From: Markus <M4rkusXXL@web.de>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>
Subject: Re: objtool segfault with ORC unwinder enabled
Date: Thu, 11 Jan 2018 19:11:03 +0100
Message-ID: <1574206.L1kTMSv4rA@markus>
In-Reply-To: <20180111042551.ds6vjhnqbradc52a@treble>
References: <1537667.mbZVOcHbLR@markus> <20180111041300.tr57lsn7c54ggx7c@treble> <20180111042551.ds6vjhnqbradc52a@treble>
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On Thursday, 11 January 2018 05:25:51 CET Josh Poimboeuf wrote:
> On Wed, Jan 10, 2018 at 10:13:00PM -0600, Josh Poimboeuf wrote:
> > On Wed, Jan 10, 2018 at 06:14:56PM +0100, Markus wrote:
> > > On Thursday, 4 January 2018 19:25:12 CET Markus wrote:
> > > > On Thursday, 4 January 2018 18:32:03 CET Josh Poimboeuf wrote:
> > > > > On Thu, Jan 04, 2018 at 05:56:30PM +0100, Markus wrote:
> > > > > > On Thursday, 4 January 2018 16:46:13 CET Josh Poimboeuf wrote:
> > > > > > > I don't see anything unusual there.  Are there any Gentoo
> > > > > > > patches
> > > > > > > against either the kernel or GCC which would strip unused
> > > > > > > symbols?
> > > > > > 
> > > > > > The kernel is the vanilla kernel. (4.14.11 and also 4.15-rc6)
> > > > > > Its not a gentoo specific gcc patch. (Then every gentoo user would
> > > > > > be
> > > > > > affected?)
> > > > > > 
> > > > > > But I enabled ld.gold as default linker like 5 years ago. Never
> > > > > > had a
> > > > > > problem with this.
> > > > > > 
> > > > > > Is ld.gold supposed to fail here?
> > > > > > 
> > > > > > I switched back to ld.bfd and it seems to work.
> > > > > 
> > > > > Ah, that explains it.  With CONFIG_MODVERSIONS, the linker does some
> > > > > work after gcc, but before objtool.  Can you try this patch?  (Note
> > > > > this
> > > > > isn't the final patch, as this breaks the CONFIG_MODVERSIONS=n
> > > > > case.)
> > > 
> > > Any more final patch I should test?
> > 
> > Sorry, this fell off my radar.  I'll try to get a final patch soon.
> > (But feel free to keep bugging me if I don't!)
> 
> Ok, this should be the final patch (no description yet though).  Want to
> test it?

Tried to apply to 4.14.13 and 4.15-rc7. Neither applied cleanly.
Manually editing just breaks the build with many "open: No such file or 
directory".

Dont know what went wrong. Can you maybe append patch as file?

BR,
Markus