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    SubjectRe: [PATCH 4.9 20/76] powerpc/64: Disable the speculation barrier from the command line
    Date
    Diana Madalina Craciun <diana.craciun@nxp.com> writes:
    > Hi,
    >
    > I have tested the patches on NXP platforms and they worked as expected.

    Thanks Diana.

    cheers

    > On 4/15/2019 9:45 PM, Greg Kroah-Hartman wrote:
    >> commit cf175dc315f90185128fb061dc05b6fbb211aa2f upstream.
    >>
    >> The speculation barrier can be disabled from the command line
    >> with the parameter: "nospectre_v1".
    >>
    >> Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
    >> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    >> Signed-off-by: Sasha Levin <sashal@kernel.org>
    >> ---
    >> arch/powerpc/kernel/security.c | 12 +++++++++++-
    >> 1 file changed, 11 insertions(+), 1 deletion(-)
    >>
    >> diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
    >> index bf298d0c475f..813e38ff81ce 100644
    >> --- a/arch/powerpc/kernel/security.c
    >> +++ b/arch/powerpc/kernel/security.c
    >> @@ -17,6 +17,7 @@
    >> unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
    >>
    >> bool barrier_nospec_enabled;
    >> +static bool no_nospec;
    >>
    >> static void enable_barrier_nospec(bool enable)
    >> {
    >> @@ -43,9 +44,18 @@ void setup_barrier_nospec(void)
    >> enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
    >> security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR);
    >>
    >> - enable_barrier_nospec(enable);
    >> + if (!no_nospec)
    >> + enable_barrier_nospec(enable);
    >> }
    >>
    >> +static int __init handle_nospectre_v1(char *p)
    >> +{
    >> + no_nospec = true;
    >> +
    >> + return 0;
    >> +}
    >> +early_param("nospectre_v1", handle_nospectre_v1);
    >> +
    >> #ifdef CONFIG_DEBUG_FS
    >> static int barrier_nospec_set(void *data, u64 val)
    >> {
    >> --
    >> 2.19.1
    >>
    >>
    >>
    >>

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