// Allocate space and return a pointer to it. The size is the minimum
// size requested and it is updated with the actual space allocated.
// Returns NULL if it cannot allocate the space.
void *OSMem::Allocate(size_t &space, unsigned permissions)
{
// Get the page size and round up to that multiple.
SYSTEM_INFO sysInfo;
GetSystemInfo(&sysInfo);
DWORD pageSize = sysInfo.dwPageSize;
space = (space + pageSize-1) & ~(pageSize-1);
return VirtualAlloc(0, space, MEM_RESERVE|MEM_COMMIT, ConvertPermissions(permissions));
}
// Allocate space and return a pointer to it. The size is the minimum
// size requested and it is updated with the actual space allocated.
// Returns NULL if it cannot allocate the space.
void *OSMem::Allocate(size_t &space, unsigned permissions)
{
int prot = ConvertPermissions(permissions);
// Round up to an integral number of pages.
int pageSize = getpagesize();
space = (space + pageSize-1) & ~(pageSize-1);
int fd = -1; // This value is required by FreeBSD. Linux doesn't care
void *result = mmap(0, space, prot, MAP_PRIVATE|MAP_ANON, fd, 0);
// Convert MAP_FAILED (-1) into NULL
if (result == MAP_FAILED)
return 0;
return result;
}
// Adjust the permissions on a segment. This must apply to the
// whole of a segment.
bool OSMem::SetPermissions(void *p, size_t space, unsigned permissions)
{
DWORD oldProtect;
return VirtualProtect(p, space, ConvertPermissions(permissions), &oldProtect) == TRUE;
}
// Adjust the permissions on a segment. This must apply to the
// whole of a segment.
bool OSMem::SetPermissions(void *p, size_t space, unsigned permissions)
{
int res = mprotect(FIXTYPE p, space, ConvertPermissions(permissions));
return res != -1;
}
ResultCode SharedMemory::Map(Process* target_process, VAddr address, MemoryPermission permissions,
MemoryPermission other_permissions) {
MemoryPermission own_other_permissions =
target_process == owner_process ? this->permissions : this->other_permissions;
// Automatically allocated memory blocks can only be mapped with other_permissions = DontCare
if (base_address == 0 && other_permissions != MemoryPermission::DontCare) {
return ERR_INVALID_COMBINATION;
}
// Error out if the requested permissions don't match what the creator process allows.
if (static_cast<u32>(permissions) & ~static_cast<u32>(own_other_permissions)) {
LOG_ERROR(Kernel, "cannot map id=%u, address=0x%08X name=%s, permissions don't match",
GetObjectId(), address, name.c_str());
return ERR_INVALID_COMBINATION;
}
// Heap-backed memory blocks can not be mapped with other_permissions = DontCare
if (base_address != 0 && other_permissions == MemoryPermission::DontCare) {
LOG_ERROR(Kernel, "cannot map id=%u, address=0x%08X name=%s, permissions don't match",
GetObjectId(), address, name.c_str());
return ERR_INVALID_COMBINATION;
}
// Error out if the provided permissions are not compatible with what the creator process needs.
if (other_permissions != MemoryPermission::DontCare &&
static_cast<u32>(this->permissions) & ~static_cast<u32>(other_permissions)) {
LOG_ERROR(Kernel, "cannot map id=%u, address=0x%08X name=%s, permissions don't match",
GetObjectId(), address, name.c_str());
return ERR_WRONG_PERMISSION;
}
// TODO(Subv): Check for the Shared Device Mem flag in the creator process.
/*if (was_created_with_shared_device_mem && address != 0) {
return ResultCode(ErrorDescription::InvalidCombination, ErrorModule::OS,
ErrorSummary::InvalidArgument, ErrorLevel::Usage);
}*/
// TODO(Subv): The same process that created a SharedMemory object
// can not map it in its own address space unless it was created with addr=0, result 0xD900182C.
if (address != 0) {
if (address < Memory::HEAP_VADDR || address + size >= Memory::SHARED_MEMORY_VADDR_END) {
LOG_ERROR(Kernel, "cannot map id=%u, address=0x%08X name=%s, invalid address",
GetObjectId(), address, name.c_str());
return ERR_INVALID_ADDRESS;
}
}
VAddr target_address = address;
if (base_address == 0 && target_address == 0) {
// Calculate the address at which to map the memory block.
target_address = Memory::PhysicalToVirtualAddress(linear_heap_phys_address).value();
}
// Map the memory block into the target process
auto result = target_process->vm_manager.MapMemoryBlock(
target_address, backing_block, backing_block_offset, size, MemoryState::Shared);
if (result.Failed()) {
LOG_ERROR(
Kernel,
"cannot map id=%u, target_address=0x%08X name=%s, error mapping to virtual memory",
GetObjectId(), target_address, name.c_str());
return result.Code();
}
return target_process->vm_manager.ReprotectRange(target_address, size,
ConvertPermissions(permissions));
}
SharedPtr<SharedMemory> SharedMemory::Create(SharedPtr<Process> owner_process, u32 size,
MemoryPermission permissions,
MemoryPermission other_permissions, VAddr address,
MemoryRegion region, std::string name) {
SharedPtr<SharedMemory> shared_memory(new SharedMemory);
shared_memory->owner_process = owner_process;
shared_memory->name = std::move(name);
shared_memory->size = size;
shared_memory->permissions = permissions;
shared_memory->other_permissions = other_permissions;
if (address == 0) {
// We need to allocate a block from the Linear Heap ourselves.
// We'll manually allocate some memory from the linear heap in the specified region.
MemoryRegionInfo* memory_region = GetMemoryRegion(region);
auto& linheap_memory = memory_region->linear_heap_memory;
ASSERT_MSG(linheap_memory->size() + size <= memory_region->size,
"Not enough space in region to allocate shared memory!");
shared_memory->backing_block = linheap_memory;
shared_memory->backing_block_offset = linheap_memory->size();
// Allocate some memory from the end of the linear heap for this region.
linheap_memory->insert(linheap_memory->end(), size, 0);
memory_region->used += size;
shared_memory->linear_heap_phys_address =
Memory::FCRAM_PADDR + memory_region->base + shared_memory->backing_block_offset;
// Increase the amount of used linear heap memory for the owner process.
if (shared_memory->owner_process != nullptr) {
shared_memory->owner_process->linear_heap_used += size;
}
// Refresh the address mappings for the current process.
if (Kernel::g_current_process != nullptr) {
Kernel::g_current_process->vm_manager.RefreshMemoryBlockMappings(linheap_memory.get());
}
} else {
// TODO(Subv): What happens if an application tries to create multiple memory blocks
// pointing to the same address?
auto& vm_manager = shared_memory->owner_process->vm_manager;
// The memory is already available and mapped in the owner process.
auto vma = vm_manager.FindVMA(address)->second;
// Copy it over to our own storage
shared_memory->backing_block = std::make_shared<std::vector<u8>>(
vma.backing_block->data() + vma.offset, vma.backing_block->data() + vma.offset + size);
shared_memory->backing_block_offset = 0;
// Unmap the existing pages
vm_manager.UnmapRange(address, size);
// Map our own block into the address space
vm_manager.MapMemoryBlock(address, shared_memory->backing_block, 0, size,
MemoryState::Shared);
// Reprotect the block with the new permissions
vm_manager.ReprotectRange(address, size, ConvertPermissions(permissions));
}
shared_memory->base_address = address;
return shared_memory;
}
