arm64, mm: make randomization selected by generic topdown mmap layout

This commits selects ARCH_HAS_ELF_RANDOMIZE when an arch uses the generic
topdown mmap layout functions so that this security feature is on by
default.

Note that this commit also removes the possibility for arm64 to have elf
randomization and no MMU: without MMU, the security added by randomization
is worth nothing.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexandre Ghiti <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Kees Cook <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Burton <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Russell King <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Alexandre Ghiti 2019-09-23 15:38:50 -07:00 • committed by Linus Torvalds
commit e7142bf5d2
4 changed files with 10 additions and 11 deletions

View file

@ -715,6 +715,7 @@ config HAVE_ARCH_COMPAT_MMAP_BASES
config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
bool
depends on MMU
select ARCH_HAS_ELF_RANDOMIZE
config HAVE_COPY_THREAD_TLS
bool