On Fri, 2018-09-14 at 04:06:47 UTC, Joel Stanley wrote: > When building with clang crt0's _zimage_start is not marked weak, which > breaks the build when linking the kernel image: > > $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ > 0000000000000058 g .text 0000000000000000 _zimage_start > > ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start': > (.text+0x58): multiple definition of '_zimage_start'; > arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here > > Clang requires the .weak directive to appear after the symbol is > declared. The binutils manual says: > > This directive sets the weak attribute on the comma separated list of > symbol names. If the symbols do not already exist, they will be > created. > > So it appears this is different with clang. The only reference I could > see for this was an OpenBSD mailing list post[1]. > > Changing it to be after the declaration fixes building with Clang, and > still works with GCC. > > $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ > 0000000000000058 w .text 0000000000000000 _zimage_start > > Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921 > > [1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY > > Signed-off-by: Joel Stanley <j...@jms.id.au> > Reviewed-by: Nick Desaulniers <ndesaulni...@google.com>
Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/ee9d21b3b3583712029a0db65a4b7c cheers
