Re: [PATCH] arm64: link with -z norelro for LLD or aarch64-elf

[Will Deacon]

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