[PATCH 0/8] Add support for $_siginfo on FreeBSD

[John Baldwin <jhb at FreeBSD dot org>]

This series adds support for $_siginfo for both live processes and
process cores.  siginfo_t for threads is only stored in a per-thread
ELF core note on FreeBSD 12.0 and later.

The existing code in corelow.c for siginfo_t assumed the Linux-specific
NT_SIGINFO ELF core note, but FreeBSD stores siginfo as one member of a
larger ELF core note.  To accomodate this, I added a new gdbarch method
that is used to fetch the signal information from a core dump.  I moved
the body of the existing core_get_siginfo function into an implementation
of the new gdbarch method in linux-tdep.c.

Tested on FreeBSD/amd64 (64-bit and 32-bit binaries), FreeBSD/i386,
and Centos/x86-64 (no regressions in test suite for this last).

John Baldwin (8):
  Implement the "get_siginfo_type" gdbarch method for FreeBSD
    architectures.
  Fetch signal information for native FreeBSD processes.
  Move the thread_section_name class to gdbcore.h.
  Add a new gdbarch method to fetch signal information from core files.
  Use the thread_section_name helper class in fbsd_core_thread_name.
  Recognize the recently-added FreeBSD core dump note for LWP info.
  Create psuedo sections for FreeBSD NT_PTLWPINFO core notes.
  Read signal information from FreeBSD core dumps.

 bfd/ChangeLog        |   4 ++
 bfd/elf.c            |   4 ++
 binutils/ChangeLog   |   4 ++
 binutils/readelf.c   |   2 +
 gdb/ChangeLog        |  43 +++++++++++
 gdb/corelow.c        |  82 ++++-----------------
 gdb/fbsd-nat.c       | 155 ++++++++++++++++++++++++++++++++++++++++
 gdb/fbsd-tdep.c      | 197 +++++++++++++++++++++++++++++++++++++++++++++++++--
 gdb/gdbarch.c        |  32 +++++++++
 gdb/gdbarch.h        |  10 +++
 gdb/gdbarch.sh       |   5 ++
 gdb/gdbcore.h        |  45 ++++++++++++
 gdb/linux-tdep.c     |  21 ++++++
 include/ChangeLog    |   4 ++
 include/elf/common.h |   1 +
 15 files changed, 536 insertions(+), 73 deletions(-)

-- 
2.11.0