diff options
Diffstat (limited to 'newlib/libc/stdio/fflush.c')
| -rw-r--r-- | newlib/libc/stdio/fflush.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/newlib/libc/stdio/fflush.c b/newlib/libc/stdio/fflush.c index a8ef755c2..d46b41f94 100644 --- a/newlib/libc/stdio/fflush.c +++ b/newlib/libc/stdio/fflush.c @@ -67,6 +67,22 @@ _DEFUN(fflush, (fp), if (fp == NULL) return _fwalk (_GLOBAL_REENT, fflush); +#ifdef _REENT_SMALL + /* For REENT_SMALL platforms, it is possible we are being + called for the first time on a std stream. This std + stream can belong to a reentrant struct that is not + _REENT. If CHECK_INIT gets called below based on _REENT, + we will end up changing said file pointers to the equivalent + std stream off of _REENT. This causes unexpected behavior if + there is any data to flush on the _REENT std stream. There + are two alternatives to fix this: 1) make a reentrant fflush + or 2) simply recognize that this file has nothing to flush + and return immediately before performing a CHECK_INIT. Choice + 2 is implemented here due to its simplicity. */ + if (fp->_bf._base == NULL) + return 0; +#endif /* _REENT_SMALL */ + CHECK_INIT (_REENT, fp); _flockfile (fp); |