[Xen-changelog] [xen master] Revert "x86/EFI: meet further spec requirements for runtime calls"

[patchbot@xxxxxxx]

commit d4e202c39f0e464dfcec0e28f56725d516e190c6
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Mon Nov 14 08:53:16 2016 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Nov 14 08:53:16 2016 +0100

    Revert "x86/EFI: meet further spec requirements for runtime calls"
    
    This reverts commit 67b5b302f5319f70288587dc98ab505c4deada1e as
    being both actively wrong and latently broken.
---
 xen/arch/x86/efi/Makefile |  5 -----
 xen/common/efi/runtime.c  | 16 +---------------
 2 files changed, 1 insertion(+), 20 deletions(-)

diff --git a/xen/arch/x86/efi/Makefile b/xen/arch/x86/efi/Makefile
index 7a743f8..ad3fdf7 100644
--- a/xen/arch/x86/efi/Makefile
+++ b/xen/arch/x86/efi/Makefile
@@ -14,10 +14,5 @@ extra-$(efi) += boot.init.o relocs-dummy.o runtime.o 
compat.o buildid.o
 %.o: %.ihex
        $(OBJCOPY) -I ihex -O binary $< $@
 
-cc-runtime.o := $(CC) -mno-sse
-$(call 
cc-option-add,cflags-runtime.o,cc-runtime.o,-mpreferred-stack-boundary=3)
-$(call cc-option-add,cflags-runtime.o,cc-runtime.o,-mincoming-stack-boundary=3)
-runtime.o: CFLAGS += $(cflags-runtime.o)
-
 stub.o: $(extra-y)
 nogcov-$(efi) += stub.o
diff --git a/xen/common/efi/runtime.c b/xen/common/efi/runtime.c
index 926dae6..c256814 100644
--- a/xen/common/efi/runtime.c
+++ b/xen/common/efi/runtime.c
@@ -59,26 +59,12 @@ unsigned long efi_rs_enter(void)
     static const u16 fcw = FCW_DEFAULT;
     static const u32 mxcsr = MXCSR_DEFAULT;
     unsigned long cr3 = read_cr3();
-#if __GNUC__ < 5 || (__GNUC__ == 5 && __GNUC_MINOR__ < 3)
-/*
- * -mpreferred-stack-boundary=3 is can be used only from gcc 4.8 onwards,
- * and -mincoming-stack-boundary=3 only from 5.3 onwards. Therefore higher
- * than necessary alignment is being forced here in that case.
- */
-# define FORCE_ALIGN 32
-#else
-# define FORCE_ALIGN 16
-#endif
-    unsigned long __aligned(FORCE_ALIGN) placeholder[0];
-#undef FORCE_ALIGN
-
-    asm volatile("" : "+m" (placeholder));
 
     if ( !efi_l4_pgtable )
         return 0;
 
     save_fpu_enable();
-    asm volatile ( "fnclex; fldcw %0" :: "m" (fcw) );
+    asm volatile ( "fldcw %0" :: "m" (fcw) );
     asm volatile ( "ldmxcsr %0" :: "m" (mxcsr) );
 
     spin_lock(&efi_rs_lock);
--
generated by git-patchbot for /home/xen/git/xen.git#master

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