mm/mempolicy: protect task interleave functions with tsk->mems_allowed_seq

In the event of rebind, pol->nodemask can change at the same time as an
allocation occurs.  We can detect this with tsk->mems_allowed_seq and
prevent a miscount or an allocation failure from occurring.

The same thing happens in the allocators to detect failure, but this can
prevent spurious failures in a much smaller critical section.

[[email protected]: weighted interleave checks wrong parameter]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Gregory Price <[email protected]>
Suggested-by: "Huang, Ying" <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Hasan Al Maruf <[email protected]>
Cc: Honggyu Kim <[email protected]>
Cc: Hyeongtak Ji <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rakie Kim <[email protected]>
Cc: Ravi Jonnalagadda <[email protected]>
Cc: Srinivasulu Thanneeru <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions