From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 13 Oct 2017 14:56:45 -0700 Subject: [PATCH] x86/fpu: Remove the explicit clearing of XSAVE dependent features MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CVE-2017-5754 Clearing a CPU feature with setup_clear_cpu_cap() clears all features which depend on it. Expressing feature dependencies in one place is easier to maintain than keeping functions like fpu__xstate_clear_all_cpu_caps() up to date. The features which depend on XSAVE have their dependency expressed in the dependency table, so its sufficient to clear X86_FEATURE_XSAVE. Remove the explicit clearing of XSAVE dependent features. Signed-off-by: Andi Kleen Reviewed-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171013215645.23166-6-andi@firstfloor.org Signed-off-by: Ingo Molnar (cherry picked from commit 73e3a7d2a7c3be29a5a22b85026f6cfa5664267f) Signed-off-by: Andy Whitcroft Signed-off-by: Kleber Sacilotto de Souza (cherry picked from commit af445f9ba8bb30b47ccb5247b8f5ba28c9f2be3e) Signed-off-by: Fabian Grünbichler --- arch/x86/kernel/fpu/xstate.c | 20 -------------------- 1 file changed, 20 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 3abe85b08234..fd6882c42246 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -73,26 +73,6 @@ unsigned int fpu_user_xstate_size; void fpu__xstate_clear_all_cpu_caps(void) { setup_clear_cpu_cap(X86_FEATURE_XSAVE); - setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); - setup_clear_cpu_cap(X86_FEATURE_XSAVEC); - setup_clear_cpu_cap(X86_FEATURE_XSAVES); - setup_clear_cpu_cap(X86_FEATURE_AVX); - setup_clear_cpu_cap(X86_FEATURE_AVX2); - setup_clear_cpu_cap(X86_FEATURE_AVX512F); - setup_clear_cpu_cap(X86_FEATURE_AVX512IFMA); - setup_clear_cpu_cap(X86_FEATURE_AVX512PF); - setup_clear_cpu_cap(X86_FEATURE_AVX512ER); - setup_clear_cpu_cap(X86_FEATURE_AVX512CD); - setup_clear_cpu_cap(X86_FEATURE_AVX512DQ); - setup_clear_cpu_cap(X86_FEATURE_AVX512BW); - setup_clear_cpu_cap(X86_FEATURE_AVX512VL); - setup_clear_cpu_cap(X86_FEATURE_MPX); - setup_clear_cpu_cap(X86_FEATURE_XGETBV1); - setup_clear_cpu_cap(X86_FEATURE_AVX512VBMI); - setup_clear_cpu_cap(X86_FEATURE_PKU); - setup_clear_cpu_cap(X86_FEATURE_AVX512_4VNNIW); - setup_clear_cpu_cap(X86_FEATURE_AVX512_4FMAPS); - setup_clear_cpu_cap(X86_FEATURE_AVX512_VPOPCNTDQ); } /* -- 2.14.2