s390: correct nospec auto detection init order
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 27 Apr 2018 05:36:42 +0000 (07:36 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 29 Apr 2018 09:33:16 +0000 (11:33 +0200)
commitf836b34fb0562cf193a076769a5adf71b030f59f
tree9c7ecfa69ce0c883e60e1a825a7c31a6d57bca2d
parentfce1bf054f0bc1dec6fef6cf5840c6ad7c662e17
s390: correct nospec auto detection init order

[ Upstream commit 6a3d1e81a434fc311f224b8be77258bafc18ccc6 ]

With CONFIG_EXPOLINE_AUTO=y the call of spectre_v2_auto_early() via
early_initcall is done *after* the early_param functions. This
overwrites any settings done with the nobp/no_spectre_v2/spectre_v2
parameters. The code patching for the kernel is done after the
evaluation of the early parameters but before the early_initcall
is done. The end result is a kernel image that is patched correctly
but the kernel modules are not.

Make sure that the nospec auto detection function is called before the
early parameters are evaluated and before the code patching is done.

Fixes: 6e179d64126b ("s390: add automatic detection of the spectre defense")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/s390/include/asm/nospec-branch.h
arch/s390/kernel/nospec-branch.c
arch/s390/kernel/setup.c