From b252636dc38ced4288cbabbea4ff675f69e393db Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Sat, 6 Feb 2021 22:15:02 +0000
Subject: [PATCH] a32_unicorn: Halt when PC leaves code_mem

---
 tests/A32/fuzz_arm.cpp            | 17 +++--------------
 tests/A32/testenv.h               | 11 +++++++----
 tests/unicorn_emu/a32_unicorn.cpp |  3 +++
 3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/tests/A32/fuzz_arm.cpp b/tests/A32/fuzz_arm.cpp
index 2cd9b47e..41b37733 100644
--- a/tests/A32/fuzz_arm.cpp
+++ b/tests/A32/fuzz_arm.cpp
@@ -215,6 +215,8 @@ static void RunTestInstance(Dynarmic::A32::Jit& jit,
 
     jit_env.code_mem.resize(code_mem_size);
     uni_env.code_mem.resize(code_mem_size);
+    std::fill(jit_env.code_mem.begin(), jit_env.code_mem.end(), TestEnv::infinite_loop);
+    std::fill(uni_env.code_mem.begin(), uni_env.code_mem.end(), TestEnv::infinite_loop);
 
     std::copy(instructions.begin(), instructions.end(), jit_env.code_mem.begin() + num_words);
     std::copy(instructions.begin(), instructions.end(), uni_env.code_mem.begin() + num_words);
@@ -240,20 +242,7 @@ static void RunTestInstance(Dynarmic::A32::Jit& jit,
     jit_env.ticks_left = ticks_left;
     jit.Run();
 
-    uni_env.ticks_left = [&]{
-        if constexpr (std::is_same_v<TestEnv, ThumbTestEnv>) {
-            // Unicorn counts thumb instructions weirdly:
-            // A 32-bit thumb instruction counts as two.
-            // Except for branch instructions which count as one???
-            if (instructions.size() <= 1)
-                return ticks_left;
-            if ((instructions[instructions.size() - 2] & 0xF800) <= 0xE800)
-                return instructions.size();
-            return instructions.size() - 1;
-        } else {
-            return ticks_left;
-        }
-    }();
+    uni_env.ticks_left = instructions.size(); // Unicorn counts thumb instructions weirdly.
     uni.Run();
 
     SCOPE_FAIL {
diff --git a/tests/A32/testenv.h b/tests/A32/testenv.h
index 75e15841..95780222 100644
--- a/tests/A32/testenv.h
+++ b/tests/A32/testenv.h
@@ -37,18 +37,21 @@ public:
         } while (code_mem.size() % 2 != 0);
     }
 
+    bool IsInCodeMem(u32 vaddr) const {
+        return vaddr < sizeof(InstructionType) * code_mem.size();
+    }
+
     std::uint32_t MemoryReadCode(u32 vaddr) override {
-        const size_t index = vaddr / sizeof(InstructionType);
-        if (index < code_mem.size()) {
+        if (IsInCodeMem(vaddr)) {
             u32 value;
-            std::memcpy(&value, &code_mem[index], sizeof(u32));
+            std::memcpy(&value, &code_mem[vaddr / sizeof(InstructionType)], sizeof(u32));
             return value;
         }
         return infinite_loop_u32; // B .
     }
 
     std::uint8_t MemoryRead8(u32 vaddr) override {
-        if (vaddr < sizeof(InstructionType) * code_mem.size()) {
+        if (IsInCodeMem(vaddr)) {
             return reinterpret_cast<u8*>(code_mem.data())[vaddr];
         }
         if (auto iter = modified_memory.find(vaddr); iter != modified_memory.end()) {
diff --git a/tests/unicorn_emu/a32_unicorn.cpp b/tests/unicorn_emu/a32_unicorn.cpp
index f7501913..16052e4c 100644
--- a/tests/unicorn_emu/a32_unicorn.cpp
+++ b/tests/unicorn_emu/a32_unicorn.cpp
@@ -44,6 +44,9 @@ void A32Unicorn<TestEnvironment>::Run() {
     constexpr u64 pc_mask = std::is_same_v<TestEnvironment, ArmTestEnv> ? 0 : 1;
     while (testenv.ticks_left > 0) {
         const u32 pc = GetPC() | pc_mask;
+        if (!testenv.IsInCodeMem(pc)) {
+            return;
+        }
         if (auto cerr_ = uc_emu_start(uc, pc, END_ADDRESS, 0, 1)) {
             ASSERT_MSG(false, "uc_emu_start failed @ {:08x} (code = {:08x}) with error {} ({})", pc, testenv.MemoryReadCode(pc), cerr_, uc_strerror(cerr_));
         }