config/kernel-zero_page.m4

   1 dnl #
   2 dnl # ZERO_PAGE() is an alias for emtpy_zero_page. On certain architectures
   3 dnl # this is a GPL exported variable.
   4 dnl #
   5
   6 dnl #
   7 dnl # Checking if ZERO_PAGE is exported GPL-only
   8 dnl #
   9 AC_DEFUN([ZFS_AC_KERNEL_SRC_ZERO_PAGE], [
  10         ZFS_LINUX_TEST_SRC([zero_page], [
  11                 #include <asm/pgtable.h>
  12         ], [
  13                 struct page *p __attribute__ ((unused));
  14                 p = ZERO_PAGE(0);
  15         ], [], [ZFS_META_LICENSE])
  16 ])
  17
  18 AC_DEFUN([ZFS_AC_KERNEL_ZERO_PAGE], [
  19         AC_MSG_CHECKING([whether ZERO_PAGE() is GPL-only])
  20         ZFS_LINUX_TEST_RESULT([zero_page_license], [
  21                 AC_MSG_RESULT(no)
  22         ], [
  23                 AC_MSG_RESULT(yes)
  24                 AC_DEFINE(HAVE_ZERO_PAGE_GPL_ONLY, 1,
  25                     [ZERO_PAGE() is GPL-only])
  26         ])
  27 ])