Fix the handle locking in stdio to use flockfile/funlockfile

internally when and where required.  Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking.  A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization.  Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.

ok kurt@, earlier version tested by sthen@ and jj@

1 files changed, 9 insertions, 3 deletions

diff --git a/lib/libc/stdio/vfscanf.c b/lib/libc/stdio/vfscanf.c
index 7e05f1ac567..3a579b19a02 100644
--- a/lib/libc/stdio/vfscanf.c
+++ b/lib/libc/stdio/vfscanf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfscanf.c,v 1.22 2009/04/05 19:29:28 martynas Exp $ */
+/*	$OpenBSD: vfscanf.c,v 1.23 2009/10/21 16:04:23 guenther Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -117,6 +117,7 @@ VFSCANF(FILE *fp, const char *fmt0, __va_list ap)
 	static short basefix[17] =
 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
 
+	FLOCKFILE(fp);
 	_SET_ORIENTATION(fp, -1);
 
 	nassigned = 0;
@@ -124,8 +125,10 @@ VFSCANF(FILE *fp, const char *fmt0, __va_list ap)
 	base = 0;		/* XXX just to keep gcc happy */
 	for (;;) {
 		c = *fmt++;
-		if (c == 0)
+		if (c == 0) {
+			FUNLOCKFILE(fp);
 			return (nassigned);
+		}
 		if (isspace(c)) {
 			while ((fp->_r > 0 || __srefill(fp) == 0) &&
 			    isspace(*fp->_p))
@@ -293,6 +296,7 @@ literal:
 		 * Disgusting backwards compatibility hacks.	XXX
 		 */
 		case '\0':	/* compat */
+			FUNLOCKFILE(fp);
 			return (EOF);
 
 		default:	/* compat */
@@ -690,8 +694,10 @@ literal:
 		}
 	}
 input_failure:
-	return (nassigned ? nassigned : -1);
+	if (nassigned == 0)
+		nassigned = -1;
 match_failure:
+	FUNLOCKFILE(fp);
 	return (nassigned);
 }