3.16.68-rc1 review patch. If anyone has any objections, please let me know.
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From: Josh Poimboeuf jpoimboe@redhat.com
commit 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 upstream.
Add MDS to the new 'mitigations=' cmdline option.
Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Signed-off-by: Thomas Gleixner tglx@linutronix.de [bwh: Backported to 3.16: - Drop the auto,nosmt option, which we can't support - Adjust filenames, context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1920,6 +1920,7 @@ bytes respectively. Such letter suffixes nospectre_v2 [X86] spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86] + mds=off [X86]
auto (default) Mitigate all CPU vulnerabilities, but leave SMT --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -287,7 +287,7 @@ static const char * const mds_strings[]
static void __init mds_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_MDS)) { + if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off()) { mds_mitigation = MDS_MITIGATION_OFF; return; }