(In reply to Mark Wielaard from comment #0)
> Note that independently of this bug, there is actually a bug in elfutils.
> elfutils doesn't expect .gnu.attributes sections for EM_PPC64, only for
> EM_PPC. I'll fix that, but it won't be able to make sense of the zero-filled
> section.

I fixed that and added the patches to the fedora elfutils rawhide package:

0.168-5 - Add patches for new gcc warnings and new binutils ppc64 attributes.
  - elfutils-0.168-libasm-truncation.patch
  - elfutils-0.168-ppc64-attrs.patch

It still fails on ppc64/ppc64le because of the zeroed out .gnu.attributes section with SHF_EXCLUDE flag.

Hi Mark,

> Building elfutils triggers a bad "self test" running eu-elflint against
> binutils-2.27-16.fc26.ppc64le. It is caused by one of the binaries having a
> .gnu.attributes section with the SHF_EXCLUDE flag set and containing only
> zeros.

Would it be possible for you to isolate the compilation that is producing the broken binary, and post it here ?

I think that this bug *might* be fixed by:

  https://www.sourceware.org/ml/binutils/2016-09/msg00167.html

but I would like to be able to check it first.

Cheers
  Nick

Simplest reproducer is:

$ cat  t.c
#include <stdio.h>

double d = 1.0;

int
main (int argc, char **argv)
{
  printf ("double: %f\n", d);
}
$ gcc -g -O2 -c t.c
$ gcc -o t t.o
$ eu-readelf -x .gnu.attributes t.o

Hex dump of section [23] '.gnu.attributes', 16 bytes at offset 0xa50:
  0x00000000 410f0000 00676e75 00010700 00000401 A....gnu........
$ eu-readelf -x .gnu.attributes t

Hex dump of section [33] '.gnu.attributes', 16 bytes at offset 0x109e1:
  0x00000000 00000000 00000000 00000000 00000000 ................
$ eu-readelf -S t.o | grep .gnu.attributes 
[23] .gnu.attributes      GNU_ATTRIBUTES 0000000000000000 00000a50 00000010  0        0   0  1
$ eu-readelf -S t | grep .gnu.attributes[33] .gnu.attributes      GNU_ATTRIBUTES 0000000000000000 000109e1 00000010  0 E      0   0  1

(With the fixed eu-readelf version you will also be able to use eu-readelf -A to show the actual gnu attributes. But as you can see the bytes in the EXEC are zeroed and the SHF_EXCLUDE flag on the section, which is the actual bug in this case.)

Hi Mark,

> $ gcc -o t t.o

Could you upload that t.o file please ?

I am trying to reproduce this problem on a F25 ppc64le box, but the gcc installed on that system does not create a .gnu.attributes section.  (I could not find an F26 ppc64le installation ... :-(

Cheers
  Nick

Created attachment 1250930 [details]
gcc -g -O2 -c t.c

Build with:

gcc-7.0.1-0.6.fc26.ppc64le
binutils-2.27-16.fc26.ppc64le

*** Bug 1423518 has been marked as a duplicate of this bug. ***

Hi Mark,

  Thanks - with that t.o file I can now reproduce the problem, and I believe
  that I have found a solution.  The problem was that the rawhide gcc is
  newer than the rawhide binutils, and in particular it is generating an
  attribute value for the Floating Point Size which the binutils were not
  expecting.

  Fortunately it turns out that Alan Modra's patch mentioned in comment #2
  fixes this problem.  So please could you try out binutils-2.27-19.fc26
  which contains this patch.

Cheers
  Nick

I rebuild elfutils against 2.27-19.fc26 and on both ppc64 and ppc64le it now has zero FAIL. Thanks.