Re: [PATCH v2 07/10] objtool: check: Allow save/restore hint in non standard function symbols

Miroslav Benes
2020-04-01T13:54:06Z

On Fri, 27 Mar 2020, Julien Thierry wrote:

> The kernel code base provides CODE_SYM_START/END to declare assembly
> code sequences that don't follow function standard calling conventions.
>
> As non-C/non-standard code, these sequences can very much benefit from
> unwind hints. However, when a restore unwind_hint is used in a
> non-function code sequence, objtool will crash when looking for the
> corresponding save hint.
>
> Record the code symbol an instruction belongs to and look for save hints
> belonging to the same code symbol as the restore hint.
>
> Signed-off-by: Julien Thierry <jthierry@redhat.com>

Looks ok, but save/restore hints are about to go away. See
https://lore.kernel.org/lkml/20200331222703.GH2452@worktop.programming.kicks-ass.net/

Miroslav