issue6559: Adds a pass_fds parameter to subprocess.Popen that allows the caller
to list exactly which file descriptors should be kept open.
diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 15c3dc4..36da2e5 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -42,7 +42,8 @@
int errread, int errwrite,
int errpipe_read, int errpipe_write,
int close_fds, int restore_signals,
- int call_setsid,
+ int call_setsid, Py_ssize_t num_fds_to_keep,
+ PyObject *py_fds_to_keep,
PyObject *preexec_fn,
PyObject *preexec_fn_args_tuple)
{
@@ -91,11 +92,28 @@
/* close() is intentionally not checked for errors here as we are closing */
/* a large range of fds, some of which may be invalid. */
if (close_fds) {
- for (fd_num = 3; fd_num < errpipe_write; ++fd_num) {
- close(fd_num);
+ Py_ssize_t keep_seq_idx;
+ int start_fd = 3;
+ for (keep_seq_idx = 0; keep_seq_idx < num_fds_to_keep; ++keep_seq_idx) {
+ PyObject* py_keep_fd = PySequence_Fast_GET_ITEM(py_fds_to_keep,
+ keep_seq_idx);
+ int keep_fd = PyLong_AsLong(py_keep_fd);
+ if (keep_fd < 0) { /* Negative number, overflow or not a Long. */
+ err_msg = "bad value in fds_to_keep.";
+ errno = 0; /* We don't want to report an OSError. */
+ goto error;
+ }
+ if (keep_fd <= start_fd)
+ continue;
+ for (fd_num = start_fd; fd_num < keep_fd; ++fd_num) {
+ close(fd_num);
+ }
+ start_fd = keep_fd + 1;
}
- for (fd_num = errpipe_write+1; fd_num < max_fd; ++fd_num) {
- close(fd_num);
+ if (start_fd <= max_fd) {
+ for (fd_num = start_fd; fd_num < max_fd; ++fd_num) {
+ close(fd_num);
+ }
}
}
@@ -170,7 +188,7 @@
subprocess_fork_exec(PyObject* self, PyObject *args)
{
PyObject *gc_module = NULL;
- PyObject *executable_list, *py_close_fds;
+ PyObject *executable_list, *py_close_fds, *py_fds_to_keep;
PyObject *env_list, *preexec_fn;
PyObject *process_args, *converted_args = NULL, *fast_args = NULL;
PyObject *preexec_fn_args_tuple = NULL;
@@ -182,11 +200,11 @@
pid_t pid;
int need_to_reenable_gc = 0;
char *const *exec_array, *const *argv = NULL, *const *envp = NULL;
- Py_ssize_t arg_num;
+ Py_ssize_t arg_num, num_fds_to_keep;
if (!PyArg_ParseTuple(
- args, "OOOOOiiiiiiiiiiO:fork_exec",
- &process_args, &executable_list, &py_close_fds,
+ args, "OOOOOOiiiiiiiiiiO:fork_exec",
+ &process_args, &executable_list, &py_close_fds, &py_fds_to_keep,
&cwd_obj, &env_list,
&p2cread, &p2cwrite, &c2pread, &c2pwrite,
&errread, &errwrite, &errpipe_read, &errpipe_write,
@@ -198,6 +216,11 @@
PyErr_SetString(PyExc_ValueError, "errpipe_write must be >= 3");
return NULL;
}
+ num_fds_to_keep = PySequence_Length(py_fds_to_keep);
+ if (num_fds_to_keep < 0) {
+ PyErr_SetString(PyExc_ValueError, "bad fds_to_keep");
+ return NULL;
+ }
/* We need to call gc.disable() when we'll be calling preexec_fn */
if (preexec_fn != Py_None) {
@@ -298,6 +321,7 @@
p2cread, p2cwrite, c2pread, c2pwrite,
errread, errwrite, errpipe_read, errpipe_write,
close_fds, restore_signals, call_setsid,
+ num_fds_to_keep, py_fds_to_keep,
preexec_fn, preexec_fn_args_tuple);
_exit(255);
return NULL; /* Dead code to avoid a potential compiler warning. */