Commit 530e8064 authored by Pawan Gupta's avatar Pawan Gupta Committed by Borislav Petkov (AMD)
Browse files

x86/bugs: Simplify the retbleed=stuff checks 



Simplify the nested checks, remove redundant print and comment.

Signed-off-by: default avatarPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarNikolay Borisov <nik.borisov@suse.com>
Acked-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250611-eibrs-fix-v4-2-5ff86cac6c61@linux.intel.com
parent 98ff5c07

arch/x86/kernel/cpu/bugs.c

+8 −16
Original line number Diff line number Diff line
@@ -1263,24 +1263,16 @@ static void __init retbleed_update_mitigation(void) 
	if (!boot_cpu_has_bug(X86_BUG_RETBLEED) || cpu_mitigations_off())

		return;



	/*

	 * retbleed=stuff is only allowed on Intel.  If stuffing can't be used

	 * then a different mitigation will be selected below.

	 *

	 * its=stuff will also attempt to enable stuffing.

	 */

	if (retbleed_mitigation == RETBLEED_MITIGATION_STUFF ||

	    its_mitigation == ITS_MITIGATION_RETPOLINE_STUFF) {

		if (spectre_v2_enabled != SPECTRE_V2_RETPOLINE) {

	 /* ITS can also enable stuffing */

	if (its_mitigation == ITS_MITIGATION_RETPOLINE_STUFF)

		retbleed_mitigation = RETBLEED_MITIGATION_STUFF;



	if (retbleed_mitigation == RETBLEED_MITIGATION_STUFF &&

	    spectre_v2_enabled != SPECTRE_V2_RETPOLINE) {

		pr_err("WARNING: retbleed=stuff depends on spectre_v2=retpoline\n");

		retbleed_mitigation = RETBLEED_MITIGATION_NONE;

		} else {

			if (retbleed_mitigation != RETBLEED_MITIGATION_STUFF)

				pr_info("Retbleed mitigation updated to stuffing\n");



			retbleed_mitigation = RETBLEED_MITIGATION_STUFF;

		}

	}



	/*

	 * Let IBRS trump all on Intel without affecting the effects of the

	 * retbleed= cmdline option except for call depth based stuffing