Issue #23152: Implement _Py_fstat() to support files larger than 2 GB on Windows.

fstat() may fail with EOVERFLOW on files larger than 2 GB because the file size type is an signed 32-bit integer.

1 files changed, 24 insertions, 22 deletions

diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 9c67394..ff88e40 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -180,9 +180,9 @@ fileio_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 static int
 check_fd(int fd)
 {
-#if defined(HAVE_FSTAT)
-    struct stat buf;
-    if (!_PyVerify_fd(fd) || (fstat(fd, &buf) < 0 && errno == EBADF)) {
+#if defined(HAVE_FSTAT) || defined(MS_WINDOWS)
+    struct _Py_stat_struct buf;
+    if (!_PyVerify_fd(fd) || (_Py_fstat(fd, &buf) < 0 && errno == EBADF)) {
         PyObject *exc;
         char *msg = strerror(EBADF);
         exc = PyObject_CallFunction(PyExc_OSError, "(is)",
@@ -222,8 +222,8 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
 #elif !defined(MS_WINDOWS)
     int *atomic_flag_works = NULL;
 #endif
-#ifdef HAVE_FSTAT
-    struct stat fdfstat;
+#if defined(HAVE_FSTAT) || defined(MS_WINDOWS)
+    struct _Py_stat_struct fdfstat;
 #endif
     int async_err = 0;
 
@@ -420,9 +420,11 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
     }
 
     self->blksize = DEFAULT_BUFFER_SIZE;
-#ifdef HAVE_FSTAT
-    if (fstat(self->fd, &fdfstat) < 0)
+#if defined(HAVE_FSTAT) || defined(MS_WINDOWS)
+    if (_Py_fstat(self->fd, &fdfstat) < 0) {
+        PyErr_SetFromErrno(PyExc_OSError);
         goto error;
+    }
 #if defined(S_ISDIR) && defined(EISDIR)
     /* On Unix, open will succeed for directories.
        In Python, there should be no file objects referring to
@@ -437,7 +439,7 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
     if (fdfstat.st_blksize > 1)
         self->blksize = fdfstat.st_blksize;
 #endif /* HAVE_STRUCT_STAT_ST_BLKSIZE */
-#endif /* HAVE_FSTAT */
+#endif /* HAVE_FSTAT || MS_WINDOWS */
 
 #if defined(MS_WINDOWS) || defined(__CYGWIN__)
     /* don't translate newlines (\r\n <=> \n) */
@@ -603,17 +605,7 @@ fileio_readinto(fileio *self, PyObject *args)
     return PyLong_FromSsize_t(n);
 }
 
-#ifndef HAVE_FSTAT
-
-static PyObject *
-fileio_readall(fileio *self)
-{
-    _Py_IDENTIFIER(readall);
-    return _PyObject_CallMethodId((PyObject*)&PyRawIOBase_Type,
-                                  &PyId_readall, "O", self);
-}
-
-#else
+#if defined(HAVE_FSTAT) || defined(MS_WINDOWS)
 
 static size_t
 new_buffersize(fileio *self, size_t currentsize)
@@ -637,7 +629,7 @@ new_buffersize(fileio *self, size_t currentsize)
 static PyObject *
 fileio_readall(fileio *self)
 {
-    struct stat st;
+    struct _Py_stat_struct st;
     Py_off_t pos, end;
     PyObject *result;
     Py_ssize_t bytes_read = 0;
@@ -655,7 +647,7 @@ fileio_readall(fileio *self)
 #else
     pos = lseek(self->fd, 0L, SEEK_CUR);
 #endif
-    if (fstat(self->fd, &st) == 0)
+    if (_Py_fstat(self->fd, &st) == 0)
         end = st.st_size;
     else
         end = (Py_off_t)-1;
@@ -729,7 +721,17 @@ fileio_readall(fileio *self)
     return result;
 }
 
-#endif /* HAVE_FSTAT */
+#else
+
+static PyObject *
+fileio_readall(fileio *self)
+{
+    _Py_IDENTIFIER(readall);
+    return _PyObject_CallMethodId((PyObject*)&PyRawIOBase_Type,
+                                  &PyId_readall, "O", self);
+}
+
+#endif /* HAVE_FSTAT || MS_WINDOWS */
 
 static PyObject *
 fileio_read(fileio *self, PyObject *args)