LLE Mapped Buffer: Addressed comments.

This commit is contained in:
NarcolepticK 2018-10-29 18:35:34 -04:00
parent 32aecd42a2
commit c97146226a

View File

@ -14,6 +14,68 @@
namespace Kernel {
void ScanForAndUnmapBuffer(std::array<u32, IPC::COMMAND_BUFFER_LENGTH>& dst_cmd_buf,
const std::size_t dst_command_size, std::size_t& target_index,
SharedPtr<Process> src_process, SharedPtr<Process> dst_process,
const VAddr source_address, const VAddr page_start, const u32 num_pages,
const u32 size, const IPC::MappedBufferPermissions permissions) {
while (target_index < dst_command_size) {
u32 desc = dst_cmd_buf[target_index++];
if (IPC::GetDescriptorType(desc) == IPC::DescriptorType::CopyHandle ||
IPC::GetDescriptorType(desc) == IPC::DescriptorType::MoveHandle) {
u32 num_handles = IPC::HandleNumberFromDesc(desc);
for (u32 j = 0; j < num_handles; ++j) {
target_index += 1;
}
continue;
}
if (IPC::GetDescriptorType(desc) == IPC::DescriptorType::CallingPid ||
IPC::GetDescriptorType(desc) == IPC::DescriptorType::StaticBuffer) {
target_index += 1;
continue;
}
if (IPC::GetDescriptorType(desc) == IPC::DescriptorType::MappedBuffer) {
VAddr dest_address = dst_cmd_buf[target_index];
IPC::MappedBufferDescInfo dest_descInfo{desc};
u32 dest_size = static_cast<u32>(dest_descInfo.size);
IPC::MappedBufferPermissions dest_permissions = dest_descInfo.perms;
if (dest_size == 0) {
target_index += 1;
continue;
}
ASSERT(permissions == dest_permissions && size == dest_size);
// Readonly buffers do not need to be copied over to the target
// process again because they were (presumably) not modified. This
// behavior is consistent with the real kernel.
if (permissions != IPC::MappedBufferPermissions::R) {
// Copy the modified buffer back into the target process
Memory::CopyBlock(*src_process, *dst_process, source_address, dest_address, size);
}
VAddr prev_reserve = page_start - Memory::PAGE_SIZE;
VAddr next_reserve = page_start + num_pages * Memory::PAGE_SIZE;
auto& prev_vma = src_process->vm_manager.FindVMA(prev_reserve)->second;
auto& next_vma = src_process->vm_manager.FindVMA(next_reserve)->second;
ASSERT(prev_vma.meminfo_state == MemoryState::Reserved &&
next_vma.meminfo_state == MemoryState::Reserved);
// Unmap the buffer and guard pages from the source process
ResultCode result = src_process->vm_manager.UnmapRange(
page_start - Memory::PAGE_SIZE, (num_pages + 2) * Memory::PAGE_SIZE);
ASSERT(result == RESULT_SUCCESS);
target_index += 1;
break;
}
}
}
ResultCode TranslateCommandBuffer(SharedPtr<Thread> src_thread, SharedPtr<Thread> dst_thread,
VAddr src_address, VAddr dst_address, bool reply) {
@ -148,46 +210,11 @@ ResultCode TranslateCommandBuffer(SharedPtr<Thread> src_thread, SharedPtr<Thread
ASSERT(num_pages >= 1);
if (reply) {
// Scan the target's command buffer for the matching mapped buffer
while (target_index < dst_command_size) {
u32 desc = dst_cmd_buf[target_index++];
if (IPC::GetDescriptorType(desc) == IPC::DescriptorType::MappedBuffer) {
IPC::MappedBufferDescInfo dest_descInfo{desc};
VAddr dest_address = dst_cmd_buf[target_index];
u32 dest_size = static_cast<u32>(dest_descInfo.size);
IPC::MappedBufferPermissions dest_permissions = dest_descInfo.perms;
ASSERT(permissions == dest_permissions && size == dest_size);
// Readonly buffers do not need to be copied over to the target
// process again because they were (presumably) not modified. This
// behavior is consistent with the real kernel.
if (permissions != IPC::MappedBufferPermissions::R) {
// Copy the modified buffer back into the target process
Memory::CopyBlock(*src_process, *dst_process, source_address,
dest_address, size);
}
VAddr prev_reserve = page_start - Memory::PAGE_SIZE;
VAddr next_reserve = page_start + num_pages * Memory::PAGE_SIZE;
auto& prev_vma = src_process->vm_manager.FindVMA(prev_reserve)->second;
auto& next_vma = src_process->vm_manager.FindVMA(next_reserve)->second;
ASSERT(prev_vma.meminfo_state == MemoryState::Reserved &&
next_vma.meminfo_state == MemoryState::Reserved);
// Unmap the buffer and guard pages from the source process
ResultCode result = src_process->vm_manager.UnmapRange(
page_start - Memory::PAGE_SIZE, (num_pages + 2) * Memory::PAGE_SIZE);
ASSERT(result == RESULT_SUCCESS);
target_index += 1;
break;
}
target_index += 1;
}
// Scan the target's command buffer for the matching mapped buffer.
// The real kernel panics if you try to reply with an unsolicited MappedBuffer.
ScanForAndUnmapBuffer(dst_cmd_buf, dst_command_size, target_index, src_process,
dst_process, source_address, page_start, num_pages, size,
permissions);
i += 1;
break;