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authorMauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>2018-03-30 14:28:25 -0300
committerMichael Ellerman <mpe@ellerman.id.au>2018-04-03 21:50:09 +1000
commit6232774f1599028a15418179d17f7df47ede770a (patch)
treec6b45aeb43b9830ac9717df5d84deeb55c29ca01 /arch/powerpc/platforms/pseries
parente7347a86830f38dc3e40c8f7e28c04412b12a2e7 (diff)
powerpc/pseries: Restore default security feature flags on setup
After migration the security feature flags might have changed (e.g., destination system with unpatched firmware), but some flags are not set/clear again in init_cpu_char_feature_flags() because it assumes the security flags to be the defaults. Additionally, if the H_GET_CPU_CHARACTERISTICS hypercall fails then init_cpu_char_feature_flags() does not run again, which potentially might leave the system in an insecure or sub-optimal configuration. So, just restore the security feature flags to the defaults assumed by init_cpu_char_feature_flags() so it can set/clear them correctly, and to ensure safe settings are in place in case the hypercall fail. Fixes: f636c14790ea ("powerpc/pseries: Set or clear security feature flags") Depends-on: 19887d6a28e2 ("powerpc: Move default security feature flags") Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/pseries')
-rw-r--r--arch/powerpc/platforms/pseries/setup.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 98bca8d9c9e0..b55ad4286dc7 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -462,6 +462,10 @@ static void __init find_and_init_phbs(void)
static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
{
+ /*
+ * The features below are disabled by default, so we instead look to see
+ * if firmware has *enabled* them, and set them if so.
+ */
if (result->character & H_CPU_CHAR_SPEC_BAR_ORI31)
security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
@@ -501,6 +505,13 @@ void pseries_setup_rfi_flush(void)
bool enable;
long rc;
+ /*
+ * Set features to the defaults assumed by init_cpu_char_feature_flags()
+ * so it can set/clear again any features that might have changed after
+ * migration, and in case the hypercall fails and it is not even called.
+ */
+ powerpc_security_features = SEC_FTR_DEFAULT;
+
rc = plpar_get_cpu_characteristics(&result);
if (rc == H_SUCCESS)
init_cpu_char_feature_flags(&result);