On Wed, Jun 23, 2021 at 10:39:31AM +0800, Chen Huang wrote: > Then when kernel handles the alignment_fault, it will not panic. As the > arm64 memory model spec said, when the address is not a multiple of the > element size, the access is unaligned. Unaligned accesses are allowed to > addresses marked as Normal, but not to Device regions. An unaligned access > to a Device region will trigger an exception (alignment fault). > > do_alignment_fault > do_bad_area > __do_kernel_fault > fixup_exception > > But that fixup cann't handle the unaligned copy, so the > copy_page_from_iter_atomic returns 0 and traps in loop. Looks like you need to fix your raw_copy_from_user(), then...
