नोट
इस पेज तक पहुँच के लिए प्रमाणन की आवश्यकता होती है. आप साइन इन करने या निर्देशिकाओं को बदलने का प्रयास कर सकते हैं.
इस पेज तक पहुँच के लिए प्रमाणन की आवश्यकता होती है. आप निर्देशिकाओं को बदलने का प्रयास कर सकते हैं.
A driver can't directly access memory through user-mode virtual addresses unless it's:
- Running in the context of the user-mode thread that caused the driver's current I/O operation.
- Using that thread's virtual addresses.
Drivers should use the User-mode Accessors (UMA) interface to access user-mode memory safely.
Only highest-level drivers, such as FSDs, can be sure their dispatch routines will be called in the context of such a user-mode thread. A highest-level driver can call MmProbeAndLockPages to lock down a user buffer before setting up an IRP for lower drivers.
Lowest-level and intermediate drivers that set up their device objects for buffered I/O or direct I/O can rely on the I/O manager or a highest-level driver to pass valid access to locked-down user buffers or to system-space buffers in IRPs.