Commit fdf99228 authored by David Kaplan's avatar David Kaplan Committed by Borislav Petkov (AMD)
Browse files

x86/bugs: Add attack vector controls for spectre_v2 



Use attack vector controls to determine if spectre_v2 mitigation is
required.

Signed-off-by: default avatarDavid Kaplan <david.kaplan@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250707183316.1349127-16-david.kaplan@amd.com
parent ddcd4d3c

arch/x86/kernel/cpu/bugs.c

+6 −4
Original line number Diff line number Diff line
@@ -2013,8 +2013,7 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) 
	int ret, i;



	cmd = IS_ENABLED(CONFIG_MITIGATION_SPECTRE_V2) ?  SPECTRE_V2_CMD_AUTO : SPECTRE_V2_CMD_NONE;

	if (cmdline_find_option_bool(boot_command_line, "nospectre_v2") ||

	    cpu_mitigations_off())

	if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))

		return SPECTRE_V2_CMD_NONE;



	ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg));
@@ -2286,8 +2285,11 @@ static void __init spectre_v2_select_mitigation(void) 
	case SPECTRE_V2_CMD_NONE:

		return;



	case SPECTRE_V2_CMD_FORCE:

	case SPECTRE_V2_CMD_AUTO:

		if (!should_mitigate_vuln(X86_BUG_SPECTRE_V2))

			break;

		fallthrough;

	case SPECTRE_V2_CMD_FORCE:

		if (boot_cpu_has(X86_FEATURE_IBRS_ENHANCED)) {

			spectre_v2_enabled = SPECTRE_V2_EIBRS;

			break;
@@ -2341,7 +2343,7 @@ static void __init spectre_v2_update_mitigation(void) 
		}

	}



	if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2) && !cpu_mitigations_off())

	if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2))

		pr_info("%s\n", spectre_v2_strings[spectre_v2_enabled]);

}