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When checking to see whether a needed shared library has already

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been loaded, look for a match by device and inode number if the
traditional pathname comparisons don't find a match.  This detects
the case in which a library is requested using two different names
which are really links to the same file, and avoids loading it
twice.

Requested by:	peter@freebsd.org
Reviewed by:	peter@freebsd.org
This commit is contained in:
John Polstra 1996-05-22 06:34:12 +00:00
parent 602cb7a629
commit 1dd43c183e
2 changed files with 72 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
gnu/usr.bin/ld/rtld/rtld.c
View File

@ -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: rtld.c,v 1.32 1996/01/13 00:15:25 jdp Exp $
* $Id: rtld.c,v 1.33 1996/04/20 18:29:50 jdp Exp $
*/
#include <sys/param.h>
@ -88,6 +88,8 @@ struct somap_private {
struct so_map *spd_parent;
struct so_list *spd_children;
struct so_map *spd_prev;
dev_t spd_dev;
ino_t spd_ino;
int spd_refcount;
int spd_flags;
#define RTLD_MAIN 0x01
@ -491,17 +493,41 @@ map_object(path, sodp, parent)
struct so_map *parent;
{
struct so_map *smp;
struct stat statbuf;
if(path == NULL) /* Special case for the main program itself */
smp = link_map_head;
else {
/* Check whether the shared object is already mapped */
/*
* Check whether the shared object is already mapped.
* We check first for an exact match by pathname. That
* will detect the usual case. If no match is found by
* pathname, then stat the file, and check for a match by
* device and inode. That will detect the less common case
* involving multiple links to the same library.
*/
for(smp = link_map_head; smp != NULL; smp = smp->som_next) {
if(!(LM_PRIVATE(smp)->spd_flags & (RTLD_MAIN|RTLD_RTLD))
&& smp->som_path != NULL
&& strcmp(smp->som_path, path) == 0)
break;
}
if(smp == NULL) { /* Check for a match by device and inode */
if (stat(path, &statbuf) == -1) {
generror ("cannot stat \"%s\" : %s",
path, strerror(errno));
return NULL;
}
for (smp = link_map_head; smp != NULL;
smp = smp->som_next) {
struct somap_private *smpp = LM_PRIVATE(smp);
if (!(smpp->spd_flags & (RTLD_MAIN | RTLD_RTLD))
&& smpp->spd_ino == statbuf.st_ino
&& smpp->spd_dev == statbuf.st_dev)
break;
}
}
}
if (smp == NULL) { /* We must map the object */
@ -589,6 +615,14 @@ map_object(path, sodp, parent)
smpp->a_text = hdr.a_text;
smpp->a_data = hdr.a_data;
smpp->a_bss = hdr.a_bss;
/*
* Save the device and inode, so we can detect multiple links
* to the same library. Note, if we reach this point, then
* statbuf is guaranteed to have been filled in.
*/
smpp->spd_dev = statbuf.st_dev;
smpp->spd_ino = statbuf.st_ino;
}
LM_PRIVATE(smp)->spd_refcount++;

38
libexec/rtld-aout/rtld.c
View File

@ -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: rtld.c,v 1.32 1996/01/13 00:15:25 jdp Exp $
* $Id: rtld.c,v 1.33 1996/04/20 18:29:50 jdp Exp $
*/
#include <sys/param.h>
@ -88,6 +88,8 @@ struct somap_private {
struct so_map *spd_parent;
struct so_list *spd_children;
struct so_map *spd_prev;
dev_t spd_dev;
ino_t spd_ino;
int spd_refcount;
int spd_flags;
#define RTLD_MAIN 0x01
@ -491,17 +493,41 @@ map_object(path, sodp, parent)
struct so_map *parent;
{
struct so_map *smp;
struct stat statbuf;
if(path == NULL) /* Special case for the main program itself */
smp = link_map_head;
else {
/* Check whether the shared object is already mapped */
/*
* Check whether the shared object is already mapped.
* We check first for an exact match by pathname. That
* will detect the usual case. If no match is found by
* pathname, then stat the file, and check for a match by
* device and inode. That will detect the less common case
* involving multiple links to the same library.
*/
for(smp = link_map_head; smp != NULL; smp = smp->som_next) {
if(!(LM_PRIVATE(smp)->spd_flags & (RTLD_MAIN|RTLD_RTLD))
&& smp->som_path != NULL
&& strcmp(smp->som_path, path) == 0)
break;
}
if(smp == NULL) { /* Check for a match by device and inode */
if (stat(path, &statbuf) == -1) {
generror ("cannot stat \"%s\" : %s",
path, strerror(errno));
return NULL;
}
for (smp = link_map_head; smp != NULL;
smp = smp->som_next) {
struct somap_private *smpp = LM_PRIVATE(smp);
if (!(smpp->spd_flags & (RTLD_MAIN | RTLD_RTLD))
&& smpp->spd_ino == statbuf.st_ino
&& smpp->spd_dev == statbuf.st_dev)
break;
}
}
}
if (smp == NULL) { /* We must map the object */
@ -589,6 +615,14 @@ map_object(path, sodp, parent)
smpp->a_text = hdr.a_text;
smpp->a_data = hdr.a_data;
smpp->a_bss = hdr.a_bss;
/*
* Save the device and inode, so we can detect multiple links
* to the same library. Note, if we reach this point, then
* statbuf is guaranteed to have been filled in.
*/
smpp->spd_dev = statbuf.st_dev;
smpp->spd_ino = statbuf.st_ino;
}
LM_PRIVATE(smp)->spd_refcount++;