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Fixes Issue #14331: Use significantly less stack space when importing modules by

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allocating path buffers on the heap instead of the stack.
This commit is contained in:
Gregory P. Smith 2012-03-18 16:06:53 -07:00
parent 3187749646
commit c809f98143
2 changed files with 130 additions and 39 deletions
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3
Misc/NEWS
View File

@ -10,6 +10,9 @@ What's New in Python 3.2.4
Core and Builtins
-----------------
- Issue #14331: Use significantly less stack space when importing modules by
allocating path buffers on the heap instead of the stack.
- Issue #14334: Prevent in a segfault in type.__getattribute__ when it was not
passed strings.

166
Python/import.c
View File

@ -1291,7 +1291,7 @@ load_source_module(char *name, char *pathname, FILE *fp)
{
struct stat st;
FILE *fpc;
char buf[MAXPATHLEN+1];
char *buf;
char *cpathname;
PyCodeObject *co;
PyObject *m;
@ -1310,6 +1310,10 @@ load_source_module(char *name, char *pathname, FILE *fp)
*/
st.st_mtime &= 0xFFFFFFFF;
}
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
return PyErr_NoMemory();
}
cpathname = make_compiled_pathname(
pathname, buf, (size_t)MAXPATHLEN + 1, !Py_OptimizeFlag);
if (cpathname != NULL &&
@ -1317,9 +1321,9 @@ load_source_module(char *name, char *pathname, FILE *fp)
co = read_compiled_module(cpathname, fpc);
fclose(fpc);
if (co == NULL)
return NULL;
goto error_exit;
if (update_compiled_module(co, pathname) < 0)
return NULL;
goto error_exit;
if (Py_VerboseFlag)
PySys_WriteStderr("import %s # precompiled from %s\n",
name, cpathname);
@ -1328,7 +1332,7 @@ load_source_module(char *name, char *pathname, FILE *fp)
else {
co = parse_source_module(pathname, fp);
if (co == NULL)
return NULL;
goto error_exit;
if (Py_VerboseFlag)
PySys_WriteStderr("import %s # from %s\n",
name, pathname);
@ -1342,7 +1346,12 @@ load_source_module(char *name, char *pathname, FILE *fp)
name, (PyObject *)co, pathname, cpathname);
Py_DECREF(co);
PyMem_FREE(buf);
return m;
error_exit:
PyMem_FREE(buf);
return NULL;
}
/* Get source file -> unicode or None
@ -1351,7 +1360,7 @@ load_source_module(char *name, char *pathname, FILE *fp)
static PyObject *
get_sourcefile(char *file)
{
char py[MAXPATHLEN + 1];
char *py = NULL;
Py_ssize_t len;
PyObject *u;
struct stat statbuf;
@ -1366,6 +1375,10 @@ get_sourcefile(char *file)
return PyUnicode_DecodeFSDefault(file);
}
py = PyMem_MALLOC(MAXPATHLEN+1);
if (py == NULL) {
return PyErr_NoMemory();
}
/* Start by trying to turn PEP 3147 path into source path. If that
* fails, just chop off the trailing character, i.e. legacy pyc path
* to py.
@ -1382,6 +1395,7 @@ get_sourcefile(char *file)
else {
u = PyUnicode_DecodeFSDefault(file);
}
PyMem_FREE(py);
return u;
}
@ -1401,7 +1415,7 @@ load_package(char *name, char *pathname)
PyObject *file = NULL;
PyObject *path = NULL;
int err;
char buf[MAXPATHLEN+1];
char *buf = NULL;
FILE *fp = NULL;
struct filedescr *fdp;
@ -1423,8 +1437,13 @@ load_package(char *name, char *pathname)
err = PyDict_SetItemString(d, "__path__", path);
if (err != 0)
goto error;
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
PyErr_NoMemory();
goto error;
}
buf[0] = '\0';
fdp = find_module(name, "__init__", path, buf, sizeof(buf), &fp, NULL);
fdp = find_module(name, "__init__", path, buf, MAXPATHLEN+1, &fp, NULL);
if (fdp == NULL) {
if (PyErr_ExceptionMatches(PyExc_ImportError)) {
PyErr_Clear();
@ -1442,6 +1461,8 @@ load_package(char *name, char *pathname)
error:
m = NULL;
cleanup:
if (buf)
PyMem_FREE(buf);
Py_XDECREF(path);
Py_XDECREF(file);
return m;
@ -1571,7 +1592,7 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
static struct filedescr fd_frozen = {"", "", PY_FROZEN};
static struct filedescr fd_builtin = {"", "", C_BUILTIN};
static struct filedescr fd_package = {"", "", PKG_DIRECTORY};
char name[MAXPATHLEN+1];
char *name;
#if defined(PYOS_OS2)
size_t saved_len;
size_t saved_namelen;
@ -1585,6 +1606,11 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
"module name is too long");
return NULL;
}
name = PyMem_MALLOC(MAXPATHLEN+1);
if (name == NULL) {
PyErr_NoMemory();
return NULL;
}
strcpy(name, subname);
/* sys.meta_path import hook */
@ -1596,7 +1622,7 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
PyErr_SetString(PyExc_RuntimeError,
"sys.meta_path must be a list of "
"import hooks");
return NULL;
goto error_exit;
}
Py_INCREF(meta_path); /* zap guard */
npath = PyList_Size(meta_path);
@ -1609,12 +1635,13 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
path : Py_None);
if (loader == NULL) {
Py_DECREF(meta_path);
return NULL; /* true error */
goto error_exit; /* true error */
}
if (loader != Py_None) {
/* a loader was found */
*p_loader = loader;
Py_DECREF(meta_path);
PyMem_FREE(name);
return &importhookdescr;
}
Py_DECREF(loader);
@ -1624,18 +1651,21 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
if (find_frozen(fullname) != NULL) {
strcpy(buf, fullname);
PyMem_FREE(name);
return &fd_frozen;
}
if (path == NULL) {
if (is_builtin(name)) {
strcpy(buf, name);
PyMem_FREE(name);
return &fd_builtin;
}
#ifdef MS_COREDLL
fp = PyWin_FindRegisteredModule(name, &fdp, buf, buflen);
if (fp != NULL) {
*p_fp = fp;
PyMem_FREE(name);
return fdp;
}
#endif
@ -1645,7 +1675,7 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
if (path == NULL || !PyList_Check(path)) {
PyErr_SetString(PyExc_RuntimeError,
"sys.path must be a list of directory names");
return NULL;
goto error_exit;
}
path_hooks = PySys_GetObject("path_hooks");
@ -1653,14 +1683,14 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
PyErr_SetString(PyExc_RuntimeError,
"sys.path_hooks must be a list of "
"import hooks");
return NULL;
goto error_exit;
}
path_importer_cache = PySys_GetObject("path_importer_cache");
if (path_importer_cache == NULL ||
!PyDict_Check(path_importer_cache)) {
PyErr_SetString(PyExc_RuntimeError,
"sys.path_importer_cache must be a dict");
return NULL;
goto error_exit;
}
npath = PyList_Size(path);
@ -1671,11 +1701,11 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
const char *base;
Py_ssize_t size;
if (!v)
return NULL;
goto error_exit;
if (PyUnicode_Check(v)) {
v = PyUnicode_EncodeFSDefault(v);
if (v == NULL)
return NULL;
goto error_exit;
}
else if (!PyBytes_Check(v))
continue;
@ -1703,7 +1733,7 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
importer = get_path_importer(path_importer_cache,
path_hooks, origv);
if (importer == NULL) {
return NULL;
goto error_exit;
}
/* Note: importer is a borrowed reference */
if (importer != Py_None) {
@ -1712,10 +1742,11 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
"find_module",
"s", fullname);
if (loader == NULL)
return NULL; /* error */
goto error_exit; /* error */
if (loader != Py_None) {
/* a loader was found */
*p_loader = loader;
PyMem_FREE(name);
return &importhookdescr;
}
Py_DECREF(loader);
@ -1740,19 +1771,20 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
S_ISDIR(statbuf.st_mode) && /* it's a directory */
case_ok(buf, len, namelen, name)) { /* case matches */
if (find_init_module(buf)) { /* and has __init__.py */
PyMem_FREE(name);
return &fd_package;
}
else {
int err;
PyObject *unicode = PyUnicode_DecodeFSDefault(buf);
if (unicode == NULL)
return NULL;
goto error_exit;
err = PyErr_WarnFormat(PyExc_ImportWarning, 1,
"Not importing directory '%U': missing __init__.py",
unicode);
Py_DECREF(unicode);
if (err)
return NULL;
goto error_exit;
}
}
#endif
@ -1833,10 +1865,15 @@ find_module(char *fullname, char *subname, PyObject *path, char *buf,
if (fp == NULL) {
PyErr_Format(PyExc_ImportError,
"No module named %.200s", name);
return NULL;
goto error_exit;
}
*p_fp = fp;
PyMem_FREE(name);
return fdp;
error_exit:
PyMem_FREE(name);
return NULL;
}
/* case_ok(char* buf, Py_ssize_t len, Py_ssize_t namelen, char* name)
@ -2416,7 +2453,7 @@ static PyObject *
import_module_level(char *name, PyObject *globals, PyObject *locals,
PyObject *fromlist, int level)
{
char buf[MAXPATHLEN+1];
char *buf;
Py_ssize_t buflen = 0;
PyObject *parent, *head, *next, *tail;
@ -2430,14 +2467,18 @@ import_module_level(char *name, PyObject *globals, PyObject *locals,
return NULL;
}
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
return PyErr_NoMemory();
}
parent = get_parent(globals, buf, &buflen, level);
if (parent == NULL)
return NULL;
goto error_exit;
head = load_next(parent, level < 0 ? Py_None : parent, &name, buf,
&buflen);
if (head == NULL)
return NULL;
goto error_exit;
tail = head;
Py_INCREF(tail);
@ -2446,7 +2487,7 @@ import_module_level(char *name, PyObject *globals, PyObject *locals,
Py_DECREF(tail);
if (next == NULL) {
Py_DECREF(head);
return NULL;
goto error_exit;
}
tail = next;
}
@ -2458,7 +2499,7 @@ import_module_level(char *name, PyObject *globals, PyObject *locals,
Py_DECREF(head);
PyErr_SetString(PyExc_ValueError,
"Empty module name");
return NULL;
goto error_exit;
}
if (fromlist != NULL) {
@ -2468,16 +2509,22 @@ import_module_level(char *name, PyObject *globals, PyObject *locals,
if (fromlist == NULL) {
Py_DECREF(tail);
PyMem_FREE(buf);
return head;
}
Py_DECREF(head);
if (!ensure_fromlist(tail, fromlist, buf, buflen, 0)) {
Py_DECREF(tail);
return NULL;
goto error_exit;
}
PyMem_FREE(buf);
return tail;
error_exit:
PyMem_FREE(buf);
return NULL;
}
PyObject *
@ -2880,7 +2927,7 @@ import_submodule(PyObject *mod, char *subname, char *fullname)
}
else {
PyObject *path, *loader = NULL;
char buf[MAXPATHLEN+1];
char *buf;
struct filedescr *fdp;
FILE *fp = NULL;
@ -2895,11 +2942,16 @@ import_submodule(PyObject *mod, char *subname, char *fullname)
}
}
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
return PyErr_NoMemory();
}
buf[0] = '\0';
fdp = find_module(fullname, subname, path, buf, MAXPATHLEN+1,
&fp, &loader);
Py_XDECREF(path);
if (fdp == NULL) {
PyMem_FREE(buf);
if (!PyErr_ExceptionMatches(PyExc_ImportError))
return NULL;
PyErr_Clear();
@ -2914,6 +2966,7 @@ import_submodule(PyObject *mod, char *subname, char *fullname)
Py_XDECREF(m);
m = NULL;
}
PyMem_FREE(buf);
}
return m;
@ -2931,7 +2984,7 @@ PyImport_ReloadModule(PyObject *m)
PyObject *modules = PyImport_GetModuleDict();
PyObject *path = NULL, *loader = NULL, *existing_m = NULL;
char *name, *subname;
char buf[MAXPATHLEN+1];
char *buf;
struct filedescr *fdp;
FILE *fp = NULL;
PyObject *newm;
@ -2991,6 +3044,11 @@ PyImport_ReloadModule(PyObject *m)
if (path == NULL)
PyErr_Clear();
}
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
Py_XDECREF(path);
return PyErr_NoMemory();
}
buf[0] = '\0';
fdp = find_module(name, subname, path, buf, MAXPATHLEN+1, &fp, &loader);
Py_XDECREF(path);
@ -2998,6 +3056,7 @@ PyImport_ReloadModule(PyObject *m)
if (fdp == NULL) {
Py_XDECREF(loader);
imp_modules_reloading_clear();
PyMem_FREE(buf);
return NULL;
}
@ -3015,6 +3074,7 @@ PyImport_ReloadModule(PyObject *m)
PyDict_SetItemString(modules, name, m);
}
imp_modules_reloading_clear();
PyMem_FREE(buf);
return newm;
}
@ -3168,26 +3228,32 @@ call_find_module(char *name, PyObject *path)
PyObject *fob, *ret;
PyObject *pathobj;
struct filedescr *fdp;
char pathname[MAXPATHLEN+1];
char *pathname;
FILE *fp = NULL;
int fd = -1;
char *found_encoding = NULL;
char *encoding = NULL;
pathname = PyMem_MALLOC(MAXPATHLEN+1);
if (pathname == NULL) {
return PyErr_NoMemory();
}
pathname[0] = '\0';
if (path == Py_None)
path = NULL;
fdp = find_module(NULL, name, path, pathname, MAXPATHLEN+1, &fp, NULL);
if (fdp == NULL)
return NULL;
goto error_exit;
if (fp != NULL) {
fd = fileno(fp);
if (fd != -1)
fd = dup(fd);
fclose(fp);
fp = NULL;
if (fd == -1)
return PyErr_SetFromErrno(PyExc_OSError);
if (fd == -1) {
PyErr_SetFromErrno(PyExc_OSError);
goto error_exit;
}
}
if (fd != -1) {
if (strchr(fdp->mode, 'b') == NULL) {
@ -3197,7 +3263,7 @@ call_find_module(char *name, PyObject *path)
lseek(fd, 0, 0); /* Reset position */
if (found_encoding == NULL && PyErr_Occurred()) {
close(fd);
return NULL;
goto error_exit;
}
encoding = (found_encoding != NULL) ? found_encoding :
(char*)PyUnicode_GetDefaultEncoding();
@ -3207,7 +3273,7 @@ call_find_module(char *name, PyObject *path)
if (fob == NULL) {
close(fd);
PyMem_FREE(found_encoding);
return NULL;
goto error_exit;
}
}
else {
@ -3218,8 +3284,12 @@ call_find_module(char *name, PyObject *path)
ret = Py_BuildValue("NN(ssi)",
fob, pathobj, fdp->suffix, fdp->mode, fdp->type);
PyMem_FREE(found_encoding);
PyMem_FREE(pathname);
return ret;
error_exit:
PyMem_FREE(pathname);
return NULL;
}
static PyObject *
@ -3509,7 +3579,7 @@ imp_cache_from_source(PyObject *self, PyObject *args, PyObject *kws)
{
static char *kwlist[] = {"path", "debug_override", NULL};
char buf[MAXPATHLEN+1];
char *buf;
PyObject *pathbytes;
char *cpathname;
PyObject *debug_override = NULL;
@ -3526,6 +3596,10 @@ imp_cache_from_source(PyObject *self, PyObject *args, PyObject *kws)
return NULL;
}
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
return PyErr_NoMemory();
}
cpathname = make_compiled_pathname(
PyBytes_AS_STRING(pathbytes),
buf, MAXPATHLEN+1, debug);
@ -3533,9 +3607,14 @@ imp_cache_from_source(PyObject *self, PyObject *args, PyObject *kws)
if (cpathname == NULL) {
PyErr_Format(PyExc_SystemError, "path buffer too short");
PyMem_FREE(buf);
return NULL;
}
return PyUnicode_DecodeFSDefault(buf);
{
PyObject *ret = PyUnicode_DecodeFSDefault(buf);
PyMem_FREE(buf);
return ret;
}
}
PyDoc_STRVAR(doc_cache_from_source,
@ -3556,7 +3635,7 @@ imp_source_from_cache(PyObject *self, PyObject *args, PyObject *kws)
PyObject *pathname_obj;
char *pathname;
char buf[MAXPATHLEN+1];
char *buf;
if (!PyArg_ParseTupleAndKeywords(
args, kws, "O&", kwlist,
@ -3564,14 +3643,23 @@ imp_source_from_cache(PyObject *self, PyObject *args, PyObject *kws)
return NULL;
pathname = PyBytes_AS_STRING(pathname_obj);
buf = PyMem_MALLOC(MAXPATHLEN+1);
if (buf == NULL) {
return PyErr_NoMemory();
}
if (make_source_pathname(pathname, buf) == NULL) {
PyErr_Format(PyExc_ValueError, "Not a PEP 3147 pyc path: %s",
pathname);
Py_DECREF(pathname_obj);
PyMem_FREE(buf);
return NULL;
}
Py_DECREF(pathname_obj);
return PyUnicode_FromString(buf);
{
PyObject *ret = PyUnicode_FromString(buf);
PyMem_FREE(buf);
return ret;
}
}
PyDoc_STRVAR(doc_source_from_cache,