[v3,00/11] gdbstub: Implement follow-fork-mode child

Message

Ilya Leoshkevich Feb. 16, 2024, 1:05 p.m. UTC

v2: https://lists.gnu.org/archive/html/qemu-devel/2024-02/msg00810.html
v2 -> v3: Rebase on top of master.
          Fix a typo in the 01/11 commit message.

v1: https://lists.gnu.org/archive/html/qemu-devel/2024-01/msg06646.html
v1 -> v2: Factor out a number of prep patches;
          Add a state transition diagram comment (Alex).
          Improve a few comments;
          Extend the ts_tid fix to bsd.

Hi,

I needed to debug a linux-user crash between fork() and exec() [1] and
realized that gdbstub does not allow this. This series lifts this
restriction (one still cannot debug past exec() though). Patches 1-9
are preliminary refactorings, patch 10 is the implementation, and patch
11 is the test.

[1] https://lists.gnu.org/archive/html/qemu-devel/2024-01/msg06424.html

Best regards,
Ilya

Ilya Leoshkevich (11):
  gdbstub: Support disablement in a multi-threaded process
  {linux,bsd}-user: Update ts_tid after fork()
  gdbstub: Introduce gdbserver_fork_start()
  {linux,bsd}-user: Pass pid to fork_end()
  {linux,bsd}-user: Pass pid to gdbserver_fork()
  gdbstub: Call gdbserver_fork() both in parent and in child
  gdbstub: Introduce gdb_handle_query_supported_user()
  gdbstub: Introduce gdb_handle_set_thread_user()
  gdbstub: Introduce gdb_handle_detach_user()
  gdbstub: Implement follow-fork-mode child
  tests/tcg: Add two follow-fork-mode tests

 bsd-user/freebsd/os-proc.h                    |   6 +-
 bsd-user/main.c                               |   9 +-
 bsd-user/qemu.h                               |   2 +-
 gdbstub/gdbstub.c                             |  29 ++-
 gdbstub/internals.h                           |   3 +
 gdbstub/user.c                                | 244 +++++++++++++++++-
 include/gdbstub/user.h                        |  11 +-
 linux-user/main.c                             |   8 +-
 linux-user/syscall.c                          |   6 +-
 linux-user/user-internals.h                   |   2 +-
 tests/tcg/multiarch/Makefile.target           |  17 +-
 tests/tcg/multiarch/follow-fork-mode.c        |  56 ++++
 .../gdbstub/follow-fork-mode-child.py         |  40 +++
 .../gdbstub/follow-fork-mode-parent.py        |  16 ++
 14 files changed, 424 insertions(+), 25 deletions(-)
 create mode 100644 tests/tcg/multiarch/follow-fork-mode.c
 create mode 100644 tests/tcg/multiarch/gdbstub/follow-fork-mode-child.py
 create mode 100644 tests/tcg/multiarch/gdbstub/follow-fork-mode-parent.py