Request to backport b3bee1e7c3f2b1b77182302c7b2131c804175870 (x86/boot: Compile boot code with -std=gnu11 too)
Hello,
with gcc 15.1.1 i see the following build issue on 6.6.91:
CC arch/x86/boot/a20.o 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/boot/boot.h:22, from arch/x86/boot/a20.c:14: ./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:35:33: error: 'bool' cannot be defined via 'typedef' 35 | typedef _Bool bool; | ^~~~ ./include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards ./include/linux/types.h:35:1: warning: useless type name in empty declaration 35 | typedef _Bool bool; | ^~~~~~~ make[2]: *** [scripts/Makefile.build:243: arch/x86/boot/a20.o] Error 1 make[1]: *** [arch/x86/Makefile:284: bzImage] Error 2
Fixed by b3bee1e7c3f2b1b77182302c7b2131c804175870 (x86/boot: Compile boot code with -std=gnu11 too), which hasn't been backported yet.
Should probably go into all stable trees.
Regards, Hendrik
On Mon, May 26, 2025 at 12:59:20PM +0200, Hendrik Donner wrote:
Hello,
with gcc 15.1.1 i see the following build issue on 6.6.91:
CC arch/x86/boot/a20.o 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/boot/boot.h:22, from arch/x86/boot/a20.c:14: ./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:35:33: error: 'bool' cannot be defined via 'typedef' 35 | typedef _Bool bool; | ^~~~ ./include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards ./include/linux/types.h:35:1: warning: useless type name in empty declaration 35 | typedef _Bool bool; | ^~~~~~~ make[2]: *** [scripts/Makefile.build:243: arch/x86/boot/a20.o] Error 1 make[1]: *** [arch/x86/Makefile:284: bzImage] Error 2
Fixed by b3bee1e7c3f2b1b77182302c7b2131c804175870 (x86/boot: Compile boot code with -std=gnu11 too), which hasn't been backported yet.
Should probably go into all stable trees.z
Is this the only change that is needed to get gcc15 working on this kernel tree? What about newer kernel branches, they seem to be failing on gcc15 still, which implies that 6.6.y still needs more changes, right?
thanks,
greg k-h
Hello,
On 26.05.25 14:23, Greg KH wrote:
On Mon, May 26, 2025 at 12:59:20PM +0200, Hendrik Donner wrote:
Hello,
with gcc 15.1.1 i see the following build issue on 6.6.91:
CC arch/x86/boot/a20.o 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/boot/boot.h:22, from arch/x86/boot/a20.c:14: ./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:35:33: error: 'bool' cannot be defined via 'typedef' 35 | typedef _Bool bool; | ^~~~ ./include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards ./include/linux/types.h:35:1: warning: useless type name in empty declaration 35 | typedef _Bool bool; | ^~~~~~~ make[2]: *** [scripts/Makefile.build:243: arch/x86/boot/a20.o] Error 1 make[1]: *** [arch/x86/Makefile:284: bzImage] Error 2
Fixed by b3bee1e7c3f2b1b77182302c7b2131c804175870 (x86/boot: Compile boot code with -std=gnu11 too), which hasn't been backported yet.
Should probably go into all stable trees.z
Is this the only change that is needed to get gcc15 working on this kernel tree? What about newer kernel branches, they seem to be failing on gcc15 still, which implies that 6.6.y still needs more changes, right?
that is the only fix i need on 6.6.x with the kernel configuration i test and build for an x86_64 production environment. I also build arm32 and aarch64 kernel configuration for a few embedded systems with gcc 15.1.1 natively and cross, without issues. But according to the git history gcc 15 related fixes have already been integrated over the last few years into mainline and stable trees, so shouldn't be too much left. The default KBUILD_CFLAGS include --std=gnu11 in the toplevel Makefile, which takes care of a lot.
That said i haven't done extensive testing with other kernel configurations, just what our internal CI is building.
Regards, Hendrik
thanks,
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Hendrik Donner