From: Konrad Rzeszutek Wilk Date: Fri, 12 Apr 2019 21:50:58 +0000 (-0400) Subject: x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off X-Git-Tag: v5.2-rc1~75^2~5 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=e2c3c94788b08891dcf3dbe608f9880523ecd71b;p=linux.git x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off 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 Signed-off-by: Thomas Gleixner Reviewed-by: Tyler Hicks Reviewed-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20190412215118.294906495@localhost.localdomain --- diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 0642505dda69..6b8a55c7cebc 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1204,7 +1204,8 @@ static ssize_t mds_show_state(char *buf) if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) { return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation], - sched_smt_active() ? "mitigated" : "disabled"); + (mds_mitigation == MDS_MITIGATION_OFF ? "vulnerable" : + sched_smt_active() ? "mitigated" : "disabled")); } return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],