DT_FINI]))();
810 #endif
811 }
812 }
813
814 static void do_init_fini(struct dso *p)
815 {
816 size_t dyn[DYN_CNT] = {0};
817 int need_locking = libc.threads_minus_1;
818 /* Allow recursive calls that arise when a library calls
819 * dlopen from one of its constructors, but block any
820 * other threads until all ctors have finished. */
821 if (need_locking) pthread_mutex_lock(&init_fini_lock);
822 for (; p; p=p->prev) {
823 if (p->constructed) continue;
824 p->constructed = 1;
825 decode_vec(p->dynv, dyn, DYN_CNT);
826 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
827 p->fini_next = fini_head;
828 fini_head = p;
829 }
830 #ifndef NO_LEGACY_INITFINI
831 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
832 ((void (*)(void))(p->base + dyn[DT_INIT]))();
833 #endif
834 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
835 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
836 size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
837 while (n--) ((void (*)(void))*fn++)();
838 }
839 if (!need_locking && libc.threads_minus_1) {
840 need_locking = 1;
841 pthread_mutex_lock(&init_fini_lock);
842 }
843 }
844 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
845 }
846
847 void _dl_debug_state(void)
848 {
849 }
850
851 void __reset_tls()
852 {
853 pthread_t self = __pthread_self();
854 struct dso *p;
855 for (p=head; p; p=p->next) {
856 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
857 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
858 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
859 p->tls_size - p->tls_len);
860 if (p->tls_id == (size_t)self->dtv[0]) break;
861 }
862 }
863
864 void *__copy_tls(unsigned char *mem)
865 {
866 pthread_t td;
867 struct dso *p;
868
869 if (!tls_cnt) return mem;
870
871 void **dtv = (void *)mem;
872 dtv[0] = (void *)tls_cnt;
873
874 #ifdef TLS_ABOVE_TP
875 mem += sizeof(void *) * (tls_cnt+1);
876 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
877 td = (pthread_t)mem;
878 mem += sizeof(struct pthread);
879
880 for (p=head; p; p=p->next) {
881 if (!p->tls_id) continue;
882 dtv[p->tls_id] = mem + p->tls_offset;
883 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
884 }
885 #else
886 mem += libc.tls_size - sizeof(struct pthread);
887 mem -= (uintptr_t)mem & (tls_align-1);
888 td = (pthread_t)mem;
889
890 for (p=head; p; p=p->next) {
891 if (!p->tls_id) continue;
892 dtv[p->tls_id] = mem - p->tls_offset;
893 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
894 }
895 #endif
896 td->dtv = dtv;
897 return td;
898 }
899
900 void *__tls_get_addr(size_t *v)
901 {
902 pthread_t self = __pthread_self();
903 if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
904 return (char *)self->dtv[v[0]]+v[1];
905
906 /* Block signals to make accessing new TLS async-signal-safe */
907 sigset_t set;
908 pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
909 if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
910 pthread_sigmask(SIG_SETMASK, &set, 0);
911 return (char *)self->dtv[v[0]]+v[1];
912 }
913
914 /* This is safe without any locks held because, if the caller
915 * is able to request the Nth entry of the DTV, the DSO list
916 * must be valid at least that far out and it was synchronized
917 * at program startup or by an already-completed call to dlopen. */
918 struct dso *p;
919 for (p=head; p->tls_id != v[0]; p=p->next);
920
921 /* Get new DTV space from new DSO if needed */
922 if (v[0] > (size_t)self->dtv[0]) {
923 void **newdtv = p->new_dtv +
924 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
925 memcpy(newdtv, self->dtv,
926 ((size_t)self->dtv[0]+1) * sizeof(void *));
927 newdtv[0] = (void *)v[0];
928 self->dtv = newdtv;
929 }
930
931 /* Get new TLS memory from new DSO */
932 unsigned char *mem = p->new_tls +
933 (p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1);
934 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1);
935 self->dtv[v[0]] = mem;
936 memcpy(mem, p->tls_image, p->tls_len);
937 pthread_sigmask(SIG_SETMASK, &set, 0);
938 return mem + v[1];
939 }
940
941 static void update_tls_size()
942 {
943 libc.tls_size = ALIGN(
944 (1+tls_cnt) * sizeof(void *) +
945 tls_offset +
946 sizeof(struct pthread) +
947 tls_align * 2,
948 tls_align);
949 }
950
951 void *__dynlink(int argc, char **argv)
952 {
953 size_t aux[AUX_CNT] = {0};
954 size_t i;
955 Phdr *phdr;
956 Ehdr *ehdr;
957 static struct dso builtin_dsos[3];
958 struct dso *const app = builtin_dsos+0;
959 struct dso *const lib = builtin_dsos+1;
960 struct dso *const vdso = builtin_dsos+2;
961 char *env_preload=0;
962 size_t vdso_base;
963 size_t *auxv;
964 char **envp = argv+argc+1;
965
966 /* Find aux vector just past environ[] */
967 for (i=argc+1; argv[i]; i++)
968 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
969 env_path = argv[i]+16;
970 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
971 env_preload = argv[i]+11;
972 auxv = (void *)(argv+i+1);
973
974 decode_vec(auxv, aux, AUX_CNT);
975
976 /* Only trust user/env if kernel says we're not suid/sgid */
977 if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
978 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
979 env_path = 0;
980 env_preload = 0;
981 libc.secure = 1;
982 }
983 libc.page_size = aux[AT_PAGESZ];
984
985 /* If the dynamic linker was invoked as a program itself, AT_BASE
986 * will not be set. In that case, we assume the base address is
987 * the start of the page containing the PHDRs; I don't know any
988 * better approach... */
989 if (!aux[AT_BASE]) {
990 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
991 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
992 }
993
994 /* The dynamic linker load address is passed by the kernel
995 * in the AUX vector, so this is easy. */
996 lib->base = (void *)aux[AT_BASE];
997 lib->name = lib->shortname = "libc.so";
998 lib->global = 1;
999 lib->kernel_mapped = 1;
1000 ehdr = (void *)lib->base;
1001 lib->phnum = ehdr->e_phnum;
1002 lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
1003 find_map_range(lib->phdr, ehdr->e_phnum, ehdr->e_phentsize, lib);
1004 lib->dynv = (void *)(lib->base + find_dyn(lib->phdr,
1005 ehdr->e_phnum, ehdr->e_phentsize));
1006 decode_dyn(lib);
1007
1008 if (aux[AT_PHDR]) {
1009 size_t interp_off = 0;
1010 size_t tls_image = 0;
1011 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1012 app->phdr = phdr = (void *)aux[AT_PHDR];
1013 app->phnum = aux[AT_PHNUM];
1014 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1015 if (phdr->p_type == PT_PHDR)
1016 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1017 else if (phdr->p_type == PT_INTERP)
1018 interp_off = (size_t)phdr->p_vaddr;
1019 else if (phdr->p_type == PT_TLS) {
1020 tls_image = phdr->p_vaddr;
1021 app->tls_len = phdr->p_filesz;
1022 app->tls_size = phdr->p_memsz;
1023 app->tls_align = phdr->p_align;
1024 }
1025 }
1026 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
1027 if (interp_off) lib->name = (char *)app->base + interp_off;
1028 if ((aux[0] & (1UL<<AT_EXECFN))
1029 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1030 app->name = (char *)aux[AT_EXECFN];
1031 else
1032 app->name = argv[0];
1033 app->kernel_mapped = 1;
1034 app->dynv = (void *)(app->base + find_dyn(
1035 (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
1036 find_map_range((void *)aux[AT_PHDR],
1037 aux[AT_PHNUM], aux[AT_PHENT], app);
1038 } else {
1039 int fd;
1040 char *ldname = argv[0];
1041 size_t l = strlen(ldname);
1042 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1043 *argv++ = (void *)-1;
1044 if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
1045 if (!argv[0]) {
1046 dprintf(2, "musl libc\n"
1047 "Version %s\n"
1048 "Dynamic Program Loader\n"
1049 "Usage: %s [--] pathname%s\n",
1050 __libc_get_version(), ldname,
1051 ldd_mode ? "" : " [args]");
1052 _exit(1);
1053 }
1054 fd = open(argv[0], O_RDONLY);
1055 if (fd < 0) {
1056 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1057 _exit(1);
1058 }
1059 runtime = 1;
1060 ehdr = (void *)map_library(fd, app);
1061 if (!ehdr) {
1062 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1063 _exit(1);
1064 }
1065 runtime = 0;
1066 close(fd);
1067 lib->name = ldname;
1068 app->name = argv[0];
1069 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
1070 /* Find the name that would have been used for the dynamic
1071 * linker had ldd not taken its place. */
1072 if (ldd_mode) {
1073 for (i=0; i<app->phnum; i++) {
1074 if (app->phdr[i].p_type == PT_INTERP)
1075 lib->name = (void *)(app->base
1076 + app->phdr[i].p_vaddr);
1077 }
1078 dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
1079 }
1080 }
1081 if (app->tls_size) {
1082 app->tls_id = tls_cnt = 1;
1083 #ifdef TLS_ABOVE_TP
1084 app->tls_offset = 0;
1085 tls_offset = app->tls_size
1086 + ( -((uintptr_t)app->tls_image + app->tls_size)
1087 & (app->tls_align-1) );
1088 #else
1089 tls_offset = app->tls_offset = app->tls_size
1090 + ( -((uintptr_t)app->tls_image + app->tls_size)
1091 & (app->tls_align-1) );
1092 #endif
1093 tls_align = MAXP2(tls_align, app->tls_align);
1094 }
1095 app->global = 1;
1096 decode_dyn(app);
1097
1098 /* Attach to vdso, if provided by the kernel */
1099 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1100 ehdr = (void *)vdso_base;
1101 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1102 vdso->phnum = ehdr->e_phnum;
1103 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1104 if (phdr->p_type == PT_DYNAMIC)
1105 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1106 if (phdr->p_type == PT_LOAD)
1107 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1108 }
1109 vdso->name = "";
1110 vdso->shortname = "linux-gate.so.1";
1111 vdso->global = 1;
1112 decode_dyn(vdso);
1113 vdso->prev = lib;
1114 lib->next = vdso;
1115 }
1116
1117 /* Initial dso chain consists only of the app. We temporarily
1118 * append the dynamic linker/libc so we can relocate it, then
1119 * restore the initial chain in preparation for loading third
1120 * party libraries (preload/needed). */
1121 head = tail = app;
1122 ldso = lib;
1123 app->next = lib;
1124 reloc_all(lib);
1125 app->next = 0;
1126
1127 /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1128
1129 /* Donate unused parts of app and library mapping to malloc */
1130 reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
1131 ehdr = (void *)lib->base;
1132 reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
1133 ehdr->e_phentsize, ehdr->e_phnum);
1134
1135 /* Load preload/needed libraries, add their symbols to the global
1136 * namespace, and perform all remaining relocations. The main
1137 * program must be relocated LAST since it may contain copy
1138 * relocations which depend on libraries' relocations. */
1139 if (env_preload) load_preload(env_preload);
1140 load_deps(app);
1141 make_global(app);
1142
1143 reloc_all(app->next);
1144 reloc_all(app);
1145
1146 update_tls_size();
1147 if (tls_cnt) {
1148 void *mem = mmap(0, libc.tls_size, PROT_READ|PROT_WRITE,
1149 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1150 if (mem==MAP_FAILED ||
1151 !__install_initial_tls(__copy_tls(mem))) {
1152 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1153 argv[0], libc.tls_size);
1154 _exit(127);
1155 }
1156 }
1157
1158 if (ldso_fail) _exit(127);
1159 if (ldd_mode) _exit(0);
1160
1161 /* Switch to runtime mode: any further failures in the dynamic
1162 * linker are a reportable failure rather than a fatal startup
1163 * error. If the dynamic loader (dlopen) will not be used, free
1164 * all memory used by the dynamic linker. */
1165 runtime = 1;
1166
1167 #ifndef DYNAMIC_IS_RO
1168 for (i=0; app->dynv[i]; i+=2)
1169 if (app->dynv[i]==DT_DEBUG)
1170 app->dynv[i+1] = (size_t)&debug;
1171 #endif
1172 debug.ver = 1;
1173 debug.bp = _dl_debug_state;
1174 debug.head = head;
1175 debug.base = lib->base;
1176 debug.state = 0;
1177 _dl_debug_state();
1178
1179 if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]);
1180 __init_libc(envp, argv[0]);
1181 atexit(do_fini);
1182 errno = 0;
1183 do_init_fini(tail);
1184
1185 return (void *)aux[AT_ENTRY];
1186 }
1187
1188 void *dlopen(const char *file, int mode)
1189 {
1190 struct dso *volatile p, *orig_tail, *next;
1191 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1192 size_t i;
1193 int cs;
1194 jmp_buf jb;
1195
1196 if (!file) return head;
1197
1198 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1199 pthread_rwlock_wrlock(&lock);
1200 __inhibit_ptc();
1201
1202 p = 0;
1203 orig_tls_cnt = tls_cnt;
1204 orig_tls_offset = tls_offset;
1205 orig_tls_align = tls_align;
1206 orig_tail = tail;
1207 noload = mode & RTLD_NOLOAD;
1208
1209 rtld_fail = &jb;
1210 if (setjmp(*rtld_fail)) {
1211 /* Clean up anything new that was (partially) loaded */
1212 if (p && p->deps) for (i=0; p->deps[i]; i++)
1213 if (p->deps[i]->global < 0)
1214 p->deps[i]->global = 0;
1215 for (p=orig_tail->next; p; p=next) {
1216 next = p->next;
1217 munmap(p->map, p->map_len);
1218 free(p->deps);
1219 free(p);
1220 }
1221 tls_cnt = orig_tls_cnt;
1222 tls_offset = orig_tls_offset;
1223 tls_align = orig_tls_align;
1224 tail = orig_tail;
1225 tail->next = 0;
1226 p = 0;
1227 errflag = 1;
1228 goto end;
1229 } else p = load_library(file, head);
1230
1231 if (!p) {
1232 snprintf(errbuf, sizeof errbuf, noload ?
1233 "Library %s is not already loaded" :
1234 "Error loading shared library %s: %m",
1235 file);
1236 errflag = 1;
1237 goto end;
1238 }
1239
1240 /* First load handling */
1241 if (!p->deps) {
1242 load_deps(p);
1243 if (p->deps) for (i=0; p->deps[i]; i++)
1244 if (!p->deps[i]->global)
1245 p->deps[i]->global = -1;
1246 if (!p->global) p->global = -1;
1247 reloc_all(p);
1248 if (p->deps) for (i=0; p->deps[i]; i++)
1249 if (p->deps[i]->global < 0)
1250 p->deps[i]->global = 0;
1251 if (p->global < 0) p->global = 0;
1252 }
1253
1254 if (mode & RTLD_GLOBAL) {
1255 if (p->deps) for (i=0; p->deps[i]; i++)
1256 p->deps[i]->global = 1;
1257 p->global = 1;
1258 }
1259
1260 update_tls_size();
1261
1262 if (ssp_used) __init_ssp(libc.auxv);
1263
1264 _dl_debug_state();
1265 orig_tail = tail;
1266 end:
1267 __release_ptc();
1268 if (p) gencnt++;
1269 pthread_rwlock_unlock(&lock);
1270 if (p) do_init_fini(orig_tail);
1271 pthread_setcancelstate(cs, 0);
1272 return p;
1273 }
1274
1275 static int invalid_dso_handle(void *h)
1276 {
1277 struct dso *p;
1278 for (p=head; p; p=p->next) if (h==p) return 0;
1279 snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1280 errflag = 1;
1281 return 1;
1282 }
1283
1284 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1285 {
1286 size_t i;
1287 uint32_t h = 0, gh = 0;
1288 Sym *sym;
1289 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1290 if (p == RTLD_DEFAULT) {
1291 p = head;
1292 } else if (p == RTLD_NEXT) {
1293 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1294 if (!p) p=head;
1295 p = p->next;
1296 }
1297 struct symdef def = find_sym(p, s, 0);
1298 if (!def.sym) goto failed;
1299 if ((def.sym->st_info&0xf) == STT_TLS)
1300 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1301 return def.dso->base + def.sym->st_value;
1302 }
1303 if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1304 return 0;
1305 if (p->ghashtab) {
1306 gh = gnu_hash(s);
1307 sym = gnu_lookup(s, gh, p);
1308 } else {
1309 h = sysv_hash(s);
1310 sym = sysv_lookup(s, h, p);
1311 }
1312 if (sym && (sym->st_info&0xf) == STT_TLS)
1313 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1314 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1315 return p->base + sym->st_value;
1316 if (p->deps) for (i=0; p->deps[i]; i++) {
1317 if (p->deps[i]->ghashtab) {
1318 if (!gh) gh = gnu_hash(s);
1319 sym = gnu_lookup(s, gh, p->deps[i]);
1320 } else {
1321 if (!h) h = sysv_hash(s);
1322 sym = sysv_lookup(s, h, p->deps[i]);
1323 }
1324 if (sym && (sym->st_info&0xf) == STT_TLS)
1325 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1326 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1327 return p->deps[i]->base + sym->st_value;
1328 }
1329 failed:
1330 errflag = 1;
1331 snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1332 return 0;
1333 }
1334
1335 int __dladdr(const void *addr, Dl_info *info)
1336 {
1337 struct dso *p;
1338 Sym *sym;
1339 uint32_t nsym;
1340 char *strings;
1341 size_t i;
1342 void *best = 0;
1343 char *bestname;
1344
1345 pthread_rwlock_rdlock(&lock);
1346 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1347 pthread_rwlock_unlock(&lock);
1348
1349 if (!p) return 0;
1350
1351 sym = p->syms;
1352 strings = p->strings;
1353 if (p->hashtab) {
1354 nsym = p->hashtab[1];
1355 } else {
1356 uint32_t *buckets;
1357 uint32_t *hashval;
1358 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1359 sym += p->ghashtab[1];
1360 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1361 if (buckets[i] > nsym)
1362 nsym = buckets[i];
1363 }
1364 if (nsym) {
1365 nsym -= p->ghashtab[1];
1366 hashval = buckets + p->ghashtab[0] + nsym;
1367 do nsym++;
1368 while (!(*hashval++ & 1));
1369 }
1370 }
1371
1372 for (; nsym; nsym--, sym++) {
1373 if (sym->st_value
1374 && (1<<(sym->st_info&0xf) & OK_TYPES)
1375 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1376 void *symaddr = p->base + sym->st_value;
1377 if (symaddr > addr || symaddr < best)
1378 continue;
1379 best = symaddr;
1380 bestname = strings + sym->st_name;
1381 if (addr == symaddr)
1382 break;
1383 }
1384 }
1385
1386 if (!best) return 0;
1387
1388 info->dli_fname = p->name;
1389 info->dli_fbase = p->base;
1390 info->dli_sname = bestname;
1391 info->dli_saddr = best;
1392
1393 return 1;
1394 }
1395
1396 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1397 {
1398 void *res;
1399 pthread_rwlock_rdlock(&lock);
1400 res = do_dlsym(p, s, ra);
1401 pthread_rwlock_unlock(&lock);
1402 return res;
1403 }
1404
1405 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1406 {
1407 struct dso *current;
1408 struct dl_phdr_info info;
1409 int ret = 0;
1410 for(current = head; current;) {
1411 info.dlpi_addr = (uintptr_t)current->base;
1412 info.dlpi_name = current->name;
1413 info.dlpi_phdr = current->phdr;
1414 info.dlpi_phnum = current->phnum;
1415 info.dlpi_adds = gencnt;
1416 info.dlpi_subs = 0;
1417 info.dlpi_tls_modid = current->tls_id;
1418 info.dlpi_tls_data = current->tls_image;
1419
1420 ret = (callback)(&info, sizeof (info), data);
1421
1422 if (ret != 0) break;
1423
1424 pthread_rwlock_rdlock(&lock);
1425 current = current->next;
1426 pthread_rwlock_unlock(&lock);
1427 }
1428 return ret;
1429 }
1430 #else
1431 static int invalid_dso_handle(void *h)
1432 {
1433 snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1434 errflag = 1;
1435 return 1;
1436 }
1437 void *dlopen(const char *file, int mode)
1438 {
1439 return 0;
1440 }
1441 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1442 {
1443 return 0;
1444 }
1445 int __dladdr (const void *addr, Dl_info *info)
1446 {
1447 return 0;
1448 }
1449 #endif
1450
1451 int __dlinfo(void *dso, int req, void *res)
1452 {
1453 if (invalid_dso_handle(dso)) return -1;
1454 if (req != RTLD_DI_LINKMAP) {
1455 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1456 errflag = 1;
1457 return -1;
1458 }
1459 *(struct link_map **)res = dso;
1460 return 0;
1461 }
1462
1463 char *dlerror()
1464 {
1465 if (!errflag) return 0;
1466 errflag = 0;
1467 return errbuf;
1468 }
1469
1470 int dlclose(void *p)
1471 {
1472 return invalid_dso_handle(p);
1473 }
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