remap_vmalloc_range — map vmalloc pages to userspace
vma to cover (map full range of vma)
vmalloc memory
number of pages into addr before first page to map
0 for success, -Exxx on failure
This function checks that addr is a valid vmalloc'ed area, and that it is big enough to cover the vma. Will return failure if that criteria isn't met.
Similar to remap_pfn_range (see mm/memory.c)