[PATCH] mm, hugetlb: Avoid double clearing for hugetlb pages

Michal Hocko mhocko at suse.com
Thu Oct 22 08:55:57 UTC 2020


On Thu 22-10-20 10:04:50, David Hildenbrand wrote:
[...]
> > None of that would address the original point of this thread, the global
> > init_on_alloc parameter.
> 
> Yes, but I guess we're past that: whatever leaves the buddy shall be
> zeroed out. That's the whole point of that security hardening mechanism.

Hugetlb can control its zeroying behavior via mount option (for
MAP_HUGETLB controled by a command line parameter). If the page fault
handler can recognize the pre-initialized pages then both init_on* can
be implemented along with such a hugetlb specific mechanism.
-- 
Michal Hocko
SUSE Labs



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