The following commit has been merged into the x86/bugs branch of tip: Commit-ID: a48dc42614cad39fac1ef55d690847fd07f0e3c6 Gitweb: https://git.kernel.org/tip/a48dc42614cad39fac1ef55d690847fd07f0e3c6 Author: Yosry Ahmed <yosry.ahmed@xxxxxxxxx> AuthorDate: Thu, 27 Feb 2025 01:27:08 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Thu, 27 Feb 2025 10:57:20 +01:00 x86/mm: Remove X86_FEATURE_USE_IBPB checks in cond_mitigation() 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@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Link: https://lore.kernel.org/r/20250227012712.3193063-3-yosry.ahmed@xxxxxxxxx --- arch/x86/mm/tlb.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 4f61d11..3070807 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(); }
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