mm/mremap: allow moves within the same VMA for stack moves

For the stack move happening in shift_arg_pages(), the move is happening
within the same VMA which spans the old and new ranges.

In case the aligned address happens to fall within that VMA, allow such
moves and don't abort the mremap alignment optimization.

In the regular non-stack mremap case, we cannot allow any such moves as
will end up destroying some part of the mapping (either the source of the
move, or part of the existing mapping).  So just avoid it for stack moves.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Joel Fernandes (Google) <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Lokesh Gidra <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions