Update.

1999-05-26  Ulrich Drepper  <drepper@cygnus.com>

	* config.h.in: Add __LINUX_KERNEL_VERSION.
	* configure.in: Recognize --enable-kernel.
	* sysdeps/unix/sysv/linux/configure.in: Check for correct kernel
	headers if --enable-kernel is given and set __LINUX_KERNEL_VERSION
	appropriately.
	* sysdeps/unix/sysv/linux/init-first.c: If minimal kernel version is
	given perform runtime test.

	* sysdeps/unix/sysv/linux/kernel-features.h: New file.
	* sysdeps/unix/sysv/linux/getcwd.c: Elide compatibility code if
	minimal supported kernel is known to have the feature.
	* sysdeps/unix/sysv/linux/poll.c: Likewise.
	* sysdeps/unix/sysv/linux/pread.c: Likewise.
	* sysdeps/unix/sysv/linux/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/pwrite.c: Likewise.
	* sysdeps/unix/sysv/linux/pwrite64.c: Likewise.
	* sysdeps/unix/sysv/linux/seteuid.c: Likewise.
	* sysdeps/unix/sysv/linux/sigaction.c: Likewise.
	* sysdeps/unix/sysv/linux/sigprocmask.c: Likewise.
	* sysdeps/unix/sysv/linux/sigsuspend.c: Likewise.
	* sysdeps/unix/sysv/linux/testrtsig.h: Likewise.
	* sysdeps/unix/sysv/linux/i386/chown.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/pread.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/pwrite.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/pwrite64.c: Likewise.

	* sysdeps/unix/sysv/linux/sysctl.c: Add __sysctl alias.

1 files changed, 31 insertions, 2 deletions

diff --git a/sysdeps/unix/sysv/linux/configure b/sysdeps/unix/sysv/linux/configure
index bf5e797d31..f5d994b1c7 100644
--- a/sysdeps/unix/sysv/linux/configure
+++ b/sysdeps/unix/sysv/linux/configure
@@ -13,7 +13,7 @@ if test -n "$sysheaders"; then
 fi
 echo $ac_n "checking installed Linux kernel header files""... $ac_c" 1>&6
 echo "configure:16: checking installed Linux kernel header files" >&5
-if eval "test \"`echo '$''{'libc_cv_linux2010'+set}'`\" = set"; then
+if eval "test \"\${libc_cv_linux2010+set}\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
@@ -49,6 +49,35 @@ 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." 1>&2; exit 1; }
 fi
+
+# If the user gave a minimal version number test whether the available
+# kernel headers are young enough.
+if test -n "$minimum_kernel"; then
+  echo $ac_n "checking for kernel header at least $minimum_kernel""... $ac_c" 1>&6
+echo "configure:58: checking for kernel header at least $minimum_kernel" >&5
+  decnum=`echo "$minimum_kernel.0.0.0" | sed 's/\([0-9]*\)\.\([0-9]*\)\.\(\([0-9]*\)\|\).*/(\1 * 65536 + \2 * 256 + \3)/'`;
+  cat > conftest.$ac_ext <<EOF
+#include <linux/version.h>
+int main() {
+#if LINUX_VERSION_CODE < $decnum
+eat flaming death
+#endif
+; return 0; }
+EOF
+  if { (eval echo configure:30: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+    cat >> confdefs.h <<EOF
+#define __LINUX_KERNEL_VERSION $decnum
+EOF
+
+    echo "$ac_t""ok" 1>&6
+  else
+    echo "$ac_t""too old!" 1>&6
+    { echo "configure: error: *** The available kernel headers are not at least as old as the requested
+*** compatible kernel version" 1>&2; exit 1; }
+  fi
+  rm -f conftest*
+fi
+
 if test -n "$sysheaders"; then
   CFLAGS=$OLD_CFLAGS
 fi
@@ -135,7 +164,7 @@ if test $host = $build; then
     ac_prefix=$ac_default_prefix
   fi
   echo $ac_n "checking for symlinks in ${ac_prefix}/include""... $ac_c" 1>&6
-echo "configure:131: checking for symlinks in ${ac_prefix}/include" >&5
+echo "configure:168: checking for symlinks in ${ac_prefix}/include" >&5
   ac_message=
   if test -L ${ac_prefix}/include/net; then
     ac_message="$ac_message