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[Anton Blanchard <anton@xxxxxxxxx>]

(gdb) break /home/ubuntu/binutils-gdb/gdb/testsuite/gdb.base/annota1.c:28
Breakpoint 1 at 0x100006e4: file /home/ubuntu/binutils-gdb/gdb/testsuite/gdb.base/annota1.c, line 28.

(gdb) run
Starting program: /tmp/foo 
Can't read symbols from system-supplied DSO at 0x3fffb7fa0000: File truncated

Breakpoint 1, main () at /home/ubuntu/binutils-gdb/gdb/testsuite/gdb.base/annota1.c:28
28        int my_array[3] = { 1, 2, 3 };  /* break main */


I wonder if the gdb complaint about the kernel VDSO is causing the test to fail. The warning is almost certainly a result of
this kernel patch:


commit 24b659a13866b935eca72748ce725279bd3c4466
Author: Anton Blanchard <anton@xxxxxxxxxxx>
Date:   Wed Feb 12 17:18:50 2014 +1100

    powerpc: Use unstripped VDSO image for more accurate profiling data

    We are seeing a lot of hits in the VDSO that are not resolved by perf.
    A while(1) gettimeofday() loop shows the issue:
    
    27.64%  [vdso]  [.] 0x000000000000060c
    22.57%  [vdso]  [.] 0x0000000000000628
    16.88%  [vdso]  [.] 0x0000000000000610
    12.39%  [vdso]  [.] __kernel_gettimeofday
     6.09%  [vdso]  [.] 0x00000000000005f8
     3.58%  test    [.] 00000037.plt_call.gettimeofday@@GLIBC_2.18
     2.94%  [vdso]  [.] __kernel_datapage_offset
     2.90%  test    [.] main
    
    We are using a stripped VDSO image which means only symbols with
    relocation info can be resolved. There isn't a lot of point to
    stripping the VDSO, the debug info is only about 1kB:
    
    4680 arch/powerpc/kernel/vdso64/vdso64.so
    5815 arch/powerpc/kernel/vdso64/vdso64.so.dbg
    
    By using the unstripped image, we can resolve all the symbols in the
    VDSO and the perf profile data looks much better:
    
    76.53%  [vdso]  [.] __do_get_tspec
    12.20%  [vdso]  [.] __kernel_gettimeofday
     5.05%  [vdso]  [.] __get_datapage
     3.20%  test    [.] main
     2.92%  test    [.] 00000037.plt_call.gettimeofday@@GLIBC_2.18

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https://bugs.launchpad.net/bugs/1365664

Title:
  gdb source test suites are failing in Ubuntu14.10

Status in “gdb” package in Ubuntu:
  Confirmed

Bug description:
  ---Problem Description---
  gdb source test suites are failing in Ubuntu14.10
   
  Machine Type = P8 
   
  ---Steps to Reproduce---
  Install a P8 system with Power KVM and then install Ubuntu 14.10 guest.
  Then try to build and execute the gdb source test suites as below.

  root@ubuntu:~# apt-get source gdb
  root@ubuntu:~# cd gdb-7.8/
  root@ubuntu:~/gdb-7.8# dpkg-buildpackage -b 2>&1 | tee gdblog

                  === gdb Summary ===

  # of expected passes            25009
  # of unexpected failures        287
  # of unexpected successes       2
  # of expected failures          66
  # of unknown successes          1
  # of known failures             59
  # of unresolved testcases       3
  # of untested testcases         19
  # of unsupported tests          100

   
  ---uname output---
  Linux ubuntu 3.16.0-11-generic #16-Ubuntu SMP Mon Aug 25 20:02:00 UTC 2014 ppc64le ppc64le ppc64le GNU/Linux
   
  I've retested gdb from Ubuntu 14.04 (gdb-7.7-0ubuntu3.1) in the Ubuntu 14.10 VM provided by Pavaman and the number of failures curiously increased to 250 (in comparison to less than 140 on 14.04), which leads me to believe that there is something in the environment of Ubuntu 14.10 compromising gdb functionality in several testcases.

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