S390: KEYS: Enable the compat keyctl wrapper on s390x

commit 1d057720609ed052a6371fe1d53300e5e6328e94 upstream.

Enable the compat keyctl wrapper on s390x so that 32-bit s390 userspace can
call the keyctl() syscall.

There's an s390x assembly wrapper that truncates all the register values to
32-bits and this then calls compat_sys_keyctl() - but the latter only exists if
CONFIG_KEYS_COMPAT is enabled, and the s390 Kconfig doesn't enable it.

Without this patch, 32-bit calls to the keyctl() syscall are given an ENOSYS
error:

	[root@devel4 ~]# keyctl show
	Session Keyring
	-3: key inaccessible (Function not implemented)

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: dan@danny.cz
Cc: Carsten Otte <cotte@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index c03fef7a9c2220c45ca1584ad8f65191bb5c9e76..9b922b12e9f089eb66b4f8f2caa3ff04ef276342 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -228,6 +228,9 @@ config COMPAT
 config SYSVIPC_COMPAT
        def_bool y if COMPAT && SYSVIPC
 
+config KEYS_COMPAT
+       def_bool y if COMPAT && KEYS
+
 config AUDIT_ARCH
        def_bool y