From 1e451b386a871d2ac877cf613e36f8a89f7c98ba Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Sun, 4 Feb 2018 23:17:28 -0500
Subject: [PATCH] translate-a64: Backport fix for incorrect load/store
 exclusive unallocated checks

Backports commit e14f0eb12f920fd96b9f79d15cedd437648e8667 from qemu
---
 qemu/target-arm/translate-a64.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/qemu/target-arm/translate-a64.c b/qemu/target-arm/translate-a64.c
index 89eac7bf..043e2175 100644
--- a/qemu/target-arm/translate-a64.c
+++ b/qemu/target-arm/translate-a64.c
@@ -1783,9 +1783,6 @@ static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2,
  *  o2: 0 -> exclusive, 1 -> not
  *  o1: 0 -> single register, 1 -> register pair
  *  o0: 1 -> load-acquire/store-release, 0 -> not
- *
- *  o0 == 0 AND o2 == 1 is un-allocated
- *  o1 == 1 is un-allocated except for 32 and 64 bit sizes
  */
 static void disas_ldst_excl(DisasContext *s, uint32_t insn)
 {
@@ -1801,7 +1798,8 @@ static void disas_ldst_excl(DisasContext *s, uint32_t insn)
     int size = extract32(insn, 30, 2);
     TCGv_i64 tcg_addr;
 
-    if ((!is_excl && !is_lasr) ||
+    if ((!is_excl && !is_pair && !is_lasr) ||
+        (!is_excl && is_pair) ||
         (is_pair && size < 2)) {
         unallocated_encoding(s);
         return;
@@ -1830,15 +1828,6 @@ static void disas_ldst_excl(DisasContext *s, uint32_t insn)
         } else {
             do_gpr_ld(s, tcg_rt, tcg_addr, size, false, false);
         }
-        if (is_pair) {
-            TCGv_i64 tcg_rt2 = cpu_reg(s, rt);
-            tcg_gen_addi_i64(tcg_ctx, tcg_addr, tcg_addr, 1ULL << size);
-            if (is_store) {
-                do_gpr_st(s, tcg_rt2, tcg_addr, size);
-            } else {
-                do_gpr_ld(s, tcg_rt2, tcg_addr, size, false, false);
-            }
-        }
     }
 }