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add general fdpic support in dynamic linker and arch support for sh
[musl.git] / src / ldso / dynlink.c
blob4903dbd2da3c3131fd90411e6f628a4c319a7cc2
1 #define _GNU_SOURCE
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <stdarg.h>
5 #include <stddef.h>
6 #include <string.h>
7 #include <unistd.h>
8 #include <stdint.h>
9 #include <elf.h>
10 #include <sys/mman.h>
11 #include <limits.h>
12 #include <fcntl.h>
13 #include <sys/stat.h>
14 #include <errno.h>
15 #include <link.h>
16 #include <setjmp.h>
17 #include <pthread.h>
18 #include <ctype.h>
19 #include <dlfcn.h>
20 #include "pthread_impl.h"
21 #include "libc.h"
22 #include "dynlink.h"
23
24 static void error(const char *, ...);
25
26 #ifdef SHARED
27
28 #define MAXP2(a,b) (-(-(a)&-(b)))
29 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
30
31 struct debug {
32 int ver;
33 void *head;
34 void (*bp)(void);
35 int state;
36 void *base;
37 };
38
39 struct td_index {
40 size_t args[2];
41 struct td_index *next;
42 };
43
44 struct dso {
45 #if DL_FDPIC
46 struct fdpic_loadmap *loadmap;
47 #else
48 unsigned char *base;
49 #endif
50 char *name;
51 size_t *dynv;
52 struct dso *next, *prev;
53
54 Phdr *phdr;
55 int phnum;
56 size_t phentsize;
57 int refcnt;
58 Sym *syms;
59 uint32_t *hashtab;
60 uint32_t *ghashtab;
61 int16_t *versym;
62 char *strings;
63 unsigned char *map;
64 size_t map_len;
65 dev_t dev;
66 ino_t ino;
67 signed char global;
68 char relocated;
69 char constructed;
70 char kernel_mapped;
71 struct dso **deps, *needed_by;
72 char *rpath_orig, *rpath;
73 void *tls_image;
74 size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
75 size_t relro_start, relro_end;
76 void **new_dtv;
77 unsigned char *new_tls;
78 volatile int new_dtv_idx, new_tls_idx;
79 struct td_index *td_index;
80 struct dso *fini_next;
81 char *shortname;
82 #if DL_FDPIC
83 unsigned char *base;
84 #else
85 struct fdpic_loadmap *loadmap;
86 #endif
87 struct funcdesc {
88 void *addr;
89 size_t *got;
90 } *funcdescs;
91 size_t *got;
92 char buf[];
93 };
94
95 struct symdef {
96 Sym *sym;
97 struct dso *dso;
98 };
99
100 int __init_tp(void *);
101 void __init_libc(char **, char *);
102
103 const char *__libc_get_version(void);
104
105 static struct builtin_tls {
106 char c;
107 struct pthread pt;
108 void *space[16];
109 } builtin_tls[1];
110 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
111
112 #define ADDEND_LIMIT 4096
113 static size_t *saved_addends, *apply_addends_to;
114
115 static struct dso ldso;
116 static struct dso *head, *tail, *fini_head;
117 static char *env_path, *sys_path;
118 static unsigned long long gencnt;
119 static int runtime;
120 static int ldd_mode;
121 static int ldso_fail;
122 static int noload;
123 static jmp_buf *rtld_fail;
124 static pthread_rwlock_t lock;
125 static struct debug debug;
126 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
127 static size_t static_tls_cnt;
128 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
129 static struct fdpic_loadmap *app_loadmap;
130 static struct fdpic_dummy_loadmap app_dummy_loadmap;
131
132 struct debug *_dl_debug_addr = &debug;
133
134 static int dl_strcmp(const char *l, const char *r)
135 {
136 for (; *l==*r && *l; l++, r++);
137 return *(unsigned char *)l - *(unsigned char *)r;
138 }
139 #define strcmp(l,r) dl_strcmp(l,r)
140
141 /* Compute load address for a virtual address in a given dso. */
142 #ifdef DL_FDPIC
143 static void *laddr(const struct dso *p, size_t v)
144 {
145 size_t j=0;
146 if (!p->loadmap) return p->base + v;
147 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
148 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
149 }
150 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
151 laddr(p, v), (p)->got })
152 #else
153 #define laddr(p, v) (void *)((p)->base + (v))
154 #define fpaddr(p, v) ((void (*)())laddr(p, v))
155 #endif
156
157 static void decode_vec(size_t *v, size_t *a, size_t cnt)
158 {
159 size_t i;
160 for (i=0; i<cnt; i++) a[i] = 0;
161 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
162 a[0] |= 1UL<<v[0];
163 a[v[0]] = v[1];
164 }
165 }
166
167 static int search_vec(size_t *v, size_t *r, size_t key)
168 {
169 for (; v[0]!=key; v+=2)
170 if (!v[0]) return 0;
171 *r = v[1];
172 return 1;
173 }
174
175 static uint32_t sysv_hash(const char *s0)
176 {
177 const unsigned char *s = (void *)s0;
178 uint_fast32_t h = 0;
179 while (*s) {
180 h = 16*h + *s++;
181 h ^= h>>24 & 0xf0;
182 }
183 return h & 0xfffffff;
184 }
185
186 static uint32_t gnu_hash(const char *s0)
187 {
188 const unsigned char *s = (void *)s0;
189 uint_fast32_t h = 5381;
190 for (; *s; s++)
191 h += h*32 + *s;
192 return h;
193 }
194
195 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
196 {
197 size_t i;
198 Sym *syms = dso->syms;
199 uint32_t *hashtab = dso->hashtab;
200 char *strings = dso->strings;
201 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
202 if ((!dso->versym || dso->versym[i] >= 0)
203 && (!strcmp(s, strings+syms[i].st_name)))
204 return syms+i;
205 }
206 return 0;
207 }
208
209 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
210 {
211 uint32_t nbuckets = hashtab[0];
212 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
213 uint32_t i = buckets[h1 % nbuckets];
214
215 if (!i) return 0;
216
217 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
218
219 for (h1 |= 1; ; i++) {
220 uint32_t h2 = *hashval++;
221 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
222 && !strcmp(s, dso->strings + dso->syms[i].st_name))
223 return dso->syms+i;
224 if (h2 & 1) break;
225 }
226
227 return 0;
228 }
229
230 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
231 {
232 const size_t *bloomwords = (const void *)(hashtab+4);
233 size_t f = bloomwords[fofs & (hashtab[2]-1)];
234 if (!(f & fmask)) return 0;
235
236 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
237 if (!(f & 1)) return 0;
238
239 return gnu_lookup(h1, hashtab, dso, s);
240 }
241
242 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
243 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
244
245 #ifndef ARCH_SYM_REJECT_UND
246 #define ARCH_SYM_REJECT_UND(s) 0
247 #endif
248
249 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
250 {
251 uint32_t h = 0, gh, gho, *ght;
252 size_t ghm = 0;
253 struct symdef def = {0};
254 for (; dso; dso=dso->next) {
255 Sym *sym;
256 if (!dso->global) continue;
257 if ((ght = dso->ghashtab)) {
258 if (!ghm) {
259 gh = gnu_hash(s);
260 int maskbits = 8 * sizeof ghm;
261 gho = gh / maskbits;
262 ghm = 1ul << gh % maskbits;
263 }
264 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
265 } else {
266 if (!h) h = sysv_hash(s);
267 sym = sysv_lookup(s, h, dso);
268 }
269 if (!sym) continue;
270 if (!sym->st_shndx)
271 if (need_def || (sym->st_info&0xf) == STT_TLS
272 || ARCH_SYM_REJECT_UND(sym))
273 continue;
274 if (!sym->st_value)
275 if ((sym->st_info&0xf) != STT_TLS)
276 continue;
277 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
278 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
279
280 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
281 def.sym = sym;
282 def.dso = dso;
283 if (sym->st_info>>4 == STB_GLOBAL) break;
284 }
285 return def;
286 }
287
288 __attribute__((__visibility__("hidden")))
289 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
290
291 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
292 {
293 unsigned char *base = dso->base;
294 Sym *syms = dso->syms;
295 char *strings = dso->strings;
296 Sym *sym;
297 const char *name;
298 void *ctx;
299 int type;
300 int sym_index;
301 struct symdef def;
302 size_t *reloc_addr;
303 size_t sym_val;
304 size_t tls_val;
305 size_t addend;
306 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
307
308 if (dso == &ldso) {
309 /* Only ldso's REL table needs addend saving/reuse. */
310 if (rel == apply_addends_to)
311 reuse_addends = 1;
312 skip_relative = 1;
313 }
314
315 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
316 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
317 type = R_TYPE(rel[1]);
318 if (type == REL_NONE) continue;
319 sym_index = R_SYM(rel[1]);
320 reloc_addr = laddr(dso, rel[0]);
321 if (sym_index) {
322 sym = syms + sym_index;
323 name = strings + sym->st_name;
324 ctx = type==REL_COPY ? head->next : head;
325 def = (sym->st_info&0xf) == STT_SECTION
326 ? (struct symdef){ .dso = dso, .sym = sym }
327 : find_sym(ctx, name, type==REL_PLT);
328 if (!def.sym && (sym->st_shndx != SHN_UNDEF
329 || sym->st_info>>4 != STB_WEAK)) {
330 error("Error relocating %s: %s: symbol not found",
331 dso->name, name);
332 if (runtime) longjmp(*rtld_fail, 1);
333 continue;
334 }
335 } else {
336 sym = 0;
337 def.sym = 0;
338 def.dso = dso;
339 }
340
341 if (stride > 2) {
342 addend = rel[2];
343 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
344 addend = 0;
345 } else if (reuse_addends) {
346 /* Save original addend in stage 2 where the dso
347 * chain consists of just ldso; otherwise read back
348 * saved addend since the inline one was clobbered. */
349 if (head==&ldso)
350 saved_addends[save_slot] = *reloc_addr;
351 addend = saved_addends[save_slot++];
352 } else {
353 addend = *reloc_addr;
354 }
355
356 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
357 tls_val = def.sym ? def.sym->st_value : 0;
358
359 switch(type) {
360 case REL_NONE:
361 break;
362 case REL_OFFSET:
363 addend -= (size_t)reloc_addr;
364 case REL_SYMBOLIC:
365 case REL_GOT:
366 case REL_PLT:
367 *reloc_addr = sym_val + addend;
368 break;
369 case REL_RELATIVE:
370 *reloc_addr = (size_t)base + addend;
371 break;
372 case REL_SYM_OR_REL:
373 if (sym) *reloc_addr = sym_val + addend;
374 else *reloc_addr = (size_t)base + addend;
375 break;
376 case REL_COPY:
377 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
378 break;
379 case REL_OFFSET32:
380 *(uint32_t *)reloc_addr = sym_val + addend
381 - (size_t)reloc_addr;
382 break;
383 case REL_FUNCDESC:
384 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
385 + (def.sym - def.dso->syms)) : 0;
386 break;
387 case REL_FUNCDESC_VAL:
388 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
389 else *reloc_addr = sym_val;
390 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
391 break;
392 case REL_DTPMOD:
393 *reloc_addr = def.dso->tls_id;
394 break;
395 case REL_DTPOFF:
396 *reloc_addr = tls_val + addend - DTP_OFFSET;
397 break;
398 #ifdef TLS_ABOVE_TP
399 case REL_TPOFF:
400 *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
401 break;
402 #else
403 case REL_TPOFF:
404 *reloc_addr = tls_val - def.dso->tls_offset + addend;
405 break;
406 case REL_TPOFF_NEG:
407 *reloc_addr = def.dso->tls_offset - tls_val + addend;
408 break;
409 #endif
410 case REL_TLSDESC:
411 if (stride<3) addend = reloc_addr[1];
412 if (runtime && def.dso->tls_id >= static_tls_cnt) {
413 struct td_index *new = malloc(sizeof *new);
414 if (!new) {
415 error(
416 "Error relocating %s: cannot allocate TLSDESC for %s",
417 dso->name, sym ? name : "(local)" );
418 longjmp(*rtld_fail, 1);
419 }
420 new->next = dso->td_index;
421 dso->td_index = new;
422 new->args[0] = def.dso->tls_id;
423 new->args[1] = tls_val + addend;
424 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
425 reloc_addr[1] = (size_t)new;
426 } else {
427 reloc_addr[0] = (size_t)__tlsdesc_static;
428 #ifdef TLS_ABOVE_TP
429 reloc_addr[1] = tls_val + def.dso->tls_offset
430 + TPOFF_K + addend;
431 #else
432 reloc_addr[1] = tls_val - def.dso->tls_offset
433 + addend;
434 #endif
435 }
436 break;
437 default:
438 error("Error relocating %s: unsupported relocation type %d",
439 dso->name, type);
440 if (runtime) longjmp(*rtld_fail, 1);
441 continue;
442 }
443 }
444 }
445
446 /* A huge hack: to make up for the wastefulness of shared libraries
447 * needing at least a page of dirty memory even if they have no global
448 * data, we reclaim the gaps at the beginning and end of writable maps
449 * and "donate" them to the heap by setting up minimal malloc
450 * structures and then freeing them. */
451
452 static void reclaim(struct dso *dso, size_t start, size_t end)
453 {
454 size_t *a, *z;
455 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
456 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
457 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
458 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
459 if (start>end || end-start < 4*sizeof(size_t)) return;
460 a = laddr(dso, start);
461 z = laddr(dso, end);
462 a[-2] = 1;
463 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
464 z[1] = 1;
465 free(a);
466 }
467
468 static void reclaim_gaps(struct dso *dso)
469 {
470 Phdr *ph = dso->phdr;
471 size_t phcnt = dso->phnum;
472
473 if (DL_FDPIC) return; // FIXME
474 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
475 if (ph->p_type!=PT_LOAD) continue;
476 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
477 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
478 reclaim(dso, ph->p_vaddr+ph->p_memsz,
479 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
480 }
481 }
482
483 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
484 {
485 char *q = mmap(p, n, prot, flags, fd, off);
486 if (q != MAP_FAILED || errno != EINVAL) return q;
487 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
488 if (flags & MAP_ANONYMOUS) {
489 memset(p, 0, n);
490 return p;
491 }
492 ssize_t r;
493 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
494 for (q=p; n; q+=r, off+=r, n-=r) {
495 r = read(fd, q, n);
496 if (r < 0 && errno != EINTR) return MAP_FAILED;
497 if (!r) {
498 memset(q, 0, n);
499 break;
500 }
501 }
502 return p;
503 }
504
505 static void *map_library(int fd, struct dso *dso)
506 {
507 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
508 void *allocated_buf=0;
509 size_t phsize;
510 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
511 size_t this_min, this_max;
512 off_t off_start;
513 Ehdr *eh;
514 Phdr *ph, *ph0;
515 unsigned prot;
516 unsigned char *map=MAP_FAILED, *base;
517 size_t dyn=0;
518 size_t tls_image=0;
519 size_t i;
520
521 ssize_t l = read(fd, buf, sizeof buf);
522 eh = buf;
523 if (l<0) return 0;
524 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
525 goto noexec;
526 phsize = eh->e_phentsize * eh->e_phnum;
527 if (phsize > sizeof buf - sizeof *eh) {
528 allocated_buf = malloc(phsize);
529 if (!allocated_buf) return 0;
530 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
531 if (l < 0) goto error;
532 if (l != phsize) goto noexec;
533 ph = ph0 = allocated_buf;
534 } else if (eh->e_phoff + phsize > l) {
535 l = pread(fd, buf+1, phsize, eh->e_phoff);
536 if (l < 0) goto error;
537 if (l != phsize) goto noexec;
538 ph = ph0 = (void *)(buf + 1);
539 } else {
540 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
541 }
542 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
543 if (ph->p_type == PT_DYNAMIC) {
544 dyn = ph->p_vaddr;
545 } else if (ph->p_type == PT_TLS) {
546 tls_image = ph->p_vaddr;
547 dso->tls_align = ph->p_align;
548 dso->tls_len = ph->p_filesz;
549 dso->tls_size = ph->p_memsz;
550 } else if (ph->p_type == PT_GNU_RELRO) {
551 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
552 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
553 }
554 if (ph->p_type != PT_LOAD) continue;
555 if (ph->p_vaddr < addr_min) {
556 addr_min = ph->p_vaddr;
557 off_start = ph->p_offset;
558 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
559 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
560 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
561 }
562 if (ph->p_vaddr+ph->p_memsz > addr_max) {
563 addr_max = ph->p_vaddr+ph->p_memsz;
564 }
565 }
566 if (!dyn) goto noexec;
567 addr_max += PAGE_SIZE-1;
568 addr_max &= -PAGE_SIZE;
569 addr_min &= -PAGE_SIZE;
570 off_start &= -PAGE_SIZE;
571 map_len = addr_max - addr_min + off_start;
572 /* The first time, we map too much, possibly even more than
573 * the length of the file. This is okay because we will not
574 * use the invalid part; we just need to reserve the right
575 * amount of virtual address space to map over later. */
576 map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
577 if (map==MAP_FAILED) goto error;
578 /* If the loaded file is not relocatable and the requested address is
579 * not available, then the load operation must fail. */
580 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
581 errno = EBUSY;
582 goto error;
583 }
584 base = map - addr_min;
585 dso->phdr = 0;
586 dso->phnum = 0;
587 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
588 if (ph->p_type != PT_LOAD) continue;
589 /* Check if the programs headers are in this load segment, and
590 * if so, record the address for use by dl_iterate_phdr. */
591 if (!dso->phdr && eh->e_phoff >= ph->p_offset
592 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
593 dso->phdr = (void *)(base + ph->p_vaddr
594 + (eh->e_phoff-ph->p_offset));
595 dso->phnum = eh->e_phnum;
596 dso->phentsize = eh->e_phentsize;
597 }
598 /* Reuse the existing mapping for the lowest-address LOAD */
599 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
600 this_min = ph->p_vaddr & -PAGE_SIZE;
601 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
602 off_start = ph->p_offset & -PAGE_SIZE;
603 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
604 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
605 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
606 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
607 goto error;
608 if (ph->p_memsz > ph->p_filesz) {
609 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
610 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
611 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
612 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)
613 goto error;
614 }
615 }
616 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
617 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
618 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
619 && errno != ENOSYS)
620 goto error;
621 break;
622 }
623 dso->map = map;
624 dso->map_len = map_len;
625 dso->base = base;
626 dso->dynv = (void *)(base+dyn);
627 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
628 if (!runtime) reclaim_gaps(dso);
629 free(allocated_buf);
630 return map;
631 noexec:
632 errno = ENOEXEC;
633 error:
634 if (map!=MAP_FAILED) munmap(map, map_len);
635 free(allocated_buf);
636 return 0;
637 }
638
639 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
640 {
641 size_t l;
642 int fd;
643 for (;;) {
644 s += strspn(s, ":\n");
645 l = strcspn(s, ":\n");
646 if (l-1 >= INT_MAX) return -1;
647 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
648 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
649 switch (errno) {
650 case ENOENT:
651 case ENOTDIR:
652 case EACCES:
653 case ENAMETOOLONG:
654 break;
655 default:
656 /* Any negative value but -1 will inhibit
657 * futher path search. */
658 return -2;
659 }
660 }
661 s += l;
662 }
663 }
664
665 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
666 {
667 size_t n, l;
668 const char *s, *t, *origin;
669 char *d;
670 if (p->rpath || !p->rpath_orig) return 0;
671 if (!strchr(p->rpath_orig, '$')) {
672 p->rpath = p->rpath_orig;
673 return 0;
674 }
675 n = 0;
676 s = p->rpath_orig;
677 while ((t=strchr(s, '$'))) {
678 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
679 return 0;
680 s = t+1;
681 n++;
682 }
683 if (n > SSIZE_MAX/PATH_MAX) return 0;
684
685 if (p->kernel_mapped) {
686 /* $ORIGIN searches cannot be performed for the main program
687 * when it is suid/sgid/AT_SECURE. This is because the
688 * pathname is under the control of the caller of execve.
689 * For libraries, however, $ORIGIN can be processed safely
690 * since the library's pathname came from a trusted source
691 * (either system paths or a call to dlopen). */
692 if (libc.secure)
693 return 0;
694 l = readlink("/proc/self/exe", buf, buf_size);
695 if (l == -1) switch (errno) {
696 case ENOENT:
697 case ENOTDIR:
698 case EACCES:
699 break;
700 default:
701 return -1;
702 }
703 if (l >= buf_size)
704 return 0;
705 buf[l] = 0;
706 origin = buf;
707 } else {
708 origin = p->name;
709 }
710 t = strrchr(origin, '/');
711 l = t ? t-origin : 0;
712 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
713 if (!p->rpath) return -1;
714
715 d = p->rpath;
716 s = p->rpath_orig;
717 while ((t=strchr(s, '$'))) {
718 memcpy(d, s, t-s);
719 d += t-s;
720 memcpy(d, origin, l);
721 d += l;
722 /* It was determined previously that the '$' is followed
723 * either by "ORIGIN" or "{ORIGIN}". */
724 s = t + 7 + 2*(t[1]=='{');
725 }
726 strcpy(d, s);
727 return 0;
728 }
729
730 static void decode_dyn(struct dso *p)
731 {
732 size_t dyn[DYN_CNT];
733 decode_vec(p->dynv, dyn, DYN_CNT);
734 p->syms = laddr(p, dyn[DT_SYMTAB]);
735 p->strings = laddr(p, dyn[DT_STRTAB]);
736 if (dyn[0]&(1<<DT_HASH))
737 p->hashtab = laddr(p, dyn[DT_HASH]);
738 if (dyn[0]&(1<<DT_RPATH))
739 p->rpath_orig = p->strings + dyn[DT_RPATH];
740 if (dyn[0]&(1<<DT_RUNPATH))
741 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
742 if (dyn[0]&(1<<DT_PLTGOT))
743 p->got = laddr(p, dyn[DT_PLTGOT]);
744 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
745 p->ghashtab = laddr(p, *dyn);
746 if (search_vec(p->dynv, dyn, DT_VERSYM))
747 p->versym = laddr(p, *dyn);
748 }
749
750 static size_t count_syms(struct dso *p)
751 {
752 if (p->hashtab) return p->hashtab[1];
753
754 size_t nsym, i;
755 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
756 uint32_t *hashval;
757 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
758 if (buckets[i] > nsym)
759 nsym = buckets[i];
760 }
761 if (nsym) {
762 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
763 do nsym++;
764 while (!(*hashval++ & 1));
765 }
766 return nsym;
767 }
768
769 static void *dl_mmap(size_t n)
770 {
771 void *p;
772 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
773 #ifdef SYS_mmap2
774 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
775 #else
776 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
777 #endif
778 return p == MAP_FAILED ? 0 : p;
779 }
780
781 static void makefuncdescs(struct dso *p)
782 {
783 static int self_done;
784 size_t nsym = count_syms(p);
785 size_t i, size = nsym * sizeof(*p->funcdescs);
786
787 if (!self_done) {
788 p->funcdescs = dl_mmap(size);
789 self_done = 1;
790 } else {
791 p->funcdescs = malloc(size);
792 }
793 if (!p->funcdescs) {
794 if (!runtime) a_crash();
795 error("Error allocating function descriptors for %s", p->name);
796 longjmp(*rtld_fail, 1);
797 }
798 for (i=0; i<nsym; i++) {
799 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
800 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
801 p->funcdescs[i].got = p->got;
802 } else {
803 p->funcdescs[i].addr = 0;
804 p->funcdescs[i].got = 0;
805 }
806 }
807 }
808
809 static struct dso *load_library(const char *name, struct dso *needed_by)
810 {
811 char buf[2*NAME_MAX+2];
812 const char *pathname;
813 unsigned char *map;
814 struct dso *p, temp_dso = {0};
815 int fd;
816 struct stat st;
817 size_t alloc_size;
818 int n_th = 0;
819 int is_self = 0;
820
821 if (!*name) {
822 errno = EINVAL;
823 return 0;
824 }
825
826 /* Catch and block attempts to reload the implementation itself */
827 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
828 static const char *rp, reserved[] =
829 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
830 char *z = strchr(name, '.');
831 if (z) {
832 size_t l = z-name;
833 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
834 if (*rp) {
835 if (ldd_mode) {
836 /* Track which names have been resolved
837 * and only report each one once. */
838 static unsigned reported;
839 unsigned mask = 1U<<(rp-reserved);
840 if (!(reported & mask)) {
841 reported |= mask;
842 dprintf(1, "\t%s => %s (%p)\n",
843 name, ldso.name,
844 ldso.base);
845 }
846 }
847 is_self = 1;
848 }
849 }
850 }
851 if (!strcmp(name, ldso.name)) is_self = 1;
852 if (is_self) {
853 if (!ldso.prev) {
854 tail->next = &ldso;
855 ldso.prev = tail;
856 tail = ldso.next ? ldso.next : &ldso;
857 }
858 return &ldso;
859 }
860 if (strchr(name, '/')) {
861 pathname = name;
862 fd = open(name, O_RDONLY|O_CLOEXEC);
863 } else {
864 /* Search for the name to see if it's already loaded */
865 for (p=head->next; p; p=p->next) {
866 if (p->shortname && !strcmp(p->shortname, name)) {
867 p->refcnt++;
868 return p;
869 }
870 }
871 if (strlen(name) > NAME_MAX) return 0;
872 fd = -1;
873 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
874 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
875 if (fixup_rpath(p, buf, sizeof buf) < 0)
876 fd = -2; /* Inhibit further search. */
877 if (p->rpath)
878 fd = path_open(name, p->rpath, buf, sizeof buf);
879 }
880 if (fd == -1) {
881 if (!sys_path) {
882 char *prefix = 0;
883 size_t prefix_len;
884 if (ldso.name[0]=='/') {
885 char *s, *t, *z;
886 for (s=t=z=ldso.name; *s; s++)
887 if (*s=='/') z=t, t=s;
888 prefix_len = z-ldso.name;
889 if (prefix_len < PATH_MAX)
890 prefix = ldso.name;
891 }
892 if (!prefix) {
893 prefix = "";
894 prefix_len = 0;
895 }
896 char etc_ldso_path[prefix_len + 1
897 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
898 snprintf(etc_ldso_path, sizeof etc_ldso_path,
899 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
900 (int)prefix_len, prefix);
901 FILE *f = fopen(etc_ldso_path, "rbe");
902 if (f) {
903 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
904 free(sys_path);
905 sys_path = "";
906 }
907 fclose(f);
908 } else if (errno != ENOENT) {
909 sys_path = "";
910 }
911 }
912 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
913 fd = path_open(name, sys_path, buf, sizeof buf);
914 }
915 pathname = buf;
916 }
917 if (fd < 0) return 0;
918 if (fstat(fd, &st) < 0) {
919 close(fd);
920 return 0;
921 }
922 for (p=head->next; p; p=p->next) {
923 if (p->dev == st.st_dev && p->ino == st.st_ino) {
924 /* If this library was previously loaded with a
925 * pathname but a search found the same inode,
926 * setup its shortname so it can be found by name. */
927 if (!p->shortname && pathname != name)
928 p->shortname = strrchr(p->name, '/')+1;
929 close(fd);
930 p->refcnt++;
931 return p;
932 }
933 }
934 map = noload ? 0 : map_library(fd, &temp_dso);
935 close(fd);
936 if (!map) return 0;
937
938 /* Allocate storage for the new DSO. When there is TLS, this
939 * storage must include a reservation for all pre-existing
940 * threads to obtain copies of both the new TLS, and an
941 * extended DTV capable of storing an additional slot for
942 * the newly-loaded DSO. */
943 alloc_size = sizeof *p + strlen(pathname) + 1;
944 if (runtime && temp_dso.tls_image) {
945 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
946 + sizeof(void *) * (tls_cnt+3);
947 n_th = libc.threads_minus_1 + 1;
948 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
949 else alloc_size += n_th * per_th;
950 }
951 p = calloc(1, alloc_size);
952 if (!p) {
953 munmap(map, temp_dso.map_len);
954 return 0;
955 }
956 memcpy(p, &temp_dso, sizeof temp_dso);
957 decode_dyn(p);
958 p->dev = st.st_dev;
959 p->ino = st.st_ino;
960 p->refcnt = 1;
961 p->needed_by = needed_by;
962 p->name = p->buf;
963 strcpy(p->name, pathname);
964 /* Add a shortname only if name arg was not an explicit pathname. */
965 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
966 if (p->tls_image) {
967 p->tls_id = ++tls_cnt;
968 tls_align = MAXP2(tls_align, p->tls_align);
969 #ifdef TLS_ABOVE_TP
970 p->tls_offset = tls_offset + ( (tls_align-1) &
971 -(tls_offset + (uintptr_t)p->tls_image) );
972 tls_offset += p->tls_size;
973 #else
974 tls_offset += p->tls_size + p->tls_align - 1;
975 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
976 & (p->tls_align-1);
977 p->tls_offset = tls_offset;
978 #endif
979 p->new_dtv = (void *)(-sizeof(size_t) &
980 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
981 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
982 }
983
984 tail->next = p;
985 p->prev = tail;
986 tail = p;
987
988 if (DL_FDPIC) makefuncdescs(p);
989
990 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
991
992 return p;
993 }
994
995 static void load_deps(struct dso *p)
996 {
997 size_t i, ndeps=0;
998 struct dso ***deps = &p->deps, **tmp, *dep;
999 for (; p; p=p->next) {
1000 for (i=0; p->dynv[i]; i+=2) {
1001 if (p->dynv[i] != DT_NEEDED) continue;
1002 dep = load_library(p->strings + p->dynv[i+1], p);
1003 if (!dep) {
1004 error("Error loading shared library %s: %m (needed by %s)",
1005 p->strings + p->dynv[i+1], p->name);
1006 if (runtime) longjmp(*rtld_fail, 1);
1007 continue;
1008 }
1009 if (runtime) {
1010 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1011 if (!tmp) longjmp(*rtld_fail, 1);
1012 tmp[ndeps++] = dep;
1013 tmp[ndeps] = 0;
1014 *deps = tmp;
1015 }
1016 }
1017 }
1018 }
1019
1020 static void load_preload(char *s)
1021 {
1022 int tmp;
1023 char *z;
1024 for (z=s; *z; s=z) {
1025 for ( ; *s && (isspace(*s) || *s==':'); s++);
1026 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1027 tmp = *z;
1028 *z = 0;
1029 load_library(s, 0);
1030 *z = tmp;
1031 }
1032 }
1033
1034 static void make_global(struct dso *p)
1035 {
1036 for (; p; p=p->next) p->global = 1;
1037 }
1038
1039 static void do_mips_relocs(struct dso *p, size_t *got)
1040 {
1041 size_t i, j, rel[2];
1042 unsigned char *base = p->base;
1043 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1044 if (p==&ldso) {
1045 got += i;
1046 } else {
1047 while (i--) *got++ += (size_t)base;
1048 }
1049 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1050 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1051 Sym *sym = p->syms + j;
1052 rel[0] = (unsigned char *)got - base;
1053 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1054 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
1055 do_relocs(p, rel, sizeof rel, 2);
1056 }
1057 }
1058
1059 static void reloc_all(struct dso *p)
1060 {
1061 size_t dyn[DYN_CNT];
1062 for (; p; p=p->next) {
1063 if (p->relocated) continue;
1064 decode_vec(p->dynv, dyn, DYN_CNT);
1065 if (NEED_MIPS_GOT_RELOCS)
1066 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1067 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1068 2+(dyn[DT_PLTREL]==DT_RELA));
1069 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1070 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1071
1072 if (head != &ldso && p->relro_start != p->relro_end &&
1073 mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1074 && errno != ENOSYS) {
1075 error("Error relocating %s: RELRO protection failed: %m",
1076 p->name);
1077 if (runtime) longjmp(*rtld_fail, 1);
1078 }
1079
1080 p->relocated = 1;
1081 }
1082 }
1083
1084 static void kernel_mapped_dso(struct dso *p)
1085 {
1086 size_t min_addr = -1, max_addr = 0, cnt;
1087 Phdr *ph = p->phdr;
1088 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1089 if (ph->p_type == PT_DYNAMIC) {
1090 p->dynv = laddr(p, ph->p_vaddr);
1091 } else if (ph->p_type == PT_GNU_RELRO) {
1092 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1093 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1094 }
1095 if (ph->p_type != PT_LOAD) continue;
1096 if (ph->p_vaddr < min_addr)
1097 min_addr = ph->p_vaddr;
1098 if (ph->p_vaddr+ph->p_memsz > max_addr)
1099 max_addr = ph->p_vaddr+ph->p_memsz;
1100 }
1101 min_addr &= -PAGE_SIZE;
1102 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1103 p->map = p->base + min_addr;
1104 p->map_len = max_addr - min_addr;
1105 p->kernel_mapped = 1;
1106 }
1107
1108 static void do_fini()
1109 {
1110 struct dso *p;
1111 size_t dyn[DYN_CNT];
1112 for (p=fini_head; p; p=p->fini_next) {
1113 if (!p->constructed) continue;
1114 decode_vec(p->dynv, dyn, DYN_CNT);
1115 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1116 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1117 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1118 while (n--) ((void (*)(void))*--fn)();
1119 }
1120 #ifndef NO_LEGACY_INITFINI
1121 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1122 fpaddr(p, dyn[DT_FINI])();
1123 #endif
1124 }
1125 }
1126
1127 static void do_init_fini(struct dso *p)
1128 {
1129 size_t dyn[DYN_CNT];
1130 int need_locking = libc.threads_minus_1;
1131 /* Allow recursive calls that arise when a library calls
1132 * dlopen from one of its constructors, but block any
1133 * other threads until all ctors have finished. */
1134 if (need_locking) pthread_mutex_lock(&init_fini_lock);
1135 for (; p; p=p->prev) {
1136 if (p->constructed) continue;
1137 p->constructed = 1;
1138 decode_vec(p->dynv, dyn, DYN_CNT);
1139 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1140 p->fini_next = fini_head;
1141 fini_head = p;
1142 }
1143 #ifndef NO_LEGACY_INITFINI
1144 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1145 fpaddr(p, dyn[DT_INIT])();
1146 #endif
1147 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1148 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1149 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1150 while (n--) ((void (*)(void))*fn++)();
1151 }
1152 if (!need_locking && libc.threads_minus_1) {
1153 need_locking = 1;
1154 pthread_mutex_lock(&init_fini_lock);
1155 }
1156 }
1157 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1158 }
1159
1160 static void dl_debug_state(void)
1161 {
1162 }
1163
1164 weak_alias(dl_debug_state, _dl_debug_state);
1165
1166 void __reset_tls()
1167 {
1168 pthread_t self = __pthread_self();
1169 struct dso *p;
1170 for (p=head; p; p=p->next) {
1171 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1172 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1173 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1174 p->tls_size - p->tls_len);
1175 if (p->tls_id == (size_t)self->dtv[0]) break;
1176 }
1177 }
1178
1179 void *__copy_tls(unsigned char *mem)
1180 {
1181 pthread_t td;
1182 struct dso *p;
1183 void **dtv;
1184
1185 #ifdef TLS_ABOVE_TP
1186 dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1187
1188 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1189 td = (pthread_t)mem;
1190 mem += sizeof(struct pthread);
1191
1192 for (p=head; p; p=p->next) {
1193 if (!p->tls_id) continue;
1194 dtv[p->tls_id] = mem + p->tls_offset;
1195 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1196 }
1197 #else
1198 dtv = (void **)mem;
1199
1200 mem += libc.tls_size - sizeof(struct pthread);
1201 mem -= (uintptr_t)mem & (tls_align-1);
1202 td = (pthread_t)mem;
1203
1204 for (p=head; p; p=p->next) {
1205 if (!p->tls_id) continue;
1206 dtv[p->tls_id] = mem - p->tls_offset;
1207 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1208 }
1209 #endif
1210 dtv[0] = (void *)tls_cnt;
1211 td->dtv = td->dtv_copy = dtv;
1212 return td;
1213 }
1214
1215 __attribute__((__visibility__("hidden")))
1216 void *__tls_get_new(size_t *v)
1217 {
1218 pthread_t self = __pthread_self();
1219
1220 /* Block signals to make accessing new TLS async-signal-safe */
1221 sigset_t set;
1222 __block_all_sigs(&set);
1223 if (v[0]<=(size_t)self->dtv[0]) {
1224 __restore_sigs(&set);
1225 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1226 }
1227
1228 /* This is safe without any locks held because, if the caller
1229 * is able to request the Nth entry of the DTV, the DSO list
1230 * must be valid at least that far out and it was synchronized
1231 * at program startup or by an already-completed call to dlopen. */
1232 struct dso *p;
1233 for (p=head; p->tls_id != v[0]; p=p->next);
1234
1235 /* Get new DTV space from new DSO if needed */
1236 if (v[0] > (size_t)self->dtv[0]) {
1237 void **newdtv = p->new_dtv +
1238 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1239 memcpy(newdtv, self->dtv,
1240 ((size_t)self->dtv[0]+1) * sizeof(void *));
1241 newdtv[0] = (void *)v[0];
1242 self->dtv = self->dtv_copy = newdtv;
1243 }
1244
1245 /* Get new TLS memory from all new DSOs up to the requested one */
1246 unsigned char *mem;
1247 for (p=head; ; p=p->next) {
1248 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1249 mem = p->new_tls + (p->tls_size + p->tls_align)
1250 * a_fetch_add(&p->new_tls_idx,1);
1251 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1252 & (p->tls_align-1);
1253 self->dtv[p->tls_id] = mem;
1254 memcpy(mem, p->tls_image, p->tls_len);
1255 if (p->tls_id == v[0]) break;
1256 }
1257 __restore_sigs(&set);
1258 return mem + v[1] + DTP_OFFSET;
1259 }
1260
1261 static void update_tls_size()
1262 {
1263 libc.tls_size = ALIGN(
1264 (1+tls_cnt) * sizeof(void *) +
1265 tls_offset +
1266 sizeof(struct pthread) +
1267 tls_align * 2,
1268 tls_align);
1269 }
1270
1271 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1272 * following stage 2 and stage 3 functions via primitive symbolic lookup
1273 * since it does not have access to their addresses to begin with. */
1274
1275 /* Stage 2 of the dynamic linker is called after relative relocations
1276 * have been processed. It can make function calls to static functions
1277 * and access string literals and static data, but cannot use extern
1278 * symbols. Its job is to perform symbolic relocations on the dynamic
1279 * linker itself, but some of the relocations performed may need to be
1280 * replaced later due to copy relocations in the main program. */
1281
1282 void __dls2(unsigned char *base, size_t *sp)
1283 {
1284 if (DL_FDPIC) {
1285 void *p1 = (void *)sp[-2];
1286 void *p2 = (void *)sp[-1];
1287 if (!p1) {
1288 size_t *auxv, aux[AUX_CNT];
1289 for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1290 decode_vec(auxv, aux, AUX_CNT);
1291 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1292 else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1293 }
1294 app_loadmap = p2 ? p1 : 0;
1295 ldso.loadmap = p2 ? p2 : p1;
1296 ldso.base = laddr(&ldso, 0);
1297 } else {
1298 ldso.base = base;
1299 }
1300 Ehdr *ehdr = (void *)ldso.base;
1301 ldso.name = ldso.shortname = "libc.so";
1302 ldso.global = 1;
1303 ldso.phnum = ehdr->e_phnum;
1304 ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1305 ldso.phentsize = ehdr->e_phentsize;
1306 kernel_mapped_dso(&ldso);
1307 decode_dyn(&ldso);
1308
1309 if (DL_FDPIC) makefuncdescs(&ldso);
1310
1311 /* Prepare storage for to save clobbered REL addends so they
1312 * can be reused in stage 3. There should be very few. If
1313 * something goes wrong and there are a huge number, abort
1314 * instead of risking stack overflow. */
1315 size_t dyn[DYN_CNT];
1316 decode_vec(ldso.dynv, dyn, DYN_CNT);
1317 size_t *rel = laddr(&ldso, dyn[DT_REL]);
1318 size_t rel_size = dyn[DT_RELSZ];
1319 size_t symbolic_rel_cnt = 0;
1320 apply_addends_to = rel;
1321 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1322 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1323 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1324 size_t addends[symbolic_rel_cnt+1];
1325 saved_addends = addends;
1326
1327 head = &ldso;
1328 reloc_all(&ldso);
1329
1330 ldso.relocated = 0;
1331
1332 /* Call dynamic linker stage-3, __dls3, looking it up
1333 * symbolically as a barrier against moving the address
1334 * load across the above relocation processing. */
1335 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1336 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1337 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1338 }
1339
1340 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1341 * fully functional. Its job is to load (if not already loaded) and
1342 * process dependencies and relocations for the main application and
1343 * transfer control to its entry point. */
1344
1345 _Noreturn void __dls3(size_t *sp)
1346 {
1347 static struct dso app, vdso;
1348 size_t aux[AUX_CNT], *auxv;
1349 size_t i;
1350 char *env_preload=0;
1351 size_t vdso_base;
1352 int argc = *sp;
1353 char **argv = (void *)(sp+1);
1354 char **argv_orig = argv;
1355 char **envp = argv+argc+1;
1356
1357 /* Find aux vector just past environ[] and use it to initialize
1358 * global data that may be needed before we can make syscalls. */
1359 __environ = envp;
1360 for (i=argc+1; argv[i]; i++);
1361 libc.auxv = auxv = (void *)(argv+i+1);
1362 decode_vec(auxv, aux, AUX_CNT);
1363 __hwcap = aux[AT_HWCAP];
1364 libc.page_size = aux[AT_PAGESZ];
1365 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1366 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1367
1368 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1369 * use during dynamic linking. If possible it will also serve as the
1370 * thread pointer at runtime. */
1371 libc.tls_size = sizeof builtin_tls;
1372 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1373 a_crash();
1374 }
1375
1376 /* Only trust user/env if kernel says we're not suid/sgid */
1377 if (!libc.secure) {
1378 env_path = getenv("LD_LIBRARY_PATH");
1379 env_preload = getenv("LD_PRELOAD");
1380 }
1381
1382 /* If the main program was already loaded by the kernel,
1383 * AT_PHDR will point to some location other than the dynamic
1384 * linker's program headers. */
1385 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1386 size_t interp_off = 0;
1387 size_t tls_image = 0;
1388 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1389 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1390 app.phnum = aux[AT_PHNUM];
1391 app.phentsize = aux[AT_PHENT];
1392 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1393 if (phdr->p_type == PT_PHDR)
1394 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1395 else if (phdr->p_type == PT_INTERP)
1396 interp_off = (size_t)phdr->p_vaddr;
1397 else if (phdr->p_type == PT_TLS) {
1398 tls_image = phdr->p_vaddr;
1399 app.tls_len = phdr->p_filesz;
1400 app.tls_size = phdr->p_memsz;
1401 app.tls_align = phdr->p_align;
1402 }
1403 }
1404 if (DL_FDPIC) app.loadmap = app_loadmap;
1405 if (app.tls_size) app.tls_image = laddr(&app, tls_image);
1406 if (interp_off) ldso.name = laddr(&app, interp_off);
1407 if ((aux[0] & (1UL<<AT_EXECFN))
1408 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1409 app.name = (char *)aux[AT_EXECFN];
1410 else
1411 app.name = argv[0];
1412 kernel_mapped_dso(&app);
1413 } else {
1414 int fd;
1415 char *ldname = argv[0];
1416 size_t l = strlen(ldname);
1417 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1418 argv++;
1419 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1420 char *opt = argv[0]+2;
1421 *argv++ = (void *)-1;
1422 if (!*opt) {
1423 break;
1424 } else if (!memcmp(opt, "list", 5)) {
1425 ldd_mode = 1;
1426 } else if (!memcmp(opt, "library-path", 12)) {
1427 if (opt[12]=='=') env_path = opt+13;
1428 else if (opt[12]) *argv = 0;
1429 else if (*argv) env_path = *argv++;
1430 } else if (!memcmp(opt, "preload", 7)) {
1431 if (opt[7]=='=') env_preload = opt+8;
1432 else if (opt[7]) *argv = 0;
1433 else if (*argv) env_preload = *argv++;
1434 } else {
1435 argv[0] = 0;
1436 }
1437 }
1438 argv[-1] = (void *)(argc - (argv-argv_orig));
1439 if (!argv[0]) {
1440 dprintf(2, "musl libc\n"
1441 "Version %s\n"
1442 "Dynamic Program Loader\n"
1443 "Usage: %s [options] [--] pathname%s\n",
1444 __libc_get_version(), ldname,
1445 ldd_mode ? "" : " [args]");
1446 _exit(1);
1447 }
1448 fd = open(argv[0], O_RDONLY);
1449 if (fd < 0) {
1450 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1451 _exit(1);
1452 }
1453 runtime = 1;
1454 Ehdr *ehdr = (void *)map_library(fd, &app);
1455 if (!ehdr) {
1456 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1457 _exit(1);
1458 }
1459 runtime = 0;
1460 close(fd);
1461 ldso.name = ldname;
1462 app.name = argv[0];
1463 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1464 /* Find the name that would have been used for the dynamic
1465 * linker had ldd not taken its place. */
1466 if (ldd_mode) {
1467 for (i=0; i<app.phnum; i++) {
1468 if (app.phdr[i].p_type == PT_INTERP)
1469 ldso.name = (void *)(app.base
1470 + app.phdr[i].p_vaddr);
1471 }
1472 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1473 }
1474 }
1475 if (app.tls_size) {
1476 app.tls_id = tls_cnt = 1;
1477 #ifdef TLS_ABOVE_TP
1478 app.tls_offset = 0;
1479 tls_offset = app.tls_size
1480 + ( -((uintptr_t)app.tls_image + app.tls_size)
1481 & (app.tls_align-1) );
1482 #else
1483 tls_offset = app.tls_offset = app.tls_size
1484 + ( -((uintptr_t)app.tls_image + app.tls_size)
1485 & (app.tls_align-1) );
1486 #endif
1487 tls_align = MAXP2(tls_align, app.tls_align);
1488 }
1489 app.global = 1;
1490 decode_dyn(&app);
1491 if (DL_FDPIC) {
1492 makefuncdescs(&app);
1493 if (!app.loadmap) {
1494 app.loadmap = (void *)&app_dummy_loadmap;
1495 app.loadmap->nsegs = 1;
1496 app.loadmap->segs[0].addr = (size_t)app.base;
1497 app.loadmap->segs[0].p_memsz = -1;
1498 }
1499 argv[-3] = (void *)app.loadmap;
1500 }
1501
1502 /* Attach to vdso, if provided by the kernel */
1503 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1504 Ehdr *ehdr = (void *)vdso_base;
1505 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1506 vdso.phnum = ehdr->e_phnum;
1507 vdso.phentsize = ehdr->e_phentsize;
1508 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1509 if (phdr->p_type == PT_DYNAMIC)
1510 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1511 if (phdr->p_type == PT_LOAD)
1512 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1513 }
1514 vdso.name = "";
1515 vdso.shortname = "linux-gate.so.1";
1516 vdso.global = 1;
1517 vdso.relocated = 1;
1518 decode_dyn(&vdso);
1519 vdso.prev = &ldso;
1520 ldso.next = &vdso;
1521 }
1522
1523 /* Initial dso chain consists only of the app. */
1524 head = tail = &app;
1525
1526 /* Donate unused parts of app and library mapping to malloc */
1527 reclaim_gaps(&app);
1528 reclaim_gaps(&ldso);
1529
1530 /* Load preload/needed libraries, add their symbols to the global
1531 * namespace, and perform all remaining relocations. */
1532 if (env_preload) load_preload(env_preload);
1533 load_deps(&app);
1534 make_global(&app);
1535
1536 #ifndef DYNAMIC_IS_RO
1537 for (i=0; app.dynv[i]; i+=2)
1538 if (app.dynv[i]==DT_DEBUG)
1539 app.dynv[i+1] = (size_t)&debug;
1540 #endif
1541
1542 /* The main program must be relocated LAST since it may contin
1543 * copy relocations which depend on libraries' relocations. */
1544 reloc_all(app.next);
1545 reloc_all(&app);
1546
1547 update_tls_size();
1548 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1549 void *initial_tls = calloc(libc.tls_size, 1);
1550 if (!initial_tls) {
1551 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1552 argv[0], libc.tls_size);
1553 _exit(127);
1554 }
1555 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1556 a_crash();
1557 }
1558 } else {
1559 size_t tmp_tls_size = libc.tls_size;
1560 pthread_t self = __pthread_self();
1561 /* Temporarily set the tls size to the full size of
1562 * builtin_tls so that __copy_tls will use the same layout
1563 * as it did for before. Then check, just to be safe. */
1564 libc.tls_size = sizeof builtin_tls;
1565 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1566 libc.tls_size = tmp_tls_size;
1567 }
1568 static_tls_cnt = tls_cnt;
1569
1570 if (ldso_fail) _exit(127);
1571 if (ldd_mode) _exit(0);
1572
1573 /* Switch to runtime mode: any further failures in the dynamic
1574 * linker are a reportable failure rather than a fatal startup
1575 * error. */
1576 runtime = 1;
1577
1578 debug.ver = 1;
1579 debug.bp = dl_debug_state;
1580 debug.head = head;
1581 debug.base = ldso.base;
1582 debug.state = 0;
1583 _dl_debug_state();
1584
1585 __init_libc(envp, argv[0]);
1586 atexit(do_fini);
1587 errno = 0;
1588 do_init_fini(tail);
1589
1590 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1591 for(;;);
1592 }
1593
1594 void *dlopen(const char *file, int mode)
1595 {
1596 struct dso *volatile p, *orig_tail, *next;
1597 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1598 size_t i;
1599 int cs;
1600 jmp_buf jb;
1601
1602 if (!file) return head;
1603
1604 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1605 pthread_rwlock_wrlock(&lock);
1606 __inhibit_ptc();
1607
1608 p = 0;
1609 orig_tls_cnt = tls_cnt;
1610 orig_tls_offset = tls_offset;
1611 orig_tls_align = tls_align;
1612 orig_tail = tail;
1613 noload = mode & RTLD_NOLOAD;
1614
1615 rtld_fail = &jb;
1616 if (setjmp(*rtld_fail)) {
1617 /* Clean up anything new that was (partially) loaded */
1618 if (p && p->deps) for (i=0; p->deps[i]; i++)
1619 if (p->deps[i]->global < 0)
1620 p->deps[i]->global = 0;
1621 for (p=orig_tail->next; p; p=next) {
1622 next = p->next;
1623 munmap(p->map, p->map_len);
1624 while (p->td_index) {
1625 void *tmp = p->td_index->next;
1626 free(p->td_index);
1627 p->td_index = tmp;
1628 }
1629 if (p->funcdescs)
1630 free(p->funcdescs);
1631 if (p->rpath != p->rpath_orig)
1632 free(p->rpath);
1633 free(p->deps);
1634 free(p);
1635 }
1636 tls_cnt = orig_tls_cnt;
1637 tls_offset = orig_tls_offset;
1638 tls_align = orig_tls_align;
1639 tail = orig_tail;
1640 tail->next = 0;
1641 p = 0;
1642 goto end;
1643 } else p = load_library(file, head);
1644
1645 if (!p) {
1646 error(noload ?
1647 "Library %s is not already loaded" :
1648 "Error loading shared library %s: %m",
1649 file);
1650 goto end;
1651 }
1652
1653 /* First load handling */
1654 if (!p->deps) {
1655 load_deps(p);
1656 if (p->deps) for (i=0; p->deps[i]; i++)
1657 if (!p->deps[i]->global)
1658 p->deps[i]->global = -1;
1659 if (!p->global) p->global = -1;
1660 reloc_all(p);
1661 if (p->deps) for (i=0; p->deps[i]; i++)
1662 if (p->deps[i]->global < 0)
1663 p->deps[i]->global = 0;
1664 if (p->global < 0) p->global = 0;
1665 }
1666
1667 if (mode & RTLD_GLOBAL) {
1668 if (p->deps) for (i=0; p->deps[i]; i++)
1669 p->deps[i]->global = 1;
1670 p->global = 1;
1671 }
1672
1673 update_tls_size();
1674 _dl_debug_state();
1675 orig_tail = tail;
1676 end:
1677 __release_ptc();
1678 if (p) gencnt++;
1679 pthread_rwlock_unlock(&lock);
1680 if (p) do_init_fini(orig_tail);
1681 pthread_setcancelstate(cs, 0);
1682 return p;
1683 }
1684
1685 static int invalid_dso_handle(void *h)
1686 {
1687 struct dso *p;
1688 for (p=head; p; p=p->next) if (h==p) return 0;
1689 error("Invalid library handle %p", (void *)h);
1690 return 1;
1691 }
1692
1693 void *__tls_get_addr(size_t *);
1694
1695 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1696 {
1697 size_t i;
1698 uint32_t h = 0, gh = 0, *ght;
1699 Sym *sym;
1700 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1701 if (p == RTLD_DEFAULT) {
1702 p = head;
1703 } else if (p == RTLD_NEXT) {
1704 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1705 if (!p) p=head;
1706 p = p->next;
1707 }
1708 struct symdef def = find_sym(p, s, 0);
1709 if (!def.sym) goto failed;
1710 if ((def.sym->st_info&0xf) == STT_TLS)
1711 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1712 return laddr(def.dso, def.sym->st_value);
1713 }
1714 if (invalid_dso_handle(p))
1715 return 0;
1716 if ((ght = p->ghashtab)) {
1717 gh = gnu_hash(s);
1718 sym = gnu_lookup(gh, ght, p, s);
1719 } else {
1720 h = sysv_hash(s);
1721 sym = sysv_lookup(s, h, p);
1722 }
1723 if (sym && (sym->st_info&0xf) == STT_TLS)
1724 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1725 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1726 return laddr(p, sym->st_value);
1727 if (p->deps) for (i=0; p->deps[i]; i++) {
1728 if ((ght = p->deps[i]->ghashtab)) {
1729 if (!gh) gh = gnu_hash(s);
1730 sym = gnu_lookup(gh, ght, p->deps[i], s);
1731 } else {
1732 if (!h) h = sysv_hash(s);
1733 sym = sysv_lookup(s, h, p->deps[i]);
1734 }
1735 if (sym && (sym->st_info&0xf) == STT_TLS)
1736 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1737 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1738 return laddr(p->deps[i], sym->st_value);
1739 }
1740 failed:
1741 error("Symbol not found: %s", s);
1742 return 0;
1743 }
1744
1745 int __dladdr(const void *addr, Dl_info *info)
1746 {
1747 struct dso *p;
1748 Sym *sym;
1749 uint32_t nsym;
1750 char *strings;
1751 void *best = 0;
1752 char *bestname;
1753
1754 pthread_rwlock_rdlock(&lock);
1755 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1756 pthread_rwlock_unlock(&lock);
1757
1758 if (!p) return 0;
1759
1760 sym = p->syms;
1761 strings = p->strings;
1762 nsym = count_syms(p);
1763
1764 for (; nsym; nsym--, sym++) {
1765 if (sym->st_value
1766 && (1<<(sym->st_info&0xf) & OK_TYPES)
1767 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1768 void *symaddr = laddr(p, sym->st_value);
1769 if (symaddr > addr || symaddr < best)
1770 continue;
1771 best = symaddr;
1772 bestname = strings + sym->st_name;
1773 if (addr == symaddr)
1774 break;
1775 }
1776 }
1777
1778 if (!best) return 0;
1779
1780 info->dli_fname = p->name;
1781 info->dli_fbase = p->base;
1782 info->dli_sname = bestname;
1783 info->dli_saddr = best;
1784
1785 return 1;
1786 }
1787
1788 __attribute__((__visibility__("hidden")))
1789 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1790 {
1791 void *res;
1792 pthread_rwlock_rdlock(&lock);
1793 res = do_dlsym(p, s, ra);
1794 pthread_rwlock_unlock(&lock);
1795 return res;
1796 }
1797
1798 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1799 {
1800 struct dso *current;
1801 struct dl_phdr_info info;
1802 int ret = 0;
1803 for(current = head; current;) {
1804 info.dlpi_addr = (uintptr_t)current->base;
1805 info.dlpi_name = current->name;
1806 info.dlpi_phdr = current->phdr;
1807 info.dlpi_phnum = current->phnum;
1808 info.dlpi_adds = gencnt;
1809 info.dlpi_subs = 0;
1810 info.dlpi_tls_modid = current->tls_id;
1811 info.dlpi_tls_data = current->tls_image;
1812
1813 ret = (callback)(&info, sizeof (info), data);
1814
1815 if (ret != 0) break;
1816
1817 pthread_rwlock_rdlock(&lock);
1818 current = current->next;
1819 pthread_rwlock_unlock(&lock);
1820 }
1821 return ret;
1822 }
1823 #else
1824 static int invalid_dso_handle(void *h)
1825 {
1826 error("Invalid library handle %p", (void *)h);
1827 return 1;
1828 }
1829 void *dlopen(const char *file, int mode)
1830 {
1831 error("Dynamic loading not supported");
1832 return 0;
1833 }
1834 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1835 {
1836 error("Symbol not found: %s", s);
1837 return 0;
1838 }
1839 int __dladdr (const void *addr, Dl_info *info)
1840 {
1841 return 0;
1842 }
1843 #endif
1844
1845 int __dlinfo(void *dso, int req, void *res)
1846 {
1847 if (invalid_dso_handle(dso)) return -1;
1848 if (req != RTLD_DI_LINKMAP) {
1849 error("Unsupported request %d", req);
1850 return -1;
1851 }
1852 *(struct link_map **)res = dso;
1853 return 0;
1854 }
1855
1856 char *dlerror()
1857 {
1858 pthread_t self = __pthread_self();
1859 if (!self->dlerror_flag) return 0;
1860 self->dlerror_flag = 0;
1861 char *s = self->dlerror_buf;
1862 if (s == (void *)-1)
1863 return "Dynamic linker failed to allocate memory for error message";
1864 else
1865 return s;
1866 }
1867
1868 int dlclose(void *p)
1869 {
1870 return invalid_dso_handle(p);
1871 }
1872
1873 void __dl_thread_cleanup(void)
1874 {
1875 pthread_t self = __pthread_self();
1876 if (self->dlerror_buf != (void *)-1)
1877 free(self->dlerror_buf);
1878 }
1879
1880 static void error(const char *fmt, ...)
1881 {
1882 va_list ap;
1883 va_start(ap, fmt);
1884 #ifdef SHARED
1885 if (!runtime) {
1886 vdprintf(2, fmt, ap);
1887 dprintf(2, "\n");
1888 ldso_fail = 1;
1889 va_end(ap);
1890 return;
1891 }
1892 #endif
1893 pthread_t self = __pthread_self();
1894 if (self->dlerror_buf != (void *)-1)
1895 free(self->dlerror_buf);
1896 size_t len = vsnprintf(0, 0, fmt, ap);
1897 va_end(ap);
1898 char *buf = malloc(len+1);
1899 if (buf) {
1900 va_start(ap, fmt);
1901 vsnprintf(buf, len+1, fmt, ap);
1902 va_end(ap);
1903 } else {
1904 buf = (void *)-1;
1905 }
1906 self->dlerror_buf = buf;
1907 self->dlerror_flag = 1;
1908 }
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