ReadHandleFromUser - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// usermode_accessors.h
HANDLE ReadHandleFromUser(
const volatile HANDLE *Source
);
View the official Windows Driver Kit DDI referenceNo description available.
The ReadHandleFromUser function safely reads a HANDLE value from user-mode memory.
Source[in] A pointer to the user-mode memory location from which to read the HANDLE value.
ReadHandleFromUser returns the HANDLE value read from the specified user-mode memory address.
This function provides a safe way to read a HANDLE value from user-mode memory. It ensures the provided address is a user-mode address before reading it.
This function doesn't enforce alignment.
It raises a structured exception if the memory access fails, such as when the source address isn't a user-mode address or is inaccessible.
This function will never be optimized away by the compiler, nor will the compiler create additional accesses to this memory location before the function is called or after the function returns (unless the source code explicitly performs these accesses). The memory access is performed with memory_order_relaxed semantics.
This function works on all versions of Windows, not just the latest. You need to consume the latest WDK to get the function declaration from the usermode_accessors.h header. You also need the library (umaccess.lib) from the latest WDK. However, the resulting driver will run fine on older versions of Windows.