GDB extensions fails with optimized 3.13 due to cframe removal #127147

kasium · 2024-11-22T12:09:14Z

Bug report

Bug description:

When using the python gdb extention python-gdb.py on an optimized python 3.13 installation, gdb shows no backtrace:

Reading symbols from .pyenv/versions/3.13.0/bin/python...
Attaching to program: .pyenv/versions/3.13.0/bin/python, process 53537
Reading symbols from .pyenv/versions/3.13.0/lib/libpython3.13.so.1.0...
Reading symbols from /lib64/libpthread.so.0...
(No debugging symbols found in /lib64/libpthread.so.0)
Reading symbols from /lib64/libdl.so.2...
(No debugging symbols found in /lib64/libdl.so.2)
Reading symbols from /lib64/libutil.so.1...
(No debugging symbols found in /lib64/libutil.so.1)
Reading symbols from /lib64/libm.so.6...
(No debugging symbols found in /lib64/libm.so.6)
Reading symbols from /lib64/libc.so.6...
(No debugging symbols found in /lib64/libc.so.6)
Reading symbols from /lib64/ld-linux-x86-64.so.2...
(No debugging symbols found in /lib64/ld-linux-x86-64.so.2)
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/readline.cpython-313-x86_64-linux-gnu.so...
Reading symbols from /lib64/libreadline.so.7...
(No debugging symbols found in /lib64/libreadline.so.7)
Reading symbols from /lib64/libtinfo.so.6...
(No debugging symbols found in /lib64/libtinfo.so.6)
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/_opcode.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/unicodedata.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/select.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/_struct.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/termios.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/fcntl.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/_curses.cpython-313-x86_64-linux-gnu.so...
Reading symbols from /lib64/libncursesw.so.6...
(No debugging symbols found in /lib64/libncursesw.so.6)
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
0x00007f798865ea53 in poll () from /lib64/libc.so.6
--Type <RET> for more, q to quit, c to continue without paging--
Missing separate debuginfos, use: zypper install glibc-debuginfo-2.31-150300.89.2.x86_64 libncurses6-debuginfo-6.1-150000.5.27.1.x86_64 libreadline7-debuginfo-7.0-150400.27.3.2.x86_64
(gdb) py-bt
Traceback (most recent call first):
  (unable to read python frame information)
  <built-in method exec of module object at remote 0x7f7988499800>
  (unable to read python frame information)

If the same setup is used but python is compiled in non-optimized mode (just don't set the CC and PYTHON_CONFIGURE_OPTS env variable), the backtrace works as expected. Same applies for python 3.12 and lower

Reading symbols from .pyenv/versions/3.13.0/bin/python...
Attaching to program: .pyenv/versions/3.13.0/bin/python, process 79951
Reading symbols from .pyenv/versions/3.13.0/lib/libpython3.13.so.1.0...
Reading symbols from /lib64/libpthread.so.0...
(No debugging symbols found in /lib64/libpthread.so.0)
Reading symbols from /lib64/libdl.so.2...
(No debugging symbols found in /lib64/libdl.so.2)
Reading symbols from /lib64/libutil.so.1...
(No debugging symbols found in /lib64/libutil.so.1)
Reading symbols from /lib64/libm.so.6...
(No debugging symbols found in /lib64/libm.so.6)
Reading symbols from /lib64/libc.so.6...
(No debugging symbols found in /lib64/libc.so.6)
Reading symbols from /lib64/ld-linux-x86-64.so.2...
(No debugging symbols found in /lib64/ld-linux-x86-64.so.2)
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/readline.cpython-313-x86_64-linux-gnu.so...
Reading symbols from /lib64/libreadline.so.7...
(No debugging symbols found in /lib64/libreadline.so.7)
Reading symbols from /lib64/libtinfo.so.6...
(No debugging symbols found in /lib64/libtinfo.so.6)
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/_opcode.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/unicodedata.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/select.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/_struct.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/termios.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/fcntl.cpython-313-x86_64-linux-gnu.so...
Reading symbols from .pyenv/versions/3.13.0/lib/python3.13/lib-dynload/_curses.cpython-313-x86_64-linux-gnu.so...
Reading symbols from /lib64/libncursesw.so.6...
(No debugging symbols found in /lib64/libncursesw.so.6)
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
0x00007f947f668a53 in poll () from /lib64/libc.so.6
--Type <RET> for more, q to quit, c to continue without paging--
Missing separate debuginfos, use: zypper install glibc-debuginfo-2.31-150300.89.2.x86_64 libncurses6-debuginfo-6.1-150000.5.27.1.x86_64 libreadline7-debuginfo-7.0-150400.27.3.2.x86_64
(gdb) py-bt
Traceback (most recent call first):
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/unix_console.py", line 426, in wait
    or bool(self.pollob.poll(timeout))
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/reader.py", line 756, in handle1
    self.console.wait(100)
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/reader.py", line 801, in readline
    self.handle1()
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/readline.py", line 389, in multiline_input
    return reader.readline()
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/simple_interact.py", line 151, in run_multiline_interactive_console
    statement = multiline_input(more_lines, ps1, ps2)
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/main.py", line 59, in interactive_console
    run_multiline_interactive_console(console)
  File ".pyenv/versions/3.13.0/lib/python3.13/_pyrepl/__main__.py", line 6, in <module>
    __pyrepl_interactive_console()
  <built-in method exec of module object at remote 0x7f947f4a5800>
  File "<frozen runpy>", line 88, in _run_code
  File "<frozen runpy>", line 198, in _run_module_as_main

Steps to reproduce

install pyenv incl. all OS packages which are needed
install gcc12
export CC="gcc-12"
export PYTHON_CONFIGURE_OPTS="--enable-shared --with-lto --enable-optimizations"
pyenv install 3.13.0
Open a new python3.13 shell using the just installed python and execute the following commands
6.1. import os
6.2. os.getpid()
6.3. while True: pass
Switch to another shell and execute gdb -q <path-to-pyenv>/versions/3.13.0/bin/python -p <pid>
Wait till gdb spins up and execute py-bt

OS: SUSE Linux Enterprise Server 15 SP4

CPython versions tested on:

3.13

Operating systems tested on:

Linux

The text was updated successfully, but these errors were encountered:

kasium · 2025-01-09T07:18:57Z

I had now some time to dig into this issue further. It happens in the python3.13-gdb.py file within the following code

    def get_pyop(self):
        try:
            frame = self._gdbframe.read_var('frame')
            frame = PyFramePtr(frame)
            if not frame.is_optimized_out():
                return frame
            cframe = self._gdbframe.read_var('cframe')
            if cframe is None:
                return None
            frame = PyFramePtr(cframe["current_frame"])
            if frame and not frame.is_optimized_out():
                return frame
            return None
        except ValueError:
            return None

With an optimized build, the first if evaluates to false, so that the code tries to read cframe. This variable was removed with #108036 so there needs to be some fix which changes the usage of cframe to the successor

picnixz · 2025-02-10T22:41:23Z

cc @gaogaotiantian (are you the relevant expert here?)

gaogaotiantian · 2025-02-10T22:53:42Z

I have basically 0 knowledge of that file. @markshannon has touched that one a few times I believe but not sure if he is the expert either. He is the expert on the cframe overall however. I can try to take a look if he's too busy.

markshannon · 2025-02-11T10:15:52Z

The reference to cframe is clearly wrong, we should remove that.

It looks like the gdb extension for 3.13 needs debug symbols to work.
The exact behavior of the gdb plugin is neither tested or documented, it is just a "best effort".
The docs say only that a debug build is recommended, not required for debugging, so maybe we should treat this as a bug?

If it worked for 3.12, it would be nice if it worked for 3.13 and 3.14.

kasium added the type-bug An unexpected behavior, bug, or error label Nov 22, 2024

github-actions bot mentioned this issue Dec 1, 2024

Monthly issue metrics report hugovk/test#88

Closed

kasium changed the title ~~python 3.13 gdb extension does not work with optimized build~~ GDB extensions fails with optimized 3.13 due to cframe removal Jan 9, 2025

picnixz mentioned this issue Feb 10, 2025

Add topic-tools label python/core-workflow#567

Closed

picnixz added triaged The issue has been accepted as valid by a triager. 3.13 bugs and security fixes 3.14 bugs and security fixes labels Feb 10, 2025

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GDB extensions fails with optimized 3.13 due to cframe removal #127147

GDB extensions fails with optimized 3.13 due to cframe removal #127147

kasium commented Nov 22, 2024 •

edited by github-actions bot

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kasium commented Jan 9, 2025

picnixz commented Feb 10, 2025

gaogaotiantian commented Feb 10, 2025

markshannon commented Feb 11, 2025

GDB extensions fails with optimized 3.13 due to cframe removal #127147

GDB extensions fails with optimized 3.13 due to cframe removal #127147

Comments

kasium commented Nov 22, 2024 • edited by github-actions bot Loading

Bug report

Bug description:

CPython versions tested on:

Operating systems tested on:

kasium commented Jan 9, 2025

picnixz commented Feb 10, 2025

gaogaotiantian commented Feb 10, 2025

markshannon commented Feb 11, 2025

kasium commented Nov 22, 2024 •

edited by github-actions bot

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