blob: 42b056d2f264aef11978ebf5ebeb8e48523dde69 [file] [log] [blame]
Rich Felkerf419bcb2012-08-26 21:09:26 -04001#define _GNU_SOURCE
Rich Felker51e2d832011-06-18 19:48:42 -04002#include <stdio.h>
3#include <stdlib.h>
Rich Felker7c73cac2014-06-18 03:05:42 -04004#include <stdarg.h>
Rich Felker9d15d5e2014-06-19 02:01:06 -04005#include <stddef.h>
Rich Felker51e2d832011-06-18 19:48:42 -04006#include <string.h>
7#include <unistd.h>
8#include <stdint.h>
9#include <elf.h>
10#include <sys/mman.h>
11#include <limits.h>
Rich Felker51e2d832011-06-18 19:48:42 -040012#include <fcntl.h>
13#include <sys/stat.h>
14#include <errno.h>
Rich Felker18c0e022012-10-31 21:27:48 -040015#include <link.h>
Rich Felker6b3d5e52011-06-26 17:39:17 -040016#include <setjmp.h>
Rich Felker59ab43f2011-06-26 19:23:28 -040017#include <pthread.h>
Rich Felker2719cc82011-08-16 00:24:36 -040018#include <ctype.h>
Rich Felker59ab43f2011-06-26 19:23:28 -040019#include <dlfcn.h>
Rich Felker8431d792012-10-04 16:35:46 -040020#include "pthread_impl.h"
21#include "libc.h"
Rich Felkerf3ddd172015-04-13 02:56:26 -040022#include "dynlink.h"
Rich Felker51e2d832011-06-18 19:48:42 -040023
Rich Felker01d42742015-04-18 18:00:22 -040024static void error(const char *, ...);
Rich Felkera9e85c02012-03-23 00:28:20 -040025
Rich Felkere864a292012-07-11 01:47:30 -040026#ifdef SHARED
Rich Felkera9e85c02012-03-23 00:28:20 -040027
Rich Felkercf3fd3d2012-10-06 01:22:51 -040028#define MAXP2(a,b) (-(-(a)&-(b)))
29#define ALIGN(x,y) ((x)+(y)-1 & -(y))
30
Rich Felker3ec8d292012-04-25 00:05:42 -040031struct debug {
32 int ver;
33 void *head;
34 void (*bp)(void);
35 int state;
36 void *base;
37};
38
Rich Felker9d15d5e2014-06-19 02:01:06 -040039struct td_index {
40 size_t args[2];
41 struct td_index *next;
42};
43
Rich Felker3ec8d292012-04-25 00:05:42 -040044struct dso {
45 unsigned char *base;
46 char *name;
Rich Felker51e2d832011-06-18 19:48:42 -040047 size_t *dynv;
Rich Felker3ec8d292012-04-25 00:05:42 -040048 struct dso *next, *prev;
49
Rich Felker18c0e022012-10-31 21:27:48 -040050 Phdr *phdr;
51 int phnum;
Timo Teräs87691962014-03-25 20:59:50 +020052 size_t phentsize;
Rich Felker3ec8d292012-04-25 00:05:42 -040053 int refcnt;
Rich Felker51e2d832011-06-18 19:48:42 -040054 Sym *syms;
Rich Felker596d60c2011-06-18 22:52:01 -040055 uint32_t *hashtab;
Rich Felker2bd05a42012-08-25 17:13:28 -040056 uint32_t *ghashtab;
Rich Felker72482f92013-08-08 16:10:35 -040057 int16_t *versym;
Rich Felker51e2d832011-06-18 19:48:42 -040058 char *strings;
Rich Felker51e2d832011-06-18 19:48:42 -040059 unsigned char *map;
60 size_t map_len;
61 dev_t dev;
62 ino_t ino;
Rich Felker6343ac82012-06-09 21:20:44 -040063 signed char global;
Rich Felker700a8152012-02-07 20:29:29 -050064 char relocated;
65 char constructed;
Rich Felkera897a202013-08-23 13:56:30 -040066 char kernel_mapped;
Rich Felker709355e2013-08-23 11:15:40 -040067 struct dso **deps, *needed_by;
Rich Felkera897a202013-08-23 13:56:30 -040068 char *rpath_orig, *rpath;
Rich Felkerbc6a35f2012-10-04 20:04:13 -040069 void *tls_image;
Rich Felker9c748562012-10-04 22:48:33 -040070 size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
Timo Teräse13a2b82014-03-25 14:13:27 +020071 size_t relro_start, relro_end;
Rich Felkerdcd60372012-10-05 11:51:50 -040072 void **new_dtv;
73 unsigned char *new_tls;
Rich Felker56fbaa32015-03-03 22:50:02 -050074 volatile int new_dtv_idx, new_tls_idx;
Rich Felker9d15d5e2014-06-19 02:01:06 -040075 struct td_index *td_index;
Rich Felkerf4f77c02012-10-05 13:09:09 -040076 struct dso *fini_next;
Rich Felker5c1909a2012-05-27 16:01:44 -040077 char *shortname;
Rich Felker6b3d5e52011-06-26 17:39:17 -040078 char buf[];
Rich Felker51e2d832011-06-18 19:48:42 -040079};
80
Rich Felker9c748562012-10-04 22:48:33 -040081struct symdef {
82 Sym *sym;
83 struct dso *dso;
84};
85
Rich Felkerdab441a2014-03-24 16:57:11 -040086int __init_tp(void *);
Rich Felker75863602013-07-21 03:00:54 -040087void __init_libc(char **, char *);
Rich Felker60872cf2012-04-24 18:07:59 -040088
Rich Felker179ab5a2013-12-01 17:27:25 -050089const char *__libc_get_version(void);
90
Rich Felkerbd679592015-03-06 13:27:08 -050091static struct builtin_tls {
92 char c;
93 struct pthread pt;
94 void *space[16];
95} builtin_tls[1];
96#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
97
Rich Felker9bbddf72015-05-25 23:33:59 -040098#define ADDEND_LIMIT 4096
99static size_t *saved_addends, *apply_addends_to;
100
Rich Felkerf3ddd172015-04-13 02:56:26 -0400101static struct dso ldso;
102static struct dso *head, *tail, *fini_head;
Rich Felker709355e2013-08-23 11:15:40 -0400103static char *env_path, *sys_path;
Rich Felker18c0e022012-10-31 21:27:48 -0400104static unsigned long long gencnt;
Rich Felker6b3d5e52011-06-26 17:39:17 -0400105static int runtime;
Rich Felker5c1909a2012-05-27 16:01:44 -0400106static int ldd_mode;
Rich Felker04109502012-08-18 16:00:23 -0400107static int ldso_fail;
Rich Felker4d07e552013-01-23 22:07:45 -0500108static int noload;
Rich Felker17276be2013-07-24 02:38:05 -0400109static jmp_buf *rtld_fail;
Rich Felker59ab43f2011-06-26 19:23:28 -0400110static pthread_rwlock_t lock;
Rich Felker3ec8d292012-04-25 00:05:42 -0400111static struct debug debug;
Rich Felkerbd679592015-03-06 13:27:08 -0500112static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
Rich Felker9d15d5e2014-06-19 02:01:06 -0400113static size_t static_tls_cnt;
Rich Felkerf4f77c02012-10-05 13:09:09 -0400114static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
Rich Felker3ec8d292012-04-25 00:05:42 -0400115
116struct debug *_dl_debug_addr = &debug;
Rich Felker51e2d832011-06-18 19:48:42 -0400117
Rich Felkerf3ddd172015-04-13 02:56:26 -0400118static int dl_strcmp(const char *l, const char *r)
119{
120 for (; *l==*r && *l; l++, r++);
121 return *(unsigned char *)l - *(unsigned char *)r;
122}
123#define strcmp(l,r) dl_strcmp(l,r)
Rich Felker51e2d832011-06-18 19:48:42 -0400124
125static void decode_vec(size_t *v, size_t *a, size_t cnt)
126{
Rich Felkerf3ddd172015-04-13 02:56:26 -0400127 size_t i;
128 for (i=0; i<cnt; i++) a[i] = 0;
129 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
130 a[0] |= 1UL<<v[0];
Rich Felker51e2d832011-06-18 19:48:42 -0400131 a[v[0]] = v[1];
132 }
133}
134
Rich Felker2bd05a42012-08-25 17:13:28 -0400135static int search_vec(size_t *v, size_t *r, size_t key)
136{
137 for (; v[0]!=key; v+=2)
138 if (!v[0]) return 0;
139 *r = v[1];
140 return 1;
141}
142
143static uint32_t sysv_hash(const char *s0)
Rich Felker51e2d832011-06-18 19:48:42 -0400144{
Rich Felker2adf2fb2012-01-17 00:34:58 -0500145 const unsigned char *s = (void *)s0;
Rich Felker51e2d832011-06-18 19:48:42 -0400146 uint_fast32_t h = 0;
147 while (*s) {
148 h = 16*h + *s++;
149 h ^= h>>24 & 0xf0;
150 }
151 return h & 0xfffffff;
152}
153
Rich Felker2bd05a42012-08-25 17:13:28 -0400154static uint32_t gnu_hash(const char *s0)
155{
156 const unsigned char *s = (void *)s0;
157 uint_fast32_t h = 5381;
158 for (; *s; s++)
159 h = h*33 + *s;
160 return h;
161}
162
163static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
Rich Felker51e2d832011-06-18 19:48:42 -0400164{
165 size_t i;
Rich Felker05eff012012-08-05 02:38:35 -0400166 Sym *syms = dso->syms;
167 uint32_t *hashtab = dso->hashtab;
168 char *strings = dso->strings;
Rich Felker51e2d832011-06-18 19:48:42 -0400169 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
Rich Felker72482f92013-08-08 16:10:35 -0400170 if ((!dso->versym || dso->versym[i] >= 0)
171 && (!strcmp(s, strings+syms[i].st_name)))
Rich Felker51e2d832011-06-18 19:48:42 -0400172 return syms+i;
173 }
174 return 0;
175}
176
Rich Felker2bd05a42012-08-25 17:13:28 -0400177static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
178{
Rich Felker72482f92013-08-08 16:10:35 -0400179 Sym *syms = dso->syms;
180 char *strings = dso->strings;
Rich Felker2bd05a42012-08-25 17:13:28 -0400181 uint32_t *hashtab = dso->ghashtab;
182 uint32_t nbuckets = hashtab[0];
183 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
184 uint32_t h2;
185 uint32_t *hashval;
Rich Felker72482f92013-08-08 16:10:35 -0400186 uint32_t i = buckets[h1 % nbuckets];
Rich Felker2bd05a42012-08-25 17:13:28 -0400187
Rich Felker72482f92013-08-08 16:10:35 -0400188 if (!i) return 0;
Rich Felker2bd05a42012-08-25 17:13:28 -0400189
Rich Felker72482f92013-08-08 16:10:35 -0400190 hashval = buckets + nbuckets + (i - hashtab[1]);
Rich Felker2bd05a42012-08-25 17:13:28 -0400191
Rich Felker72482f92013-08-08 16:10:35 -0400192 for (h1 |= 1; ; i++) {
Rich Felker2bd05a42012-08-25 17:13:28 -0400193 h2 = *hashval++;
Rich Felker72482f92013-08-08 16:10:35 -0400194 if ((!dso->versym || dso->versym[i] >= 0)
195 && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
196 return syms+i;
Rich Felker2bd05a42012-08-25 17:13:28 -0400197 if (h2 & 1) break;
198 }
199
200 return 0;
201}
202
Rich Felker9c748562012-10-04 22:48:33 -0400203#define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
Rich Felkere152ee92013-07-24 11:53:23 -0400204#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
Rich Felker51e2d832011-06-18 19:48:42 -0400205
Rich Felker2d8cc922014-06-30 01:18:14 -0400206#ifndef ARCH_SYM_REJECT_UND
207#define ARCH_SYM_REJECT_UND(s) 0
208#endif
209
Rich Felker9c748562012-10-04 22:48:33 -0400210static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
Rich Felker51e2d832011-06-18 19:48:42 -0400211{
Rich Felker2bd05a42012-08-25 17:13:28 -0400212 uint32_t h = 0, gh = 0;
Rich Felker9c748562012-10-04 22:48:33 -0400213 struct symdef def = {0};
Rich Felker51e2d832011-06-18 19:48:42 -0400214 for (; dso; dso=dso->next) {
Rich Felker59ab43f2011-06-26 19:23:28 -0400215 Sym *sym;
216 if (!dso->global) continue;
Rich Felker2bd05a42012-08-25 17:13:28 -0400217 if (dso->ghashtab) {
218 if (!gh) gh = gnu_hash(s);
219 sym = gnu_lookup(s, gh, dso);
220 } else {
221 if (!h) h = sysv_hash(s);
222 sym = sysv_lookup(s, h, dso);
223 }
Rich Felkerbd174312012-10-06 01:36:11 -0400224 if (!sym) continue;
225 if (!sym->st_shndx)
Rich Felker2d8cc922014-06-30 01:18:14 -0400226 if (need_def || (sym->st_info&0xf) == STT_TLS
227 || ARCH_SYM_REJECT_UND(sym))
Rich Felkerbd174312012-10-06 01:36:11 -0400228 continue;
229 if (!sym->st_value)
230 if ((sym->st_info&0xf) != STT_TLS)
231 continue;
232 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
233 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
234
235 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
236 def.sym = sym;
237 def.dso = dso;
238 if (sym->st_info>>4 == STB_GLOBAL) break;
Rich Felker51e2d832011-06-18 19:48:42 -0400239 }
Rich Felker427173b2011-07-24 02:19:47 -0400240 return def;
Rich Felker51e2d832011-06-18 19:48:42 -0400241}
242
Rich Felker1b1cafa2015-04-17 23:29:45 -0400243__attribute__((__visibility__("hidden")))
Rich Felker9d15d5e2014-06-19 02:01:06 -0400244ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
245
Rich Felker87d13a42012-08-05 02:49:02 -0400246static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
Rich Felker51e2d832011-06-18 19:48:42 -0400247{
Rich Felker87d13a42012-08-05 02:49:02 -0400248 unsigned char *base = dso->base;
249 Sym *syms = dso->syms;
250 char *strings = dso->strings;
Rich Felker51e2d832011-06-18 19:48:42 -0400251 Sym *sym;
252 const char *name;
Rich Felker51e2d832011-06-18 19:48:42 -0400253 void *ctx;
Rich Felkerf3ddd172015-04-13 02:56:26 -0400254 int type;
Rich Felker51e2d832011-06-18 19:48:42 -0400255 int sym_index;
Rich Felker9c748562012-10-04 22:48:33 -0400256 struct symdef def;
Rich Felkeradf94c12014-06-18 02:44:02 -0400257 size_t *reloc_addr;
258 size_t sym_val;
259 size_t tls_val;
260 size_t addend;
Rich Felker9bbddf72015-05-25 23:33:59 -0400261 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
262
263 if (dso == &ldso) {
264 /* Only ldso's REL table needs addend saving/reuse. */
265 if (rel == apply_addends_to)
266 reuse_addends = 1;
267 skip_relative = 1;
268 }
Rich Felker51e2d832011-06-18 19:48:42 -0400269
270 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
Rich Felker9bbddf72015-05-25 23:33:59 -0400271 if (skip_relative && IS_RELATIVE(rel[1])) continue;
Rich Felkerf3ddd172015-04-13 02:56:26 -0400272 type = R_TYPE(rel[1]);
Rich Felkerb6a6cd72015-06-04 11:45:17 -0400273 if (type == REL_NONE) continue;
Rich Felker51e2d832011-06-18 19:48:42 -0400274 sym_index = R_SYM(rel[1]);
Rich Felkeradf94c12014-06-18 02:44:02 -0400275 reloc_addr = (void *)(base + rel[0]);
Rich Felker51e2d832011-06-18 19:48:42 -0400276 if (sym_index) {
277 sym = syms + sym_index;
278 name = strings + sym->st_name;
Rich Felkeradf94c12014-06-18 02:44:02 -0400279 ctx = type==REL_COPY ? head->next : head;
280 def = find_sym(ctx, name, type==REL_PLT);
Rich Felker69003e02014-01-21 00:36:35 -0500281 if (!def.sym && (sym->st_shndx != SHN_UNDEF
282 || sym->st_info>>4 != STB_WEAK)) {
Rich Felker9a4ad022014-06-29 21:52:54 -0400283 error("Error relocating %s: %s: symbol not found",
Rich Felker87d13a42012-08-05 02:49:02 -0400284 dso->name, name);
Rich Felker01d42742015-04-18 18:00:22 -0400285 if (runtime) longjmp(*rtld_fail, 1);
Rich Felker04109502012-08-18 16:00:23 -0400286 continue;
Rich Felker6b3d5e52011-06-26 17:39:17 -0400287 }
Rich Felker7d9a5c62012-08-05 14:03:17 -0400288 } else {
Rich Felker9c748562012-10-04 22:48:33 -0400289 sym = 0;
290 def.sym = 0;
Rich Felkeradf94c12014-06-18 02:44:02 -0400291 def.dso = dso;
Rich Felker51e2d832011-06-18 19:48:42 -0400292 }
Rich Felkeradf94c12014-06-18 02:44:02 -0400293
Rich Felker9bbddf72015-05-25 23:33:59 -0400294 if (stride > 2) {
295 addend = rel[2];
296 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
297 addend = 0;
298 } else if (reuse_addends) {
299 /* Save original addend in stage 2 where the dso
300 * chain consists of just ldso; otherwise read back
301 * saved addend since the inline one was clobbered. */
302 if (head==&ldso)
303 saved_addends[save_slot] = *reloc_addr;
304 addend = saved_addends[save_slot++];
305 } else {
306 addend = *reloc_addr;
307 }
Rich Felkeradf94c12014-06-18 02:44:02 -0400308
309 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
310 tls_val = def.sym ? def.sym->st_value : 0;
311
312 switch(type) {
Rich Felkerf3ddd172015-04-13 02:56:26 -0400313 case REL_NONE:
314 break;
Rich Felkeradf94c12014-06-18 02:44:02 -0400315 case REL_OFFSET:
316 addend -= (size_t)reloc_addr;
317 case REL_SYMBOLIC:
318 case REL_GOT:
319 case REL_PLT:
320 *reloc_addr = sym_val + addend;
321 break;
322 case REL_RELATIVE:
323 *reloc_addr = (size_t)base + addend;
324 break;
325 case REL_SYM_OR_REL:
326 if (sym) *reloc_addr = sym_val + addend;
327 else *reloc_addr = (size_t)base + addend;
328 break;
329 case REL_COPY:
330 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
331 break;
332 case REL_OFFSET32:
333 *(uint32_t *)reloc_addr = sym_val + addend
334 - (size_t)reloc_addr;
335 break;
336 case REL_DTPMOD:
337 *reloc_addr = def.dso->tls_id;
338 break;
339 case REL_DTPOFF:
340 *reloc_addr = tls_val + addend;
341 break;
342#ifdef TLS_ABOVE_TP
343 case REL_TPOFF:
344 *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
345 break;
346#else
347 case REL_TPOFF:
348 *reloc_addr = tls_val - def.dso->tls_offset + addend;
349 break;
350 case REL_TPOFF_NEG:
351 *reloc_addr = def.dso->tls_offset - tls_val + addend;
352 break;
353#endif
Rich Felker9d15d5e2014-06-19 02:01:06 -0400354 case REL_TLSDESC:
355 if (stride<3) addend = reloc_addr[1];
356 if (runtime && def.dso->tls_id >= static_tls_cnt) {
357 struct td_index *new = malloc(sizeof *new);
Rich Felker01d42742015-04-18 18:00:22 -0400358 if (!new) {
359 error(
Rich Felker9d15d5e2014-06-19 02:01:06 -0400360 "Error relocating %s: cannot allocate TLSDESC for %s",
361 dso->name, sym ? name : "(local)" );
Rich Felkerc5ab5bd2015-04-21 13:22:48 -0400362 longjmp(*rtld_fail, 1);
Rich Felker01d42742015-04-18 18:00:22 -0400363 }
Rich Felker9d15d5e2014-06-19 02:01:06 -0400364 new->next = dso->td_index;
365 dso->td_index = new;
366 new->args[0] = def.dso->tls_id;
367 new->args[1] = tls_val + addend;
368 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
369 reloc_addr[1] = (size_t)new;
370 } else {
371 reloc_addr[0] = (size_t)__tlsdesc_static;
372#ifdef TLS_ABOVE_TP
373 reloc_addr[1] = tls_val + def.dso->tls_offset
374 + TPOFF_K + addend;
375#else
376 reloc_addr[1] = tls_val - def.dso->tls_offset
377 + addend;
378#endif
379 }
380 break;
Rich Felkerf3ddd172015-04-13 02:56:26 -0400381 default:
382 error("Error relocating %s: unsupported relocation type %d",
383 dso->name, type);
Rich Felker01d42742015-04-18 18:00:22 -0400384 if (runtime) longjmp(*rtld_fail, 1);
Rich Felkerf3ddd172015-04-13 02:56:26 -0400385 continue;
Rich Felkeradf94c12014-06-18 02:44:02 -0400386 }
Rich Felker51e2d832011-06-18 19:48:42 -0400387 }
388}
389
Rich Felker6717e622011-06-28 19:40:14 -0400390/* A huge hack: to make up for the wastefulness of shared libraries
391 * needing at least a page of dirty memory even if they have no global
392 * data, we reclaim the gaps at the beginning and end of writable maps
393 * and "donate" them to the heap by setting up minimal malloc
394 * structures and then freeing them. */
395
Timo Teräse13a2b82014-03-25 14:13:27 +0200396static void reclaim(struct dso *dso, size_t start, size_t end)
Rich Felker6717e622011-06-28 19:40:14 -0400397{
398 size_t *a, *z;
Timo Teräse13a2b82014-03-25 14:13:27 +0200399 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
400 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
Rich Felker6717e622011-06-28 19:40:14 -0400401 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
402 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
403 if (start>end || end-start < 4*sizeof(size_t)) return;
Timo Teräse13a2b82014-03-25 14:13:27 +0200404 a = (size_t *)(dso->base + start);
405 z = (size_t *)(dso->base + end);
Rich Felker6717e622011-06-28 19:40:14 -0400406 a[-2] = 1;
407 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
408 z[1] = 1;
409 free(a);
410}
411
Timo Teräs87691962014-03-25 20:59:50 +0200412static void reclaim_gaps(struct dso *dso)
Rich Felker6717e622011-06-28 19:40:14 -0400413{
Rich Felkerfa7248c2014-03-25 16:21:50 -0400414 Phdr *ph = dso->phdr;
415 size_t phcnt = dso->phnum;
Timo Teräs87691962014-03-25 20:59:50 +0200416
Rich Felkerfa7248c2014-03-25 16:21:50 -0400417 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
Rich Felker6717e622011-06-28 19:40:14 -0400418 if (ph->p_type!=PT_LOAD) continue;
419 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
Timo Teräse13a2b82014-03-25 14:13:27 +0200420 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
421 reclaim(dso, ph->p_vaddr+ph->p_memsz,
Rich Felker6717e622011-06-28 19:40:14 -0400422 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
423 }
424}
425
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400426static void *map_library(int fd, struct dso *dso)
Rich Felker51e2d832011-06-18 19:48:42 -0400427{
Rich Felker59633c72011-06-25 12:26:08 -0400428 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
Rich Felkerd5884a52013-08-02 09:56:49 -0400429 void *allocated_buf=0;
Rich Felker51e2d832011-06-18 19:48:42 -0400430 size_t phsize;
431 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
432 size_t this_min, this_max;
433 off_t off_start;
434 Ehdr *eh;
Rich Felker30763fd2013-07-10 14:38:20 -0400435 Phdr *ph, *ph0;
Rich Felker51e2d832011-06-18 19:48:42 -0400436 unsigned prot;
Rich Felkerd5884a52013-08-02 09:56:49 -0400437 unsigned char *map=MAP_FAILED, *base;
Rich Felker7443dd22013-08-02 09:25:12 -0400438 size_t dyn=0;
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400439 size_t tls_image=0;
Rich Felker51e2d832011-06-18 19:48:42 -0400440 size_t i;
441
442 ssize_t l = read(fd, buf, sizeof buf);
Rich Felker59633c72011-06-25 12:26:08 -0400443 eh = buf;
Rich Felkerd5884a52013-08-02 09:56:49 -0400444 if (l<0) return 0;
445 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
446 goto noexec;
Rich Felker51e2d832011-06-18 19:48:42 -0400447 phsize = eh->e_phentsize * eh->e_phnum;
Rich Felkerd5884a52013-08-02 09:56:49 -0400448 if (phsize > sizeof buf - sizeof *eh) {
449 allocated_buf = malloc(phsize);
450 if (!allocated_buf) return 0;
451 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
452 if (l < 0) goto error;
453 if (l != phsize) goto noexec;
454 ph = ph0 = allocated_buf;
455 } else if (eh->e_phoff + phsize > l) {
Rich Felker59633c72011-06-25 12:26:08 -0400456 l = pread(fd, buf+1, phsize, eh->e_phoff);
Rich Felkerd5884a52013-08-02 09:56:49 -0400457 if (l < 0) goto error;
458 if (l != phsize) goto noexec;
Rich Felker30763fd2013-07-10 14:38:20 -0400459 ph = ph0 = (void *)(buf + 1);
460 } else {
461 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
Rich Felker51e2d832011-06-18 19:48:42 -0400462 }
Rich Felker51e2d832011-06-18 19:48:42 -0400463 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
Rich Felkerfa7248c2014-03-25 16:21:50 -0400464 if (ph->p_type == PT_DYNAMIC) {
Rich Felker51e2d832011-06-18 19:48:42 -0400465 dyn = ph->p_vaddr;
Rich Felkerfa7248c2014-03-25 16:21:50 -0400466 } else if (ph->p_type == PT_TLS) {
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400467 tls_image = ph->p_vaddr;
468 dso->tls_align = ph->p_align;
469 dso->tls_len = ph->p_filesz;
470 dso->tls_size = ph->p_memsz;
Timo Teräse13a2b82014-03-25 14:13:27 +0200471 } else if (ph->p_type == PT_GNU_RELRO) {
472 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
473 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400474 }
Rich Felker51e2d832011-06-18 19:48:42 -0400475 if (ph->p_type != PT_LOAD) continue;
476 if (ph->p_vaddr < addr_min) {
477 addr_min = ph->p_vaddr;
478 off_start = ph->p_offset;
479 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
480 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
481 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
482 }
483 if (ph->p_vaddr+ph->p_memsz > addr_max) {
484 addr_max = ph->p_vaddr+ph->p_memsz;
485 }
486 }
Rich Felkerd5884a52013-08-02 09:56:49 -0400487 if (!dyn) goto noexec;
Rich Felker51e2d832011-06-18 19:48:42 -0400488 addr_max += PAGE_SIZE-1;
489 addr_max &= -PAGE_SIZE;
490 addr_min &= -PAGE_SIZE;
491 off_start &= -PAGE_SIZE;
492 map_len = addr_max - addr_min + off_start;
493 /* The first time, we map too much, possibly even more than
494 * the length of the file. This is okay because we will not
495 * use the invalid part; we just need to reserve the right
496 * amount of virtual address space to map over later. */
Rich Felkerbf301002011-06-28 14:20:41 -0400497 map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
Rich Felkerd5884a52013-08-02 09:56:49 -0400498 if (map==MAP_FAILED) goto error;
Rich Felker339516a2013-07-31 14:42:08 -0400499 /* If the loaded file is not relocatable and the requested address is
500 * not available, then the load operation must fail. */
501 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
502 errno = EBUSY;
503 goto error;
504 }
Rich Felker51e2d832011-06-18 19:48:42 -0400505 base = map - addr_min;
Rich Felker30763fd2013-07-10 14:38:20 -0400506 dso->phdr = 0;
507 dso->phnum = 0;
508 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
Rich Felker51e2d832011-06-18 19:48:42 -0400509 if (ph->p_type != PT_LOAD) continue;
Rich Felker30763fd2013-07-10 14:38:20 -0400510 /* Check if the programs headers are in this load segment, and
511 * if so, record the address for use by dl_iterate_phdr. */
512 if (!dso->phdr && eh->e_phoff >= ph->p_offset
513 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
514 dso->phdr = (void *)(base + ph->p_vaddr
515 + (eh->e_phoff-ph->p_offset));
516 dso->phnum = eh->e_phnum;
Timo Teräs87691962014-03-25 20:59:50 +0200517 dso->phentsize = eh->e_phentsize;
Rich Felker30763fd2013-07-10 14:38:20 -0400518 }
Rich Felker51e2d832011-06-18 19:48:42 -0400519 /* Reuse the existing mapping for the lowest-address LOAD */
520 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
521 this_min = ph->p_vaddr & -PAGE_SIZE;
522 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
523 off_start = ph->p_offset & -PAGE_SIZE;
524 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
525 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
526 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
Rich Felkerf7d15dc2012-06-06 11:21:28 -0400527 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
528 goto error;
Rich Felker51e2d832011-06-18 19:48:42 -0400529 if (ph->p_memsz > ph->p_filesz) {
530 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
531 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
532 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
Rich Felkerf7d15dc2012-06-06 11:21:28 -0400533 if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
534 goto error;
Rich Felker51e2d832011-06-18 19:48:42 -0400535 }
536 }
Rich Felker9f174132011-06-29 00:29:08 -0400537 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
538 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
Rich Felkerf7d15dc2012-06-06 11:21:28 -0400539 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
540 goto error;
Rich Felker9f174132011-06-29 00:29:08 -0400541 break;
542 }
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400543 dso->map = map;
544 dso->map_len = map_len;
545 dso->base = base;
546 dso->dynv = (void *)(base+dyn);
547 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
Timo Teräs87691962014-03-25 20:59:50 +0200548 if (!runtime) reclaim_gaps(dso);
Rich Felker8d01dfc2013-08-02 09:59:02 -0400549 free(allocated_buf);
Rich Felker51e2d832011-06-18 19:48:42 -0400550 return map;
Rich Felkerd5884a52013-08-02 09:56:49 -0400551noexec:
552 errno = ENOEXEC;
Rich Felkerf7d15dc2012-06-06 11:21:28 -0400553error:
Rich Felkerd5884a52013-08-02 09:56:49 -0400554 if (map!=MAP_FAILED) munmap(map, map_len);
555 free(allocated_buf);
Rich Felkerf7d15dc2012-06-06 11:21:28 -0400556 return 0;
Rich Felker51e2d832011-06-18 19:48:42 -0400557}
558
Rich Felker8c203ea2013-04-20 11:51:58 -0400559static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
Rich Felker568b8072011-06-25 01:56:34 -0400560{
Rich Felker8c203ea2013-04-20 11:51:58 -0400561 size_t l;
562 int fd;
Rich Felker49388f32011-06-25 17:49:16 -0400563 for (;;) {
Rich Felker8c203ea2013-04-20 11:51:58 -0400564 s += strspn(s, ":\n");
565 l = strcspn(s, ":\n");
566 if (l-1 >= INT_MAX) return -1;
Rich Felker5d1c8c92015-04-01 20:27:29 -0400567 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
568 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
569 switch (errno) {
570 case ENOENT:
571 case ENOTDIR:
572 case EACCES:
573 case ENAMETOOLONG:
574 break;
575 default:
576 /* Any negative value but -1 will inhibit
577 * futher path search. */
578 return -2;
579 }
580 }
Rich Felker49388f32011-06-25 17:49:16 -0400581 s += l;
Rich Felker568b8072011-06-25 01:56:34 -0400582 }
Rich Felker568b8072011-06-25 01:56:34 -0400583}
584
Rich Felkera897a202013-08-23 13:56:30 -0400585static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
586{
587 size_t n, l;
588 const char *s, *t, *origin;
589 char *d;
Rich Felker2963a9f2015-04-03 16:35:43 -0400590 if (p->rpath || !p->rpath_orig) return 0;
Rich Felkera897a202013-08-23 13:56:30 -0400591 if (!strchr(p->rpath_orig, '$')) {
592 p->rpath = p->rpath_orig;
593 return 0;
594 }
595 n = 0;
596 s = p->rpath_orig;
Rich Felkerd2c42ed2013-08-23 15:51:59 -0400597 while ((t=strchr(s, '$'))) {
598 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
Rich Felker2963a9f2015-04-03 16:35:43 -0400599 return 0;
Rich Felkera897a202013-08-23 13:56:30 -0400600 s = t+1;
601 n++;
602 }
Rich Felker2963a9f2015-04-03 16:35:43 -0400603 if (n > SSIZE_MAX/PATH_MAX) return 0;
Rich Felkera897a202013-08-23 13:56:30 -0400604
605 if (p->kernel_mapped) {
606 /* $ORIGIN searches cannot be performed for the main program
607 * when it is suid/sgid/AT_SECURE. This is because the
608 * pathname is under the control of the caller of execve.
609 * For libraries, however, $ORIGIN can be processed safely
610 * since the library's pathname came from a trusted source
611 * (either system paths or a call to dlopen). */
612 if (libc.secure)
Rich Felker2963a9f2015-04-03 16:35:43 -0400613 return 0;
Rich Felkerd2c42ed2013-08-23 15:51:59 -0400614 l = readlink("/proc/self/exe", buf, buf_size);
Rich Felker2963a9f2015-04-03 16:35:43 -0400615 if (l == -1) switch (errno) {
616 case ENOENT:
617 case ENOTDIR:
618 case EACCES:
619 break;
620 default:
Rich Felkera897a202013-08-23 13:56:30 -0400621 return -1;
Rich Felker2963a9f2015-04-03 16:35:43 -0400622 }
623 if (l >= buf_size)
624 return 0;
Rich Felkerd2c42ed2013-08-23 15:51:59 -0400625 buf[l] = 0;
Rich Felkera897a202013-08-23 13:56:30 -0400626 origin = buf;
627 } else {
628 origin = p->name;
629 }
630 t = strrchr(origin, '/');
631 l = t ? t-origin : 0;
632 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
633 if (!p->rpath) return -1;
634
635 d = p->rpath;
636 s = p->rpath_orig;
Rich Felkerd2c42ed2013-08-23 15:51:59 -0400637 while ((t=strchr(s, '$'))) {
Rich Felkera897a202013-08-23 13:56:30 -0400638 memcpy(d, s, t-s);
639 d += t-s;
640 memcpy(d, origin, l);
641 d += l;
Rich Felkerd2c42ed2013-08-23 15:51:59 -0400642 /* It was determined previously that the '$' is followed
643 * either by "ORIGIN" or "{ORIGIN}". */
Rich Felkera897a202013-08-23 13:56:30 -0400644 s = t + 7 + 2*(t[1]=='{');
645 }
646 strcpy(d, s);
647 return 0;
648}
649
Rich Felkerc82f4a32012-01-23 00:57:38 -0500650static void decode_dyn(struct dso *p)
651{
Rich Felkerf4f95622015-04-13 22:38:18 -0400652 size_t dyn[DYN_CNT];
Rich Felkerc82f4a32012-01-23 00:57:38 -0500653 decode_vec(p->dynv, dyn, DYN_CNT);
654 p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
Rich Felkerc82f4a32012-01-23 00:57:38 -0500655 p->strings = (void *)(p->base + dyn[DT_STRTAB]);
Rich Felker2bd05a42012-08-25 17:13:28 -0400656 if (dyn[0]&(1<<DT_HASH))
657 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
Rich Felker709355e2013-08-23 11:15:40 -0400658 if (dyn[0]&(1<<DT_RPATH))
Rich Felkera897a202013-08-23 13:56:30 -0400659 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
Rich Felkerd8dc2b72014-11-23 16:17:57 -0500660 if (dyn[0]&(1<<DT_RUNPATH))
661 p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
Rich Felker2bd05a42012-08-25 17:13:28 -0400662 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
663 p->ghashtab = (void *)(p->base + *dyn);
Rich Felker72482f92013-08-08 16:10:35 -0400664 if (search_vec(p->dynv, dyn, DT_VERSYM))
665 p->versym = (void *)(p->base + *dyn);
Rich Felkerc82f4a32012-01-23 00:57:38 -0500666}
667
Rich Felker709355e2013-08-23 11:15:40 -0400668static struct dso *load_library(const char *name, struct dso *needed_by)
Rich Felker51e2d832011-06-18 19:48:42 -0400669{
Rich Felker5c1909a2012-05-27 16:01:44 -0400670 char buf[2*NAME_MAX+2];
Rich Felker0420b872012-07-11 01:41:20 -0400671 const char *pathname;
Rich Felker1d7c4f82012-12-15 23:34:08 -0500672 unsigned char *map;
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400673 struct dso *p, temp_dso = {0};
Rich Felker51e2d832011-06-18 19:48:42 -0400674 int fd;
675 struct stat st;
Rich Felkerdcd60372012-10-05 11:51:50 -0400676 size_t alloc_size;
677 int n_th = 0;
Rich Felkerf8c376d2013-07-31 14:59:36 -0400678 int is_self = 0;
Rich Felker51e2d832011-06-18 19:48:42 -0400679
Rich Felker59549312014-07-11 00:29:44 -0400680 if (!*name) {
681 errno = EINVAL;
682 return 0;
683 }
684
Rich Felker51e2d832011-06-18 19:48:42 -0400685 /* Catch and block attempts to reload the implementation itself */
686 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
687 static const char *rp, reserved[] =
688 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
689 char *z = strchr(name, '.');
690 if (z) {
691 size_t l = z-name;
Rich Felker27593d32013-07-31 15:14:06 -0400692 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
Rich Felker51e2d832011-06-18 19:48:42 -0400693 if (*rp) {
Rich Felkera97a0502013-07-26 14:41:12 -0400694 if (ldd_mode) {
695 /* Track which names have been resolved
696 * and only report each one once. */
697 static unsigned reported;
698 unsigned mask = 1U<<(rp-reserved);
699 if (!(reported & mask)) {
700 reported |= mask;
701 dprintf(1, "\t%s => %s (%p)\n",
Rich Felkerf3ddd172015-04-13 02:56:26 -0400702 name, ldso.name,
703 ldso.base);
Rich Felkera97a0502013-07-26 14:41:12 -0400704 }
705 }
Rich Felkerf8c376d2013-07-31 14:59:36 -0400706 is_self = 1;
Rich Felker51e2d832011-06-18 19:48:42 -0400707 }
708 }
709 }
Rich Felkerf3ddd172015-04-13 02:56:26 -0400710 if (!strcmp(name, ldso.name)) is_self = 1;
Rich Felkerf8c376d2013-07-31 14:59:36 -0400711 if (is_self) {
Rich Felkerf3ddd172015-04-13 02:56:26 -0400712 if (!ldso.prev) {
713 tail->next = &ldso;
714 ldso.prev = tail;
715 tail = ldso.next ? ldso.next : &ldso;
Rich Felkerf8c376d2013-07-31 14:59:36 -0400716 }
Rich Felkerf3ddd172015-04-13 02:56:26 -0400717 return &ldso;
Rich Felkerf8c376d2013-07-31 14:59:36 -0400718 }
Rich Felker59ab43f2011-06-26 19:23:28 -0400719 if (strchr(name, '/')) {
Rich Felker0420b872012-07-11 01:41:20 -0400720 pathname = name;
Rich Felkerf2d08cf2012-09-29 17:59:50 -0400721 fd = open(name, O_RDONLY|O_CLOEXEC);
Rich Felker51e2d832011-06-18 19:48:42 -0400722 } else {
Rich Felker0420b872012-07-11 01:41:20 -0400723 /* Search for the name to see if it's already loaded */
724 for (p=head->next; p; p=p->next) {
725 if (p->shortname && !strcmp(p->shortname, name)) {
726 p->refcnt++;
727 return p;
728 }
729 }
Rich Felker59ab43f2011-06-26 19:23:28 -0400730 if (strlen(name) > NAME_MAX) return 0;
Rich Felker568b8072011-06-25 01:56:34 -0400731 fd = -1;
Rich Felker3e3753c2013-08-02 10:02:29 -0400732 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
Rich Felker2963a9f2015-04-03 16:35:43 -0400733 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
734 if (fixup_rpath(p, buf, sizeof buf) < 0)
735 fd = -2; /* Inhibit further search. */
736 if (p->rpath)
Rich Felker709355e2013-08-23 11:15:40 -0400737 fd = path_open(name, p->rpath, buf, sizeof buf);
Rich Felker2963a9f2015-04-03 16:35:43 -0400738 }
Rich Felker5d1c8c92015-04-01 20:27:29 -0400739 if (fd == -1) {
Rich Felker568b8072011-06-25 01:56:34 -0400740 if (!sys_path) {
Rich Felkerf389c492013-07-18 19:29:44 -0400741 char *prefix = 0;
742 size_t prefix_len;
Rich Felkerf3ddd172015-04-13 02:56:26 -0400743 if (ldso.name[0]=='/') {
Rich Felkerf389c492013-07-18 19:29:44 -0400744 char *s, *t, *z;
Rich Felkerf3ddd172015-04-13 02:56:26 -0400745 for (s=t=z=ldso.name; *s; s++)
Rich Felkerf389c492013-07-18 19:29:44 -0400746 if (*s=='/') z=t, t=s;
Rich Felkerf3ddd172015-04-13 02:56:26 -0400747 prefix_len = z-ldso.name;
Rich Felkerf389c492013-07-18 19:29:44 -0400748 if (prefix_len < PATH_MAX)
Rich Felkerf3ddd172015-04-13 02:56:26 -0400749 prefix = ldso.name;
Rich Felkerf389c492013-07-18 19:29:44 -0400750 }
751 if (!prefix) {
752 prefix = "";
753 prefix_len = 0;
754 }
755 char etc_ldso_path[prefix_len + 1
756 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
757 snprintf(etc_ldso_path, sizeof etc_ldso_path,
758 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
759 (int)prefix_len, prefix);
760 FILE *f = fopen(etc_ldso_path, "rbe");
Rich Felker568b8072011-06-25 01:56:34 -0400761 if (f) {
Rich Felker11bc1732013-06-26 10:17:29 -0400762 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
Rich Felker59b481d2013-06-26 10:51:36 -0400763 free(sys_path);
Rich Felker11bc1732013-06-26 10:17:29 -0400764 sys_path = "";
Rich Felker65465102012-11-09 13:49:40 -0500765 }
Rich Felker568b8072011-06-25 01:56:34 -0400766 fclose(f);
Rich Felkerff4be702013-09-09 13:39:08 -0400767 } else if (errno != ENOENT) {
768 sys_path = "";
Rich Felker568b8072011-06-25 01:56:34 -0400769 }
770 }
Rich Felker40d5f7e2012-11-08 22:41:16 -0500771 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
772 fd = path_open(name, sys_path, buf, sizeof buf);
Rich Felker51e2d832011-06-18 19:48:42 -0400773 }
Rich Felker0420b872012-07-11 01:41:20 -0400774 pathname = buf;
Rich Felker51e2d832011-06-18 19:48:42 -0400775 }
776 if (fd < 0) return 0;
777 if (fstat(fd, &st) < 0) {
778 close(fd);
779 return 0;
780 }
781 for (p=head->next; p; p=p->next) {
782 if (p->dev == st.st_dev && p->ino == st.st_ino) {
Rich Felker0420b872012-07-11 01:41:20 -0400783 /* If this library was previously loaded with a
784 * pathname but a search found the same inode,
785 * setup its shortname so it can be found by name. */
Rich Felker5f88c0e2012-10-05 12:09:54 -0400786 if (!p->shortname && pathname != name)
787 p->shortname = strrchr(p->name, '/')+1;
Rich Felker51e2d832011-06-18 19:48:42 -0400788 close(fd);
789 p->refcnt++;
790 return p;
791 }
792 }
Rich Felker4d07e552013-01-23 22:07:45 -0500793 map = noload ? 0 : map_library(fd, &temp_dso);
Rich Felker51e2d832011-06-18 19:48:42 -0400794 close(fd);
795 if (!map) return 0;
Rich Felkerdcd60372012-10-05 11:51:50 -0400796
797 /* Allocate storage for the new DSO. When there is TLS, this
798 * storage must include a reservation for all pre-existing
799 * threads to obtain copies of both the new TLS, and an
800 * extended DTV capable of storing an additional slot for
801 * the newly-loaded DSO. */
802 alloc_size = sizeof *p + strlen(pathname) + 1;
803 if (runtime && temp_dso.tls_image) {
804 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
805 + sizeof(void *) * (tls_cnt+3);
Rich Felkere23d3582012-10-13 23:25:20 -0400806 n_th = libc.threads_minus_1 + 1;
Rich Felkerdcd60372012-10-05 11:51:50 -0400807 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
808 else alloc_size += n_th * per_th;
809 }
810 p = calloc(1, alloc_size);
Rich Felker51e2d832011-06-18 19:48:42 -0400811 if (!p) {
Rich Felker74025c82013-02-02 00:59:25 -0500812 munmap(map, temp_dso.map_len);
Rich Felker51e2d832011-06-18 19:48:42 -0400813 return 0;
814 }
Rich Felkerbc6a35f2012-10-04 20:04:13 -0400815 memcpy(p, &temp_dso, sizeof temp_dso);
Rich Felkerc82f4a32012-01-23 00:57:38 -0500816 decode_dyn(p);
Rich Felker51e2d832011-06-18 19:48:42 -0400817 p->dev = st.st_dev;
818 p->ino = st.st_ino;
Rich Felker51e2d832011-06-18 19:48:42 -0400819 p->refcnt = 1;
Rich Felker709355e2013-08-23 11:15:40 -0400820 p->needed_by = needed_by;
Rich Felker6b3d5e52011-06-26 17:39:17 -0400821 p->name = p->buf;
Rich Felker0420b872012-07-11 01:41:20 -0400822 strcpy(p->name, pathname);
823 /* Add a shortname only if name arg was not an explicit pathname. */
824 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
Rich Felkerdcd60372012-10-05 11:51:50 -0400825 if (p->tls_image) {
826 p->tls_id = ++tls_cnt;
Rich Felkercf3fd3d2012-10-06 01:22:51 -0400827 tls_align = MAXP2(tls_align, p->tls_align);
Rich Felker9ec42832012-10-15 18:51:53 -0400828#ifdef TLS_ABOVE_TP
829 p->tls_offset = tls_offset + ( (tls_align-1) &
830 -(tls_offset + (uintptr_t)p->tls_image) );
831 tls_offset += p->tls_size;
832#else
Rich Felkercf3fd3d2012-10-06 01:22:51 -0400833 tls_offset += p->tls_size + p->tls_align - 1;
834 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
835 & (p->tls_align-1);
836 p->tls_offset = tls_offset;
Rich Felker9ec42832012-10-15 18:51:53 -0400837#endif
Rich Felkerdcd60372012-10-05 11:51:50 -0400838 p->new_dtv = (void *)(-sizeof(size_t) &
839 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
840 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
841 }
Rich Felker51e2d832011-06-18 19:48:42 -0400842
843 tail->next = p;
844 p->prev = tail;
845 tail = p;
846
Rich Felker1d7c4f82012-12-15 23:34:08 -0500847 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
Rich Felker5c1909a2012-05-27 16:01:44 -0400848
Rich Felker51e2d832011-06-18 19:48:42 -0400849 return p;
850}
851
852static void load_deps(struct dso *p)
853{
Rich Felker59ab43f2011-06-26 19:23:28 -0400854 size_t i, ndeps=0;
855 struct dso ***deps = &p->deps, **tmp, *dep;
Rich Felker51e2d832011-06-18 19:48:42 -0400856 for (; p; p=p->next) {
857 for (i=0; p->dynv[i]; i+=2) {
858 if (p->dynv[i] != DT_NEEDED) continue;
Rich Felker709355e2013-08-23 11:15:40 -0400859 dep = load_library(p->strings + p->dynv[i+1], p);
Rich Felker59ab43f2011-06-26 19:23:28 -0400860 if (!dep) {
Rich Felker9a4ad022014-06-29 21:52:54 -0400861 error("Error loading shared library %s: %m (needed by %s)",
Rich Felker6b3d5e52011-06-26 17:39:17 -0400862 p->strings + p->dynv[i+1], p->name);
Rich Felker01d42742015-04-18 18:00:22 -0400863 if (runtime) longjmp(*rtld_fail, 1);
Rich Felker04109502012-08-18 16:00:23 -0400864 continue;
Rich Felker6b3d5e52011-06-26 17:39:17 -0400865 }
Rich Felker59ab43f2011-06-26 19:23:28 -0400866 if (runtime) {
867 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
Rich Felker17276be2013-07-24 02:38:05 -0400868 if (!tmp) longjmp(*rtld_fail, 1);
Rich Felker59ab43f2011-06-26 19:23:28 -0400869 tmp[ndeps++] = dep;
870 tmp[ndeps] = 0;
871 *deps = tmp;
872 }
Rich Felker51e2d832011-06-18 19:48:42 -0400873 }
874 }
875}
876
Rich Felker2719cc82011-08-16 00:24:36 -0400877static void load_preload(char *s)
878{
879 int tmp;
880 char *z;
881 for (z=s; *z; s=z) {
Rich Felker349381a2014-07-11 00:26:12 -0400882 for ( ; *s && (isspace(*s) || *s==':'); s++);
883 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
Rich Felker2719cc82011-08-16 00:24:36 -0400884 tmp = *z;
885 *z = 0;
Rich Felker709355e2013-08-23 11:15:40 -0400886 load_library(s, 0);
Rich Felker2719cc82011-08-16 00:24:36 -0400887 *z = tmp;
888 }
889}
890
Rich Felker59ab43f2011-06-26 19:23:28 -0400891static void make_global(struct dso *p)
892{
893 for (; p; p=p->next) p->global = 1;
894}
895
Rich Felkerf3ddd172015-04-13 02:56:26 -0400896static void do_mips_relocs(struct dso *p, size_t *got)
897{
898 size_t i, j, rel[2];
899 unsigned char *base = p->base;
900 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
Rich Felker9bbddf72015-05-25 23:33:59 -0400901 if (p==&ldso) {
Rich Felkerf3ddd172015-04-13 02:56:26 -0400902 got += i;
903 } else {
904 while (i--) *got++ += (size_t)base;
905 }
906 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
907 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
908 Sym *sym = p->syms + j;
909 rel[0] = (unsigned char *)got - base;
910 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
911 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
912 do_relocs(p, rel, sizeof rel, 2);
913 }
914}
915
Rich Felker51e2d832011-06-18 19:48:42 -0400916static void reloc_all(struct dso *p)
917{
Rich Felkerf4f95622015-04-13 22:38:18 -0400918 size_t dyn[DYN_CNT];
Rich Felker51e2d832011-06-18 19:48:42 -0400919 for (; p; p=p->next) {
920 if (p->relocated) continue;
921 decode_vec(p->dynv, dyn, DYN_CNT);
Rich Felkerf3ddd172015-04-13 02:56:26 -0400922 if (NEED_MIPS_GOT_RELOCS)
923 do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
Rich Felker87d13a42012-08-05 02:49:02 -0400924 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
925 2+(dyn[DT_PLTREL]==DT_RELA));
926 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
927 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
Timo Teräse13a2b82014-03-25 14:13:27 +0200928
Rich Felkerf3ddd172015-04-13 02:56:26 -0400929 if (head != &ldso && p->relro_start != p->relro_end &&
Timo Teräse13a2b82014-03-25 14:13:27 +0200930 mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
Rich Felker9a4ad022014-06-29 21:52:54 -0400931 error("Error relocating %s: RELRO protection failed: %m",
Timo Teräse13a2b82014-03-25 14:13:27 +0200932 p->name);
Rich Felker01d42742015-04-18 18:00:22 -0400933 if (runtime) longjmp(*rtld_fail, 1);
Timo Teräse13a2b82014-03-25 14:13:27 +0200934 }
935
Rich Felker368ba4a2011-06-25 00:18:19 -0400936 p->relocated = 1;
Rich Felker51e2d832011-06-18 19:48:42 -0400937 }
938}
939
Timo Teräs87691962014-03-25 20:59:50 +0200940static void kernel_mapped_dso(struct dso *p)
Rich Felkerc82f4a32012-01-23 00:57:38 -0500941{
Timo Teräs87691962014-03-25 20:59:50 +0200942 size_t min_addr = -1, max_addr = 0, cnt;
943 Phdr *ph = p->phdr;
944 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
945 if (ph->p_type == PT_DYNAMIC) {
946 p->dynv = (void *)(p->base + ph->p_vaddr);
947 } else if (ph->p_type == PT_GNU_RELRO) {
Timo Teräse13a2b82014-03-25 14:13:27 +0200948 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
949 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
950 }
Rich Felkerf419bcb2012-08-26 21:09:26 -0400951 if (ph->p_type != PT_LOAD) continue;
952 if (ph->p_vaddr < min_addr)
953 min_addr = ph->p_vaddr;
954 if (ph->p_vaddr+ph->p_memsz > max_addr)
955 max_addr = ph->p_vaddr+ph->p_memsz;
956 }
957 min_addr &= -PAGE_SIZE;
958 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
959 p->map = p->base + min_addr;
960 p->map_len = max_addr - min_addr;
Timo Teräs87691962014-03-25 20:59:50 +0200961 p->kernel_mapped = 1;
Rich Felkerf419bcb2012-08-26 21:09:26 -0400962}
963
Rich Felkerf4f77c02012-10-05 13:09:09 -0400964static void do_fini()
965{
966 struct dso *p;
Rich Felkerf4f95622015-04-13 22:38:18 -0400967 size_t dyn[DYN_CNT];
Rich Felkerf4f77c02012-10-05 13:09:09 -0400968 for (p=fini_head; p; p=p->fini_next) {
969 if (!p->constructed) continue;
970 decode_vec(p->dynv, dyn, DYN_CNT);
Rich Felkere69ae842013-07-20 18:26:17 -0400971 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
972 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
Rich Felker1b413572013-07-21 02:35:46 -0400973 size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
974 while (n--) ((void (*)(void))*--fn)();
Rich Felkere69ae842013-07-20 18:26:17 -0400975 }
Rich Felker1da53da2013-07-22 14:08:33 -0400976#ifndef NO_LEGACY_INITFINI
Rich Felkerd0c6cb02013-07-31 00:04:10 -0400977 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
Rich Felkere69ae842013-07-20 18:26:17 -0400978 ((void (*)(void))(p->base + dyn[DT_FINI]))();
Rich Felker1da53da2013-07-22 14:08:33 -0400979#endif
Rich Felkerf4f77c02012-10-05 13:09:09 -0400980 }
981}
982
Rich Felker4ce3cb52012-02-06 14:39:09 -0500983static void do_init_fini(struct dso *p)
984{
Rich Felkerf4f95622015-04-13 22:38:18 -0400985 size_t dyn[DYN_CNT];
Rich Felkere23d3582012-10-13 23:25:20 -0400986 int need_locking = libc.threads_minus_1;
Rich Felkerf4f77c02012-10-05 13:09:09 -0400987 /* Allow recursive calls that arise when a library calls
988 * dlopen from one of its constructors, but block any
989 * other threads until all ctors have finished. */
990 if (need_locking) pthread_mutex_lock(&init_fini_lock);
Rich Felker4ce3cb52012-02-06 14:39:09 -0500991 for (; p; p=p->prev) {
Rich Felkerf4f77c02012-10-05 13:09:09 -0400992 if (p->constructed) continue;
993 p->constructed = 1;
Rich Felker4ce3cb52012-02-06 14:39:09 -0500994 decode_vec(p->dynv, dyn, DYN_CNT);
Rich Felkere69ae842013-07-20 18:26:17 -0400995 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
Rich Felkerf4f77c02012-10-05 13:09:09 -0400996 p->fini_next = fini_head;
997 fini_head = p;
998 }
Rich Felker1da53da2013-07-22 14:08:33 -0400999#ifndef NO_LEGACY_INITFINI
Rich Felkerd0c6cb02013-07-31 00:04:10 -04001000 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
Rich Felker4ce3cb52012-02-06 14:39:09 -05001001 ((void (*)(void))(p->base + dyn[DT_INIT]))();
Rich Felker1da53da2013-07-22 14:08:33 -04001002#endif
Rich Felkere69ae842013-07-20 18:26:17 -04001003 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1004 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1005 size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
1006 while (n--) ((void (*)(void))*fn++)();
1007 }
Rich Felker509b50e2013-06-29 02:24:02 -04001008 if (!need_locking && libc.threads_minus_1) {
1009 need_locking = 1;
1010 pthread_mutex_lock(&init_fini_lock);
1011 }
Rich Felker4ce3cb52012-02-06 14:39:09 -05001012 }
Rich Felkerf4f77c02012-10-05 13:09:09 -04001013 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
Rich Felker4ce3cb52012-02-06 14:39:09 -05001014}
1015
Rich Felker326e1262015-04-17 23:23:05 -04001016static void dl_debug_state(void)
Rich Felker3ec8d292012-04-25 00:05:42 -04001017{
1018}
1019
Rich Felker326e1262015-04-17 23:23:05 -04001020weak_alias(dl_debug_state, _dl_debug_state);
1021
Rich Felker7c6c2902013-08-03 16:27:30 -04001022void __reset_tls()
1023{
1024 pthread_t self = __pthread_self();
1025 struct dso *p;
1026 for (p=head; p; p=p->next) {
1027 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1028 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1029 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1030 p->tls_size - p->tls_len);
1031 if (p->tls_id == (size_t)self->dtv[0]) break;
1032 }
1033}
1034
Rich Felkerdcd60372012-10-05 11:51:50 -04001035void *__copy_tls(unsigned char *mem)
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001036{
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001037 pthread_t td;
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001038 struct dso *p;
Rich Felker0f66fce2015-04-13 18:07:10 -04001039 void **dtv;
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001040
Rich Felker9ec42832012-10-15 18:51:53 -04001041#ifdef TLS_ABOVE_TP
Rich Felker0f66fce2015-04-13 18:07:10 -04001042 dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1043
Rich Felker9ec42832012-10-15 18:51:53 -04001044 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1045 td = (pthread_t)mem;
1046 mem += sizeof(struct pthread);
1047
1048 for (p=head; p; p=p->next) {
1049 if (!p->tls_id) continue;
1050 dtv[p->tls_id] = mem + p->tls_offset;
1051 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1052 }
1053#else
Rich Felker0f66fce2015-04-13 18:07:10 -04001054 dtv = (void **)mem;
1055
Rich Felkere23d3582012-10-13 23:25:20 -04001056 mem += libc.tls_size - sizeof(struct pthread);
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001057 mem -= (uintptr_t)mem & (tls_align-1);
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001058 td = (pthread_t)mem;
1059
1060 for (p=head; p; p=p->next) {
Rich Felkerdcd60372012-10-05 11:51:50 -04001061 if (!p->tls_id) continue;
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001062 dtv[p->tls_id] = mem - p->tls_offset;
1063 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001064 }
Rich Felker9ec42832012-10-15 18:51:53 -04001065#endif
Rich Felker0f66fce2015-04-13 18:07:10 -04001066 dtv[0] = (void *)tls_cnt;
Szabolcs Nagy204a69d2015-03-11 12:48:12 +00001067 td->dtv = td->dtv_copy = dtv;
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001068 return td;
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001069}
1070
Rich Felkerbc081f62015-04-14 10:42:44 -04001071__attribute__((__visibility__("hidden")))
Rich Felker5ba238e2014-06-19 02:59:44 -04001072void *__tls_get_new(size_t *v)
Rich Felker9b153c02012-10-04 21:01:56 -04001073{
1074 pthread_t self = __pthread_self();
Rich Felkerdcd60372012-10-05 11:51:50 -04001075
1076 /* Block signals to make accessing new TLS async-signal-safe */
1077 sigset_t set;
Rich Felker5ba238e2014-06-19 02:59:44 -04001078 __block_all_sigs(&set);
Rich Felkere75b16c2014-06-19 02:16:57 -04001079 if (v[0]<=(size_t)self->dtv[0]) {
Rich Felker5ba238e2014-06-19 02:59:44 -04001080 __restore_sigs(&set);
Rich Felkerdcd60372012-10-05 11:51:50 -04001081 return (char *)self->dtv[v[0]]+v[1];
Rich Felker9b153c02012-10-04 21:01:56 -04001082 }
Rich Felkerdcd60372012-10-05 11:51:50 -04001083
1084 /* This is safe without any locks held because, if the caller
1085 * is able to request the Nth entry of the DTV, the DSO list
1086 * must be valid at least that far out and it was synchronized
1087 * at program startup or by an already-completed call to dlopen. */
1088 struct dso *p;
1089 for (p=head; p->tls_id != v[0]; p=p->next);
1090
1091 /* Get new DTV space from new DSO if needed */
Rich Felker44b4d092013-06-03 16:35:59 -04001092 if (v[0] > (size_t)self->dtv[0]) {
Rich Felkerdcd60372012-10-05 11:51:50 -04001093 void **newdtv = p->new_dtv +
1094 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
Rich Felker44b4d092013-06-03 16:35:59 -04001095 memcpy(newdtv, self->dtv,
Rich Felkerdcd60372012-10-05 11:51:50 -04001096 ((size_t)self->dtv[0]+1) * sizeof(void *));
1097 newdtv[0] = (void *)v[0];
Szabolcs Nagy204a69d2015-03-11 12:48:12 +00001098 self->dtv = self->dtv_copy = newdtv;
Rich Felkerdcd60372012-10-05 11:51:50 -04001099 }
1100
Rich Felkere75b16c2014-06-19 02:16:57 -04001101 /* Get new TLS memory from all new DSOs up to the requested one */
1102 unsigned char *mem;
1103 for (p=head; ; p=p->next) {
1104 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1105 mem = p->new_tls + (p->tls_size + p->tls_align)
1106 * a_fetch_add(&p->new_tls_idx,1);
1107 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1108 & (p->tls_align-1);
1109 self->dtv[p->tls_id] = mem;
1110 memcpy(mem, p->tls_image, p->tls_len);
1111 if (p->tls_id == v[0]) break;
1112 }
Rich Felker5ba238e2014-06-19 02:59:44 -04001113 __restore_sigs(&set);
Rich Felkerdcd60372012-10-05 11:51:50 -04001114 return mem + v[1];
Rich Felker9b153c02012-10-04 21:01:56 -04001115}
1116
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001117static void update_tls_size()
1118{
Rich Felker9ec42832012-10-15 18:51:53 -04001119 libc.tls_size = ALIGN(
1120 (1+tls_cnt) * sizeof(void *) +
1121 tls_offset +
1122 sizeof(struct pthread) +
1123 tls_align * 2,
1124 tls_align);
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001125}
1126
Rich Felkerf3ddd172015-04-13 02:56:26 -04001127/* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1128 * following stage 2 and stage 3 functions via primitive symbolic lookup
1129 * since it does not have access to their addresses to begin with. */
1130
1131/* Stage 2 of the dynamic linker is called after relative relocations
1132 * have been processed. It can make function calls to static functions
1133 * and access string literals and static data, but cannot use extern
1134 * symbols. Its job is to perform symbolic relocations on the dynamic
1135 * linker itself, but some of the relocations performed may need to be
1136 * replaced later due to copy relocations in the main program. */
1137
Rich Felker768b82c2015-05-25 19:15:17 -04001138void __dls2(unsigned char *base, size_t *sp)
Rich Felker51e2d832011-06-18 19:48:42 -04001139{
Rich Felkerf3ddd172015-04-13 02:56:26 -04001140 Ehdr *ehdr = (void *)base;
1141 ldso.base = base;
1142 ldso.name = ldso.shortname = "libc.so";
1143 ldso.global = 1;
1144 ldso.phnum = ehdr->e_phnum;
1145 ldso.phdr = (void *)(base + ehdr->e_phoff);
1146 ldso.phentsize = ehdr->e_phentsize;
Rich Felkerf3ddd172015-04-13 02:56:26 -04001147 kernel_mapped_dso(&ldso);
1148 decode_dyn(&ldso);
1149
Rich Felker9bbddf72015-05-25 23:33:59 -04001150 /* Prepare storage for to save clobbered REL addends so they
1151 * can be reused in stage 3. There should be very few. If
1152 * something goes wrong and there are a huge number, abort
1153 * instead of risking stack overflow. */
1154 size_t dyn[DYN_CNT];
1155 decode_vec(ldso.dynv, dyn, DYN_CNT);
1156 size_t *rel = (void *)(base+dyn[DT_REL]);
1157 size_t rel_size = dyn[DT_RELSZ];
1158 size_t symbolic_rel_cnt = 0;
1159 apply_addends_to = rel;
1160 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1161 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1162 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1163 size_t addends[symbolic_rel_cnt+1];
1164 saved_addends = addends;
1165
Rich Felkerf3ddd172015-04-13 02:56:26 -04001166 head = &ldso;
1167 reloc_all(&ldso);
1168
1169 ldso.relocated = 0;
Rich Felker768b82c2015-05-25 19:15:17 -04001170
1171 /* Call dynamic linker stage-3, __dls3, looking it up
1172 * symbolically as a barrier against moving the address
1173 * load across the above relocation processing. */
1174 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1175 ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
Rich Felkerf3ddd172015-04-13 02:56:26 -04001176}
1177
1178/* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1179 * fully functional. Its job is to load (if not already loaded) and
1180 * process dependencies and relocations for the main application and
1181 * transfer control to its entry point. */
1182
1183_Noreturn void __dls3(size_t *sp)
1184{
1185 static struct dso app, vdso;
Rich Felkerf4f95622015-04-13 22:38:18 -04001186 size_t aux[AUX_CNT], *auxv;
Rich Felker51e2d832011-06-18 19:48:42 -04001187 size_t i;
Rich Felker2719cc82011-08-16 00:24:36 -04001188 char *env_preload=0;
Rich Felkerdbcb3ad2012-08-25 17:31:59 -04001189 size_t vdso_base;
Rich Felkerf3ddd172015-04-13 02:56:26 -04001190 int argc = *sp;
1191 char **argv = (void *)(sp+1);
1192 char **argv_orig = argv;
Rich Felker75863602013-07-21 03:00:54 -04001193 char **envp = argv+argc+1;
Rich Felker71f099c2015-04-13 18:40:52 -04001194
1195 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1196 * use during dynamic linking. If possible it will also serve as the
1197 * thread pointer at runtime. */
1198 libc.tls_size = sizeof builtin_tls;
1199 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
Rich Felker19a1fe62015-04-13 19:24:51 -04001200 a_crash();
Rich Felker71f099c2015-04-13 18:40:52 -04001201 }
Rich Felker51e2d832011-06-18 19:48:42 -04001202
1203 /* Find aux vector just past environ[] */
Rich Felker568b8072011-06-25 01:56:34 -04001204 for (i=argc+1; argv[i]; i++)
1205 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
1206 env_path = argv[i]+16;
Rich Felker2719cc82011-08-16 00:24:36 -04001207 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
1208 env_preload = argv[i]+11;
Rich Felker51e2d832011-06-18 19:48:42 -04001209 auxv = (void *)(argv+i+1);
1210
1211 decode_vec(auxv, aux, AUX_CNT);
1212
Rich Felker568b8072011-06-25 01:56:34 -04001213 /* Only trust user/env if kernel says we're not suid/sgid */
1214 if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
Rich Felkera0458832011-08-16 07:46:42 -04001215 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
Rich Felker568b8072011-06-25 01:56:34 -04001216 env_path = 0;
Rich Felker2719cc82011-08-16 00:24:36 -04001217 env_preload = 0;
Rich Felkera897a202013-08-23 13:56:30 -04001218 libc.secure = 1;
Rich Felker568b8072011-06-25 01:56:34 -04001219 }
Szabolcs Nagyb20760c2013-09-15 02:00:32 +00001220 libc.page_size = aux[AT_PAGESZ];
Rich Felkerd8bdc972014-11-19 00:34:29 -05001221 libc.auxv = auxv;
Rich Felker568b8072011-06-25 01:56:34 -04001222
Rich Felkerf3ddd172015-04-13 02:56:26 -04001223 /* If the main program was already loaded by the kernel,
1224 * AT_PHDR will point to some location other than the dynamic
1225 * linker's program headers. */
1226 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
Rich Felker649cec52012-07-13 01:31:02 -04001227 size_t interp_off = 0;
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001228 size_t tls_image = 0;
Rich Felker5c1909a2012-05-27 16:01:44 -04001229 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
Rich Felkerf3ddd172015-04-13 02:56:26 -04001230 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1231 app.phnum = aux[AT_PHNUM];
1232 app.phentsize = aux[AT_PHENT];
Rich Felker5c1909a2012-05-27 16:01:44 -04001233 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1234 if (phdr->p_type == PT_PHDR)
Rich Felkerf3ddd172015-04-13 02:56:26 -04001235 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
Rich Felker649cec52012-07-13 01:31:02 -04001236 else if (phdr->p_type == PT_INTERP)
1237 interp_off = (size_t)phdr->p_vaddr;
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001238 else if (phdr->p_type == PT_TLS) {
1239 tls_image = phdr->p_vaddr;
Rich Felkerf3ddd172015-04-13 02:56:26 -04001240 app.tls_len = phdr->p_filesz;
1241 app.tls_size = phdr->p_memsz;
1242 app.tls_align = phdr->p_align;
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001243 }
Rich Felker5c1909a2012-05-27 16:01:44 -04001244 }
Rich Felkerf3ddd172015-04-13 02:56:26 -04001245 if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
1246 if (interp_off) ldso.name = (char *)app.base + interp_off;
Rich Felkercc515052013-08-23 14:14:47 -04001247 if ((aux[0] & (1UL<<AT_EXECFN))
1248 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
Rich Felkerf3ddd172015-04-13 02:56:26 -04001249 app.name = (char *)aux[AT_EXECFN];
Rich Felkercc515052013-08-23 14:14:47 -04001250 else
Rich Felkerf3ddd172015-04-13 02:56:26 -04001251 app.name = argv[0];
1252 kernel_mapped_dso(&app);
Rich Felker5c1909a2012-05-27 16:01:44 -04001253 } else {
1254 int fd;
1255 char *ldname = argv[0];
Rich Felkera617a8e2012-11-01 23:46:39 -04001256 size_t l = strlen(ldname);
Rich Felker5c1909a2012-05-27 16:01:44 -04001257 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
Rich Felkerf3ddd172015-04-13 02:56:26 -04001258 argv++;
Rich Felkerde451642014-04-16 12:45:36 -04001259 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1260 char *opt = argv[0]+2;
1261 *argv++ = (void *)-1;
1262 if (!*opt) {
1263 break;
1264 } else if (!memcmp(opt, "list", 5)) {
1265 ldd_mode = 1;
1266 } else if (!memcmp(opt, "library-path", 12)) {
1267 if (opt[12]=='=') env_path = opt+13;
1268 else if (opt[12]) *argv = 0;
1269 else if (*argv) env_path = *argv++;
1270 } else if (!memcmp(opt, "preload", 7)) {
1271 if (opt[7]=='=') env_preload = opt+8;
1272 else if (opt[7]) *argv = 0;
1273 else if (*argv) env_preload = *argv++;
1274 } else {
1275 argv[0] = 0;
1276 }
Rich Felkerde451642014-04-16 12:45:36 -04001277 }
Rich Felkerf3ddd172015-04-13 02:56:26 -04001278 argv[-1] = (void *)(argc - (argv-argv_orig));
Rich Felker5c1909a2012-05-27 16:01:44 -04001279 if (!argv[0]) {
Rich Felker179ab5a2013-12-01 17:27:25 -05001280 dprintf(2, "musl libc\n"
1281 "Version %s\n"
1282 "Dynamic Program Loader\n"
Rich Felkerde451642014-04-16 12:45:36 -04001283 "Usage: %s [options] [--] pathname%s\n",
Rich Felker179ab5a2013-12-01 17:27:25 -05001284 __libc_get_version(), ldname,
Rich Felker5c1909a2012-05-27 16:01:44 -04001285 ldd_mode ? "" : " [args]");
1286 _exit(1);
1287 }
1288 fd = open(argv[0], O_RDONLY);
1289 if (fd < 0) {
1290 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1291 _exit(1);
1292 }
1293 runtime = 1;
Rich Felkerf3ddd172015-04-13 02:56:26 -04001294 Ehdr *ehdr = (void *)map_library(fd, &app);
Rich Felker5c1909a2012-05-27 16:01:44 -04001295 if (!ehdr) {
1296 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1297 _exit(1);
1298 }
1299 runtime = 0;
1300 close(fd);
Rich Felkerf3ddd172015-04-13 02:56:26 -04001301 ldso.name = ldname;
1302 app.name = argv[0];
1303 aux[AT_ENTRY] = (size_t)app.base + ehdr->e_entry;
Rich Felkera97a0502013-07-26 14:41:12 -04001304 /* Find the name that would have been used for the dynamic
1305 * linker had ldd not taken its place. */
1306 if (ldd_mode) {
Rich Felkerf3ddd172015-04-13 02:56:26 -04001307 for (i=0; i<app.phnum; i++) {
1308 if (app.phdr[i].p_type == PT_INTERP)
1309 ldso.name = (void *)(app.base
1310 + app.phdr[i].p_vaddr);
Rich Felkera97a0502013-07-26 14:41:12 -04001311 }
Rich Felkerf3ddd172015-04-13 02:56:26 -04001312 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
Rich Felkera97a0502013-07-26 14:41:12 -04001313 }
Rich Felkere12fe652012-01-23 02:02:59 -05001314 }
Rich Felkerf3ddd172015-04-13 02:56:26 -04001315 if (app.tls_size) {
1316 app.tls_id = tls_cnt = 1;
Rich Felker9ec42832012-10-15 18:51:53 -04001317#ifdef TLS_ABOVE_TP
Rich Felkerf3ddd172015-04-13 02:56:26 -04001318 app.tls_offset = 0;
1319 tls_offset = app.tls_size
1320 + ( -((uintptr_t)app.tls_image + app.tls_size)
1321 & (app.tls_align-1) );
Rich Felker9ec42832012-10-15 18:51:53 -04001322#else
Rich Felkerf3ddd172015-04-13 02:56:26 -04001323 tls_offset = app.tls_offset = app.tls_size
1324 + ( -((uintptr_t)app.tls_image + app.tls_size)
1325 & (app.tls_align-1) );
Rich Felker9ec42832012-10-15 18:51:53 -04001326#endif
Rich Felkerf3ddd172015-04-13 02:56:26 -04001327 tls_align = MAXP2(tls_align, app.tls_align);
Rich Felkerbc6a35f2012-10-04 20:04:13 -04001328 }
Rich Felkerf3ddd172015-04-13 02:56:26 -04001329 app.global = 1;
1330 decode_dyn(&app);
Rich Felkerc82f4a32012-01-23 00:57:38 -05001331
1332 /* Attach to vdso, if provided by the kernel */
Rich Felkerdbcb3ad2012-08-25 17:31:59 -04001333 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
Rich Felkerf3ddd172015-04-13 02:56:26 -04001334 Ehdr *ehdr = (void *)vdso_base;
1335 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1336 vdso.phnum = ehdr->e_phnum;
1337 vdso.phentsize = ehdr->e_phentsize;
Rich Felker6ab444d2011-07-24 00:54:55 -04001338 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1339 if (phdr->p_type == PT_DYNAMIC)
Rich Felkerf3ddd172015-04-13 02:56:26 -04001340 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
Rich Felker6ab444d2011-07-24 00:54:55 -04001341 if (phdr->p_type == PT_LOAD)
Rich Felkerf3ddd172015-04-13 02:56:26 -04001342 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
Rich Felker6ab444d2011-07-24 00:54:55 -04001343 }
Rich Felkerf3ddd172015-04-13 02:56:26 -04001344 vdso.name = "";
1345 vdso.shortname = "linux-gate.so.1";
1346 vdso.global = 1;
1347 vdso.relocated = 1;
1348 decode_dyn(&vdso);
1349 vdso.prev = &ldso;
1350 ldso.next = &vdso;
Rich Felker6ab444d2011-07-24 00:54:55 -04001351 }
1352
Rich Felkerf3ddd172015-04-13 02:56:26 -04001353 /* Initial dso chain consists only of the app. */
1354 head = tail = &app;
Rich Felker51e2d832011-06-18 19:48:42 -04001355
Rich Felkerc82f4a32012-01-23 00:57:38 -05001356 /* Donate unused parts of app and library mapping to malloc */
Rich Felkerf3ddd172015-04-13 02:56:26 -04001357 reclaim_gaps(&app);
1358 reclaim_gaps(&ldso);
Rich Felker6717e622011-06-28 19:40:14 -04001359
Rich Felkerc82f4a32012-01-23 00:57:38 -05001360 /* Load preload/needed libraries, add their symbols to the global
Rich Felkerf3ddd172015-04-13 02:56:26 -04001361 * namespace, and perform all remaining relocations. */
Rich Felker2719cc82011-08-16 00:24:36 -04001362 if (env_preload) load_preload(env_preload);
Rich Felkerf3ddd172015-04-13 02:56:26 -04001363 load_deps(&app);
1364 make_global(&app);
Rich Felker9c748562012-10-04 22:48:33 -04001365
Timo Teräse13a2b82014-03-25 14:13:27 +02001366#ifndef DYNAMIC_IS_RO
Rich Felkerf3ddd172015-04-13 02:56:26 -04001367 for (i=0; app.dynv[i]; i+=2)
1368 if (app.dynv[i]==DT_DEBUG)
1369 app.dynv[i+1] = (size_t)&debug;
Timo Teräse13a2b82014-03-25 14:13:27 +02001370#endif
1371
Rich Felkerf3ddd172015-04-13 02:56:26 -04001372 /* The main program must be relocated LAST since it may contin
1373 * copy relocations which depend on libraries' relocations. */
1374 reloc_all(app.next);
1375 reloc_all(&app);
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001376
1377 update_tls_size();
Rich Felker71f099c2015-04-13 18:40:52 -04001378 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1379 void *initial_tls = calloc(libc.tls_size, 1);
Rich Felkerdab441a2014-03-24 16:57:11 -04001380 if (!initial_tls) {
Rich Felker9c748562012-10-04 22:48:33 -04001381 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
Rich Felkere23d3582012-10-13 23:25:20 -04001382 argv[0], libc.tls_size);
Rich Felker9c748562012-10-04 22:48:33 -04001383 _exit(127);
1384 }
Rich Felker71f099c2015-04-13 18:40:52 -04001385 if (__init_tp(__copy_tls(initial_tls)) < 0) {
Rich Felker19a1fe62015-04-13 19:24:51 -04001386 a_crash();
Rich Felker71f099c2015-04-13 18:40:52 -04001387 }
Rich Felkerdab441a2014-03-24 16:57:11 -04001388 } else {
Rich Felker71f099c2015-04-13 18:40:52 -04001389 size_t tmp_tls_size = libc.tls_size;
1390 pthread_t self = __pthread_self();
1391 /* Temporarily set the tls size to the full size of
1392 * builtin_tls so that __copy_tls will use the same layout
1393 * as it did for before. Then check, just to be safe. */
1394 libc.tls_size = sizeof builtin_tls;
1395 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1396 libc.tls_size = tmp_tls_size;
Rich Felker9c748562012-10-04 22:48:33 -04001397 }
Rich Felker9d15d5e2014-06-19 02:01:06 -04001398 static_tls_cnt = tls_cnt;
Rich Felker9c748562012-10-04 22:48:33 -04001399
Rich Felker04109502012-08-18 16:00:23 -04001400 if (ldso_fail) _exit(127);
Rich Felker5c1909a2012-05-27 16:01:44 -04001401 if (ldd_mode) _exit(0);
1402
Rich Felkerc82f4a32012-01-23 00:57:38 -05001403 /* Switch to runtime mode: any further failures in the dynamic
1404 * linker are a reportable failure rather than a fatal startup
Rich Felkerf3ddd172015-04-13 02:56:26 -04001405 * error. */
Rich Felkera53de812011-07-24 00:26:12 -04001406 runtime = 1;
Rich Felker4ce3cb52012-02-06 14:39:09 -05001407
Rich Felker3ec8d292012-04-25 00:05:42 -04001408 debug.ver = 1;
Rich Felker326e1262015-04-17 23:23:05 -04001409 debug.bp = dl_debug_state;
Rich Felker3ec8d292012-04-25 00:05:42 -04001410 debug.head = head;
Rich Felkerf3ddd172015-04-13 02:56:26 -04001411 debug.base = ldso.base;
Rich Felker3ec8d292012-04-25 00:05:42 -04001412 debug.state = 0;
1413 _dl_debug_state();
1414
Rich Felker75863602013-07-21 03:00:54 -04001415 __init_libc(envp, argv[0]);
Rich Felkera7936f62012-11-30 17:56:23 -05001416 atexit(do_fini);
Rich Felker75863602013-07-21 03:00:54 -04001417 errno = 0;
Rich Felkera7936f62012-11-30 17:56:23 -05001418 do_init_fini(tail);
Rich Felker75863602013-07-21 03:00:54 -04001419
Rich Felkerf3ddd172015-04-13 02:56:26 -04001420 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1421 for(;;);
Rich Felkera7936f62012-11-30 17:56:23 -05001422}
1423
Rich Felker59ab43f2011-06-26 19:23:28 -04001424void *dlopen(const char *file, int mode)
1425{
Rich Felker642b7592012-10-05 01:15:25 -04001426 struct dso *volatile p, *orig_tail, *next;
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001427 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
Rich Felker59ab43f2011-06-26 19:23:28 -04001428 size_t i;
Rich Felkerf2baf4d2012-02-07 20:31:27 -05001429 int cs;
Rich Felker17276be2013-07-24 02:38:05 -04001430 jmp_buf jb;
Rich Felker59ab43f2011-06-26 19:23:28 -04001431
1432 if (!file) return head;
1433
Rich Felkerf2baf4d2012-02-07 20:31:27 -05001434 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
Rich Felker59ab43f2011-06-26 19:23:28 -04001435 pthread_rwlock_wrlock(&lock);
Rich Felkerdcd60372012-10-05 11:51:50 -04001436 __inhibit_ptc();
Rich Felker59ab43f2011-06-26 19:23:28 -04001437
Rich Felkerdcd60372012-10-05 11:51:50 -04001438 p = 0;
1439 orig_tls_cnt = tls_cnt;
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001440 orig_tls_offset = tls_offset;
1441 orig_tls_align = tls_align;
Rich Felker642b7592012-10-05 01:15:25 -04001442 orig_tail = tail;
Rich Felker4d07e552013-01-23 22:07:45 -05001443 noload = mode & RTLD_NOLOAD;
Rich Felker642b7592012-10-05 01:15:25 -04001444
Rich Felker17276be2013-07-24 02:38:05 -04001445 rtld_fail = &jb;
1446 if (setjmp(*rtld_fail)) {
Rich Felker59ab43f2011-06-26 19:23:28 -04001447 /* Clean up anything new that was (partially) loaded */
Rich Felkerdcd60372012-10-05 11:51:50 -04001448 if (p && p->deps) for (i=0; p->deps[i]; i++)
Rich Felker92ab5d82011-06-26 21:21:04 -04001449 if (p->deps[i]->global < 0)
1450 p->deps[i]->global = 0;
Rich Felker59ab43f2011-06-26 19:23:28 -04001451 for (p=orig_tail->next; p; p=next) {
1452 next = p->next;
1453 munmap(p->map, p->map_len);
Rich Felker9d15d5e2014-06-19 02:01:06 -04001454 while (p->td_index) {
1455 void *tmp = p->td_index->next;
1456 free(p->td_index);
1457 p->td_index = tmp;
1458 }
Rich Felker07709622015-04-04 00:15:19 -04001459 if (p->rpath != p->rpath_orig)
1460 free(p->rpath);
Rich Felker59ab43f2011-06-26 19:23:28 -04001461 free(p->deps);
1462 free(p);
1463 }
Rich Felkerdcd60372012-10-05 11:51:50 -04001464 tls_cnt = orig_tls_cnt;
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001465 tls_offset = orig_tls_offset;
1466 tls_align = orig_tls_align;
Rich Felker59ab43f2011-06-26 19:23:28 -04001467 tail = orig_tail;
1468 tail->next = 0;
Rich Felkerf2baf4d2012-02-07 20:31:27 -05001469 p = 0;
Rich Felkera5d10eb2012-04-23 12:03:31 -04001470 goto end;
Rich Felker0f9b1f62013-08-23 23:13:25 -04001471 } else p = load_library(file, head);
Rich Felkera9e85c02012-03-23 00:28:20 -04001472
1473 if (!p) {
Rich Felker01d42742015-04-18 18:00:22 -04001474 error(noload ?
Rich Felker4d07e552013-01-23 22:07:45 -05001475 "Library %s is not already loaded" :
1476 "Error loading shared library %s: %m",
1477 file);
Rich Felkerf2baf4d2012-02-07 20:31:27 -05001478 goto end;
Rich Felker59ab43f2011-06-26 19:23:28 -04001479 }
1480
Rich Felker59ab43f2011-06-26 19:23:28 -04001481 /* First load handling */
1482 if (!p->deps) {
1483 load_deps(p);
Rich Felker0e4dae32011-06-26 21:36:44 -04001484 if (p->deps) for (i=0; p->deps[i]; i++)
Rich Felker92ab5d82011-06-26 21:21:04 -04001485 if (!p->deps[i]->global)
1486 p->deps[i]->global = -1;
1487 if (!p->global) p->global = -1;
Rich Felker59ab43f2011-06-26 19:23:28 -04001488 reloc_all(p);
Rich Felker0e4dae32011-06-26 21:36:44 -04001489 if (p->deps) for (i=0; p->deps[i]; i++)
Rich Felker92ab5d82011-06-26 21:21:04 -04001490 if (p->deps[i]->global < 0)
1491 p->deps[i]->global = 0;
1492 if (p->global < 0) p->global = 0;
Rich Felker59ab43f2011-06-26 19:23:28 -04001493 }
1494
1495 if (mode & RTLD_GLOBAL) {
Rich Felker0e4dae32011-06-26 21:36:44 -04001496 if (p->deps) for (i=0; p->deps[i]; i++)
Rich Felker59ab43f2011-06-26 19:23:28 -04001497 p->deps[i]->global = 1;
1498 p->global = 1;
1499 }
1500
Rich Felkercf3fd3d2012-10-06 01:22:51 -04001501 update_tls_size();
Rich Felker3ec8d292012-04-25 00:05:42 -04001502 _dl_debug_state();
Rich Felkerf4f77c02012-10-05 13:09:09 -04001503 orig_tail = tail;
Rich Felker06933cc2011-06-26 22:09:32 -04001504end:
Rich Felkerdcd60372012-10-05 11:51:50 -04001505 __release_ptc();
Rich Felker18c0e022012-10-31 21:27:48 -04001506 if (p) gencnt++;
Rich Felker59ab43f2011-06-26 19:23:28 -04001507 pthread_rwlock_unlock(&lock);
Rich Felkerf4f77c02012-10-05 13:09:09 -04001508 if (p) do_init_fini(orig_tail);
Rich Felkerf2baf4d2012-02-07 20:31:27 -05001509 pthread_setcancelstate(cs, 0);
Rich Felker59ab43f2011-06-26 19:23:28 -04001510 return p;
1511}
1512
Rich Felker4d982802013-01-16 11:49:00 -05001513static int invalid_dso_handle(void *h)
Rich Felker6468fc92013-01-10 14:05:40 -05001514{
1515 struct dso *p;
1516 for (p=head; p; p=p->next) if (h==p) return 0;
Rich Felker01d42742015-04-18 18:00:22 -04001517 error("Invalid library handle %p", (void *)h);
Rich Felker6468fc92013-01-10 14:05:40 -05001518 return 1;
1519}
1520
Rich Felker5ba238e2014-06-19 02:59:44 -04001521void *__tls_get_addr(size_t *);
1522
Rich Felker623753a2011-08-16 00:42:13 -04001523static void *do_dlsym(struct dso *p, const char *s, void *ra)
Rich Felker59ab43f2011-06-26 19:23:28 -04001524{
1525 size_t i;
Rich Felker2bd05a42012-08-25 17:13:28 -04001526 uint32_t h = 0, gh = 0;
Rich Felker59ab43f2011-06-26 19:23:28 -04001527 Sym *sym;
Rich Felker9c748562012-10-04 22:48:33 -04001528 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
Rich Felkerdeb15b32012-10-19 21:41:30 -04001529 if (p == RTLD_DEFAULT) {
1530 p = head;
1531 } else if (p == RTLD_NEXT) {
Rich Felker9c748562012-10-04 22:48:33 -04001532 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1533 if (!p) p=head;
Rich Felkerdeb15b32012-10-19 21:41:30 -04001534 p = p->next;
Rich Felker9c748562012-10-04 22:48:33 -04001535 }
Rich Felkerdeb15b32012-10-19 21:41:30 -04001536 struct symdef def = find_sym(p, s, 0);
Rich Felker9c748562012-10-04 22:48:33 -04001537 if (!def.sym) goto failed;
Rich Felker0a1c2c12012-10-19 21:57:56 -04001538 if ((def.sym->st_info&0xf) == STT_TLS)
1539 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
Rich Felker9c748562012-10-04 22:48:33 -04001540 return def.dso->base + def.sym->st_value;
Rich Felkera9e85c02012-03-23 00:28:20 -04001541 }
Rich Felker97b72d22015-04-21 13:07:06 -04001542 if (invalid_dso_handle(p))
Rich Felker637dd2d2013-01-23 20:21:36 -05001543 return 0;
Rich Felker2bd05a42012-08-25 17:13:28 -04001544 if (p->ghashtab) {
1545 gh = gnu_hash(s);
1546 sym = gnu_lookup(s, gh, p);
1547 } else {
1548 h = sysv_hash(s);
1549 sym = sysv_lookup(s, h, p);
1550 }
Rich Felker0a1c2c12012-10-19 21:57:56 -04001551 if (sym && (sym->st_info&0xf) == STT_TLS)
1552 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
Rich Felker59ab43f2011-06-26 19:23:28 -04001553 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1554 return p->base + sym->st_value;
1555 if (p->deps) for (i=0; p->deps[i]; i++) {
Rich Felker2bd05a42012-08-25 17:13:28 -04001556 if (p->deps[i]->ghashtab) {
1557 if (!gh) gh = gnu_hash(s);
Rich Felkera5d61992012-08-25 17:40:27 -04001558 sym = gnu_lookup(s, gh, p->deps[i]);
Rich Felker2bd05a42012-08-25 17:13:28 -04001559 } else {
1560 if (!h) h = sysv_hash(s);
1561 sym = sysv_lookup(s, h, p->deps[i]);
1562 }
Rich Felker0a1c2c12012-10-19 21:57:56 -04001563 if (sym && (sym->st_info&0xf) == STT_TLS)
1564 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
Rich Felker59ab43f2011-06-26 19:23:28 -04001565 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1566 return p->deps[i]->base + sym->st_value;
1567 }
Rich Felker4027f4e2012-05-04 20:18:18 -04001568failed:
Rich Felker01d42742015-04-18 18:00:22 -04001569 error("Symbol not found: %s", s);
Rich Felker59ab43f2011-06-26 19:23:28 -04001570 return 0;
1571}
1572
Rich Felker839cc4e2014-01-06 22:03:38 -05001573int __dladdr(const void *addr, Dl_info *info)
Rich Felkerf419bcb2012-08-26 21:09:26 -04001574{
1575 struct dso *p;
1576 Sym *sym;
1577 uint32_t nsym;
1578 char *strings;
1579 size_t i;
1580 void *best = 0;
1581 char *bestname;
1582
1583 pthread_rwlock_rdlock(&lock);
1584 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1585 pthread_rwlock_unlock(&lock);
1586
1587 if (!p) return 0;
1588
1589 sym = p->syms;
1590 strings = p->strings;
1591 if (p->hashtab) {
1592 nsym = p->hashtab[1];
1593 } else {
1594 uint32_t *buckets;
1595 uint32_t *hashval;
1596 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1597 sym += p->ghashtab[1];
Rich Felker78869852013-10-04 00:29:58 -04001598 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
Rich Felkerf419bcb2012-08-26 21:09:26 -04001599 if (buckets[i] > nsym)
1600 nsym = buckets[i];
1601 }
1602 if (nsym) {
1603 nsym -= p->ghashtab[1];
1604 hashval = buckets + p->ghashtab[0] + nsym;
1605 do nsym++;
1606 while (!(*hashval++ & 1));
1607 }
1608 }
1609
1610 for (; nsym; nsym--, sym++) {
Rich Felkercdc5c742013-01-16 11:47:35 -05001611 if (sym->st_value
Rich Felkerf419bcb2012-08-26 21:09:26 -04001612 && (1<<(sym->st_info&0xf) & OK_TYPES)
1613 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1614 void *symaddr = p->base + sym->st_value;
1615 if (symaddr > addr || symaddr < best)
1616 continue;
1617 best = symaddr;
1618 bestname = strings + sym->st_name;
1619 if (addr == symaddr)
1620 break;
1621 }
1622 }
1623
1624 if (!best) return 0;
1625
1626 info->dli_fname = p->name;
1627 info->dli_fbase = p->base;
1628 info->dli_sname = bestname;
1629 info->dli_saddr = best;
1630
1631 return 1;
1632}
1633
Rich Felker72b25dd2015-04-14 11:39:11 -04001634__attribute__((__visibility__("hidden")))
Rich Felker400c5e52012-09-06 22:44:55 -04001635void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
Rich Felker59ab43f2011-06-26 19:23:28 -04001636{
1637 void *res;
1638 pthread_rwlock_rdlock(&lock);
Rich Felker623753a2011-08-16 00:42:13 -04001639 res = do_dlsym(p, s, ra);
Rich Felker59ab43f2011-06-26 19:23:28 -04001640 pthread_rwlock_unlock(&lock);
1641 return res;
1642}
Rich Felker18c0e022012-10-31 21:27:48 -04001643
1644int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1645{
1646 struct dso *current;
1647 struct dl_phdr_info info;
1648 int ret = 0;
1649 for(current = head; current;) {
1650 info.dlpi_addr = (uintptr_t)current->base;
1651 info.dlpi_name = current->name;
1652 info.dlpi_phdr = current->phdr;
1653 info.dlpi_phnum = current->phnum;
1654 info.dlpi_adds = gencnt;
1655 info.dlpi_subs = 0;
1656 info.dlpi_tls_modid = current->tls_id;
1657 info.dlpi_tls_data = current->tls_image;
1658
1659 ret = (callback)(&info, sizeof (info), data);
1660
1661 if (ret != 0) break;
1662
1663 pthread_rwlock_rdlock(&lock);
1664 current = current->next;
1665 pthread_rwlock_unlock(&lock);
1666 }
1667 return ret;
1668}
Rich Felker5a09a532012-02-03 03:16:07 -05001669#else
Rich Felker4d982802013-01-16 11:49:00 -05001670static int invalid_dso_handle(void *h)
Rich Felker6468fc92013-01-10 14:05:40 -05001671{
Rich Felker01d42742015-04-18 18:00:22 -04001672 error("Invalid library handle %p", (void *)h);
Rich Felker6468fc92013-01-10 14:05:40 -05001673 return 1;
1674}
Rich Felker5a09a532012-02-03 03:16:07 -05001675void *dlopen(const char *file, int mode)
1676{
Rich Felker01d42742015-04-18 18:00:22 -04001677 error("Dynamic loading not supported");
Rich Felker5a09a532012-02-03 03:16:07 -05001678 return 0;
1679}
Rich Felker400c5e52012-09-06 22:44:55 -04001680void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
Rich Felker5a09a532012-02-03 03:16:07 -05001681{
Rich Felker01d42742015-04-18 18:00:22 -04001682 error("Symbol not found: %s", s);
Rich Felker5a09a532012-02-03 03:16:07 -05001683 return 0;
1684}
Rich Felker839cc4e2014-01-06 22:03:38 -05001685int __dladdr (const void *addr, Dl_info *info)
Rich Felkerf419bcb2012-08-26 21:09:26 -04001686{
1687 return 0;
1688}
Rich Felker5a09a532012-02-03 03:16:07 -05001689#endif
Rich Felker59ab43f2011-06-26 19:23:28 -04001690
Rich Felker780cbbe2013-06-29 12:46:46 -04001691int __dlinfo(void *dso, int req, void *res)
1692{
1693 if (invalid_dso_handle(dso)) return -1;
1694 if (req != RTLD_DI_LINKMAP) {
Rich Felker01d42742015-04-18 18:00:22 -04001695 error("Unsupported request %d", req);
Rich Felker780cbbe2013-06-29 12:46:46 -04001696 return -1;
1697 }
1698 *(struct link_map **)res = dso;
1699 return 0;
1700}
1701
Rich Felker59ab43f2011-06-26 19:23:28 -04001702char *dlerror()
1703{
Rich Felker01d42742015-04-18 18:00:22 -04001704 pthread_t self = __pthread_self();
1705 if (!self->dlerror_flag) return 0;
1706 self->dlerror_flag = 0;
1707 char *s = self->dlerror_buf;
1708 if (s == (void *)-1)
1709 return "Dynamic linker failed to allocate memory for error message";
1710 else
1711 return s;
Rich Felker59ab43f2011-06-26 19:23:28 -04001712}
1713
1714int dlclose(void *p)
1715{
Rich Felker6468fc92013-01-10 14:05:40 -05001716 return invalid_dso_handle(p);
Rich Felker59ab43f2011-06-26 19:23:28 -04001717}
Rich Felker01d42742015-04-18 18:00:22 -04001718
1719void __dl_thread_cleanup(void)
1720{
1721 pthread_t self = __pthread_self();
1722 if (self->dlerror_buf != (void *)-1)
1723 free(self->dlerror_buf);
1724}
1725
1726static void error(const char *fmt, ...)
1727{
1728 va_list ap;
1729 va_start(ap, fmt);
1730#ifdef SHARED
1731 if (!runtime) {
1732 vdprintf(2, fmt, ap);
1733 dprintf(2, "\n");
1734 ldso_fail = 1;
1735 va_end(ap);
1736 return;
1737 }
1738#endif
1739 pthread_t self = __pthread_self();
1740 if (self->dlerror_buf != (void *)-1)
1741 free(self->dlerror_buf);
1742 size_t len = vsnprintf(0, 0, fmt, ap);
1743 va_end(ap);
1744 char *buf = malloc(len+1);
1745 if (buf) {
1746 va_start(ap, fmt);
1747 vsnprintf(buf, len+1, fmt, ap);
1748 va_end(ap);
1749 } else {
1750 buf = (void *)-1;
1751 }
1752 self->dlerror_buf = buf;
1753 self->dlerror_flag = 1;
1754}