2 #define SYSCALL_NO_TLS 1
21 #include <semaphore.h>
22 #include <sys/membarrier.h>
23 #include "pthread_impl.h"
27 static void error(const char *, ...);
29 #define MAXP2(a,b) (-(-(a)&-(b)))
30 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
32 #define container_of(p,t,m) ((t*)((char *)(p)-offsetof(t,m)))
33 #define countof(a) ((sizeof (a))/(sizeof (a)[0]))
45 struct td_index
*next
;
50 struct fdpic_loadmap
*loadmap
;
56 struct dso
*next
, *prev
;
66 struct dso
*syms_next
, *lazy_next
;
67 size_t *lazy
, lazy_cnt
;
78 struct dso
**deps
, *needed_by
;
82 char *rpath_orig
, *rpath
;
83 struct tls_module tls
;
85 size_t relro_start
, relro_end
;
87 unsigned char *new_tls
;
88 struct td_index
*td_index
;
89 struct dso
*fini_next
;
94 struct fdpic_loadmap
*loadmap
;
109 typedef void (*stage3_func
)(size_t *, size_t *);
111 static struct builtin_tls
{
116 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
118 #define ADDEND_LIMIT 4096
119 static size_t *saved_addends
, *apply_addends_to
;
121 static struct dso ldso
;
122 static struct dso
*head
, *tail
, *fini_head
, *syms_tail
, *lazy_head
;
123 static char *env_path
, *sys_path
;
124 static unsigned long long gencnt
;
127 static int ldso_fail
;
129 static int shutting_down
;
130 static jmp_buf *rtld_fail
;
131 static pthread_rwlock_t lock
;
132 static struct debug debug
;
133 static struct tls_module
*tls_tail
;
134 static size_t tls_cnt
, tls_offset
, tls_align
= MIN_TLS_ALIGN
;
135 static size_t static_tls_cnt
;
136 static pthread_mutex_t init_fini_lock
;
137 static pthread_cond_t ctor_cond
;
138 static struct dso
*builtin_deps
[2];
139 static struct dso
*const no_deps
[1];
140 static struct dso
*builtin_ctor_queue
[4];
141 static struct dso
**main_ctor_queue
;
142 static struct fdpic_loadmap
*app_loadmap
;
143 static struct fdpic_dummy_loadmap app_dummy_loadmap
;
145 struct debug
*_dl_debug_addr
= &debug
;
147 extern hidden
int __malloc_replaced
;
149 hidden
void (*const __init_array_start
)(void)=0, (*const __fini_array_start
)(void)=0;
151 extern hidden
void (*const __init_array_end
)(void), (*const __fini_array_end
)(void);
153 weak_alias(__init_array_start
, __init_array_end
);
154 weak_alias(__fini_array_start
, __fini_array_end
);
156 static int dl_strcmp(const char *l
, const char *r
)
158 for (; *l
==*r
&& *l
; l
++, r
++);
159 return *(unsigned char *)l
- *(unsigned char *)r
;
161 #define strcmp(l,r) dl_strcmp(l,r)
163 /* Compute load address for a virtual address in a given dso. */
165 static void *laddr(const struct dso
*p
, size_t v
)
168 if (!p
->loadmap
) return p
->base
+ v
;
169 for (j
=0; v
-p
->loadmap
->segs
[j
].p_vaddr
>= p
->loadmap
->segs
[j
].p_memsz
; j
++);
170 return (void *)(v
- p
->loadmap
->segs
[j
].p_vaddr
+ p
->loadmap
->segs
[j
].addr
);
172 static void *laddr_pg(const struct dso
*p
, size_t v
)
175 size_t pgsz
= PAGE_SIZE
;
176 if (!p
->loadmap
) return p
->base
+ v
;
178 size_t a
= p
->loadmap
->segs
[j
].p_vaddr
;
179 size_t b
= a
+ p
->loadmap
->segs
[j
].p_memsz
;
185 return (void *)(v
- p
->loadmap
->segs
[j
].p_vaddr
+ p
->loadmap
->segs
[j
].addr
);
187 static void (*fdbarrier(void *p
))()
190 __asm__("" : "=r"(fd
) : "0"(p
));
193 #define fpaddr(p, v) fdbarrier((&(struct funcdesc){ \
194 laddr(p, v), (p)->got }))
196 #define laddr(p, v) (void *)((p)->base + (v))
197 #define laddr_pg(p, v) laddr(p, v)
198 #define fpaddr(p, v) ((void (*)())laddr(p, v))
201 static void decode_vec(size_t *v
, size_t *a
, size_t cnt
)
204 for (i
=0; i
<cnt
; i
++) a
[i
] = 0;
205 for (; v
[0]; v
+=2) if (v
[0]-1<cnt
-1) {
211 static int search_vec(size_t *v
, size_t *r
, size_t key
)
213 for (; v
[0]!=key
; v
+=2)
219 static uint32_t sysv_hash(const char *s0
)
221 const unsigned char *s
= (void *)s0
;
227 return h
& 0xfffffff;
230 static uint32_t gnu_hash(const char *s0
)
232 const unsigned char *s
= (void *)s0
;
233 uint_fast32_t h
= 5381;
239 static Sym
*sysv_lookup(const char *s
, uint32_t h
, struct dso
*dso
)
242 Sym
*syms
= dso
->syms
;
243 Elf_Symndx
*hashtab
= dso
->hashtab
;
244 char *strings
= dso
->strings
;
245 for (i
=hashtab
[2+h
%hashtab
[0]]; i
; i
=hashtab
[2+hashtab
[0]+i
]) {
246 if ((!dso
->versym
|| dso
->versym
[i
] >= 0)
247 && (!strcmp(s
, strings
+syms
[i
].st_name
)))
253 static Sym
*gnu_lookup(uint32_t h1
, uint32_t *hashtab
, struct dso
*dso
, const char *s
)
255 uint32_t nbuckets
= hashtab
[0];
256 uint32_t *buckets
= hashtab
+ 4 + hashtab
[2]*(sizeof(size_t)/4);
257 uint32_t i
= buckets
[h1
% nbuckets
];
261 uint32_t *hashval
= buckets
+ nbuckets
+ (i
- hashtab
[1]);
263 for (h1
|= 1; ; i
++) {
264 uint32_t h2
= *hashval
++;
265 if ((h1
== (h2
|1)) && (!dso
->versym
|| dso
->versym
[i
] >= 0)
266 && !strcmp(s
, dso
->strings
+ dso
->syms
[i
].st_name
))
274 static Sym
*gnu_lookup_filtered(uint32_t h1
, uint32_t *hashtab
, struct dso
*dso
, const char *s
, uint32_t fofs
, size_t fmask
)
276 const size_t *bloomwords
= (const void *)(hashtab
+4);
277 size_t f
= bloomwords
[fofs
& (hashtab
[2]-1)];
278 if (!(f
& fmask
)) return 0;
280 f
>>= (h1
>> hashtab
[3]) % (8 * sizeof f
);
281 if (!(f
& 1)) return 0;
283 return gnu_lookup(h1
, hashtab
, dso
, s
);
286 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
287 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
289 #ifndef ARCH_SYM_REJECT_UND
290 #define ARCH_SYM_REJECT_UND(s) 0
293 #if defined(__GNUC__)
294 __attribute__((always_inline
))
296 static inline struct symdef
find_sym2(struct dso
*dso
, const char *s
, int need_def
, int use_deps
)
298 uint32_t h
= 0, gh
= gnu_hash(s
), gho
= gh
/ (8*sizeof(size_t)), *ght
;
299 size_t ghm
= 1ul << gh
% (8*sizeof(size_t));
300 struct symdef def
= {0};
301 struct dso
**deps
= use_deps
? dso
->deps
: 0;
302 for (; dso
; dso
=use_deps
? *deps
++ : dso
->syms_next
) {
304 if ((ght
= dso
->ghashtab
)) {
305 sym
= gnu_lookup_filtered(gh
, ght
, dso
, s
, gho
, ghm
);
307 if (!h
) h
= sysv_hash(s
);
308 sym
= sysv_lookup(s
, h
, dso
);
312 if (need_def
|| (sym
->st_info
&0xf) == STT_TLS
313 || ARCH_SYM_REJECT_UND(sym
))
316 if ((sym
->st_info
&0xf) != STT_TLS
)
318 if (!(1<<(sym
->st_info
&0xf) & OK_TYPES
)) continue;
319 if (!(1<<(sym
->st_info
>>4) & OK_BINDS
)) continue;
327 static struct symdef
find_sym(struct dso
*dso
, const char *s
, int need_def
)
329 return find_sym2(dso
, s
, need_def
, 0);
332 static void do_relocs(struct dso
*dso
, size_t *rel
, size_t rel_size
, size_t stride
)
334 unsigned char *base
= dso
->base
;
335 Sym
*syms
= dso
->syms
;
336 char *strings
= dso
->strings
;
347 int skip_relative
= 0, reuse_addends
= 0, save_slot
= 0;
350 /* Only ldso's REL table needs addend saving/reuse. */
351 if (rel
== apply_addends_to
)
356 for (; rel_size
; rel
+=stride
, rel_size
-=stride
*sizeof(size_t)) {
357 if (skip_relative
&& IS_RELATIVE(rel
[1], dso
->syms
)) continue;
358 type
= R_TYPE(rel
[1]);
359 if (type
== REL_NONE
) continue;
360 reloc_addr
= laddr(dso
, rel
[0]);
364 } else if (type
==REL_GOT
|| type
==REL_PLT
|| type
==REL_COPY
) {
366 } else if (reuse_addends
) {
367 /* Save original addend in stage 2 where the dso
368 * chain consists of just ldso; otherwise read back
369 * saved addend since the inline one was clobbered. */
371 saved_addends
[save_slot
] = *reloc_addr
;
372 addend
= saved_addends
[save_slot
++];
374 addend
= *reloc_addr
;
377 sym_index
= R_SYM(rel
[1]);
379 sym
= syms
+ sym_index
;
380 name
= strings
+ sym
->st_name
;
381 ctx
= type
==REL_COPY
? head
->syms_next
: head
;
382 def
= (sym
->st_info
>>4) == STB_LOCAL
383 ? (struct symdef
){ .dso
= dso
, .sym
= sym
}
384 : find_sym(ctx
, name
, type
==REL_PLT
);
385 if (!def
.sym
&& (sym
->st_shndx
!= SHN_UNDEF
386 || sym
->st_info
>>4 != STB_WEAK
)) {
387 if (dso
->lazy
&& (type
==REL_PLT
|| type
==REL_GOT
)) {
388 dso
->lazy
[3*dso
->lazy_cnt
+0] = rel
[0];
389 dso
->lazy
[3*dso
->lazy_cnt
+1] = rel
[1];
390 dso
->lazy
[3*dso
->lazy_cnt
+2] = addend
;
394 error("Error relocating %s: %s: symbol not found",
396 if (runtime
) longjmp(*rtld_fail
, 1);
405 sym_val
= def
.sym
? (size_t)laddr(def
.dso
, def
.sym
->st_value
) : 0;
406 tls_val
= def
.sym
? def
.sym
->st_value
: 0;
408 if ((type
== REL_TPOFF
|| type
== REL_TPOFF_NEG
)
409 && def
.dso
->tls_id
> static_tls_cnt
) {
410 error("Error relocating %s: %s: initial-exec TLS "
411 "resolves to dynamic definition in %s",
412 dso
->name
, name
, def
.dso
->name
);
413 longjmp(*rtld_fail
, 1);
418 addend
-= (size_t)reloc_addr
;
422 *reloc_addr
= sym_val
+ addend
;
425 memcpy(reloc_addr
, &(size_t){sym_val
+ addend
}, sizeof(size_t));
428 *reloc_addr
= (size_t)base
+ addend
;
431 if (sym
) *reloc_addr
= sym_val
+ addend
;
432 else *reloc_addr
= (size_t)base
+ addend
;
435 memcpy(reloc_addr
, (void *)sym_val
, sym
->st_size
);
438 *(uint32_t *)reloc_addr
= sym_val
+ addend
439 - (size_t)reloc_addr
;
442 *reloc_addr
= def
.sym
? (size_t)(def
.dso
->funcdescs
443 + (def
.sym
- def
.dso
->syms
)) : 0;
445 case REL_FUNCDESC_VAL
:
446 if ((sym
->st_info
&0xf) == STT_SECTION
) *reloc_addr
+= sym_val
;
447 else *reloc_addr
= sym_val
;
448 reloc_addr
[1] = def
.sym
? (size_t)def
.dso
->got
: 0;
451 *reloc_addr
= def
.dso
->tls_id
;
454 *reloc_addr
= tls_val
+ addend
- DTP_OFFSET
;
458 *reloc_addr
= tls_val
+ def
.dso
->tls
.offset
+ TPOFF_K
+ addend
;
462 *reloc_addr
= tls_val
- def
.dso
->tls
.offset
+ addend
;
465 *reloc_addr
= def
.dso
->tls
.offset
- tls_val
+ addend
;
469 if (stride
<3) addend
= reloc_addr
[1];
470 if (def
.dso
->tls_id
> static_tls_cnt
) {
471 struct td_index
*new = malloc(sizeof *new);
474 "Error relocating %s: cannot allocate TLSDESC for %s",
475 dso
->name
, sym
? name
: "(local)" );
476 longjmp(*rtld_fail
, 1);
478 new->next
= dso
->td_index
;
480 new->args
[0] = def
.dso
->tls_id
;
481 new->args
[1] = tls_val
+ addend
- DTP_OFFSET
;
482 reloc_addr
[0] = (size_t)__tlsdesc_dynamic
;
483 reloc_addr
[1] = (size_t)new;
485 reloc_addr
[0] = (size_t)__tlsdesc_static
;
487 reloc_addr
[1] = tls_val
+ def
.dso
->tls
.offset
490 reloc_addr
[1] = tls_val
- def
.dso
->tls
.offset
494 #ifdef TLSDESC_BACKWARDS
495 /* Some archs (32-bit ARM at least) invert the order of
496 * the descriptor members. Fix them up here. */
497 size_t tmp
= reloc_addr
[0];
498 reloc_addr
[0] = reloc_addr
[1];
503 error("Error relocating %s: unsupported relocation type %d",
505 if (runtime
) longjmp(*rtld_fail
, 1);
511 static void redo_lazy_relocs()
513 struct dso
*p
= lazy_head
, *next
;
517 size_t size
= p
->lazy_cnt
*3*sizeof(size_t);
519 do_relocs(p
, p
->lazy
, size
, 3);
521 p
->lazy_next
= lazy_head
;
531 /* A huge hack: to make up for the wastefulness of shared libraries
532 * needing at least a page of dirty memory even if they have no global
533 * data, we reclaim the gaps at the beginning and end of writable maps
534 * and "donate" them to the heap. */
536 static void reclaim(struct dso
*dso
, size_t start
, size_t end
)
538 if (start
>= dso
->relro_start
&& start
< dso
->relro_end
) start
= dso
->relro_end
;
539 if (end
>= dso
->relro_start
&& end
< dso
->relro_end
) end
= dso
->relro_start
;
540 if (start
>= end
) return;
541 char *base
= laddr_pg(dso
, start
);
542 __malloc_donate(base
, base
+(end
-start
));
545 static void reclaim_gaps(struct dso
*dso
)
547 Phdr
*ph
= dso
->phdr
;
548 size_t phcnt
= dso
->phnum
;
550 for (; phcnt
--; ph
=(void *)((char *)ph
+dso
->phentsize
)) {
551 if (ph
->p_type
!=PT_LOAD
) continue;
552 if ((ph
->p_flags
&(PF_R
|PF_W
))!=(PF_R
|PF_W
)) continue;
553 reclaim(dso
, ph
->p_vaddr
& -PAGE_SIZE
, ph
->p_vaddr
);
554 reclaim(dso
, ph
->p_vaddr
+ph
->p_memsz
,
555 ph
->p_vaddr
+ph
->p_memsz
+PAGE_SIZE
-1 & -PAGE_SIZE
);
559 static void *mmap_fixed(void *p
, size_t n
, int prot
, int flags
, int fd
, off_t off
)
561 static int no_map_fixed
;
564 q
= mmap(p
, n
, prot
, flags
|MAP_FIXED
, fd
, off
);
565 if (!DL_NOMMU_SUPPORT
|| q
!= MAP_FAILED
|| errno
!= EINVAL
)
569 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
570 if (flags
& MAP_ANONYMOUS
) {
575 if (lseek(fd
, off
, SEEK_SET
) < 0) return MAP_FAILED
;
576 for (q
=p
; n
; q
+=r
, off
+=r
, n
-=r
) {
578 if (r
< 0 && errno
!= EINTR
) return MAP_FAILED
;
587 static void unmap_library(struct dso
*dso
)
591 for (i
=0; i
<dso
->loadmap
->nsegs
; i
++) {
592 if (!dso
->loadmap
->segs
[i
].p_memsz
)
594 munmap((void *)dso
->loadmap
->segs
[i
].addr
,
595 dso
->loadmap
->segs
[i
].p_memsz
);
598 } else if (dso
->map
&& dso
->map_len
) {
599 munmap(dso
->map
, dso
->map_len
);
603 static void *map_library(int fd
, struct dso
*dso
)
605 Ehdr buf
[(896+sizeof(Ehdr
))/sizeof(Ehdr
)];
606 void *allocated_buf
=0;
608 size_t addr_min
=SIZE_MAX
, addr_max
=0, map_len
;
609 size_t this_min
, this_max
;
615 unsigned char *map
=MAP_FAILED
, *base
;
620 ssize_t l
= read(fd
, buf
, sizeof buf
);
623 if (l
<sizeof *eh
|| (eh
->e_type
!= ET_DYN
&& eh
->e_type
!= ET_EXEC
))
625 phsize
= eh
->e_phentsize
* eh
->e_phnum
;
626 if (phsize
> sizeof buf
- sizeof *eh
) {
627 allocated_buf
= malloc(phsize
);
628 if (!allocated_buf
) return 0;
629 l
= pread(fd
, allocated_buf
, phsize
, eh
->e_phoff
);
630 if (l
< 0) goto error
;
631 if (l
!= phsize
) goto noexec
;
632 ph
= ph0
= allocated_buf
;
633 } else if (eh
->e_phoff
+ phsize
> l
) {
634 l
= pread(fd
, buf
+1, phsize
, eh
->e_phoff
);
635 if (l
< 0) goto error
;
636 if (l
!= phsize
) goto noexec
;
637 ph
= ph0
= (void *)(buf
+ 1);
639 ph
= ph0
= (void *)((char *)buf
+ eh
->e_phoff
);
641 for (i
=eh
->e_phnum
; i
; i
--, ph
=(void *)((char *)ph
+eh
->e_phentsize
)) {
642 if (ph
->p_type
== PT_DYNAMIC
) {
644 } else if (ph
->p_type
== PT_TLS
) {
645 tls_image
= ph
->p_vaddr
;
646 dso
->tls
.align
= ph
->p_align
;
647 dso
->tls
.len
= ph
->p_filesz
;
648 dso
->tls
.size
= ph
->p_memsz
;
649 } else if (ph
->p_type
== PT_GNU_RELRO
) {
650 dso
->relro_start
= ph
->p_vaddr
& -PAGE_SIZE
;
651 dso
->relro_end
= (ph
->p_vaddr
+ ph
->p_memsz
) & -PAGE_SIZE
;
652 } else if (ph
->p_type
== PT_GNU_STACK
) {
653 if (!runtime
&& ph
->p_memsz
> __default_stacksize
) {
654 __default_stacksize
=
655 ph
->p_memsz
< DEFAULT_STACK_MAX
?
656 ph
->p_memsz
: DEFAULT_STACK_MAX
;
659 if (ph
->p_type
!= PT_LOAD
) continue;
661 if (ph
->p_vaddr
< addr_min
) {
662 addr_min
= ph
->p_vaddr
;
663 off_start
= ph
->p_offset
;
664 prot
= (((ph
->p_flags
&PF_R
) ? PROT_READ
: 0) |
665 ((ph
->p_flags
&PF_W
) ? PROT_WRITE
: 0) |
666 ((ph
->p_flags
&PF_X
) ? PROT_EXEC
: 0));
668 if (ph
->p_vaddr
+ph
->p_memsz
> addr_max
) {
669 addr_max
= ph
->p_vaddr
+ph
->p_memsz
;
672 if (!dyn
) goto noexec
;
673 if (DL_FDPIC
&& !(eh
->e_flags
& FDPIC_CONSTDISP_FLAG
)) {
674 dso
->loadmap
= calloc(1, sizeof *dso
->loadmap
675 + nsegs
* sizeof *dso
->loadmap
->segs
);
676 if (!dso
->loadmap
) goto error
;
677 dso
->loadmap
->nsegs
= nsegs
;
678 for (ph
=ph0
, i
=0; i
<nsegs
; ph
=(void *)((char *)ph
+eh
->e_phentsize
)) {
679 if (ph
->p_type
!= PT_LOAD
) continue;
680 prot
= (((ph
->p_flags
&PF_R
) ? PROT_READ
: 0) |
681 ((ph
->p_flags
&PF_W
) ? PROT_WRITE
: 0) |
682 ((ph
->p_flags
&PF_X
) ? PROT_EXEC
: 0));
683 map
= mmap(0, ph
->p_memsz
+ (ph
->p_vaddr
& PAGE_SIZE
-1),
685 fd
, ph
->p_offset
& -PAGE_SIZE
);
686 if (map
== MAP_FAILED
) {
690 dso
->loadmap
->segs
[i
].addr
= (size_t)map
+
691 (ph
->p_vaddr
& PAGE_SIZE
-1);
692 dso
->loadmap
->segs
[i
].p_vaddr
= ph
->p_vaddr
;
693 dso
->loadmap
->segs
[i
].p_memsz
= ph
->p_memsz
;
695 if (prot
& PROT_WRITE
) {
696 size_t brk
= (ph
->p_vaddr
& PAGE_SIZE
-1)
698 size_t pgbrk
= brk
+ PAGE_SIZE
-1 & -PAGE_SIZE
;
699 size_t pgend
= brk
+ ph
->p_memsz
- ph
->p_filesz
700 + PAGE_SIZE
-1 & -PAGE_SIZE
;
701 if (pgend
> pgbrk
&& mmap_fixed(map
+pgbrk
,
703 MAP_PRIVATE
|MAP_FIXED
|MAP_ANONYMOUS
,
704 -1, off_start
) == MAP_FAILED
)
706 memset(map
+ brk
, 0, pgbrk
-brk
);
709 map
= (void *)dso
->loadmap
->segs
[0].addr
;
713 addr_max
+= PAGE_SIZE
-1;
714 addr_max
&= -PAGE_SIZE
;
715 addr_min
&= -PAGE_SIZE
;
716 off_start
&= -PAGE_SIZE
;
717 map_len
= addr_max
- addr_min
+ off_start
;
718 /* The first time, we map too much, possibly even more than
719 * the length of the file. This is okay because we will not
720 * use the invalid part; we just need to reserve the right
721 * amount of virtual address space to map over later. */
722 map
= DL_NOMMU_SUPPORT
723 ? mmap((void *)addr_min
, map_len
, PROT_READ
|PROT_WRITE
|PROT_EXEC
,
724 MAP_PRIVATE
|MAP_ANONYMOUS
, -1, 0)
725 : mmap((void *)addr_min
, map_len
, prot
,
726 MAP_PRIVATE
, fd
, off_start
);
727 if (map
==MAP_FAILED
) goto error
;
729 dso
->map_len
= map_len
;
730 /* If the loaded file is not relocatable and the requested address is
731 * not available, then the load operation must fail. */
732 if (eh
->e_type
!= ET_DYN
&& addr_min
&& map
!=(void *)addr_min
) {
736 base
= map
- addr_min
;
739 for (ph
=ph0
, i
=eh
->e_phnum
; i
; i
--, ph
=(void *)((char *)ph
+eh
->e_phentsize
)) {
740 if (ph
->p_type
!= PT_LOAD
) continue;
741 /* Check if the programs headers are in this load segment, and
742 * if so, record the address for use by dl_iterate_phdr. */
743 if (!dso
->phdr
&& eh
->e_phoff
>= ph
->p_offset
744 && eh
->e_phoff
+phsize
<= ph
->p_offset
+ph
->p_filesz
) {
745 dso
->phdr
= (void *)(base
+ ph
->p_vaddr
746 + (eh
->e_phoff
-ph
->p_offset
));
747 dso
->phnum
= eh
->e_phnum
;
748 dso
->phentsize
= eh
->e_phentsize
;
750 this_min
= ph
->p_vaddr
& -PAGE_SIZE
;
751 this_max
= ph
->p_vaddr
+ph
->p_memsz
+PAGE_SIZE
-1 & -PAGE_SIZE
;
752 off_start
= ph
->p_offset
& -PAGE_SIZE
;
753 prot
= (((ph
->p_flags
&PF_R
) ? PROT_READ
: 0) |
754 ((ph
->p_flags
&PF_W
) ? PROT_WRITE
: 0) |
755 ((ph
->p_flags
&PF_X
) ? PROT_EXEC
: 0));
756 /* Reuse the existing mapping for the lowest-address LOAD */
757 if ((ph
->p_vaddr
& -PAGE_SIZE
) != addr_min
|| DL_NOMMU_SUPPORT
)
758 if (mmap_fixed(base
+this_min
, this_max
-this_min
, prot
, MAP_PRIVATE
|MAP_FIXED
, fd
, off_start
) == MAP_FAILED
)
760 if (ph
->p_memsz
> ph
->p_filesz
&& (ph
->p_flags
&PF_W
)) {
761 size_t brk
= (size_t)base
+ph
->p_vaddr
+ph
->p_filesz
;
762 size_t pgbrk
= brk
+PAGE_SIZE
-1 & -PAGE_SIZE
;
763 memset((void *)brk
, 0, pgbrk
-brk
& PAGE_SIZE
-1);
764 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
)
768 for (i
=0; ((size_t *)(base
+dyn
))[i
]; i
+=2)
769 if (((size_t *)(base
+dyn
))[i
]==DT_TEXTREL
) {
770 if (mprotect(map
, map_len
, PROT_READ
|PROT_WRITE
|PROT_EXEC
)
777 dso
->dynv
= laddr(dso
, dyn
);
778 if (dso
->tls
.size
) dso
->tls
.image
= laddr(dso
, tls_image
);
784 if (map
!=MAP_FAILED
) unmap_library(dso
);
789 static int path_open(const char *name
, const char *s
, char *buf
, size_t buf_size
)
794 s
+= strspn(s
, ":\n");
795 l
= strcspn(s
, ":\n");
796 if (l
-1 >= INT_MAX
) return -1;
797 if (snprintf(buf
, buf_size
, "%.*s/%s", (int)l
, s
, name
) < buf_size
) {
798 if ((fd
= open(buf
, O_RDONLY
|O_CLOEXEC
))>=0) return fd
;
806 /* Any negative value but -1 will inhibit
807 * futher path search. */
815 static int fixup_rpath(struct dso
*p
, char *buf
, size_t buf_size
)
818 const char *s
, *t
, *origin
;
820 if (p
->rpath
|| !p
->rpath_orig
) return 0;
821 if (!strchr(p
->rpath_orig
, '$')) {
822 p
->rpath
= p
->rpath_orig
;
827 while ((t
=strchr(s
, '$'))) {
828 if (strncmp(t
, "$ORIGIN", 7) && strncmp(t
, "${ORIGIN}", 9))
833 if (n
> SSIZE_MAX
/PATH_MAX
) return 0;
835 if (p
->kernel_mapped
) {
836 /* $ORIGIN searches cannot be performed for the main program
837 * when it is suid/sgid/AT_SECURE. This is because the
838 * pathname is under the control of the caller of execve.
839 * For libraries, however, $ORIGIN can be processed safely
840 * since the library's pathname came from a trusted source
841 * (either system paths or a call to dlopen). */
844 l
= readlink("/proc/self/exe", buf
, buf_size
);
845 if (l
== -1) switch (errno
) {
860 t
= strrchr(origin
, '/');
864 /* Normally p->name will always be an absolute or relative
865 * pathname containing at least one '/' character, but in the
866 * case where ldso was invoked as a command to execute a
867 * program in the working directory, app.name may not. Fix. */
871 /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
872 if (libc
.secure
&& *origin
!= '/')
874 p
->rpath
= malloc(strlen(p
->rpath_orig
) + n
*l
+ 1);
875 if (!p
->rpath
) return -1;
879 while ((t
=strchr(s
, '$'))) {
882 memcpy(d
, origin
, l
);
884 /* It was determined previously that the '$' is followed
885 * either by "ORIGIN" or "{ORIGIN}". */
886 s
= t
+ 7 + 2*(t
[1]=='{');
892 static void decode_dyn(struct dso
*p
)
895 decode_vec(p
->dynv
, dyn
, DYN_CNT
);
896 p
->syms
= laddr(p
, dyn
[DT_SYMTAB
]);
897 p
->strings
= laddr(p
, dyn
[DT_STRTAB
]);
898 if (dyn
[0]&(1<<DT_HASH
))
899 p
->hashtab
= laddr(p
, dyn
[DT_HASH
]);
900 if (dyn
[0]&(1<<DT_RPATH
))
901 p
->rpath_orig
= p
->strings
+ dyn
[DT_RPATH
];
902 if (dyn
[0]&(1<<DT_RUNPATH
))
903 p
->rpath_orig
= p
->strings
+ dyn
[DT_RUNPATH
];
904 if (dyn
[0]&(1<<DT_PLTGOT
))
905 p
->got
= laddr(p
, dyn
[DT_PLTGOT
]);
906 if (search_vec(p
->dynv
, dyn
, DT_GNU_HASH
))
907 p
->ghashtab
= laddr(p
, *dyn
);
908 if (search_vec(p
->dynv
, dyn
, DT_VERSYM
))
909 p
->versym
= laddr(p
, *dyn
);
912 static size_t count_syms(struct dso
*p
)
914 if (p
->hashtab
) return p
->hashtab
[1];
917 uint32_t *buckets
= p
->ghashtab
+ 4 + (p
->ghashtab
[2]*sizeof(size_t)/4);
919 for (i
= nsym
= 0; i
< p
->ghashtab
[0]; i
++) {
920 if (buckets
[i
] > nsym
)
924 hashval
= buckets
+ p
->ghashtab
[0] + (nsym
- p
->ghashtab
[1]);
926 while (!(*hashval
++ & 1));
931 static void *dl_mmap(size_t n
)
934 int prot
= PROT_READ
|PROT_WRITE
, flags
= MAP_ANONYMOUS
|MAP_PRIVATE
;
936 p
= (void *)__syscall(SYS_mmap2
, 0, n
, prot
, flags
, -1, 0);
938 p
= (void *)__syscall(SYS_mmap
, 0, n
, prot
, flags
, -1, 0);
940 return (unsigned long)p
> -4096UL ? 0 : p
;
943 static void makefuncdescs(struct dso
*p
)
945 static int self_done
;
946 size_t nsym
= count_syms(p
);
947 size_t i
, size
= nsym
* sizeof(*p
->funcdescs
);
950 p
->funcdescs
= dl_mmap(size
);
953 p
->funcdescs
= malloc(size
);
956 if (!runtime
) a_crash();
957 error("Error allocating function descriptors for %s", p
->name
);
958 longjmp(*rtld_fail
, 1);
960 for (i
=0; i
<nsym
; i
++) {
961 if ((p
->syms
[i
].st_info
&0xf)==STT_FUNC
&& p
->syms
[i
].st_shndx
) {
962 p
->funcdescs
[i
].addr
= laddr(p
, p
->syms
[i
].st_value
);
963 p
->funcdescs
[i
].got
= p
->got
;
965 p
->funcdescs
[i
].addr
= 0;
966 p
->funcdescs
[i
].got
= 0;
971 static struct dso
*load_library(const char *name
, struct dso
*needed_by
)
973 char buf
[2*NAME_MAX
+2];
974 const char *pathname
;
976 struct dso
*p
, temp_dso
= {0};
988 /* Catch and block attempts to reload the implementation itself */
989 if (name
[0]=='l' && name
[1]=='i' && name
[2]=='b') {
990 static const char reserved
[] =
991 "c.pthread.rt.m.dl.util.xnet.";
992 const char *rp
, *next
;
993 for (rp
=reserved
; *rp
; rp
=next
) {
994 next
= strchr(rp
, '.') + 1;
995 if (strncmp(name
+3, rp
, next
-rp
) == 0)
1000 /* Track which names have been resolved
1001 * and only report each one once. */
1002 static unsigned reported
;
1003 unsigned mask
= 1U<<(rp
-reserved
);
1004 if (!(reported
& mask
)) {
1006 dprintf(1, "\t%s => %s (%p)\n",
1014 if (!strcmp(name
, ldso
.name
)) is_self
= 1;
1023 if (strchr(name
, '/')) {
1025 fd
= open(name
, O_RDONLY
|O_CLOEXEC
);
1027 /* Search for the name to see if it's already loaded */
1028 for (p
=head
->next
; p
; p
=p
->next
) {
1029 if (p
->shortname
&& !strcmp(p
->shortname
, name
)) {
1033 if (strlen(name
) > NAME_MAX
) return 0;
1035 if (env_path
) fd
= path_open(name
, env_path
, buf
, sizeof buf
);
1036 for (p
=needed_by
; fd
== -1 && p
; p
=p
->needed_by
) {
1037 if (fixup_rpath(p
, buf
, sizeof buf
) < 0)
1038 fd
= -2; /* Inhibit further search. */
1040 fd
= path_open(name
, p
->rpath
, buf
, sizeof buf
);
1046 if (ldso
.name
[0]=='/') {
1048 for (s
=t
=z
=ldso
.name
; *s
; s
++)
1049 if (*s
=='/') z
=t
, t
=s
;
1050 prefix_len
= z
-ldso
.name
;
1051 if (prefix_len
< PATH_MAX
)
1058 char etc_ldso_path
[prefix_len
+ 1
1059 + sizeof "/etc/ld-musl-" LDSO_ARCH
".path"];
1060 snprintf(etc_ldso_path
, sizeof etc_ldso_path
,
1061 "%.*s/etc/ld-musl-" LDSO_ARCH
".path",
1062 (int)prefix_len
, prefix
);
1063 FILE *f
= fopen(etc_ldso_path
, "rbe");
1065 if (getdelim(&sys_path
, (size_t[1]){0}, 0, f
) <= 0) {
1070 } else if (errno
!= ENOENT
) {
1074 if (!sys_path
) sys_path
= "/lib:/usr/local/lib:/usr/lib";
1075 fd
= path_open(name
, sys_path
, buf
, sizeof buf
);
1079 if (fd
< 0) return 0;
1080 if (fstat(fd
, &st
) < 0) {
1084 for (p
=head
->next
; p
; p
=p
->next
) {
1085 if (p
->dev
== st
.st_dev
&& p
->ino
== st
.st_ino
) {
1086 /* If this library was previously loaded with a
1087 * pathname but a search found the same inode,
1088 * setup its shortname so it can be found by name. */
1089 if (!p
->shortname
&& pathname
!= name
)
1090 p
->shortname
= strrchr(p
->name
, '/')+1;
1095 map
= noload
? 0 : map_library(fd
, &temp_dso
);
1099 /* Avoid the danger of getting two versions of libc mapped into the
1100 * same process when an absolute pathname was used. The symbols
1101 * checked are chosen to catch both musl and glibc, and to avoid
1102 * false positives from interposition-hack libraries. */
1103 decode_dyn(&temp_dso
);
1104 if (find_sym(&temp_dso
, "__libc_start_main", 1).sym
&&
1105 find_sym(&temp_dso
, "stdin", 1).sym
) {
1106 unmap_library(&temp_dso
);
1107 return load_library("libc.so", needed_by
);
1109 /* Past this point, if we haven't reached runtime yet, ldso has
1110 * committed either to use the mapped library or to abort execution.
1111 * Unmapping is not possible, so we can safely reclaim gaps. */
1112 if (!runtime
) reclaim_gaps(&temp_dso
);
1114 /* Allocate storage for the new DSO. When there is TLS, this
1115 * storage must include a reservation for all pre-existing
1116 * threads to obtain copies of both the new TLS, and an
1117 * extended DTV capable of storing an additional slot for
1118 * the newly-loaded DSO. */
1119 alloc_size
= sizeof *p
+ strlen(pathname
) + 1;
1120 if (runtime
&& temp_dso
.tls
.image
) {
1121 size_t per_th
= temp_dso
.tls
.size
+ temp_dso
.tls
.align
1122 + sizeof(void *) * (tls_cnt
+3);
1123 n_th
= libc
.threads_minus_1
+ 1;
1124 if (n_th
> SSIZE_MAX
/ per_th
) alloc_size
= SIZE_MAX
;
1125 else alloc_size
+= n_th
* per_th
;
1127 p
= calloc(1, alloc_size
);
1129 unmap_library(&temp_dso
);
1132 memcpy(p
, &temp_dso
, sizeof temp_dso
);
1135 p
->needed_by
= needed_by
;
1137 p
->runtime_loaded
= runtime
;
1138 strcpy(p
->name
, pathname
);
1139 /* Add a shortname only if name arg was not an explicit pathname. */
1140 if (pathname
!= name
) p
->shortname
= strrchr(p
->name
, '/')+1;
1142 p
->tls_id
= ++tls_cnt
;
1143 tls_align
= MAXP2(tls_align
, p
->tls
.align
);
1145 p
->tls
.offset
= tls_offset
+ ( (p
->tls
.align
-1) &
1146 (-tls_offset
+ (uintptr_t)p
->tls
.image
) );
1147 tls_offset
= p
->tls
.offset
+ p
->tls
.size
;
1149 tls_offset
+= p
->tls
.size
+ p
->tls
.align
- 1;
1150 tls_offset
-= (tls_offset
+ (uintptr_t)p
->tls
.image
)
1152 p
->tls
.offset
= tls_offset
;
1154 p
->new_dtv
= (void *)(-sizeof(size_t) &
1155 (uintptr_t)(p
->name
+strlen(p
->name
)+sizeof(size_t)));
1156 p
->new_tls
= (void *)(p
->new_dtv
+ n_th
*(tls_cnt
+1));
1157 if (tls_tail
) tls_tail
->next
= &p
->tls
;
1158 else libc
.tls_head
= &p
->tls
;
1166 if (DL_FDPIC
) makefuncdescs(p
);
1168 if (ldd_mode
) dprintf(1, "\t%s => %s (%p)\n", name
, pathname
, p
->base
);
1173 static void load_direct_deps(struct dso
*p
)
1177 if (p
->deps
) return;
1178 /* For head, all preloads are direct pseudo-dependencies.
1179 * Count and include them now to avoid realloc later. */
1180 if (p
==head
) for (struct dso
*q
=p
->next
; q
; q
=q
->next
)
1182 for (i
=0; p
->dynv
[i
]; i
+=2)
1183 if (p
->dynv
[i
] == DT_NEEDED
) cnt
++;
1184 /* Use builtin buffer for apps with no external deps, to
1185 * preserve property of no runtime failure paths. */
1186 p
->deps
= (p
==head
&& cnt
<2) ? builtin_deps
:
1187 calloc(cnt
+1, sizeof *p
->deps
);
1189 error("Error loading dependencies for %s", p
->name
);
1190 if (runtime
) longjmp(*rtld_fail
, 1);
1193 if (p
==head
) for (struct dso
*q
=p
->next
; q
; q
=q
->next
)
1195 for (i
=0; p
->dynv
[i
]; i
+=2) {
1196 if (p
->dynv
[i
] != DT_NEEDED
) continue;
1197 struct dso
*dep
= load_library(p
->strings
+ p
->dynv
[i
+1], p
);
1199 error("Error loading shared library %s: %m (needed by %s)",
1200 p
->strings
+ p
->dynv
[i
+1], p
->name
);
1201 if (runtime
) longjmp(*rtld_fail
, 1);
1204 p
->deps
[cnt
++] = dep
;
1207 p
->ndeps_direct
= cnt
;
1210 static void load_deps(struct dso
*p
)
1212 if (p
->deps
) return;
1213 for (; p
; p
=p
->next
)
1214 load_direct_deps(p
);
1217 static void extend_bfs_deps(struct dso
*p
)
1219 size_t i
, j
, cnt
, ndeps_all
;
1222 /* Can't use realloc if the original p->deps was allocated at
1223 * program entry and malloc has been replaced, or if it's
1224 * the builtin non-allocated trivial main program deps array. */
1225 int no_realloc
= (__malloc_replaced
&& !p
->runtime_loaded
)
1226 || p
->deps
== builtin_deps
;
1228 if (p
->bfs_built
) return;
1229 ndeps_all
= p
->ndeps_direct
;
1231 /* Mark existing (direct) deps so they won't be duplicated. */
1232 for (i
=0; p
->deps
[i
]; i
++)
1233 p
->deps
[i
]->mark
= 1;
1235 /* For each dependency already in the list, copy its list of direct
1236 * dependencies to the list, excluding any items already in the
1237 * list. Note that the list this loop iterates over will grow during
1238 * the loop, but since duplicates are excluded, growth is bounded. */
1239 for (i
=0; p
->deps
[i
]; i
++) {
1240 struct dso
*dep
= p
->deps
[i
];
1241 for (j
=cnt
=0; j
<dep
->ndeps_direct
; j
++)
1242 if (!dep
->deps
[j
]->mark
) cnt
++;
1244 malloc(sizeof(*tmp
) * (ndeps_all
+cnt
+1)) :
1245 realloc(p
->deps
, sizeof(*tmp
) * (ndeps_all
+cnt
+1));
1247 error("Error recording dependencies for %s", p
->name
);
1248 if (runtime
) longjmp(*rtld_fail
, 1);
1252 memcpy(tmp
, p
->deps
, sizeof(*tmp
) * (ndeps_all
+1));
1256 for (j
=0; j
<dep
->ndeps_direct
; j
++) {
1257 if (dep
->deps
[j
]->mark
) continue;
1258 dep
->deps
[j
]->mark
= 1;
1259 p
->deps
[ndeps_all
++] = dep
->deps
[j
];
1261 p
->deps
[ndeps_all
] = 0;
1264 for (p
=head
; p
; p
=p
->next
)
1268 static void load_preload(char *s
)
1272 for (z
=s
; *z
; s
=z
) {
1273 for ( ; *s
&& (isspace(*s
) || *s
==':'); s
++);
1274 for (z
=s
; *z
&& !isspace(*z
) && *z
!=':'; z
++);
1282 static void add_syms(struct dso
*p
)
1284 if (!p
->syms_next
&& syms_tail
!= p
) {
1285 syms_tail
->syms_next
= p
;
1290 static void revert_syms(struct dso
*old_tail
)
1292 struct dso
*p
, *next
;
1293 /* Chop off the tail of the list of dsos that participate in
1294 * the global symbol table, reverting them to RTLD_LOCAL. */
1295 for (p
=old_tail
; p
; p
=next
) {
1296 next
= p
->syms_next
;
1299 syms_tail
= old_tail
;
1302 static void do_mips_relocs(struct dso
*p
, size_t *got
)
1304 size_t i
, j
, rel
[2];
1305 unsigned char *base
= p
->base
;
1306 i
=0; search_vec(p
->dynv
, &i
, DT_MIPS_LOCAL_GOTNO
);
1310 while (i
--) *got
++ += (size_t)base
;
1312 j
=0; search_vec(p
->dynv
, &j
, DT_MIPS_GOTSYM
);
1313 i
=0; search_vec(p
->dynv
, &i
, DT_MIPS_SYMTABNO
);
1314 Sym
*sym
= p
->syms
+ j
;
1315 rel
[0] = (unsigned char *)got
- base
;
1316 for (i
-=j
; i
; i
--, sym
++, rel
[0]+=sizeof(size_t)) {
1317 rel
[1] = R_INFO(sym
-p
->syms
, R_MIPS_JUMP_SLOT
);
1318 do_relocs(p
, rel
, sizeof rel
, 2);
1322 static void reloc_all(struct dso
*p
)
1324 size_t dyn
[DYN_CNT
];
1325 for (; p
; p
=p
->next
) {
1326 if (p
->relocated
) continue;
1327 decode_vec(p
->dynv
, dyn
, DYN_CNT
);
1328 if (NEED_MIPS_GOT_RELOCS
)
1329 do_mips_relocs(p
, laddr(p
, dyn
[DT_PLTGOT
]));
1330 do_relocs(p
, laddr(p
, dyn
[DT_JMPREL
]), dyn
[DT_PLTRELSZ
],
1331 2+(dyn
[DT_PLTREL
]==DT_RELA
));
1332 do_relocs(p
, laddr(p
, dyn
[DT_REL
]), dyn
[DT_RELSZ
], 2);
1333 do_relocs(p
, laddr(p
, dyn
[DT_RELA
]), dyn
[DT_RELASZ
], 3);
1335 if (head
!= &ldso
&& p
->relro_start
!= p
->relro_end
&&
1336 mprotect(laddr(p
, p
->relro_start
), p
->relro_end
-p
->relro_start
, PROT_READ
)
1337 && errno
!= ENOSYS
) {
1338 error("Error relocating %s: RELRO protection failed: %m",
1340 if (runtime
) longjmp(*rtld_fail
, 1);
1347 static void kernel_mapped_dso(struct dso
*p
)
1349 size_t min_addr
= -1, max_addr
= 0, cnt
;
1351 for (cnt
= p
->phnum
; cnt
--; ph
= (void *)((char *)ph
+ p
->phentsize
)) {
1352 if (ph
->p_type
== PT_DYNAMIC
) {
1353 p
->dynv
= laddr(p
, ph
->p_vaddr
);
1354 } else if (ph
->p_type
== PT_GNU_RELRO
) {
1355 p
->relro_start
= ph
->p_vaddr
& -PAGE_SIZE
;
1356 p
->relro_end
= (ph
->p_vaddr
+ ph
->p_memsz
) & -PAGE_SIZE
;
1357 } else if (ph
->p_type
== PT_GNU_STACK
) {
1358 if (!runtime
&& ph
->p_memsz
> __default_stacksize
) {
1359 __default_stacksize
=
1360 ph
->p_memsz
< DEFAULT_STACK_MAX
?
1361 ph
->p_memsz
: DEFAULT_STACK_MAX
;
1364 if (ph
->p_type
!= PT_LOAD
) continue;
1365 if (ph
->p_vaddr
< min_addr
)
1366 min_addr
= ph
->p_vaddr
;
1367 if (ph
->p_vaddr
+ph
->p_memsz
> max_addr
)
1368 max_addr
= ph
->p_vaddr
+ph
->p_memsz
;
1370 min_addr
&= -PAGE_SIZE
;
1371 max_addr
= (max_addr
+ PAGE_SIZE
-1) & -PAGE_SIZE
;
1372 p
->map
= p
->base
+ min_addr
;
1373 p
->map_len
= max_addr
- min_addr
;
1374 p
->kernel_mapped
= 1;
1377 void __libc_exit_fini()
1380 size_t dyn
[DYN_CNT
];
1381 int self
= __pthread_self()->tid
;
1383 /* Take both locks before setting shutting_down, so that
1384 * either lock is sufficient to read its value. The lock
1385 * order matches that in dlopen to avoid deadlock. */
1386 pthread_rwlock_wrlock(&lock
);
1387 pthread_mutex_lock(&init_fini_lock
);
1389 pthread_rwlock_unlock(&lock
);
1390 for (p
=fini_head
; p
; p
=p
->fini_next
) {
1391 while (p
->ctor_visitor
&& p
->ctor_visitor
!=self
)
1392 pthread_cond_wait(&ctor_cond
, &init_fini_lock
);
1393 if (!p
->constructed
) continue;
1394 decode_vec(p
->dynv
, dyn
, DYN_CNT
);
1395 if (dyn
[0] & (1<<DT_FINI_ARRAY
)) {
1396 size_t n
= dyn
[DT_FINI_ARRAYSZ
]/sizeof(size_t);
1397 size_t *fn
= (size_t *)laddr(p
, dyn
[DT_FINI_ARRAY
])+n
;
1398 while (n
--) ((void (*)(void))*--fn
)();
1400 #ifndef NO_LEGACY_INITFINI
1401 if ((dyn
[0] & (1<<DT_FINI
)) && dyn
[DT_FINI
])
1402 fpaddr(p
, dyn
[DT_FINI
])();
1407 static struct dso
**queue_ctors(struct dso
*dso
)
1409 size_t cnt
, qpos
, spos
, i
;
1410 struct dso
*p
, **queue
, **stack
;
1412 if (ldd_mode
) return 0;
1414 /* Bound on queue size is the total number of indirect deps.
1415 * If a bfs deps list was built, we can use it. Otherwise,
1416 * bound by the total number of DSOs, which is always safe and
1417 * is reasonable we use it (for main app at startup). */
1418 if (dso
->bfs_built
) {
1419 for (cnt
=0; dso
->deps
[cnt
]; cnt
++)
1420 dso
->deps
[cnt
]->mark
= 0;
1421 cnt
++; /* self, not included in deps */
1423 for (cnt
=0, p
=head
; p
; cnt
++, p
=p
->next
)
1426 cnt
++; /* termination slot */
1427 if (dso
==head
&& cnt
<= countof(builtin_ctor_queue
))
1428 queue
= builtin_ctor_queue
;
1430 queue
= calloc(cnt
, sizeof *queue
);
1433 error("Error allocating constructor queue: %m\n");
1434 if (runtime
) longjmp(*rtld_fail
, 1);
1438 /* Opposite ends of the allocated buffer serve as an output queue
1439 * and a working stack. Setup initial stack with just the argument
1440 * dso and initial queue empty... */
1444 stack
[--spos
] = dso
;
1448 /* Then perform pseudo-DFS sort, but ignoring circular deps. */
1451 while (p
->next_dep
< p
->ndeps_direct
) {
1452 if (p
->deps
[p
->next_dep
]->mark
) {
1456 p
= p
->deps
[p
->next_dep
];
1464 for (i
=0; i
<qpos
; i
++) queue
[i
]->mark
= 0;
1469 static void do_init_fini(struct dso
**queue
)
1472 size_t dyn
[DYN_CNT
], i
;
1473 int self
= __pthread_self()->tid
;
1475 pthread_mutex_lock(&init_fini_lock
);
1476 for (i
=0; (p
=queue
[i
]); i
++) {
1477 while ((p
->ctor_visitor
&& p
->ctor_visitor
!=self
) || shutting_down
)
1478 pthread_cond_wait(&ctor_cond
, &init_fini_lock
);
1479 if (p
->ctor_visitor
|| p
->constructed
)
1481 p
->ctor_visitor
= self
;
1483 decode_vec(p
->dynv
, dyn
, DYN_CNT
);
1484 if (dyn
[0] & ((1<<DT_FINI
) | (1<<DT_FINI_ARRAY
))) {
1485 p
->fini_next
= fini_head
;
1489 pthread_mutex_unlock(&init_fini_lock
);
1491 #ifndef NO_LEGACY_INITFINI
1492 if ((dyn
[0] & (1<<DT_INIT
)) && dyn
[DT_INIT
])
1493 fpaddr(p
, dyn
[DT_INIT
])();
1495 if (dyn
[0] & (1<<DT_INIT_ARRAY
)) {
1496 size_t n
= dyn
[DT_INIT_ARRAYSZ
]/sizeof(size_t);
1497 size_t *fn
= laddr(p
, dyn
[DT_INIT_ARRAY
]);
1498 while (n
--) ((void (*)(void))*fn
++)();
1501 pthread_mutex_lock(&init_fini_lock
);
1502 p
->ctor_visitor
= 0;
1504 pthread_cond_broadcast(&ctor_cond
);
1506 pthread_mutex_unlock(&init_fini_lock
);
1509 void __libc_start_init(void)
1511 do_init_fini(main_ctor_queue
);
1512 if (!__malloc_replaced
&& main_ctor_queue
!= builtin_ctor_queue
)
1513 free(main_ctor_queue
);
1514 main_ctor_queue
= 0;
1517 static void dl_debug_state(void)
1521 weak_alias(dl_debug_state
, _dl_debug_state
);
1523 void __init_tls(size_t *auxv
)
1527 static void update_tls_size()
1529 libc
.tls_cnt
= tls_cnt
;
1530 libc
.tls_align
= tls_align
;
1531 libc
.tls_size
= ALIGN(
1532 (1+tls_cnt
) * sizeof(void *) +
1534 sizeof(struct pthread
) +
1539 static void install_new_tls(void)
1542 pthread_t self
= __pthread_self(), td
;
1543 struct dso
*dtv_provider
= container_of(tls_tail
, struct dso
, tls
);
1544 uintptr_t (*newdtv
)[tls_cnt
+1] = (void *)dtv_provider
->new_dtv
;
1547 size_t old_cnt
= self
->dtv
[0];
1549 __block_app_sigs(&set
);
1551 /* Copy existing dtv contents from all existing threads. */
1552 for (i
=0, td
=self
; !i
|| td
!=self
; i
++, td
=td
->next
) {
1553 memcpy(newdtv
+i
, td
->dtv
,
1554 (old_cnt
+1)*sizeof(uintptr_t));
1555 newdtv
[i
][0] = tls_cnt
;
1557 /* Install new dtls into the enlarged, uninstalled dtv copies. */
1558 for (p
=head
; ; p
=p
->next
) {
1559 if (p
->tls_id
<= old_cnt
) continue;
1560 unsigned char *mem
= p
->new_tls
;
1561 for (j
=0; j
<i
; j
++) {
1562 unsigned char *new = mem
;
1563 new += ((uintptr_t)p
->tls
.image
- (uintptr_t)mem
)
1565 memcpy(new, p
->tls
.image
, p
->tls
.len
);
1566 newdtv
[j
][p
->tls_id
] =
1567 (uintptr_t)new + DTP_OFFSET
;
1568 mem
+= p
->tls
.size
+ p
->tls
.align
;
1570 if (p
->tls_id
== tls_cnt
) break;
1573 /* Broadcast barrier to ensure contents of new dtv is visible
1574 * if the new dtv pointer is. The __membarrier function has a
1575 * fallback emulation using signals for kernels that lack the
1576 * feature at the syscall level. */
1578 __membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED
, 0);
1580 /* Install new dtv for each thread. */
1581 for (j
=0, td
=self
; !j
|| td
!=self
; j
++, td
=td
->next
) {
1582 td
->dtv
= td
->dtv_copy
= newdtv
[j
];
1586 __restore_sigs(&set
);
1589 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1590 * following stage 2 and stage 3 functions via primitive symbolic lookup
1591 * since it does not have access to their addresses to begin with. */
1593 /* Stage 2 of the dynamic linker is called after relative relocations
1594 * have been processed. It can make function calls to static functions
1595 * and access string literals and static data, but cannot use extern
1596 * symbols. Its job is to perform symbolic relocations on the dynamic
1597 * linker itself, but some of the relocations performed may need to be
1598 * replaced later due to copy relocations in the main program. */
1600 hidden
void __dls2(unsigned char *base
, size_t *sp
)
1603 for (auxv
=sp
+1+*sp
+1; *auxv
; auxv
++);
1606 void *p1
= (void *)sp
[-2];
1607 void *p2
= (void *)sp
[-1];
1609 size_t aux
[AUX_CNT
];
1610 decode_vec(auxv
, aux
, AUX_CNT
);
1611 if (aux
[AT_BASE
]) ldso
.base
= (void *)aux
[AT_BASE
];
1612 else ldso
.base
= (void *)(aux
[AT_PHDR
] & -4096);
1614 app_loadmap
= p2
? p1
: 0;
1615 ldso
.loadmap
= p2
? p2
: p1
;
1616 ldso
.base
= laddr(&ldso
, 0);
1620 Ehdr
*ehdr
= (void *)ldso
.base
;
1621 ldso
.name
= ldso
.shortname
= "libc.so";
1622 ldso
.phnum
= ehdr
->e_phnum
;
1623 ldso
.phdr
= laddr(&ldso
, ehdr
->e_phoff
);
1624 ldso
.phentsize
= ehdr
->e_phentsize
;
1625 kernel_mapped_dso(&ldso
);
1628 if (DL_FDPIC
) makefuncdescs(&ldso
);
1630 /* Prepare storage for to save clobbered REL addends so they
1631 * can be reused in stage 3. There should be very few. If
1632 * something goes wrong and there are a huge number, abort
1633 * instead of risking stack overflow. */
1634 size_t dyn
[DYN_CNT
];
1635 decode_vec(ldso
.dynv
, dyn
, DYN_CNT
);
1636 size_t *rel
= laddr(&ldso
, dyn
[DT_REL
]);
1637 size_t rel_size
= dyn
[DT_RELSZ
];
1638 size_t symbolic_rel_cnt
= 0;
1639 apply_addends_to
= rel
;
1640 for (; rel_size
; rel
+=2, rel_size
-=2*sizeof(size_t))
1641 if (!IS_RELATIVE(rel
[1], ldso
.syms
)) symbolic_rel_cnt
++;
1642 if (symbolic_rel_cnt
>= ADDEND_LIMIT
) a_crash();
1643 size_t addends
[symbolic_rel_cnt
+1];
1644 saved_addends
= addends
;
1651 /* Call dynamic linker stage-2b, __dls2b, looking it up
1652 * symbolically as a barrier against moving the address
1653 * load across the above relocation processing. */
1654 struct symdef dls2b_def
= find_sym(&ldso
, "__dls2b", 0);
1655 if (DL_FDPIC
) ((stage3_func
)&ldso
.funcdescs
[dls2b_def
.sym
-ldso
.syms
])(sp
, auxv
);
1656 else ((stage3_func
)laddr(&ldso
, dls2b_def
.sym
->st_value
))(sp
, auxv
);
1659 /* Stage 2b sets up a valid thread pointer, which requires relocations
1660 * completed in stage 2, and on which stage 3 is permitted to depend.
1661 * This is done as a separate stage, with symbolic lookup as a barrier,
1662 * so that loads of the thread pointer and &errno can be pure/const and
1663 * thereby hoistable. */
1665 void __dls2b(size_t *sp
, size_t *auxv
)
1667 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1668 * use during dynamic linking. If possible it will also serve as the
1669 * thread pointer at runtime. */
1670 search_vec(auxv
, &__hwcap
, AT_HWCAP
);
1672 libc
.tls_size
= sizeof builtin_tls
;
1673 libc
.tls_align
= tls_align
;
1674 if (__init_tp(__copy_tls((void *)builtin_tls
)) < 0) {
1678 struct symdef dls3_def
= find_sym(&ldso
, "__dls3", 0);
1679 if (DL_FDPIC
) ((stage3_func
)&ldso
.funcdescs
[dls3_def
.sym
-ldso
.syms
])(sp
, auxv
);
1680 else ((stage3_func
)laddr(&ldso
, dls3_def
.sym
->st_value
))(sp
, auxv
);
1683 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1684 * fully functional. Its job is to load (if not already loaded) and
1685 * process dependencies and relocations for the main application and
1686 * transfer control to its entry point. */
1688 void __dls3(size_t *sp
, size_t *auxv
)
1690 static struct dso app
, vdso
;
1691 size_t aux
[AUX_CNT
];
1693 char *env_preload
=0;
1694 char *replace_argv0
=0;
1697 char **argv
= (void *)(sp
+1);
1698 char **argv_orig
= argv
;
1699 char **envp
= argv
+argc
+1;
1701 /* Find aux vector just past environ[] and use it to initialize
1702 * global data that may be needed before we can make syscalls. */
1704 decode_vec(auxv
, aux
, AUX_CNT
);
1705 search_vec(auxv
, &__sysinfo
, AT_SYSINFO
);
1706 __pthread_self()->sysinfo
= __sysinfo
;
1707 libc
.page_size
= aux
[AT_PAGESZ
];
1708 libc
.secure
= ((aux
[0]&0x7800)!=0x7800 || aux
[AT_UID
]!=aux
[AT_EUID
]
1709 || aux
[AT_GID
]!=aux
[AT_EGID
] || aux
[AT_SECURE
]);
1711 /* Only trust user/env if kernel says we're not suid/sgid */
1713 env_path
= getenv("LD_LIBRARY_PATH");
1714 env_preload
= getenv("LD_PRELOAD");
1717 /* If the main program was already loaded by the kernel,
1718 * AT_PHDR will point to some location other than the dynamic
1719 * linker's program headers. */
1720 if (aux
[AT_PHDR
] != (size_t)ldso
.phdr
) {
1721 size_t interp_off
= 0;
1722 size_t tls_image
= 0;
1723 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1724 Phdr
*phdr
= app
.phdr
= (void *)aux
[AT_PHDR
];
1725 app
.phnum
= aux
[AT_PHNUM
];
1726 app
.phentsize
= aux
[AT_PHENT
];
1727 for (i
=aux
[AT_PHNUM
]; i
; i
--, phdr
=(void *)((char *)phdr
+ aux
[AT_PHENT
])) {
1728 if (phdr
->p_type
== PT_PHDR
)
1729 app
.base
= (void *)(aux
[AT_PHDR
] - phdr
->p_vaddr
);
1730 else if (phdr
->p_type
== PT_INTERP
)
1731 interp_off
= (size_t)phdr
->p_vaddr
;
1732 else if (phdr
->p_type
== PT_TLS
) {
1733 tls_image
= phdr
->p_vaddr
;
1734 app
.tls
.len
= phdr
->p_filesz
;
1735 app
.tls
.size
= phdr
->p_memsz
;
1736 app
.tls
.align
= phdr
->p_align
;
1739 if (DL_FDPIC
) app
.loadmap
= app_loadmap
;
1740 if (app
.tls
.size
) app
.tls
.image
= laddr(&app
, tls_image
);
1741 if (interp_off
) ldso
.name
= laddr(&app
, interp_off
);
1742 if ((aux
[0] & (1UL<<AT_EXECFN
))
1743 && strncmp((char *)aux
[AT_EXECFN
], "/proc/", 6))
1744 app
.name
= (char *)aux
[AT_EXECFN
];
1747 kernel_mapped_dso(&app
);
1750 char *ldname
= argv
[0];
1751 size_t l
= strlen(ldname
);
1752 if (l
>= 3 && !strcmp(ldname
+l
-3, "ldd")) ldd_mode
= 1;
1754 while (argv
[0] && argv
[0][0]=='-' && argv
[0][1]=='-') {
1755 char *opt
= argv
[0]+2;
1756 *argv
++ = (void *)-1;
1759 } else if (!memcmp(opt
, "list", 5)) {
1761 } else if (!memcmp(opt
, "library-path", 12)) {
1762 if (opt
[12]=='=') env_path
= opt
+13;
1763 else if (opt
[12]) *argv
= 0;
1764 else if (*argv
) env_path
= *argv
++;
1765 } else if (!memcmp(opt
, "preload", 7)) {
1766 if (opt
[7]=='=') env_preload
= opt
+8;
1767 else if (opt
[7]) *argv
= 0;
1768 else if (*argv
) env_preload
= *argv
++;
1769 } else if (!memcmp(opt
, "argv0", 5)) {
1770 if (opt
[5]=='=') replace_argv0
= opt
+6;
1771 else if (opt
[5]) *argv
= 0;
1772 else if (*argv
) replace_argv0
= *argv
++;
1777 argv
[-1] = (void *)(argc
- (argv
-argv_orig
));
1779 dprintf(2, "musl libc (" LDSO_ARCH
")\n"
1781 "Dynamic Program Loader\n"
1782 "Usage: %s [options] [--] pathname%s\n",
1783 __libc_version
, ldname
,
1784 ldd_mode
? "" : " [args]");
1787 fd
= open(argv
[0], O_RDONLY
);
1789 dprintf(2, "%s: cannot load %s: %s\n", ldname
, argv
[0], strerror(errno
));
1792 Ehdr
*ehdr
= (void *)map_library(fd
, &app
);
1794 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname
, argv
[0]);
1800 aux
[AT_ENTRY
] = (size_t)laddr(&app
, ehdr
->e_entry
);
1801 /* Find the name that would have been used for the dynamic
1802 * linker had ldd not taken its place. */
1804 for (i
=0; i
<app
.phnum
; i
++) {
1805 if (app
.phdr
[i
].p_type
== PT_INTERP
)
1806 ldso
.name
= laddr(&app
, app
.phdr
[i
].p_vaddr
);
1808 dprintf(1, "\t%s (%p)\n", ldso
.name
, ldso
.base
);
1812 libc
.tls_head
= tls_tail
= &app
.tls
;
1813 app
.tls_id
= tls_cnt
= 1;
1815 app
.tls
.offset
= GAP_ABOVE_TP
;
1816 app
.tls
.offset
+= (-GAP_ABOVE_TP
+ (uintptr_t)app
.tls
.image
)
1817 & (app
.tls
.align
-1);
1818 tls_offset
= app
.tls
.offset
+ app
.tls
.size
;
1820 tls_offset
= app
.tls
.offset
= app
.tls
.size
1821 + ( -((uintptr_t)app
.tls
.image
+ app
.tls
.size
)
1822 & (app
.tls
.align
-1) );
1824 tls_align
= MAXP2(tls_align
, app
.tls
.align
);
1828 makefuncdescs(&app
);
1830 app
.loadmap
= (void *)&app_dummy_loadmap
;
1831 app
.loadmap
->nsegs
= 1;
1832 app
.loadmap
->segs
[0].addr
= (size_t)app
.map
;
1833 app
.loadmap
->segs
[0].p_vaddr
= (size_t)app
.map
1835 app
.loadmap
->segs
[0].p_memsz
= app
.map_len
;
1837 argv
[-3] = (void *)app
.loadmap
;
1840 /* Initial dso chain consists only of the app. */
1841 head
= tail
= syms_tail
= &app
;
1843 /* Donate unused parts of app and library mapping to malloc */
1845 reclaim_gaps(&ldso
);
1847 /* Load preload/needed libraries, add symbols to global namespace. */
1848 ldso
.deps
= (struct dso
**)no_deps
;
1849 if (env_preload
) load_preload(env_preload
);
1851 for (struct dso
*p
=head
; p
; p
=p
->next
)
1854 /* Attach to vdso, if provided by the kernel, last so that it does
1855 * not become part of the global namespace. */
1856 if (search_vec(auxv
, &vdso_base
, AT_SYSINFO_EHDR
) && vdso_base
) {
1857 Ehdr
*ehdr
= (void *)vdso_base
;
1858 Phdr
*phdr
= vdso
.phdr
= (void *)(vdso_base
+ ehdr
->e_phoff
);
1859 vdso
.phnum
= ehdr
->e_phnum
;
1860 vdso
.phentsize
= ehdr
->e_phentsize
;
1861 for (i
=ehdr
->e_phnum
; i
; i
--, phdr
=(void *)((char *)phdr
+ ehdr
->e_phentsize
)) {
1862 if (phdr
->p_type
== PT_DYNAMIC
)
1863 vdso
.dynv
= (void *)(vdso_base
+ phdr
->p_offset
);
1864 if (phdr
->p_type
== PT_LOAD
)
1865 vdso
.base
= (void *)(vdso_base
- phdr
->p_vaddr
+ phdr
->p_offset
);
1868 vdso
.shortname
= "linux-gate.so.1";
1870 vdso
.deps
= (struct dso
**)no_deps
;
1877 for (i
=0; app
.dynv
[i
]; i
+=2) {
1878 if (!DT_DEBUG_INDIRECT
&& app
.dynv
[i
]==DT_DEBUG
)
1879 app
.dynv
[i
+1] = (size_t)&debug
;
1880 if (DT_DEBUG_INDIRECT
&& app
.dynv
[i
]==DT_DEBUG_INDIRECT
) {
1881 size_t *ptr
= (size_t *) app
.dynv
[i
+1];
1882 *ptr
= (size_t)&debug
;
1886 /* This must be done before final relocations, since it calls
1887 * malloc, which may be provided by the application. Calling any
1888 * application code prior to the jump to its entry point is not
1889 * valid in our model and does not work with FDPIC, where there
1890 * are additional relocation-like fixups that only the entry point
1891 * code can see to perform. */
1892 main_ctor_queue
= queue_ctors(&app
);
1894 /* Initial TLS must also be allocated before final relocations
1895 * might result in calloc being a call to application code. */
1897 void *initial_tls
= builtin_tls
;
1898 if (libc
.tls_size
> sizeof builtin_tls
|| tls_align
> MIN_TLS_ALIGN
) {
1899 initial_tls
= calloc(libc
.tls_size
, 1);
1901 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1902 argv
[0], libc
.tls_size
);
1906 static_tls_cnt
= tls_cnt
;
1908 /* The main program must be relocated LAST since it may contain
1909 * copy relocations which depend on libraries' relocations. */
1910 reloc_all(app
.next
);
1913 /* Actual copying to new TLS needs to happen after relocations,
1914 * since the TLS images might have contained relocated addresses. */
1915 if (initial_tls
!= builtin_tls
) {
1916 if (__init_tp(__copy_tls(initial_tls
)) < 0) {
1920 size_t tmp_tls_size
= libc
.tls_size
;
1921 pthread_t self
= __pthread_self();
1922 /* Temporarily set the tls size to the full size of
1923 * builtin_tls so that __copy_tls will use the same layout
1924 * as it did for before. Then check, just to be safe. */
1925 libc
.tls_size
= sizeof builtin_tls
;
1926 if (__copy_tls((void*)builtin_tls
) != self
) a_crash();
1927 libc
.tls_size
= tmp_tls_size
;
1930 if (ldso_fail
) _exit(127);
1931 if (ldd_mode
) _exit(0);
1933 /* Determine if malloc was interposed by a replacement implementation
1934 * so that calloc and the memalign family can harden against the
1935 * possibility of incomplete replacement. */
1936 if (find_sym(head
, "malloc", 1).dso
!= &ldso
)
1937 __malloc_replaced
= 1;
1938 if (find_sym(head
, "aligned_alloc", 1).dso
!= &ldso
)
1939 __aligned_alloc_replaced
= 1;
1941 /* Switch to runtime mode: any further failures in the dynamic
1942 * linker are a reportable failure rather than a fatal startup
1947 debug
.bp
= dl_debug_state
;
1949 debug
.base
= ldso
.base
;
1953 if (replace_argv0
) argv
[0] = replace_argv0
;
1957 CRTJMP((void *)aux
[AT_ENTRY
], argv
-1);
1961 static void prepare_lazy(struct dso
*p
)
1963 size_t dyn
[DYN_CNT
], n
, flags1
=0;
1964 decode_vec(p
->dynv
, dyn
, DYN_CNT
);
1965 search_vec(p
->dynv
, &flags1
, DT_FLAGS_1
);
1966 if (dyn
[DT_BIND_NOW
] || (dyn
[DT_FLAGS
] & DF_BIND_NOW
) || (flags1
& DF_1_NOW
))
1968 n
= dyn
[DT_RELSZ
]/2 + dyn
[DT_RELASZ
]/3 + dyn
[DT_PLTRELSZ
]/2 + 1;
1969 if (NEED_MIPS_GOT_RELOCS
) {
1970 size_t j
=0; search_vec(p
->dynv
, &j
, DT_MIPS_GOTSYM
);
1971 size_t i
=0; search_vec(p
->dynv
, &i
, DT_MIPS_SYMTABNO
);
1974 p
->lazy
= calloc(n
, 3*sizeof(size_t));
1976 error("Error preparing lazy relocation for %s: %m", p
->name
);
1977 longjmp(*rtld_fail
, 1);
1979 p
->lazy_next
= lazy_head
;
1983 void *dlopen(const char *file
, int mode
)
1985 struct dso
*volatile p
, *orig_tail
, *orig_syms_tail
, *orig_lazy_head
, *next
;
1986 struct tls_module
*orig_tls_tail
;
1987 size_t orig_tls_cnt
, orig_tls_offset
, orig_tls_align
;
1991 struct dso
**volatile ctor_queue
= 0;
1993 if (!file
) return head
;
1995 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE
, &cs
);
1996 pthread_rwlock_wrlock(&lock
);
2000 if (shutting_down
) {
2001 error("Cannot dlopen while program is exiting.");
2004 orig_tls_tail
= tls_tail
;
2005 orig_tls_cnt
= tls_cnt
;
2006 orig_tls_offset
= tls_offset
;
2007 orig_tls_align
= tls_align
;
2008 orig_lazy_head
= lazy_head
;
2009 orig_syms_tail
= syms_tail
;
2011 noload
= mode
& RTLD_NOLOAD
;
2014 if (setjmp(*rtld_fail
)) {
2015 /* Clean up anything new that was (partially) loaded */
2016 revert_syms(orig_syms_tail
);
2017 for (p
=orig_tail
->next
; p
; p
=next
) {
2019 while (p
->td_index
) {
2020 void *tmp
= p
->td_index
->next
;
2025 if (p
->rpath
!= p
->rpath_orig
)
2033 if (!orig_tls_tail
) libc
.tls_head
= 0;
2034 tls_tail
= orig_tls_tail
;
2035 if (tls_tail
) tls_tail
->next
= 0;
2036 tls_cnt
= orig_tls_cnt
;
2037 tls_offset
= orig_tls_offset
;
2038 tls_align
= orig_tls_align
;
2039 lazy_head
= orig_lazy_head
;
2044 } else p
= load_library(file
, head
);
2048 "Library %s is not already loaded" :
2049 "Error loading shared library %s: %m",
2054 /* First load handling */
2057 pthread_mutex_lock(&init_fini_lock
);
2058 if (!p
->constructed
) ctor_queue
= queue_ctors(p
);
2059 pthread_mutex_unlock(&init_fini_lock
);
2060 if (!p
->relocated
&& (mode
& RTLD_LAZY
)) {
2062 for (i
=0; p
->deps
[i
]; i
++)
2063 if (!p
->deps
[i
]->relocated
)
2064 prepare_lazy(p
->deps
[i
]);
2066 if (!p
->relocated
|| (mode
& RTLD_GLOBAL
)) {
2067 /* Make new symbols global, at least temporarily, so we can do
2068 * relocations. If not RTLD_GLOBAL, this is reverted below. */
2070 for (i
=0; p
->deps
[i
]; i
++)
2071 add_syms(p
->deps
[i
]);
2073 if (!p
->relocated
) {
2077 /* If RTLD_GLOBAL was not specified, undo any new additions
2078 * to the global symbol table. This is a nop if the library was
2079 * previously loaded and already global. */
2080 if (!(mode
& RTLD_GLOBAL
))
2081 revert_syms(orig_syms_tail
);
2083 /* Processing of deferred lazy relocations must not happen until
2084 * the new libraries are committed; otherwise we could end up with
2085 * relocations resolved to symbol definitions that get removed. */
2089 if (tls_cnt
!= orig_tls_cnt
)
2096 pthread_rwlock_unlock(&lock
);
2098 do_init_fini(ctor_queue
);
2101 pthread_setcancelstate(cs
, 0);
2105 hidden
int __dl_invalid_handle(void *h
)
2108 for (p
=head
; p
; p
=p
->next
) if (h
==p
) return 0;
2109 error("Invalid library handle %p", (void *)h
);
2113 static void *addr2dso(size_t a
)
2117 if (DL_FDPIC
) for (p
=head
; p
; p
=p
->next
) {
2119 if (a
-(size_t)p
->funcdescs
< i
*sizeof(*p
->funcdescs
))
2122 for (p
=head
; p
; p
=p
->next
) {
2123 if (DL_FDPIC
&& p
->loadmap
) {
2124 for (i
=0; i
<p
->loadmap
->nsegs
; i
++) {
2125 if (a
-p
->loadmap
->segs
[i
].p_vaddr
2126 < p
->loadmap
->segs
[i
].p_memsz
)
2131 size_t phcnt
= p
->phnum
;
2132 size_t entsz
= p
->phentsize
;
2133 size_t base
= (size_t)p
->base
;
2134 for (; phcnt
--; ph
=(void *)((char *)ph
+entsz
)) {
2135 if (ph
->p_type
!= PT_LOAD
) continue;
2136 if (a
-base
-ph
->p_vaddr
< ph
->p_memsz
)
2139 if (a
-(size_t)p
->map
< p
->map_len
)
2146 static void *do_dlsym(struct dso
*p
, const char *s
, void *ra
)
2149 if (p
== head
|| p
== RTLD_DEFAULT
) {
2151 } else if (p
== RTLD_NEXT
) {
2152 p
= addr2dso((size_t)ra
);
2155 } else if (__dl_invalid_handle(p
)) {
2159 struct symdef def
= find_sym2(p
, s
, 0, use_deps
);
2161 error("Symbol not found: %s", s
);
2164 if ((def
.sym
->st_info
&0xf) == STT_TLS
)
2165 return __tls_get_addr((tls_mod_off_t
[]){def
.dso
->tls_id
, def
.sym
->st_value
-DTP_OFFSET
});
2166 if (DL_FDPIC
&& (def
.sym
->st_info
&0xf) == STT_FUNC
)
2167 return def
.dso
->funcdescs
+ (def
.sym
- def
.dso
->syms
);
2168 return laddr(def
.dso
, def
.sym
->st_value
);
2171 int dladdr(const void *addr_arg
, Dl_info
*info
)
2173 size_t addr
= (size_t)addr_arg
;
2179 size_t besterr
= -1;
2181 pthread_rwlock_rdlock(&lock
);
2183 pthread_rwlock_unlock(&lock
);
2188 strings
= p
->strings
;
2189 nsym
= count_syms(p
);
2192 size_t idx
= (addr
-(size_t)p
->funcdescs
)
2193 / sizeof(*p
->funcdescs
);
2194 if (idx
< nsym
&& (sym
[idx
].st_info
&0xf) == STT_FUNC
) {
2195 best
= (size_t)(p
->funcdescs
+ idx
);
2196 bestsym
= sym
+ idx
;
2201 if (!best
) for (; nsym
; nsym
--, sym
++) {
2203 && (1<<(sym
->st_info
&0xf) & OK_TYPES
)
2204 && (1<<(sym
->st_info
>>4) & OK_BINDS
)) {
2205 size_t symaddr
= (size_t)laddr(p
, sym
->st_value
);
2206 if (symaddr
> addr
|| symaddr
<= best
)
2210 besterr
= addr
- symaddr
;
2211 if (addr
== symaddr
)
2216 if (best
&& besterr
> bestsym
->st_size
-1) {
2221 info
->dli_fname
= p
->name
;
2222 info
->dli_fbase
= p
->map
;
2225 info
->dli_sname
= 0;
2226 info
->dli_saddr
= 0;
2230 if (DL_FDPIC
&& (bestsym
->st_info
&0xf) == STT_FUNC
)
2231 best
= (size_t)(p
->funcdescs
+ (bestsym
- p
->syms
));
2232 info
->dli_sname
= strings
+ bestsym
->st_name
;
2233 info
->dli_saddr
= (void *)best
;
2238 hidden
void *__dlsym(void *restrict p
, const char *restrict s
, void *restrict ra
)
2241 pthread_rwlock_rdlock(&lock
);
2242 res
= do_dlsym(p
, s
, ra
);
2243 pthread_rwlock_unlock(&lock
);
2247 hidden
void *__dlsym_redir_time64(void *restrict p
, const char *restrict s
, void *restrict ra
)
2250 const char *suffix
, *suffix2
= "";
2253 /* Map the symbol name to a time64 version of itself according to the
2254 * pattern used for naming the redirected time64 symbols. */
2255 size_t l
= strnlen(s
, sizeof redir
);
2256 if (l
<4 || l
==sizeof redir
) goto no_redir
;
2257 if (s
[l
-2]=='_' && s
[l
-1]=='r') {
2261 if (l
<4) goto no_redir
;
2262 if (!strcmp(s
+l
-4, "time")) suffix
= "64";
2263 else suffix
= "_time64";
2265 /* Use the presence of the remapped symbol name in libc to determine
2266 * whether it's one that requires time64 redirection; replace if so. */
2267 snprintf(redir
, sizeof redir
, "__%.*s%s%s", (int)l
, s
, suffix
, suffix2
);
2268 if (find_sym(&ldso
, redir
, 1).sym
) s
= redir
;
2271 return __dlsym(p
, s
, ra
);
2274 int dl_iterate_phdr(int(*callback
)(struct dl_phdr_info
*info
, size_t size
, void *data
), void *data
)
2276 struct dso
*current
;
2277 struct dl_phdr_info info
;
2279 for(current
= head
; current
;) {
2280 info
.dlpi_addr
= (uintptr_t)current
->base
;
2281 info
.dlpi_name
= current
->name
;
2282 info
.dlpi_phdr
= current
->phdr
;
2283 info
.dlpi_phnum
= current
->phnum
;
2284 info
.dlpi_adds
= gencnt
;
2286 info
.dlpi_tls_modid
= current
->tls_id
;
2287 info
.dlpi_tls_data
= current
->tls
.image
;
2289 ret
= (callback
)(&info
, sizeof (info
), data
);
2291 if (ret
!= 0) break;
2293 pthread_rwlock_rdlock(&lock
);
2294 current
= current
->next
;
2295 pthread_rwlock_unlock(&lock
);
2300 static void error(const char *fmt
, ...)
2305 vdprintf(2, fmt
, ap
);
2311 __dl_vseterr(fmt
, ap
);