commit
e2c3c94788b08891dcf3dbe608f9880523ecd71b upstream
This code is only for CPUs which are affected by MSBDS, but are *not*
affected by the other two MDS issues.
For such CPUs, enabling the mds_idle_clear mitigation is enough to
mitigate SMT.
However if user boots with 'mds=off' and still has SMT enabled, we should
not report that SMT is mitigated:
$cat /sys//devices/system/cpu/vulnerabilities/mds
Vulnerable; SMT mitigated
But rather:
Vulnerable; SMT vulnerable
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20190412215118.294906495@localhost.localdomain
(cherry picked from commit
31203de125c7e160bcb42927a5db0bf01de98f6a)
Orabug:
29526900
CVE: CVE-2018-12126
CVE: CVE-2018-12130
CVE: CVE-2018-12127
Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Conflicts:
arch/x86/kernel/cpu/bugs.c
bugs.c vs bug_64.c in UEK4
if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) {
return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
- (cpu_smt_control == CPU_SMT_ENABLED) ? "mitigated" : "disabled");
+ (mds_mitigation == MDS_MITIGATION_OFF ? "vulnerable" :
+ (cpu_smt_control == CPU_SMT_ENABLED ? "mitigated" : "disabled")));
}
return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],