x86/syscalls: Disallow compat entries for all types of 64-bit syscalls

A "compat" entry in the syscall tables means to use a different entry on
32-bit and 64-bit builds.

This only makes sense for syscalls that exist in the first place in 32-bit
builds, so disallow it for anything other than i386.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/4b7565954c5a06530ac01d98cb1592538fd8ae51.1562185330.git.luto@kernel.org

diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index 94fcd1951acaae51a3391d061e429f866469baae..53c8c1a9adf94605b766260e00d3b46218896e40 100644 (file)
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -27,8 +27,8 @@ emit() {
     compat="$4"
     umlentry=""
 
-    if [ "$abi" = "64" -a -n "$compat" ]; then
-       echo "a compat entry for a 64-bit syscall makes no sense" >&2
+    if [ "$abi" != "I386" -a -n "$compat" ]; then
+       echo "a compat entry ($abi: $compat) for a 64-bit syscall makes no sense" >&2
        exit 1
     fi