My file system driver catched the IRP_MJ_WRITE action. And I got a valid Irp->UserBuffer , which length 4177 bytes. ( the Irp->MdlAddress is NULL )
But I can access only the front 0~4095 byte of the UserBuffer. And BOSD if my code access the bytes behind 4095. In windbg I can see the memory content only 0~4095. Behind that was fill with ‘?’ .
I try to use IoAllocateMdl to build a mdl , and use MmProbeAndLockPages to lock them in to physics memory. But MmProbeAndLockPages threw a exception.
I am sure my irql is PASSIVE_LEVEL , and my AccessMode is UserMode.
I am sure the buffer is correct and valid ( because the .exe is a test application, and i am the writer ).
How can I lock all the buff in to physical memory?
Make a breakpoint in this case. Repro it, stop on a breakpoint, and step down to xxxLockUserBuffer in the FSD. Will it fail? if no - with what arguments it calls MDL-related functions?
wrote in message news:xxxxx@ntfsd… > My file system driver catched the IRP_MJ_WRITE action. And I got a valid Irp->UserBuffer , which length 4177 bytes. ( the Irp->MdlAddress is NULL ) > > But I can access only the front 0~4095 byte of the UserBuffer. And BOSD if my code access the bytes behind 4095. In windbg I can see the memory content only 0~4095. Behind that was fill with ‘?’ . > > I try to use IoAllocateMdl to build a mdl , and use MmProbeAndLockPages to lock them in to physics memory. But MmProbeAndLockPages threw a exception. > > I am sure my irql is PASSIVE_LEVEL , and my AccessMode is UserMode. > I am sure the buffer is correct and valid ( because the .exe is a test application, and i am the writer ). > > How can I lock all the buff in to physical memory? >
