Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index d5252bc..b1bf317 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -10,10 +10,13 @@
 /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
 extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+#define __SYSCALL_X32(nr, sym, qual) __SYSCALL_64(nr, sym, qual)
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
+#undef __SYSCALL_X32
 
 #define __SYSCALL_64(nr, sym, qual) [nr] = sym,
+#define __SYSCALL_X32(nr, sym, qual)
 
 asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	/*
@@ -23,3 +26,25 @@
 	[0 ... __NR_syscall_max] = &sys_ni_syscall,
 #include <asm/syscalls_64.h>
 };
+
+#undef __SYSCALL_64
+#undef __SYSCALL_X32
+
+#ifdef CONFIG_X86_X32_ABI
+
+#define __SYSCALL_64(nr, sym, qual)
+#define __SYSCALL_X32(nr, sym, qual) [nr] = sym,
+
+asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_syscall_x32_max+1] = {
+	/*
+	 * Smells like a compiler bug -- it doesn't work
+	 * when the & below is removed.
+	 */
+	[0 ... __NR_syscall_x32_max] = &sys_ni_syscall,
+#include <asm/syscalls_64.h>
+};
+
+#undef __SYSCALL_64
+#undef __SYSCALL_X32
+
+#endif