s390: Add '-std=gnu11' to decompressor and purgatory CFLAGS

commit 3b8b80e993766dc96d1a1c01c62f5d15fafc79b9 upstream.

GCC 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, there are certain
places in the s390 code that use their 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.

Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee083@kernel.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 39ffcd4389f10c5a28a7ca39b988d487eb666550..92f2426d87970c960cc7f4e724781b71d1fd6e32 100644 (file)
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -23,7 +23,7 @@ endif
 aflags_dwarf   := -Wa,-gdwarf-2
 KBUILD_AFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -D__ASSEMBLY__
 KBUILD_AFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),$(aflags_dwarf))
-KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2
+KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2 -std=gnu11
 KBUILD_CFLAGS_DECOMPRESSOR += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY
 KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float
 KBUILD_CFLAGS_DECOMPRESSOR += -fno-asynchronous-unwind-tables

diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
index a93c9aba834be1837627783725e68d099b375293..955f113cf3200b284a0f4c2e7630be741ab60794 100644 (file)
--- a/arch/s390/purgatory/Makefile
+++ b/arch/s390/purgatory/Makefile
@@ -20,7 +20,7 @@ GCOV_PROFILE := n
 UBSAN_SANITIZE := n
 KASAN_SANITIZE := n
 
-KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes
+KBUILD_CFLAGS := -std=gnu11 -fno-strict-aliasing -Wall -Wstrict-prototypes
 KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare
 KBUILD_CFLAGS += -fno-zero-initialized-in-bss -fno-builtin -ffreestanding
 KBUILD_CFLAGS += -c -MD -Os -m64 -msoft-float -fno-common