QUALCOMM Incorporated
Increasing address space layout randomization entropy via page remapping and rotations

Abstract:

Various embodiments include methods and devices for generating a memory map configured to map virtual addresses of pages to physical addresses, in which pages of a same size are grouped into regions. The embodiments may include adding a first entry for a first additional page to a first region in the memory map, shifting virtual addresses of the first region to accommodate a shift of virtual addresses of the first region allocated for code by a sub-page granular shift amount, mapping shifted virtual addresses of the first entry for the first additional page to physical address mapped to a first lowest shifted virtually addressed page of the first region, and shifting the virtual addresses of the first region allocated for code by a sub-page granular shift amount, in which the virtual addresses of the first region allocated for code partially shift into the first entry for the first additional page.