diff mbox series

[v2,2/6] x86/mm: Remove X86_FEATURE_USE_IBPB checks in cond_mitigation()

Message ID 20250227012712.3193063-3-yosry.ahmed@linux.dev (mailing list archive)
State New
Headers show
Series IBPB cleanups and a fixup | expand

Commit Message

Yosry Ahmed Feb. 27, 2025, 1:27 a.m. UTC 
The check is performed when either switch_mm_cond_ibpb or
switch_mm_always_ibpb is set. In both cases, X86_FEATURE_USE_IBPB is
always set. Remove the redundant check.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 arch/x86/mm/tlb.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index be0c1a509869c..e860fc8edfae4 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -437,8 +437,7 @@  static void cond_mitigation(struct task_struct *next)
 		 * both have the IBPB bit set.
 		 */
 		if (next_mm != prev_mm &&
-		    (next_mm | prev_mm) & LAST_USER_MM_IBPB &&
-		    cpu_feature_enabled(X86_FEATURE_USE_IBPB))
+		    (next_mm | prev_mm) & LAST_USER_MM_IBPB)
 			indirect_branch_prediction_barrier();
 	}
 
@@ -448,8 +447,7 @@  static void cond_mitigation(struct task_struct *next)
 		 * different context than the user space task which ran
 		 * last on this CPU.
 		 */
-		if ((prev_mm & ~LAST_USER_MM_SPEC_MASK) != (unsigned long)next->mm &&
-		    cpu_feature_enabled(X86_FEATURE_USE_IBPB))
+		if ((prev_mm & ~LAST_USER_MM_SPEC_MASK) != (unsigned long)next->mm)
 			indirect_branch_prediction_barrier();
 	}