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bionic/linker: allow resolving of symbols from library back to executable

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Signed-off-by: Iliyan Malchev <malchev@google.com>
This commit is contained in:
Iliyan Malchev 2009-09-29 11:43:20 -07:00
parent 9ea64da6c5
commit 4a9afcb101
1 changed files with 25 additions and 0 deletions
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25
linker/linker.c
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@ -51,6 +51,7 @@
#include "ba.h" #include "ba.h"
#define ALLOW_SYMBOLS_FROM_MAIN 1
#define SO_MAX 96 #define SO_MAX 96
/* Assume average path length of 64 and max 8 paths */ /* Assume average path length of 64 and max 8 paths */
@ -86,6 +87,9 @@ static soinfo sopool[SO_MAX];
static soinfo *freelist = NULL; static soinfo *freelist = NULL;
static soinfo *solist = &libdl_info; static soinfo *solist = &libdl_info;
static soinfo *sonext = &libdl_info; static soinfo *sonext = &libdl_info;
#if ALLOW_SYMBOLS_FROM_MAIN
static soinfo *somain; /* main process, always the one after libdl_info */
#endif
static inline int validate_soinfo(soinfo *si) static inline int validate_soinfo(soinfo *si)
{ {
@ -459,6 +463,19 @@ _do_lookup(soinfo *si, const char *name, unsigned *base)
} }
} }
#if ALLOW_SYMBOLS_FROM_MAIN
/* If we are resolving relocations while dlopen()ing a library, it's OK for
* the library to resolve a symbol that's defined in the executable itself,
* although this is rare and is generally a bad idea.
*/
if (somain) {
lsi = somain;
DEBUG("%5d %s: looking up %s in executable %s\n",
pid, si->name, name, lsi->name);
s = _do_lookup_in_so(lsi, name, &elf_hash);
}
#endif
done: done:
if(s != NULL) { if(s != NULL) {
TRACE_TYPE(LOOKUP, "%5d si %s sym %s s->st_value = 0x%08x, " TRACE_TYPE(LOOKUP, "%5d si %s sym %s s->st_value = 0x%08x, "
@ -1894,6 +1911,14 @@ unsigned __linker_init(unsigned **elfdata)
exit(-1); exit(-1);
} }
#if ALLOW_SYMBOLS_FROM_MAIN
/* Set somain after we've loaded all the libraries in order to prevent
* linking of symbols back to the main image, which is not set up at that
* point yet.
*/
somain = si;
#endif
#if TIMING #if TIMING
gettimeofday(&t1,NULL); gettimeofday(&t1,NULL);
PRINT("LINKER TIME: %s: %d microseconds\n", argv[0], (int) ( PRINT("LINKER TIME: %s: %d microseconds\n", argv[0], (int) (