4.9-stable review patch. If anyone has any objections, please let me know.
------------------
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); }