diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 66cb63daca02ae..bc364e5704ecc7 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1297,6 +1297,10 @@ def testGetServBy(self):
         self.assertRaises(OverflowError, socket.getservbyport, -1)
         self.assertRaises(OverflowError, socket.getservbyport, 65536)
 
+    def testGetProtoByName(self):
+        self.assertEqual(socket.getprotobyname('tcp'), 6)
+        self.assertRaises(OSError, socket.getprotobyname, 'non-existent proto')
+
     def testDefaultTimeout(self):
         # Testing default timeout
         # The default timeout should initially be None
diff --git a/Misc/NEWS.d/next/Library/2025-04-17-00-14-41.gh-issue-127081.aEM3Hk.rst b/Misc/NEWS.d/next/Library/2025-04-17-00-14-41.gh-issue-127081.aEM3Hk.rst
new file mode 100644
index 00000000000000..08b44d3fb6432b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-04-17-00-14-41.gh-issue-127081.aEM3Hk.rst
@@ -0,0 +1,5 @@
+Fix libc thread safety issues with :mod:`socket` (replace ``getservbyname``,
+``getservbyport``, ``getprotobyname`` with ``*_r`` re-entrant versions),
+:mod:`pwd` (lock access to ``getpwall``), :mod:`dbm` (perform stateful
+operations in critical sections), and :mod:`os` (replace ``getlogin`` with
+``getlogin_r`` re-entrant version).
diff --git a/Modules/_dbmmodule.c b/Modules/_dbmmodule.c
index cc65cbd98d71dc..b293b9ee0b9f6a 100644
--- a/Modules/_dbmmodule.c
+++ b/Modules/_dbmmodule.c
@@ -68,6 +68,7 @@ typedef struct {
 
 #include "clinic/_dbmmodule.c.h"
 
+/* NOTE: Must be used within a critical section! */
 #define check_dbmobject_open(v, err)                                \
     if ((v)->di_dbm == NULL) {                                      \
         PyErr_SetString(err, "DBM object has already been closed"); \
@@ -118,12 +119,15 @@ dbm_dealloc(PyObject *self)
 static Py_ssize_t
 dbm_length(PyObject *self)
 {
+    Py_ssize_t result = -1;
     dbmobject *dp = dbmobject_CAST(self);
     _dbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
     assert(state != NULL);
+
+    Py_BEGIN_CRITICAL_SECTION(self);
     if (dp->di_dbm == NULL) {
              PyErr_SetString(state->dbm_error, "DBM object has already been closed");
-             return -1;
+             goto done;
     }
     if ( dp->di_size < 0 ) {
         datum key;
@@ -135,39 +139,51 @@ dbm_length(PyObject *self)
             size++;
         dp->di_size = size;
     }
-    return dp->di_size;
+    result = dp->di_size;
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 static int
 dbm_bool(PyObject *self)
 {
+    int result;
     dbmobject *dp = dbmobject_CAST(self);
     _dbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
     assert(state != NULL);
 
+    Py_BEGIN_CRITICAL_SECTION(self);
     if (dp->di_dbm == NULL) {
         PyErr_SetString(state->dbm_error, "DBM object has already been closed");
-        return -1;
+        result = -1;
+        goto done;
     }
 
     if (dp->di_size > 0) {
         /* Known non-zero size. */
-        return 1;
+        result = 1;
+        goto done;
     }
     if (dp->di_size == 0) {
         /* Known zero size. */
-        return 0;
+        result = 0;
+        goto done;
     }
 
     /* Unknown size.  Ensure DBM object has an entry. */
     datum key = dbm_firstkey(dp->di_dbm);
     if (key.dptr == NULL) {
         /* Empty. Cache this fact. */
-        dp->di_size = 0;
-        return 0;
+        result = dp->di_size = 0;
+        goto done;
     }
+
     /* Non-empty. Don't cache the length since we don't know. */
-    return 1;
+    result = 1;
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 static PyObject *
@@ -175,26 +191,35 @@ dbm_subscript(PyObject *self, PyObject *key)
 {
     datum drec, krec;
     Py_ssize_t tmp_size;
+    PyObject *result = NULL;
     dbmobject *dp = dbmobject_CAST(self);
     _dbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
     assert(state != NULL);
     if (!PyArg_Parse(key, "s#", &krec.dptr, &tmp_size)) {
         return NULL;
     }
-
     krec.dsize = tmp_size;
-    check_dbmobject_open(dp, state->dbm_error);
+
+    Py_BEGIN_CRITICAL_SECTION(self);
+    /* Can't use the macro here as it returns. */
+    if (dp->di_dbm == NULL) {
+        PyErr_SetString(state->dbm_error, "DBM object has already been closed");
+        goto done;
+    }
     drec = dbm_fetch(dp->di_dbm, krec);
     if ( drec.dptr == 0 ) {
         PyErr_SetObject(PyExc_KeyError, key);
-        return NULL;
+        goto done;
     }
     if ( dbm_error(dp->di_dbm) ) {
         dbm_clearerr(dp->di_dbm);
         PyErr_SetString(state->dbm_error, "");
-        return NULL;
+        goto done;
     }
-    return PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
+    result = PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 static int
@@ -202,6 +227,7 @@ dbm_ass_sub(PyObject *self, PyObject *v, PyObject *w)
 {
     datum krec, drec;
     Py_ssize_t tmp_size;
+    int result = -1;
     dbmobject *dp = dbmobject_CAST(self);
 
     if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
@@ -212,10 +238,13 @@ dbm_ass_sub(PyObject *self, PyObject *v, PyObject *w)
     _dbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
     assert(state != NULL);
     krec.dsize = tmp_size;
+
+    Py_BEGIN_CRITICAL_SECTION(self);
     if (dp->di_dbm == NULL) {
-             PyErr_SetString(state->dbm_error, "DBM object has already been closed");
-             return -1;
+        PyErr_SetString(state->dbm_error, "DBM object has already been closed");
+        goto done;
     }
+
     dp->di_size = -1;
     if (w == NULL) {
         if ( dbm_delete(dp->di_dbm, krec) < 0 ) {
@@ -228,31 +257,36 @@ dbm_ass_sub(PyObject *self, PyObject *v, PyObject *w)
             else {
                 PyErr_SetString(state->dbm_error, "cannot delete item from database");
             }
-            return -1;
+            goto done;
         }
     } else {
         if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
             PyErr_SetString(PyExc_TypeError,
                  "dbm mappings have bytes or string elements only");
-            return -1;
+            goto done;
         }
         drec.dsize = tmp_size;
         if ( dbm_store(dp->di_dbm, krec, drec, DBM_REPLACE) < 0 ) {
             dbm_clearerr(dp->di_dbm);
             PyErr_SetString(state->dbm_error,
                             "cannot add item to database");
-            return -1;
+            goto done;
         }
     }
     if ( dbm_error(dp->di_dbm) ) {
         dbm_clearerr(dp->di_dbm);
         PyErr_SetString(state->dbm_error, "");
-        return -1;
+        goto done;
     }
-    return 0;
+
+    result = 0;
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 /*[clinic input]
+@critical_section
 _dbm.dbm.close
 
 Close the database.
@@ -260,7 +294,7 @@ Close the database.
 
 static PyObject *
 _dbm_dbm_close_impl(dbmobject *self)
-/*[clinic end generated code: output=c8dc5b6709600b86 input=046db72377d51be8]*/
+/*[clinic end generated code: output=c8dc5b6709600b86 input=4a94f79facbc28ca]*/
 {
     if (self->di_dbm) {
         dbm_close(self->di_dbm);
@@ -270,6 +304,7 @@ _dbm_dbm_close_impl(dbmobject *self)
 }
 
 /*[clinic input]
+@critical_section
 _dbm.dbm.keys
 
     cls: defining_class
@@ -279,7 +314,7 @@ Return a list of all keys in the database.
 
 static PyObject *
 _dbm_dbm_keys_impl(dbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=f2a593b3038e5996 input=d3706a28fc051097]*/
+/*[clinic end generated code: output=f2a593b3038e5996 input=6ddefeadf2a80156]*/
 {
     PyObject *v, *item;
     datum key;
@@ -315,35 +350,42 @@ dbm_contains(PyObject *self, PyObject *arg)
     dbmobject *dp = dbmobject_CAST(self);
     datum key, val;
     Py_ssize_t size;
+    int result = -1;
 
     _dbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
     assert(state != NULL);
+
+    Py_BEGIN_CRITICAL_SECTION(self);
     if ((dp)->di_dbm == NULL) {
         PyErr_SetString(state->dbm_error,
                         "DBM object has already been closed");
-         return -1;
+         goto done;
     }
     if (PyUnicode_Check(arg)) {
         key.dptr = (char *)PyUnicode_AsUTF8AndSize(arg, &size);
         key.dsize = size;
         if (key.dptr == NULL)
-            return -1;
+            goto done;
     }
     else if (!PyBytes_Check(arg)) {
         PyErr_Format(PyExc_TypeError,
                      "dbm key must be bytes or string, not %.100s",
                      Py_TYPE(arg)->tp_name);
-        return -1;
+        goto done;
     }
     else {
         key.dptr = PyBytes_AS_STRING(arg);
         key.dsize = PyBytes_GET_SIZE(arg);
     }
     val = dbm_fetch(dp->di_dbm, key);
-    return val.dptr != NULL;
+    result = val.dptr != NULL;
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 /*[clinic input]
+@critical_section
 _dbm.dbm.get
     cls: defining_class
     key: str(accept={str, robuffer}, zeroes=True)
@@ -356,7 +398,7 @@ Return the value for key if present, otherwise default.
 static PyObject *
 _dbm_dbm_get_impl(dbmobject *self, PyTypeObject *cls, const char *key,
                   Py_ssize_t key_length, PyObject *default_value)
-/*[clinic end generated code: output=b4e55f8b6d482bc4 input=66b993b8349fa8c1]*/
+/*[clinic end generated code: output=b4e55f8b6d482bc4 input=1d88a22bb5e55202]*/
 {
     datum dbm_key, val;
     _dbm_state *state = PyType_GetModuleState(cls);
@@ -373,6 +415,7 @@ _dbm_dbm_get_impl(dbmobject *self, PyTypeObject *cls, const char *key,
 }
 
 /*[clinic input]
+@critical_section
 _dbm.dbm.setdefault
     cls: defining_class
     key: str(accept={str, robuffer}, zeroes=True)
@@ -387,7 +430,7 @@ If key is not in the database, it is inserted with default as the value.
 static PyObject *
 _dbm_dbm_setdefault_impl(dbmobject *self, PyTypeObject *cls, const char *key,
                          Py_ssize_t key_length, PyObject *default_value)
-/*[clinic end generated code: output=9c2f6ea6d0fb576c input=126a3ff15c5f8232]*/
+/*[clinic end generated code: output=9c2f6ea6d0fb576c input=c01510ef7571e13b]*/
 {
     datum dbm_key, val;
     Py_ssize_t tmp_size;
@@ -427,6 +470,7 @@ _dbm_dbm_setdefault_impl(dbmobject *self, PyTypeObject *cls, const char *key,
 }
 
 /*[clinic input]
+@critical_section
 _dbm.dbm.clear
     cls: defining_class
     /
@@ -436,7 +480,7 @@ Remove all items from the database.
 
 static PyObject *
 _dbm_dbm_clear_impl(dbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=8d126b9e1d01a434 input=43aa6ca1acb7f5f5]*/
+/*[clinic end generated code: output=8d126b9e1d01a434 input=a1aa5d99adfb9656]*/
 {
     _dbm_state *state = PyType_GetModuleState(cls);
     assert(state != NULL);
diff --git a/Modules/_gdbmmodule.c b/Modules/_gdbmmodule.c
index ab2ebdba9249bf..7f9afabf652b88 100644
--- a/Modules/_gdbmmodule.c
+++ b/Modules/_gdbmmodule.c
@@ -80,6 +80,7 @@ typedef struct {
 
 #include "clinic/_gdbmmodule.c.h"
 
+/* NOTE: Must be used within a critical section! */
 #define check_gdbmobject_open(v, err)                                 \
     if ((v)->di_dbm == NULL) {                                       \
         PyErr_SetString(err, "GDBM object has already been closed"); \
@@ -144,8 +145,10 @@ gdbm_dealloc(PyObject *op)
 static Py_ssize_t
 gdbm_length(PyObject *op)
 {
+    Py_ssize_t result = -1;
     gdbmobject *dp = _gdbmobject_CAST(op);
     _gdbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
+    Py_BEGIN_CRITICAL_SECTION(op);
     if (dp->di_dbm == NULL) {
         PyErr_SetString(state->gdbm_error, "GDBM object has already been closed");
         return -1;
@@ -161,11 +164,11 @@ gdbm_length(PyObject *op)
             else {
                 set_gdbm_error(state, "gdbm_count() error");
             }
-            return -1;
+            goto done;
         }
         if (count > PY_SSIZE_T_MAX) {
             PyErr_SetString(PyExc_OverflowError, "count exceeds PY_SSIZE_T_MAX");
-            return -1;
+            goto done;
         }
         dp->di_size = count;
 #else
@@ -185,37 +188,50 @@ gdbm_length(PyObject *op)
         dp->di_size = size;
 #endif
     }
-    return dp->di_size;
+    result = dp->di_size;
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 static int
 gdbm_bool(PyObject *op)
 {
+    int result;
     gdbmobject *dp = _gdbmobject_CAST(op);
     _gdbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
+
+    Py_BEGIN_CRITICAL_SECTION(op);
     if (dp->di_dbm == NULL) {
         PyErr_SetString(state->gdbm_error, "GDBM object has already been closed");
-        return -1;
+        result = -1;
+        goto done;
     }
     if (dp->di_size > 0) {
         /* Known non-zero size. */
-        return 1;
+        result = 1;
+        goto done;
     }
     if (dp->di_size == 0) {
         /* Known zero size. */
-        return 0;
+        result = 0;
+        goto done;
     }
     /* Unknown size.  Ensure DBM object has an entry. */
     datum key = gdbm_firstkey(dp->di_dbm);
     if (key.dptr == NULL) {
         /* Empty. Cache this fact. */
-        dp->di_size = 0;
-        return 0;
+        result = dp->di_size = 0;
+        goto done;
     }
 
     /* Non-empty. Don't cache the length since we don't know. */
     free(key.dptr);
-    return 1;
+    result = 1;
+
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 // Wrapper function for PyArg_Parse(o, "s#", &d.dptr, &d.size).
@@ -242,7 +258,7 @@ parse_datum(PyObject *o, datum *d, const char *failmsg)
 static PyObject *
 gdbm_subscript(PyObject *op, PyObject *key)
 {
-    PyObject *v;
+    PyObject *v = NULL;
     datum drec, krec;
     gdbmobject *dp = _gdbmobject_CAST(op);
     _gdbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
@@ -250,18 +266,22 @@ gdbm_subscript(PyObject *op, PyObject *key)
     if (!parse_datum(key, &krec, NULL)) {
         return NULL;
     }
+
+    Py_BEGIN_CRITICAL_SECTION(op);
     if (dp->di_dbm == NULL) {
         PyErr_SetString(state->gdbm_error,
                         "GDBM object has already been closed");
-        return NULL;
+        goto done;
     }
     drec = gdbm_fetch(dp->di_dbm, krec);
     if (drec.dptr == 0) {
         PyErr_SetObject(PyExc_KeyError, key);
-        return NULL;
+        goto done;
     }
     v = PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
     free(drec.dptr);
+done:;
+    Py_END_CRITICAL_SECTION();
     return v;
 }
 
@@ -294,16 +314,19 @@ gdbm_ass_sub(PyObject *op, PyObject *v, PyObject *w)
 {
     datum krec, drec;
     const char *failmsg = "gdbm mappings have bytes or string indices only";
+    int result = -1;
     gdbmobject *dp = _gdbmobject_CAST(op);
     _gdbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
 
     if (!parse_datum(v, &krec, failmsg)) {
         return -1;
     }
+
+    Py_BEGIN_CRITICAL_SECTION(op);
     if (dp->di_dbm == NULL) {
         PyErr_SetString(state->gdbm_error,
                         "GDBM object has already been closed");
-        return -1;
+        goto done;
     }
     dp->di_size = -1;
     if (w == NULL) {
@@ -314,12 +337,12 @@ gdbm_ass_sub(PyObject *op, PyObject *v, PyObject *w)
             else {
                 set_gdbm_error(state, "gdbm_delete() error");
             }
-            return -1;
+            goto done;
         }
     }
     else {
         if (!parse_datum(w, &drec, failmsg)) {
-            return -1;
+            goto done;
         }
         errno = 0;
         if (gdbm_store(dp->di_dbm, krec, drec, GDBM_REPLACE) < 0) {
@@ -329,13 +352,18 @@ gdbm_ass_sub(PyObject *op, PyObject *v, PyObject *w)
             else {
                 set_gdbm_error(state, "gdbm_store() error");
             }
-            return -1;
+            goto done;
         }
     }
-    return 0;
+    result = 0;
+
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.setdefault
 
     key: object
@@ -348,7 +376,7 @@ Get value for key, or set it to default and return default if not present.
 static PyObject *
 _gdbm_gdbm_setdefault_impl(gdbmobject *self, PyObject *key,
                            PyObject *default_value)
-/*[clinic end generated code: output=f3246e880509f142 input=0db46b69e9680171]*/
+/*[clinic end generated code: output=f3246e880509f142 input=854374cd81ab51b6]*/
 {
     PyObject *res;
 
@@ -363,6 +391,7 @@ _gdbm_gdbm_setdefault_impl(gdbmobject *self, PyObject *key,
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.close
 
 Close the database.
@@ -370,7 +399,7 @@ Close the database.
 
 static PyObject *
 _gdbm_gdbm_close_impl(gdbmobject *self)
-/*[clinic end generated code: output=f5abb4d6bb9e52d5 input=0a203447379b45fd]*/
+/*[clinic end generated code: output=f5abb4d6bb9e52d5 input=56b604f4e77f533d]*/
 {
     if (self->di_dbm) {
         gdbm_close(self->di_dbm);
@@ -381,6 +410,7 @@ _gdbm_gdbm_close_impl(gdbmobject *self)
 
 /* XXX Should return a set or a set view */
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.keys
 
     cls: defining_class
@@ -390,7 +420,7 @@ Get a list of all keys in the database.
 
 static PyObject *
 _gdbm_gdbm_keys_impl(gdbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=c24b824e81404755 input=1428b7c79703d7d5]*/
+/*[clinic end generated code: output=c24b824e81404755 input=785988b1ea8f77e0]*/
 {
     PyObject *v, *item;
     datum key, nextkey;
@@ -437,33 +467,40 @@ gdbm_contains(PyObject *self, PyObject *arg)
     gdbmobject *dp = (gdbmobject *)self;
     datum key;
     Py_ssize_t size;
+    int result = -1;
     _gdbm_state *state = PyType_GetModuleState(Py_TYPE(dp));
 
+    Py_BEGIN_CRITICAL_SECTION(self);
     if ((dp)->di_dbm == NULL) {
         PyErr_SetString(state->gdbm_error,
                         "GDBM object has already been closed");
-        return -1;
+        goto done;
     }
     if (PyUnicode_Check(arg)) {
         key.dptr = (char *)PyUnicode_AsUTF8AndSize(arg, &size);
         key.dsize = size;
         if (key.dptr == NULL)
-            return -1;
+            goto done;
     }
     else if (!PyBytes_Check(arg)) {
         PyErr_Format(PyExc_TypeError,
                      "gdbm key must be bytes or string, not %.100s",
                      Py_TYPE(arg)->tp_name);
-        return -1;
+        goto done;
     }
     else {
         key.dptr = PyBytes_AS_STRING(arg);
         key.dsize = PyBytes_GET_SIZE(arg);
     }
-    return gdbm_exists(dp->di_dbm, key);
+    result = gdbm_exists(dp->di_dbm, key);
+
+done:;
+    Py_END_CRITICAL_SECTION();
+    return result;
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.firstkey
 
     cls: defining_class
@@ -477,7 +514,7 @@ hash values, and won't be sorted by the key values.
 
 static PyObject *
 _gdbm_gdbm_firstkey_impl(gdbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=139275e9c8b60827 input=ed8782a029a5d299]*/
+/*[clinic end generated code: output=139275e9c8b60827 input=aad5a7c886c542f5]*/
 {
     PyObject *v;
     datum key;
@@ -497,6 +534,7 @@ _gdbm_gdbm_firstkey_impl(gdbmobject *self, PyTypeObject *cls)
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.nextkey
 
     cls: defining_class
@@ -517,7 +555,7 @@ to create a list in memory that contains them all:
 static PyObject *
 _gdbm_gdbm_nextkey_impl(gdbmobject *self, PyTypeObject *cls, const char *key,
                         Py_ssize_t key_length)
-/*[clinic end generated code: output=c81a69300ef41766 input=365e297bc0b3db48]*/
+/*[clinic end generated code: output=c81a69300ef41766 input=181f1130d5bfeb1e]*/
 {
     PyObject *v;
     datum dbm_key, nextkey;
@@ -539,6 +577,7 @@ _gdbm_gdbm_nextkey_impl(gdbmobject *self, PyTypeObject *cls, const char *key,
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.reorganize
 
     cls: defining_class
@@ -554,7 +593,7 @@ kept and reused as new (key,value) pairs are added.
 
 static PyObject *
 _gdbm_gdbm_reorganize_impl(gdbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=d77c69e8e3dd644a input=e1359faeef844e46]*/
+/*[clinic end generated code: output=d77c69e8e3dd644a input=3e3ca0d2ea787861]*/
 {
     _gdbm_state *state = PyType_GetModuleState(cls);
     assert(state != NULL);
@@ -573,6 +612,7 @@ _gdbm_gdbm_reorganize_impl(gdbmobject *self, PyTypeObject *cls)
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.sync
 
     cls: defining_class
@@ -585,7 +625,7 @@ any unwritten data to be written to the disk.
 
 static PyObject *
 _gdbm_gdbm_sync_impl(gdbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=bb680a2035c3f592 input=3d749235f79b6f2a]*/
+/*[clinic end generated code: output=bb680a2035c3f592 input=6054385b071d238a]*/
 {
     _gdbm_state *state = PyType_GetModuleState(cls);
     assert(state != NULL);
@@ -595,6 +635,7 @@ _gdbm_gdbm_sync_impl(gdbmobject *self, PyTypeObject *cls)
 }
 
 /*[clinic input]
+@critical_section
 _gdbm.gdbm.clear
     cls: defining_class
     /
@@ -604,7 +645,7 @@ Remove all items from the database.
 
 static PyObject *
 _gdbm_gdbm_clear_impl(gdbmobject *self, PyTypeObject *cls)
-/*[clinic end generated code: output=673577c573318661 input=34136d52fcdd4210]*/
+/*[clinic end generated code: output=673577c573318661 input=b17467adfe62f23d]*/
 {
     _gdbm_state *state = PyType_GetModuleState(cls);
     assert(state != NULL);
diff --git a/Modules/clinic/_dbmmodule.c.h b/Modules/clinic/_dbmmodule.c.h
index 5e503194408776..091ce9edc43d4b 100644
--- a/Modules/clinic/_dbmmodule.c.h
+++ b/Modules/clinic/_dbmmodule.c.h
@@ -5,6 +5,7 @@ preserve
 #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
 #  include "pycore_runtime.h"     // _Py_SINGLETON()
 #endif
+#include "pycore_critical_section.h"// Py_BEGIN_CRITICAL_SECTION()
 #include "pycore_modsupport.h"    // _PyArg_UnpackKeywords()
 
 PyDoc_STRVAR(_dbm_dbm_close__doc__,
@@ -22,7 +23,13 @@ _dbm_dbm_close_impl(dbmobject *self);
 static PyObject *
 _dbm_dbm_close(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
-    return _dbm_dbm_close_impl((dbmobject *)self);
+    PyObject *return_value = NULL;
+
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _dbm_dbm_close_impl((dbmobject *)self);
+    Py_END_CRITICAL_SECTION();
+
+    return return_value;
 }
 
 PyDoc_STRVAR(_dbm_dbm_keys__doc__,
@@ -40,11 +47,18 @@ _dbm_dbm_keys_impl(dbmobject *self, PyTypeObject *cls);
 static PyObject *
 _dbm_dbm_keys(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "keys() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _dbm_dbm_keys_impl((dbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _dbm_dbm_keys_impl((dbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(_dbm_dbm_get__doc__,
@@ -85,7 +99,9 @@ _dbm_dbm_get(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_
         &key, &key_length, &default_value)) {
         goto exit;
     }
+    Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _dbm_dbm_get_impl((dbmobject *)self, cls, key, key_length, default_value);
+    Py_END_CRITICAL_SECTION();
 
 exit:
     return return_value;
@@ -131,7 +147,9 @@ _dbm_dbm_setdefault(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py
         &key, &key_length, &default_value)) {
         goto exit;
     }
+    Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _dbm_dbm_setdefault_impl((dbmobject *)self, cls, key, key_length, default_value);
+    Py_END_CRITICAL_SECTION();
 
 exit:
     return return_value;
@@ -152,11 +170,18 @@ _dbm_dbm_clear_impl(dbmobject *self, PyTypeObject *cls);
 static PyObject *
 _dbm_dbm_clear(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "clear() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _dbm_dbm_clear_impl((dbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _dbm_dbm_clear_impl((dbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(dbmopen__doc__,
@@ -221,4 +246,4 @@ dbmopen(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=3b456118f231b160 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=279511ea7cda38dd input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_gdbmmodule.c.h b/Modules/clinic/_gdbmmodule.c.h
index 00950f18e53541..6fd6aa3da50335 100644
--- a/Modules/clinic/_gdbmmodule.c.h
+++ b/Modules/clinic/_gdbmmodule.c.h
@@ -5,6 +5,7 @@ preserve
 #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
 #  include "pycore_runtime.h"     // _Py_SINGLETON()
 #endif
+#include "pycore_critical_section.h"// Py_BEGIN_CRITICAL_SECTION()
 #include "pycore_modsupport.h"    // _PyArg_CheckPositional()
 
 PyDoc_STRVAR(_gdbm_gdbm_get__doc__,
@@ -70,7 +71,9 @@ _gdbm_gdbm_setdefault(PyObject *self, PyObject *const *args, Py_ssize_t nargs)
     }
     default_value = args[1];
 skip_optional:
+    Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _gdbm_gdbm_setdefault_impl((gdbmobject *)self, key, default_value);
+    Py_END_CRITICAL_SECTION();
 
 exit:
     return return_value;
@@ -91,7 +94,13 @@ _gdbm_gdbm_close_impl(gdbmobject *self);
 static PyObject *
 _gdbm_gdbm_close(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
-    return _gdbm_gdbm_close_impl((gdbmobject *)self);
+    PyObject *return_value = NULL;
+
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _gdbm_gdbm_close_impl((gdbmobject *)self);
+    Py_END_CRITICAL_SECTION();
+
+    return return_value;
 }
 
 PyDoc_STRVAR(_gdbm_gdbm_keys__doc__,
@@ -109,11 +118,18 @@ _gdbm_gdbm_keys_impl(gdbmobject *self, PyTypeObject *cls);
 static PyObject *
 _gdbm_gdbm_keys(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "keys() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _gdbm_gdbm_keys_impl((gdbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _gdbm_gdbm_keys_impl((gdbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(_gdbm_gdbm_firstkey__doc__,
@@ -135,11 +151,18 @@ _gdbm_gdbm_firstkey_impl(gdbmobject *self, PyTypeObject *cls);
 static PyObject *
 _gdbm_gdbm_firstkey(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "firstkey() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _gdbm_gdbm_firstkey_impl((gdbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _gdbm_gdbm_firstkey_impl((gdbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(_gdbm_gdbm_nextkey__doc__,
@@ -187,7 +210,9 @@ _gdbm_gdbm_nextkey(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_
         &key, &key_length)) {
         goto exit;
     }
+    Py_BEGIN_CRITICAL_SECTION(self);
     return_value = _gdbm_gdbm_nextkey_impl((gdbmobject *)self, cls, key, key_length);
+    Py_END_CRITICAL_SECTION();
 
 exit:
     return return_value;
@@ -214,11 +239,18 @@ _gdbm_gdbm_reorganize_impl(gdbmobject *self, PyTypeObject *cls);
 static PyObject *
 _gdbm_gdbm_reorganize(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "reorganize() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _gdbm_gdbm_reorganize_impl((gdbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _gdbm_gdbm_reorganize_impl((gdbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(_gdbm_gdbm_sync__doc__,
@@ -239,11 +271,18 @@ _gdbm_gdbm_sync_impl(gdbmobject *self, PyTypeObject *cls);
 static PyObject *
 _gdbm_gdbm_sync(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "sync() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _gdbm_gdbm_sync_impl((gdbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _gdbm_gdbm_sync_impl((gdbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(_gdbm_gdbm_clear__doc__,
@@ -261,11 +300,18 @@ _gdbm_gdbm_clear_impl(gdbmobject *self, PyTypeObject *cls);
 static PyObject *
 _gdbm_gdbm_clear(PyObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
+    PyObject *return_value = NULL;
+
     if (nargs || (kwnames && PyTuple_GET_SIZE(kwnames))) {
         PyErr_SetString(PyExc_TypeError, "clear() takes no arguments");
-        return NULL;
+        goto exit;
     }
-    return _gdbm_gdbm_clear_impl((gdbmobject *)self, cls);
+    Py_BEGIN_CRITICAL_SECTION(self);
+    return_value = _gdbm_gdbm_clear_impl((gdbmobject *)self, cls);
+    Py_END_CRITICAL_SECTION();
+
+exit:
+    return return_value;
 }
 
 PyDoc_STRVAR(dbmopen__doc__,
@@ -343,4 +389,4 @@ dbmopen(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=d974cb39e4ee5d67 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=8bca34ce9d4493dd input=a9049054013a1b77]*/
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index b7300def8dc75f..165e3c5abd95b8 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -9538,6 +9538,18 @@ os_getlogin_impl(PyObject *module)
     }
     else
         result = PyErr_SetFromWindowsErr(GetLastError());
+#elif defined (HAVE_GETLOGIN_R)
+    /* AFAIK the maximum length should be 32, but this is not checkable */
+    char name[64];
+    int err = getlogin_r(name, sizeof(name));
+    if (err) {
+        int old_errno = errno;
+        errno = -err;
+        posix_error();
+        errno = old_errno;
+    } else {
+        result = PyUnicode_DecodeFSDefault(name);
+    }
 #else
     char *name;
     int old_errno = errno;
diff --git a/Modules/pwdmodule.c b/Modules/pwdmodule.c
index 2240e2078b2d98..dfcd9eb2d863ac 100644
--- a/Modules/pwdmodule.c
+++ b/Modules/pwdmodule.c
@@ -301,18 +301,28 @@ pwd_getpwall_impl(PyObject *module)
     struct passwd *p;
     if ((d = PyList_New(0)) == NULL)
         return NULL;
+
+#ifdef Py_GIL_DISABLED
+    static PyMutex getpwall_mutex = {0};
+    PyMutex_Lock(&getpwall_mutex);
+#endif
     setpwent();
+
     while ((p = getpwent()) != NULL) {
         PyObject *v = mkpwent(module, p);
         if (v == NULL || PyList_Append(d, v) != 0) {
             Py_XDECREF(v);
-            Py_DECREF(d);
-            endpwent();
-            return NULL;
+            Py_CLEAR(d);
+            goto done;
         }
         Py_DECREF(v);
     }
+
+done:
     endpwent();
+#ifdef Py_GIL_DISABLED
+    PyMutex_Unlock(&getpwall_mutex);
+#endif
     return d;
 }
 #endif
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 76e16bc3a2d3ec..2305a18dc81776 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -6269,7 +6269,7 @@ Return the true host name, a list of aliases, and a list of IP addresses,\n\
 for a host.  The host argument is a string giving a host name or IP number.");
 #endif
 
-#ifdef HAVE_GETSERVBYNAME
+#if defined(HAVE_GETSERVBYNAME_R) || defined (HAVE_GETSERVBYNAME)
 /* Python interface to getservbyname(name).
    This only returns the port number, since the other info is already
    known or not useful (like the list of aliases). */
@@ -6279,6 +6279,12 @@ static PyObject *
 socket_getservbyname(PyObject *self, PyObject *args)
 {
     const char *name, *proto=NULL;
+#ifdef HAVE_GETSERVBYNAME_R
+    struct servent entry;
+    /* TODO: The man page says 1024 is usually enough, start with that and
+       retry if insufficient? */
+    char buf[16384];
+#endif
     struct servent *sp;
     if (!PyArg_ParseTuple(args, "s|s:getservbyname", &name, &proto))
         return NULL;
@@ -6288,7 +6294,11 @@ socket_getservbyname(PyObject *self, PyObject *args)
     }
 
     Py_BEGIN_ALLOW_THREADS
+#ifdef HAVE_GETSERVBYNAME_R
+    getservbyname_r(name, proto, &entry, buf, sizeof(buf), &sp);
+#else
     sp = getservbyname(name, proto);
+#endif
     Py_END_ALLOW_THREADS
     if (sp == NULL) {
         PyErr_SetString(PyExc_OSError, "service/proto not found");
@@ -6305,7 +6315,7 @@ The optional protocol name, if given, should be 'tcp' or 'udp',\n\
 otherwise any protocol will match.");
 #endif
 
-#ifdef HAVE_GETSERVBYPORT
+#if defined(HAVE_GETSERVBYPORT_R) || defined (HAVE_GETSERVBYPORT)
 /* Python interface to getservbyport(port).
    This only returns the service name, since the other info is already
    known or not useful (like the list of aliases). */
@@ -6316,6 +6326,12 @@ socket_getservbyport(PyObject *self, PyObject *args)
 {
     int port;
     const char *proto=NULL;
+#ifdef HAVE_GETSERVBYPORT_R
+    struct servent entry;
+    /* TODO: The man page says 1024 is usually enough, start with that and
+       retry if insufficient? */
+    char buf[16384];
+#endif
     struct servent *sp;
     if (!PyArg_ParseTuple(args, "i|s:getservbyport", &port, &proto))
         return NULL;
@@ -6331,7 +6347,11 @@ socket_getservbyport(PyObject *self, PyObject *args)
     }
 
     Py_BEGIN_ALLOW_THREADS
+#ifdef HAVE_GETSERVBYPORT_R
+    getservbyport_r(htons((short)port), proto, &entry, buf, sizeof(buf), &sp);
+#else
     sp = getservbyport(htons((short)port), proto);
+#endif
     Py_END_ALLOW_THREADS
     if (sp == NULL) {
         PyErr_SetString(PyExc_OSError, "port/proto not found");
@@ -6348,7 +6368,7 @@ The optional protocol name, if given, should be 'tcp' or 'udp',\n\
 otherwise any protocol will match.");
 #endif
 
-#ifdef HAVE_GETPROTOBYNAME
+#if defined(HAVE_GETPROTOBYNAME_R) || defined (HAVE_GETPROTOBYNAME)
 /* Python interface to getprotobyname(name).
    This only returns the protocol number, since the other info is
    already known or not useful (like the list of aliases). */
@@ -6358,11 +6378,21 @@ static PyObject *
 socket_getprotobyname(PyObject *self, PyObject *args)
 {
     const char *name;
+#ifdef HAVE_GETPROTOBYNAME_R
+    struct protoent entry;
+    /* TODO: The man page says 1024 is usually enough, start with that and
+       retry if insufficient? */
+    char buf[16384];
+#endif
     struct protoent *sp;
     if (!PyArg_ParseTuple(args, "s:getprotobyname", &name))
         return NULL;
     Py_BEGIN_ALLOW_THREADS
+#ifdef HAVE_GETPROTOBYNAME_R
+    getprotobyname_r(name, &entry, buf, sizeof(buf), &sp);
+#else
     sp = getprotobyname(name);
+#endif
     Py_END_ALLOW_THREADS
     if (sp == NULL) {
         PyErr_SetString(PyExc_OSError, "protocol not found");
@@ -7415,15 +7445,15 @@ static PyMethodDef socket_methods[] = {
     {"sethostname",             socket_sethostname,
      METH_VARARGS,  sethostname_doc},
 #endif
-#ifdef HAVE_GETSERVBYNAME
+#if defined(HAVE_GETSERVBYNAME_R) || defined (HAVE_GETSERVBYNAME)
     {"getservbyname",           socket_getservbyname,
      METH_VARARGS, getservbyname_doc},
 #endif
-#ifdef HAVE_GETSERVBYPORT
+#if defined(HAVE_GETSERVBYPORT_R) || defined (HAVE_GETSERVBYPORT)
     {"getservbyport",           socket_getservbyport,
      METH_VARARGS, getservbyport_doc},
 #endif
-#ifdef HAVE_GETPROTOBYNAME
+#if defined (HAVE_GETPROTOBYNAME_R) || defined (HAVE_GETPROTOBYNAME)
     {"getprotobyname",          socket_getprotobyname,
      METH_VARARGS, getprotobyname_doc},
 #endif
diff --git a/configure b/configure
index decb8f2449d162..8261fe1fb8fdc4 100755
--- a/configure
+++ b/configure
@@ -19240,6 +19240,12 @@ if test "x$ac_cv_func_getlogin" = xyes
 then :
   printf "%s\n" "#define HAVE_GETLOGIN 1" >>confdefs.h
 
+fi
+ac_fn_c_check_func "$LINENO" "getlogin_r" "ac_cv_func_getlogin_r"
+if test "x$ac_cv_func_getlogin_r" = xyes
+then :
+  printf "%s\n" "#define HAVE_GETLOGIN_R 1" >>confdefs.h
+
 fi
 ac_fn_c_check_func "$LINENO" "getpeername" "ac_cv_func_getpeername"
 if test "x$ac_cv_func_getpeername" = xyes
@@ -22615,6 +22621,129 @@ fi
 
 
 
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for getservbyname_r" >&5
+printf %s "checking for getservbyname_r... " >&6; }
+if test ${ac_cv_func_getservbyname_r+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <netdb.h>
+int
+main (void)
+{
+void *x=getservbyname_r
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_func_getservbyname_r=yes
+else case e in #(
+  e) ac_cv_func_getservbyname_r=no ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+   ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_getservbyname_r" >&5
+printf "%s\n" "$ac_cv_func_getservbyname_r" >&6; }
+  if test "x$ac_cv_func_getservbyname_r" = xyes
+then :
+
+printf "%s\n" "#define HAVE_GETSERVBYNAME_R 1" >>confdefs.h
+
+fi
+
+
+
+
+
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for getservbyport_r" >&5
+printf %s "checking for getservbyport_r... " >&6; }
+if test ${ac_cv_func_getservbyport_r+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <netdb.h>
+int
+main (void)
+{
+void *x=getservbyport_r
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_func_getservbyport_r=yes
+else case e in #(
+  e) ac_cv_func_getservbyport_r=no ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+   ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_getservbyport_r" >&5
+printf "%s\n" "$ac_cv_func_getservbyport_r" >&6; }
+  if test "x$ac_cv_func_getservbyport_r" = xyes
+then :
+
+printf "%s\n" "#define HAVE_GETSERVBYPORT_R 1" >>confdefs.h
+
+fi
+
+
+
+
+
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for getprotobyname_r" >&5
+printf %s "checking for getprotobyname_r... " >&6; }
+if test ${ac_cv_func_getprotobyname_r+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <netdb.h>
+int
+main (void)
+{
+void *x=getprotobyname_r
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_func_getprotobyname_r=yes
+else case e in #(
+  e) ac_cv_func_getprotobyname_r=no ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+   ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_getprotobyname_r" >&5
+printf "%s\n" "$ac_cv_func_getprotobyname_r" >&6; }
+  if test "x$ac_cv_func_getprotobyname_r" = xyes
+then :
+
+printf "%s\n" "#define HAVE_GETPROTOBYNAME_R 1" >>confdefs.h
+
+fi
+
+
+
+
+
 
 
 
diff --git a/configure.ac b/configure.ac
index 004797b5233c20..d6dccdb31d5596 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5137,7 +5137,7 @@ AC_CHECK_FUNCS([ \
   faccessat fchmod fchmodat fchown fchownat fdopendir fdwalk fexecve \
   fork fork1 fpathconf fstatat ftime ftruncate futimens futimes futimesat \
   gai_strerror getegid geteuid getgid getgrent getgrgid getgrgid_r \
-  getgrnam_r getgrouplist gethostname getitimer getloadavg getlogin \
+  getgrnam_r getgrouplist gethostname getitimer getloadavg getlogin getlogin_r \
   getpeername getpgid getpid getppid getpriority _getpty \
   getpwent getpwnam_r getpwuid getpwuid_r getresgid getresuid getrusage getsid getspent \
   getspnam getuid getwd grantpt if_nameindex initgroups kill killpg lchown linkat \
@@ -5395,6 +5395,9 @@ PY_CHECK_NETDB_FUNC([getservbyport])
 PY_CHECK_NETDB_FUNC([gethostbyname])
 PY_CHECK_NETDB_FUNC([gethostbyaddr])
 PY_CHECK_NETDB_FUNC([getprotobyname])
+PY_CHECK_NETDB_FUNC([getservbyname_r])
+PY_CHECK_NETDB_FUNC([getservbyport_r])
+PY_CHECK_NETDB_FUNC([getprotobyname_r])
 
 dnl PY_CHECK_SOCKET_FUNC(FUNCTION)
 AC_DEFUN([PY_CHECK_SOCKET_FUNC], [PY_CHECK_FUNC([$1], [
diff --git a/pyconfig.h.in b/pyconfig.h.in
index aa086d49e90a5b..a60a180d2c53f0 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -530,6 +530,9 @@
 /* Define to 1 if you have the 'getlogin' function. */
 #undef HAVE_GETLOGIN
 
+/* Define to 1 if you have the 'getlogin_r' function. */
+#undef HAVE_GETLOGIN_R
+
 /* Define to 1 if you have the 'getnameinfo' function. */
 #undef HAVE_GETNAMEINFO
 
@@ -557,6 +560,9 @@
 /* Define if you have the 'getprotobyname' function. */
 #undef HAVE_GETPROTOBYNAME
 
+/* Define if you have the 'getprotobyname_r' function. */
+#undef HAVE_GETPROTOBYNAME_R
+
 /* Define to 1 if you have the 'getpwent' function. */
 #undef HAVE_GETPWENT
 
@@ -587,9 +593,15 @@
 /* Define if you have the 'getservbyname' function. */
 #undef HAVE_GETSERVBYNAME
 
+/* Define if you have the 'getservbyname_r' function. */
+#undef HAVE_GETSERVBYNAME_R
+
 /* Define if you have the 'getservbyport' function. */
 #undef HAVE_GETSERVBYPORT
 
+/* Define if you have the 'getservbyport_r' function. */
+#undef HAVE_GETSERVBYPORT_R
+
 /* Define to 1 if you have the 'getsid' function. */
 #undef HAVE_GETSID