s390: correct nospec auto detection init order
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 27 Apr 2018 05:36:56 +0000 (07:36 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 29 Apr 2018 09:32:00 +0000 (11:32 +0200)
commit906cd975f6d4bcfdf26a12f4e13e826d089a42a3
tree36e29a32c0d80653e629d3ce8fc2c47baecb6700
parentfa90b9a2b63e2d84d169cb640f47fc6d9af17c6c
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