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5cf7f9a0 |
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09-Apr-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/mm: Enable full randomisation of memory mappings
Do like most other architectures and provide randomisation also to
"legacy" memory mappings, by adding the random factor to
mm->mmap_base in arch_pick_mmap_layout().
See commit 8b8addf891de ("x86/mm/32: Enable full randomization on
i386 and X86_32") for all explanations and benefits of that mmap
randomisation.
At the moment, slice_find_area_bottomup() doesn't use mm->mmap_base
but uses the fixed TASK_UNMAPPED_BASE instead.
slice_find_area_bottomup() being used as a fallback to
slice_find_area_topdown(), it can't use mm->mmap_base
directly.
Instead of always using TASK_UNMAPPED_BASE as base address, leave
it to the caller. When called from slice_find_area_topdown()
TASK_UNMAPPED_BASE is used. Otherwise mm->mmap_base is used.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/417fb10dde828534c73a03138b49621d74f4e5be.1649523076.git.christophe.leroy@csgroup.eu
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ab57bd75 |
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09-Apr-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/mm: Move get_unmapped_area functions to slice.c
hugetlb_get_unmapped_area() is now identical to the
generic version if only RADIX is enabled, so move it
to slice.c and let it fallback on the generic one
when HASH MMU is not compiled in.
Do the same with arch_get_unmapped_area() and
arch_get_unmapped_area_topdown().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b5d9c124e82889e0cb115c150915a0c0d84eb960.1649523076.git.christophe.leroy@csgroup.eu
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