| Message ID | 20250322000940.778730-1-raj.khem@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mips: Add '-std=gnu11' to vdso CFLAGS | expand |
On Fri, Mar 21, 2025 at 05:09:40PM -0700 Khem Raj wrote: > GCC 15 changed the default C standard dialect from gnu17 to gnu23, > which should not have impacted the kernel because it explicitly requests > the gnu11 standard in the main Makefile. However, mips/vdso code uses > its own CFLAGS without a '-std=' value, which break with this dialect > change because of the kernel's own definitions of bool, false, and true > conflicting with the C23 reserved keywords. > > 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 > > Add '-std=gnu11' to the decompressor and purgatory CFLAGS to eliminate > these errors and make the C standard version of these areas match the > rest of the kernel. > > Signed-off-by: Khem Raj <raj.khem@gmail.com> > Cc: stable@vger.kernel.org > --- > arch/mips/vdso/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile > index b289b2c1b294..15521004c563 100644 > --- a/arch/mips/vdso/Makefile > +++ b/arch/mips/vdso/Makefile > @@ -30,7 +30,7 @@ cflags-vdso := $(ccflags-vdso) \ > -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ > -mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \ > -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ > - $(call cc-option, -fno-asynchronous-unwind-tables) > + $(call cc-option, -fno-asynchronous-unwind-tables) -std=gnu11 > aflags-vdso := $(ccflags-vdso) \ > -D__ASSEMBLY__ -Wa,-gdwarf-2 > Thanks for the patch. Did you evaluate adding a line like $(filter -std=%,$(KBUILD_CFLAGS)) \ to the assignment of ccflags-vdso? Then MIPS VDSO C standard keeps aligned with top-level. Nevertheless, Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index b289b2c1b294..15521004c563 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -30,7 +30,7 @@ cflags-vdso := $(ccflags-vdso) \ -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ -mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \ -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ - $(call cc-option, -fno-asynchronous-unwind-tables) + $(call cc-option, -fno-asynchronous-unwind-tables) -std=gnu11 aflags-vdso := $(ccflags-vdso) \ -D__ASSEMBLY__ -Wa,-gdwarf-2
GCC 15 changed the default C standard dialect from gnu17 to gnu23, which should not have impacted the kernel because it explicitly requests the gnu11 standard in the main Makefile. However, mips/vdso code uses its own CFLAGS without a '-std=' value, which break with this dialect change because of the kernel's own definitions of bool, false, and true conflicting with the C23 reserved keywords. 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 Add '-std=gnu11' to the decompressor and purgatory CFLAGS to eliminate these errors and make the C standard version of these areas match the rest of the kernel. Signed-off-by: Khem Raj <raj.khem@gmail.com> Cc: stable@vger.kernel.org --- arch/mips/vdso/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)