On Wed, May 20, 2020 at 11:20:10AM -0700, Fangrui Song 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> > --- > arch/x86/boot/compressed/vmlinux.lds.S | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S > index 0dc5c2b9614b..8f1025d1f681 100644 > --- a/arch/x86/boot/compressed/vmlinux.lds.S > +++ b/arch/x86/boot/compressed/vmlinux.lds.S > @@ -74,4 +74,6 @@ SECTIONS > #endif > . = ALIGN(PAGE_SIZE); /* keep ZO size page aligned */ > _end = .; > + > + DISCARDS > } > -- > 2.26.2.761.g0e0b3e54be-goog > Thanks! Maybe add a note in the commit message that the section is generated from unreachable() annotations when CONFIG_STACK_VALIDATION is enabled. Tested-by: Arvind Sankar <nivedita@xxxxxxxxxxxx>
