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    Subject[PATCH 4.4 045/266] powerpc/64: Disable the speculation barrier from the command line
    Date
    From: Diana Craciun <diana.craciun@nxp.com>

    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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    arch/powerpc/kernel/security.c | 12 +++++++++++-
    1 file changed, 11 insertions(+), 1 deletion(-)

    --- 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)
    {

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