KEYS: Use the compat keyctl() syscall wrapper on Sparc64 for Sparc32 compat

Use the 32-bit compat keyctl() syscall wrapper on Sparc64 for Sparc32 binary
compatibility.

Without this, keyctl(KEYCTL_INSTANTIATE_IOV) is liable to malfunction as it
uses an iovec array read from userspace - though the kernel should survive this
as it checks pointers and sizes anyway.

I think all the other keyctl() function should just work, provided (a) the top
32-bits of each 64-bit argument register are cleared prior to invoking the
syscall routine, and the 32-bit address space is right at the 0-end of the
64-bit address space.  Most of the arguments are 32-bit anyway, and so for
those clearing is not required.

Signed-off-by: David Howells <dhowells@redhat.com
cc: "David S. Miller" <davem@davemloft.net>
cc: sparclinux@vger.kernel.org
cc: stable@vger.kernel.org

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 6c0683d3fcba..76c7ccfb1ebe 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -584,6 +584,9 @@ config SYSVIPC_COMPAT
         depends on COMPAT && SYSVIPC
         default y
 
+config KEYS_COMPAT
+        def_bool y if COMPAT && KEYS
+
 endmenu
 
 source "net/Kconfig"