Commit 54b53dca authored by David Kaplan's avatar David Kaplan Committed by Borislav Petkov (AMD)
Browse files

x86/bugs: Add attack vector controls for RFDS 



Use attack vector controls to determine if RFDS 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/20250707183316.1349127-9-david.kaplan@amd.com
parent de6f0921

arch/x86/kernel/cpu/bugs.c

+8 −4
Original line number Diff line number Diff line
@@ -748,13 +748,17 @@ static inline bool __init verw_clears_cpu_reg_file(void) 


static void __init rfds_select_mitigation(void)

{

	if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) {

	if (!boot_cpu_has_bug(X86_BUG_RFDS)) {

		rfds_mitigation = RFDS_MITIGATION_OFF;

		return;

	}



	if (rfds_mitigation == RFDS_MITIGATION_AUTO)

	if (rfds_mitigation == RFDS_MITIGATION_AUTO) {

		if (should_mitigate_vuln(X86_BUG_RFDS))

			rfds_mitigation = RFDS_MITIGATION_VERW;

		else

			rfds_mitigation = RFDS_MITIGATION_OFF;

	}



	if (rfds_mitigation == RFDS_MITIGATION_OFF)

		return;
@@ -765,7 +769,7 @@ static void __init rfds_select_mitigation(void) 


static void __init rfds_update_mitigation(void)

{

	if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off())

	if (!boot_cpu_has_bug(X86_BUG_RFDS))

		return;



	if (verw_clear_cpu_buf_mitigation_selected)