Re: [PATCH mm-unstable v1 04/20] mm: add early FAULT_FLAG_UNSHARE consistency checks

Vlastimil Babka
2022-11-18T16:46:05Z

On 11/16/22 11:26, David Hildenbrand wrote:
> For now, FAULT_FLAG_UNSHARE only applies to anonymous pages, which
> implies a COW mapping. Let's hide FAULT_FLAG_UNSHARE early if we're not
> dealing with a COW mapping, such that we treat it like a read fault as
> documented and don't have to worry about the flag throughout all fault
> handlers.
>
> While at it, centralize the check for mutual exclusion of
> FAULT_FLAG_UNSHARE and FAULT_FLAG_WRITE and just drop the check that
> either flag is set in the WP handler.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> mm/huge_memory.c | 3 ---
> mm/hugetlb.c | 5 -----
> mm/memory.c | 23 ++++++++++++++++++++---
> 3 files changed, 20 insertions(+), 11 deletions(-)

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>