glibc/sysdeps/unix/sysv/linux/dl-origin.c
Ulrich Drepper 42fa1f67d4 * sysdeps/unix/sysv/linux/dl-origin.c (_dl_get_origin): We cannot
use the AT_EXECFN value if it is no absolute path.
	* sysdeps/unix/sysv/linux/kernel-features.h: Never define
	__ASSUME_AT_EXECFN.
2008-08-01 18:03:57 +00:00

95 lines
2.6 KiB
C

/* Find path of executable.
Copyright (C) 1998-2000, 2002, 2004, 2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <ldsodefs.h>
#include <sysdep.h>
#include <dl-dst.h>
/* On Linux >= 2.1 systems which have the dcache implementation we can get
the path of the application from the /proc/self/exe symlink. Try this
first and fall back on the generic method if necessary. */
const char *
_dl_get_origin (void)
{
char linkval[PATH_MAX];
const char *str;
char *result = (char *) -1l;
int len;
str = GLRO(dl_execfn);
if (str == NULL || str[0] != '/')
{
INTERNAL_SYSCALL_DECL (err);
len = INTERNAL_SYSCALL (readlink, err, 3, "/proc/self/exe", linkval,
sizeof (linkval));
if (! INTERNAL_SYSCALL_ERROR_P (len, err)
&& len > 0 && linkval[0] != '[')
str = linkval;
else
str = NULL;
}
else
len = strlen (str);
if (str == NULL)
{
/* We use the environment variable LD_ORIGIN_PATH. If it is set make
a copy and strip out trailing slashes. */
if (GLRO(dl_origin_path) != NULL)
{
size_t len = strlen (GLRO(dl_origin_path));
result = (char *) malloc (len + 1);
if (result == NULL)
result = (char *) -1;
else
{
char *cp = __mempcpy (result, GLRO(dl_origin_path), len);
while (cp > result + 1 && cp[-1] == '/')
--cp;
*cp = '\0';
}
}
}
else
{
/* We can use this value. */
assert (str[0] == '/');
while (len > 1 && str[len - 1] != '/')
--len;
result = (char *) malloc (len + 1);
if (result == NULL)
result = (char *) -1;
else if (len == 1)
memcpy (result, "/", 2);
else
*((char *) __mempcpy (result, str, len - 1)) = '\0';
}
return result;
}