On Wed, Dec 16, 2020 at 04:40:51PM -0800, Nick Desaulniers wrote:
With newer GNU binutils, linking with BFD produces warnings for vmlinux: aarch64-linux-gnu-ld: warning: -z norelro ignored
BFD can produce this warning when the target emulation mode does not support RELRO relocation types, and -z relro or -z norelro is passed.
Alan Modra clarifies: The default linker emulation for an aarch64-linux ld.bfd is -maarch64linux, the default for an aarch64-elf linker is -maarch64elf. They are not equivalent. If you choose -maarch64elf you get an emulation that doesn't support -z relro.
The ARCH=arm64 kernel prefers -maarch64elf, but may fall back to -maarch64linux based on the toolchain configuration.
LLD will always create RELRO relocation types regardless of target emulation.
To avoid the above warning when linking with BFD, pass -z norelro only when linking with LLD or with -maarch64linux.
Given that, prior to 3b92fa7485eb, we used to pass '-z norelro' if CONFIG_RELOCATABLE then was this already broken with the ELF toolchain?
Will