On Fri, Dec 11, 2020 at 10:37:48AM -0600, Josh Poimboeuf wrote:
> On Fri, Dec 11, 2020 at 10:32:05AM +0100, Peter Zijlstra wrote:
> > Looking at elf.c, it seems we're missing an STT_SECTION symbol for
> > .text.
> >
> > And indeed, when I add -fno-asynchronous-unwind-tables to clang-11, that
> > goes missing from the readelf .symtab listing. Help ?!
>
> I had a similar problem with ORC relocations:
>
> e81e07244325 ("objtool: Support Clang non-section symbols in ORC
> generation")
>
> If Clang strips the section symbol then we have to find the function
> symbol instead.
Argh, I knew I'd seen something like that before, but I couldn't find it :-/
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index c6ab44543c92..9bc18864154f 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -472,8 +472,25 @@ static int create_static_call_sections(struct
> objtool_file *file)
> return -1;
> }
> memset(reloc, 0, sizeof(*reloc));
> - reloc->sym = insn->sec->sym;
> - reloc->addend = insn->offset;
> +
> + if (insn->sec->sym) {
> + reloc->sym = insn->sec->sym;
> + reloc->addend = insn->offset;
> + } else {
> + reloc->sym = find_symbol_containing(insn->sec,
> insn->offset);
> + if (!reloc->sym) {
> + WARN_FUNC("can't create static call: missing
> containing symbol",
> + insn->sec, insn->offset);
> + return -1;
> + }
> +
> + reloc->addend = insn->offset - reloc->sym->offset;
> + }
> +
Do we want to capture all that gunk in something like
elf_reloc_to_insn(reloc, insn) instead of duplicating the magic?
