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Subject[PATCH 4.14 031/107] powerpc/64: Disable the speculation barrier from the command line
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

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
@@ -16,6 +16,7 @@
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)
{
@@ -42,9 +43,18 @@ 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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