* fhandler_disk_file.cc (fhandler_base::fstat_helper): Rewrite checking

	for executable file magic using a thread safe method and re-enable this
	code.

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index f1caebe..0db674f 100644 (file)
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,11 @@
 2007-08-21  Corinna Vinschen  <corinna@vinschen.de>
 
+       * fhandler_disk_file.cc (fhandler_base::fstat_helper): Rewrite checking
+       for executable file magic using a thread safe method and re-enable this
+       code.
+
+2007-08-21  Corinna Vinschen  <corinna@vinschen.de>
+
        * syscalls.cc (unlink_nt): Drop one local FILE_BASIC_INFORMATION struct.
 
 2007-08-21  Corinna Vinschen  <corinna@vinschen.de>

diff --git a/winsup/cygwin/fhandler_disk_file.cc b/winsup/cygwin/fhandler_disk_file.cc
index 164e9a0..c7c5d9f 100644 (file)
--- a/winsup/cygwin/fhandler_disk_file.cc
+++ b/winsup/cygwin/fhandler_disk_file.cc
@@ -570,37 +570,31 @@ fhandler_base::fstat_helper (struct __stat64 *buf,
       else
        {
          buf->st_mode |= S_IFREG;
-#if 0
-         /* FIXME: Is this code really necessary?  There are already
-            two places in path_conv which look for executability.
-            Also, by using the fhandler's io HANDLE, a stat call might
-            change the file position for a short period of time in
-            a not thread-safe way. */
          if (pc.exec_state () == dont_know_if_executable)
            {
-             DWORD cur, done;
-             LONG curhigh = 0;
-             char magic[3];
-
-             /* First retrieve current position, set to beginning
-                of file if not already there. */
-             cur = SetFilePointer (get_handle (), 0, &curhigh, FILE_CURRENT);
-             if ((cur != INVALID_SET_FILE_POINTER || GetLastError () == NO_ERROR)
-                 && ((!cur && !curhigh) || SetFilePointer (get_handle (), 0, NULL, FILE_BEGIN)
-                     != INVALID_SET_FILE_POINTER))
-               {
-                 /* FIXME should we use /etc/magic ? */
-                 magic[0] = magic[1] = magic[2] = '\0';
-                 if (ReadFile (get_handle (), magic, 3, &done, NULL)
-                     && has_exec_chars (magic, done))
+             UNICODE_STRING same;
+             OBJECT_ATTRIBUTES attr;
+             HANDLE h;
+             IO_STATUS_BLOCK io;
+
+             RtlInitUnicodeString (&same, L"");
+             InitializeObjectAttributes (&attr, &same, 0, get_handle (), NULL);
+             if (NT_SUCCESS (NtOpenFile (&h, FILE_READ_DATA, &attr, &io,
+                                         FILE_SHARE_VALID_FLAGS, 0)))
+               {
+                 LARGE_INTEGER off = { QuadPart:0LL };
+                 char magic[3];
+
+                 if (NT_SUCCESS (NtReadFile (h, NULL, NULL, NULL, &io, magic,
+                                             3, &off, NULL))
+                     && has_exec_chars (magic, io.Information))
                    {
                      pc.set_exec ();
                      buf->st_mode |= STD_XBITS;
                    }
-                 SetFilePointer (get_handle (), cur, &curhigh, FILE_BEGIN);
+                 NtClose (h);
                }
            }
-#endif
        }
       if (pc.exec_state () == is_executable)
        buf->st_mode |= STD_XBITS;