On 2021-06-18 12:19, Neel Chauhan wrote:
I'm not sure. I'll just note that the Linux code appears to be trying
to map a set of pages belonging to a scatter-gather list. Taking the
physical address of the first page and assuming that all subsequent
pages are physically contiguous doesn't seem correct, but this is what
is happening in that loop, since each iteration simply increments pa
by
PAGE_SIZE.
Good news! While I don't have a fix, I have figured out what the issue
is.
Apparently, the vm_start values is for some reason coming as 0 when it
is passed into vm_fault_cpu(). That's why it's giving these errors: of
course the address at 0 is mapped, it is (probably) used by the kernel.
I will look more into it tomorrow, but my brother has come over to
Seattle from Connecticut so I may not be able to dedicate as much time
as I would like to.
-Neel (nc@)
