[PATCH 4.9 34/61] powerpc/pseries: Set or clear security feature flags

Greg Kroah-Hartman
2018-06-05T17:05:47Z

From: Michael Ellerman <mpe@ellerman.id.au>

commit f636c14790ead6cc22cf62279b1f8d7e11a67116 upstream.

Now that we have feature flags for security related things, set or
clear them based on what we receive from the hypercall.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/platforms/pseries/setup.c | 43 +++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)

--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -66,6 +66,7 @@
#include <asm/reg.h>
#include <asm/plpar_wrappers.h>
#include <asm/kexec.h>
+#include <asm/security_features.h>

#include "pseries.h"

@@ -450,6 +451,40 @@ static void __init find_and_init_phbs(vo
of_pci_check_probe_only();
}

+static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
+{
+ if (result->character & H_CPU_CHAR_SPEC_BAR_ORI31)
+ security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
+
+ if (result->character & H_CPU_CHAR_BCCTRL_SERIALISED)
+ security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
+
+ if (result->character & H_CPU_CHAR_L1D_FLUSH_ORI30)
+ security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
+
+ if (result->character & H_CPU_CHAR_L1D_FLUSH_TRIG2)
+ security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
+
+ if (result->character & H_CPU_CHAR_L1D_THREAD_PRIV)
+ security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
+
+ if (result->character & H_CPU_CHAR_COUNT_CACHE_DISABLED)
+ security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
+
+ /*
+ * The features below are enabled by default, so we instead look to see
+ * if firmware has *disabled* them, and clear them if so.
+ */
+ if (!(result->character & H_CPU_BEHAV_FAVOUR_SECURITY))
+ security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
+
+ if (!(result->character & H_CPU_BEHAV_L1D_FLUSH_PR))
+ security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
+
+ if (!(result->character & H_CPU_BEHAV_BNDS_CHK_SPEC_BAR))
+ security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
+}
+
void pseries_setup_rfi_flush(void)
{
struct h_cpu_char_result result;
@@ -463,6 +498,8 @@ void pseries_setup_rfi_flush(void)

rc = plpar_get_cpu_characteristics(&result);
if (rc == H_SUCCESS) {
+ init_cpu_char_feature_flags(&result);
+
if (result.character & H_CPU_CHAR_L1D_FLUSH_TRIG2)
types |= L1D_FLUSH_MTTRIG;
if (result.character & H_CPU_CHAR_L1D_FLUSH_ORI30)
@@ -473,6 +510,12 @@ void pseries_setup_rfi_flush(void)
enable = false;
}

+ /*
+ * We're the guest so this doesn't apply to us, clear it to simplify
+ * handling of it elsewhere.
+ */
+ security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
+
setup_rfi_flush(types, enable);
}