There is a lot of variation in the Arm ecosystem. Because of this, there exist possible cases where the kernel cannot authoritatively determine if a machine is vulnerable.
Rather than guess the vulnerability status in cases where the mitigation is disabled or the firmware isn't responding correctly, we need to display an "Unknown" state. Signed-off-by: Jeremy Linton <jeremy.lin...@arm.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Dave Hansen <dave.han...@intel.com> Cc: Borislav Petkov <b...@alien8.de> Cc: David Woodhouse <d...@amazon.co.uk> --- Documentation/ABI/testing/sysfs-devices-system-cpu | 1 + 1 file changed, 1 insertion(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 9605dbd4b5b5..876103fddfa4 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -495,6 +495,7 @@ Description: Information about CPU vulnerabilities "Not affected" CPU is not affected by the vulnerability "Vulnerable" CPU is affected and no mitigation in effect "Mitigation: $M" CPU is affected and mitigation $M is in effect + "Unknown" The kernel is unable to make a determination Details about the l1tf file can be found in Documentation/admin-guide/l1tf.rst -- 2.17.2