Commit eda718fd authored by David Kaplan's avatar David Kaplan Committed by Borislav Petkov (AMD)
Browse files

x86/bugs: Add attack vector controls for SRSO 



Use attack vector controls to determine if SRSO 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/20250707183316.1349127-18-david.kaplan@amd.com
parent 2f970a52

arch/x86/kernel/cpu/bugs.c

+10 −5
Original line number Diff line number Diff line
@@ -3123,14 +3123,19 @@ early_param("spec_rstack_overflow", srso_parse_cmdline); 


static void __init srso_select_mitigation(void)

{

	if (!boot_cpu_has_bug(X86_BUG_SRSO) || cpu_mitigations_off())

	if (!boot_cpu_has_bug(X86_BUG_SRSO)) {

		srso_mitigation = SRSO_MITIGATION_NONE;



	if (srso_mitigation == SRSO_MITIGATION_NONE)

		return;

	}



	if (srso_mitigation == SRSO_MITIGATION_AUTO)

	if (srso_mitigation == SRSO_MITIGATION_AUTO) {

		if (should_mitigate_vuln(X86_BUG_SRSO)) {

			srso_mitigation = SRSO_MITIGATION_SAFE_RET;

		} else {

			srso_mitigation = SRSO_MITIGATION_NONE;

			return;

		}

	}



	/* Zen1/2 with SMT off aren't vulnerable to SRSO. */

	if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) {