On 2019-06-13 10:12, Anshuman Khandual wrote:
vmap_pte_range() returns an -EBUSY when it encounters a non-empty PTE.
But
currently vmap_pmd_range() unifies both -EBUSY and -ENOMEM return code
as
-ENOMEM and send it up the call chain which is wrong. Interestingly
enough
vmap_page_range_noflush() tests for the absolute error return value
from
vmap_p4d_range() but it does not help because -EBUSY has been merged
with
-ENOMEM. So all it can return is -ENOMEM. Fix this by testing for
absolute
error return from vmap_pmd_range() all the way up to vmap_p4d_range().
I could not find any real external caller of vmap API who really cares
about the errno, and frankly why they should? This is allocation path,
allocation failed - game over. When you step on -EBUSY case something
has gone completely wrong in your kernel, you get a big warning in
your dmesg and it is already does not matter what errno you get.
--
Roman
