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Change ld.so to correctly load dependant libraries for dlopen and unload them

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on dlclose.  Also correctly call constructors and destructors for libraries
linked with /usr/lib/c++rt0.o.
Change interpretation of dlopen manpage to call _init() rather than init()
for dlopened objects.
Change c++rt0.o to avoid using atexit to call destructors, allowing dlclose to
call destructors when an object is unloaded.
Change interface between crt0 and ld.so to allow crt0 to call a function on
exit to call destructors for shared libraries explicitly.

These changes are backwards compatible.  Old binaries will work with the new
ld.so and new binaries will work with the old ld.so.  A version number has
been introduced in the crt0-ld.so interface to allow for future changes.

Reviewed by:	GAWollman, Craig Struble <cstruble@singularity.bevc.blacksburg.va.us>
This commit is contained in:
Doug Rabson 1995-06-27 09:53:27 +00:00
parent 524743b0fe
commit 82aaeb09ad
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=9335
7 changed files with 526 additions and 154 deletions
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300
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 1.23 1995/04/21 04:57:50 nate Exp $
* $Id: rtld.c,v 1.24 1995/05/30 05:01:49 rgrimes Exp $
*/
#include <sys/param.h>
@ -83,6 +83,7 @@ struct somap_private {
#define RTLD_MAIN 1
#define RTLD_RTLD 2
#define RTLD_DL 4
#define RTLD_INIT 8
unsigned long a_text; /* text size, if known */
unsigned long a_data; /* initialized data size */
unsigned long a_bss; /* uninitialized data size */
@ -159,9 +160,10 @@ static void *__dlopen __P((char *, int));
static int __dlclose __P((void *));
static void *__dlsym __P((void *, char *));
static char *__dlerror __P((void));
static void __dlexit __P((void));
static struct ld_entry ld_entry = {
__dlopen, __dlclose, __dlsym, __dlerror
__dlopen, __dlclose, __dlsym, __dlerror, __dlexit
};
void xprintf __P((char *, ...));
@ -169,6 +171,9 @@ static void load_objects __P(( struct crt_ldso *,
struct _dynamic *));
static struct so_map *map_object __P((struct sod *, struct so_map *));
static int unmap_object __P((struct so_map *));
static struct so_map *load_object __P((struct sod *, struct so_map *,
int, int));
static int unload_object __P((struct so_map *));
static struct so_map *alloc_link_map __P(( char *, struct sod *,
struct so_map *, caddr_t,
struct _dynamic *));
@ -177,7 +182,8 @@ static inline int check_text_reloc __P(( struct relocation_info *,
caddr_t));
static int reloc_map __P((struct so_map *));
static void reloc_copy __P((struct so_map *));
static void init_map __P((struct so_map *, char *));
static void init_map __P((struct so_map *, char *, int));
static void call_map __P((struct so_map *, char *));
static char *rtfindlib __P((char *, int, int, int *));
void binder_entry __P((void));
long binder __P((jmpslot_t *));
@ -289,7 +295,7 @@ struct _dynamic *dp;
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
init_map(smp, ".init");
init_map(smp, ".init", 0);
}
/* Fill in some field in main's __DYNAMIC structure */
@ -323,7 +329,7 @@ struct _dynamic *dp;
/* Close our file descriptor */
(void)close(crtp->crt_ldfd);
anon_close();
return 0;
return LDSO_VERSION_HAS_DLEXIT;
}
@ -459,6 +465,42 @@ alloc_link_map(path, sodp, parent, addr, dp)
return smp;
}
static struct so_map *
find_object(sodp, smp)
struct sod *sodp;
struct so_map *smp;
{
char *path, *name = (char *)(sodp->sod_name + LM_LDBASE(smp));
int usehints = 0;
struct so_map *p;
if (sodp->sod_library) {
usehints = 1;
again:
path = rtfindlib(name, sodp->sod_major,
sodp->sod_minor, &usehints);
if (path == NULL) {
generror ("Can't find shared library \"%s\"",
name);
return NULL;
}
} else {
if (careful && *name != '/') {
generror ("Shared library path must start with \"/\" for \"%s\"",
name);
return NULL;
}
path = name;
}
/* Check if already loaded */
for (p = link_map_head; p; p = p->som_next)
if (p->som_path && strcmp(p->som_path, path) == 0)
break;
return p;
}
/*
* Map object identified by link object LOP which was found
* in link map LMP.
@ -612,8 +654,7 @@ unmap_object(smp)
return -1;
}
}
free((caddr_t) smp->som_sod->sod_name);
free(smp->som_sod);
if (smp->som_path) free(smp->som_path);
free(smp);
return 0;
}
@ -763,7 +804,42 @@ reloc_copy(smp)
}
static void
init_map(smp, sym)
init_map(smp, sym, dependants)
struct so_map *smp;
char *sym;
int dependants;
{
struct so_map *src_map = smp;
struct nzlist *np;
if (LM_PRIVATE(smp)->spd_flags & RTLD_INIT)
return;
LM_PRIVATE(smp)->spd_flags |= RTLD_INIT;
if (dependants) {
struct sod *sodp;
struct so_map *smp2;
long next;
next = LD_NEED(smp->som_dynamic);
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
smp2 = find_object(sodp, smp);
if (smp2)
init_map(smp2, sym, dependants);
next = sodp->sod_next;
}
}
np = lookup(sym, &src_map, 1);
if (np)
(*(void (*)())(src_map->som_addr + np->nz_value))();
}
static void
call_map(smp, sym)
struct so_map *smp;
char *sym;
{
@ -775,6 +851,119 @@ init_map(smp, sym)
(*(void (*)())(src_map->som_addr + np->nz_value))();
}
/*
* Load an object with all its dependant objects, recording the type of the
* object and optionally calling its init function.
*/
static struct so_map *
load_object(sodp, parent, type, init)
struct sod *sodp;
struct so_map *parent;
int type;
int init;
{
struct so_map* smp;
/*
* Find or map the object.
*/
smp = map_object(sodp, parent);
if (smp == NULL) return NULL;
/*
* The first time the object is mapped, load it's dependant objects and
* relocate it.
*/
if (LM_PRIVATE(smp)->spd_refcount++ == 0) {
struct sod *sodp;
struct so_map *smp2;
long next;
next = LD_NEED(smp->som_dynamic);
/*
* Load dependant objects but defer initialisation until later.
* When all the dependants (and sub dependants, etc.) have been
* loaded and relocated, it is safe to call the init functions,
* using a recursive call to init_map. This ensures that if init
* code in the dependants calls code in the parent, it will work
* as expected.
*/
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
/*
* Dependant objects (of both dlopen and main) don't get a
* specific type.
*/
if ((smp2 = load_object(sodp, smp, 0, 0)) == NULL) {
#ifdef DEBUG
xprintf("ld.so: map_object failed on cascaded %s %s (%d.%d): %s\n",
smp->sod_library ? "library" : "file", smp->sod_name,
smp->sod_major, smp->sod_minor, strerror(errno));
#endif
unload_object(smp);
return NULL;
}
next = sodp->sod_next;
}
LM_PRIVATE(smp)->spd_flags |= type;
if (reloc_map(smp) < 0) {
unload_object(smp);
return NULL;
}
reloc_copy(smp);
if (init) {
init_map(smp, ".init", 1);
}
}
return smp;
}
/*
* Unload an object, recursively unloading dependant objects.
*/
static int
unload_object(smp)
struct so_map *smp;
{
struct so_map *smp2;
struct sod *sodp;
long next;
if (--LM_PRIVATE(smp)->spd_refcount != 0)
return -1;
/*
* Call destructors for the object (before unloading its dependants
* since destructors may use them. Only call destructors if constructors
* have been called.
*/
if (LM_PRIVATE(smp)->spd_flags & RTLD_INIT)
call_map(smp, ".fini");
/*
* Unmap any dependant objects first.
*/
next = LD_NEED(smp->som_dynamic);
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
smp2 = find_object(sodp, smp);
if (smp2)
unload_object(smp2);
next = sodp->sod_next;
}
/*
* Remove from address space.
*/
if (unmap_object(smp) < 0)
return -1;
return 0;
}
/*
* Run-time common symbol table.
*/
@ -1262,6 +1451,7 @@ static struct so_map dlmap = {
static char dlerror_buf [DLERROR_BUF_SIZE];
static char *dlerror_msg = NULL;
static void *
__dlopen(name, mode)
char *name;
@ -1286,24 +1476,19 @@ __dlopen(name, mode)
sodp->sod_library = 0;
sodp->sod_major = sodp->sod_minor = 0;
if ((smp = map_object(sodp, &dlmap)) == NULL) {
if ((smp = load_object(sodp, &dlmap, RTLD_DL, 1)) == NULL) {
#ifdef DEBUG
xprintf("%s: %s\n", name, dlerror_buf);
#endif
return NULL;
}
if (dl_cascade(smp) == 0)
return NULL;
if (LM_PRIVATE(smp)->spd_refcount++ == 0) {
LM_PRIVATE(smp)->spd_flags |= RTLD_DL;
if (reloc_map(smp) < 0)
return NULL;
reloc_copy(smp);
init_map(smp, ".init");
init_map(smp, "_init");
}
/*
* If this was newly loaded, call the _init() function in the
* object as per manpage.
*/
if (LM_PRIVATE(smp)->spd_refcount == 1)
call_map(smp, "__init");
return smp;
}
@ -1318,13 +1503,25 @@ __dlclose(fd)
xprintf("dlclose(%s): refcount = %d\n", smp->som_path,
LM_PRIVATE(smp)->spd_refcount);
#endif
if (--LM_PRIVATE(smp)->spd_refcount != 0)
return 0;
/* Dismantle shared object map and descriptor */
init_map(smp, "_fini");
if (smp == NULL) {
generror("NULL argument to dlclose");
return -1;
}
if (unmap_object(smp) < 0)
if (LM_PRIVATE(smp)->spd_refcount > 1) {
LM_PRIVATE(smp)->spd_refcount--;
return 0;
}
/*
* Call the function _fini() in the object as per manpage.
*/
call_map(smp, "__fini");
free((void*) smp->som_sod->sod_name);
free(smp->som_sod);
if (unload_object(smp) < 0)
return -1;
return 0;
@ -1369,6 +1566,18 @@ __dlerror __P((void))
return err;
}
static void
__dlexit __P((void))
{
struct so_map *smp;
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & (RTLD_RTLD|RTLD_MAIN))
continue;
call_map(smp, ".fini");
}
}
/*
* Generate an error message that can be later be retrieved via dlerror.
*/
@ -1413,44 +1622,3 @@ char *fmt;
va_end(ap);
}
static int
dl_cascade(smp)
struct so_map *smp;
{
struct sod *sodp;
struct so_map *smp2;
long next;
next = LD_NEED(smp->som_dynamic);
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
if ((smp2 = map_object(sodp, smp)) == NULL) {
#ifdef DEBUG
xprintf("ld.so: map_object failed on cascaded %s %s (%d.%d): %s\n",
smp->sod_library ? "library" : "file", smp->sod_name,
smp->sod_major, smp->sod_minor, strerror(errno));
#endif
return 0;
}
#if 0
/*
* XXX - this doesn't work for some reason. not
* at all sure why. -mrg
*/
if (dl_cascade(smp2) == 0)
return 0;
#endif
if (LM_PRIVATE(smp2)->spd_refcount++ == 0) {
LM_PRIVATE(smp2)->spd_flags |= RTLD_DL;
reloc_map(smp2);
reloc_copy(smp2);
init_map(smp2, ".init");
init_map(smp2, "_init");
}
next = sodp->sod_next;
}
return 1;
}

20
include/link.h
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: link.h,v 1.3 1995/02/07 13:26:39 jkh Exp $
* $Id: link.h,v 1.4 1995/03/04 17:49:20 nate Exp $
*/
/*
@ -162,14 +162,23 @@ struct so_debug {
struct rt_symbol *dd_cc; /* Allocated commons/copied data */
};
/*
* Version returned to crt0 from ld.so
*/
#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
/*
* Entry points into ld.so - user interface to the run-time linker.
* Entries are valid for the given version numbers returned by ld.so
* to crt0.
*/
struct ld_entry {
void *(*dlopen) __P((char *, int));
int (*dlclose) __P((void *));
void *(*dlsym) __P((void *, char *));
char *(*dlerror) __P((void));
void *(*dlopen) __P((char *, int)); /* NONE */
int (*dlclose) __P((void *)); /* NONE */
void *(*dlsym) __P((void *, char *)); /* NONE */
char *(*dlerror) __P((void)); /* NONE */
void (*dlexit) __P((void)); /* HAS_DLEXIT */
};
/*
@ -246,7 +255,6 @@ struct crt_ldso {
#define CRT_VERSION_BSD_3 3
#define CRT_VERSION_BSD_4 4
/*
* Maximum number of recognized shared object version numbers.
*/

10
lib/csu/i386/c++rt0.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: c++rt0.c,v 1.1 1994/03/09 17:12:59 nate Exp $
* $Id: c++rt0.c,v 1.2 1995/05/30 05:39:36 rgrimes Exp $
*/
/*
@ -61,6 +61,7 @@ __ctors(void)
}
extern void __init() asm(".init");
extern void __fini() asm(".fini");
void
__init(void)
@ -74,7 +75,12 @@ __init(void)
if (!initialized) {
initialized = 1;
__ctors();
atexit(__dtors);
}
}
void
__fini(void)
{
__dtors();
}

10
lib/csu/i386/crt0.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: crt0.c,v 1.15 1995/02/07 13:27:29 jkh Exp $
* $Id: crt0.c,v 1.16 1995/02/24 07:51:13 phk Exp $
*/
@ -194,6 +194,7 @@ __do_dynamic_link ()
struct exec hdr;
char *ldso;
int (*entry)();
int ret;
#ifdef DEBUG
/* Provision for alternate ld.so - security risk! */
@ -259,11 +260,16 @@ __do_dynamic_link ()
crt.crt_prog = __progname;
entry = (int (*)())(crt.crt_ba + sizeof hdr);
if ((*entry)(CRT_VERSION_BSD_3, &crt) == -1) {
ret = (*entry)(CRT_VERSION_BSD_3, &crt);
if (ret == -1) {
_FATAL("ld.so failed\n");
}
ld_entry = _DYNAMIC.d_entry;
if (ret >= LDSO_VERSION_HAS_DLEXIT)
atexit(ld_entry->dlexit);
return;
}

300
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 1.23 1995/04/21 04:57:50 nate Exp $
* $Id: rtld.c,v 1.24 1995/05/30 05:01:49 rgrimes Exp $
*/
#include <sys/param.h>
@ -83,6 +83,7 @@ struct somap_private {
#define RTLD_MAIN 1
#define RTLD_RTLD 2
#define RTLD_DL 4
#define RTLD_INIT 8
unsigned long a_text; /* text size, if known */
unsigned long a_data; /* initialized data size */
unsigned long a_bss; /* uninitialized data size */
@ -159,9 +160,10 @@ static void *__dlopen __P((char *, int));
static int __dlclose __P((void *));
static void *__dlsym __P((void *, char *));
static char *__dlerror __P((void));
static void __dlexit __P((void));
static struct ld_entry ld_entry = {
__dlopen, __dlclose, __dlsym, __dlerror
__dlopen, __dlclose, __dlsym, __dlerror, __dlexit
};
void xprintf __P((char *, ...));
@ -169,6 +171,9 @@ static void load_objects __P(( struct crt_ldso *,
struct _dynamic *));
static struct so_map *map_object __P((struct sod *, struct so_map *));
static int unmap_object __P((struct so_map *));
static struct so_map *load_object __P((struct sod *, struct so_map *,
int, int));
static int unload_object __P((struct so_map *));
static struct so_map *alloc_link_map __P(( char *, struct sod *,
struct so_map *, caddr_t,
struct _dynamic *));
@ -177,7 +182,8 @@ static inline int check_text_reloc __P(( struct relocation_info *,
caddr_t));
static int reloc_map __P((struct so_map *));
static void reloc_copy __P((struct so_map *));
static void init_map __P((struct so_map *, char *));
static void init_map __P((struct so_map *, char *, int));
static void call_map __P((struct so_map *, char *));
static char *rtfindlib __P((char *, int, int, int *));
void binder_entry __P((void));
long binder __P((jmpslot_t *));
@ -289,7 +295,7 @@ struct _dynamic *dp;
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
init_map(smp, ".init");
init_map(smp, ".init", 0);
}
/* Fill in some field in main's __DYNAMIC structure */
@ -323,7 +329,7 @@ struct _dynamic *dp;
/* Close our file descriptor */
(void)close(crtp->crt_ldfd);
anon_close();
return 0;
return LDSO_VERSION_HAS_DLEXIT;
}
@ -459,6 +465,42 @@ alloc_link_map(path, sodp, parent, addr, dp)
return smp;
}
static struct so_map *
find_object(sodp, smp)
struct sod *sodp;
struct so_map *smp;
{
char *path, *name = (char *)(sodp->sod_name + LM_LDBASE(smp));
int usehints = 0;
struct so_map *p;
if (sodp->sod_library) {
usehints = 1;
again:
path = rtfindlib(name, sodp->sod_major,
sodp->sod_minor, &usehints);
if (path == NULL) {
generror ("Can't find shared library \"%s\"",
name);
return NULL;
}
} else {
if (careful && *name != '/') {
generror ("Shared library path must start with \"/\" for \"%s\"",
name);
return NULL;
}
path = name;
}
/* Check if already loaded */
for (p = link_map_head; p; p = p->som_next)
if (p->som_path && strcmp(p->som_path, path) == 0)
break;
return p;
}
/*
* Map object identified by link object LOP which was found
* in link map LMP.
@ -612,8 +654,7 @@ unmap_object(smp)
return -1;
}
}
free((caddr_t) smp->som_sod->sod_name);
free(smp->som_sod);
if (smp->som_path) free(smp->som_path);
free(smp);
return 0;
}
@ -763,7 +804,42 @@ reloc_copy(smp)
}
static void
init_map(smp, sym)
init_map(smp, sym, dependants)
struct so_map *smp;
char *sym;
int dependants;
{
struct so_map *src_map = smp;
struct nzlist *np;
if (LM_PRIVATE(smp)->spd_flags & RTLD_INIT)
return;
LM_PRIVATE(smp)->spd_flags |= RTLD_INIT;
if (dependants) {
struct sod *sodp;
struct so_map *smp2;
long next;
next = LD_NEED(smp->som_dynamic);
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
smp2 = find_object(sodp, smp);
if (smp2)
init_map(smp2, sym, dependants);
next = sodp->sod_next;
}
}
np = lookup(sym, &src_map, 1);
if (np)
(*(void (*)())(src_map->som_addr + np->nz_value))();
}
static void
call_map(smp, sym)
struct so_map *smp;
char *sym;
{
@ -775,6 +851,119 @@ init_map(smp, sym)
(*(void (*)())(src_map->som_addr + np->nz_value))();
}
/*
* Load an object with all its dependant objects, recording the type of the
* object and optionally calling its init function.
*/
static struct so_map *
load_object(sodp, parent, type, init)
struct sod *sodp;
struct so_map *parent;
int type;
int init;
{
struct so_map* smp;
/*
* Find or map the object.
*/
smp = map_object(sodp, parent);
if (smp == NULL) return NULL;
/*
* The first time the object is mapped, load it's dependant objects and
* relocate it.
*/
if (LM_PRIVATE(smp)->spd_refcount++ == 0) {
struct sod *sodp;
struct so_map *smp2;
long next;
next = LD_NEED(smp->som_dynamic);
/*
* Load dependant objects but defer initialisation until later.
* When all the dependants (and sub dependants, etc.) have been
* loaded and relocated, it is safe to call the init functions,
* using a recursive call to init_map. This ensures that if init
* code in the dependants calls code in the parent, it will work
* as expected.
*/
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
/*
* Dependant objects (of both dlopen and main) don't get a
* specific type.
*/
if ((smp2 = load_object(sodp, smp, 0, 0)) == NULL) {
#ifdef DEBUG
xprintf("ld.so: map_object failed on cascaded %s %s (%d.%d): %s\n",
smp->sod_library ? "library" : "file", smp->sod_name,
smp->sod_major, smp->sod_minor, strerror(errno));
#endif
unload_object(smp);
return NULL;
}
next = sodp->sod_next;
}
LM_PRIVATE(smp)->spd_flags |= type;
if (reloc_map(smp) < 0) {
unload_object(smp);
return NULL;
}
reloc_copy(smp);
if (init) {
init_map(smp, ".init", 1);
}
}
return smp;
}
/*
* Unload an object, recursively unloading dependant objects.
*/
static int
unload_object(smp)
struct so_map *smp;
{
struct so_map *smp2;
struct sod *sodp;
long next;
if (--LM_PRIVATE(smp)->spd_refcount != 0)
return -1;
/*
* Call destructors for the object (before unloading its dependants
* since destructors may use them. Only call destructors if constructors
* have been called.
*/
if (LM_PRIVATE(smp)->spd_flags & RTLD_INIT)
call_map(smp, ".fini");
/*
* Unmap any dependant objects first.
*/
next = LD_NEED(smp->som_dynamic);
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
smp2 = find_object(sodp, smp);
if (smp2)
unload_object(smp2);
next = sodp->sod_next;
}
/*
* Remove from address space.
*/
if (unmap_object(smp) < 0)
return -1;
return 0;
}
/*
* Run-time common symbol table.
*/
@ -1262,6 +1451,7 @@ static struct so_map dlmap = {
static char dlerror_buf [DLERROR_BUF_SIZE];
static char *dlerror_msg = NULL;
static void *
__dlopen(name, mode)
char *name;
@ -1286,24 +1476,19 @@ __dlopen(name, mode)
sodp->sod_library = 0;
sodp->sod_major = sodp->sod_minor = 0;
if ((smp = map_object(sodp, &dlmap)) == NULL) {
if ((smp = load_object(sodp, &dlmap, RTLD_DL, 1)) == NULL) {
#ifdef DEBUG
xprintf("%s: %s\n", name, dlerror_buf);
#endif
return NULL;
}
if (dl_cascade(smp) == 0)
return NULL;
if (LM_PRIVATE(smp)->spd_refcount++ == 0) {
LM_PRIVATE(smp)->spd_flags |= RTLD_DL;
if (reloc_map(smp) < 0)
return NULL;
reloc_copy(smp);
init_map(smp, ".init");
init_map(smp, "_init");
}
/*
* If this was newly loaded, call the _init() function in the
* object as per manpage.
*/
if (LM_PRIVATE(smp)->spd_refcount == 1)
call_map(smp, "__init");
return smp;
}
@ -1318,13 +1503,25 @@ __dlclose(fd)
xprintf("dlclose(%s): refcount = %d\n", smp->som_path,
LM_PRIVATE(smp)->spd_refcount);
#endif
if (--LM_PRIVATE(smp)->spd_refcount != 0)
return 0;
/* Dismantle shared object map and descriptor */
init_map(smp, "_fini");
if (smp == NULL) {
generror("NULL argument to dlclose");
return -1;
}
if (unmap_object(smp) < 0)
if (LM_PRIVATE(smp)->spd_refcount > 1) {
LM_PRIVATE(smp)->spd_refcount--;
return 0;
}
/*
* Call the function _fini() in the object as per manpage.
*/
call_map(smp, "__fini");
free((void*) smp->som_sod->sod_name);
free(smp->som_sod);
if (unload_object(smp) < 0)
return -1;
return 0;
@ -1369,6 +1566,18 @@ __dlerror __P((void))
return err;
}
static void
__dlexit __P((void))
{
struct so_map *smp;
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & (RTLD_RTLD|RTLD_MAIN))
continue;
call_map(smp, ".fini");
}
}
/*
* Generate an error message that can be later be retrieved via dlerror.
*/
@ -1413,44 +1622,3 @@ char *fmt;
va_end(ap);
}
static int
dl_cascade(smp)
struct so_map *smp;
{
struct sod *sodp;
struct so_map *smp2;
long next;
next = LD_NEED(smp->som_dynamic);
while (next) {
sodp = (struct sod *)(LM_LDBASE(smp) + next);
if ((smp2 = map_object(sodp, smp)) == NULL) {
#ifdef DEBUG
xprintf("ld.so: map_object failed on cascaded %s %s (%d.%d): %s\n",
smp->sod_library ? "library" : "file", smp->sod_name,
smp->sod_major, smp->sod_minor, strerror(errno));
#endif
return 0;
}
#if 0
/*
* XXX - this doesn't work for some reason. not
* at all sure why. -mrg
*/
if (dl_cascade(smp2) == 0)
return 0;
#endif
if (LM_PRIVATE(smp2)->spd_refcount++ == 0) {
LM_PRIVATE(smp2)->spd_flags |= RTLD_DL;
reloc_map(smp2);
reloc_copy(smp2);
init_map(smp2, ".init");
init_map(smp2, "_init");
}
next = sodp->sod_next;
}
return 1;
}

20
sys/sys/link_aout.h
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: link.h,v 1.3 1995/02/07 13:26:39 jkh Exp $
* $Id: link.h,v 1.4 1995/03/04 17:49:20 nate Exp $
*/
/*
@ -162,14 +162,23 @@ struct so_debug {
struct rt_symbol *dd_cc; /* Allocated commons/copied data */
};
/*
* Version returned to crt0 from ld.so
*/
#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
/*
* Entry points into ld.so - user interface to the run-time linker.
* Entries are valid for the given version numbers returned by ld.so
* to crt0.
*/
struct ld_entry {
void *(*dlopen) __P((char *, int));
int (*dlclose) __P((void *));
void *(*dlsym) __P((void *, char *));
char *(*dlerror) __P((void));
void *(*dlopen) __P((char *, int)); /* NONE */
int (*dlclose) __P((void *)); /* NONE */
void *(*dlsym) __P((void *, char *)); /* NONE */
char *(*dlerror) __P((void)); /* NONE */
void (*dlexit) __P((void)); /* HAS_DLEXIT */
};
/*
@ -246,7 +255,6 @@ struct crt_ldso {
#define CRT_VERSION_BSD_3 3
#define CRT_VERSION_BSD_4 4
/*
* Maximum number of recognized shared object version numbers.
*/

20
sys/sys/link_elf.h
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: link.h,v 1.3 1995/02/07 13:26:39 jkh Exp $
* $Id: link.h,v 1.4 1995/03/04 17:49:20 nate Exp $
*/
/*
@ -162,14 +162,23 @@ struct so_debug {
struct rt_symbol *dd_cc; /* Allocated commons/copied data */
};
/*
* Version returned to crt0 from ld.so
*/
#define LDSO_VERSION_NONE 0 /* FreeBSD2.0, 2.0.5 */
#define LDSO_VERSION_HAS_DLEXIT 1 /* includes dlexit in ld_entry */
/*
* Entry points into ld.so - user interface to the run-time linker.
* Entries are valid for the given version numbers returned by ld.so
* to crt0.
*/
struct ld_entry {
void *(*dlopen) __P((char *, int));
int (*dlclose) __P((void *));
void *(*dlsym) __P((void *, char *));
char *(*dlerror) __P((void));
void *(*dlopen) __P((char *, int)); /* NONE */
int (*dlclose) __P((void *)); /* NONE */
void *(*dlsym) __P((void *, char *)); /* NONE */
char *(*dlerror) __P((void)); /* NONE */
void (*dlexit) __P((void)); /* HAS_DLEXIT */
};
/*
@ -246,7 +255,6 @@ struct crt_ldso {
#define CRT_VERSION_BSD_3 3
#define CRT_VERSION_BSD_4 4
/*
* Maximum number of recognized shared object version numbers.
*/