From: Josh Poimboeuf Date: Mon, 23 May 2022 16:11:49 +0000 (-0700) Subject: x86/speculation/mmio: Print SMT warning X-Git-Tag: v4.19.248~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0255c936bfaa1887f7043b995f1c9e1049bb25f1;p=thirdparty%2Fkernel%2Fstable.git x86/speculation/mmio: Print SMT warning 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 Signed-off-by: Thomas Gleixner Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index c37ea8598c34f..058e92b932623 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1215,6 +1215,7 @@ 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.html 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_stale_data.html for more details.\n" void arch_smt_update(void) { @@ -1259,6 +1260,16 @@ 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); }