From 7e44909e0ea8346ba08b244ecc275fc3394e2b8e Mon Sep 17 00:00:00 2001 From: Pawan Gupta Date: Wed, 11 Jun 2025 10:29:47 -0700 Subject: [PATCH] x86/bugs: Use switch/case in its_apply_mitigation() Prepare to apply stuffing mitigation in its_apply_mitigation(). This is currently only done via retbleed mitigation. Also using switch/case makes it evident that mitigation mode like VMEXIT_ONLY doesn't need any special handling. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Nikolay Borisov Link: https://lore.kernel.org/20250611-eibrs-fix-v4-4-5ff86cac6c61@linux.intel.com --- arch/x86/kernel/cpu/bugs.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 20696abd1bef..e861e8884d6b 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1468,15 +1468,21 @@ static void __init its_update_mitigation(void) static void __init its_apply_mitigation(void) { + switch (its_mitigation) { + case ITS_MITIGATION_OFF: + case ITS_MITIGATION_AUTO: + case ITS_MITIGATION_VMEXIT_ONLY: /* its=stuff forces retbleed stuffing and is enabled there. */ - if (its_mitigation != ITS_MITIGATION_ALIGNED_THUNKS) - return; - - if (!boot_cpu_has(X86_FEATURE_RETPOLINE)) - setup_force_cpu_cap(X86_FEATURE_INDIRECT_THUNK_ITS); + case ITS_MITIGATION_RETPOLINE_STUFF: + break; + case ITS_MITIGATION_ALIGNED_THUNKS: + if (!boot_cpu_has(X86_FEATURE_RETPOLINE)) + setup_force_cpu_cap(X86_FEATURE_INDIRECT_THUNK_ITS); - setup_force_cpu_cap(X86_FEATURE_RETHUNK); - set_return_thunk(its_return_thunk); + setup_force_cpu_cap(X86_FEATURE_RETHUNK); + set_return_thunk(its_return_thunk); + break; + } } #undef pr_fmt -- 2.25.1