libretro/ppsspp
1
0
Fork 0
mirror of https://github.com/libretro/ppsspp.git synced 2024-12-04 23:16:41 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Memory function cleanups. Better simulation of RW exclusive mode on Windows (if desired)

Browse Source
This commit is contained in:
Henrik Rydgård 2017-01-26 09:49:26 +01:00
parent 69b35a35be
commit 1503f00885
2 changed files with 18 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Common/CodeBlock.h
View File

@ -51,12 +51,9 @@ public:
// Call this before you generate any code.
void AllocCodeSpace(int size) {
region_size = size;
// The protection will be set to RW if PlatformIsWXExclusive.
region = (u8*)AllocateExecutableMemory(region_size);
T::SetCodePointer(region);
// On W^X platforms, we start with writable but not executable pages.
if (PlatformIsWXExclusive()) {
ProtectMemoryPages(region, region_size, MEM_PROT_READ | MEM_PROT_WRITE);
}
}
// Always clear code space with breakpoints, so that if someone accidentally executes
@ -71,7 +68,8 @@ public:
ResetCodePtr();
}
// BeginWrite/EndWrite assume that we keep appending. If you don't specify a size and we encounter later executable block, we're screwed.
// BeginWrite/EndWrite assume that we keep appending.
// If you don't specify a size and we later encounter an executable non-writable block, we're screwed.
// These CANNOT be nested. We rely on the memory protection starting at READ|WRITE after start and reset.
void BeginWrite(size_t sizeEstimate = 1) {
#ifdef _DEBUG

23
Common/MemoryUtil.cpp
View File

@ -50,7 +50,7 @@ static SYSTEM_INFO sys_info;
#ifdef _WIN32
// Win32 flags are odd...
uint32_t ConvertProtFlagsWin32(uint32_t flags) {
static uint32_t ConvertProtFlagsWin32(uint32_t flags) {
uint32_t protect = 0;
switch (flags) {
case 0: protect = PAGE_NOACCESS; break;
@ -67,7 +67,7 @@ uint32_t ConvertProtFlagsWin32(uint32_t flags) {
#else
uint32_t ConvertProtFlagsUnix(uint32_t flags) {
static uint32_t ConvertProtFlagsUnix(uint32_t flags) {
uint32_t protect = 0;
if (flags & MEM_PROT_READ)
protect |= PROT_READ;
@ -117,6 +117,9 @@ static void *SearchForFreeMem(size_t size) {
void *AllocateExecutableMemory(size_t size) {
#if defined(_WIN32)
void *ptr;
DWORD prot = PAGE_EXECUTE_READWRITE;
if (PlatformIsWXExclusive())
prot = PAGE_READWRITE;
#if defined(_M_X64)
if ((uintptr_t)&hint_location > 0xFFFFFFFFULL) {
if (sys_info.dwPageSize == 0)
@ -131,14 +134,16 @@ void *AllocateExecutableMemory(size_t size) {
ptr = SearchForFreeMem(aligned_size);
}
if (ptr) {
ptr = VirtualAlloc(ptr, aligned_size, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
ptr = VirtualAlloc(ptr, aligned_size, MEM_RESERVE | MEM_COMMIT, prot);
} else {
ERROR_LOG(COMMON, "Unable to find nearby executable memory for jit");
}
}
else
#endif
ptr = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
{
ptr = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, prot);
}
#else
static char *map_hint = 0;
#if defined(_M_X64)
@ -192,7 +197,6 @@ void *AllocateExecutableMemory(size_t size) {
}
}
#endif
return ptr;
}
@ -205,7 +209,7 @@ void *AllocateMemoryPages(size_t size, uint32_t memProtFlags) {
PanicAlert("Failed to allocate raw memory");
#else
uint32_t protect = ConvertProtFlagsUnix(memProtFlags);
void* ptr = mmap(0, size, protect, MAP_ANON | MAP_PRIVATE, -1, 0);
void *ptr = mmap(0, size, protect, MAP_ANON | MAP_PRIVATE, -1, 0);
if (ptr == MAP_FAILED) {
ERROR_LOG(MEMMAP, "Failed to allocate memory pages: errno=%d", errno);
return nullptr;
@ -274,11 +278,14 @@ bool PlatformIsWXExclusive() {
}
bool ProtectMemoryPages(const void* ptr, size_t size, uint32_t memProtFlags) {
VERBOSE_LOG(JIT, "ProtectMemoryPages: %p (%d) : r%d w%d x%d", ptr, (int)size, (memProtFlags & MEM_PROT_READ) != 0, (memProtFlags & MEM_PROT_WRITE) != 0, (memProtFlags & MEM_PROT_EXEC) != 0);
VERBOSE_LOG(JIT, "ProtectMemoryPages: %p (%d) : r%d w%d x%d", ptr, (int)size,
(memProtFlags & MEM_PROT_READ) != 0, (memProtFlags & MEM_PROT_WRITE) != 0, (memProtFlags & MEM_PROT_EXEC) != 0);
if (PlatformIsWXExclusive()) {
if ((memProtFlags & (MEM_PROT_WRITE | MEM_PROT_EXEC)) == (MEM_PROT_WRITE | MEM_PROT_EXEC))
if ((memProtFlags & (MEM_PROT_WRITE | MEM_PROT_EXEC)) == (MEM_PROT_WRITE | MEM_PROT_EXEC)) {
ERROR_LOG(MEMMAP, "Bad memory protection %d!", memProtFlags);
PanicAlert("Bad memory protect : W^X is in effect, can't both write and exec");
}
}
// Note - VirtualProtect will affect the full pages containing the requested range.
// mprotect does not seem to, at least not on Android unless I made a mistake somewhere, so we manually round.