On Wed, 17 Jan 2018 10:48:36 +0100 Martin Schwidefsky <schwidefsky@xxxxxxxxxx> wrote: > Add the PPA instruction to the system entry and exit path to switch > the kernel to a different branch prediction behaviour. The instructions > are added via CPU alternatives and can be disabled with the "nospec" > or the "nobp=0" kernel parameter. If the default behaviour selected > with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be > used to enable the changed kernel branch prediction. > > Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> > --- > arch/s390/Kconfig | 17 +++++++++++++ > arch/s390/include/asm/processor.h | 1 + > arch/s390/kernel/alternative.c | 23 ++++++++++++++++++ > arch/s390/kernel/early.c | 2 ++ > arch/s390/kernel/entry.S | 50 ++++++++++++++++++++++++++++++++++++++- > arch/s390/kernel/ipl.c | 1 + > arch/s390/kernel/smp.c | 2 ++ > 7 files changed, 95 insertions(+), 1 deletion(-) Acked-by: Cornelia Huck <cohuck@xxxxxxxxxx> [This looks sane; but as I don't have insight into the details of the new instructions, I don't feel confident enough to give a R-b]
