Re: [PATCH] RISC-V: Segment fault in riscv_elf_append_rela.

[Nelson Chu <nelson@rivosinc.com>]

Thanks for the suggestion :) Seems like there are two better solution for now,

1.  Add the BFD_ASSERT before calling every riscv_elf_append_rela to
make sure the written section exists, and then just return in the
riscv_elf_append_rela if the section doesn't exist, to avoid the
segment fault.  We will know which section is NULL, and where the
ASSERT code is.  Besides that, since parts of the callers already have
the BFD_ASSERT check before calling riscv_elf_append_rela, so this
seems the right way to do it.

2. Report error and return false if the section doesn't exist in the
riscv_elf_append_rela, and then the callers "goto out" to release the
unused data structures in the riscv_elf_relocate_section, or return
false if the caller is riscv_elf_finish_dynamic_symbol.  But it is
hard to report the more detailed errors in the riscv_elf_append_rela,
it is not easy to know which caller code meets the problem.

I think solution 1 should be better than solution 2?

Thanks
Nelson

On Thu, Mar 9, 2023 at 4:34 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Thu, Mar 09, 2023 at 04:04:46PM +0800, Nelson Chu wrote:
> >     * elfnn-riscv.c (riscv_elf_append_rela): Abort when the dynamic section
> >     doesn't exist.
>
> It would be nicer to handle this more gracefully by returning an error
> to the caller.  An abort isn't much better than a segmentation fault
> if this can be triggered by user input.
>
> --
> Alan Modra
> Australia Development Lab, IBM