The following commit has been merged into the x86/bugs branch of tip:
Commit-ID: 2a08b832712980b9eb0e913d64a42c74fc56319b
Gitweb: https://git.kernel.org/tip/2a08b832712980b9eb0e913d64a42c74fc56319b
Author: Breno Leitao <leitao@xxxxxxxxxx>
AuthorDate: Thu, 31 Oct 2024 04:06:16 -07:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 03 Mar 2025 12:48:17 +01:00
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: Breno Leitao <leitao@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
Cc: David Kaplan <David.Kaplan@xxxxxxx>
Link: https://lore.kernel.org/r/20241031-x86_bugs_last_v2-v2-1-b7ff1dab840e@xxxxxxxxxx
---
arch/x86/kernel/cpu/bugs.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 93c437f..346bebf 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -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;
|