On Wed, May 20, 2020 at 11:20:10AM -0700, 'Fangrui Song' via Clang Built Linux wrote: > In the latest efi tree, ce5e3f909fc0ed67e58367b9c56a54c20a51080b > "efi/printf: Add 64-bit and 8-bit integer support", > arch/x86/boot/compressed/vmlinux may have an undesired > .discard.unreachable section from drivers/firmware/efi/libstub/vsprintf.stub.o > > .discard.unreachable contains an R_X86_64_PC32 relocation, which will be > warned by LLD: a non-SHF_ALLOC section (.discard.unreachable) is not > part of the memory image, thus conceptually the distance between a > non-SHF_ALLOC and a SHF_ALLOC is not a constant which can be resolved at > link time. > > % ld.lld -m elf_x86_64 -T arch/x86/boot/compressed/vmlinux.lds ... -o arch/x86/boot/compressed/vmlinux > ld.lld: warning: vsprintf.c:(.discard.unreachable+0x0): has non-ABS relocation R_X86_64_PC32 against symbol '' > > Reuse the DISCARDS macro which includes .discard.* to drop .discard.unreachable > > Reported-by: kbuild test robot <lkp@xxxxxxxxx> > Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx> Yay macro usage! :) Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
