Commit 2a08b832 authored by Breno Leitao's avatar Breno Leitao Committed by Ingo Molnar
Browse files

x86/bugs: Use the cpu_smt_possible() helper instead of open-coded code 



There is a helper function to check if SMT is available. Use this helper
instead of performing the check manually.

The helper function cpu_smt_possible() does exactly the same thing as
was being done manually inside spectre_v2_user_select_mitigation().
Specifically, it returns false if CONFIG_SMP is disabled, otherwise
it checks the cpu_smt_control global variable.

This change improves code consistency and reduces duplication.

No change in functionality intended.

Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: David Kaplan <David.Kaplan@amd.com>
Link: https://lore.kernel.org/r/20241031-x86_bugs_last_v2-v2-1-b7ff1dab840e@debian.org
parent b8ce25df

arch/x86/kernel/cpu/bugs.c

+1 −6
Original line number Diff line number Diff line
@@ -1346,16 +1346,11 @@ static void __init 
spectre_v2_user_select_mitigation(void)

{

	enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE;

	bool smt_possible = IS_ENABLED(CONFIG_SMP);

	enum spectre_v2_user_cmd cmd;



	if (!boot_cpu_has(X86_FEATURE_IBPB) && !boot_cpu_has(X86_FEATURE_STIBP))

		return;



	if (cpu_smt_control == CPU_SMT_FORCE_DISABLED ||

	    cpu_smt_control == CPU_SMT_NOT_SUPPORTED)

		smt_possible = false;



	cmd = spectre_v2_parse_user_cmdline();

	switch (cmd) {

	case SPECTRE_V2_USER_CMD_NONE:
@@ -1416,7 +1411,7 @@ spectre_v2_user_select_mitigation(void) 
	 * so allow for STIBP to be selected in those cases.

	 */

	if (!boot_cpu_has(X86_FEATURE_STIBP) ||

	    !smt_possible ||

	    !cpu_smt_possible() ||

	    (spectre_v2_in_eibrs_mode(spectre_v2_enabled) &&

	     !boot_cpu_has(X86_FEATURE_AUTOIBRS)))

		return;