Messages in this thread |  | | Subject | Re: [tip:x86/urgent] x86-64, build: Always pass in -mno-sse | From | "H. Peter Anvin" <> | Date | Wed, 04 Dec 2013 07:31:28 -0800 |
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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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