x86/bugs: Remove the X86_FEATURE_USE_IBPB check in ib_prctl_set()

If X86_FEATURE_USE_IBPB is not set, then both spectre_v2_user_ibpb and
spectre_v2_user_stibp are set to SPECTRE_V2_USER_NONE in
spectre_v2_user_select_mitigation(). Since ib_prctl_set() already checks
for this before performing the IBPB, the X86_FEATURE_USE_IBPB check is
redundant. Remove it.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20250227012712.3193063-4-yosry.ahmed@linux.dev

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 754150fc05784e539c0592dfe2f48d4a3ed3f4c2..1d7afc40f2272bcf2838f466dcc6254d522eab1a 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2272,7 +2272,7 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl)
                if (ctrl == PR_SPEC_FORCE_DISABLE)
                        task_set_spec_ib_force_disable(task);
                task_update_spec_tif(task);
-               if (task == current && cpu_feature_enabled(X86_FEATURE_USE_IBPB))
+               if (task == current)
                        indirect_branch_prediction_barrier();
                break;
        default: