mirror_zfs/config/kernel-copy-from-user-inatomic.m4
Damian Szuberski 849c14e048
PPC get_user workaround
Linux 5.12 PPC 5.12 get_user() and __copy_from_user_inatomic()
inline helpers very indirectly include a reference to the GPL'd
array mmu_feature_keys[] and fails to build. Workaround this by
using copy_from_user() and throwing EFAULT for any calls to
__copy_from_user_inatomic(). This is a workaround until a fix
for Linux commit 7613f5a66becfd0e43a0f34de8518695888f5458
"powerpc/64s/kuap: Use mmu_has_feature()" is fully addressed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Authored-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #11958
Closes #12590
Closes #13367
2022-04-26 10:52:40 -07:00

27 lines
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dnl #
dnl # On certain architectures `__copy_from_user_inatomic`
dnl # is a GPL exported variable and cannot be used by OpenZFS.
dnl #
dnl #
dnl # Checking if `__copy_from_user_inatomic` is available.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_SRC___COPY_FROM_USER_INATOMIC], [
ZFS_LINUX_TEST_SRC([__copy_from_user_inatomic], [
#include <linux/uaccess.h>
], [
int result __attribute__ ((unused)) = __copy_from_user_inatomic(NULL, NULL, 0);
], [], [ZFS_META_LICENSE])
])
AC_DEFUN([ZFS_AC_KERNEL___COPY_FROM_USER_INATOMIC], [
AC_MSG_CHECKING([whether __copy_from_user_inatomic is available])
ZFS_LINUX_TEST_RESULT([__copy_from_user_inatomic_license], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE___COPY_FROM_USER_INATOMIC, 1,
[__copy_from_user_inatomic is available])
], [
AC_MSG_RESULT(no)
])
])