lkml.org 
[lkml]   [2012]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[ 174/262] x86, avx: dont use avx instructions with "noxsave" boot param
Date
From: Greg KH <gregkh@linuxfoundation.org>

3.5-stable review patch. If anyone has any objections, please let me know.

------------------

From: Suresh Siddha <suresh.b.siddha@intel.com>

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>

---
arch/x86/kernel/cpu/common.c | 2 ++
1 file changed, 2 insertions(+)

--- 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 *
{
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);



\
 
 \ /
  Last update: 2012-09-28 22:01    [W:0.954 / U:0.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site