From 7f51171a0e1dbb2908d4c098445facdf9a2b4753 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Thu, 13 Oct 2022 13:34:55 +0200 Subject: [PATCH] gh-98178: syslog() is not thread-safe on macOS (GH-98213) On macOS, fix a crash in syslog.syslog() in multi-threaded applications. On macOS, the libc syslog() function is not thread-safe, so syslog.syslog() no longer releases the GIL to call it. (cherry picked from commit d4b91663857e85eab1f309cacec4d27b5f6657ec) Co-authored-by: Victor Stinner --- .../Library/2022-10-12-10-00-40.gh-issue-98178.hspH51.rst | 4 ++++ Modules/syslogmodule.c | 5 +++++ 2 files changed, 9 insertions(+) create mode 100644 Misc/NEWS.d/next/Library/2022-10-12-10-00-40.gh-issue-98178.hspH51.rst diff --git a/Misc/NEWS.d/next/Library/2022-10-12-10-00-40.gh-issue-98178.hspH51.rst b/Misc/NEWS.d/next/Library/2022-10-12-10-00-40.gh-issue-98178.hspH51.rst new file mode 100644 index 00000000000000..833a6e6bb3f775 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-10-12-10-00-40.gh-issue-98178.hspH51.rst @@ -0,0 +1,4 @@ +On macOS, fix a crash in :func:`syslog.syslog` in multi-threaded applications. +On macOS, the libc ``syslog()`` function is not thread-safe, so +:func:`syslog.syslog` no longer releases the GIL to call it. Patch by Victor +Stinner. diff --git a/Modules/syslogmodule.c b/Modules/syslogmodule.c index bfa2ca2b653bef..8adbe2142d26b3 100644 --- a/Modules/syslogmodule.c +++ b/Modules/syslogmodule.c @@ -207,9 +207,14 @@ syslog_syslog(PyObject * self, PyObject * args) */ PyObject *ident = S_ident_o; Py_XINCREF(ident); +#ifdef __APPLE__ + // gh-98178: On macOS, libc syslog() is not thread-safe + syslog(priority, "%s", message); +#else Py_BEGIN_ALLOW_THREADS; syslog(priority, "%s", message); Py_END_ALLOW_THREADS; +#endif Py_XDECREF(ident); Py_RETURN_NONE; }