From f88bf8bbff9c897370f4e9327373a60d49588982 Mon Sep 17 00:00:00 2001
From: Sacha <xsacha@gmail.com>
Date: Thu, 14 Mar 2013 14:40:01 +1000
Subject: [PATCH] Attempt at fixing JIT on iOS. Can only have PROT_WRITE or
 PROT_EXEC enabled. So toggle between them as needed.

---
 Common/ArmEmitter.cpp    |  3 +--
 Common/ArmEmitter.h      |  6 +++++-
 Common/MemoryUtil.cpp    |  2 +-
 Core/MIPS/ARM/ArmJit.cpp | 13 +++++++++++++
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/Common/ArmEmitter.cpp b/Common/ArmEmitter.cpp
index e2f55ccb74..00cf93de3f 100644
--- a/Common/ArmEmitter.cpp
+++ b/Common/ArmEmitter.cpp
@@ -236,8 +236,7 @@ void ARMXEmitter::FlushIcacheSection(u8 *start, u8 *end)
 #elif defined(BLACKBERRY)
 	msync(start, end - start, MS_SYNC | MS_INVALIDATE_ICACHE);
 #elif defined(IOS)
-	if (start != NULL)
-		sys_cache_control(kCacheFunctionPrepareForExecution, start, end - start);
+	sys_cache_control(kCacheFunctionPrepareForExecution, start, end - start);
 #elif !defined(_WIN32)
 	__builtin___clear_cache(start, end);
 #endif
diff --git a/Common/ArmEmitter.h b/Common/ArmEmitter.h
index 9fbe8c5d4d..a31e1753a2 100644
--- a/Common/ArmEmitter.h
+++ b/Common/ArmEmitter.h
@@ -611,7 +611,11 @@ public:
 	// Start over if you need to change the code (call FreeCodeSpace(), AllocCodeSpace()).
 	void WriteProtect()
 	{
-		WriteProtectMemory(region, region_size, true);		
+		WriteProtectMemory(region, region_size, true);
+	}
+	void UnWriteProtect()
+	{
+		UnWriteProtectMemory(region, region_size, false);
 	}
 
 	void ResetCodePtr()
diff --git a/Common/MemoryUtil.cpp b/Common/MemoryUtil.cpp
index a7119b307c..d474ed633e 100644
--- a/Common/MemoryUtil.cpp
+++ b/Common/MemoryUtil.cpp
@@ -86,7 +86,7 @@ void* AllocateExecutableMemory(size_t size, bool low)
 	if (low && (!map_hint))
 		map_hint = (char*)round_page(512*1024*1024); /* 0.5 GB rounded up to the next page */
 #endif
-	void* ptr = mmap(map_hint, size, PROT_READ | PROT_WRITE | PROT_EXEC,
+	void* ptr = mmap(map_hint, size, PROT_READ | PROT_WRITE	| PROT_EXEC,
 		MAP_ANON | MAP_PRIVATE
 #if defined(__x86_64__) && defined(MAP_32BIT)
 		| (low ? MAP_32BIT : 0)
diff --git a/Core/MIPS/ARM/ArmJit.cpp b/Core/MIPS/ARM/ArmJit.cpp
index f2e57473b9..63919f8906 100644
--- a/Core/MIPS/ARM/ArmJit.cpp
+++ b/Core/MIPS/ARM/ArmJit.cpp
@@ -62,7 +62,13 @@ Jit::Jit(MIPSState *mips) : blocks(mips), gpr(mips), fpr(mips),	 mips_(mips)
 	gpr.SetEmitter(this);
 	fpr.SetEmitter(this);
 	AllocCodeSpace(1024 * 1024 * 16);  // 32MB is the absolute max because that's what an ARM branch instruction can reach, backwards and forwards.
+#ifdef IOS
+	UnWriteProtect();
+#endif
 	GenerateFixedCode();
+#ifdef IOS
+	WriteProtect();
+#endif
 
 	js.startDefaultPrefix = true;
 }
@@ -201,6 +207,10 @@ const u8 *Jit::DoJit(u32 em_address, ArmJitBlock *b)
 	js.inDelaySlot = false;
 	js.PrefixStart();
 
+#ifdef IOS
+	UnWriteProtect();
+#endif
+
 	// We add a check before the block, used when entering from a linked block.
 	b->checkedEntry = GetCodePtr();
 	// Downcount flag check. The last block decremented downcounter, and the flag should still be available.
@@ -255,6 +265,9 @@ const u8 *Jit::DoJit(u32 em_address, ArmJitBlock *b)
 		}
 	}
 #endif
+#ifdef IOS
+	WriteProtect();
+#endif
 
 	b->codeSize = GetCodePtr() - b->normalEntry;