[x86_64] Cherrypick gcc-10 fix.
Cherry-pick the upstream commit df6d4f9db79c1a5d6f48b59db35ccd1e9ff9adfc
allowing the build to succeed on gcc 10.
x86/boot/compressed: Don't declare __force_order in kaslr_64.c
GCC 10 changed the default to -fno-common, which leads to
LD arch/x86/boot/compressed/vmlinux
ld: arch/x86/boot/compressed/pgtable_64.o:(.bss+0x0): multiple definition of `__force_order'; \
arch/x86/boot/compressed/kaslr_64.o:(.bss+0x0): first defined here
make[2]: *** [arch/x86/boot/compressed/Makefile:119: arch/x86/boot/compressed/vmlinux] Error 1
Since __force_order is already provided in pgtable_64.c, there is no
need to declare __force_order in kaslr_64.c.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200124181811.4780-1-hjl.tools@gmail.com
Change-Id: I913cd40729d9633c1f71f3b71af3cc45fbc7606c
diff --git a/arch/x86/boot/compressed/kaslr_64.c b/arch/x86/boot/compressed/kaslr_64.c
index 748456c..9557c5a 100644
--- a/arch/x86/boot/compressed/kaslr_64.c
+++ b/arch/x86/boot/compressed/kaslr_64.c
@@ -29,9 +29,6 @@
#define __PAGE_OFFSET __PAGE_OFFSET_BASE
#include "../../mm/ident_map.c"
-/* Used by pgtable.h asm code to force instruction serialization. */
-unsigned long __force_order;
-
/* Used to track our page table allocation area. */
struct alloc_pgt_data {
unsigned char *pgt_buf;
