4.16-stable review patch. If anyone has any objections, please let me know.
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From: Michael Ellerman mpe@ellerman.id.au
commit 77addf6e95c8689e478d607176b399a6242a777e upstream.
Now that we have feature flags for security related things, set or clear them based on what we see in the device tree provided by firmware.
Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/platforms/powernv/setup.c | 56 +++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)
--- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -38,9 +38,63 @@ #include <asm/smp.h> #include <asm/tm.h> #include <asm/setup.h> +#include <asm/security_features.h>
#include "powernv.h"
+ +static bool fw_feature_is(const char *state, const char *name, + struct device_node *fw_features) +{ + struct device_node *np; + bool rc = false; + + np = of_get_child_by_name(fw_features, name); + if (np) { + rc = of_property_read_bool(np, state); + of_node_put(np); + } + + return rc; +} + +static void init_fw_feat_flags(struct device_node *np) +{ + if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np)) + security_ftr_set(SEC_FTR_SPEC_BAR_ORI31); + + if (fw_feature_is("enabled", "fw-bcctrl-serialized", np)) + security_ftr_set(SEC_FTR_BCCTRL_SERIALISED); + + if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np)) + security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30); + + if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np)) + security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2); + + if (fw_feature_is("enabled", "fw-l1d-thread-split", np)) + security_ftr_set(SEC_FTR_L1D_THREAD_PRIV); + + if (fw_feature_is("enabled", "fw-count-cache-disabled", np)) + 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 (fw_feature_is("disabled", "speculation-policy-favor-security", np)) + security_ftr_clear(SEC_FTR_FAVOUR_SECURITY); + + if (fw_feature_is("disabled", "needs-l1d-flush-msr-pr-0-to-1", np)) + security_ftr_clear(SEC_FTR_L1D_FLUSH_PR); + + if (fw_feature_is("disabled", "needs-l1d-flush-msr-hv-1-to-0", np)) + security_ftr_clear(SEC_FTR_L1D_FLUSH_HV); + + if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np)) + security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR); +} + static void pnv_setup_rfi_flush(void) { struct device_node *np, *fw_features; @@ -56,6 +110,8 @@ static void pnv_setup_rfi_flush(void) of_node_put(np);
if (fw_features) { + init_fw_feat_flags(fw_features); + np = of_get_child_by_name(fw_features, "inst-l1d-flush-trig2"); if (np && of_property_read_bool(np, "enabled")) type = L1D_FLUSH_MTTRIG;