From: Josh Poimboeuf jpoimboe@kernel.org
commit 1dc6ff02c8bf77d71b9b5d11cbc9df77cfb28626 upstream
Similar to MDS and TAA, print a warning if SMT is enabled for the MMIO Stale Data vulnerability.
Signed-off-by: Josh Poimboeuf jpoimboe@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@canonical.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/cpu/bugs.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1214,6 +1214,7 @@ static void update_mds_branch_idle(void)
#define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n" #define TAA_MSG_SMT "TAA CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.h... for more details.\n" +#define MMIO_MSG_SMT "MMIO Stale Data CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/processor_mmio_st... for more details.\n"
void arch_smt_update(void) { @@ -1258,6 +1259,16 @@ void arch_smt_update(void) break; }
+ switch (mmio_mitigation) { + case MMIO_MITIGATION_VERW: + case MMIO_MITIGATION_UCODE_NEEDED: + if (sched_smt_active()) + pr_warn_once(MMIO_MSG_SMT); + break; + case MMIO_MITIGATION_OFF: + break; + } + mutex_unlock(&spec_ctrl_mutex); }