tree 6f7832ca67de31a117dbb1b3346bfae3ec1a348e
parent fa7f9189e017213bad63b93a76de5c715cd62a96
author Michael Ellerman <mpe@ellerman.id.au> 1500015083 +1000
committer Michael Ellerman <mpe@ellerman.id.au> 1500371664 +1000

powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y

Currently even with STRICT_KERNEL_RWX we leave the __init text marked
executable after init, which is bad.

Add a hook to mark it NX (no-execute) before we free it, and implement
it for radix and hash.

Note that we use __init_end as the end address, not _einittext,
because overlaps_kernel_text() uses __init_end, because there are
additional executable sections other than .init.text between
__init_begin and __init_end.

Tested on radix and hash with:

  0:mon> p $__init_begin
  *** 400 exception occurred

Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>