ARM64: Add support for ARM64e pointer authentication codes (PAC).

Contributed by Peter Cawley. #559

1 files changed, 9 insertions, 3 deletions

diff --git a/src/lj_emit_arm64.h b/src/lj_emit_arm64.h
index fcc9c1d8..65463a5e 100644
--- a/src/lj_emit_arm64.h
+++ b/src/lj_emit_arm64.h
@@ -348,16 +348,22 @@ static void emit_cnb(ASMState *as, A64Ins ai, Reg r, MCode *target)
 
 #define emit_jmp(as, target)    emit_branch(as, A64I_B, (target))
 
-static void emit_call(ASMState *as, void *target)
+static void emit_call(ASMState *as, ASMFunction target)
 {
   MCode *p = --as->mcp;
-  ptrdiff_t delta = (char *)target - (char *)p;
+#if LJ_ABI_PAUTH
+  char *targetp = ptrauth_auth_data((char *)target,
+                                    ptrauth_key_function_pointer, 0);
+#else
+  char *targetp = (char *)target;
+#endif
+  ptrdiff_t delta = targetp - (char *)p;
   if (A64F_S_OK(delta>>2, 26)) {
     *p = A64I_BL | A64F_S26(delta>>2);
   } else {  /* Target out of range: need indirect call. But don't use R0-R7. */
     Reg r = ra_allock(as, i64ptr(target),
                       RSET_RANGE(RID_X8, RID_MAX_GPR)-RSET_FIXED);
-    *p = A64I_BLR | A64F_N(r);
+    *p = A64I_BLR_AUTH | A64F_N(r);
   }
 }