Re: [PATCH v3 30/35] x86/bugs: Add attack vector controls for spectre_v2_user

[Josh Poimboeuf]

On Wed, Jan 08, 2025 at 02:25:10PM -0600, David Kaplan wrote:
> @@ -1614,6 +1614,13 @@ spectre_v2_user_select_mitigation(void)
>  		spectre_v2_user_stibp = SPECTRE_V2_USER_STRICT;
>  		break;
>  	case SPECTRE_V2_USER_CMD_AUTO:
> +		if (should_mitigate_vuln(X86_BUG_SPECTRE_V2_USER)) {
> +			spectre_v2_user_ibpb = SPECTRE_V2_USER_PRCTL;
> +			spectre_v2_user_stibp = SPECTRE_V2_USER_PRCTL;
> +		} else {
> +			return;
> +		}
> +		break;

Can just fallthrough in the should_mitigate_vuln() case?

>  	case SPECTRE_V2_USER_CMD_PRCTL:
>  		spectre_v2_user_ibpb = SPECTRE_V2_USER_PRCTL;
>  		spectre_v2_user_stibp = SPECTRE_V2_USER_PRCTL;

-- 
Josh