s390: correct nospec auto detection init order
commitc2d46e7be467d06ee217fad41261d999fee777fb
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 27 Apr 2018 05:37:01 +0000 (27 07:37 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 29 Apr 2018 05:50:04 +0000 (29 07:50 +0200)
treeb64144d37a09b84f3a41a51fbd34f83840075197
parent6aa300a00e7e6dfdbd4e914e7bbe4864d30a76b5
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