On June 1, 2018 9:55:49 AM PDT, Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: >The top level Makefile explicitly sets the C standard used in the >kernel >to gnu89. By overriding KBUILD_CFLAGS, the C standard used for this >subdir is now implicit based on compiler and compiler version. GCC >changes this implicit default from gnu89 to gnu11 in v5.1. > >This implies that depending on compiler version, parts of the kernel >are >being linked together from object files that were compiled with >different C standard compiler flags. > >This is problematic for symbols declared as extern inline, as the >semantics have switched since gnu89. See also: >http://blahg.josefsipek.net/?p=529 > >Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> >Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> >--- > arch/x86/boot/compressed/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/arch/x86/boot/compressed/Makefile >b/arch/x86/boot/compressed/Makefile >index fa42f895fdde..1a04c7e9add1 100644 >--- a/arch/x86/boot/compressed/Makefile >+++ b/arch/x86/boot/compressed/Makefile >@@ -26,7 +26,7 @@ KCOV_INSTRUMENT := n >targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 >vmlinux.bin.lzma \ > vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 > >-KBUILD_CFLAGS := -m$(BITS) -O2 >+KBUILD_CFLAGS := -m$(BITS) -O2 -std=gnu89 > KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) > KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING > cflags-$(CONFIG_X86_32) := -march=i386 -fgnu-inlines would be a better option. We could also simply #define inline inline __attribute__((gnu_inline)) -- Sent from my Android device with K-9 Mail. Please excuse my brevity. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
