Re: libelf-0.175 breaks objtool

From: Arnd Bergmann
Date: Mon Apr 06 2020 - 17:07:36 EST


On Wed, Feb 6, 2019 at 7:32 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Tue, 5 Feb 2019 20:16:11 -0600 Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
>
> > On Tue, Feb 05, 2019 at 01:38:21PM -0500, Steven Rostedt wrote:
> > > Just a FYI.
> > >
> > > After a recent upgrade in debian testing, I was not able to build the
> > > kernel. I have a custom build of gcc, so I thought it was strange that
> > > I was getting something like this (took this from the web, as I don't
> > > have the error anymore with the work around, and currently doing a full
> > > build):
> > >
> > > objdump: kernel/.tmp_signal.o: unable to initialize decompress status for section .debug_info
> > > objdump: kernel/.tmp_signal.o: unable to initialize decompress status for section .debug_info
> > > objdump: kernel/.tmp_signal.o: file format not recognized
> > > CC arch/x86/kernel/platform-quirks.o
> > > objdump: arch/x86/kernel/.tmp_ebda.o: unable to initialize decompress status for section .debug_info
> > > objdump: arch/x86/kernel/.tmp_ebda.o: unable to initialize decompress status for section .debug_info
> > > objdump: arch/x86/kernel/.tmp_ebda.o: file format not recognized
> > > objdump: mm/.tmp_swap_slots.o: unable to initialize decompress status for section .debug_info
> > > objdump: mm/.tmp_swap_slots.o: unable to initialize decompress status for section .debug_info
> > > objdump: mm/.tmp_swap_slots.o: file format not recognized
> >
> > I installed debian testing on a VM, which has libelf 0.175-2, but I
>
> Hmm, I only have libelf-0.175 (no -2)
>
> > can't recreate. Can you share your config?
> >
>
> It's just a distro config. Ah, I think it's because I'm compiling my
> own home built gcc. There seems to be an incompatibility with the
> binutils that I used and with libelf-0.175. If I build with just the
> distro gcc, it works.
>
> Bah, this means I need to recreate my gcc that I use to build my
> kernels with :-p As I like to control which gcc I use.

I now see the same problem that you reported using the gcc-9
toolchain I provide on https://kernel.org/pub/tools/crosstool/.

Do you have any other information that might help me fix it?

Arnd