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/* Operating system support for run-time dynamic linker. Generic Unix version.
Copyright (C) 1995, 96 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <elf.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <link.h>
#include <unistd.h>
#include <stdarg.h>
#include <string.h>
extern int _dl_argc;
extern char **_dl_argv;
extern char **_environ;
extern void _start (void);
int __libc_enable_secure;
ElfW(Addr)
_dl_sysdep_start (void **start_argptr,
void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
ElfW(Addr) *user_entry))
{
const ElfW(Phdr) *phdr;
ElfW(Word) phnum;
ElfW(Addr) user_entry;
ElfW(auxv_t) *av;
uid_t uid, euid;
gid_t gid, egid;
unsigned int seen;
user_entry = (ElfW(Addr)) &_start;
_dl_argc = *(long *) start_argptr;
_dl_argv = (char **) start_argptr + 1;
_environ = &_dl_argv[_dl_argc + 1];
start_argptr = (void **) _environ;
while (*start_argptr)
++start_argptr;
seen = 0;
#define M(type) (1 << (type))
for (av = (void *) ++start_argptr;
av->a_type != AT_NULL;
seen |= M ((++av)->a_type))
switch (av->a_type)
{
case AT_PHDR:
phdr = av->a_un.a_ptr;
break;
case AT_PHNUM:
phnum = av->a_un.a_val;
break;
case AT_ENTRY:
user_entry = av->a_un.a_val;
break;
case AT_UID:
uid = av->a_un.a_val;
break;
case AT_GID:
gid = av->a_un.a_val;
break;
case AT_EUID:
euid = av->a_un.a_val;
break;
case AT_EGID:
egid = av->a_un.a_val;
break;
}
/* Linux doesn't provide us with any of these values on the stack
when the dynamic linker is run directly as a program. */
#define SEE(UID, uid) if ((seen & M (AT_##UID)) == 0) uid = __get##uid ()
SEE (UID, uid);
SEE (GID, gid);
SEE (EUID, euid);
SEE (EGID, egid);
__libc_enable_secure = uid != euid || gid != egid;
#ifdef DL_SYSDEP_INIT
DL_SYSDEP_INIT;
#endif
(*dl_main) (phdr, phnum, &user_entry);
return user_entry;
}
void
_dl_sysdep_start_cleanup (void)
{
}
#ifndef MAP_ANON
/* This is only needed if the system doesn't support MAP_ANON. */
int
_dl_sysdep_open_zero_fill (void)
{
return __open ("/dev/zero", O_RDONLY);
}
#endif
/* Read the whole contents of FILE into new mmap'd space with given
protections. *SIZEP gets the size of the file. */
void *
_dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot)
{
void *result;
struct stat st;
int fd = __open (file, O_RDONLY);
if (fd < 0)
return NULL;
if (__fstat (fd, &st) < 0)
result = NULL;
else
{
/* Map a copy of the file contents. */
result = __mmap (0, st.st_size, prot,
#ifdef MAP_COPY
MAP_COPY
#else
MAP_PRIVATE
#endif
#ifdef MAP_FILE
| MAP_FILE
#endif
, fd, 0);
if (result == (void *) -1)
result = NULL;
else
*sizep = st.st_size;
}
__close (fd);
return result;
}
void
_dl_sysdep_fatal (const char *msg, ...)
{
va_list ap;
va_start (ap, msg);
do
{
size_t len = strlen (msg);
__write (STDERR_FILENO, msg, len);
msg = va_arg (ap, const char *);
} while (msg);
va_end (ap);
_exit (127);
}
void
_dl_sysdep_message (const char *msg, ...)
{
va_list ap;
va_start (ap, msg);
do
{
size_t len = strlen (msg);
__write (STDOUT_FILENO, msg, len);
msg = va_arg (ap, const char *);
} while (msg);
va_end (ap);
}
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