kernel/svc: Implement svcUnmapProcessCodeMemory

Essentially performs the inverse of svcMapProcessCodeMemory. This unmaps
the aliasing region first, then restores the general traits of the
aliased memory.

What this entails, is:

- Restoring Read/Write permissions to the VMA.
- Restoring its memory state to reflect it as a general heap memory region.
- Clearing the memory attributes on the region.
master
Lioncash 2019-04-12 00:38:54 +07:00
parent 76a2465655
commit 4d293bb5cb
3 changed files with 143 additions and 1 deletions

@ -1257,6 +1257,74 @@ static ResultCode MapProcessCodeMemory(Core::System& system, Handle process_hand
return vm_manager.MapCodeMemory(dst_address, src_address, size);
}
ResultCode UnmapProcessCodeMemory(Core::System& system, Handle process_handle, u64 dst_address,
u64 src_address, u64 size) {
LOG_DEBUG(Kernel_SVC,
"called. process_handle=0x{:08X}, dst_address=0x{:016X}, src_address=0x{:016X}, "
"size=0x{:016X}",
process_handle, dst_address, src_address, size);
if (!Common::Is4KBAligned(dst_address)) {
LOG_ERROR(Kernel_SVC, "dst_address is not page-aligned (dst_address=0x{:016X}).",
dst_address);
return ERR_INVALID_ADDRESS;
}
if (!Common::Is4KBAligned(src_address)) {
LOG_ERROR(Kernel_SVC, "src_address is not page-aligned (src_address=0x{:016X}).",
src_address);
return ERR_INVALID_ADDRESS;
}
if (size == 0 || Common::Is4KBAligned(size)) {
LOG_ERROR(Kernel_SVC, "Size is zero or not page-aligned (size=0x{:016X}).", size);
return ERR_INVALID_SIZE;
}
if (!IsValidAddressRange(dst_address, size)) {
LOG_ERROR(Kernel_SVC,
"Destination address range overflows the address space (dst_address=0x{:016X}, "
"size=0x{:016X}).",
dst_address, size);
return ERR_INVALID_ADDRESS_STATE;
}
if (!IsValidAddressRange(src_address, size)) {
LOG_ERROR(Kernel_SVC,
"Source address range overflows the address space (src_address=0x{:016X}, "
"size=0x{:016X}).",
src_address, size);
return ERR_INVALID_ADDRESS_STATE;
}
const auto& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
auto process = handle_table.Get<Process>(process_handle);
if (!process) {
LOG_ERROR(Kernel_SVC, "Invalid process handle specified (handle=0x{:08X}).",
process_handle);
return ERR_INVALID_HANDLE;
}
auto& vm_manager = process->VMManager();
if (!vm_manager.IsWithinAddressSpace(src_address, size)) {
LOG_ERROR(Kernel_SVC,
"Source address range is not within the address space (src_address=0x{:016X}, "
"size=0x{:016X}).",
src_address, size);
return ERR_INVALID_ADDRESS_STATE;
}
if (!vm_manager.IsWithinASLRRegion(dst_address, size)) {
LOG_ERROR(Kernel_SVC,
"Destination address range is not within the ASLR region (dst_address=0x{:016X}, "
"size=0x{:016X}).",
dst_address, size);
return ERR_INVALID_MEMORY_RANGE;
}
return vm_manager.UnmapCodeMemory(dst_address, src_address, size);
}
/// Exits the current process
static void ExitProcess(Core::System& system) {
auto* current_process = system.Kernel().CurrentProcess();
@ -2286,7 +2354,7 @@ static const FunctionDef SVC_Table[] = {
{0x75, nullptr, "UnmapProcessMemory"},
{0x76, SvcWrap<QueryProcessMemory>, "QueryProcessMemory"},
{0x77, SvcWrap<MapProcessCodeMemory>, "MapProcessCodeMemory"},
{0x78, nullptr, "UnmapProcessCodeMemory"},
{0x78, SvcWrap<UnmapProcessCodeMemory>, "UnmapProcessCodeMemory"},
{0x79, nullptr, "CreateProcess"},
{0x7A, nullptr, "StartProcess"},
{0x7B, nullptr, "TerminateProcess"},

@ -331,6 +331,57 @@ ResultCode VMManager::MapCodeMemory(VAddr dst_address, VAddr src_address, u64 si
return ReprotectRange(dst_address, size, VMAPermission::Read);
}
ResultCode VMManager::UnmapCodeMemory(VAddr dst_address, VAddr src_address, u64 size) {
constexpr auto ignore_attribute = MemoryAttribute::LockedForIPC | MemoryAttribute::DeviceMapped;
const auto src_check_result = CheckRangeState(
src_address, size, MemoryState::All, MemoryState::Heap, VMAPermission::None,
VMAPermission::None, MemoryAttribute::Mask, MemoryAttribute::Locked, ignore_attribute);
if (src_check_result.Failed()) {
return src_check_result.Code();
}
// Yes, the kernel only checks the first page of the region.
const auto dst_check_result =
CheckRangeState(dst_address, Memory::PAGE_SIZE, MemoryState::FlagModule,
MemoryState::FlagModule, VMAPermission::None, VMAPermission::None,
MemoryAttribute::Mask, MemoryAttribute::None, ignore_attribute);
if (dst_check_result.Failed()) {
return dst_check_result.Code();
}
const auto dst_memory_state = std::get<MemoryState>(*dst_check_result);
const auto dst_contiguous_check_result = CheckRangeState(
dst_address, size, MemoryState::All, dst_memory_state, VMAPermission::None,
VMAPermission::None, MemoryAttribute::Mask, MemoryAttribute::None, ignore_attribute);
if (dst_contiguous_check_result.Failed()) {
return dst_contiguous_check_result.Code();
}
const auto unmap_result = UnmapRange(dst_address, size);
if (unmap_result.IsError()) {
return unmap_result;
}
// With the mirrored portion unmapped, restore the original region's traits.
const auto src_vma_result = CarveVMARange(src_address, size);
if (src_vma_result.Failed()) {
return src_vma_result.Code();
}
auto src_vma_iter = *src_vma_result;
src_vma_iter->second.state = MemoryState::Heap;
src_vma_iter->second.attribute = MemoryAttribute::None;
Reprotect(src_vma_iter, VMAPermission::ReadWrite);
if (dst_memory_state == MemoryState::ModuleCode) {
Core::System::GetInstance().InvalidateCpuInstructionCaches();
}
return unmap_result;
}
MemoryInfo VMManager::QueryMemory(VAddr address) const {
const auto vma = FindVMA(address);
MemoryInfo memory_info{};

@ -441,6 +441,29 @@ public:
///
ResultCode MapCodeMemory(VAddr dst_address, VAddr src_address, u64 size);
/// Unmaps a region of memory designated as code module memory.
///
/// @param dst_address The base address of the memory region aliasing the source memory region.
/// @param src_address The base address of the memory region being aliased.
/// @param size The size of the memory region to unmap in bytes.
///
/// @pre Both memory ranges lie within the actual addressable address space.
///
/// @pre The memory region being unmapped has been previously been mapped
/// by a call to MapCodeMemory.
///
/// @post After execution of the function, if successful. the aliasing memory region
/// will be unmapped and the aliased region will have various traits about it
/// restored to what they were prior to the original mapping call preceding
/// this function call.
/// <p>
/// What this also entails is as follows:
/// 1. The state of the memory region will now indicate a general heap region.
/// 2. All memory attributes for the memory region are cleared.
/// 3. Memory permissions for the region are restored to user read/write.
///
ResultCode UnmapCodeMemory(VAddr dst_address, VAddr src_address, u64 size);
/// Queries the memory manager for information about the given address.
///
/// @param address The address to query the memory manager about for information.