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Commit 71078b82 authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Greg Kroah-Hartman
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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: 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>
parent da06c60d

arch/x86/kernel/cpu/bugs.c

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

{
@@ -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);

}