[PATCH v2] elf: Clear the SEC_ALLOC bit for NOLOAD note sections

[Alan Modra]

On Fri, Mar 14, 2025 at 07:33:48AM -0700, H.J. Lu wrote:
> @@ -5965,7 +5965,10 @@ parentheses.  The following types are defined:
>  
>  @item NOLOAD
>  The section should be marked as not loadable, so that it will not be
> -loaded into memory when the program is run.
> +loaded into memory when the program is run.  When generating an ELF
> +output file, the memory space is allocated for the section at run-time,
> +except for SHT_NOTE sections.  For other output files, no memory space
> +is allocated at run-time.

Since we are documenting this, please say that the ELF behaviour is a
bug that may change to be consistent with non-ELF targets.  Patch OK
with that addition.

I see https://sourceware.org/pipermail/binutils/2006-July/048170.html
after this was (likely accidentally) corrected, and the poster
obviously wanted the old buggy ELF behaviour.  Huh, NOLOAD is still
used in linux kernel scripts:
./arch/arm/boot/compressed/vmlinux.lds.S:  .image_end (NOLOAD) : {

Also, we have a number of tests that expect the current ELF behaviour.
ld-elf/noload-1, ld-elf-noload-2 and ld-scripts-output-section-types.
The last one even names a section .rom for expected bss-style
behaviour where it is clear to me that a ROM section ought to have the
non-ELF NOLOAD behaviour.  :-(  At least your new testcase actually
tests for good behaviour.

-- 
Alan Modra