Protection before reading paged memory from kernel

Question

I have kernel driver and I want to read the memory of a usermode app.

How can I check the paged memory if swapping will be success or not (when pages are written to the disk and we have problems with disk or whatever)?

Answer 1

@RbMm's answer is correct. If you are not at dispatch level, you wrap the probing of the memory in a __try/__except block with the filter set to catch the exception. You need to figure out from the exception or Mm whether the page is indeed not-present due to being completely invalid (ie, never allocated) or paged-out/demand-zero-inited/copy-on-write/etc.