glibc/sysdeps/unix/sysv/linux/configure.ac
Adhemerval Zanella b46d250656 Remove kernel version check
The kernel version check is used to avoid glibc to run on older
kernels where some syscall are not available and fallback code are
not enabled to handle graciously fail.  However, it does not prevent
if the kernel does not correctly advertise its version through
vDSO note, uname or procfs.

Also kernel version checks are sometime not desirable by users,
where they want to deploy on different system with different kernel
version knowing the minimum set of syscall is always presented on
such systems.

The kernel version check has been removed along with the
LD_ASSUME_KERNEL environment variable.  The minimum kernel used to
built glibc is still provided through NT_GNU_ABI_TAG ELF note and
also printed when libc.so is issued.

Checked on x86_64-linux-gnu.
2022-05-16 15:03:49 -03:00

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GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/unix/sysv/linux.
define([LIBC_LINUX_VERSION],[3.2.0])dnl
if test -n "$sysheaders"; then
OLD_CPPFLAGS=$CPPFLAGS
CPPFLAGS="$CPPFLAGS $SYSINCLUDES"
fi
define([libc_cv_linuxVER], [libc_cv_linux]patsubst(LIBC_LINUX_VERSION,[\.]))dnl
AC_CACHE_CHECK(installed Linux kernel header files, libc_cv_linuxVER, [dnl
AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[#include <linux/version.h>
#if !defined LINUX_VERSION_CODE || LINUX_VERSION_CODE < ]dnl
patsubst(LIBC_LINUX_VERSION,[^\([^.]*\)\.\([^.]*\)\.\([^.]*\)$],dnl
[ (\1 *65536+ \2 *256+ \3) /* \1.\2.\3 */])[
# error kernel headers missing or too old
#endif]], [[]])],
[libc_cv_linuxVER='LIBC_LINUX_VERSION or later'],
[libc_cv_linuxVER='missing or too old!'])])
if test "$libc_cv_linuxVER" != 'LIBC_LINUX_VERSION or later'; then
AC_MSG_ERROR([GNU libc requires kernel header files from
Linux LIBC_LINUX_VERSION or later to be installed before configuring.
The kernel header files are found usually in /usr/include/asm and
/usr/include/linux; make sure these directories use files from
Linux LIBC_LINUX_VERSION or later. This check uses <linux/version.h>, so
make sure that file was built correctly when installing the kernel header
files. To use kernel headers not from /usr/include/linux, use the
configure option --with-headers.])
fi
# If the user gave a minimal version number test whether the available
# kernel headers are young enough. Additionally we have minimal
# kernel versions for some architectures. If a previous configure fragment
# set arch_minimum_kernel already, let that override our defaults here.
# Note that we presume such a fragment has set libc_cv_gcc_unwind_find_fde
# if appropriate too.
test -n "$arch_minimum_kernel" || arch_minimum_kernel=3.2.0
if test -n "$minimum_kernel"; then
changequote(,)
user_version=$((`echo "$minimum_kernel.0.0.0" | sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/\1 \* 65536 + \2 \* 256 + \3/'`))
arch_version=$((`echo "$arch_minimum_kernel.0.0.0" | sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/\1 \* 65536 + \2 \* 256 + \3/'`))
changequote([,])
if test $user_version -lt $arch_version; then
AC_MSG_WARN([minimum kernel version reset to $arch_minimum_kernel])
minimum_kernel=$arch_minimum_kernel
fi
else
minimum_kernel=$arch_minimum_kernel
fi
AC_MSG_CHECKING(for kernel header at least $minimum_kernel)
changequote(,)dnl
decnum=`echo "$minimum_kernel.0.0.0" | sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/(\1 * 65536 + \2 * 256 + \3)/'`;
abinumstr=`echo "$minimum_kernel.0.0.0" | sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/\1.\2.\3/'`;
abinum=`echo "$minimum_kernel.0.0.0" | sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/\1,\2,\3/'`;
changequote([,])dnl
AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[#include <linux/version.h>
#if LINUX_VERSION_CODE < $decnum
# error kernel headers too old
#endif]], [[]])], [libc_minimum_kernel=ok], [libc_minimum_kernel='too old!'])
AC_MSG_RESULT($libc_minimum_kernel)
if test "$libc_minimum_kernel" = ok; then
AC_DEFINE_UNQUOTED(__LINUX_KERNEL_VERSION, $decnum)
AC_DEFINE_UNQUOTED(__LINUX_KERNEL_VERSION_STR, "$abinumstr")
AC_DEFINE_UNQUOTED(__ABI_TAG_VERSION, $abinum)
else
AC_MSG_ERROR([*** The available kernel headers are older than the requested
*** compatible kernel version])
fi
if test -n "$sysheaders"; then
CPPFLAGS=$OLD_CPPFLAGS
fi
if test "$prefix" = "/usr/local" -o "$prefix" = "/usr/local/" -o "$prefix" = "NONE"; then
if test $enable_sanity = yes; then
echo "\
*** On GNU/Linux systems the GNU C Library should not be installed into
*** /usr/local since this might make your system totally unusable.
*** We strongly advise to use a different prefix. For details read the FAQ.
*** If you really mean to do this, run configure again using the extra
*** parameter \`--disable-sanity-checks'."
exit 1
else
echo "\
*** WARNING: Do you really want to install the GNU C Library into /usr/local?
*** This might make your system totally unusable, for details read the FAQ."
fi
fi
# One Linux we use ldconfig.
use_ldconfig=yes
if test $host = $build; then
# If $prefix/include/{net,scsi} are symlinks, make install will
# clobber what they're linked to (probably a kernel tree).
# test -L ought to work on all Linux boxes.
if test "x$prefix" != xNONE; then
ac_prefix=$prefix
else
ac_prefix=$ac_default_prefix
fi
AC_MSG_CHECKING([for symlinks in ${ac_prefix}/include])
ac_message=
if test -L ${ac_prefix}/include/net; then
ac_message="$ac_message
${ac_prefix}/include/net is a symlink"
fi
if test -L ${ac_prefix}/include/scsi; then
ac_message="$ac_message
${ac_prefix}/include/scsi is a symlink"
fi
if test -n "$ac_message"; then
AC_MSG_ERROR([$ac_message
\`make install' will destroy the target of the link(s).
Delete the links and re-run configure, or better still, move the entire
${ac_prefix}/include directory out of the way.])
else
AC_MSG_RESULT(ok)
fi
fi
# We have inlined syscalls.
AC_DEFINE(HAVE_INLINED_SYSCALLS)