x86, avx: don't use avx instructions with "noxsave" boot param

commit c6fd893da927c6cefb2ece22402765379921a834 upstream.

Clear AVX, AVX2 features along with clearing XSAVE feature bits,
as part of the parsing "noxsave" parameter.

Fixes the kernel boot panic with "noxsave" boot parameter.

We could have checked cpu_has_osxsave along with cpu_has_avx etc, but Peter
mentioned clearing the feature bits will be better for uses like
static_cpu_has() etc.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1343755754.2041.2.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 6b9333b429ba1910637bf29c63bbe0712064022e..cc9c146c584550c8e89b399fefacb7ddb52567c1 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -144,6 +144,8 @@ static int __init x86_xsave_setup(char *s)
 {
        setup_clear_cpu_cap(X86_FEATURE_XSAVE);
        setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
+       setup_clear_cpu_cap(X86_FEATURE_AVX);
+       setup_clear_cpu_cap(X86_FEATURE_AVX2);
        return 1;
 }
 __setup("noxsave", x86_xsave_setup);