From: Andi Kleen <[email protected]> On 64bit we want to split X86_FEATURE_RETPOLINE and X86_FEATURE_RETPOLINE_AMD, so that only one is set. This enables new simpler ALTERNATIVE sequences.
But 32bit requires a common flag because it uses common code for both. So add a new X86_FEATURE_RETPOLINE_COMMON that is always set when either X86_FEATURE_RETPOLINE or X86_FEATURE_RETPOLINE_AMD are set. And then unset X86_FEATURE_RETPOLINE for AMD. Signed-off-by: Andi Kleen <[email protected]> --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/bugs.c | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index f275447862f4..54ec16ef08d8 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -211,6 +211,7 @@ #define X86_FEATURE_AVX512_4FMAPS ( 7*32+17) /* AVX-512 Multiply Accumulation Single precision */ #define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth Allocation */ +#define X86_FEATURE_RETPOLINE_COMMON ( 7*32+19) /* Common code for both RETPOLINE and RETPOLINE_AMD */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index b957f771a5b7..241eae66a86b 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -155,8 +155,10 @@ void __init spectre_v2_check_boottime_disable(void) retpoline_generic: spectre_v2_enabled = retp_compiler() ? SPECTRE_V2_RETPOLINE_GENERIC : SPECTRE_V2_RETPOLINE_MINIMAL; + setup_force_cpu_cap(X86_FEATURE_RETPOLINE); } - setup_force_cpu_cap(X86_FEATURE_RETPOLINE); + setup_force_cpu_cap(X86_FEATURE_RETPOLINE_COMMON); + return; #else retpoline: @@ -167,6 +169,7 @@ void __init spectre_v2_check_boottime_disable(void) disable: setup_clear_cpu_cap(X86_FEATURE_RETPOLINE); setup_clear_cpu_cap(X86_FEATURE_RETPOLINE_AMD); + setup_clear_cpu_cap(X86_FEATURE_RETPOLINE_COMMON); return; } -- 2.14.3
