mirror of
				https://github.com/PabloMK7/citra.git
				synced 2025-10-30 21:30:04 +00:00 
			
		
		
		
	Kernel/SharedMemory: Don't take over and unmap the source memory block when creating a shared memory, just reference it.
Also reference the right offset into the backing block for the requested address.
This commit is contained in:
		
							parent
							
								
									5ba48c1610
								
							
						
					
					
						commit
						b18589ecf7
					
				
					 1 changed files with 12 additions and 15 deletions
				
			
		|  | @ -55,22 +55,19 @@ SharedPtr<SharedMemory> SharedMemory::Create(SharedPtr<Process> owner_process, u | |||
|             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)); | ||||
|         auto vma = vm_manager.FindVMA(address); | ||||
|         ASSERT_MSG(vma != vm_manager.vma_map.end(), "Invalid memory address"); | ||||
|         ASSERT_MSG(vma->second.backing_block, "Backing block doesn't exist for address"); | ||||
| 
 | ||||
|         // The returned VMA might be a bigger one encompassing the desired address.
 | ||||
|         auto vma_offset = address - vma->first; | ||||
|         ASSERT_MSG(vma_offset + size <= vma->second.size, | ||||
|                    "Shared memory exceeds bounds of mapped block"); | ||||
| 
 | ||||
|         shared_memory->backing_block = vma->second.backing_block; | ||||
|         shared_memory->backing_block_offset = vma->second.offset + vma_offset; | ||||
|     } | ||||
| 
 | ||||
|     shared_memory->base_address = address; | ||||
|  | @ -184,4 +181,4 @@ u8* SharedMemory::GetPointer(u32 offset) { | |||
|     return backing_block->data() + backing_block_offset + offset; | ||||
| } | ||||
| 
 | ||||
| } // namespace
 | ||||
| } // namespace Kernel
 | ||||
|  |  | |||
		Loading…
	
	Add table
		Add a link
		
	
		Reference in a new issue