Implement dlsym(RTLD_NEXT, symbol).
This commit is contained in:
parent
8889c700f3
commit
7e7344e2f4
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=27838
@ -27,7 +27,7 @@
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* $Id$
|
||||
* $Id: rtld.c,v 1.46 1997/02/22 15:46:48 peter Exp $
|
||||
*/
|
||||
|
||||
#include <sys/param.h>
|
||||
@ -204,9 +204,10 @@ static int __dlclose __P((void *));
|
||||
static void *__dlsym __P((void *, char *));
|
||||
static char *__dlerror __P((void));
|
||||
static void __dlexit __P((void));
|
||||
static void *__dlsym3 __P((void *, char *, void *));
|
||||
|
||||
static struct ld_entry ld_entry = {
|
||||
__dlopen, __dlclose, __dlsym, __dlerror, __dlexit
|
||||
__dlopen, __dlclose, __dlsym, __dlerror, __dlexit, __dlsym3
|
||||
};
|
||||
|
||||
void xprintf __P((char *, ...));
|
||||
@ -411,7 +412,7 @@ struct _dynamic *dp;
|
||||
(void)close(crtp->crt_ldfd);
|
||||
anon_close();
|
||||
|
||||
return LDSO_VERSION_HAS_DLEXIT;
|
||||
return LDSO_VERSION_HAS_DLSYM3;
|
||||
}
|
||||
|
||||
void
|
||||
@ -1896,15 +1897,63 @@ __dlclose(fd)
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* This form of dlsym is obsolete. Current versions of crt0 don't call
|
||||
* it. It can still be called by old executables that were linked with
|
||||
* old versions of crt0.
|
||||
*/
|
||||
static void *
|
||||
__dlsym(fd, sym)
|
||||
void *fd;
|
||||
char *sym;
|
||||
{
|
||||
struct so_map *smp = (struct so_map *)fd, *src_map = NULL;
|
||||
if (fd == RTLD_NEXT) {
|
||||
generror("RTLD_NEXT not supported by this version of"
|
||||
" /usr/lib/crt0.o");
|
||||
return NULL;
|
||||
}
|
||||
return __dlsym3(fd, sym, NULL);
|
||||
}
|
||||
|
||||
static void *
|
||||
__dlsym3(fd, sym, retaddr)
|
||||
void *fd;
|
||||
char *sym;
|
||||
void *retaddr;
|
||||
{
|
||||
struct so_map *smp;
|
||||
struct so_map *src_map;
|
||||
struct nzlist *np;
|
||||
long addr;
|
||||
|
||||
if (fd == RTLD_NEXT) {
|
||||
/* Find the shared object that contains the caller. */
|
||||
for (smp = link_map_head; smp != NULL; smp = smp->som_next) {
|
||||
void *textbase = smp->som_addr + LM_TXTADDR(smp);
|
||||
void *textlimit = LM_ETEXT(smp);
|
||||
|
||||
if (textbase <= retaddr && retaddr < textlimit)
|
||||
break;
|
||||
}
|
||||
if (smp == NULL) {
|
||||
generror("Cannot determine caller's shared object");
|
||||
return NULL;
|
||||
}
|
||||
smp = smp->som_next;
|
||||
if (smp != NULL && LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
|
||||
smp = smp->som_next;
|
||||
if (smp == NULL) {
|
||||
generror("No next shared object for RTLD_NEXT");
|
||||
return NULL;
|
||||
}
|
||||
do {
|
||||
src_map = smp;
|
||||
np = lookup(sym, &src_map, 1);
|
||||
} while (np == NULL && (smp = smp->som_next) != NULL);
|
||||
} else {
|
||||
smp = (struct so_map *)fd;
|
||||
src_map = NULL;
|
||||
|
||||
/*
|
||||
* Restrict search to passed map if dlopen()ed.
|
||||
*/
|
||||
@ -1912,10 +1961,13 @@ __dlsym(fd, sym)
|
||||
src_map = smp;
|
||||
|
||||
np = lookup(sym, &src_map, 1);
|
||||
if (np == NULL)
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (np == NULL) {
|
||||
generror("Undefined symbol");
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/* Fixup jmpslot so future calls transfer directly to target */
|
||||
addr = np->nz_value;
|
||||
if (src_map)
|
||||
addr += (long)src_map->som_addr;
|
||||
|
@ -27,7 +27,7 @@
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* $Id: link.h,v 1.12 1997/05/07 02:26:34 eivind Exp $
|
||||
* $Id: link.h,v 1.13 1997/05/07 20:00:00 eivind Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -167,6 +167,7 @@ struct so_debug {
|
||||
*/
|
||||
#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
|
||||
#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
|
||||
#define LDSO_VERSION_HAS_DLSYM3 2 /* includes 3-argument dlsym */
|
||||
|
||||
/*
|
||||
* Entry points into ld.so - user interface to the run-time linker.
|
||||
@ -179,6 +180,7 @@ struct ld_entry {
|
||||
void *(*dlsym) __P((void *, char *)); /* NONE */
|
||||
char *(*dlerror) __P((void)); /* NONE */
|
||||
void (*dlexit) __P((void)); /* HAS_DLEXIT */
|
||||
void *(*dlsym3) __P((void *, char *, void *)); /* HAS_DLSYM3 */
|
||||
};
|
||||
|
||||
/*
|
||||
|
@ -27,7 +27,7 @@
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* $Id$
|
||||
* $Id: crt0.c,v 1.29 1997/02/22 14:57:44 peter Exp $
|
||||
*/
|
||||
|
||||
#include <sys/param.h>
|
||||
@ -94,6 +94,8 @@ static char empty[1];
|
||||
char *__progname = empty;
|
||||
char **environ;
|
||||
|
||||
static int ldso_version;
|
||||
|
||||
extern unsigned char etext;
|
||||
extern unsigned char eprol asm ("eprol");
|
||||
extern start() asm("start");
|
||||
@ -194,7 +196,6 @@ __do_dynamic_link ()
|
||||
struct exec hdr;
|
||||
char *ldso;
|
||||
int (*entry)();
|
||||
int ret;
|
||||
|
||||
#ifdef DEBUG
|
||||
/* Provision for alternate ld.so - security risk! */
|
||||
@ -254,14 +255,14 @@ __do_dynamic_link ()
|
||||
crt.crt_ldentry = NULL;
|
||||
|
||||
entry = (int (*)())(crt.crt_ba + sizeof hdr);
|
||||
ret = (*entry)(CRT_VERSION_BSD_4, &crt);
|
||||
ldso_version = (*entry)(CRT_VERSION_BSD_4, &crt);
|
||||
ld_entry = crt.crt_ldentry;
|
||||
if (ret == -1 && ld_entry == NULL) {
|
||||
if (ldso_version == -1 && ld_entry == NULL) {
|
||||
/* if version 4 not recognised, try version 3 */
|
||||
ret = (*entry)(CRT_VERSION_BSD_3, &crt);
|
||||
ldso_version = (*entry)(CRT_VERSION_BSD_3, &crt);
|
||||
ld_entry = _DYNAMIC.d_entry;
|
||||
}
|
||||
if (ret == -1) {
|
||||
if (ldso_version == -1) {
|
||||
_PUTMSG("ld.so failed");
|
||||
if (ld_entry != NULL) {
|
||||
char *msg = (ld_entry->dlerror)();
|
||||
@ -277,7 +278,7 @@ __do_dynamic_link ()
|
||||
}
|
||||
|
||||
|
||||
if (ret >= LDSO_VERSION_HAS_DLEXIT)
|
||||
if (ldso_version >= LDSO_VERSION_HAS_DLEXIT)
|
||||
atexit(ld_entry->dlexit);
|
||||
|
||||
return;
|
||||
@ -316,6 +317,10 @@ char *name;
|
||||
if (ld_entry == NULL)
|
||||
return NULL;
|
||||
|
||||
if (ldso_version >= LDSO_VERSION_HAS_DLSYM3) {
|
||||
void *retaddr = *(&fd - 1); /* XXX - ABI/machine dependent */
|
||||
return (ld_entry->dlsym3)(fd, name, retaddr);
|
||||
} else
|
||||
return (ld_entry->dlsym)(fd, name);
|
||||
}
|
||||
|
||||
|
@ -43,6 +43,13 @@
|
||||
#define RTLD_LAZY 1 /* Bind function calls lazily */
|
||||
#define RTLD_NOW 2 /* Bind function calls immediately */
|
||||
|
||||
/*
|
||||
* Special handle argument for dlsym(). It causes the search for the
|
||||
* symbol to begin in the next shared object after the one containing
|
||||
* the caller.
|
||||
*/
|
||||
#define RTLD_NEXT ((void *) -1)
|
||||
|
||||
__BEGIN_DECLS
|
||||
void *dlopen __P((char *, int));
|
||||
void *dlsym __P((void *, char *));
|
||||
|
@ -152,6 +152,28 @@ returns a null pointer if the symbol cannot be found, and sets an error
|
||||
condition which may be queried with
|
||||
.Fn dlerror .
|
||||
.Pp
|
||||
If
|
||||
.Fn dlsym
|
||||
is called with the special
|
||||
.Fa handle
|
||||
.Dv RTLD_NEXT ,
|
||||
then the search for the symbol is limited to the shared objects
|
||||
which were loaded after the one issuing the call to
|
||||
.Fn dlsym .
|
||||
Thus, if the function is called from the main program, all
|
||||
the shared libraries are searched.
|
||||
If it is called from a shared library, all subsequent shared
|
||||
libraries are searched.
|
||||
.Dv RTLD_NEXT
|
||||
is useful for implementing wrappers around library functions.
|
||||
For example, a wrapper function
|
||||
.Fn getpid
|
||||
could access the
|
||||
.Dq real
|
||||
.Fn getpid
|
||||
with
|
||||
.Li dlsym(RTLD_NEXT, \&"_getpid\&") .
|
||||
.Pp
|
||||
.Fn dlerror
|
||||
returns a null-terminated character string describing the last error that
|
||||
occurred during a call to
|
||||
|
@ -27,7 +27,7 @@
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* $Id$
|
||||
* $Id: rtld.c,v 1.46 1997/02/22 15:46:48 peter Exp $
|
||||
*/
|
||||
|
||||
#include <sys/param.h>
|
||||
@ -204,9 +204,10 @@ static int __dlclose __P((void *));
|
||||
static void *__dlsym __P((void *, char *));
|
||||
static char *__dlerror __P((void));
|
||||
static void __dlexit __P((void));
|
||||
static void *__dlsym3 __P((void *, char *, void *));
|
||||
|
||||
static struct ld_entry ld_entry = {
|
||||
__dlopen, __dlclose, __dlsym, __dlerror, __dlexit
|
||||
__dlopen, __dlclose, __dlsym, __dlerror, __dlexit, __dlsym3
|
||||
};
|
||||
|
||||
void xprintf __P((char *, ...));
|
||||
@ -411,7 +412,7 @@ struct _dynamic *dp;
|
||||
(void)close(crtp->crt_ldfd);
|
||||
anon_close();
|
||||
|
||||
return LDSO_VERSION_HAS_DLEXIT;
|
||||
return LDSO_VERSION_HAS_DLSYM3;
|
||||
}
|
||||
|
||||
void
|
||||
@ -1896,15 +1897,63 @@ __dlclose(fd)
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* This form of dlsym is obsolete. Current versions of crt0 don't call
|
||||
* it. It can still be called by old executables that were linked with
|
||||
* old versions of crt0.
|
||||
*/
|
||||
static void *
|
||||
__dlsym(fd, sym)
|
||||
void *fd;
|
||||
char *sym;
|
||||
{
|
||||
struct so_map *smp = (struct so_map *)fd, *src_map = NULL;
|
||||
if (fd == RTLD_NEXT) {
|
||||
generror("RTLD_NEXT not supported by this version of"
|
||||
" /usr/lib/crt0.o");
|
||||
return NULL;
|
||||
}
|
||||
return __dlsym3(fd, sym, NULL);
|
||||
}
|
||||
|
||||
static void *
|
||||
__dlsym3(fd, sym, retaddr)
|
||||
void *fd;
|
||||
char *sym;
|
||||
void *retaddr;
|
||||
{
|
||||
struct so_map *smp;
|
||||
struct so_map *src_map;
|
||||
struct nzlist *np;
|
||||
long addr;
|
||||
|
||||
if (fd == RTLD_NEXT) {
|
||||
/* Find the shared object that contains the caller. */
|
||||
for (smp = link_map_head; smp != NULL; smp = smp->som_next) {
|
||||
void *textbase = smp->som_addr + LM_TXTADDR(smp);
|
||||
void *textlimit = LM_ETEXT(smp);
|
||||
|
||||
if (textbase <= retaddr && retaddr < textlimit)
|
||||
break;
|
||||
}
|
||||
if (smp == NULL) {
|
||||
generror("Cannot determine caller's shared object");
|
||||
return NULL;
|
||||
}
|
||||
smp = smp->som_next;
|
||||
if (smp != NULL && LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
|
||||
smp = smp->som_next;
|
||||
if (smp == NULL) {
|
||||
generror("No next shared object for RTLD_NEXT");
|
||||
return NULL;
|
||||
}
|
||||
do {
|
||||
src_map = smp;
|
||||
np = lookup(sym, &src_map, 1);
|
||||
} while (np == NULL && (smp = smp->som_next) != NULL);
|
||||
} else {
|
||||
smp = (struct so_map *)fd;
|
||||
src_map = NULL;
|
||||
|
||||
/*
|
||||
* Restrict search to passed map if dlopen()ed.
|
||||
*/
|
||||
@ -1912,10 +1961,13 @@ __dlsym(fd, sym)
|
||||
src_map = smp;
|
||||
|
||||
np = lookup(sym, &src_map, 1);
|
||||
if (np == NULL)
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (np == NULL) {
|
||||
generror("Undefined symbol");
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/* Fixup jmpslot so future calls transfer directly to target */
|
||||
addr = np->nz_value;
|
||||
if (src_map)
|
||||
addr += (long)src_map->som_addr;
|
||||
|
@ -27,7 +27,7 @@
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* $Id: link.h,v 1.12 1997/05/07 02:26:34 eivind Exp $
|
||||
* $Id: link.h,v 1.13 1997/05/07 20:00:00 eivind Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -167,6 +167,7 @@ struct so_debug {
|
||||
*/
|
||||
#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
|
||||
#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
|
||||
#define LDSO_VERSION_HAS_DLSYM3 2 /* includes 3-argument dlsym */
|
||||
|
||||
/*
|
||||
* Entry points into ld.so - user interface to the run-time linker.
|
||||
@ -179,6 +180,7 @@ struct ld_entry {
|
||||
void *(*dlsym) __P((void *, char *)); /* NONE */
|
||||
char *(*dlerror) __P((void)); /* NONE */
|
||||
void (*dlexit) __P((void)); /* HAS_DLEXIT */
|
||||
void *(*dlsym3) __P((void *, char *, void *)); /* HAS_DLSYM3 */
|
||||
};
|
||||
|
||||
/*
|
||||
|
@ -27,7 +27,7 @@
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* $Id: link.h,v 1.12 1997/05/07 02:26:34 eivind Exp $
|
||||
* $Id: link.h,v 1.13 1997/05/07 20:00:00 eivind Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -167,6 +167,7 @@ struct so_debug {
|
||||
*/
|
||||
#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
|
||||
#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
|
||||
#define LDSO_VERSION_HAS_DLSYM3 2 /* includes 3-argument dlsym */
|
||||
|
||||
/*
|
||||
* Entry points into ld.so - user interface to the run-time linker.
|
||||
@ -179,6 +180,7 @@ struct ld_entry {
|
||||
void *(*dlsym) __P((void *, char *)); /* NONE */
|
||||
char *(*dlerror) __P((void)); /* NONE */
|
||||
void (*dlexit) __P((void)); /* HAS_DLEXIT */
|
||||
void *(*dlsym3) __P((void *, char *, void *)); /* HAS_DLSYM3 */
|
||||
};
|
||||
|
||||
/*
|
||||
|
Loading…
Reference in New Issue
Block a user