On 06/12/2018 23:44, Jeremy Linton wrote: > Add code to track whether all the cores in the machine are > vulnerable, and whether all the vulnerable cores have been > mitigated. > > Once we have that information we can add the sysfs stub and > provide an accurate view of what is known about the machine. > > Signed-off-by: Jeremy Linton <[email protected]> > --- > arch/arm64/kernel/cpu_errata.c | 72 +++++++++++++++++++++++++++++++--- > 1 file changed, 67 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c > index 559ecdee6fd2..6505c93d507e 100644 > --- a/arch/arm64/kernel/cpu_errata.c > +++ b/arch/arm64/kernel/cpu_errata.c [...] > @@ -766,4 +812,20 @@ ssize_t cpu_show_spectre_v1(struct device *dev, struct > device_attribute *attr, > return sprintf(buf, "Mitigation: __user pointer sanitization\n"); > } > > +ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute > *attr, > + char *buf) > +{ > + switch (__spectrev2_safe) { > + case A64_SV2_SAFE: > + return sprintf(buf, "Not affected\n"); > + case A64_SV2_UNSAFE: > + if (__hardenbp_enab == A64_HBP_MIT) > + return sprintf(buf, > + "Mitigation: Branch predictor hardening\n"); > + return sprintf(buf, "Vulnerable\n"); > + default: > + return sprintf(buf, "Unknown\n"); > + } Again I see that we are going to display "Unknown" when the mitigation is not built in. Couldn't we make that CONFIG_GENERIC_CPU_VULNERABILITIES check whether a CPU is vulnerable or not even if the mitigation is not implemented? It's just checking the list of MIDRs. Thanks, -- Julien Thierry
