ARM64: mm: Make PAGE_NONE pages read only and no-execute.
If we consider the following code sequence:
my_pte = pte_modify(entry, myprot);
x = pte_write(my_pte);
y = pte_exec(my_pte);
If myprot comes from a PROT_NONE page, then x and y will both be
true which is undesireable behaviour.
This patch sets the no-execute and read-only bits for PAGE_NONE
such that the code above will return false for both x and y.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
1 file changed