1 files changed, 19 insertions, 0 deletions
diff --git a/lib/arm64/jump-patch.h b/lib/arm64/jump-patch.h
new file mode 100644
index 0000000..f0f149f
--- /dev/null
+++ b/lib/arm64/jump-patch.h
@@ -0,0 +1,19 @@
+#pragma once
+#include "arm64/assemble.h"
+#define MAX_JUMP_PATCH_SIZE 12
+#define MAX_REWRITTEN_SIZE (7 * 2 * 4) /* also conservative */
+static inline int jump_patch_size(uintptr_t pc, uintptr_t dpc,
+                                  struct arch_dis_ctx arch) {
+    intptr_t diff = (dpc & ~0xfff) - (pc & ~0xfff);
+    if (!(diff >= -0x100000000 && diff < 0x100000000))
+        return -1;
+    else if (pc & 0xfff)
+        return 8;
+    else
+        return 12;
+}
+
+static inline void make_jump_patch(void **codep, uintptr_t pc, uintptr_t dpc,
+                                   struct arch_dis_ctx arch) {
+    ADRP_ADD(codep, 12 /* XXX */, pc, dpc);
+}