From 522799a05e3e820339718151ac055af6d864d463 Mon Sep 17 00:00:00 2001 From: ChuBoning <102216855+ChuBoning@users.noreply.github.com> Date: Thu, 5 Sep 2024 01:14:59 +0800 Subject: [PATCH] [3.11]GH-112275: Fix HEAD_LOCK deadlock in child process after fork (#112336) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit HEAD_LOCK is called from _PyEval_ReInitThreads->_PyThreadState_DeleteExcept before _PyRuntimeState_ReInitThreads reinit runtime->interpreters.mutex which might be locked before fork. Co-authored-by: Łukasz Langa --- .../2024-09-04-18-20-11.gh-issue-112275.W_iMiB.rst | 3 +++ Modules/posixmodule.c | 10 +++++----- 2 files changed, 8 insertions(+), 5 deletions(-) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2024-09-04-18-20-11.gh-issue-112275.W_iMiB.rst diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-09-04-18-20-11.gh-issue-112275.W_iMiB.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-09-04-18-20-11.gh-issue-112275.W_iMiB.rst new file mode 100644 index 00000000000000..d663be1867ed3d --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-09-04-18-20-11.gh-issue-112275.W_iMiB.rst @@ -0,0 +1,3 @@ +A deadlock involving ``pystate.c``'s ``HEAD_LOCK`` in ``posixmodule.c`` +at fork is now fixed. Patch by ChuBoning based on previous Python 3.12 +fix by Victor Stinner. diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c index 46859dab35c500..6fb2fc8ce250c1 100644 --- a/Modules/posixmodule.c +++ b/Modules/posixmodule.c @@ -603,6 +603,11 @@ PyOS_AfterFork_Child(void) goto fatal_error; } + status = _PyRuntimeState_ReInitThreads(runtime); + if (_PyStatus_EXCEPTION(status)) { + goto fatal_error; + } + PyThreadState *tstate = _PyThreadState_GET(); _Py_EnsureTstateNotNULL(tstate); @@ -622,11 +627,6 @@ PyOS_AfterFork_Child(void) _PySignal_AfterFork(); - status = _PyRuntimeState_ReInitThreads(runtime); - if (_PyStatus_EXCEPTION(status)) { - goto fatal_error; - } - status = _PyInterpreterState_DeleteExceptMain(runtime); if (_PyStatus_EXCEPTION(status)) { goto fatal_error;