[PATCH v4 0/8] gdbstub: Add support for info proc mappings

[Ilya Leoshkevich]

v3: https://lists.gnu.org/archive/html/qemu-devel/2023-06/msg01311.html
v3 -> v4: Fix the 32-bit build (Alex).
          Enable the test on all architectures and ignore certain
          expected failures (Alex). I tried this with the latest
          gdb-multiarch and it works. The only skip is on x86_64,
          as expected.

v2: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg06837.html
v2 -> v3: Use openat() instead of safe_openat() (new patch: 2/8).
          Add /proc/self/smaps emulation (new patch: 3/8).
          With these 2 changes, the minor issues previously mentioned in
          the patch 6/8 are gone.

v1: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg02614.html
v1 -> v2: Reword the 5/6 commit message (Dominik).
          Add R-bs.
          Patches that need review:
          4/6 gdbstub: Add support for info proc mappings
          6/6 tests/tcg: Add a test for info proc mappings

Hi,

this series partially implements the Host I/O feature of the GDB Remote
Serial Protocol in order to make generate-core-file work with qemu-user.
It borrows heavily from the abandoned patch by Dominik [1], hence 4/6
carries the respective Co-developed-by: tag. I also peeked at
gdbserver/hostio.cc quite a few times.

The changes compared to Dominik's patch are:

- Implement readlink.
- Move the main functionality to user-target.c.
- Allocate buffers on heap.
- Add a test.
- Update gdb.rst.
- Split refactorings to the existing code into separate patches.
- Rename do_openat() to do_guest_openat().
- Do not retry pread(), since GDB is capable of doing it itself.
- Add an extra sanity check to gdb_handle_query_xfer_exec_file().
- Replace citations of the spec by a single link.

Best regards,
Ilya
Ilya Leoshkevich (8):
  linux-user: Expose do_guest_openat() and do_guest_readlink()
  linux-user: Add "safe" parameter to do_guest_openat()
  linux-user: Emulate /proc/self/smaps
  gdbstub: Expose gdb_get_process() and gdb_get_first_cpu_in_process()
  gdbstub: Report the actual qemu-user pid
  gdbstub: Add support for info proc mappings
  docs: Document security implications of debugging
  tests/tcg: Add a test for info proc mappings

 docs/system/gdb.rst                           |  15 ++
 gdbstub/gdbstub.c                             |  86 ++++++++---
 gdbstub/internals.h                           |   7 +
 gdbstub/user-target.c                         | 139 ++++++++++++++++++
 linux-user/qemu.h                             |   3 +
 linux-user/syscall.c                          | 128 +++++++++++++---
 tests/tcg/multiarch/Makefile.target           |   9 +-
 .../multiarch/gdbstub/test-proc-mappings.py   |  65 ++++++++
 8 files changed, 409 insertions(+), 43 deletions(-)
 create mode 100644 tests/tcg/multiarch/gdbstub/test-proc-mappings.py

-- 
2.40.1