39 # include <sys/linux-syscalls.h>
45 /* If this is ever expanded to non-Linux platforms, verify what calls are
57 #  define dirfd(dirp) ((dirp)->dd_fd)
74 #define POSIX_CALL(call)   do { if ((call) == -1) goto error; } while (0)
76 static struct PyModuleDef _posixsubprocessmodule;
78 /* Convert ASCII to a positive int, no libc call. no overflow. -1 on error. */
79 static int
84         num = num * 10 + (*name - '0');  in _pos_int_from_ascii()
88         return -1;  /* Non digit found, not a number. */  in _pos_int_from_ascii()
94 /* When /dev/fd isn't mounted it is often a static directory populated
100 static int
110         return 0;  /* / == /dev == /dev/fd means it is static. #fail */  in _is_fdescfs_mounted_on_dev_fd()
117 static int
121     long prev_fd = -1;  in _sanity_check_python_fd_sequence()
140 static int
146     Py_ssize_t search_max = fd_sequence_len - 1;  in _is_fd_in_sorted_fd_sequence()
157             search_max = middle - 1;  in _is_fd_in_sorted_fd_sequence()
170  * Returns: -1 on error, 0 on success.
172 static int
181         if (fd == -1 && PyErr_Occurred()) {  in convert_fds_to_keep_to_c()
182             return -1;  in convert_fds_to_keep_to_c()
187             return -1;  in convert_fds_to_keep_to_c()
195 /* This function must be async-signal-safe as it is called from child_exec()
198 static int
212             return -1;  in make_inheritable()
221 static long
233      * safe.  TODO - Someone should audit OpenBSD to make sure. */  in safe_get_max_fd()
239     if (local_max_fd == -1)  in safe_get_max_fd()
249  * If end_fd == -1, it's guessed via safe_get_max_fd(), but it isn't
254 static int
261     if (end_fd == -1) {  in _close_range_except()
271         if (closer(start_fd, keep_fd - 1) != 0)  in _close_range_except()
272             return -1;  in _close_range_except()
277             return -1;  in _close_range_except()
294    char           d_name[256];  /* Filename (null-terminated) */
297 static int
322 static void
328     if (fd_dir_fd == -1) {  in _close_open_fds_safe()
330         _close_range_except(start_fd, -1,  in _close_open_fds_safe()
345             for (offset = 0; offset < bytes; offset += entry->d_reclen) {  in _close_open_fds_safe()
348                 if ((fd = _pos_int_from_ascii(entry->d_name)) < 0)  in _close_open_fds_safe()
365 static int
383  *   http://womble.decadent.org.uk/readdir_r-advisory.html
385 static void
411         _close_range_except(start_fd, -1, fds_to_keep, fds_to_keep_len,  in _close_open_fds_maybe_unsafe()
418         int fd_used_by_opendir = start_fd - 1;  in _close_open_fds_maybe_unsafe()
423             if ((fd = _pos_int_from_ascii(dir_entry->d_name)) < 0)  in _close_open_fds_maybe_unsafe()
434             _close_range_except(start_fd, -1, fds_to_keep, fds_to_keep_len,  in _close_open_fds_maybe_unsafe()
446  * async-signal-safe.
455 static int
462 static void
480 static void
500         if (sigaction(sig, NULL, &sa) == -1) {  in reset_signal_handlers()
523  * All of the code in this function must only use async-signal-safe functions,
533  * async-signal-safe functions vfork-unsafe. In particular, on Linux,
535  * they have to interact with the library-level thread list and send
536  * library-internal signals to implement per-process credentials semantics
540  * See bpo-35823 for further discussion and references.
543  * behavior since resource limits were per-thread attributes before
547  * If vfork-unsafe functionality is desired after vfork(), consider using
550 Py_NO_INLINE static void
579     if (p2cwrite != -1)  in child_exec()
581     if (c2pread != -1)  in child_exec()
583     if (errread != -1)  in child_exec()
606        would be a no-op (issue #10806). */  in child_exec()
611     else if (p2cread != -1)  in child_exec()
618     else if (c2pwrite != -1)  in child_exec()
625     else if (errwrite != -1)  in child_exec()
629      * _close_open_fds takes care when it is not already non-inheritable. */  in child_exec()
677         /* This is where the user has asked us to deadlock their program. */  in child_exec()
689         /* Py_DECREF(result); - We're about to exec so why bother? */  in child_exec()
694         /* TODO HP-UX could use pstat_getproc() if anyone cares about it. */  in child_exec()
728             *--cur = Py_hexdigits[saved_errno % 16];  in child_exec()
731         _Py_write_noraise(errpipe_write, cur, hex_errno + sizeof(hex_errno) - cur);  in child_exec()
751  * child_exec() should not be inlined to avoid spurious -Wclobber warnings from
752  * GCC (see bpo-35823).
754 Py_NO_INLINE static pid_t
785         if (pid == -1) {  in do_fork_exec()
787              * allowed in a process by the kernel, vfork can return -1  in do_fork_exec()
808          * This call may not be async-signal-safe but neither is calling  in do_fork_exec()
809          * back into Python.  The user asked us to use hope as a strategy  in do_fork_exec()
827 static PyObject *
840     pid_t pgid_to_set = -1;  in subprocess_fork_exec()
847     pid_t pid = -1;  in subprocess_fork_exec()
886     if (config->_isolated_interpreter) {  in subprocess_fork_exec()
1049     /* NOTE: When old_sigmask is non-NULL, do_fork_exec() may use vfork(). */  in subprocess_fork_exec()
1062          * might send such a signal to be vfork-unsafe and do not call it in  in subprocess_fork_exec()
1084     if (pid == -1) {  in subprocess_fork_exec()
1095          * such as QEMU user-mode emulation, the parent won't be blocked,  in subprocess_fork_exec()
1139     return pid == -1 ? NULL : PyLong_FromPid(pid);  in subprocess_fork_exec()
1176 static PyMethodDef module_methods[] = {
1181 static PyModuleDef_Slot _posixsubprocess_slots[] = {
1185 static struct PyModuleDef _posixsubprocessmodule = {