ExecutableAllocator.h [plain text]
#ifndef ExecutableAllocator_h
#define ExecutableAllocator_h
#include <stddef.h> // for ptrdiff_t
#include <limits>
#include <wtf/Assertions.h>
#include <wtf/MetaAllocatorHandle.h>
#include <wtf/PageAllocation.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/UnusedParam.h>
#include <wtf/Vector.h>
#if OS(IOS)
#include <libkern/OSCacheControl.h>
#endif
#if OS(IOS) || OS(QNX)
#include <sys/mman.h>
#endif
#if CPU(MIPS) && OS(LINUX)
#include <sys/cachectl.h>
#endif
#if CPU(SH4) && OS(LINUX)
#include <asm/cachectl.h>
#include <asm/unistd.h>
#include <sys/syscall.h>
#include <unistd.h>
#endif
#if OS(WINCE)
#define CACHE_SYNC_ALL 0x07F
extern "C" __declspec(dllimport) void CacheRangeFlush(LPVOID pAddr, DWORD dwLength, DWORD dwFlags);
#endif
#define JIT_ALLOCATOR_LARGE_ALLOC_SIZE (pageSize() * 4)
#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
#define PROTECTION_FLAGS_RW (PROT_READ | PROT_WRITE)
#define PROTECTION_FLAGS_RX (PROT_READ | PROT_EXEC)
#define EXECUTABLE_POOL_WRITABLE false
#else
#define EXECUTABLE_POOL_WRITABLE true
#endif
namespace JSC {
class JSGlobalData;
void releaseExecutableMemory(JSGlobalData&);
inline size_t roundUpAllocationSize(size_t request, size_t granularity)
{
if ((std::numeric_limits<size_t>::max() - granularity) <= request)
CRASH();
size_t size = request + (granularity - 1);
size = size & ~(granularity - 1);
ASSERT(size >= request);
return size;
}
}
#if ENABLE(JIT) && ENABLE(ASSEMBLER)
namespace JSC {
typedef WTF::MetaAllocatorHandle ExecutableMemoryHandle;
class ExecutableAllocator {
enum ProtectionSetting { Writable, Executable };
public:
ExecutableAllocator(JSGlobalData&);
static void initializeAllocator();
bool isValid() const;
static bool underMemoryPressure();
#if ENABLE(META_ALLOCATOR_PROFILE)
static void dumpProfile();
#else
static void dumpProfile() { }
#endif
PassRefPtr<ExecutableMemoryHandle> allocate(JSGlobalData&, size_t sizeInBytes);
#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
static void makeWritable(void* start, size_t size)
{
reprotectRegion(start, size, Writable);
}
static void makeExecutable(void* start, size_t size)
{
reprotectRegion(start, size, Executable);
}
#else
static void makeWritable(void*, size_t) {}
static void makeExecutable(void*, size_t) {}
#endif
#if CPU(X86) || CPU(X86_64)
static void cacheFlush(void*, size_t)
{
}
#elif CPU(MIPS)
static void cacheFlush(void* code, size_t size)
{
#if GCC_VERSION_AT_LEAST(4, 3, 0)
#if WTF_MIPS_ISA_REV(2) && !GCC_VERSION_AT_LEAST(4, 4, 3)
int lineSize;
asm("rdhwr %0, $1" : "=r" (lineSize));
intptr_t start = reinterpret_cast<intptr_t>(code) & (-lineSize);
intptr_t end = ((reinterpret_cast<intptr_t>(code) + size - 1) & (-lineSize)) - 1;
__builtin___clear_cache(reinterpret_cast<char*>(start), reinterpret_cast<char*>(end));
#else
intptr_t end = reinterpret_cast<intptr_t>(code) + size;
__builtin___clear_cache(reinterpret_cast<char*>(code), reinterpret_cast<char*>(end));
#endif
#else
_flush_cache(reinterpret_cast<char*>(code), size, BCACHE);
#endif
}
#elif CPU(ARM_THUMB2) && OS(IOS)
static void cacheFlush(void* code, size_t size)
{
sys_cache_control(kCacheFunctionPrepareForExecution, code, size);
}
#elif CPU(ARM_THUMB2) && OS(LINUX)
static void cacheFlush(void* code, size_t size)
{
asm volatile (
"push {r7}\n"
"mov r0, %0\n"
"mov r1, %1\n"
"movw r7, #0x2\n"
"movt r7, #0xf\n"
"movs r2, #0x0\n"
"svc 0x0\n"
"pop {r7}\n"
:
: "r" (code), "r" (reinterpret_cast<char*>(code) + size)
: "r0", "r1", "r2");
}
#elif CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(RVCT)
static __asm void cacheFlush(void* code, size_t size);
#elif CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(GCC)
static void cacheFlush(void* code, size_t size)
{
asm volatile (
"push {r7}\n"
"mov r0, %0\n"
"mov r1, %1\n"
"mov r7, #0xf0000\n"
"add r7, r7, #0x2\n"
"mov r2, #0x0\n"
"svc 0x0\n"
"pop {r7}\n"
:
: "r" (code), "r" (reinterpret_cast<char*>(code) + size)
: "r0", "r1", "r2");
}
#elif OS(WINCE)
static void cacheFlush(void* code, size_t size)
{
CacheRangeFlush(code, size, CACHE_SYNC_ALL);
}
#elif CPU(SH4) && OS(LINUX)
static void cacheFlush(void* code, size_t size)
{
#ifdef CACHEFLUSH_D_L2
syscall(__NR_cacheflush, reinterpret_cast<unsigned>(code), size, CACHEFLUSH_D_WB | CACHEFLUSH_I | CACHEFLUSH_D_L2);
#else
syscall(__NR_cacheflush, reinterpret_cast<unsigned>(code), size, CACHEFLUSH_D_WB | CACHEFLUSH_I);
#endif
}
#elif OS(QNX)
static void cacheFlush(void* code, size_t size)
{
#if !ENABLE(ASSEMBLER_WX_EXCLUSIVE)
msync(code, size, MS_INVALIDATE_ICACHE);
#else
UNUSED_PARAM(code);
UNUSED_PARAM(size);
#endif
}
#else
#error "The cacheFlush support is missing on this platform."
#endif
static size_t committedByteCount();
private:
#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
static void reprotectRegion(void*, size_t, ProtectionSetting);
#endif
};
}
#endif // ENABLE(JIT) && ENABLE(ASSEMBLER)
#endif // !defined(ExecutableAllocator)