https://github.com/python/cpython/commit/eddc8c0a1d274ff6393c6fa233e535360c0dd07b
commit: eddc8c0a1d274ff6393c6fa233e535360c0dd07b
branch: main
author: Alper <[email protected]>
committer: mpage <[email protected]>
date: 2025-07-17T09:16:01-07:00
summary:
gh-116738: Make pwd module thread-safe (#136695)
Make the pwd module functions getpwuid(), getpwnam(), and getpwall()
thread-safe. These changes apply to scenarios where the GIL is disabled or in
subinterpreter use cases.
files:
A Lib/test/test_free_threading/test_pwd.py
A
Misc/NEWS.d/next/Core_and_Builtins/2025-07-15-10-03-57.gh-issue-116738.oFttKl.rst
M Modules/clinic/pwdmodule.c.h
M Modules/pwdmodule.c
M Tools/c-analyzer/cpython/ignored.tsv
diff --git a/Lib/test/test_free_threading/test_pwd.py
b/Lib/test/test_free_threading/test_pwd.py
new file mode 100644
index 00000000000000..58ab22bae39673
--- /dev/null
+++ b/Lib/test/test_free_threading/test_pwd.py
@@ -0,0 +1,33 @@
+import unittest
+
+from test.support import threading_helper
+from test.support.threading_helper import run_concurrently
+
+from test import test_pwd
+
+
+NTHREADS = 10
+
+
+@threading_helper.requires_working_threading()
+class TestPwd(unittest.TestCase):
+ def setUp(self):
+ self.test_pwd = test_pwd.PwdTest()
+
+ def test_racing_test_values(self):
+ # test_pwd.test_values() calls pwd.getpwall() and checks the entries
+ run_concurrently(
+ worker_func=self.test_pwd.test_values, nthreads=NTHREADS
+ )
+
+ def test_racing_test_values_extended(self):
+ # test_pwd.test_values_extended() calls pwd.getpwall(), pwd.getpwnam(),
+ # pwd.getpwduid() and checks the entries
+ run_concurrently(
+ worker_func=self.test_pwd.test_values_extended,
+ nthreads=NTHREADS,
+ )
+
+
+if __name__ == "__main__":
+ unittest.main()
diff --git
a/Misc/NEWS.d/next/Core_and_Builtins/2025-07-15-10-03-57.gh-issue-116738.oFttKl.rst
b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-15-10-03-57.gh-issue-116738.oFttKl.rst
new file mode 100644
index 00000000000000..07d8b45fb7fbf1
--- /dev/null
+++
b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-15-10-03-57.gh-issue-116738.oFttKl.rst
@@ -0,0 +1 @@
+Make functions in :mod:`pwd` thread-safe on the :term:`free threaded <free
threading>` build.
diff --git a/Modules/clinic/pwdmodule.c.h b/Modules/clinic/pwdmodule.c.h
index 365d99aab1dd22..43d4825031c7e6 100644
--- a/Modules/clinic/pwdmodule.c.h
+++ b/Modules/clinic/pwdmodule.c.h
@@ -2,6 +2,8 @@
preserve
[clinic start generated code]*/
+#include "pycore_modsupport.h" // _PyArg_BadArgument()
+
PyDoc_STRVAR(pwd_getpwuid__doc__,
"getpwuid($module, uidobj, /)\n"
"--\n"
@@ -34,7 +36,7 @@ pwd_getpwnam(PyObject *module, PyObject *arg)
PyObject *name;
if (!PyUnicode_Check(arg)) {
- PyErr_Format(PyExc_TypeError, "getpwnam() argument must be str, not
%T", arg);
+ _PyArg_BadArgument("getpwnam", "argument", "str", arg);
goto exit;
}
name = arg;
@@ -71,4 +73,4 @@ pwd_getpwall(PyObject *module, PyObject *Py_UNUSED(ignored))
#ifndef PWD_GETPWALL_METHODDEF
#define PWD_GETPWALL_METHODDEF
#endif /* !defined(PWD_GETPWALL_METHODDEF) */
-/*[clinic end generated code: output=dac88d500f6d6f49 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=5a8fb12939ff4ea3 input=a9049054013a1b77]*/
diff --git a/Modules/pwdmodule.c b/Modules/pwdmodule.c
index c5a8cead19a773..ac1a04a54edd60 100644
--- a/Modules/pwdmodule.c
+++ b/Modules/pwdmodule.c
@@ -1,12 +1,6 @@
/* UNIX password file access module */
-// Need limited C API version 3.13 for PyMem_RawRealloc()
-#include "pyconfig.h" // Py_GIL_DISABLED
-#ifndef Py_GIL_DISABLED
-# define Py_LIMITED_API 0x030d0000
-#endif
-
#include "Python.h"
#include "posixmodule.h"
@@ -69,6 +63,11 @@ get_pwd_state(PyObject *module)
static struct PyModuleDef pwdmodule;
+/* Mutex to protect calls to getpwuid(), getpwnam(), and getpwent().
+ * These functions return pointer to static data structure, which
+ * may be overwritten by any subsequent calls. */
+static PyMutex pwd_db_mutex = {0};
+
#define DEFAULT_BUFFER_SIZE 1024
static PyObject *
@@ -182,9 +181,15 @@ pwd_getpwuid(PyObject *module, PyObject *uidobj)
Py_END_ALLOW_THREADS
#else
+ PyMutex_Lock(&pwd_db_mutex);
+ // The getpwuid() function is not required to be thread-safe.
+ // https://pubs.opengroup.org/onlinepubs/009604499/functions/getpwuid.html
p = getpwuid(uid);
#endif
if (p == NULL) {
+#ifndef HAVE_GETPWUID_R
+ PyMutex_Unlock(&pwd_db_mutex);
+#endif
PyMem_RawFree(buf);
if (nomem == 1) {
return PyErr_NoMemory();
@@ -200,6 +205,8 @@ pwd_getpwuid(PyObject *module, PyObject *uidobj)
retval = mkpwent(module, p);
#ifdef HAVE_GETPWUID_R
PyMem_RawFree(buf);
+#else
+ PyMutex_Unlock(&pwd_db_mutex);
#endif
return retval;
}
@@ -265,9 +272,15 @@ pwd_getpwnam_impl(PyObject *module, PyObject *name)
Py_END_ALLOW_THREADS
#else
+ PyMutex_Lock(&pwd_db_mutex);
+ // The getpwnam() function is not required to be thread-safe.
+ // https://pubs.opengroup.org/onlinepubs/009604599/functions/getpwnam.html
p = getpwnam(name_chars);
#endif
if (p == NULL) {
+#ifndef HAVE_GETPWNAM_R
+ PyMutex_Unlock(&pwd_db_mutex);
+#endif
if (nomem == 1) {
PyErr_NoMemory();
}
@@ -278,6 +291,9 @@ pwd_getpwnam_impl(PyObject *module, PyObject *name)
goto out;
}
retval = mkpwent(module, p);
+#ifndef HAVE_GETPWNAM_R
+ PyMutex_Unlock(&pwd_db_mutex);
+#endif
out:
PyMem_RawFree(buf);
Py_DECREF(bytes);
@@ -302,12 +318,12 @@ pwd_getpwall_impl(PyObject *module)
if ((d = PyList_New(0)) == NULL)
return NULL;
-#ifdef Py_GIL_DISABLED
- static PyMutex getpwall_mutex = {0};
- PyMutex_Lock(&getpwall_mutex);
-#endif
+ PyMutex_Lock(&pwd_db_mutex);
int failure = 0;
PyObject *v = NULL;
+ // The setpwent(), getpwent() and endpwent() functions are not required to
+ // be thread-safe.
+ // https://pubs.opengroup.org/onlinepubs/009696799/functions/setpwent.html
setpwent();
while ((p = getpwent()) != NULL) {
v = mkpwent(module, p);
@@ -321,9 +337,7 @@ pwd_getpwall_impl(PyObject *module)
done:
endpwent();
-#ifdef Py_GIL_DISABLED
- PyMutex_Unlock(&getpwall_mutex);
-#endif
+ PyMutex_Unlock(&pwd_db_mutex);
if (failure) {
Py_XDECREF(v);
Py_CLEAR(d);
diff --git a/Tools/c-analyzer/cpython/ignored.tsv
b/Tools/c-analyzer/cpython/ignored.tsv
index 64a9f11a944176..dc626e4bea0f59 100644
--- a/Tools/c-analyzer/cpython/ignored.tsv
+++ b/Tools/c-analyzer/cpython/ignored.tsv
@@ -168,6 +168,7 @@ Python/sysmodule.c - _preinit_xoptions -
Modules/faulthandler.c faulthandler_dump_traceback reentrant -
Modules/faulthandler.c faulthandler_dump_c_stack reentrant -
Modules/grpmodule.c - group_db_mutex -
+Modules/pwdmodule.c - pwd_db_mutex -
Python/pylifecycle.c _Py_FatalErrorFormat reentrant -
Python/pylifecycle.c fatal_error reentrant -
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