libio: Avoid RMW of flags2 outside lock (BZ #27842)

Remove an unconditional RMW on flags2 in flockfile - we don't need to change
_IO_FLAGS2_NEED_LOCK since it isn't used in flockfile or funlockfile.
This fixes BZ #27842.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

diff --git a/stdio-common/flockfile.c b/stdio-common/flockfile.c
index a5decb450f8d477e3105d02661282afeab58f88b..49f72c69ab7a4ccca6f21d443c6fc3a0eca76376 100644 (file)
--- a/stdio-common/flockfile.c
+++ b/stdio-common/flockfile.c
@@ -22,7 +22,6 @@
 void
 __flockfile (FILE *stream)
 {
-  stream->_flags2 |= _IO_FLAGS2_NEED_LOCK;
   _IO_lock_lock (*stream->_lock);
 }
 weak_alias (__flockfile, flockfile);