From: Alexey Dobriyan adobriyan@gmail.com
commit b3bee1e7c3f2b1b77182302c7b2131c804175870 upstream.
Use -std=gnu11 for consistency with main kernel code.
It doesn't seem to change anything in vmlinux.
Signed-off-by: Alexey Dobriyan adobriyan@gmail.com Signed-off-by: Ingo Molnar mingo@kernel.org Acked-by: H. Peter Anvin (Intel) hpa@zytor.com Link: https://lore.kernel.org/r/2058761e-12a4-4b2f-9690-3c3c1c9902a5@p183 [ This kernel version doesn't build with GCC 15:
In file included from include/uapi/linux/posix_types.h:5, from include/uapi/linux/types.h:14, from include/linux/types.h:6, from arch/x86/realmode/rm/wakeup.h:11, from arch/x86/realmode/rm/wakemain.c:2: include/linux/stddef.h:11:9: error: cannot use keyword 'false' as enumeration constant 11 | false = 0, | ^~~~~ include/linux/stddef.h:11:9: note: 'false' is a keyword with '-std=c23' onwards include/linux/types.h:30:33: error: 'bool' cannot be defined via 'typedef' 30 | typedef _Bool bool; | ^~~~ include/linux/types.h:30:33: note: 'bool' is a keyword with '-std=c23' onwards include/linux/types.h:30:1: warning: useless type name in empty declaration 30 | typedef _Bool bool; | ^~~~~~~
The fix is similar to commit ee2ab467bddf ("x86/boot: Use '-std=gnu11' to fix build with GCC 15") which has been backported to this kernel.
Note: In < 5.18 version, -std=gnu89 is used instead of -std=gnu11, see commit e8c07082a810 ("Kbuild: move to -std=gnu11"). I suggest not to modify that in this commit here as all the other similar fixes to support GCC 15 set -std=gnu11. This can be done in a dedicated commit if needed. There was a conflict, because commit 2838307b019d ("x86/build: Remove -m16 workaround for unsupported versions of GCC") is not in this version and change code in the context. -std=gnu11 can still be added at the same place. ] Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- Cc: Nathan Chancellor nathan@kernel.org Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Ard Biesheuvel ardb@kernel.org --- arch/x86/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 8b9fa777f513..f584d07095f1 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -31,7 +31,7 @@ endif CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
-REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ +REALMODE_CFLAGS := -std=gnu11 $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)