Issue #23752: _Py_fstat() is now responsible to raise the Python exception

Add _Py_fstat_noraise() function when a Python exception is not welcome.

5 files changed, 56 insertions, 23 deletions

diff --git a/Python/dynload_shlib.c b/Python/dynload_shlib.c
index 659adac..1a467fd 100644
--- a/Python/dynload_shlib.c
+++ b/Python/dynload_shlib.c
@@ -71,22 +71,20 @@ dl_funcptr _PyImport_GetDynLoadFunc(const char *shortname,
 
     if (fp != NULL) {
         int i;
-        struct _Py_stat_struct statb;
-        if (_Py_fstat(fileno(fp), &statb) == -1) {
-            PyErr_SetFromErrno(PyExc_IOError);
+        struct _Py_stat_struct status;
+        if (_Py_fstat(fileno(fp), &status) == -1)
             return NULL;
-        }
         for (i = 0; i < nhandles; i++) {
-            if (statb.st_dev == handles[i].dev &&
-                statb.st_ino == handles[i].ino) {
+            if (status.st_dev == handles[i].dev &&
+                status.st_ino == handles[i].ino) {
                 p = (dl_funcptr) dlsym(handles[i].handle,
                                        funcname);
                 return p;
             }
         }
         if (nhandles < 128) {
-            handles[nhandles].dev = statb.st_dev;
-            handles[nhandles].ino = statb.st_ino;
+            handles[nhandles].dev = status.st_dev;
+            handles[nhandles].ino = status.st_ino;
         }
     }
 
diff --git a/Python/fileutils.c b/Python/fileutils.c
index e6d3154..daaad2a 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -565,7 +565,8 @@ attributes_to_mode(DWORD attr)
 }
 
 void
-_Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag, struct _Py_stat_struct *result)
+_Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,
+                           struct _Py_stat_struct *result)
 {
     memset(result, 0, sizeof(*result));
     result->st_mode = attributes_to_mode(info->dwFileAttributes);
@@ -595,9 +596,12 @@ _Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,
    files larger than 2 GB.  fstat() may fail with EOVERFLOW on files larger
    than 2 GB because the file size type is an signed 32-bit integer: see issue
    #23152.
-   */
+
+   On Windows, set the last Windows error and return nonzero on error. On
+   POSIX, set errno and return nonzero on error. Fill status and return 0 on
+   success. */
 int
-_Py_fstat(int fd, struct _Py_stat_struct *result)
+_Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
 {
 #ifdef MS_WINDOWS
     BY_HANDLE_FILE_INFORMATION info;
@@ -619,22 +623,21 @@ _Py_fstat(int fd, struct _Py_stat_struct *result)
         SetLastError(ERROR_INVALID_HANDLE);
         return -1;
     }
-    memset(result, 0, sizeof(*result));
+    memset(status, 0, sizeof(*status));
 
     type = GetFileType(h);
     if (type == FILE_TYPE_UNKNOWN) {
         DWORD error = GetLastError();
-        if (error != 0) {
+        if (error != 0)
             return -1;
-        }
         /* else: valid but unknown file */
     }
 
     if (type != FILE_TYPE_DISK) {
         if (type == FILE_TYPE_CHAR)
-            result->st_mode = _S_IFCHR;
+            status->st_mode = _S_IFCHR;
         else if (type == FILE_TYPE_PIPE)
-            result->st_mode = _S_IFIFO;
+            status->st_mode = _S_IFIFO;
         return 0;
     }
 
@@ -642,15 +645,48 @@ _Py_fstat(int fd, struct _Py_stat_struct *result)
         return -1;
     }
 
-    _Py_attribute_data_to_stat(&info, 0, result);
+    _Py_attribute_data_to_stat(&info, 0, status);
     /* specific to fstat() */
-    result->st_ino = (((__int64)info.nFileIndexHigh)<<32) + info.nFileIndexLow;
+    status->st_ino = (((__int64)info.nFileIndexHigh)<<32) + info.nFileIndexLow;
     return 0;
 #else
-    return fstat(fd, result);
+    return fstat(fd, status);
 #endif
 }
 
+/* Return information about a file.
+
+   On POSIX, use fstat().
+
+   On Windows, use GetFileType() and GetFileInformationByHandle() which support
+   files larger than 2 GB.  fstat() may fail with EOVERFLOW on files larger
+   than 2 GB because the file size type is an signed 32-bit integer: see issue
+   #23152.
+
+   Raise an exception and return -1 on error. On Windows, set the last Windows
+   error on error. On POSIX, set errno on error. Fill status and return 0 on
+   success.
+
+   The GIL must be held. */
+int
+_Py_fstat(int fd, struct _Py_stat_struct *status)
+{
+    int res;
+
+    Py_BEGIN_ALLOW_THREADS
+    res = _Py_fstat_noraise(fd, status);
+    Py_END_ALLOW_THREADS
+
+    if (res != 0) {
+#ifdef MS_WINDOWS
+        PyErr_SetFromWindowsErr(0);
+#else
+        PyErr_SetFromErrno(PyExc_OSError);
+#endif
+        return -1;
+    }
+    return 0;
+}
 
 /* Call _wstat() on Windows, or encode the path to the filesystem encoding and
    call stat() otherwise. Only fill st_mode attribute on Windows.
diff --git a/Python/marshal.c b/Python/marshal.c
index 3472882..f89cd04 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -1486,7 +1486,7 @@ static off_t
 getfilesize(FILE *fp)
 {
     struct _Py_stat_struct st;
-    if (_Py_fstat(fileno(fp), &st) != 0)
+    if (_Py_fstat_noraise(fileno(fp), &st) != 0)
         return -1;
 #if SIZEOF_OFF_T == 4
     else if (st.st_size >= INT_MAX)
diff --git a/Python/random.c b/Python/random.c
index a281829..a4eba3c 100644
--- a/Python/random.c
+++ b/Python/random.c
@@ -221,7 +221,7 @@ dev_urandom_python(char *buffer, Py_ssize_t size)
 
     if (urandom_cache.fd >= 0) {
         /* Does the fd point to the same thing as before? (issue #21207) */
-        if (_Py_fstat(urandom_cache.fd, &st)
+        if (_Py_fstat_noraise(urandom_cache.fd, &st)
             || st.st_dev != urandom_cache.st_dev
             || st.st_ino != urandom_cache.st_ino) {
             /* Something changed: forget the cached fd (but don't close it,
@@ -250,7 +250,6 @@ dev_urandom_python(char *buffer, Py_ssize_t size)
         }
         else {
             if (_Py_fstat(fd, &st)) {
-                PyErr_SetFromErrno(PyExc_OSError);
                 close(fd);
                 return -1;
             }
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 471389c..9ec2521 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1690,7 +1690,7 @@ _PySys_Init(void)
 #if !defined(MS_WINDOWS)
     {
         struct _Py_stat_struct sb;
-        if (_Py_fstat(fileno(stdin), &sb) == 0 &&
+        if (_Py_fstat_noraise(fileno(stdin), &sb) == 0 &&
             S_ISDIR(sb.st_mode)) {
             /* There's nothing more we can do. */
             /* Py_FatalError() will core dump, so just exit. */