classification
Title: Core interpreter should be linked with libgcc_s.so on Linux
Type: crash Stage:
Components: Interpreter Core Versions:
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: zwol
Priority: normal Keywords:

Created on 2019-06-25 01:09 by zwol, last changed 2019-06-25 01:09 by zwol.

Messages (1)
msg346468 - (view) Author: Zack Weinberg (zwol) * Date: 2019-06-25 01:09
There are several existing issues (e.g. #18748 and #35866) where at least part of the problem is that GNU libc tried to dlopen() `libgcc_s.so` at a moment when that's not safe, e.g. during thread or process shutdown.  This converts a recoverable error into a deadlock or crash.

This is arguably a bug in glibc, but Python can easily work around it by linking the core interpreter (the `python` executable and/or `libpython.so`) with libgcc_s at build time (`-lgcc_s`) on Linux.  It will then be loaded already if and when it's needed, and glibc won't try to load it on demand.

In order for this to be 100% reliable, it needs to be at least theoretically possible for code within the interpreter to call a function defined in libgcc_s.so. `_Unwind_Backtrace` is probably the most practical option.  (See https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib--unwind-backtrace.html .)
History
Date User Action Args
2019-06-25 01:09:57zwolcreate