From c6fd893da927c6cefb2ece22402765379921a834 Mon Sep 17 00:00:00 2001
From: Suresh Siddha <suresh.b.siddha@intel.com>
Date: Tue, 31 Jul 2012 10:29:14 -0700
Subject: [PATCH] x86, avx: don't use avx instructions with "noxsave" boot
param
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
Cc: <stable@vger.kernel.org> # v3.5
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
arch/x86/kernel/cpu/common.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 46d8786d655e..a5fbc3c5fccc 100644
--- 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);
--
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