NetBSD-5.0.2/lib/csu/common_aout/common.c
/* $NetBSD: common.c,v 1.20 2008/04/28 20:22:54 martin Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Kranenburg.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifdef DYNAMIC
typedef int (*rtld_entry_fn) __P((int, struct crt_ldso *));
static struct ld_entry **ld_entry;
static void
__load_rtld(dp)
struct _dynamic *dp;
{
static struct crt_ldso crt;
struct exec hdr;
rtld_entry_fn entry;
#if defined(sun) && defined(DUPZFD)
int dupzfd;
#endif
#ifdef DEBUG
/* Provision for alternate ld.so - security risk! */
if ((crt.crt_ldso = _getenv("LDSO")) == NULL)
#endif
crt.crt_ldso = LDSO;
crt.crt_ldfd = open(crt.crt_ldso, 0, 0);
if (crt.crt_ldfd == -1) {
_FATAL("No ld.so\n");
}
/* Read LDSO exec header */
if (read(crt.crt_ldfd, &hdr, sizeof hdr) < sizeof hdr) {
_FATAL("Failure reading ld.so\n");
}
if (N_GETMAGIC(hdr) != ZMAGIC && N_GETMAGIC(hdr) != QMAGIC) {
_FATAL("Bad magic: ld.so\n");
}
#ifdef sun
/* Get bucket of zeroes */
crt.crt_dzfd = open("/dev/zero", 0, 0);
if (crt.crt_dzfd == -1) {
_FATAL("No /dev/zero\n");
}
#endif
#ifdef __NetBSD__
/* We use MAP_ANON */
crt.crt_dzfd = -1;
#endif
#if defined(sun) && defined(DUPZFD)
if ((dupzfd = dup(crt.crt_dzfd)) < 0) {
_FATAL("Cannot dup /dev/zero\n");
}
#endif
/* Map in ld.so */
crt.crt_ba = mmap(0, hdr.a_text+hdr.a_data+hdr.a_bss,
PROT_READ|PROT_EXEC,
MAP_FILE|MAP_PRIVATE,
crt.crt_ldfd, N_TXTOFF(hdr));
if (crt.crt_ba == -1) {
_FATAL("Cannot map ld.so\n");
}
#ifdef __NetBSD__
/* !!!
* This is gross, ld.so is a ZMAGIC a.out, but has `sizeof(hdr)' for
* an entry point and not at PAGSIZ as the N_*ADDR macros assume.
*/
#undef N_DATADDR
#undef N_BSSADDR
#define N_DATADDR(x) ((x).a_text)
#define N_BSSADDR(x) ((x).a_text + (x).a_data)
#endif
/* Map in data segment of ld.so writable */
if (mmap(crt.crt_ba+N_DATADDR(hdr), hdr.a_data,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_FILE|MAP_PRIVATE|MAP_FIXED,
crt.crt_ldfd, N_DATOFF(hdr)) == -1) {
_FATAL("Cannot map ld.so\n");
}
/* Map bss segment of ld.so zero */
if (hdr.a_bss && mmap(crt.crt_ba+N_BSSADDR(hdr), hdr.a_bss,
PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE|MAP_FIXED,
crt.crt_dzfd, 0) == -1) {
_FATAL("Cannot map ld.so\n");
}
crt.crt_dp = dp;
crt.crt_ep = environ;
crt.crt_bp = (caddr_t)_callmain;
crt.crt_prog = __progname;
#ifdef sun
/* Call Sun's ld.so entry point: version 1, offset crt */
__call(CRT_VERSION_SUN, &crt, crt.crt_ba + sizeof hdr);
#else
ld_entry = &crt.crt_ldentry;
entry = (rtld_entry_fn)(crt.crt_ba + sizeof hdr);
if ((*entry)(CRT_VERSION_BSD_4, &crt) == -1) {
/* Feeble attempt to deal with out-dated ld.so */
#ifdef __STDC__
# define str "crt0: update " LDSO "\n"
#else
# define str "crt0: update ld.so\n"
#endif
(void)write(2, str, sizeof(str)-1);
# undef str
if ((*entry)(CRT_VERSION_BSD_3, &crt) == -1) {
_FATAL("ld.so failed\n");
}
ld_entry = &dp->d_entry;
return;
}
atexit((*ld_entry)->dlexit);
#endif
#if defined(sun) && defined(DUPZFD)
if (dup2(dupzfd, crt.crt_dzfd) < 0) {
_FATAL("Cannot dup2 /dev/zero\n");
}
(void)close(dupzfd);
#endif
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;
return ((*ld_entry)->dlsym)(fd, name);
}
int
dlctl(fd, cmd, arg)
void *fd, *arg;
int cmd;
{
if ((*ld_entry) == NULL)
return -1;
return ((*ld_entry)->dlctl)(fd, cmd, arg);
}
__aconst char *
dlerror()
{
int error;
if ((*ld_entry) == NULL ||
(*(*ld_entry)->dlctl)(NULL, DL_GETERRNO, &error) == -1)
return "Service unavailable";
return ((char *)(error == 0 ? NULL : strerror(error)));
}
int
dladdr(addr, dli)
const void *addr;
Dl_info *dli;
{
if ((*ld_entry) == NULL || (*ld_entry)->dladdr == NULL)
return (0);
return ((*ld_entry)->dladdr)(addr, dli);
}
/*
* Support routines
*/
#ifdef DEBUG
static int
_strncmp(s1, s2, n)
char *s1, *s2;
int n;
{
if (n == 0)
return (0);
do {
if (*s1 != *s2++)
return (*(unsigned char *)s1 - *(unsigned char *)--s2);
if (*s1++ == 0)
break;
} while (--n != 0);
return (0);
}
static char *
_getenv(name)
char *name;
{
extern char **environ;
int len;
char **P, *C;
for (C = name, len = 0; *C && *C != '='; ++C, ++len);
for (P = environ; *P; ++P)
if (!_strncmp(*P, name, len))
if (*(C = *P + len) == '=') {
return(++C);
}
return (char *)0;
}
#endif
static char *
_strrchr(p, ch)
char *p, ch;
{
char *save;
for (save = NULL;; ++p) {
if (*p == ch)
save = (char *)p;
if (!*p)
return(save);
}
/* NOTREACHED */
}
#endif /* DYNAMIC */