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Move the trampolines for dlopen and related functions from crt0.o

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into libc.  This reduces the size of every dynamically linked
executable by 248 bytes, and it reduces the size of static executables
by a lesser amount.  It also eliminates some global namespace
pollution.

With this change in place, the source for dlfcn.h should probably
be moved to "/usr/src/include".  I'll save that for another day.

Compatibility note:  Programs which use dlopen, if compiled on
systems with this change, will not run on systems with a libc from
prior to this change.  Very few programs use dlopen, so I think
that is OK.
This commit is contained in:
jdp 1998-02-09 06:05:25 +00:00
parent 7764f84ad9
commit 4538098d0b
6 changed files with 122 additions and 128 deletions
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6
lib/csu/i386/Makefile
View File

@ -1,13 +1,9 @@
# from: @(#)Makefile 5.6 (Berkeley) 5/22/91
# $Id: Makefile,v 1.33 1998/01/12 18:29:02 eivind Exp $
# $Id: Makefile,v 1.34 1998/02/06 16:46:31 jdp Exp $
CFLAGS+= -DLIBC_SCCS -fno-omit-frame-pointer -I${.CURDIR}
OBJS= crt0.o c++rt0.o gcrt0.o scrt0.o sgcrt0.o
CLEANFILES+= a.out
MAN3+= dladdr.3 dlopen.3
MLINKS+= dlopen.3 dlsym.3 \
dlopen.3 dlerror.3 \
dlopen.3 dlclose.3
all: ${OBJS}

136
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 1.31 1997/11/22 03:34:45 brian Exp $
* $Id: crt0.c,v 1.32 1998/02/06 16:46:33 jdp Exp $
*/
#include <sys/param.h>
@ -84,7 +84,6 @@ static int _strncmp();
#endif /* LDSO */
extern struct _dynamic _DYNAMIC;
static struct ld_entry *ld_entry;
static void __do_dynamic_link(char **argv);
#endif /* DYNAMIC */
@ -94,7 +93,9 @@ static char empty[1];
char *__progname = empty;
char **environ;
static int ldso_version;
/* Globals used by dlopen() and related functions in libc */
struct ld_entry *__ldso_entry;
int __ldso_version;
extern unsigned char etext;
extern unsigned char eprol asm ("eprol");
@ -257,22 +258,22 @@ __do_dynamic_link(argv)
crt.crt_argv = argv;
entry = (int (*)())(crt.crt_ba + sizeof hdr);
ldso_version = (*entry)(CRT_VERSION_BSD_5, &crt);
ld_entry = crt.crt_ldentry;
if (ldso_version == -1 && ld_entry == NULL) {
__ldso_version = (*entry)(CRT_VERSION_BSD_5, &crt);
__ldso_entry = crt.crt_ldentry;
if (__ldso_version == -1 && __ldso_entry == NULL) {
/* If version 5 not recognised, try version 4 */
ldso_version = (*entry)(CRT_VERSION_BSD_4, &crt);
ld_entry = crt.crt_ldentry;
if (ldso_version == -1 && ld_entry == NULL) {
__ldso_version = (*entry)(CRT_VERSION_BSD_4, &crt);
__ldso_entry = crt.crt_ldentry;
if (__ldso_version == -1 && __ldso_entry == NULL) {
/* if version 4 not recognised, try version 3 */
ldso_version = (*entry)(CRT_VERSION_BSD_3, &crt);
ld_entry = _DYNAMIC.d_entry;
__ldso_version = (*entry)(CRT_VERSION_BSD_3, &crt);
__ldso_entry = _DYNAMIC.d_entry;
}
}
if (ldso_version == -1) {
if (__ldso_version == -1) {
_PUTMSG("ld.so failed");
if (ld_entry != NULL) {
const char *msg = (ld_entry->dlerror)();
if (__ldso_entry != NULL) {
const char *msg = (__ldso_entry->dlerror)();
if(msg != NULL) {
const char *endp;
_PUTMSG(": ");
@ -285,73 +286,12 @@ __do_dynamic_link(argv)
}
if (ldso_version >= LDSO_VERSION_HAS_DLEXIT)
atexit(ld_entry->dlexit);
if (__ldso_version >= LDSO_VERSION_HAS_DLEXIT)
atexit(__ldso_entry->dlexit);
return;
}
/*
* DL stubs
*/
void *
dlopen(name, mode)
const char *name;
int mode;
{
if (ld_entry == NULL)
return NULL;
return (ld_entry->dlopen)(name, mode);
}
int
dlclose(fd)
void *fd;
{
if (ld_entry == NULL)
return -1;
return (ld_entry->dlclose)(fd);
}
void *
dlsym(fd, name)
void *fd;
const 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);
}
const char *
dlerror()
{
if (ld_entry == NULL)
return "Service unavailable";
return (ld_entry->dlerror)();
}
int
dladdr(addr, dlip)
const void *addr;
Dl_info *dlip;
{
if (ld_entry == NULL || ldso_version < LDSO_VERSION_HAS_DLADDR)
return 0;
return (ld_entry->dladdr)(addr, dlip);
}
/*
* Support routines
*/
@ -407,48 +347,6 @@ _getenv(name)
asm(" movl $-1,%eax");
asm(" ret");
#else /* DYNAMIC */
/*
* DL stubs for static linking case (just return error)
*/
void *
dlopen(name, mode)
const char *name;
int mode;
{
return NULL;
}
int
dlclose(fd)
void *fd;
{
return -1;
}
void *
dlsym(fd, name)
void *fd;
const char *name;
{
return NULL;
}
const char *
dlerror()
{
return "Service unavailable";
}
int
dladdr(addr, dlip)
const void *addr;
Dl_info *dlip;
{
return 0;
}
#endif /* DYNAMIC */

10
lib/libc/gen/Makefile.inc
View File

@ -1,5 +1,5 @@
# @(#)Makefile.inc 8.6 (Berkeley) 5/4/95
# $Id: Makefile.inc,v 1.40 1997/10/15 16:15:24 bde Exp $
# $Id: Makefile.inc,v 1.41 1997/10/21 08:41:06 bde Exp $
# machine-independent gen sources
.PATH: ${.CURDIR}/../libc/${MACHINE}/gen ${.CURDIR}/../libc/gen
@ -7,7 +7,7 @@
SRCS+= _rand48.c alarm.c arc4random.c assert.c \
clock.c closedir.c config.c confstr.c \
crypt.c ctermid.c daemon.c devname.c disklabel.c \
drand48.c erand48.c err.c errlst.c \
dlfcn.c drand48.c erand48.c err.c errlst.c \
exec.c fnmatch.c fstab.c fts.c getbootfile.c getbsize.c \
getcap.c getcwd.c getdomainname.c getgrent.c getgrouplist.c \
gethostname.c getloadavg.c getlogin.c getmntinfo.c getnetgrent.c \
@ -45,7 +45,8 @@ errlst.o errlst.po:
.if ${LIB} == "c"
MAN3+= alarm.3 arc4random.3 clock.3 config_open.3 \
confstr.3 crypt.3 ctermid.3 daemon.3 \
devname.3 directory.3 err.3 exec.3 fnmatch.3 frexp.3 fts.3 \
devname.3 directory.3 dladdr.3 dlopen.3 \
err.3 exec.3 fnmatch.3 frexp.3 fts.3 \
getbootfile.3 getbsize.3 getcap.3 getcwd.3 \
getdiskbyname.3 getdomainname.3 getfsent.3 \
getgrent.3 getgrouplist.3 gethostname.3 getloadavg.3 \
@ -69,6 +70,9 @@ MLINKS+=crypt.3 des_cipher.3 crypt.3 des_setkey.3 crypt.3 encrypt.3 \
MLINKS+=directory.3 closedir.3 directory.3 dirfd.3 directory.3 opendir.3 \
directory.3 readdir.3 directory.3 rewinddir.3 directory.3 seekdir.3 \
directory.3 telldir.3
MLINKS+=dlopen.3 dlsym.3 \
dlopen.3 dlerror.3 \
dlopen.3 dlclose.3
MLINKS+=exec.3 execl.3 exec.3 execle.3 exec.3 execlp.3 exec.3 exect.3 \
exec.3 execv.3 exec.3 execvp.3
MLINKS+=err.3 err_set_exit.3 err.3 err_set_file.3 err.3 errx.3 err.3 verr.3 \

2
lib/csu/i386/dladdr.3 → lib/libc/gen/dladdr.3
View File

@ -23,7 +23,7 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $Id$
.\" $Id: dladdr.3,v 1.1 1998/02/06 16:46:34 jdp Exp $
.\"
.Dd February 5, 1998
.Os FreeBSD

96
lib/libc/gen/dlfcn.c Normal file
View File

@ -0,0 +1,96 @@
/*-
* Copyright (c) 1998 John D. Polstra
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
/*
* Trampolines to services provided by the dynamic linker.
*/
#include <sys/types.h>
#include <nlist.h> /* XXX - Required by link.h */
#include <dlfcn.h>
#include <link.h>
#include <stddef.h>
/*
* These variables are set by code in crt0.o. For compatibility with
* old executables, they must be common, not extern.
*/
struct ld_entry *__ldso_entry; /* Entry points to dynamic linker */
int __ldso_version; /* Dynamic linker version number */
void *
dlopen(name, mode)
const char *name;
int mode;
{
if (__ldso_entry == NULL)
return NULL;
return (__ldso_entry->dlopen)(name, mode);
}
int
dlclose(fd)
void *fd;
{
if (__ldso_entry == NULL)
return -1;
return (__ldso_entry->dlclose)(fd);
}
void *
dlsym(fd, name)
void *fd;
const char *name;
{
if (__ldso_entry == NULL)
return NULL;
if (__ldso_version >= LDSO_VERSION_HAS_DLSYM3) {
void *retaddr = *(&fd - 1); /* XXX - ABI/machine dependent */
return (__ldso_entry->dlsym3)(fd, name, retaddr);
} else
return (__ldso_entry->dlsym)(fd, name);
}
const char *
dlerror()
{
if (__ldso_entry == NULL)
return "Service unavailable";
return (__ldso_entry->dlerror)();
}
int
dladdr(addr, dlip)
const void *addr;
Dl_info *dlip;
{
if (__ldso_entry == NULL || __ldso_version < LDSO_VERSION_HAS_DLADDR)
return 0;
return (__ldso_entry->dladdr)(addr, dlip);
}

0
lib/csu/i386/dlopen.3 → lib/libc/gen/dlopen.3
View File