Issue #25764: Preserve subprocess fork exception when preexec_fn used

Also fix handling of failure to release the import lock.
This commit is contained in:
Martin Panter 2015-11-30 02:21:41 +00:00
parent c7217d7c22
commit afdd51343c
3 changed files with 37 additions and 17 deletions

View File

@ -1416,6 +1416,22 @@ class POSIXProcessTestCase(BaseTestCase):
if not enabled:
gc.disable()
def test_preexec_fork_failure(self):
# The internal code did not preserve the previous exception when
# re-enabling garbage collection
try:
from resource import getrlimit, setrlimit, RLIMIT_NPROC
except ImportError as err:
self.skipTest(err) # RLIMIT_NPROC is specific to Linux and BSD
limits = getrlimit(RLIMIT_NPROC)
[_, hard] = limits
setrlimit(RLIMIT_NPROC, (0, hard))
self.addCleanup(setrlimit, RLIMIT_NPROC, limits)
# Forking should raise EAGAIN, translated to BlockingIOError
with self.assertRaises(BlockingIOError):
subprocess.call([sys.executable, '-c', ''],
preexec_fn=lambda: None)
def test_args_string(self):
# args is a string
fd, fname = tempfile.mkstemp()

View File

@ -115,6 +115,9 @@ Core and Builtins
Library
-------
- Issue #25764: In the subprocess module, preserve any exception caused by
fork() failure when preexec_fn is used.
- Issue #6478: _strptime's regexp cache now is reset after changing timezone
with time.tzset().

View File

@ -47,17 +47,25 @@
#define POSIX_CALL(call) do { if ((call) == -1) goto error; } while (0)
/* Given the gc module call gc.enable() and return 0 on success. */
/* If gc was disabled, call gc.enable(). Return 0 on success. */
static int
_enable_gc(PyObject *gc_module)
_enable_gc(int need_to_reenable_gc, PyObject *gc_module)
{
PyObject *result;
_Py_IDENTIFIER(enable);
PyObject *exctype, *val, *tb;
result = _PyObject_CallMethodId(gc_module, &PyId_enable, NULL);
if (result == NULL)
return 1;
Py_DECREF(result);
if (need_to_reenable_gc) {
PyErr_Fetch(&exctype, &val, &tb);
result = _PyObject_CallMethodId(gc_module, &PyId_enable, NULL);
if (exctype != NULL) {
PyErr_Restore(exctype, val, tb);
}
if (result == NULL) {
return 1;
}
Py_DECREF(result);
}
return 0;
}
@ -691,6 +699,7 @@ subprocess_fork_exec(PyObject* self, PyObject *args)
_PyImport_ReleaseLock() < 0 && !PyErr_Occurred()) {
PyErr_SetString(PyExc_RuntimeError,
"not holding the import lock");
pid = -1;
}
import_lock_held = 0;
@ -702,9 +711,8 @@ subprocess_fork_exec(PyObject* self, PyObject *args)
_Py_FreeCharPArray(exec_array);
/* Reenable gc in the parent process (or if fork failed). */
if (need_to_reenable_gc && _enable_gc(gc_module)) {
Py_XDECREF(gc_module);
return NULL;
if (_enable_gc(need_to_reenable_gc, gc_module)) {
pid = -1;
}
Py_XDECREF(preexec_fn_args_tuple);
Py_XDECREF(gc_module);
@ -726,14 +734,7 @@ cleanup:
Py_XDECREF(converted_args);
Py_XDECREF(fast_args);
Py_XDECREF(preexec_fn_args_tuple);
/* Reenable gc if it was disabled. */
if (need_to_reenable_gc) {
PyObject *exctype, *val, *tb;
PyErr_Fetch(&exctype, &val, &tb);
_enable_gc(gc_module);
PyErr_Restore(exctype, val, tb);
}
_enable_gc(need_to_reenable_gc, gc_module);
Py_XDECREF(gc_module);
return NULL;
}