tree b27df1627344cfbe028fe2ebbdcae0bbddb8247c
parent 3d21543203675c6d63f9e7a4eab179ed89c8c1d0
author Michael Ellerman <mpe@ellerman.id.au> 1589981765 +1000
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1590593858 +0200

powerpc/64s: Disable STRICT_KERNEL_RWX

[ Upstream commit 8659a0e0efdd975c73355dbc033f79ba3b31e82c ]

Several strange crashes have been eventually traced back to
STRICT_KERNEL_RWX and its interaction with code patching.

Various paths in our ftrace, kprobes and other patching code need to
be hardened against patching failures, otherwise we can end up running
with partially/incorrectly patched ftrace paths, kprobes or jump
labels, which can then cause strange crashes.

Although fixes for those are in development, they're not -rc material.

There also seem to be problems with the underlying strict RWX logic,
which needs further debugging.

So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from
enabling the option and tripping over the bugs.

Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>