Commit 6d8e8ddf authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Yongqiang Liu
Browse files

x86/speculation/mmio: Print SMT warning 

stable inclusion
from stable-v4.19.248
commit 0255c936bfaa1887f7043b995f1c9e1049bb25f1
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5D5RS


CVE: CVE-2022-21123,CVE-2022-21125,CVE-2022-21166

--------------------------------

commit 1dc6ff02 upstream

Similar to MDS and TAA, print a warning if SMT is enabled for the MMIO
Stale Data vulnerability.

Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarYipeng Zou <zouyipeng@huawei.com>
Reviewed-by: default avatarZhang Jianhua <chris.zjh@huawei.com>
Reviewed-by: default avatarLiao Chang <liaochang1@huawei.com>
Signed-off-by: default avatarYongqiang Liu <liuyongqiang13@huawei.com>
parent 4c9a908c

arch/x86/kernel/cpu/bugs.c

+11 −0
Original line number Diff line number Diff line
@@ -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);

}