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    SubjectRe: [tip:x86/urgent] x86-64, build: Always pass in -mno-sse
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    I can regenerate the patch if you want.

    Ingo Molnar <mingo@kernel.org> wrote:
    >
    >* tip-bot for H. Peter Anvin <tipbot@zytor.com> wrote:
    >
    >> Commit-ID: 5551a34e5aeab868f8d37f70d8754868921b4ee5
    >> Gitweb:
    >http://git.kernel.org/tip/5551a34e5aeab868f8d37f70d8754868921b4ee5
    >> Author: H. Peter Anvin <hpa@linux.intel.com>
    >> AuthorDate: Wed, 20 Nov 2013 13:31:49 -0800
    >> Committer: H. Peter Anvin <hpa@linux.intel.com>
    >> CommitDate: Tue, 3 Dec 2013 17:40:22 -0800
    >>
    >> x86-64, build: Always pass in -mno-sse
    >>
    >> 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@intel.com>
    >> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
    >> Cc: H. J. Lu <hjl.tools@gmail.com>
    >> Link:
    >http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org
    >> Cc: <stable@vger.kernel.org> # build fix only
    >> ---
    >> arch/x86/Makefile | 8 +++++++-
    >> 1 file changed, 7 insertions(+), 1 deletion(-)
    >>
    >> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
    >> index 41250fb..eda00f9 100644
    >> --- a/arch/x86/Makefile
    >> +++ b/arch/x86/Makefile
    >> @@ -31,6 +31,9 @@ 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
    >> @@ -57,8 +60,11 @@ 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)
    >
    >Just a detail I noticed: in kbuild we intentionally use 8 spaces for
    >tabs in Makefiles and only use tabs for commands where tabs are
    >required.
    >
    >The above code introduces tabs in the middle of 8-space sequences. It
    >works but is inconsistent.
    >
    >Thanks,
    >
    > Ingo

    --
    Sent from my mobile phone. Please pardon brevity and lack of formatting.


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