Messages in this thread | | | Date | Fri, 12 Jan 2018 23:13:13 +0100 | From | Dominik Brodowski <> | Subject | Re: [PATCH 1/4] x86/retpoline: Add new mode RETPOLINE_UNDERFLOW |
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> @@ -209,6 +234,11 @@ static void __init spectre_v2_select_mitigation(void) > mode = retp_compiler() ? SPECTRE_V2_RETPOLINE_GENERIC : > SPECTRE_V2_RETPOLINE_MINIMAL; > setup_force_cpu_cap(X86_FEATURE_RETPOLINE); > + if (mode == SPECTRE_V2_RETPOLINE_GENERIC && > + cpu_needs_underflow_protection()) { > + mode = SPECTRE_V2_RETPOLINE_UNDERFLOW; > + setup_force_cpu_cap(X86_FEATURE_RETURN_UNDERFLOW); > + } > }
Why does this require a retp-compatible compiler to be enabled?
Thanks, Dominik
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