Re: [PATCH] objtool/x86: add missing embedded_insn check

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Oct 25, 2023 at 10:35:08PM -0700, John Sperbeck wrote:
> On Wed, Oct 25, 2023 at 10:17 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Thu, Oct 26, 2023 at 01:57:28AM +0000, John Sperbeck wrote:
> > > When dbf460087755 ("objtool/x86: Fixup frame-pointer vs rethunk")
> > > was backported to some stable branches, the check for dest->embedded_insn
> > > in is_special_call() was missed.  Add it back in.
> > >
> > > Signed-off-by: John Sperbeck <jsperbeck@google.com>
> > > ---
> > >
> > >
> > > I think 6.1.y, 5.15.y, and 5.10.y are the LTS branches missing the
> > > bit of code that this patch re-adds.
> >
> > Did you test this and find it solved anything for you?  Your changelog
> > is pretty sparse :(
> >
> > thanks,
> >
> > greg k-h
> 
> I wasn't sure what to write for the comment.  The original backported
> commit said that it prevented this objtool warning:
> 
>     vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without
> frame pointer save/setup
> 
> But because of the missing piece, the warning still appears.  That is,
> the backport had no effect at all.

Perhaps say that?

> With this patch, the message really is gone in my builds.  Shall I
> resend my patch with an updated comment?

Build warnings going away is good, but does the result still run
properly?

> I also wasn't sure whether a Fixes annotation was appropriate, and
> which commit to reference, if so.

That's fine, just more information might be nice here.

thanks,

greg k-h