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Diffstat (limited to 'Kernel/Source/KernelHeap.cxx')
| -rw-r--r-- | Kernel/Source/KernelHeap.cxx | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/Kernel/Source/KernelHeap.cxx b/Kernel/Source/KernelHeap.cxx new file mode 100644 index 00000000..d0037ec3 --- /dev/null +++ b/Kernel/Source/KernelHeap.cxx @@ -0,0 +1,169 @@ +/* ------------------------------------------- + + Copyright SoftwareLabs + +------------------------------------------- */ + +#include <KernelKit/DebugOutput.hpp> +#include <KernelKit/HError.hpp> +#include <KernelKit/KernelHeap.hpp> +#include <NewKit/Crc32.hpp> +#include <NewKit/PageManager.hpp> + +//! @file KernelHeap.cxx +//! @brief Kernel allocator. + +#define kKernelHeapMagic (0xD4D7D5) +#define kKernelHeapHeaderPaddingSz (16U) + +namespace NewOS +{ + STATIC SizeT kHeapCount = 0UL; + STATIC PageManager kHeapPageManager; + + namespace Detail + { + /// @brief Kernel heap information block. + /// Located before the address bytes. + /// | HIB | ADDRESS | + struct PACKED HeapInformationBlock final + { + ///! @brief 32-bit value which contains the magic number of the executable. + UInt32 fMagic; + ///! @brief Boolean value which tells if the pointer is allocated. + Boolean fPresent; + ///! @brief 32-bit CRC checksum + UInt32 fCRC32; + /// @brief 64-bit pointer size. + SizeT fTargetPtrSize; + /// @brief 64-bit target pointer. + UIntPtr fTargetPtr; + UInt8 fPadding[kKernelHeapHeaderPaddingSz]; + }; + + typedef HeapInformationBlock* HeapInformationBlockPtr; + } // namespace Detail + + /// @brief allocate chunk of memory. + /// @param sz size of pointer + /// @param rw read write (true to enable it) + /// @param user is it accesible by user processes? + /// @return the pointer + VoidPtr ke_new_ke_heap(SizeT sz, const bool rw, const bool user) + { + if (sz == 0) + ++sz; + + auto wrapper = kHeapPageManager.Request(rw, user, false, sz); + + Detail::HeapInformationBlockPtr heapInfo = + reinterpret_cast<Detail::HeapInformationBlockPtr>( + wrapper.VirtualAddress()); + + heapInfo->fTargetPtrSize = sz; + heapInfo->fMagic = kKernelHeapMagic; + heapInfo->fCRC32 = 0; // dont fill it for now. + heapInfo->fTargetPtr = wrapper.VirtualAddress(); + + ++kHeapCount; + + return reinterpret_cast<VoidPtr>(wrapper.VirtualAddress() + + sizeof(Detail::HeapInformationBlock)); + } + + /// @brief Declare pointer as free. + /// @param heapPtr the pointer. + /// @return + Int32 ke_delete_ke_heap(VoidPtr heapPtr) + { + if (kHeapCount < 1) + return -kErrorInternal; + if (((IntPtr)heapPtr - sizeof(Detail::HeapInformationBlock)) <= 0) + return -kErrorInternal; + if (((IntPtr)heapPtr - kBadPtr) < 0) + return -kErrorInternal; + + Detail::HeapInformationBlockPtr virtualAddress = + reinterpret_cast<Detail::HeapInformationBlockPtr>( + (UIntPtr)heapPtr - sizeof(Detail::HeapInformationBlock)); + + if (virtualAddress && virtualAddress->fMagic == kKernelHeapMagic) + { + if (!virtualAddress->fPresent) + { + return -kErrorHeapNotPresent; + } + + if (virtualAddress->fCRC32 != 0) + { + if (virtualAddress->fCRC32 != + ke_calculate_crc32((Char*)virtualAddress->fTargetPtr, + virtualAddress->fTargetPtrSize)) + { + ke_stop(RUNTIME_CHECK_POINTER); + } + } + + virtualAddress->fTargetPtrSize = 0UL; + virtualAddress->fPresent = false; + virtualAddress->fTargetPtr = 0; + virtualAddress->fCRC32 = 0; + virtualAddress->fMagic = 0; + + PTEWrapper pageWrapper(false, false, false, (UIntPtr)virtualAddress); + Ref<PTEWrapper*> pteAddress{&pageWrapper}; + + kHeapPageManager.Free(pteAddress); + + --kHeapCount; + return 0; + } + + return -kErrorInternal; + } + + /// @brief Check if pointer is a valid kernel pointer. + /// @param heapPtr the pointer + /// @return if it exists. + Boolean ke_is_valid_heap(VoidPtr heapPtr) + { + if (kHeapCount < 1) + return false; + + if (heapPtr) + { + Detail::HeapInformationBlockPtr virtualAddress = + reinterpret_cast<Detail::HeapInformationBlockPtr>( + (UIntPtr)heapPtr - sizeof(Detail::HeapInformationBlock)); + + if (virtualAddress->fPresent && virtualAddress->fMagic == kKernelHeapMagic) + { + return true; + } + } + + return false; + } + + /// @brief Protect the heap with a CRC value. + /// @param heapPtr HIB pointer. + /// @return if it valid: point has crc now., otherwise fail. + Boolean ke_protect_ke_heap(VoidPtr heapPtr) + { + if (heapPtr) + { + Detail::HeapInformationBlockPtr virtualAddress = + reinterpret_cast<Detail::HeapInformationBlockPtr>( + (UIntPtr)heapPtr - sizeof(Detail::HeapInformationBlock)); + + if (virtualAddress->fPresent && kKernelHeapMagic == virtualAddress->fMagic) + { + virtualAddress->fCRC32 = + ke_calculate_crc32((Char*)heapPtr, virtualAddress->fTargetPtrSize); + return true; + } + } + + return false; + } +} // namespace NewOS |