xref: /freebsd/lib/libc/stdio/fclose.c (revision 1d386b48a555f61cb7325543adbbb5c3f3407a66)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993 The Regents of the University of California.
5  * Copyright (c) 2013 Mariusz Zaborski <oshogbo@FreeBSD.org>
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Chris Torek.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char sccsid[] = "@(#)fclose.c	8.1 (Berkeley) 6/4/93";
38 #endif /* LIBC_SCCS and not lint */
39 #include <sys/cdefs.h>
40 #include "namespace.h"
41 #include <errno.h>
42 #include <stdbool.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include "un-namespace.h"
46 #include <spinlock.h>
47 #include "libc_private.h"
48 #include "local.h"
49 
50 static int
51 cleanfile(FILE *fp, bool c)
52 {
53 	int r;
54 
55 	r = fp->_flags & __SWR ? __sflush(fp) : 0;
56 	if (c) {
57 		if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
58 			r = EOF;
59 	}
60 
61 	if (fp->_flags & __SMBF)
62 		free((char *)fp->_bf._base);
63 	if (HASUB(fp))
64 		FREEUB(fp);
65 	if (HASLB(fp))
66 		FREELB(fp);
67 	fp->_file = -1;
68 	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
69 
70 	/*
71 	 * Lock the spinlock used to protect __sglue list walk in
72 	 * __sfp().  The __sfp() uses fp->_flags == 0 test as an
73 	 * indication of the unused FILE.
74 	 *
75 	 * Taking the lock prevents possible compiler or processor
76 	 * reordering of the writes performed before the final _flags
77 	 * cleanup, making sure that we are done with the FILE before
78 	 * it is considered available.
79 	 */
80 	STDIO_THREAD_LOCK();
81 	fp->_flags = 0;		/* Release this FILE for reuse. */
82 	STDIO_THREAD_UNLOCK();
83 
84 	return (r);
85 }
86 
87 int
88 fdclose(FILE *fp, int *fdp)
89 {
90 	int r, err;
91 
92 	if (fdp != NULL)
93 		*fdp = -1;
94 
95 	if (fp->_flags == 0) {	/* not open! */
96 		errno = EBADF;
97 		return (EOF);
98 	}
99 
100 	FLOCKFILE_CANCELSAFE(fp);
101 	r = 0;
102 	if (fp->_close != __sclose) {
103 		r = EOF;
104 		errno = EOPNOTSUPP;
105 	} else if (fp->_file < 0) {
106 		r = EOF;
107 		errno = EBADF;
108 	}
109 	if (r == EOF) {
110 		err = errno;
111 		(void)cleanfile(fp, true);
112 		errno = err;
113 	} else {
114 		if (fdp != NULL)
115 			*fdp = fp->_file;
116 		r = cleanfile(fp, false);
117 	}
118 	FUNLOCKFILE_CANCELSAFE();
119 
120 	return (r);
121 }
122 
123 int
124 fclose(FILE *fp)
125 {
126 	int r;
127 
128 	if (fp->_flags == 0) {	/* not open! */
129 		errno = EBADF;
130 		return (EOF);
131 	}
132 
133 	FLOCKFILE_CANCELSAFE(fp);
134 	r = cleanfile(fp, true);
135 	FUNLOCKFILE_CANCELSAFE();
136 
137 	return (r);
138 }
139