JavaScriptCore-584.tar.gz

[apple/javascriptcore.git] / jit / ExecutableAllocatorPosix.cpp

diff --git a/jit/ExecutableAllocatorPosix.cpp b/jit/ExecutableAllocatorPosix.cpp
index 21955d7829dfc3eb3dcdf1c0f39fd8928add7f60..06375adb537f2ed0713118e58dae761772de9676 100644 (file)
--- a/jit/ExecutableAllocatorPosix.cpp
+++ b/jit/ExecutableAllocatorPosix.cpp
@@ -27,13 +27,16 @@
 
 #include "ExecutableAllocator.h"
 
-#if ENABLE(ASSEMBLER)
+#if ENABLE(ASSEMBLER) && OS(UNIX) && !OS(SYMBIAN)
 
 #include <sys/mman.h>
 #include <unistd.h>
+#include <wtf/VMTags.h>
 
 namespace JSC {
 
+#if !(OS(DARWIN) && CPU(X86_64))
+
 void ExecutableAllocator::intializePageSize()
 {
     ExecutableAllocator::pageSize = getpagesize();
@@ -41,16 +44,42 @@ void ExecutableAllocator::intializePageSize()
 
 ExecutablePool::Allocation ExecutablePool::systemAlloc(size_t n)
 {
-    ExecutablePool::Allocation alloc = {reinterpret_cast<char*>(mmap(NULL, n, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0)), n};
+    void* allocation = mmap(NULL, n, INITIAL_PROTECTION_FLAGS, MAP_PRIVATE | MAP_ANON, VM_TAG_FOR_EXECUTABLEALLOCATOR_MEMORY, 0);
+    if (allocation == MAP_FAILED)
+        CRASH();
+    ExecutablePool::Allocation alloc = { reinterpret_cast<char*>(allocation), n };
     return alloc;
 }
 
-void ExecutablePool::systemRelease(const ExecutablePool::Allocation& alloc) 
+void ExecutablePool::systemRelease(const ExecutablePool::Allocation& alloc)
 { 
     int result = munmap(alloc.pages, alloc.size);
     ASSERT_UNUSED(result, !result);
 }
 
+#endif // !(OS(DARWIN) && CPU(X86_64))
+
+#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
+void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSeting setting)
+{
+    if (!pageSize)
+        intializePageSize();
+
+    // Calculate the start of the page containing this region,
+    // and account for this extra memory within size.
+    intptr_t startPtr = reinterpret_cast<intptr_t>(start);
+    intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
+    void* pageStart = reinterpret_cast<void*>(pageStartPtr);
+    size += (startPtr - pageStartPtr);
+
+    // Round size up
+    size += (pageSize - 1);
+    size &= ~(pageSize - 1);
+
+    mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
+}
+#endif
+
 }
 
 #endif // HAVE(ASSEMBLER)