[3.8.y.z extended stable] Patch "x86-64, build: Always pass in -mno-sse" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    x86-64, build: Always pass in -mno-sse

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.15.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 10eef745f9a1c2166b028852f3bd6ecaad23edbd Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa at linux.intel.com>
Date: Wed, 20 Nov 2013 13:31:49 -0800
Subject: x86-64, build: Always pass in -mno-sse

commit 5551a34e5aeab868f8d37f70d8754868921b4ee5 upstream.

Always pass in the -mno-sse argument, regardless if
-preferred-stack-boundary is supported.  We never want to generate SSE
instructions in the kernel unless we *really* know what we're doing.

According to H. J. Lu, any version of gcc new enough that we support
it at all should handle the -mno-sse option, so just add it
unconditionally.

Reported-by: Kevin B. Smith <kevin.b.smith at intel.com>
Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
Cc: H. J. Lu <hjl.tools at gmail.com>
Link: http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/x86/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index e71fc42..8c2ad4e 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -27,6 +27,9 @@ ifeq ($(CONFIG_X86_32),y)

         KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return

+        # Don't autogenerate SSE instructions
+	KBUILD_CFLAGS += -mno-sse
+
         # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
         # with nonstandard options
         KBUILD_CFLAGS += -fno-pic
@@ -53,8 +56,11 @@ else
         KBUILD_AFLAGS += -m64
         KBUILD_CFLAGS += -m64

+        # Don't autogenerate SSE instructions
+	KBUILD_CFLAGS += -mno-sse
+
 	# Use -mpreferred-stack-boundary=3 if supported.
-	KBUILD_CFLAGS += $(call cc-option,-mno-sse -mpreferred-stack-boundary=3)
+	KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)

         # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
         cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
--
1.8.3.2