kmemcheck: move 64-bit ifdef out of kmemcheck_opcode_decode()

This patch moves the CONFIG_X86_64 ifdef out of kmemcheck_opcode_decode() by
introducing a version of the function that always returns false for
CONFIG_X86_32.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/arch/x86/mm/kmemcheck/opcode.c b/arch/x86/mm/kmemcheck/opcode.c
index a4100b6e783a..63c19e27aa6f 100644
--- a/arch/x86/mm/kmemcheck/opcode.c
+++ b/arch/x86/mm/kmemcheck/opcode.c
@@ -16,10 +16,17 @@ static bool opcode_is_prefix(uint8_t b)
                 || b == 0x67;
 }
 
+#ifdef CONFIG_X86_64
 static bool opcode_is_rex_prefix(uint8_t b)
 {
         return (b & 0xf0) == 0x40;
 }
+#else
+static bool opcode_is_rex_prefix(uint8_t b)
+{
+        return false;
+}
+#endif
 
 #define REX_W (1 << 3)
 
@@ -40,7 +47,6 @@ void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size)
                         operand_size_override = 2;
         }
 
-#ifdef CONFIG_X86_64
         /* REX prefix */
         if (opcode_is_rex_prefix(*op)) {
                 uint8_t rex = *op;
@@ -72,7 +78,6 @@ void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size)
                         return;
                 }
         }
-#endif
 
         /* escape opcode */
         if (*op == 0x0f) {