ARM64: Fix exit stub patching.

Contributed by Javier Guerra Giraldez.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/lj_target_arm64.h b/src/lj_target_arm64.h
index 520023ae..a207a2ba 100644
--- a/src/lj_target_arm64.h
+++ b/src/lj_target_arm64.h
@@ -132,9 +132,9 @@ static LJ_AINLINE uint32_t *exitstub_trace_addr_(uint32_t *p, uint32_t exitno)
 #define A64F_IMMR(x)    ((x) << 16)
 #define A64F_U16(x)     ((x) << 5)
 #define A64F_U12(x)     ((x) << 10)
-#define A64F_S26(x)     (x)
+#define A64F_S26(x)     (((uint32_t)(x) & 0x03ffffffu))
 #define A64F_S19(x)     (((uint32_t)(x) & 0x7ffffu) << 5)
-#define A64F_S14(x)     ((x) << 5)
+#define A64F_S14(x)     (((uint32_t)(x) & 0x3fffu) << 5)
 #define A64F_S9(x)      ((x) << 12)
 #define A64F_BIT(x)     ((x) << 19)
 #define A64F_SH(sh, x)  (((sh) << 22) | ((x) << 10))
@@ -145,6 +145,9 @@ static LJ_AINLINE uint32_t *exitstub_trace_addr_(uint32_t *p, uint32_t exitno)
 #define A64F_LSL16(x)   (((x) / 16) << 21)
 #define A64F_BSH(sh)    ((sh) << 10)
 
+/* Check for valid field range. */
+#define A64F_S_OK(x, b) ((((x) + (1 << (b-1))) >> (b)) == 0)
+
 typedef enum A64Ins {
   A64I_S = 0x20000000,
   A64I_X = 0x80000000,