Re: [PATCH v2] newlib: libc: Fix bugs in the commit 3d94e07c49b5.

Corinna Vinschen <[email protected]> Wed, 15 Nov 2023 17:31:39 +0100

Newsgroups	gmane.comp.lib.newlib
Message-ID	<[email protected]>

Hi Takashi,

On Nov 13 14:07, Corinna Vinschen wrote:
> On Nov 11 01:09, Takashi Yano wrote:
> > diff --git a/newlib/libc/stdio/ungetc.c b/newlib/libc/stdio/ungetc.c
> > index 79914af08..5053fd6c4 100644
> > --- a/newlib/libc/stdio/ungetc.c
> > +++ b/newlib/libc/stdio/ungetc.c
> > @@ -125,12 +125,6 @@ _ungetc_r (struct _reent *rptr,
> >  
> >    _newlib_flockfile_start (fp);
> >  
> > -  if (ORIENT (fp, -1) != -1)
> > -    {
> > -      _newlib_flockfile_exit (fp);
> > -      return EOF;
> > -    }
> > -
> >    /* After ungetc, we won't be at eof anymore */
> >    fp->_flags &= ~__SEOF;
> >  
> > @@ -213,6 +207,8 @@ int
> >  ungetc (int c,
> >         register FILE *fp)
> >  {
> > +  if (ORIENT (fp, -1) != -1)
> > +    return EOF;
> >    return _ungetc_r (_REENT, c, fp);
> >  }
> >  #endif /* !_REENT_ONLY */
> 
> As per the reasoning in terms of old standards, we shouldn't check or set
> the orientation in ungetc at all.

Given all that has been discussed, I attached a followup proposal.
I hope that's ok.  We may want to release 3.4.10 in the next weeks.


Thanks,
Corinna

0001-newlib-libc-Fix-bugs-in-the-commit-3d94e07c49b5.patch (text/plain, 16.7 KB)

From 528fcc9624a505c365cdb120e0dc0f0eee60398c Mon Sep 17 00:00:00 2001
From: Takashi Yano <[email protected]>
Date: Sat, 11 Nov 2023 01:09:47 +0900
Subject: [PATCH v3] newlib: libc: Fix bugs in the commit 3d94e07c49b5.

The commit 3d94e07c49b5 has a few bugs which cause testsuite failure
in libstdc++. This is due to excess orientation check in __srefill_r()
and _ungetc_r(). Further, sscanf() family also calls ssvfscanf() family
with fp->_file == -1. This causes undesired orientation set/check for
sscanf() family. This patch fixes these problems.

Also, as in GLibC, do not set orientation in ungetc, and only set, but
do not check orientation in ungetwc.

Fixes: 3d94e07c49b5 ("newlib: libc: Fix crash on fprintf to a wide-oriented stream.")
Reported-by: Christophe Lyon <[email protected]>
Reported-by: Joel Sherrill <[email protected]>
Co-developed-by: Corinna Vinschen <[email protected]>
Signed-off-by: Takashi Yano <[email protected]>
Signed-off-by: Corinna Vinschen <[email protected]>
---
 newlib/libc/stdio/asiprintf.c   | 2 ++
 newlib/libc/stdio/asniprintf.c  | 2 ++
 newlib/libc/stdio/asnprintf.c   | 2 ++
 newlib/libc/stdio/asprintf.c    | 2 ++
 newlib/libc/stdio/getc.c        | 6 ++++++
 newlib/libc/stdio/refill.c      | 3 ---
 newlib/libc/stdio/siprintf.c    | 2 ++
 newlib/libc/stdio/siscanf.c     | 2 ++
 newlib/libc/stdio/sniprintf.c   | 2 ++
 newlib/libc/stdio/snprintf.c    | 2 ++
 newlib/libc/stdio/sprintf.c     | 2 ++
 newlib/libc/stdio/sscanf.c      | 2 ++
 newlib/libc/stdio/swprintf.c    | 2 ++
 newlib/libc/stdio/swscanf.c     | 2 ++
 newlib/libc/stdio/ungetc.c      | 6 ------
 newlib/libc/stdio/ungetwc.c     | 1 +
 newlib/libc/stdio/vasiprintf.c  | 1 +
 newlib/libc/stdio/vasniprintf.c | 1 +
 newlib/libc/stdio/vasnprintf.c  | 1 +
 newlib/libc/stdio/vasprintf.c   | 1 +
 newlib/libc/stdio/vsiprintf.c   | 1 +
 newlib/libc/stdio/vsiscanf.c    | 1 +
 newlib/libc/stdio/vsniprintf.c  | 1 +
 newlib/libc/stdio/vsnprintf.c   | 1 +
 newlib/libc/stdio/vsprintf.c    | 1 +
 newlib/libc/stdio/vsscanf.c     | 1 +
 newlib/libc/stdio/vswprintf.c   | 1 +
 27 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/newlib/libc/stdio/asiprintf.c b/newlib/libc/stdio/asiprintf.c
index af25e9a57acd..dedb7fbfabce 100644
--- a/newlib/libc/stdio/asiprintf.c
+++ b/newlib/libc/stdio/asiprintf.c
@@ -35,6 +35,7 @@ _asiprintf_r (struct _reent *ptr,
 
   /* mark a zero-length reallocatable buffer */
   f._flags = __SWR | __SSTR | __SMBF;
+  f._flags2 = 0;
   f._bf._base = f._p = NULL;
   f._bf._size = f._w = 0;
   f._file = -1;  /* No file. */
@@ -61,6 +62,7 @@ asiprintf (char **strp,
 
   /* mark a zero-length reallocatable buffer */
   f._flags = __SWR | __SSTR | __SMBF;
+  f._flags2 = 0;
   f._bf._base = f._p = NULL;
   f._bf._size = f._w = 0;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/asniprintf.c b/newlib/libc/stdio/asniprintf.c
index 97e77748e75d..e930c8d69f64 100644
--- a/newlib/libc/stdio/asniprintf.c
+++ b/newlib/libc/stdio/asniprintf.c
@@ -36,6 +36,7 @@ _asniprintf_r (struct _reent *ptr,
       len = 0;
       buf = NULL;
     }
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) buf;
   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
      FIXME - it would be nice to rewrite sys/reent.h to support size_t
@@ -82,6 +83,7 @@ asniprintf (char *buf,
       len = 0;
       buf = NULL;
     }
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) buf;
   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
      FIXME - it would be nice to rewrite sys/reent.h to support size_t
diff --git a/newlib/libc/stdio/asnprintf.c b/newlib/libc/stdio/asnprintf.c
index f82556143e74..4c9ad586020a 100644
--- a/newlib/libc/stdio/asnprintf.c
+++ b/newlib/libc/stdio/asnprintf.c
@@ -36,6 +36,7 @@ _asnprintf_r (struct _reent *__restrict ptr,
       len = 0;
       buf = NULL;
     }
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) buf;
   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
      FIXME - it would be nice to rewrite sys/reent.h to support size_t
@@ -88,6 +89,7 @@ asnprintf (char *__restrict buf,
       len = 0;
       buf = NULL;
     }
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) buf;
   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
      FIXME - it would be nice to rewrite sys/reent.h to support size_t
diff --git a/newlib/libc/stdio/asprintf.c b/newlib/libc/stdio/asprintf.c
index 542e70e4c308..511d0e0f3f4a 100644
--- a/newlib/libc/stdio/asprintf.c
+++ b/newlib/libc/stdio/asprintf.c
@@ -35,6 +35,7 @@ _asprintf_r (struct _reent *ptr,
 
   /* mark a zero-length reallocatable buffer */
   f._flags = __SWR | __SSTR | __SMBF;
+  f._flags2 = 0;
   f._bf._base = f._p = NULL;
   f._bf._size = f._w = 0;
   f._file = -1;  /* No file. */
@@ -67,6 +68,7 @@ asprintf (char **__restrict strp,
 
   /* mark a zero-length reallocatable buffer */
   f._flags = __SWR | __SSTR | __SMBF;
+  f._flags2 = 0;
   f._bf._base = f._p = NULL;
   f._bf._size = f._w = 0;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/getc.c b/newlib/libc/stdio/getc.c
index c8781320e603..12bffaf8f79a 100644
--- a/newlib/libc/stdio/getc.c
+++ b/newlib/libc/stdio/getc.c
@@ -81,6 +81,9 @@ _getc_r (struct _reent *ptr,
 {
   int result;
   CHECK_INIT (ptr, fp);
+  if (ORIENT (fp, -1) != -1)
+    return EOF;
+
   _newlib_flockfile_start (fp);
   result = __sgetc_r (ptr, fp);
   _newlib_flockfile_end (fp);
@@ -96,6 +99,9 @@ getc (register FILE *fp)
   struct _reent *reent = _REENT;
 
   CHECK_INIT (reent, fp);
+  if (ORIENT (fp, -1) != -1)
+    return EOF;
+
   _newlib_flockfile_start (fp);
   result = __sgetc_r (reent, fp);
   _newlib_flockfile_end (fp);
diff --git a/newlib/libc/stdio/refill.c b/newlib/libc/stdio/refill.c
index c1ef7e120b71..cd71ed1529ba 100644
--- a/newlib/libc/stdio/refill.c
+++ b/newlib/libc/stdio/refill.c
@@ -43,9 +43,6 @@ __srefill_r (struct _reent * ptr,
 
   CHECK_INIT (ptr, fp);
 
-  if (ORIENT (fp, -1) != -1)
-    return EOF;
-
   fp->_r = 0;			/* largely a convenience for callers */
 
   /* SysV does not make this test; take it out for compatibility */
diff --git a/newlib/libc/stdio/siprintf.c b/newlib/libc/stdio/siprintf.c
index bd29edd88110..b337925979bb 100644
--- a/newlib/libc/stdio/siprintf.c
+++ b/newlib/libc/stdio/siprintf.c
@@ -108,6 +108,7 @@ _siprintf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = INT_MAX;
   f._file = -1;  /* No file. */
@@ -129,6 +130,7 @@ siprintf (char *str,
   FILE f;
 
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = INT_MAX;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/siscanf.c b/newlib/libc/stdio/siscanf.c
index b88b81088818..4c1363d0a766 100644
--- a/newlib/libc/stdio/siscanf.c
+++ b/newlib/libc/stdio/siscanf.c
@@ -90,6 +90,7 @@ siscanf (const char *str,
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = strlen (str);
   f._read = __seofread;
@@ -114,6 +115,7 @@ _siscanf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = strlen (str);
   f._read = __seofread;
diff --git a/newlib/libc/stdio/sniprintf.c b/newlib/libc/stdio/sniprintf.c
index b05ffcb12da9..852713f1ffb8 100644
--- a/newlib/libc/stdio/sniprintf.c
+++ b/newlib/libc/stdio/sniprintf.c
@@ -42,6 +42,7 @@ _sniprintf_r (struct _reent *ptr,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? size - 1 : 0);
   f._file = -1;  /* No file. */
@@ -73,6 +74,7 @@ sniprintf (char *str,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? size - 1 : 0);
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/snprintf.c b/newlib/libc/stdio/snprintf.c
index 4a3084beacb3..b6130b998393 100644
--- a/newlib/libc/stdio/snprintf.c
+++ b/newlib/libc/stdio/snprintf.c
@@ -41,6 +41,7 @@ _snprintf_r (struct _reent *ptr,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? size - 1 : 0);
   f._file = -1;  /* No file. */
@@ -78,6 +79,7 @@ snprintf (char *__restrict str,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? size - 1 : 0);
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/sprintf.c b/newlib/libc/stdio/sprintf.c
index be66ec6f5d73..92cae46189df 100644
--- a/newlib/libc/stdio/sprintf.c
+++ b/newlib/libc/stdio/sprintf.c
@@ -584,6 +584,7 @@ _sprintf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = INT_MAX;
   f._file = -1;  /* No file. */
@@ -611,6 +612,7 @@ sprintf (char *__restrict str,
   FILE f;
 
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = INT_MAX;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/sscanf.c b/newlib/libc/stdio/sscanf.c
index 9c50361bc026..52145fc46c20 100644
--- a/newlib/libc/stdio/sscanf.c
+++ b/newlib/libc/stdio/sscanf.c
@@ -429,6 +429,7 @@ sscanf (const char *__restrict str,
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = strlen (str);
   f._read = __seofread;
@@ -459,6 +460,7 @@ _sscanf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = strlen (str);
   f._read = __seofread;
diff --git a/newlib/libc/stdio/swprintf.c b/newlib/libc/stdio/swprintf.c
index 634b22beb909..e590b522ced8 100644
--- a/newlib/libc/stdio/swprintf.c
+++ b/newlib/libc/stdio/swprintf.c
@@ -568,6 +568,7 @@ _swprintf_r (struct _reent *ptr,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? (size - 1) * sizeof (wchar_t) : 0);
   f._file = -1;  /* No file. */
@@ -608,6 +609,7 @@ swprintf (wchar_t *__restrict str,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? (size - 1) * sizeof (wchar_t) : 0);
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/swscanf.c b/newlib/libc/stdio/swscanf.c
index 578ac3c93f76..0ef4d0ebde18 100644
--- a/newlib/libc/stdio/swscanf.c
+++ b/newlib/libc/stdio/swscanf.c
@@ -422,6 +422,7 @@ swscanf (const wchar_t *__restrict str, const wchar_t *__restrict fmt, ...)
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = wcslen (str) * sizeof (wchar_t);
   f._read = __seofread;
@@ -446,6 +447,7 @@ _swscanf_r (struct _reent *ptr, const wchar_t *str, const wchar_t *fmt, ...)
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = wcslen (str) * sizeof (wchar_t);
   f._read = __seofread;
diff --git a/newlib/libc/stdio/ungetc.c b/newlib/libc/stdio/ungetc.c
index 79914af0806e..8b10c8218616 100644
--- a/newlib/libc/stdio/ungetc.c
+++ b/newlib/libc/stdio/ungetc.c
@@ -125,12 +125,6 @@ _ungetc_r (struct _reent *rptr,
 
   _newlib_flockfile_start (fp);
 
-  if (ORIENT (fp, -1) != -1)
-    {
-      _newlib_flockfile_exit (fp);
-      return EOF;
-    }
-
   /* After ungetc, we won't be at eof anymore */
   fp->_flags &= ~__SEOF;
 
diff --git a/newlib/libc/stdio/ungetwc.c b/newlib/libc/stdio/ungetwc.c
index 18636d773edd..1d65a1ef039a 100644
--- a/newlib/libc/stdio/ungetwc.c
+++ b/newlib/libc/stdio/ungetwc.c
@@ -112,5 +112,6 @@ ungetwc (wint_t wc,
   struct _reent *reent = _REENT;
 
   CHECK_INIT (reent, fp);
+  ORIENT (fp, 1);
   return _ungetwc_r (reent, wc, fp);
 }
diff --git a/newlib/libc/stdio/vasiprintf.c b/newlib/libc/stdio/vasiprintf.c
index 1deb2dbcf3d8..d9c11eaf503f 100644
--- a/newlib/libc/stdio/vasiprintf.c
+++ b/newlib/libc/stdio/vasiprintf.c
@@ -50,6 +50,7 @@ _vasiprintf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SWR | __SSTR | __SMBF ;
+  f._flags2 = 0;
   f._bf._base = f._p = NULL;
   f._bf._size = f._w = 0;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/vasniprintf.c b/newlib/libc/stdio/vasniprintf.c
index b24cd96fb625..c85ca06e8c1a 100644
--- a/newlib/libc/stdio/vasniprintf.c
+++ b/newlib/libc/stdio/vasniprintf.c
@@ -36,6 +36,7 @@ _vasniprintf_r (struct _reent *ptr,
       len = 0;
       buf = NULL;
     }
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) buf;
   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
      FIXME - it would be nice to rewrite sys/reent.h to support size_t
diff --git a/newlib/libc/stdio/vasnprintf.c b/newlib/libc/stdio/vasnprintf.c
index b3787ec7a1fa..02f55caa9a95 100644
--- a/newlib/libc/stdio/vasnprintf.c
+++ b/newlib/libc/stdio/vasnprintf.c
@@ -36,6 +36,7 @@ _vasnprintf_r (struct _reent *ptr,
       len = 0;
       buf = NULL;
     }
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) buf;
   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
      FIXME - it would be nice to rewrite sys/reent.h to support size_t
diff --git a/newlib/libc/stdio/vasprintf.c b/newlib/libc/stdio/vasprintf.c
index d7ec9c8400ef..b466936bd94b 100644
--- a/newlib/libc/stdio/vasprintf.c
+++ b/newlib/libc/stdio/vasprintf.c
@@ -56,6 +56,7 @@ _vasprintf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SWR | __SSTR | __SMBF ;
+  f._flags2 = 0;
   f._bf._base = f._p = NULL;
   f._bf._size = f._w = 0;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/vsiprintf.c b/newlib/libc/stdio/vsiprintf.c
index 8128cb772684..af07ad85e8cd 100644
--- a/newlib/libc/stdio/vsiprintf.c
+++ b/newlib/libc/stdio/vsiprintf.c
@@ -50,6 +50,7 @@ _vsiprintf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = INT_MAX;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/vsiscanf.c b/newlib/libc/stdio/vsiscanf.c
index d7135ef71278..4e28d1079390 100644
--- a/newlib/libc/stdio/vsiscanf.c
+++ b/newlib/libc/stdio/vsiscanf.c
@@ -49,6 +49,7 @@ _vsiscanf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = strlen (str);
   f._read = __seofread;
diff --git a/newlib/libc/stdio/vsniprintf.c b/newlib/libc/stdio/vsniprintf.c
index e7625ffd5345..a50a0a993115 100644
--- a/newlib/libc/stdio/vsniprintf.c
+++ b/newlib/libc/stdio/vsniprintf.c
@@ -58,6 +58,7 @@ _vsniprintf_r (struct _reent *ptr,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? size - 1 : 0);
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/vsnprintf.c b/newlib/libc/stdio/vsnprintf.c
index ecf82eaefff7..d9c72b526ba5 100644
--- a/newlib/libc/stdio/vsnprintf.c
+++ b/newlib/libc/stdio/vsnprintf.c
@@ -64,6 +64,7 @@ _vsnprintf_r (struct _reent *ptr,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? size - 1 : 0);
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/vsprintf.c b/newlib/libc/stdio/vsprintf.c
index 4d51fd0dc03f..4d4619fd0324 100644
--- a/newlib/libc/stdio/vsprintf.c
+++ b/newlib/libc/stdio/vsprintf.c
@@ -56,6 +56,7 @@ _vsprintf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = INT_MAX;
   f._file = -1;  /* No file. */
diff --git a/newlib/libc/stdio/vsscanf.c b/newlib/libc/stdio/vsscanf.c
index e9e84088f7cf..6150f541bb24 100644
--- a/newlib/libc/stdio/vsscanf.c
+++ b/newlib/libc/stdio/vsscanf.c
@@ -55,6 +55,7 @@ _vsscanf_r (struct _reent *ptr,
   FILE f;
 
   f._flags = __SRD | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._r = strlen (str);
   f._read = __seofread;
diff --git a/newlib/libc/stdio/vswprintf.c b/newlib/libc/stdio/vswprintf.c
index 08a8545baef8..ab2e52ff4921 100644
--- a/newlib/libc/stdio/vswprintf.c
+++ b/newlib/libc/stdio/vswprintf.c
@@ -46,6 +46,7 @@ _vswprintf_r (struct _reent *ptr,
       return EOF;
     }
   f._flags = __SWR | __SSTR;
+  f._flags2 = 0;
   f._bf._base = f._p = (unsigned char *) str;
   f._bf._size = f._w = (size > 0 ? (size - 1) * sizeof (wchar_t) : 0);
   f._file = -1;  /* No file. */
-- 
2.41.0
:q