Re: [PATCH v3 2/5] kselftest: vm: Fix mdwe's mmap_FIXED test case

[Catalin Marinas]

On Tue, Jul 04, 2023 at 05:36:26PM +0200, Florent Revest wrote:
> I checked with the original author, the mmap_FIXED test case wasn't
> properly tested and fails. Currently, it maps two consecutive (non
> overlapping) pages and expects the second mapping to be denied by MDWE
> but these two pages have nothing to do with each other so MDWE is
> actually out of the picture here.
> 
> What the test actually intended to do was to remap a virtual address
> using MAP_FIXED. However, this operation unmaps the existing mapping and
> creates a new one so the va is backed by a new page and MDWE is again
> out of the picture, all remappings should succeed.
> 
> This patch keeps the test case to make it clear that this situation is
> expected to work.
> 
> Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Fixes: 4cf1fe34fd18 ("kselftest: vm: add tests for memory-deny-write-execute")

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>