Re: [PATCH 5.15 v2 1/5] arch: fix broken BuildID for arm64 and riscv

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Feb 10, 2023 at 01:18:40PM -0700, Tom Saeger wrote:
> From: Masahiro Yamada <masahiroy@kernel.org>
> 
> commit 99cb0d917ffa1ab628bb67364ca9b162c07699b1 upstream.
> 
> Dennis Gilmore reports that the BuildID is missing in the arm64 vmlinux
> since commit 994b7ac1697b ("arm64: remove special treatment for the
> link order of head.o").
> 
> The issue is that the type of .notes section, which contains the BuildID,
> changed from NOTES to PROGBITS.
> 
> Ard Biesheuvel figured out that whichever object gets linked first gets
> to decide the type of a section. The PROGBITS type is the result of the
> compiler emitting .note.GNU-stack as PROGBITS rather than NOTE.
> 
> While Ard provided a fix for arm64, I want to fix this globally because
> the same issue is happening on riscv since commit 2348e6bf4421 ("riscv:
> remove special treatment for the link order of head.o"). This problem
> will happen in general for other architectures if they start to drop
> unneeded entries from scripts/head-object-list.txt.
> 
> Discard .note.GNU-stack in include/asm-generic/vmlinux.lds.h.
> 
> Link: https://lore.kernel.org/lkml/CAABkxwuQoz1CTbyb57n0ZX65eSYiTonFCU8-LCQc=74D=xE=rA@mail.gmail.com/
> Fixes: 994b7ac1697b ("arm64: remove special treatment for the link order of head.o")
> Fixes: 2348e6bf4421 ("riscv: remove special treatment for the link order of head.o")

Why are we adding a commit to 5.15.y that fixes an issue that only
showed up in 6.1.y?

We need a good comment somewhere saying why this is needed...

thanks,

greg k-h