Memmap: Replace some GetPointer calls

These GetPointer calls could cause crashes, in part because the
callers didn't do null checks and in part because GetPointer
inherently is unsafe to use for accesses larger than 1 byte.
This commit is contained in:
JosJuice 2021-12-20 21:41:52 +01:00
parent 6dae4043cb
commit 5dd2ddb1df
2 changed files with 28 additions and 13 deletions

View File

@ -466,16 +466,22 @@ void Clear()
memset(m_pEXRAM, 0, GetExRamSize()); memset(m_pEXRAM, 0, GetExRamSize());
} }
static inline u8* GetPointerForRange(u32 address, size_t size) u8* GetPointerForRange(u32 address, size_t size)
{ {
// Make sure we don't have a range spanning 2 separate banks // Make sure we don't have a range spanning 2 separate banks
if (size >= GetExRamSizeReal()) if (size >= GetExRamSizeReal())
{
PanicAlertFmt("Oversized range in GetPointerForRange. {:x} bytes at {:#010x}", size, address);
return nullptr; return nullptr;
}
// Check that the beginning and end of the range are valid // Check that the beginning and end of the range are valid
u8* pointer = GetPointer(address); u8* pointer = GetPointer(address);
if (!pointer || !GetPointer(address + u32(size) - 1)) if (!pointer || !GetPointer(address + u32(size) - 1))
{
// A panic alert has already been raised by GetPointer
return nullptr; return nullptr;
}
return pointer; return pointer;
} }
@ -559,55 +565,63 @@ u8* GetPointer(u32 address)
u8 Read_U8(u32 address) u8 Read_U8(u32 address)
{ {
return *GetPointer(address); u8 value = 0;
CopyFromEmu(&value, address, sizeof(value));
return value;
} }
u16 Read_U16(u32 address) u16 Read_U16(u32 address)
{ {
return Common::swap16(GetPointer(address)); u16 value = 0;
CopyFromEmu(&value, address, sizeof(value));
return Common::swap16(value);
} }
u32 Read_U32(u32 address) u32 Read_U32(u32 address)
{ {
return Common::swap32(GetPointer(address)); u32 value = 0;
CopyFromEmu(&value, address, sizeof(value));
return Common::swap32(value);
} }
u64 Read_U64(u32 address) u64 Read_U64(u32 address)
{ {
return Common::swap64(GetPointer(address)); u64 value = 0;
CopyFromEmu(&value, address, sizeof(value));
return Common::swap64(value);
} }
void Write_U8(u8 value, u32 address) void Write_U8(u8 value, u32 address)
{ {
*GetPointer(address) = value; CopyToEmu(address, &value, sizeof(value));
} }
void Write_U16(u16 value, u32 address) void Write_U16(u16 value, u32 address)
{ {
u16 swapped_value = Common::swap16(value); u16 swapped_value = Common::swap16(value);
std::memcpy(GetPointer(address), &swapped_value, sizeof(u16)); CopyToEmu(address, &swapped_value, sizeof(swapped_value));
} }
void Write_U32(u32 value, u32 address) void Write_U32(u32 value, u32 address)
{ {
u32 swapped_value = Common::swap32(value); u32 swapped_value = Common::swap32(value);
std::memcpy(GetPointer(address), &swapped_value, sizeof(u32)); CopyToEmu(address, &swapped_value, sizeof(swapped_value));
} }
void Write_U64(u64 value, u32 address) void Write_U64(u64 value, u32 address)
{ {
u64 swapped_value = Common::swap64(value); u64 swapped_value = Common::swap64(value);
std::memcpy(GetPointer(address), &swapped_value, sizeof(u64)); CopyToEmu(address, &swapped_value, sizeof(swapped_value));
} }
void Write_U32_Swap(u32 value, u32 address) void Write_U32_Swap(u32 value, u32 address)
{ {
std::memcpy(GetPointer(address), &value, sizeof(u32)); CopyToEmu(address, &value, sizeof(value));
} }
void Write_U64_Swap(u64 value, u32 address) void Write_U64_Swap(u64 value, u32 address)
{ {
std::memcpy(GetPointer(address), &value, sizeof(u64)); CopyToEmu(address, &value, sizeof(value));
} }
} // namespace Memory } // namespace Memory

View File

@ -74,6 +74,7 @@ void Clear();
// emulated hardware outside the CPU. Use "Device_" prefix. // emulated hardware outside the CPU. Use "Device_" prefix.
std::string GetString(u32 em_address, size_t size = 0); std::string GetString(u32 em_address, size_t size = 0);
u8* GetPointer(u32 address); u8* GetPointer(u32 address);
u8* GetPointerForRange(u32 address, size_t size);
void CopyFromEmu(void* data, u32 address, size_t size); void CopyFromEmu(void* data, u32 address, size_t size);
void CopyToEmu(u32 address, const void* data, size_t size); void CopyToEmu(u32 address, const void* data, size_t size);
void Memset(u32 address, u8 value, size_t size); void Memset(u32 address, u8 value, size_t size);
@ -92,7 +93,7 @@ void Write_U64_Swap(u64 var, u32 address);
template <typename T> template <typename T>
void CopyFromEmuSwapped(T* data, u32 address, size_t size) void CopyFromEmuSwapped(T* data, u32 address, size_t size)
{ {
const T* src = reinterpret_cast<T*>(GetPointer(address)); const T* src = reinterpret_cast<T*>(GetPointerForRange(address, size));
if (src == nullptr) if (src == nullptr)
return; return;
@ -104,7 +105,7 @@ void CopyFromEmuSwapped(T* data, u32 address, size_t size)
template <typename T> template <typename T>
void CopyToEmuSwapped(u32 address, const T* data, size_t size) void CopyToEmuSwapped(u32 address, const T* data, size_t size)
{ {
T* dest = reinterpret_cast<T*>(GetPointer(address)); T* dest = reinterpret_cast<T*>(GetPointerForRange(address, size));
if (dest == nullptr) if (dest == nullptr)
return; return;