[PATCH] gas: Fix internal error in S_SET_SEGMENT

[H.J. Lu]

On Wed, Jul 22, 2020 at 7:24 AM Alex Coplan <alex.coplan@arm.com> wrote:
>
> Hello,
>
> This patch fixes an internal error in GAS when defining a section using
> a symbol that has already been named but not defined. For a minimal
> reproducer, try the following input:
>
> a=b
> .sect a
>
> The problem is that obj_elf_change_section() happily reuses the symbol
> "a" created by equals() without clearing the sy_value field: prior to
> this patch, it just set bsym. This caused a problem when attempting to
> resolve the section symbol, since resolve_symbol_value() ended up
> resolving the symbol as if it were the original symbol created by
> equals(), which ends up leaving the section symbol in the undefined
> section instead of in section a, hence the call to abort() in
> S_SET_SEGMENT().
>
> Testing:
>  * New test fails before and passes after the change.
>  * Regression tested on a wide variety of targets.
>
> OK for master?
>
> Thanks,
> Alex
>
> ---
>
> gas/ChangeLog:
>
> 2020-07-22  Alex Coplan  <alex.coplan@arm.com>
>
>         * config/obj-elf.c (obj_elf_change_section): When
>         repurposing an existing symbol, ensure that we set sy_value as
>         per other (fresh) section symbols.
>         * testsuite/gas/aarch64/section-symbol-redef.d: New test.
>         * testsuite/gas/aarch64/section-symbol-redef.s: Input for test.
>

Why are tests arm specific?  Can you put them to ELF tests?

-- 
H.J.