x86/entry/64: Add __SYSCALL_COMMON()

Add a __SYSCALL_COMMON() macro to the syscall table, which simplifies syscalltbl.sh.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200313195144.164260-12-brgerst@gmail.com

arch/x86/entry/syscall_64.c

@@ -9,6 +9,7 @@
 #include <asm/syscall.h>
 
 #define __SYSCALL_X32(nr, sym)
+#define __SYSCALL_COMMON(nr, sym) __SYSCALL_64(nr, sym)
 
 #define __SYSCALL_64(nr, sym) extern asmlinkage long sym(const struct pt_regs *);
 #include <asm/syscalls_64.h>

arch/x86/entry/syscall_x32.c

@@ -11,10 +11,13 @@
 #define __SYSCALL_64(nr, sym)
 
 #define __SYSCALL_X32(nr, sym) extern asmlinkage long sym(const struct pt_regs *);
+#define __SYSCALL_COMMON(nr, sym) extern asmlinkage long sym(const struct pt_regs *);
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_X32
+#undef __SYSCALL_COMMON
 
 #define __SYSCALL_X32(nr, sym) [nr] = sym,
+#define __SYSCALL_COMMON(nr, sym) [nr] = sym,
 
 asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_x32_syscall_max+1] = {
 	/*

arch/x86/entry/syscalls/syscalltbl.sh

@@ -25,7 +25,7 @@ emit() {
     fi
 
     # For CONFIG_UML, we need to strip the __x64_sys prefix
-    if [ "$abi" = "64" -a "${entry}" != "${entry#__x64_sys}" ]; then
+    if [ "${entry}" != "${entry#__x64_sys}" ]; then
 	    umlentry="sys${entry#__x64_sys}"
     fi
 
@@ -53,24 +53,6 @@ emit() {
 grep '^[0-9]' "$in" | sort -n | (
     while read nr abi name entry compat; do
 	abi=`echo "$abi" | tr '[a-z]' '[A-Z]'`
-	if [ "$abi" = "COMMON" -o "$abi" = "64" ]; then
-	    emit 64 "$nr" "$entry" "$compat"
-	    if [ "$abi" = "COMMON" ]; then
-		# COMMON means that this syscall exists in the same form for
-		# 64-bit and X32.
-		echo "#ifdef CONFIG_X86_X32_ABI"
-		emit X32 "$nr" "$entry" "$compat"
-		echo "#endif"
-	    fi
-	elif [ "$abi" = "X32" ]; then
-	    echo "#ifdef CONFIG_X86_X32_ABI"
-	    emit X32 "$nr" "$entry" "$compat"
-	    echo "#endif"
-	elif [ "$abi" = "I386" ]; then
-	    emit "$abi" "$nr" "$entry" "$compat"
-	else
-	    echo "Unknown abi $abi" >&2
-	    exit 1
-	fi
+	emit "$abi" "$nr" "$entry" "$compat"
     done
 ) > "$out"

arch/x86/um/sys_call_table_64.c

@@ -36,6 +36,9 @@
 #define stub_execveat sys_execveat
 #define stub_rt_sigreturn sys_rt_sigreturn
 
+#define __SYSCALL_X32(nr, sym)
+#define __SYSCALL_COMMON(nr, sym) __SYSCALL_64(nr, sym)
+
 #define __SYSCALL_64(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
 #include <asm/syscalls_64.h>