This is the mail archive of the gdb-prs@sourceware.org mailing list for the GDB project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug gdb/20505] warning: Could not load shared library symbols for linux-vdso.so.1 (debugging core file)


https://sourceware.org/bugzilla/show_bug.cgi?id=20505

--- Comment #2 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The gdb-7.12-branch branch has been updated by Pedro Alves
<palves@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=601a2a8f639f9ef6dab86118a87fa67861f2091e

commit 601a2a8f639f9ef6dab86118a87fa67861f2091e
Author: Pedro Alves <palves@redhat.com>
Date:   Mon Aug 22 20:22:35 2016 +0100

    Fix PR gdb/20505 - Make vDSO detection work with core files

    Loading a core dump that was either generated on a system running
    pristine glibc master, or on a Fedora/RHEL system with LD_DEBUG=unused
    set in the environment, solib-svr4.c:svr4_current_sos fails to filter
    out the vDSO, resulting in:

      (gdb) core-file corefile.core^M
      [New LWP 2362]^M
      warning: Could not load shared library symbols for linux-vdso.so.1.^M
      Do you need "set solib-search-path" or "set sysroot"?^M
      Core was generated by
`build-gdb/gdb/testsuite/outputs/gdb.base/corefile/'.^M
      ...

    The problem is that gdbarch_vsyscall_range does not support core
    inferiors at all.

    When live debugging, we're finding the vDSO's start address with
    auxv/AT_SYSINFO_EHDR, and then we find the vDSO's size by look for the
    corresponding mapping, by parsing /proc/PID/maps.  When debugging a
    core dump, we can also determine the starting address from
    auxv/AT_SYSINFO_EHDR.  However, we obviously can't read the core
    mappings out of the host's /proc.  But we can instead look for a
    corresponding load segment in the core's bfd.

    gdb/ChangeLog:
    2016-08-22  Pedro Alves  <palves@redhat.com>

        PR gdb/20505
        * linux-tdep.c (linux_vsyscall_range_raw): For core inferiors,
        find the vDSO's start address with AT_SYSINFO_EHDR too, and
        determine the vDSO's size by finding the PT_LOAD segment that
        matches AT_SYSINFO_EHDR.

    gdb/testsuite/ChangeLog:
    2016-08-22  Pedro Alves  <palves@redhat.com>

        PR gdb/20505
        * gdb.base/vdso-warning.exp: Test core dumps too.  Use
        with_test_prefix.  Factor out bits to ...
        (test_no_vdso): ... this new procedure.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]