glibc/sysdeps/unix/sysv/linux/dl-osinfo.h
Roland McGrath 5c7302ec1e revert
2005-03-31 02:14:52 +00:00

119 lines
3.4 KiB
C

/* Operating system specific code for generic dynamic loader functions. Linux.
Copyright (C) 2000,2001,2002,2004,2005 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 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 <string.h>
#include <fcntl.h>
#include <sys/sysctl.h>
#include <sys/utsname.h>
#include "kernel-features.h"
#include <dl-sysdep.h>
#ifndef MIN
# define MIN(a,b) (((a)<(b))?(a):(b))
#endif
#ifdef SHARED
/* This is the function used in the dynamic linker to print the fatal error
message. */
static inline void
__attribute__ ((__noreturn__))
dl_fatal (const char *str)
{
_dl_dprintf (2, str);
_exit (1);
}
#endif
static inline int __attribute__ ((always_inline))
_dl_discover_osversion (void)
{
char bufmem[64];
char *buf = bufmem;
unsigned int version;
int parts;
char *cp;
struct utsname uts;
/* Try the uname system call. */
if (__uname (&uts))
{
/* This was not successful. Now try reading the /proc filesystem. */
int fd = __open ("/proc/sys/kernel/osrelease", O_RDONLY);
if (fd < 0)
return -1;
ssize_t reslen = __read (fd, bufmem, sizeof (bufmem));
__close (fd);
if (reslen <= 0)
/* This also didn't work. We give up since we cannot
make sure the library can actually work. */
return -1;
buf[MIN (reslen, (ssize_t) sizeof (bufmem) - 1)] = '\0';
}
else
buf = uts.release;
/* Now convert it into a number. The string consists of at most
three parts. */
version = 0;
parts = 0;
cp = buf;
while ((*cp >= '0') && (*cp <= '9'))
{
unsigned int here = *cp++ - '0';
while ((*cp >= '0') && (*cp <= '9'))
{
here *= 10;
here += *cp++ - '0';
}
++parts;
version <<= 8;
version |= here;
if (*cp++ != '.')
/* Another part following? */
break;
}
if (parts < 3)
version <<= 8 * (3 - parts);
return version;
}
#define DL_SYSDEP_OSCHECK(FATAL) \
do { \
/* Test whether the kernel is new enough. This test is only performed \
if the library is not compiled to run on all kernels. */ \
\
int version = _dl_discover_osversion (); \
if (__builtin_expect (version >= 0, 1)) \
{ \
GLRO(dl_osversion) = version; \
\
/* Now we can test with the required version. */ \
if (__LINUX_KERNEL_VERSION > 0 && version < __LINUX_KERNEL_VERSION) \
/* Not sufficent. */ \
FATAL ("FATAL: kernel too old\n"); \
} \
else if (__LINUX_KERNEL_VERSION > 0) \
FATAL ("FATAL: cannot determine kernel version\n"); \
} while (0)