[Python-checkins] bpo-20104: Fix leaks and errors in new os.posix_spawn (GH-5418)

Mon Jan 29 15:34:48 EST 2018

https://github.com/python/cpython/commit/0cd6bca65519109a8a7862d38ba1b8924e432a16
commit: 0cd6bca65519109a8a7862d38ba1b8924e432a16
branch: master
author: Pablo Galindo <Pablogsal at gmail.com>
committer: Gregory P. Smith <greg at krypto.org>
date: 2018年01月29日T12:34:42-08:00
summary:
bpo-20104: Fix leaks and errors in new os.posix_spawn (GH-5418)
* Fix memory leaks and error handling in posix spawn
* Improve error handling when destroying the file_actions object
* Py_DECREF the result of PySequence_Fast on error
* Handle uninitialized pid
* Use OSError if file actions fails to initialize
* Move _file_actions to outer scope to avoid undefined behaviour
* Remove HAVE_POSIX_SPAWN define in Modules/posixmodule.c
* Unshadow exception and clean error message
files:
M Modules/posixmodule.c

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 8b11e981f115..46f3adaf4dc3 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -176,14 +176,6 @@ corresponding Unix manual entries for more information on calls.");
 #else
 /* Unix functions that the configure script doesn't check for */
 #define HAVE_EXECV 1
-/* bpo-32705: Current Android does not have posix_spawn
- * Most likely posix_spawn will be available in next Android version (Android
- * P, API 28). Need revisit then. See
- * https://android-review.googlesource.com/c/platform/bionic/+/504842
- **/
-#ifndef __ANDROID__
-#define HAVE_POSIX_SPAWN 1
-#endif
 #define HAVE_FORK 1
 #if defined(__USLC__) && defined(__SCO_VERSION__) /* SCO UDK Compiler */
 #define HAVE_FORK1 1
@@ -5139,17 +5131,22 @@ os_posix_spawn_impl(PyObject *module, path_t *path, PyObject *argv,
 /*[clinic end generated code: output=d023521f541c709c input=0ec9f1cfdc890be5]*/
 {
 EXECV_CHAR **argvlist = NULL;
- EXECV_CHAR **envlist;
+ EXECV_CHAR **envlist = NULL;
+ posix_spawn_file_actions_t _file_actions;
+ posix_spawn_file_actions_t *file_actionsp = NULL;
 Py_ssize_t argc, envc;
+ PyObject* result = NULL;
+ PyObject* seq = NULL;
+ 
 
 /* posix_spawn has three arguments: (path, argv, env), where
 argv is a list or tuple of strings and env is a dictionary
 like posix.environ. */
 
- if (!PySequence_Check(argv)){
+ if (!PySequence_Check(argv)) {
 PyErr_SetString(PyExc_TypeError,
 "posix_spawn: argv must be a tuple or list");
- goto fail;
+ goto exit;
 }
 argc = PySequence_Size(argv);
 if (argc < 1) {
@@ -5160,40 +5157,37 @@ os_posix_spawn_impl(PyObject *module, path_t *path, PyObject *argv,
 if (!PyMapping_Check(env)) {
 PyErr_SetString(PyExc_TypeError,
 "posix_spawn: environment must be a mapping object");
- goto fail;
+ goto exit;
 }
 
 argvlist = parse_arglist(argv, &argc);
 if (argvlist == NULL) {
- goto fail;
+ goto exit;
 }
 if (!argvlist[0][0]) {
 PyErr_SetString(PyExc_ValueError,
 "posix_spawn: argv first element cannot be empty");
- goto fail;
+ goto exit;
 }
 
 envlist = parse_envlist(env, &envc);
- if (envlist == NULL)
- goto fail;
+ if (envlist == NULL) {
+ goto exit;
+ }
 
 pid_t pid;
- posix_spawn_file_actions_t *file_actionsp = NULL;
- if (file_actions != NULL && file_actions != Py_None){
- posix_spawn_file_actions_t _file_actions;
+ if (file_actions != NULL && file_actions != Py_None) {
 if(posix_spawn_file_actions_init(&_file_actions) != 0){
- PyErr_SetString(PyExc_TypeError,
+ PyErr_SetString(PyExc_OSError,
 "Error initializing file actions");
- goto fail;
+ goto exit;
 }
 
-
 file_actionsp = &_file_actions;
 
-
- PyObject* seq = PySequence_Fast(file_actions, "file_actions must be a sequence");
- if(seq == NULL){
- goto fail;
+ seq = PySequence_Fast(file_actions, "file_actions must be a sequence");
+ if(seq == NULL) {
+ goto exit;
 }
 PyObject* file_actions_obj;
 PyObject* mode_obj;
@@ -5201,9 +5195,9 @@ os_posix_spawn_impl(PyObject *module, path_t *path, PyObject *argv,
 for (int i = 0; i < PySequence_Fast_GET_SIZE(seq); ++i) {
 file_actions_obj = PySequence_Fast_GET_ITEM(seq, i);
 
- if(!PySequence_Check(file_actions_obj) | !PySequence_Size(file_actions_obj)){
+ if(!PySequence_Check(file_actions_obj) | !PySequence_Size(file_actions_obj)) {
 PyErr_SetString(PyExc_TypeError,"Each file_action element must be a non empty sequence");
- goto fail;
+ goto exit;
 }
 
 
@@ -5215,83 +5209,103 @@ os_posix_spawn_impl(PyObject *module, path_t *path, PyObject *argv,
 switch(mode) {
 
 case POSIX_SPAWN_OPEN:
- if(PySequence_Size(file_actions_obj) != 5){
+ if(PySequence_Size(file_actions_obj) != 5) {
 PyErr_SetString(PyExc_TypeError,"A open file_action object must have 5 elements");
- goto fail;
+ goto exit;
 }
 
 long open_fd = PyLong_AsLong(PySequence_GetItem(file_actions_obj, 1));
 if(PyErr_Occurred()) {
- goto fail;
+ goto exit;
 }
 const char* open_path = PyUnicode_AsUTF8(PySequence_GetItem(file_actions_obj, 2));
- if(open_path == NULL){
- goto fail;
+ if(open_path == NULL) {
+ goto exit;
 }
 long open_oflag = PyLong_AsLong(PySequence_GetItem(file_actions_obj, 3));
 if(PyErr_Occurred()) {
- goto fail;
+ goto exit;
 }
 long open_mode = PyLong_AsLong(PySequence_GetItem(file_actions_obj, 4));
 if(PyErr_Occurred()) {
- goto fail;
+ goto exit;
+ }
+ if(posix_spawn_file_actions_addopen(file_actionsp, open_fd, open_path, open_oflag, open_mode)) {
+ PyErr_SetString(PyExc_OSError,"Failed to add open file action");
+ goto exit;
 }
- posix_spawn_file_actions_addopen(file_actionsp, open_fd, open_path, open_oflag, open_mode);
+ 
 break;
 
 case POSIX_SPAWN_CLOSE:
 if(PySequence_Size(file_actions_obj) != 2){
 PyErr_SetString(PyExc_TypeError,"A close file_action object must have 2 elements");
- goto fail;
+ goto exit;
 }
 
 long close_fd = PyLong_AsLong(PySequence_GetItem(file_actions_obj, 1));
 if(PyErr_Occurred()) {
- goto fail;
+ goto exit;
+ }
+ if(posix_spawn_file_actions_addclose(file_actionsp, close_fd)) {
+ PyErr_SetString(PyExc_OSError,"Failed to add close file action");
+ goto exit;
 }
- posix_spawn_file_actions_addclose(file_actionsp, close_fd);
 break;
 
 case POSIX_SPAWN_DUP2:
 if(PySequence_Size(file_actions_obj) != 3){
 PyErr_SetString(PyExc_TypeError,"A dup2 file_action object must have 3 elements");
- goto fail;
+ goto exit;
 }
 
 long fd1 = PyLong_AsLong(PySequence_GetItem(file_actions_obj, 1));
 if(PyErr_Occurred()) {
- goto fail;
+ goto exit;
 }
 long fd2 = PyLong_AsLong(PySequence_GetItem(file_actions_obj, 2));
 if(PyErr_Occurred()) {
- goto fail;
+ goto exit;
+ }
+ if(posix_spawn_file_actions_adddup2(file_actionsp, fd1, fd2)) {
+ PyErr_SetString(PyExc_OSError,"Failed to add dup2 file action");
+ goto exit;
 }
- posix_spawn_file_actions_adddup2(file_actionsp, fd1, fd2);
 break;
 
 default:
 PyErr_SetString(PyExc_TypeError,"Unknown file_actions identifier");
- goto fail;
+ goto exit;
 }
 }
- Py_DECREF(seq);
-}
+ }
 
 _Py_BEGIN_SUPPRESS_IPH
- posix_spawn(&pid, path->narrow, file_actionsp, NULL, argvlist, envlist);
- return PyLong_FromPid(pid);
+ int err_code = posix_spawn(&pid, path->narrow, file_actionsp, NULL, argvlist, envlist);
 _Py_END_SUPPRESS_IPH
+ if(err_code) {
+ PyErr_SetString(PyExc_OSError,"posix_spawn call failed");
+ goto exit;
+ }
+ result = PyLong_FromPid(pid);
 
- path_error(path);
+exit:
 
- free_string_array(envlist, envc);
+ Py_XDECREF(seq);
 
-fail:
+ if(file_actionsp) {
+ posix_spawn_file_actions_destroy(file_actionsp);
+ }
+ 
+ if (envlist) {
+ free_string_array(envlist, envc);
+ }
 
 if (argvlist) {
 free_string_array(argvlist, argc);
 }
- return NULL;
+
+ return result;
 
 
 }
