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 | #define MAXP2(a,b) (-(-(a)&-(b)))
|
---|
27 | #define ALIGN(x,y) ((x)+(y)-1 & -(y))
|
---|
28 |
|
---|
29 | struct debug {
|
---|
30 | int ver;
|
---|
31 | void *head;
|
---|
32 | void (*bp)(void);
|
---|
33 | int state;
|
---|
34 | void *base;
|
---|
35 | };
|
---|
36 |
|
---|
37 | struct td_index {
|
---|
38 | size_t args[2];
|
---|
39 | struct td_index *next;
|
---|
40 | };
|
---|
41 |
|
---|
42 | struct dso {
|
---|
43 | #if DL_FDPIC
|
---|
44 | struct fdpic_loadmap *loadmap;
|
---|
45 | #else
|
---|
46 | unsigned char *base;
|
---|
47 | #endif
|
---|
48 | char *name;
|
---|
49 | size_t *dynv;
|
---|
50 | struct dso *next, *prev;
|
---|
51 |
|
---|
52 | Phdr *phdr;
|
---|
53 | int phnum;
|
---|
54 | size_t phentsize;
|
---|
55 | Sym *syms;
|
---|
56 | Elf_Symndx *hashtab;
|
---|
57 | uint32_t *ghashtab;
|
---|
58 | int16_t *versym;
|
---|
59 | char *strings;
|
---|
60 | struct dso *syms_next, *lazy_next;
|
---|
61 | size_t *lazy, lazy_cnt;
|
---|
62 | unsigned char *map;
|
---|
63 | size_t map_len;
|
---|
64 | dev_t dev;
|
---|
65 | ino_t ino;
|
---|
66 | char relocated;
|
---|
67 | char constructed;
|
---|
68 | char kernel_mapped;
|
---|
69 | struct dso **deps, *needed_by;
|
---|
70 | char *rpath_orig, *rpath;
|
---|
71 | struct tls_module tls;
|
---|
72 | size_t tls_id;
|
---|
73 | size_t relro_start, relro_end;
|
---|
74 | void **new_dtv;
|
---|
75 | unsigned char *new_tls;
|
---|
76 | volatile int new_dtv_idx, new_tls_idx;
|
---|
77 | struct td_index *td_index;
|
---|
78 | struct dso *fini_next;
|
---|
79 | char *shortname;
|
---|
80 | #if DL_FDPIC
|
---|
81 | unsigned char *base;
|
---|
82 | #else
|
---|
83 | struct fdpic_loadmap *loadmap;
|
---|
84 | #endif
|
---|
85 | struct funcdesc {
|
---|
86 | void *addr;
|
---|
87 | size_t *got;
|
---|
88 | } *funcdescs;
|
---|
89 | size_t *got;
|
---|
90 | char buf[];
|
---|
91 | };
|
---|
92 |
|
---|
93 | struct symdef {
|
---|
94 | Sym *sym;
|
---|
95 | struct dso *dso;
|
---|
96 | };
|
---|
97 |
|
---|
98 | int __init_tp(void *);
|
---|
99 | void __init_libc(char **, char *);
|
---|
100 | void *__copy_tls(unsigned char *);
|
---|
101 |
|
---|
102 | __attribute__((__visibility__("hidden")))
|
---|
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, *syms_tail, *lazy_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 struct tls_module *tls_tail;
|
---|
127 | static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
|
---|
128 | static size_t static_tls_cnt;
|
---|
129 | static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
|
---|
130 | static struct fdpic_loadmap *app_loadmap;
|
---|
131 | static struct fdpic_dummy_loadmap app_dummy_loadmap;
|
---|
132 | static struct dso *const nodeps_dummy;
|
---|
133 |
|
---|
134 | struct debug *_dl_debug_addr = &debug;
|
---|
135 |
|
---|
136 | #ifndef __c2__
|
---|
137 | __attribute__((__visibility__("hidden")))
|
---|
138 | void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
|
---|
139 |
|
---|
140 | __attribute__((__visibility__("hidden")))
|
---|
141 | extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
|
---|
142 |
|
---|
143 | weak_alias(__init_array_start, __init_array_end);
|
---|
144 | weak_alias(__fini_array_start, __fini_array_end);
|
---|
145 | #else
|
---|
146 | void(*const __init_array_start)(void) = 0, (*const __fini_array_start)(void) = 0;
|
---|
147 | #define __init_array_end __init_array_start
|
---|
148 | #define __fini_array_end __fini_array_start
|
---|
149 | #endif
|
---|
150 |
|
---|
151 | static int dl_strcmp(const char *l, const char *r)
|
---|
152 | {
|
---|
153 | for (; *l==*r && *l; l++, r++);
|
---|
154 | return *(unsigned char *)l - *(unsigned char *)r;
|
---|
155 | }
|
---|
156 | #define strcmp(l,r) dl_strcmp(l,r)
|
---|
157 |
|
---|
158 | /* Compute load address for a virtual address in a given dso. */
|
---|
159 | #if DL_FDPIC
|
---|
160 | static void *laddr(const struct dso *p, size_t v)
|
---|
161 | {
|
---|
162 | size_t j=0;
|
---|
163 | if (!p->loadmap) return p->base + v;
|
---|
164 | for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
|
---|
165 | return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
|
---|
166 | }
|
---|
167 | #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
|
---|
168 | laddr(p, v), (p)->got })
|
---|
169 | #else
|
---|
170 | #define laddr(p, v) (void *)((p)->base + (v))
|
---|
171 | #define fpaddr(p, v) ((void (*)())laddr(p, v))
|
---|
172 | #endif
|
---|
173 |
|
---|
174 | static void decode_vec(size_t *v, size_t *a, size_t cnt)
|
---|
175 | {
|
---|
176 | size_t i;
|
---|
177 | for (i=0; i<cnt; i++) a[i] = 0;
|
---|
178 | for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
|
---|
179 | a[0] |= 1UL<<v[0];
|
---|
180 | a[v[0]] = v[1];
|
---|
181 | }
|
---|
182 | }
|
---|
183 |
|
---|
184 | static int search_vec(size_t *v, size_t *r, size_t key)
|
---|
185 | {
|
---|
186 | for (; v[0]!=key; v+=2)
|
---|
187 | if (!v[0]) return 0;
|
---|
188 | *r = v[1];
|
---|
189 | return 1;
|
---|
190 | }
|
---|
191 |
|
---|
192 | static uint32_t sysv_hash(const char *s0)
|
---|
193 | {
|
---|
194 | const unsigned char *s = (void *)s0;
|
---|
195 | uint_fast32_t h = 0;
|
---|
196 | while (*s) {
|
---|
197 | h = 16*h + *s++;
|
---|
198 | h ^= h>>24 & 0xf0;
|
---|
199 | }
|
---|
200 | return h & 0xfffffff;
|
---|
201 | }
|
---|
202 |
|
---|
203 | static uint32_t gnu_hash(const char *s0)
|
---|
204 | {
|
---|
205 | const unsigned char *s = (void *)s0;
|
---|
206 | uint_fast32_t h = 5381;
|
---|
207 | for (; *s; s++)
|
---|
208 | h += h*32 + *s;
|
---|
209 | return h;
|
---|
210 | }
|
---|
211 |
|
---|
212 | static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
|
---|
213 | {
|
---|
214 | size_t i;
|
---|
215 | Sym *syms = dso->syms;
|
---|
216 | Elf_Symndx *hashtab = dso->hashtab;
|
---|
217 | char *strings = dso->strings;
|
---|
218 | for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
|
---|
219 | if ((!dso->versym || dso->versym[i] >= 0)
|
---|
220 | && (!strcmp(s, strings+syms[i].st_name)))
|
---|
221 | return syms+i;
|
---|
222 | }
|
---|
223 | return 0;
|
---|
224 | }
|
---|
225 |
|
---|
226 | static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
|
---|
227 | {
|
---|
228 | uint32_t nbuckets = hashtab[0];
|
---|
229 | uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
|
---|
230 | uint32_t i = buckets[h1 % nbuckets];
|
---|
231 |
|
---|
232 | if (!i) return 0;
|
---|
233 |
|
---|
234 | uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
|
---|
235 |
|
---|
236 | for (h1 |= 1; ; i++) {
|
---|
237 | uint32_t h2 = *hashval++;
|
---|
238 | if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
|
---|
239 | && !strcmp(s, dso->strings + dso->syms[i].st_name))
|
---|
240 | return dso->syms+i;
|
---|
241 | if (h2 & 1) break;
|
---|
242 | }
|
---|
243 |
|
---|
244 | return 0;
|
---|
245 | }
|
---|
246 |
|
---|
247 | static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
|
---|
248 | {
|
---|
249 | const size_t *bloomwords = (const void *)(hashtab+4);
|
---|
250 | size_t f = bloomwords[fofs & (hashtab[2]-1)];
|
---|
251 | if (!(f & fmask)) return 0;
|
---|
252 |
|
---|
253 | f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
|
---|
254 | if (!(f & 1)) return 0;
|
---|
255 |
|
---|
256 | return gnu_lookup(h1, hashtab, dso, s);
|
---|
257 | }
|
---|
258 |
|
---|
259 | #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
|
---|
260 | #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
|
---|
261 |
|
---|
262 | #ifndef ARCH_SYM_REJECT_UND
|
---|
263 | #define ARCH_SYM_REJECT_UND(s) 0
|
---|
264 | #endif
|
---|
265 |
|
---|
266 | static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
|
---|
267 | {
|
---|
268 | uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
|
---|
269 | size_t ghm = 1ul << gh % (8*sizeof(size_t));
|
---|
270 | struct symdef def = {0};
|
---|
271 | for (; dso; dso=dso->syms_next) {
|
---|
272 | Sym *sym;
|
---|
273 | if ((ght = dso->ghashtab)) {
|
---|
274 | sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
|
---|
275 | } else {
|
---|
276 | if (!h) h = sysv_hash(s);
|
---|
277 | sym = sysv_lookup(s, h, dso);
|
---|
278 | }
|
---|
279 | if (!sym) continue;
|
---|
280 | if (!sym->st_shndx)
|
---|
281 | if (need_def || (sym->st_info&0xf) == STT_TLS
|
---|
282 | || ARCH_SYM_REJECT_UND(sym))
|
---|
283 | continue;
|
---|
284 | if (!sym->st_value)
|
---|
285 | if ((sym->st_info&0xf) != STT_TLS)
|
---|
286 | continue;
|
---|
287 | if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
|
---|
288 | if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
|
---|
289 | def.sym = sym;
|
---|
290 | def.dso = dso;
|
---|
291 | break;
|
---|
292 | }
|
---|
293 | return def;
|
---|
294 | }
|
---|
295 |
|
---|
296 | __attribute__((__visibility__("hidden")))
|
---|
297 | ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
|
---|
298 |
|
---|
299 | static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
|
---|
300 | {
|
---|
301 | unsigned char *base = dso->base;
|
---|
302 | Sym *syms = dso->syms;
|
---|
303 | char *strings = dso->strings;
|
---|
304 | Sym *sym;
|
---|
305 | const char *name;
|
---|
306 | void *ctx;
|
---|
307 | int type;
|
---|
308 | int sym_index;
|
---|
309 | struct symdef def;
|
---|
310 | size_t *reloc_addr;
|
---|
311 | size_t sym_val;
|
---|
312 | size_t tls_val;
|
---|
313 | size_t addend;
|
---|
314 | int skip_relative = 0, reuse_addends = 0, save_slot = 0;
|
---|
315 |
|
---|
316 | if (dso == &ldso) {
|
---|
317 | /* Only ldso's REL table needs addend saving/reuse. */
|
---|
318 | if (rel == apply_addends_to)
|
---|
319 | reuse_addends = 1;
|
---|
320 | skip_relative = 1;
|
---|
321 | }
|
---|
322 |
|
---|
323 | for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
|
---|
324 | if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
|
---|
325 | type = R_TYPE(rel[1]);
|
---|
326 | if (type == REL_NONE) continue;
|
---|
327 | reloc_addr = laddr(dso, rel[0]);
|
---|
328 |
|
---|
329 | if (stride > 2) {
|
---|
330 | addend = rel[2];
|
---|
331 | } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
|
---|
332 | addend = 0;
|
---|
333 | } else if (reuse_addends) {
|
---|
334 | /* Save original addend in stage 2 where the dso
|
---|
335 | * chain consists of just ldso; otherwise read back
|
---|
336 | * saved addend since the inline one was clobbered. */
|
---|
337 | if (head==&ldso)
|
---|
338 | saved_addends[save_slot] = *reloc_addr;
|
---|
339 | addend = saved_addends[save_slot++];
|
---|
340 | } else {
|
---|
341 | addend = *reloc_addr;
|
---|
342 | }
|
---|
343 |
|
---|
344 | sym_index = R_SYM(rel[1]);
|
---|
345 | if (sym_index) {
|
---|
346 | sym = syms + sym_index;
|
---|
347 | name = strings + sym->st_name;
|
---|
348 | ctx = type==REL_COPY ? head->syms_next : head;
|
---|
349 | def = (sym->st_info&0xf) == STT_SECTION
|
---|
350 | ? (struct symdef){ .dso = dso, .sym = sym }
|
---|
351 | : find_sym(ctx, name, type==REL_PLT);
|
---|
352 | if (!def.sym && (sym->st_shndx != SHN_UNDEF
|
---|
353 | || sym->st_info>>4 != STB_WEAK)) {
|
---|
354 | if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
|
---|
355 | dso->lazy[3*dso->lazy_cnt+0] = rel[0];
|
---|
356 | dso->lazy[3*dso->lazy_cnt+1] = rel[1];
|
---|
357 | dso->lazy[3*dso->lazy_cnt+2] = addend;
|
---|
358 | dso->lazy_cnt++;
|
---|
359 | continue;
|
---|
360 | }
|
---|
361 | error("Error relocating %s: %s: symbol not found",
|
---|
362 | dso->name, name);
|
---|
363 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
364 | continue;
|
---|
365 | }
|
---|
366 | } else {
|
---|
367 | sym = 0;
|
---|
368 | def.sym = 0;
|
---|
369 | def.dso = dso;
|
---|
370 | }
|
---|
371 |
|
---|
372 | sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
|
---|
373 | tls_val = def.sym ? def.sym->st_value : 0;
|
---|
374 |
|
---|
375 | switch(type) {
|
---|
376 | case REL_NONE:
|
---|
377 | break;
|
---|
378 | case REL_OFFSET:
|
---|
379 | addend -= (size_t)reloc_addr;
|
---|
380 | case REL_SYMBOLIC:
|
---|
381 | case REL_GOT:
|
---|
382 | case REL_PLT:
|
---|
383 | *reloc_addr = sym_val + addend;
|
---|
384 | break;
|
---|
385 | case REL_RELATIVE:
|
---|
386 | *reloc_addr = (size_t)base + addend;
|
---|
387 | break;
|
---|
388 | case REL_SYM_OR_REL:
|
---|
389 | if (sym) *reloc_addr = sym_val + addend;
|
---|
390 | else *reloc_addr = (size_t)base + addend;
|
---|
391 | break;
|
---|
392 | case REL_COPY:
|
---|
393 | memcpy(reloc_addr, (void *)sym_val, sym->st_size);
|
---|
394 | break;
|
---|
395 | case REL_OFFSET32:
|
---|
396 | *(uint32_t *)reloc_addr = sym_val + addend
|
---|
397 | - (size_t)reloc_addr;
|
---|
398 | break;
|
---|
399 | case REL_FUNCDESC:
|
---|
400 | *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
|
---|
401 | + (def.sym - def.dso->syms)) : 0;
|
---|
402 | break;
|
---|
403 | case REL_FUNCDESC_VAL:
|
---|
404 | if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
|
---|
405 | else *reloc_addr = sym_val;
|
---|
406 | reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
|
---|
407 | break;
|
---|
408 | case REL_DTPMOD:
|
---|
409 | *reloc_addr = def.dso->tls_id;
|
---|
410 | break;
|
---|
411 | case REL_DTPOFF:
|
---|
412 | *reloc_addr = tls_val + addend - DTP_OFFSET;
|
---|
413 | break;
|
---|
414 | #ifdef TLS_ABOVE_TP
|
---|
415 | case REL_TPOFF:
|
---|
416 | *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
|
---|
417 | break;
|
---|
418 | #else
|
---|
419 | case REL_TPOFF:
|
---|
420 | *reloc_addr = tls_val - def.dso->tls.offset + addend;
|
---|
421 | break;
|
---|
422 | case REL_TPOFF_NEG:
|
---|
423 | *reloc_addr = def.dso->tls.offset - tls_val + addend;
|
---|
424 | break;
|
---|
425 | #endif
|
---|
426 | case REL_TLSDESC:
|
---|
427 | if (stride<3) addend = reloc_addr[1];
|
---|
428 | if (runtime && def.dso->tls_id >= static_tls_cnt) {
|
---|
429 | struct td_index *new = malloc(sizeof *new);
|
---|
430 | if (!new) {
|
---|
431 | error(
|
---|
432 | "Error relocating %s: cannot allocate TLSDESC for %s",
|
---|
433 | dso->name, sym ? name : "(local)" );
|
---|
434 | longjmp(*rtld_fail, 1);
|
---|
435 | }
|
---|
436 | new->next = dso->td_index;
|
---|
437 | dso->td_index = new;
|
---|
438 | new->args[0] = def.dso->tls_id;
|
---|
439 | new->args[1] = tls_val + addend;
|
---|
440 | reloc_addr[0] = (size_t)__tlsdesc_dynamic;
|
---|
441 | reloc_addr[1] = (size_t)new;
|
---|
442 | } else {
|
---|
443 | reloc_addr[0] = (size_t)__tlsdesc_static;
|
---|
444 | #ifdef TLS_ABOVE_TP
|
---|
445 | reloc_addr[1] = tls_val + def.dso->tls.offset
|
---|
446 | + TPOFF_K + addend;
|
---|
447 | #else
|
---|
448 | reloc_addr[1] = tls_val - def.dso->tls.offset
|
---|
449 | + addend;
|
---|
450 | #endif
|
---|
451 | }
|
---|
452 | break;
|
---|
453 | default:
|
---|
454 | error("Error relocating %s: unsupported relocation type %d",
|
---|
455 | dso->name, type);
|
---|
456 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
457 | continue;
|
---|
458 | }
|
---|
459 | }
|
---|
460 | }
|
---|
461 |
|
---|
462 | static void redo_lazy_relocs()
|
---|
463 | {
|
---|
464 | struct dso *p = lazy_head, *next;
|
---|
465 | lazy_head = 0;
|
---|
466 | for (; p; p=next) {
|
---|
467 | next = p->lazy_next;
|
---|
468 | size_t size = p->lazy_cnt*3*sizeof(size_t);
|
---|
469 | p->lazy_cnt = 0;
|
---|
470 | do_relocs(p, p->lazy, size, 3);
|
---|
471 | if (p->lazy_cnt) {
|
---|
472 | p->lazy_next = lazy_head;
|
---|
473 | lazy_head = p;
|
---|
474 | } else {
|
---|
475 | free(p->lazy);
|
---|
476 | p->lazy = 0;
|
---|
477 | p->lazy_next = 0;
|
---|
478 | }
|
---|
479 | }
|
---|
480 | }
|
---|
481 |
|
---|
482 | /* A huge hack: to make up for the wastefulness of shared libraries
|
---|
483 | * needing at least a page of dirty memory even if they have no global
|
---|
484 | * data, we reclaim the gaps at the beginning and end of writable maps
|
---|
485 | * and "donate" them to the heap by setting up minimal malloc
|
---|
486 | * structures and then freeing them. */
|
---|
487 |
|
---|
488 | static void reclaim(struct dso *dso, size_t start, size_t end)
|
---|
489 | {
|
---|
490 | size_t *a, *z;
|
---|
491 | if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
|
---|
492 | if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
|
---|
493 | start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
|
---|
494 | end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
|
---|
495 | if (start>end || end-start < 4*sizeof(size_t)) return;
|
---|
496 | a = laddr(dso, start);
|
---|
497 | z = laddr(dso, end);
|
---|
498 | a[-2] = 1;
|
---|
499 | a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
|
---|
500 | z[1] = 1;
|
---|
501 | free(a);
|
---|
502 | }
|
---|
503 |
|
---|
504 | static void reclaim_gaps(struct dso *dso)
|
---|
505 | {
|
---|
506 | Phdr *ph = dso->phdr;
|
---|
507 | size_t phcnt = dso->phnum;
|
---|
508 |
|
---|
509 | if (DL_FDPIC) return; // FIXME
|
---|
510 | for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
|
---|
511 | if (ph->p_type!=PT_LOAD) continue;
|
---|
512 | if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
|
---|
513 | reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
|
---|
514 | reclaim(dso, ph->p_vaddr+ph->p_memsz,
|
---|
515 | ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
|
---|
516 | }
|
---|
517 | }
|
---|
518 |
|
---|
519 | static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
|
---|
520 | {
|
---|
521 | static int no_map_fixed;
|
---|
522 | char *q;
|
---|
523 | if (!no_map_fixed) {
|
---|
524 | q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
|
---|
525 | if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
|
---|
526 | return q;
|
---|
527 | no_map_fixed = 1;
|
---|
528 | }
|
---|
529 | /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
|
---|
530 | if (flags & MAP_ANONYMOUS) {
|
---|
531 | memset(p, 0, n);
|
---|
532 | return p;
|
---|
533 | }
|
---|
534 | ssize_t r;
|
---|
535 | if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
|
---|
536 | for (q=p; n; q+=r, off+=r, n-=r) {
|
---|
537 | r = read(fd, q, n);
|
---|
538 | if (r < 0 && errno != EINTR) return MAP_FAILED;
|
---|
539 | if (!r) {
|
---|
540 | memset(q, 0, n);
|
---|
541 | break;
|
---|
542 | }
|
---|
543 | }
|
---|
544 | return p;
|
---|
545 | }
|
---|
546 |
|
---|
547 | static void unmap_library(struct dso *dso)
|
---|
548 | {
|
---|
549 | if (dso->loadmap) {
|
---|
550 | size_t i;
|
---|
551 | for (i=0; i<dso->loadmap->nsegs; i++) {
|
---|
552 | if (!dso->loadmap->segs[i].p_memsz)
|
---|
553 | continue;
|
---|
554 | munmap((void *)dso->loadmap->segs[i].addr,
|
---|
555 | dso->loadmap->segs[i].p_memsz);
|
---|
556 | }
|
---|
557 | free(dso->loadmap);
|
---|
558 | } else if (dso->map && dso->map_len) {
|
---|
559 | munmap(dso->map, dso->map_len);
|
---|
560 | }
|
---|
561 | }
|
---|
562 |
|
---|
563 | static void *map_library(int fd, struct dso *dso)
|
---|
564 | {
|
---|
565 | Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
|
---|
566 | void *allocated_buf=0;
|
---|
567 | size_t phsize;
|
---|
568 | size_t addr_min=SIZE_MAX, addr_max=0, map_len;
|
---|
569 | size_t this_min, this_max;
|
---|
570 | size_t nsegs = 0;
|
---|
571 | off_t off_start;
|
---|
572 | Ehdr *eh;
|
---|
573 | Phdr *ph, *ph0;
|
---|
574 | unsigned prot;
|
---|
575 | unsigned char *map=MAP_FAILED, *base;
|
---|
576 | size_t dyn=0;
|
---|
577 | size_t tls_image=0;
|
---|
578 | size_t i;
|
---|
579 |
|
---|
580 | ssize_t l = read(fd, buf, sizeof buf);
|
---|
581 | eh = buf;
|
---|
582 | if (l<0) return 0;
|
---|
583 | if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
|
---|
584 | goto noexec;
|
---|
585 | phsize = eh->e_phentsize * eh->e_phnum;
|
---|
586 | if (phsize > sizeof buf - sizeof *eh) {
|
---|
587 | allocated_buf = malloc(phsize);
|
---|
588 | if (!allocated_buf) return 0;
|
---|
589 | l = pread(fd, allocated_buf, phsize, eh->e_phoff);
|
---|
590 | if (l < 0) goto error;
|
---|
591 | if (l != phsize) goto noexec;
|
---|
592 | ph = ph0 = allocated_buf;
|
---|
593 | } else if (eh->e_phoff + phsize > l) {
|
---|
594 | l = pread(fd, buf+1, phsize, eh->e_phoff);
|
---|
595 | if (l < 0) goto error;
|
---|
596 | if (l != phsize) goto noexec;
|
---|
597 | ph = ph0 = (void *)(buf + 1);
|
---|
598 | } else {
|
---|
599 | ph = ph0 = (void *)((char *)buf + eh->e_phoff);
|
---|
600 | }
|
---|
601 | for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
|
---|
602 | if (ph->p_type == PT_DYNAMIC) {
|
---|
603 | dyn = ph->p_vaddr;
|
---|
604 | } else if (ph->p_type == PT_TLS) {
|
---|
605 | tls_image = ph->p_vaddr;
|
---|
606 | dso->tls.align = ph->p_align;
|
---|
607 | dso->tls.len = ph->p_filesz;
|
---|
608 | dso->tls.size = ph->p_memsz;
|
---|
609 | } else if (ph->p_type == PT_GNU_RELRO) {
|
---|
610 | dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
|
---|
611 | dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
|
---|
612 | }
|
---|
613 | if (ph->p_type != PT_LOAD) continue;
|
---|
614 | nsegs++;
|
---|
615 | if (ph->p_vaddr < addr_min) {
|
---|
616 | addr_min = ph->p_vaddr;
|
---|
617 | off_start = ph->p_offset;
|
---|
618 | prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
|
---|
619 | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
|
---|
620 | ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
|
---|
621 | }
|
---|
622 | if (ph->p_vaddr+ph->p_memsz > addr_max) {
|
---|
623 | addr_max = ph->p_vaddr+ph->p_memsz;
|
---|
624 | }
|
---|
625 | }
|
---|
626 | if (!dyn) goto noexec;
|
---|
627 | if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
|
---|
628 | dso->loadmap = calloc(1, sizeof *dso->loadmap
|
---|
629 | + nsegs * sizeof *dso->loadmap->segs);
|
---|
630 | if (!dso->loadmap) goto error;
|
---|
631 | dso->loadmap->nsegs = nsegs;
|
---|
632 | for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
|
---|
633 | if (ph->p_type != PT_LOAD) continue;
|
---|
634 | prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
|
---|
635 | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
|
---|
636 | ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
|
---|
637 | map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
|
---|
638 | prot, MAP_PRIVATE,
|
---|
639 | fd, ph->p_offset & -PAGE_SIZE);
|
---|
640 | if (map == MAP_FAILED) {
|
---|
641 | unmap_library(dso);
|
---|
642 | goto error;
|
---|
643 | }
|
---|
644 | dso->loadmap->segs[i].addr = (size_t)map +
|
---|
645 | (ph->p_vaddr & PAGE_SIZE-1);
|
---|
646 | dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
|
---|
647 | dso->loadmap->segs[i].p_memsz = ph->p_memsz;
|
---|
648 | i++;
|
---|
649 | if (prot & PROT_WRITE) {
|
---|
650 | size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
|
---|
651 | + ph->p_filesz;
|
---|
652 | size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
653 | size_t pgend = brk + ph->p_memsz - ph->p_filesz
|
---|
654 | + PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
655 | if (pgend > pgbrk && mmap_fixed(map+pgbrk,
|
---|
656 | pgend-pgbrk, prot,
|
---|
657 | MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
|
---|
658 | -1, off_start) == MAP_FAILED)
|
---|
659 | goto error;
|
---|
660 | memset(map + brk, 0, pgbrk-brk);
|
---|
661 | }
|
---|
662 | }
|
---|
663 | map = (void *)dso->loadmap->segs[0].addr;
|
---|
664 | map_len = 0;
|
---|
665 | goto done_mapping;
|
---|
666 | }
|
---|
667 | addr_max += PAGE_SIZE-1;
|
---|
668 | addr_max &= -PAGE_SIZE;
|
---|
669 | addr_min &= -PAGE_SIZE;
|
---|
670 | off_start &= -PAGE_SIZE;
|
---|
671 | map_len = addr_max - addr_min + off_start;
|
---|
672 | /* The first time, we map too much, possibly even more than
|
---|
673 | * the length of the file. This is okay because we will not
|
---|
674 | * use the invalid part; we just need to reserve the right
|
---|
675 | * amount of virtual address space to map over later. */
|
---|
676 | map = DL_NOMMU_SUPPORT
|
---|
677 | ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
|
---|
678 | MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
|
---|
679 | : mmap((void *)addr_min, map_len, prot,
|
---|
680 | MAP_PRIVATE, fd, off_start);
|
---|
681 | if (map==MAP_FAILED) goto error;
|
---|
682 | dso->map = map;
|
---|
683 | dso->map_len = map_len;
|
---|
684 | /* If the loaded file is not relocatable and the requested address is
|
---|
685 | * not available, then the load operation must fail. */
|
---|
686 | if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
|
---|
687 | errno = EBUSY;
|
---|
688 | goto error;
|
---|
689 | }
|
---|
690 | base = map - addr_min;
|
---|
691 | dso->phdr = 0;
|
---|
692 | dso->phnum = 0;
|
---|
693 | for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
|
---|
694 | if (ph->p_type != PT_LOAD) continue;
|
---|
695 | /* Check if the programs headers are in this load segment, and
|
---|
696 | * if so, record the address for use by dl_iterate_phdr. */
|
---|
697 | if (!dso->phdr && eh->e_phoff >= ph->p_offset
|
---|
698 | && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
|
---|
699 | dso->phdr = (void *)(base + ph->p_vaddr
|
---|
700 | + (eh->e_phoff-ph->p_offset));
|
---|
701 | dso->phnum = eh->e_phnum;
|
---|
702 | dso->phentsize = eh->e_phentsize;
|
---|
703 | }
|
---|
704 | /* Reuse the existing mapping for the lowest-address LOAD */
|
---|
705 | if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
|
---|
706 | continue;
|
---|
707 | this_min = ph->p_vaddr & -PAGE_SIZE;
|
---|
708 | this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
709 | off_start = ph->p_offset & -PAGE_SIZE;
|
---|
710 | prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
|
---|
711 | ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
|
---|
712 | ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
|
---|
713 | if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
|
---|
714 | goto error;
|
---|
715 | if (ph->p_memsz > ph->p_filesz) {
|
---|
716 | size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
|
---|
717 | size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
|
---|
718 | memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
|
---|
719 | 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)
|
---|
720 | goto error;
|
---|
721 | }
|
---|
722 | }
|
---|
723 | for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
|
---|
724 | if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
|
---|
725 | if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
|
---|
726 | && errno != ENOSYS)
|
---|
727 | goto error;
|
---|
728 | break;
|
---|
729 | }
|
---|
730 | done_mapping:
|
---|
731 | dso->base = base;
|
---|
732 | dso->dynv = laddr(dso, dyn);
|
---|
733 | if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
|
---|
734 | if (!runtime) reclaim_gaps(dso);
|
---|
735 | free(allocated_buf);
|
---|
736 | return map;
|
---|
737 | noexec:
|
---|
738 | errno = ENOEXEC;
|
---|
739 | error:
|
---|
740 | if (map!=MAP_FAILED) unmap_library(dso);
|
---|
741 | free(allocated_buf);
|
---|
742 | return 0;
|
---|
743 | }
|
---|
744 |
|
---|
745 | static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
|
---|
746 | {
|
---|
747 | size_t l;
|
---|
748 | int fd;
|
---|
749 | for (;;) {
|
---|
750 | s += strspn(s, ":\n");
|
---|
751 | l = strcspn(s, ":\n");
|
---|
752 | if (l-1 >= INT_MAX) return -1;
|
---|
753 | if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
|
---|
754 | if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
|
---|
755 | switch (errno) {
|
---|
756 | case ENOENT:
|
---|
757 | case ENOTDIR:
|
---|
758 | case EACCES:
|
---|
759 | case ENAMETOOLONG:
|
---|
760 | break;
|
---|
761 | default:
|
---|
762 | /* Any negative value but -1 will inhibit
|
---|
763 | * futher path search. */
|
---|
764 | return -2;
|
---|
765 | }
|
---|
766 | }
|
---|
767 | s += l;
|
---|
768 | }
|
---|
769 | }
|
---|
770 |
|
---|
771 | static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
|
---|
772 | {
|
---|
773 | size_t n, l;
|
---|
774 | const char *s, *t, *origin;
|
---|
775 | char *d;
|
---|
776 | if (p->rpath || !p->rpath_orig) return 0;
|
---|
777 | if (!strchr(p->rpath_orig, '$')) {
|
---|
778 | p->rpath = p->rpath_orig;
|
---|
779 | return 0;
|
---|
780 | }
|
---|
781 | n = 0;
|
---|
782 | s = p->rpath_orig;
|
---|
783 | while ((t=strchr(s, '$'))) {
|
---|
784 | if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
|
---|
785 | return 0;
|
---|
786 | s = t+1;
|
---|
787 | n++;
|
---|
788 | }
|
---|
789 | if (n > SSIZE_MAX/PATH_MAX) return 0;
|
---|
790 |
|
---|
791 | if (p->kernel_mapped) {
|
---|
792 | /* $ORIGIN searches cannot be performed for the main program
|
---|
793 | * when it is suid/sgid/AT_SECURE. This is because the
|
---|
794 | * pathname is under the control of the caller of execve.
|
---|
795 | * For libraries, however, $ORIGIN can be processed safely
|
---|
796 | * since the library's pathname came from a trusted source
|
---|
797 | * (either system paths or a call to dlopen). */
|
---|
798 | if (libc.secure)
|
---|
799 | return 0;
|
---|
800 | l = readlink("/proc/self/exe", buf, buf_size);
|
---|
801 | if (l == -1) switch (errno) {
|
---|
802 | case ENOENT:
|
---|
803 | case ENOTDIR:
|
---|
804 | case EACCES:
|
---|
805 | break;
|
---|
806 | default:
|
---|
807 | return -1;
|
---|
808 | }
|
---|
809 | if (l >= buf_size)
|
---|
810 | return 0;
|
---|
811 | buf[l] = 0;
|
---|
812 | origin = buf;
|
---|
813 | } else {
|
---|
814 | origin = p->name;
|
---|
815 | }
|
---|
816 | t = strrchr(origin, '/');
|
---|
817 | l = t ? t-origin : 0;
|
---|
818 | p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
|
---|
819 | if (!p->rpath) return -1;
|
---|
820 |
|
---|
821 | d = p->rpath;
|
---|
822 | s = p->rpath_orig;
|
---|
823 | while ((t=strchr(s, '$'))) {
|
---|
824 | memcpy(d, s, t-s);
|
---|
825 | d += t-s;
|
---|
826 | memcpy(d, origin, l);
|
---|
827 | d += l;
|
---|
828 | /* It was determined previously that the '$' is followed
|
---|
829 | * either by "ORIGIN" or "{ORIGIN}". */
|
---|
830 | s = t + 7 + 2*(t[1]=='{');
|
---|
831 | }
|
---|
832 | strcpy(d, s);
|
---|
833 | return 0;
|
---|
834 | }
|
---|
835 |
|
---|
836 | static void decode_dyn(struct dso *p)
|
---|
837 | {
|
---|
838 | size_t dyn[DYN_CNT];
|
---|
839 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
840 | p->syms = laddr(p, dyn[DT_SYMTAB]);
|
---|
841 | p->strings = laddr(p, dyn[DT_STRTAB]);
|
---|
842 | if (dyn[0]&(1<<DT_HASH))
|
---|
843 | p->hashtab = laddr(p, dyn[DT_HASH]);
|
---|
844 | if (dyn[0]&(1<<DT_RPATH))
|
---|
845 | p->rpath_orig = p->strings + dyn[DT_RPATH];
|
---|
846 | if (dyn[0]&(1<<DT_RUNPATH))
|
---|
847 | p->rpath_orig = p->strings + dyn[DT_RUNPATH];
|
---|
848 | if (dyn[0]&(1<<DT_PLTGOT))
|
---|
849 | p->got = laddr(p, dyn[DT_PLTGOT]);
|
---|
850 | if (search_vec(p->dynv, dyn, DT_GNU_HASH))
|
---|
851 | p->ghashtab = laddr(p, *dyn);
|
---|
852 | if (search_vec(p->dynv, dyn, DT_VERSYM))
|
---|
853 | p->versym = laddr(p, *dyn);
|
---|
854 | }
|
---|
855 |
|
---|
856 | static size_t count_syms(struct dso *p)
|
---|
857 | {
|
---|
858 | if (p->hashtab) return p->hashtab[1];
|
---|
859 |
|
---|
860 | size_t nsym, i;
|
---|
861 | uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
|
---|
862 | uint32_t *hashval;
|
---|
863 | for (i = nsym = 0; i < p->ghashtab[0]; i++) {
|
---|
864 | if (buckets[i] > nsym)
|
---|
865 | nsym = buckets[i];
|
---|
866 | }
|
---|
867 | if (nsym) {
|
---|
868 | hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
|
---|
869 | do nsym++;
|
---|
870 | while (!(*hashval++ & 1));
|
---|
871 | }
|
---|
872 | return nsym;
|
---|
873 | }
|
---|
874 |
|
---|
875 | static void *dl_mmap(size_t n)
|
---|
876 | {
|
---|
877 | void *p;
|
---|
878 | int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
|
---|
879 | #ifdef SYS_mmap2
|
---|
880 | p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
|
---|
881 | #else
|
---|
882 | p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
|
---|
883 | #endif
|
---|
884 | return p == MAP_FAILED ? 0 : p;
|
---|
885 | }
|
---|
886 |
|
---|
887 | static void makefuncdescs(struct dso *p)
|
---|
888 | {
|
---|
889 | static int self_done;
|
---|
890 | size_t nsym = count_syms(p);
|
---|
891 | size_t i, size = nsym * sizeof(*p->funcdescs);
|
---|
892 |
|
---|
893 | if (!self_done) {
|
---|
894 | p->funcdescs = dl_mmap(size);
|
---|
895 | self_done = 1;
|
---|
896 | } else {
|
---|
897 | p->funcdescs = malloc(size);
|
---|
898 | }
|
---|
899 | if (!p->funcdescs) {
|
---|
900 | if (!runtime) a_crash();
|
---|
901 | error("Error allocating function descriptors for %s", p->name);
|
---|
902 | longjmp(*rtld_fail, 1);
|
---|
903 | }
|
---|
904 | for (i=0; i<nsym; i++) {
|
---|
905 | if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
|
---|
906 | p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
|
---|
907 | p->funcdescs[i].got = p->got;
|
---|
908 | } else {
|
---|
909 | p->funcdescs[i].addr = 0;
|
---|
910 | p->funcdescs[i].got = 0;
|
---|
911 | }
|
---|
912 | }
|
---|
913 | }
|
---|
914 |
|
---|
915 | static struct dso *load_library(const char *name, struct dso *needed_by)
|
---|
916 | {
|
---|
917 | char buf[2*NAME_MAX+2];
|
---|
918 | const char *pathname;
|
---|
919 | unsigned char *map;
|
---|
920 | struct dso *p, temp_dso = {0};
|
---|
921 | int fd;
|
---|
922 | struct stat st;
|
---|
923 | size_t alloc_size;
|
---|
924 | int n_th = 0;
|
---|
925 | int is_self = 0;
|
---|
926 |
|
---|
927 | if (!*name) {
|
---|
928 | errno = EINVAL;
|
---|
929 | return 0;
|
---|
930 | }
|
---|
931 |
|
---|
932 | /* Catch and block attempts to reload the implementation itself */
|
---|
933 | if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
|
---|
934 | static const char reserved[] =
|
---|
935 | "c.pthread.rt.m.dl.util.xnet.";
|
---|
936 | const char *rp, *next;
|
---|
937 | for (rp=reserved; *rp; rp=next) {
|
---|
938 | next = strchr(rp, '.') + 1;
|
---|
939 | if (strncmp(name+3, rp, next-rp) == 0)
|
---|
940 | break;
|
---|
941 | }
|
---|
942 | if (*rp) {
|
---|
943 | if (ldd_mode) {
|
---|
944 | /* Track which names have been resolved
|
---|
945 | * and only report each one once. */
|
---|
946 | static unsigned reported;
|
---|
947 | unsigned mask = 1U<<(rp-reserved);
|
---|
948 | if (!(reported & mask)) {
|
---|
949 | reported |= mask;
|
---|
950 | dprintf(1, "\t%s => %s (%p)\n",
|
---|
951 | name, ldso.name,
|
---|
952 | ldso.base);
|
---|
953 | }
|
---|
954 | }
|
---|
955 | is_self = 1;
|
---|
956 | }
|
---|
957 | }
|
---|
958 | if (!strcmp(name, ldso.name)) is_self = 1;
|
---|
959 | if (is_self) {
|
---|
960 | if (!ldso.prev) {
|
---|
961 | tail->next = &ldso;
|
---|
962 | ldso.prev = tail;
|
---|
963 | tail = &ldso;
|
---|
964 | }
|
---|
965 | return &ldso;
|
---|
966 | }
|
---|
967 | if (strchr(name, '/')) {
|
---|
968 | pathname = name;
|
---|
969 | fd = open(name, O_RDONLY|O_CLOEXEC);
|
---|
970 | } else {
|
---|
971 | /* Search for the name to see if it's already loaded */
|
---|
972 | for (p=head->next; p; p=p->next) {
|
---|
973 | if (p->shortname && !strcmp(p->shortname, name)) {
|
---|
974 | return p;
|
---|
975 | }
|
---|
976 | }
|
---|
977 | if (strlen(name) > NAME_MAX) return 0;
|
---|
978 | fd = -1;
|
---|
979 | if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
|
---|
980 | for (p=needed_by; fd == -1 && p; p=p->needed_by) {
|
---|
981 | if (fixup_rpath(p, buf, sizeof buf) < 0)
|
---|
982 | fd = -2; /* Inhibit further search. */
|
---|
983 | if (p->rpath)
|
---|
984 | fd = path_open(name, p->rpath, buf, sizeof buf);
|
---|
985 | }
|
---|
986 | if (fd == -1) {
|
---|
987 | if (!sys_path) {
|
---|
988 | char *prefix = 0;
|
---|
989 | size_t prefix_len;
|
---|
990 | if (ldso.name[0]=='/') {
|
---|
991 | char *s, *t, *z;
|
---|
992 | for (s=t=z=ldso.name; *s; s++)
|
---|
993 | if (*s=='/') z=t, t=s;
|
---|
994 | prefix_len = z-ldso.name;
|
---|
995 | if (prefix_len < PATH_MAX)
|
---|
996 | prefix = ldso.name;
|
---|
997 | }
|
---|
998 | if (!prefix) {
|
---|
999 | prefix = "";
|
---|
1000 | prefix_len = 0;
|
---|
1001 | }
|
---|
1002 | char etc_ldso_path[prefix_len + 1
|
---|
1003 | + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
|
---|
1004 | snprintf(etc_ldso_path, sizeof etc_ldso_path,
|
---|
1005 | "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
|
---|
1006 | (int)prefix_len, prefix);
|
---|
1007 | FILE *f = fopen(etc_ldso_path, "rbe");
|
---|
1008 | if (f) {
|
---|
1009 | if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
|
---|
1010 | free(sys_path);
|
---|
1011 | sys_path = "";
|
---|
1012 | }
|
---|
1013 | fclose(f);
|
---|
1014 | } else if (errno != ENOENT) {
|
---|
1015 | sys_path = "";
|
---|
1016 | }
|
---|
1017 | }
|
---|
1018 | if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
|
---|
1019 | fd = path_open(name, sys_path, buf, sizeof buf);
|
---|
1020 | }
|
---|
1021 | pathname = buf;
|
---|
1022 | }
|
---|
1023 | if (fd < 0) return 0;
|
---|
1024 | if (fstat(fd, &st) < 0) {
|
---|
1025 | close(fd);
|
---|
1026 | return 0;
|
---|
1027 | }
|
---|
1028 | for (p=head->next; p; p=p->next) {
|
---|
1029 | if (p->dev == st.st_dev && p->ino == st.st_ino) {
|
---|
1030 | /* If this library was previously loaded with a
|
---|
1031 | * pathname but a search found the same inode,
|
---|
1032 | * setup its shortname so it can be found by name. */
|
---|
1033 | if (!p->shortname && pathname != name)
|
---|
1034 | p->shortname = strrchr(p->name, '/')+1;
|
---|
1035 | close(fd);
|
---|
1036 | return p;
|
---|
1037 | }
|
---|
1038 | }
|
---|
1039 | map = noload ? 0 : map_library(fd, &temp_dso);
|
---|
1040 | close(fd);
|
---|
1041 | if (!map) return 0;
|
---|
1042 |
|
---|
1043 | /* Avoid the danger of getting two versions of libc mapped into the
|
---|
1044 | * same process when an absolute pathname was used. The symbols
|
---|
1045 | * checked are chosen to catch both musl and glibc, and to avoid
|
---|
1046 | * false positives from interposition-hack libraries. */
|
---|
1047 | decode_dyn(&temp_dso);
|
---|
1048 | if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
|
---|
1049 | find_sym(&temp_dso, "stdin", 1).sym) {
|
---|
1050 | unmap_library(&temp_dso);
|
---|
1051 | return load_library("libc.so", needed_by);
|
---|
1052 | }
|
---|
1053 |
|
---|
1054 | /* Allocate storage for the new DSO. When there is TLS, this
|
---|
1055 | * storage must include a reservation for all pre-existing
|
---|
1056 | * threads to obtain copies of both the new TLS, and an
|
---|
1057 | * extended DTV capable of storing an additional slot for
|
---|
1058 | * the newly-loaded DSO. */
|
---|
1059 | alloc_size = sizeof *p + strlen(pathname) + 1;
|
---|
1060 | if (runtime && temp_dso.tls.image) {
|
---|
1061 | size_t per_th = temp_dso.tls.size + temp_dso.tls.align
|
---|
1062 | + sizeof(void *) * (tls_cnt+3);
|
---|
1063 | n_th = libc.threads_minus_1 + 1;
|
---|
1064 | if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
|
---|
1065 | else alloc_size += n_th * per_th;
|
---|
1066 | }
|
---|
1067 | p = calloc(1, alloc_size);
|
---|
1068 | if (!p) {
|
---|
1069 | unmap_library(&temp_dso);
|
---|
1070 | return 0;
|
---|
1071 | }
|
---|
1072 | memcpy(p, &temp_dso, sizeof temp_dso);
|
---|
1073 | p->dev = st.st_dev;
|
---|
1074 | p->ino = st.st_ino;
|
---|
1075 | p->needed_by = needed_by;
|
---|
1076 | p->name = p->buf;
|
---|
1077 | strcpy(p->name, pathname);
|
---|
1078 | /* Add a shortname only if name arg was not an explicit pathname. */
|
---|
1079 | if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
|
---|
1080 | if (p->tls.image) {
|
---|
1081 | p->tls_id = ++tls_cnt;
|
---|
1082 | tls_align = MAXP2(tls_align, p->tls.align);
|
---|
1083 | #ifdef TLS_ABOVE_TP
|
---|
1084 | p->tls.offset = tls_offset + ( (tls_align-1) &
|
---|
1085 | -(tls_offset + (uintptr_t)p->tls.image) );
|
---|
1086 | tls_offset += p->tls.size;
|
---|
1087 | #else
|
---|
1088 | tls_offset += p->tls.size + p->tls.align - 1;
|
---|
1089 | tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
|
---|
1090 | & (p->tls.align-1);
|
---|
1091 | p->tls.offset = tls_offset;
|
---|
1092 | #endif
|
---|
1093 | p->new_dtv = (void *)(-sizeof(size_t) &
|
---|
1094 | (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
|
---|
1095 | p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
|
---|
1096 | if (tls_tail) tls_tail->next = &p->tls;
|
---|
1097 | else libc.tls_head = &p->tls;
|
---|
1098 | tls_tail = &p->tls;
|
---|
1099 | }
|
---|
1100 |
|
---|
1101 | tail->next = p;
|
---|
1102 | p->prev = tail;
|
---|
1103 | tail = p;
|
---|
1104 |
|
---|
1105 | if (DL_FDPIC) makefuncdescs(p);
|
---|
1106 |
|
---|
1107 | if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
|
---|
1108 |
|
---|
1109 | return p;
|
---|
1110 | }
|
---|
1111 |
|
---|
1112 | static void load_deps(struct dso *p)
|
---|
1113 | {
|
---|
1114 | size_t i, ndeps=0;
|
---|
1115 | struct dso ***deps = &p->deps, **tmp, *dep;
|
---|
1116 | for (; p; p=p->next) {
|
---|
1117 | for (i=0; p->dynv[i]; i+=2) {
|
---|
1118 | if (p->dynv[i] != DT_NEEDED) continue;
|
---|
1119 | dep = load_library(p->strings + p->dynv[i+1], p);
|
---|
1120 | if (!dep) {
|
---|
1121 | error("Error loading shared library %s: %m (needed by %s)",
|
---|
1122 | p->strings + p->dynv[i+1], p->name);
|
---|
1123 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
1124 | continue;
|
---|
1125 | }
|
---|
1126 | if (runtime) {
|
---|
1127 | tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
|
---|
1128 | if (!tmp) longjmp(*rtld_fail, 1);
|
---|
1129 | tmp[ndeps++] = dep;
|
---|
1130 | tmp[ndeps] = 0;
|
---|
1131 | *deps = tmp;
|
---|
1132 | }
|
---|
1133 | }
|
---|
1134 | }
|
---|
1135 | if (!*deps) *deps = (struct dso **)&nodeps_dummy;
|
---|
1136 | }
|
---|
1137 |
|
---|
1138 | static void load_preload(char *s)
|
---|
1139 | {
|
---|
1140 | int tmp;
|
---|
1141 | char *z;
|
---|
1142 | for (z=s; *z; s=z) {
|
---|
1143 | for ( ; *s && (isspace(*s) || *s==':'); s++);
|
---|
1144 | for (z=s; *z && !isspace(*z) && *z!=':'; z++);
|
---|
1145 | tmp = *z;
|
---|
1146 | *z = 0;
|
---|
1147 | load_library(s, 0);
|
---|
1148 | *z = tmp;
|
---|
1149 | }
|
---|
1150 | }
|
---|
1151 |
|
---|
1152 | static void add_syms(struct dso *p)
|
---|
1153 | {
|
---|
1154 | if (!p->syms_next && syms_tail != p) {
|
---|
1155 | syms_tail->syms_next = p;
|
---|
1156 | syms_tail = p;
|
---|
1157 | }
|
---|
1158 | }
|
---|
1159 |
|
---|
1160 | static void revert_syms(struct dso *old_tail)
|
---|
1161 | {
|
---|
1162 | struct dso *p, *next;
|
---|
1163 | /* Chop off the tail of the list of dsos that participate in
|
---|
1164 | * the global symbol table, reverting them to RTLD_LOCAL. */
|
---|
1165 | for (p=old_tail; p; p=next) {
|
---|
1166 | next = p->syms_next;
|
---|
1167 | p->syms_next = 0;
|
---|
1168 | }
|
---|
1169 | syms_tail = old_tail;
|
---|
1170 | }
|
---|
1171 |
|
---|
1172 | static void do_mips_relocs(struct dso *p, size_t *got)
|
---|
1173 | {
|
---|
1174 | size_t i, j, rel[2];
|
---|
1175 | unsigned char *base = p->base;
|
---|
1176 | i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
|
---|
1177 | if (p==&ldso) {
|
---|
1178 | got += i;
|
---|
1179 | } else {
|
---|
1180 | while (i--) *got++ += (size_t)base;
|
---|
1181 | }
|
---|
1182 | j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
|
---|
1183 | i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
|
---|
1184 | Sym *sym = p->syms + j;
|
---|
1185 | rel[0] = (unsigned char *)got - base;
|
---|
1186 | for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
|
---|
1187 | rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
|
---|
1188 | do_relocs(p, rel, sizeof rel, 2);
|
---|
1189 | }
|
---|
1190 | }
|
---|
1191 |
|
---|
1192 | static void reloc_all(struct dso *p)
|
---|
1193 | {
|
---|
1194 | size_t dyn[DYN_CNT];
|
---|
1195 | for (; p; p=p->next) {
|
---|
1196 | if (p->relocated) continue;
|
---|
1197 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
1198 | if (NEED_MIPS_GOT_RELOCS)
|
---|
1199 | do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
|
---|
1200 | do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
|
---|
1201 | 2+(dyn[DT_PLTREL]==DT_RELA));
|
---|
1202 | do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
|
---|
1203 | do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
|
---|
1204 |
|
---|
1205 | if (head != &ldso && p->relro_start != p->relro_end &&
|
---|
1206 | mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
|
---|
1207 | && errno != ENOSYS) {
|
---|
1208 | error("Error relocating %s: RELRO protection failed: %m",
|
---|
1209 | p->name);
|
---|
1210 | if (runtime) longjmp(*rtld_fail, 1);
|
---|
1211 | }
|
---|
1212 |
|
---|
1213 | p->relocated = 1;
|
---|
1214 | }
|
---|
1215 | }
|
---|
1216 |
|
---|
1217 | static void kernel_mapped_dso(struct dso *p)
|
---|
1218 | {
|
---|
1219 | size_t min_addr = -1, max_addr = 0, cnt;
|
---|
1220 | Phdr *ph = p->phdr;
|
---|
1221 | for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
|
---|
1222 | if (ph->p_type == PT_DYNAMIC) {
|
---|
1223 | p->dynv = laddr(p, ph->p_vaddr);
|
---|
1224 | } else if (ph->p_type == PT_GNU_RELRO) {
|
---|
1225 | p->relro_start = ph->p_vaddr & -PAGE_SIZE;
|
---|
1226 | p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
|
---|
1227 | }
|
---|
1228 | if (ph->p_type != PT_LOAD) continue;
|
---|
1229 | if (ph->p_vaddr < min_addr)
|
---|
1230 | min_addr = ph->p_vaddr;
|
---|
1231 | if (ph->p_vaddr+ph->p_memsz > max_addr)
|
---|
1232 | max_addr = ph->p_vaddr+ph->p_memsz;
|
---|
1233 | }
|
---|
1234 | min_addr &= -PAGE_SIZE;
|
---|
1235 | max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
|
---|
1236 | p->map = p->base + min_addr;
|
---|
1237 | p->map_len = max_addr - min_addr;
|
---|
1238 | p->kernel_mapped = 1;
|
---|
1239 | }
|
---|
1240 |
|
---|
1241 | void __libc_exit_fini()
|
---|
1242 | {
|
---|
1243 | struct dso *p;
|
---|
1244 | size_t dyn[DYN_CNT];
|
---|
1245 | for (p=fini_head; p; p=p->fini_next) {
|
---|
1246 | if (!p->constructed) continue;
|
---|
1247 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
1248 | if (dyn[0] & (1<<DT_FINI_ARRAY)) {
|
---|
1249 | size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
|
---|
1250 | size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
|
---|
1251 | while (n--) ((void (*)(void))*--fn)();
|
---|
1252 | }
|
---|
1253 | #ifndef NO_LEGACY_INITFINI
|
---|
1254 | if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
|
---|
1255 | fpaddr(p, dyn[DT_FINI])();
|
---|
1256 | #endif
|
---|
1257 | }
|
---|
1258 | }
|
---|
1259 |
|
---|
1260 | static void do_init_fini(struct dso *p)
|
---|
1261 | {
|
---|
1262 | size_t dyn[DYN_CNT];
|
---|
1263 | int need_locking = libc.threads_minus_1;
|
---|
1264 | /* Allow recursive calls that arise when a library calls
|
---|
1265 | * dlopen from one of its constructors, but block any
|
---|
1266 | * other threads until all ctors have finished. */
|
---|
1267 | if (need_locking) pthread_mutex_lock(&init_fini_lock);
|
---|
1268 | for (; p; p=p->prev) {
|
---|
1269 | if (p->constructed) continue;
|
---|
1270 | p->constructed = 1;
|
---|
1271 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
1272 | if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
|
---|
1273 | p->fini_next = fini_head;
|
---|
1274 | fini_head = p;
|
---|
1275 | }
|
---|
1276 | #ifndef NO_LEGACY_INITFINI
|
---|
1277 | if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
|
---|
1278 | fpaddr(p, dyn[DT_INIT])();
|
---|
1279 | #endif
|
---|
1280 | if (dyn[0] & (1<<DT_INIT_ARRAY)) {
|
---|
1281 | size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
|
---|
1282 | size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
|
---|
1283 | while (n--) ((void (*)(void))*fn++)();
|
---|
1284 | }
|
---|
1285 | if (!need_locking && libc.threads_minus_1) {
|
---|
1286 | need_locking = 1;
|
---|
1287 | pthread_mutex_lock(&init_fini_lock);
|
---|
1288 | }
|
---|
1289 | }
|
---|
1290 | if (need_locking) pthread_mutex_unlock(&init_fini_lock);
|
---|
1291 | }
|
---|
1292 |
|
---|
1293 | #ifndef __c2__
|
---|
1294 | void __libc_start_init(void)
|
---|
1295 | {
|
---|
1296 | do_init_fini(tail);
|
---|
1297 | }
|
---|
1298 | #endif
|
---|
1299 |
|
---|
1300 | static void dl_debug_state(void)
|
---|
1301 | {
|
---|
1302 | }
|
---|
1303 |
|
---|
1304 | #ifndef __c2__
|
---|
1305 | weak_alias(dl_debug_state, _dl_debug_state);
|
---|
1306 |
|
---|
1307 | void __init_tls(size_t *auxv)
|
---|
1308 | {
|
---|
1309 | }
|
---|
1310 | #else
|
---|
1311 | __attribute__((weak))
|
---|
1312 | void _dl_debug_state(void)
|
---|
1313 | {
|
---|
1314 | dl_debug_state();
|
---|
1315 | }
|
---|
1316 | #endif
|
---|
1317 |
|
---|
1318 | __attribute__((__visibility__("hidden")))
|
---|
1319 | void *__tls_get_new(tls_mod_off_t *v)
|
---|
1320 | {
|
---|
1321 | pthread_t self = __pthread_self();
|
---|
1322 |
|
---|
1323 | /* Block signals to make accessing new TLS async-signal-safe */
|
---|
1324 | sigset_t set;
|
---|
1325 | __block_all_sigs(&set);
|
---|
1326 | if (v[0]<=(size_t)self->dtv[0]) {
|
---|
1327 | __restore_sigs(&set);
|
---|
1328 | return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
|
---|
1329 | }
|
---|
1330 |
|
---|
1331 | /* This is safe without any locks held because, if the caller
|
---|
1332 | * is able to request the Nth entry of the DTV, the DSO list
|
---|
1333 | * must be valid at least that far out and it was synchronized
|
---|
1334 | * at program startup or by an already-completed call to dlopen. */
|
---|
1335 | struct dso *p;
|
---|
1336 | for (p=head; p->tls_id != v[0]; p=p->next);
|
---|
1337 |
|
---|
1338 | /* Get new DTV space from new DSO if needed */
|
---|
1339 | if (v[0] > (size_t)self->dtv[0]) {
|
---|
1340 | void **newdtv = p->new_dtv +
|
---|
1341 | (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
|
---|
1342 | memcpy(newdtv, self->dtv,
|
---|
1343 | ((size_t)self->dtv[0]+1) * sizeof(void *));
|
---|
1344 | newdtv[0] = (void *)v[0];
|
---|
1345 | self->dtv = self->dtv_copy = newdtv;
|
---|
1346 | }
|
---|
1347 |
|
---|
1348 | /* Get new TLS memory from all new DSOs up to the requested one */
|
---|
1349 | unsigned char *mem;
|
---|
1350 | for (p=head; ; p=p->next) {
|
---|
1351 | if (!p->tls_id || self->dtv[p->tls_id]) continue;
|
---|
1352 | mem = p->new_tls + (p->tls.size + p->tls.align)
|
---|
1353 | * a_fetch_add(&p->new_tls_idx,1);
|
---|
1354 | mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
|
---|
1355 | & (p->tls.align-1);
|
---|
1356 | self->dtv[p->tls_id] = mem;
|
---|
1357 | memcpy(mem, p->tls.image, p->tls.len);
|
---|
1358 | if (p->tls_id == v[0]) break;
|
---|
1359 | }
|
---|
1360 | __restore_sigs(&set);
|
---|
1361 | return mem + v[1] + DTP_OFFSET;
|
---|
1362 | }
|
---|
1363 |
|
---|
1364 | static void update_tls_size()
|
---|
1365 | {
|
---|
1366 | libc.tls_cnt = tls_cnt;
|
---|
1367 | libc.tls_align = tls_align;
|
---|
1368 | libc.tls_size = ALIGN(
|
---|
1369 | (1+tls_cnt) * sizeof(void *) +
|
---|
1370 | tls_offset +
|
---|
1371 | sizeof(struct pthread) +
|
---|
1372 | tls_align * 2,
|
---|
1373 | tls_align);
|
---|
1374 | }
|
---|
1375 |
|
---|
1376 | /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
|
---|
1377 | * following stage 2 and stage 3 functions via primitive symbolic lookup
|
---|
1378 | * since it does not have access to their addresses to begin with. */
|
---|
1379 |
|
---|
1380 | /* Stage 2 of the dynamic linker is called after relative relocations
|
---|
1381 | * have been processed. It can make function calls to static functions
|
---|
1382 | * and access string literals and static data, but cannot use extern
|
---|
1383 | * symbols. Its job is to perform symbolic relocations on the dynamic
|
---|
1384 | * linker itself, but some of the relocations performed may need to be
|
---|
1385 | * replaced later due to copy relocations in the main program. */
|
---|
1386 |
|
---|
1387 | __attribute__((__visibility__("hidden")))
|
---|
1388 | void __dls2(unsigned char *base, size_t *sp)
|
---|
1389 | {
|
---|
1390 | if (DL_FDPIC) {
|
---|
1391 | void *p1 = (void *)sp[-2];
|
---|
1392 | void *p2 = (void *)sp[-1];
|
---|
1393 | if (!p1) {
|
---|
1394 | size_t *auxv, aux[AUX_CNT];
|
---|
1395 | for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
|
---|
1396 | decode_vec(auxv, aux, AUX_CNT);
|
---|
1397 | if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
|
---|
1398 | else ldso.base = (void *)(aux[AT_PHDR] & -4096);
|
---|
1399 | }
|
---|
1400 | app_loadmap = p2 ? p1 : 0;
|
---|
1401 | ldso.loadmap = p2 ? p2 : p1;
|
---|
1402 | ldso.base = laddr(&ldso, 0);
|
---|
1403 | } else {
|
---|
1404 | ldso.base = base;
|
---|
1405 | }
|
---|
1406 | Ehdr *ehdr = (void *)ldso.base;
|
---|
1407 | ldso.name = ldso.shortname = "libc.so";
|
---|
1408 | ldso.phnum = ehdr->e_phnum;
|
---|
1409 | ldso.phdr = laddr(&ldso, ehdr->e_phoff);
|
---|
1410 | ldso.phentsize = ehdr->e_phentsize;
|
---|
1411 | kernel_mapped_dso(&ldso);
|
---|
1412 | decode_dyn(&ldso);
|
---|
1413 |
|
---|
1414 | if (DL_FDPIC) makefuncdescs(&ldso);
|
---|
1415 |
|
---|
1416 | /* Prepare storage for to save clobbered REL addends so they
|
---|
1417 | * can be reused in stage 3. There should be very few. If
|
---|
1418 | * something goes wrong and there are a huge number, abort
|
---|
1419 | * instead of risking stack overflow. */
|
---|
1420 | size_t dyn[DYN_CNT];
|
---|
1421 | decode_vec(ldso.dynv, dyn, DYN_CNT);
|
---|
1422 | size_t *rel = laddr(&ldso, dyn[DT_REL]);
|
---|
1423 | size_t rel_size = dyn[DT_RELSZ];
|
---|
1424 | size_t symbolic_rel_cnt = 0;
|
---|
1425 | apply_addends_to = rel;
|
---|
1426 | for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
|
---|
1427 | if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
|
---|
1428 | if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
|
---|
1429 | size_t addends[symbolic_rel_cnt+1];
|
---|
1430 | saved_addends = addends;
|
---|
1431 |
|
---|
1432 | head = &ldso;
|
---|
1433 | reloc_all(&ldso);
|
---|
1434 |
|
---|
1435 | ldso.relocated = 0;
|
---|
1436 |
|
---|
1437 | /* Call dynamic linker stage-3, __dls3, looking it up
|
---|
1438 | * symbolically as a barrier against moving the address
|
---|
1439 | * load across the above relocation processing. */
|
---|
1440 | struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
|
---|
1441 | if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
|
---|
1442 | else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
|
---|
1443 | }
|
---|
1444 |
|
---|
1445 | /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
|
---|
1446 | * fully functional. Its job is to load (if not already loaded) and
|
---|
1447 | * process dependencies and relocations for the main application and
|
---|
1448 | * transfer control to its entry point. */
|
---|
1449 |
|
---|
1450 | _Noreturn void __dls3(size_t *sp)
|
---|
1451 | {
|
---|
1452 | static struct dso app, vdso;
|
---|
1453 | size_t aux[AUX_CNT], *auxv;
|
---|
1454 | size_t i;
|
---|
1455 | char *env_preload=0;
|
---|
1456 | char *replace_argv0=0;
|
---|
1457 | size_t vdso_base;
|
---|
1458 | int argc = *sp;
|
---|
1459 | char **argv = (void *)(sp+1);
|
---|
1460 | char **argv_orig = argv;
|
---|
1461 | char **envp = argv+argc+1;
|
---|
1462 |
|
---|
1463 | /* Find aux vector just past environ[] and use it to initialize
|
---|
1464 | * global data that may be needed before we can make syscalls. */
|
---|
1465 | __environ = envp;
|
---|
1466 | for (i=argc+1; argv[i]; i++);
|
---|
1467 | libc.auxv = auxv = (void *)(argv+i+1);
|
---|
1468 | decode_vec(auxv, aux, AUX_CNT);
|
---|
1469 | __hwcap = aux[AT_HWCAP];
|
---|
1470 | libc.page_size = aux[AT_PAGESZ];
|
---|
1471 | libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
|
---|
1472 | || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
|
---|
1473 |
|
---|
1474 | /* Setup early thread pointer in builtin_tls for ldso/libc itself to
|
---|
1475 | * use during dynamic linking. If possible it will also serve as the
|
---|
1476 | * thread pointer at runtime. */
|
---|
1477 | libc.tls_size = sizeof builtin_tls;
|
---|
1478 | libc.tls_align = tls_align;
|
---|
1479 | if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
|
---|
1480 | a_crash();
|
---|
1481 | }
|
---|
1482 |
|
---|
1483 | /* Only trust user/env if kernel says we're not suid/sgid */
|
---|
1484 | if (!libc.secure) {
|
---|
1485 | env_path = getenv("LD_LIBRARY_PATH");
|
---|
1486 | env_preload = getenv("LD_PRELOAD");
|
---|
1487 | }
|
---|
1488 |
|
---|
1489 | /* If the main program was already loaded by the kernel,
|
---|
1490 | * AT_PHDR will point to some location other than the dynamic
|
---|
1491 | * linker's program headers. */
|
---|
1492 | if (aux[AT_PHDR] != (size_t)ldso.phdr) {
|
---|
1493 | size_t interp_off = 0;
|
---|
1494 | size_t tls_image = 0;
|
---|
1495 | /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
|
---|
1496 | Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
|
---|
1497 | app.phnum = aux[AT_PHNUM];
|
---|
1498 | app.phentsize = aux[AT_PHENT];
|
---|
1499 | for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
|
---|
1500 | if (phdr->p_type == PT_PHDR)
|
---|
1501 | app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
|
---|
1502 | else if (phdr->p_type == PT_INTERP)
|
---|
1503 | interp_off = (size_t)phdr->p_vaddr;
|
---|
1504 | else if (phdr->p_type == PT_TLS) {
|
---|
1505 | tls_image = phdr->p_vaddr;
|
---|
1506 | app.tls.len = phdr->p_filesz;
|
---|
1507 | app.tls.size = phdr->p_memsz;
|
---|
1508 | app.tls.align = phdr->p_align;
|
---|
1509 | }
|
---|
1510 | }
|
---|
1511 | if (DL_FDPIC) app.loadmap = app_loadmap;
|
---|
1512 | if (app.tls.size) app.tls.image = laddr(&app, tls_image);
|
---|
1513 | if (interp_off) ldso.name = laddr(&app, interp_off);
|
---|
1514 | if ((aux[0] & (1UL<<AT_EXECFN))
|
---|
1515 | && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
|
---|
1516 | app.name = (char *)aux[AT_EXECFN];
|
---|
1517 | else
|
---|
1518 | app.name = argv[0];
|
---|
1519 | kernel_mapped_dso(&app);
|
---|
1520 | } else {
|
---|
1521 | int fd;
|
---|
1522 | char *ldname = argv[0];
|
---|
1523 | size_t l = strlen(ldname);
|
---|
1524 | if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
|
---|
1525 | argv++;
|
---|
1526 | while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
|
---|
1527 | char *opt = argv[0]+2;
|
---|
1528 | *argv++ = (void *)-1;
|
---|
1529 | if (!*opt) {
|
---|
1530 | break;
|
---|
1531 | } else if (!memcmp(opt, "list", 5)) {
|
---|
1532 | ldd_mode = 1;
|
---|
1533 | } else if (!memcmp(opt, "library-path", 12)) {
|
---|
1534 | if (opt[12]=='=') env_path = opt+13;
|
---|
1535 | else if (opt[12]) *argv = 0;
|
---|
1536 | else if (*argv) env_path = *argv++;
|
---|
1537 | } else if (!memcmp(opt, "preload", 7)) {
|
---|
1538 | if (opt[7]=='=') env_preload = opt+8;
|
---|
1539 | else if (opt[7]) *argv = 0;
|
---|
1540 | else if (*argv) env_preload = *argv++;
|
---|
1541 | } else if (!memcmp(opt, "argv0", 5)) {
|
---|
1542 | if (opt[5]=='=') replace_argv0 = opt+6;
|
---|
1543 | else if (opt[5]) *argv = 0;
|
---|
1544 | else if (*argv) replace_argv0 = *argv++;
|
---|
1545 | } else {
|
---|
1546 | argv[0] = 0;
|
---|
1547 | }
|
---|
1548 | }
|
---|
1549 | argv[-1] = (void *)(argc - (argv-argv_orig));
|
---|
1550 | if (!argv[0]) {
|
---|
1551 | dprintf(2, "musl libc (" LDSO_ARCH ")\n"
|
---|
1552 | "Version %s\n"
|
---|
1553 | "Dynamic Program Loader\n"
|
---|
1554 | "Usage: %s [options] [--] pathname%s\n",
|
---|
1555 | __libc_get_version(), ldname,
|
---|
1556 | ldd_mode ? "" : " [args]");
|
---|
1557 | _exit(1);
|
---|
1558 | }
|
---|
1559 | fd = open(argv[0], O_RDONLY);
|
---|
1560 | if (fd < 0) {
|
---|
1561 | dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
|
---|
1562 | _exit(1);
|
---|
1563 | }
|
---|
1564 | runtime = 1;
|
---|
1565 | Ehdr *ehdr = (void *)map_library(fd, &app);
|
---|
1566 | if (!ehdr) {
|
---|
1567 | dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
|
---|
1568 | _exit(1);
|
---|
1569 | }
|
---|
1570 | runtime = 0;
|
---|
1571 | close(fd);
|
---|
1572 | ldso.name = ldname;
|
---|
1573 | app.name = argv[0];
|
---|
1574 | aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
|
---|
1575 | /* Find the name that would have been used for the dynamic
|
---|
1576 | * linker had ldd not taken its place. */
|
---|
1577 | if (ldd_mode) {
|
---|
1578 | for (i=0; i<app.phnum; i++) {
|
---|
1579 | if (app.phdr[i].p_type == PT_INTERP)
|
---|
1580 | ldso.name = laddr(&app, app.phdr[i].p_vaddr);
|
---|
1581 | }
|
---|
1582 | dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
|
---|
1583 | }
|
---|
1584 | }
|
---|
1585 | if (app.tls.size) {
|
---|
1586 | libc.tls_head = tls_tail = &app.tls;
|
---|
1587 | app.tls_id = tls_cnt = 1;
|
---|
1588 | #ifdef TLS_ABOVE_TP
|
---|
1589 | app.tls.offset = 0;
|
---|
1590 | tls_offset = app.tls.size
|
---|
1591 | + ( -((uintptr_t)app.tls.image + app.tls.size)
|
---|
1592 | & (app.tls.align-1) );
|
---|
1593 | #else
|
---|
1594 | tls_offset = app.tls.offset = app.tls.size
|
---|
1595 | + ( -((uintptr_t)app.tls.image + app.tls.size)
|
---|
1596 | & (app.tls.align-1) );
|
---|
1597 | #endif
|
---|
1598 | tls_align = MAXP2(tls_align, app.tls.align);
|
---|
1599 | }
|
---|
1600 | decode_dyn(&app);
|
---|
1601 | if (DL_FDPIC) {
|
---|
1602 | makefuncdescs(&app);
|
---|
1603 | if (!app.loadmap) {
|
---|
1604 | app.loadmap = (void *)&app_dummy_loadmap;
|
---|
1605 | app.loadmap->nsegs = 1;
|
---|
1606 | app.loadmap->segs[0].addr = (size_t)app.map;
|
---|
1607 | app.loadmap->segs[0].p_vaddr = (size_t)app.map
|
---|
1608 | - (size_t)app.base;
|
---|
1609 | app.loadmap->segs[0].p_memsz = app.map_len;
|
---|
1610 | }
|
---|
1611 | argv[-3] = (void *)app.loadmap;
|
---|
1612 | }
|
---|
1613 |
|
---|
1614 | /* Initial dso chain consists only of the app. */
|
---|
1615 | head = tail = syms_tail = &app;
|
---|
1616 |
|
---|
1617 | /* Donate unused parts of app and library mapping to malloc */
|
---|
1618 | reclaim_gaps(&app);
|
---|
1619 | reclaim_gaps(&ldso);
|
---|
1620 |
|
---|
1621 | /* Load preload/needed libraries, add symbols to global namespace. */
|
---|
1622 | if (env_preload) load_preload(env_preload);
|
---|
1623 | load_deps(&app);
|
---|
1624 | for (struct dso *p=head; p; p=p->next)
|
---|
1625 | add_syms(p);
|
---|
1626 |
|
---|
1627 | /* Attach to vdso, if provided by the kernel, last so that it does
|
---|
1628 | * not become part of the global namespace. */
|
---|
1629 | if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
|
---|
1630 | Ehdr *ehdr = (void *)vdso_base;
|
---|
1631 | Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
|
---|
1632 | vdso.phnum = ehdr->e_phnum;
|
---|
1633 | vdso.phentsize = ehdr->e_phentsize;
|
---|
1634 | for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
|
---|
1635 | if (phdr->p_type == PT_DYNAMIC)
|
---|
1636 | vdso.dynv = (void *)(vdso_base + phdr->p_offset);
|
---|
1637 | if (phdr->p_type == PT_LOAD)
|
---|
1638 | vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
|
---|
1639 | }
|
---|
1640 | vdso.name = "";
|
---|
1641 | vdso.shortname = "linux-gate.so.1";
|
---|
1642 | vdso.relocated = 1;
|
---|
1643 | decode_dyn(&vdso);
|
---|
1644 | vdso.prev = tail;
|
---|
1645 | tail->next = &vdso;
|
---|
1646 | tail = &vdso;
|
---|
1647 | }
|
---|
1648 |
|
---|
1649 | for (i=0; app.dynv[i]; i+=2) {
|
---|
1650 | if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
|
---|
1651 | app.dynv[i+1] = (size_t)&debug;
|
---|
1652 | if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
|
---|
1653 | size_t *ptr = (size_t *) app.dynv[i+1];
|
---|
1654 | *ptr = (size_t)&debug;
|
---|
1655 | }
|
---|
1656 | }
|
---|
1657 |
|
---|
1658 | /* The main program must be relocated LAST since it may contin
|
---|
1659 | * copy relocations which depend on libraries' relocations. */
|
---|
1660 | reloc_all(app.next);
|
---|
1661 | reloc_all(&app);
|
---|
1662 |
|
---|
1663 | update_tls_size();
|
---|
1664 | if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
|
---|
1665 | void *initial_tls = calloc(libc.tls_size, 1);
|
---|
1666 | if (!initial_tls) {
|
---|
1667 | dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
|
---|
1668 | argv[0], libc.tls_size);
|
---|
1669 | _exit(127);
|
---|
1670 | }
|
---|
1671 | if (__init_tp(__copy_tls(initial_tls)) < 0) {
|
---|
1672 | a_crash();
|
---|
1673 | }
|
---|
1674 | } else {
|
---|
1675 | size_t tmp_tls_size = libc.tls_size;
|
---|
1676 | pthread_t self = __pthread_self();
|
---|
1677 | /* Temporarily set the tls size to the full size of
|
---|
1678 | * builtin_tls so that __copy_tls will use the same layout
|
---|
1679 | * as it did for before. Then check, just to be safe. */
|
---|
1680 | libc.tls_size = sizeof builtin_tls;
|
---|
1681 | if (__copy_tls((void*)builtin_tls) != self) a_crash();
|
---|
1682 | libc.tls_size = tmp_tls_size;
|
---|
1683 | }
|
---|
1684 | static_tls_cnt = tls_cnt;
|
---|
1685 |
|
---|
1686 | if (ldso_fail) _exit(127);
|
---|
1687 | if (ldd_mode) _exit(0);
|
---|
1688 |
|
---|
1689 | /* Switch to runtime mode: any further failures in the dynamic
|
---|
1690 | * linker are a reportable failure rather than a fatal startup
|
---|
1691 | * error. */
|
---|
1692 | runtime = 1;
|
---|
1693 |
|
---|
1694 | debug.ver = 1;
|
---|
1695 | debug.bp = dl_debug_state;
|
---|
1696 | debug.head = head;
|
---|
1697 | debug.base = ldso.base;
|
---|
1698 | debug.state = 0;
|
---|
1699 | _dl_debug_state();
|
---|
1700 |
|
---|
1701 | if (replace_argv0) argv[0] = replace_argv0;
|
---|
1702 |
|
---|
1703 | errno = 0;
|
---|
1704 |
|
---|
1705 | CRTJMP((void *)aux[AT_ENTRY], argv-1);
|
---|
1706 | for(;;);
|
---|
1707 | }
|
---|
1708 |
|
---|
1709 | static void prepare_lazy(struct dso *p)
|
---|
1710 | {
|
---|
1711 | size_t dyn[DYN_CNT], n, flags1=0;
|
---|
1712 | decode_vec(p->dynv, dyn, DYN_CNT);
|
---|
1713 | search_vec(p->dynv, &flags1, DT_FLAGS_1);
|
---|
1714 | if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
|
---|
1715 | return;
|
---|
1716 | n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
|
---|
1717 | if (NEED_MIPS_GOT_RELOCS) {
|
---|
1718 | size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
|
---|
1719 | size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
|
---|
1720 | n += i-j;
|
---|
1721 | }
|
---|
1722 | p->lazy = calloc(n, 3*sizeof(size_t));
|
---|
1723 | if (!p->lazy) {
|
---|
1724 | error("Error preparing lazy relocation for %s: %m", p->name);
|
---|
1725 | longjmp(*rtld_fail, 1);
|
---|
1726 | }
|
---|
1727 | p->lazy_next = lazy_head;
|
---|
1728 | lazy_head = p;
|
---|
1729 | }
|
---|
1730 |
|
---|
1731 | void *dlopen(const char *file, int mode)
|
---|
1732 | {
|
---|
1733 | struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
|
---|
1734 | struct tls_module *orig_tls_tail;
|
---|
1735 | size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
|
---|
1736 | size_t i;
|
---|
1737 | int cs;
|
---|
1738 | jmp_buf jb;
|
---|
1739 |
|
---|
1740 | if (!file) return head;
|
---|
1741 |
|
---|
1742 | pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
|
---|
1743 | pthread_rwlock_wrlock(&lock);
|
---|
1744 | __inhibit_ptc();
|
---|
1745 |
|
---|
1746 | p = 0;
|
---|
1747 | orig_tls_tail = tls_tail;
|
---|
1748 | orig_tls_cnt = tls_cnt;
|
---|
1749 | orig_tls_offset = tls_offset;
|
---|
1750 | orig_tls_align = tls_align;
|
---|
1751 | orig_lazy_head = lazy_head;
|
---|
1752 | orig_syms_tail = syms_tail;
|
---|
1753 | orig_tail = tail;
|
---|
1754 | noload = mode & RTLD_NOLOAD;
|
---|
1755 |
|
---|
1756 | rtld_fail = &jb;
|
---|
1757 | if (setjmp(*rtld_fail)) {
|
---|
1758 | /* Clean up anything new that was (partially) loaded */
|
---|
1759 | revert_syms(orig_syms_tail);
|
---|
1760 | for (p=orig_tail->next; p; p=next) {
|
---|
1761 | next = p->next;
|
---|
1762 | while (p->td_index) {
|
---|
1763 | void *tmp = p->td_index->next;
|
---|
1764 | free(p->td_index);
|
---|
1765 | p->td_index = tmp;
|
---|
1766 | }
|
---|
1767 | free(p->funcdescs);
|
---|
1768 | if (p->rpath != p->rpath_orig)
|
---|
1769 | free(p->rpath);
|
---|
1770 | if (p->deps != &nodeps_dummy)
|
---|
1771 | free(p->deps);
|
---|
1772 | unmap_library(p);
|
---|
1773 | free(p);
|
---|
1774 | }
|
---|
1775 | if (!orig_tls_tail) libc.tls_head = 0;
|
---|
1776 | tls_tail = orig_tls_tail;
|
---|
1777 | if (tls_tail) tls_tail->next = 0;
|
---|
1778 | tls_cnt = orig_tls_cnt;
|
---|
1779 | tls_offset = orig_tls_offset;
|
---|
1780 | tls_align = orig_tls_align;
|
---|
1781 | lazy_head = orig_lazy_head;
|
---|
1782 | tail = orig_tail;
|
---|
1783 | tail->next = 0;
|
---|
1784 | p = 0;
|
---|
1785 | goto end;
|
---|
1786 | } else p = load_library(file, head);
|
---|
1787 |
|
---|
1788 | if (!p) {
|
---|
1789 | error(noload ?
|
---|
1790 | "Library %s is not already loaded" :
|
---|
1791 | "Error loading shared library %s: %m",
|
---|
1792 | file);
|
---|
1793 | goto end;
|
---|
1794 | }
|
---|
1795 |
|
---|
1796 | /* First load handling */
|
---|
1797 | int first_load = !p->deps;
|
---|
1798 | if (first_load) {
|
---|
1799 | load_deps(p);
|
---|
1800 | if (!p->relocated && (mode & RTLD_LAZY)) {
|
---|
1801 | prepare_lazy(p);
|
---|
1802 | for (i=0; p->deps[i]; i++)
|
---|
1803 | if (!p->deps[i]->relocated)
|
---|
1804 | prepare_lazy(p->deps[i]);
|
---|
1805 | }
|
---|
1806 | }
|
---|
1807 | if (first_load || (mode & RTLD_GLOBAL)) {
|
---|
1808 | /* Make new symbols global, at least temporarily, so we can do
|
---|
1809 | * relocations. If not RTLD_GLOBAL, this is reverted below. */
|
---|
1810 | add_syms(p);
|
---|
1811 | for (i=0; p->deps[i]; i++)
|
---|
1812 | add_syms(p->deps[i]);
|
---|
1813 | }
|
---|
1814 | if (first_load) {
|
---|
1815 | reloc_all(p);
|
---|
1816 | }
|
---|
1817 |
|
---|
1818 | /* If RTLD_GLOBAL was not specified, undo any new additions
|
---|
1819 | * to the global symbol table. This is a nop if the library was
|
---|
1820 | * previously loaded and already global. */
|
---|
1821 | if (!(mode & RTLD_GLOBAL))
|
---|
1822 | revert_syms(orig_syms_tail);
|
---|
1823 |
|
---|
1824 | /* Processing of deferred lazy relocations must not happen until
|
---|
1825 | * the new libraries are committed; otherwise we could end up with
|
---|
1826 | * relocations resolved to symbol definitions that get removed. */
|
---|
1827 | redo_lazy_relocs();
|
---|
1828 |
|
---|
1829 | update_tls_size();
|
---|
1830 | _dl_debug_state();
|
---|
1831 | orig_tail = tail;
|
---|
1832 | end:
|
---|
1833 | __release_ptc();
|
---|
1834 | if (p) gencnt++;
|
---|
1835 | pthread_rwlock_unlock(&lock);
|
---|
1836 | if (p) do_init_fini(orig_tail);
|
---|
1837 | pthread_setcancelstate(cs, 0);
|
---|
1838 | return p;
|
---|
1839 | }
|
---|
1840 |
|
---|
1841 | __attribute__((__visibility__("hidden")))
|
---|
1842 | int __dl_invalid_handle(void *h)
|
---|
1843 | {
|
---|
1844 | struct dso *p;
|
---|
1845 | for (p=head; p; p=p->next) if (h==p) return 0;
|
---|
1846 | error("Invalid library handle %p", (void *)h);
|
---|
1847 | return 1;
|
---|
1848 | }
|
---|
1849 |
|
---|
1850 | static void *addr2dso(size_t a)
|
---|
1851 | {
|
---|
1852 | struct dso *p;
|
---|
1853 | size_t i;
|
---|
1854 | if (DL_FDPIC) for (p=head; p; p=p->next) {
|
---|
1855 | i = count_syms(p);
|
---|
1856 | if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
|
---|
1857 | return p;
|
---|
1858 | }
|
---|
1859 | for (p=head; p; p=p->next) {
|
---|
1860 | if (DL_FDPIC && p->loadmap) {
|
---|
1861 | for (i=0; i<p->loadmap->nsegs; i++) {
|
---|
1862 | if (a-p->loadmap->segs[i].p_vaddr
|
---|
1863 | < p->loadmap->segs[i].p_memsz)
|
---|
1864 | return p;
|
---|
1865 | }
|
---|
1866 | } else {
|
---|
1867 | if (a-(size_t)p->map < p->map_len)
|
---|
1868 | return p;
|
---|
1869 | }
|
---|
1870 | }
|
---|
1871 | return 0;
|
---|
1872 | }
|
---|
1873 |
|
---|
1874 | void *__tls_get_addr(tls_mod_off_t *);
|
---|
1875 |
|
---|
1876 | static void *do_dlsym(struct dso *p, const char *s, void *ra)
|
---|
1877 | {
|
---|
1878 | size_t i;
|
---|
1879 | uint32_t h = 0, gh = 0, *ght;
|
---|
1880 | Sym *sym;
|
---|
1881 | if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
|
---|
1882 | if (p == RTLD_DEFAULT) {
|
---|
1883 | p = head;
|
---|
1884 | } else if (p == RTLD_NEXT) {
|
---|
1885 | p = addr2dso((size_t)ra);
|
---|
1886 | if (!p) p=head;
|
---|
1887 | p = p->next;
|
---|
1888 | }
|
---|
1889 | struct symdef def = find_sym(p, s, 0);
|
---|
1890 | if (!def.sym) goto failed;
|
---|
1891 | if ((def.sym->st_info&0xf) == STT_TLS)
|
---|
1892 | return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
|
---|
1893 | if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
|
---|
1894 | return def.dso->funcdescs + (def.sym - def.dso->syms);
|
---|
1895 | return laddr(def.dso, def.sym->st_value);
|
---|
1896 | }
|
---|
1897 | if (__dl_invalid_handle(p))
|
---|
1898 | return 0;
|
---|
1899 | if ((ght = p->ghashtab)) {
|
---|
1900 | gh = gnu_hash(s);
|
---|
1901 | sym = gnu_lookup(gh, ght, p, s);
|
---|
1902 | } else {
|
---|
1903 | h = sysv_hash(s);
|
---|
1904 | sym = sysv_lookup(s, h, p);
|
---|
1905 | }
|
---|
1906 | if (sym && (sym->st_info&0xf) == STT_TLS)
|
---|
1907 | return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
|
---|
1908 | if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
|
---|
1909 | return p->funcdescs + (sym - p->syms);
|
---|
1910 | if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
|
---|
1911 | return laddr(p, sym->st_value);
|
---|
1912 | for (i=0; p->deps[i]; i++) {
|
---|
1913 | if ((ght = p->deps[i]->ghashtab)) {
|
---|
1914 | if (!gh) gh = gnu_hash(s);
|
---|
1915 | sym = gnu_lookup(gh, ght, p->deps[i], s);
|
---|
1916 | } else {
|
---|
1917 | if (!h) h = sysv_hash(s);
|
---|
1918 | sym = sysv_lookup(s, h, p->deps[i]);
|
---|
1919 | }
|
---|
1920 | if (sym && (sym->st_info&0xf) == STT_TLS)
|
---|
1921 | return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
|
---|
1922 | if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
|
---|
1923 | return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
|
---|
1924 | if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
|
---|
1925 | return laddr(p->deps[i], sym->st_value);
|
---|
1926 | }
|
---|
1927 | failed:
|
---|
1928 | error("Symbol not found: %s", s);
|
---|
1929 | return 0;
|
---|
1930 | }
|
---|
1931 |
|
---|
1932 | int dladdr(const void *addr, Dl_info *info)
|
---|
1933 | {
|
---|
1934 | struct dso *p;
|
---|
1935 | Sym *sym, *bestsym;
|
---|
1936 | uint32_t nsym;
|
---|
1937 | char *strings;
|
---|
1938 | void *best = 0;
|
---|
1939 |
|
---|
1940 | pthread_rwlock_rdlock(&lock);
|
---|
1941 | p = addr2dso((size_t)addr);
|
---|
1942 | pthread_rwlock_unlock(&lock);
|
---|
1943 |
|
---|
1944 | if (!p) return 0;
|
---|
1945 |
|
---|
1946 | sym = p->syms;
|
---|
1947 | strings = p->strings;
|
---|
1948 | nsym = count_syms(p);
|
---|
1949 |
|
---|
1950 | if (DL_FDPIC) {
|
---|
1951 | size_t idx = ((size_t)addr-(size_t)p->funcdescs)
|
---|
1952 | / sizeof(*p->funcdescs);
|
---|
1953 | if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
|
---|
1954 | best = p->funcdescs + idx;
|
---|
1955 | bestsym = sym + idx;
|
---|
1956 | }
|
---|
1957 | }
|
---|
1958 |
|
---|
1959 | if (!best) for (; nsym; nsym--, sym++) {
|
---|
1960 | if (sym->st_value
|
---|
1961 | && (1<<(sym->st_info&0xf) & OK_TYPES)
|
---|
1962 | && (1<<(sym->st_info>>4) & OK_BINDS)) {
|
---|
1963 | void *symaddr = laddr(p, sym->st_value);
|
---|
1964 | if (symaddr > addr || symaddr < best)
|
---|
1965 | continue;
|
---|
1966 | best = symaddr;
|
---|
1967 | bestsym = sym;
|
---|
1968 | if (addr == symaddr)
|
---|
1969 | break;
|
---|
1970 | }
|
---|
1971 | }
|
---|
1972 |
|
---|
1973 | if (!best) return 0;
|
---|
1974 |
|
---|
1975 | if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
|
---|
1976 | best = p->funcdescs + (bestsym - p->syms);
|
---|
1977 |
|
---|
1978 | info->dli_fname = p->name;
|
---|
1979 | info->dli_fbase = p->base;
|
---|
1980 | info->dli_sname = strings + bestsym->st_name;
|
---|
1981 | info->dli_saddr = best;
|
---|
1982 |
|
---|
1983 | return 1;
|
---|
1984 | }
|
---|
1985 |
|
---|
1986 | __attribute__((__visibility__("hidden")))
|
---|
1987 | void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
|
---|
1988 | {
|
---|
1989 | void *res;
|
---|
1990 | pthread_rwlock_rdlock(&lock);
|
---|
1991 | res = do_dlsym(p, s, ra);
|
---|
1992 | pthread_rwlock_unlock(&lock);
|
---|
1993 | return res;
|
---|
1994 | }
|
---|
1995 |
|
---|
1996 | int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
|
---|
1997 | {
|
---|
1998 | struct dso *current;
|
---|
1999 | struct dl_phdr_info info;
|
---|
2000 | int ret = 0;
|
---|
2001 | for(current = head; current;) {
|
---|
2002 | info.dlpi_addr = (uintptr_t)current->base;
|
---|
2003 | info.dlpi_name = current->name;
|
---|
2004 | info.dlpi_phdr = current->phdr;
|
---|
2005 | info.dlpi_phnum = current->phnum;
|
---|
2006 | info.dlpi_adds = gencnt;
|
---|
2007 | info.dlpi_subs = 0;
|
---|
2008 | info.dlpi_tls_modid = current->tls_id;
|
---|
2009 | info.dlpi_tls_data = current->tls.image;
|
---|
2010 |
|
---|
2011 | ret = (callback)(&info, sizeof (info), data);
|
---|
2012 |
|
---|
2013 | if (ret != 0) break;
|
---|
2014 |
|
---|
2015 | pthread_rwlock_rdlock(&lock);
|
---|
2016 | current = current->next;
|
---|
2017 | pthread_rwlock_unlock(&lock);
|
---|
2018 | }
|
---|
2019 | return ret;
|
---|
2020 | }
|
---|
2021 |
|
---|
2022 | __attribute__((__visibility__("hidden")))
|
---|
2023 | void __dl_vseterr(const char *, va_list);
|
---|
2024 |
|
---|
2025 | static void error(const char *fmt, ...)
|
---|
2026 | {
|
---|
2027 | va_list ap;
|
---|
2028 | va_start(ap, fmt);
|
---|
2029 | if (!runtime) {
|
---|
2030 | vdprintf(2, fmt, ap);
|
---|
2031 | dprintf(2, "\n");
|
---|
2032 | ldso_fail = 1;
|
---|
2033 | va_end(ap);
|
---|
2034 | return;
|
---|
2035 | }
|
---|
2036 | __dl_vseterr(fmt, ap);
|
---|
2037 | va_end(ap);
|
---|
2038 | }
|
---|