File: | src/lib/libc/stdio/ungetc.c |
Warning: | line 111, column 6 Dereference of null pointer |
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1 | /* $OpenBSD: ungetc.c,v 1.15 2016/09/21 04:38:56 guenther Exp $ */ | |||
2 | /*- | |||
3 | * Copyright (c) 1990, 1993 | |||
4 | * The Regents of the University of California. All rights reserved. | |||
5 | * | |||
6 | * This code is derived from software contributed to Berkeley by | |||
7 | * Chris Torek. | |||
8 | * | |||
9 | * Redistribution and use in source and binary forms, with or without | |||
10 | * modification, are permitted provided that the following conditions | |||
11 | * are met: | |||
12 | * 1. Redistributions of source code must retain the above copyright | |||
13 | * notice, this list of conditions and the following disclaimer. | |||
14 | * 2. Redistributions in binary form must reproduce the above copyright | |||
15 | * notice, this list of conditions and the following disclaimer in the | |||
16 | * documentation and/or other materials provided with the distribution. | |||
17 | * 3. Neither the name of the University nor the names of its contributors | |||
18 | * may be used to endorse or promote products derived from this software | |||
19 | * without specific prior written permission. | |||
20 | * | |||
21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |||
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |||
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |||
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |||
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |||
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |||
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |||
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |||
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||
31 | * SUCH DAMAGE. | |||
32 | */ | |||
33 | ||||
34 | #include <stdio.h> | |||
35 | #include <stdlib.h> | |||
36 | #include <string.h> | |||
37 | #include "local.h" | |||
38 | ||||
39 | static int __submore(FILE *); | |||
40 | /* | |||
41 | * Expand the ungetc buffer `in place'. That is, adjust fp->_p when | |||
42 | * the buffer moves, so that it points the same distance from the end, | |||
43 | * and move the bytes in the buffer around as necessary so that they | |||
44 | * are all at the end (stack-style). | |||
45 | */ | |||
46 | static int | |||
47 | __submore(FILE *fp) | |||
48 | { | |||
49 | int i; | |||
50 | unsigned char *p; | |||
51 | ||||
52 | if (_UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._base == fp->_ubuf) { | |||
53 | /* | |||
54 | * Get a new buffer (rather than expanding the old one). | |||
55 | */ | |||
56 | if ((p = malloc(BUFSIZ1024)) == NULL((void *)0)) | |||
57 | return (EOF(-1)); | |||
58 | _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._base = p; | |||
59 | _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._size = BUFSIZ1024; | |||
60 | p += BUFSIZ1024 - sizeof(fp->_ubuf); | |||
61 | for (i = sizeof(fp->_ubuf); --i >= 0;) | |||
62 | p[i] = fp->_ubuf[i]; | |||
63 | fp->_p = p; | |||
64 | return (0); | |||
65 | } | |||
66 | i = _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._size; | |||
67 | p = reallocarray(_UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._base, i, 2); | |||
68 | if (p == NULL((void *)0)) | |||
69 | return (EOF(-1)); | |||
70 | /* no overlap (hence can use memcpy) because we doubled the size */ | |||
71 | (void)memcpy(p + i, p, i); | |||
72 | fp->_p = p + i; | |||
73 | _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._base = p; | |||
74 | _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._size = i * 2; | |||
75 | return (0); | |||
76 | } | |||
77 | ||||
78 | int | |||
79 | ungetc(int c, FILE *fp) | |||
80 | { | |||
81 | if (c == EOF(-1)) | |||
| ||||
82 | return (EOF(-1)); | |||
83 | if (!__sdidinit) | |||
84 | __sinit(); | |||
85 | FLOCKFILE(fp)do { if (_thread_cb.tc_flockfile != ((void *)0)) _thread_cb.tc_flockfile (fp); } while (0); | |||
86 | _SET_ORIENTATION(fp, -1)do { struct wchar_io_data *_wcio = (((struct __sfileext *)((fp )->_ext._base)) ? &(((struct __sfileext *)((fp)->_ext ._base))->_wcio) : (struct wchar_io_data *)0); if (_wcio && _wcio->wcio_mode == 0) _wcio->wcio_mode = (-1);} while (0); | |||
87 | if ((fp->_flags & __SRD0x0004) == 0) { | |||
88 | /* | |||
89 | * Not already reading: no good unless reading-and-writing. | |||
90 | * Otherwise, flush any current write stuff. | |||
91 | */ | |||
92 | if ((fp->_flags & __SRW0x0010) == 0) { | |||
93 | error: FUNLOCKFILE(fp)do { if (_thread_cb.tc_funlockfile != ((void *)0)) _thread_cb .tc_funlockfile(fp); } while (0); | |||
94 | return (EOF(-1)); | |||
95 | } | |||
96 | if (fp->_flags & __SWR0x0008) { | |||
97 | if (__sflush(fp)) | |||
98 | goto error; | |||
99 | fp->_flags &= ~__SWR0x0008; | |||
100 | fp->_w = 0; | |||
101 | fp->_lbfsize = 0; | |||
102 | } | |||
103 | fp->_flags |= __SRD0x0004; | |||
104 | } | |||
105 | c = (unsigned char)c; | |||
106 | ||||
107 | /* | |||
108 | * If we are in the middle of ungetc'ing, just continue. | |||
109 | * This may require expanding the current ungetc buffer. | |||
110 | */ | |||
111 | if (HASUB(fp)(((struct __sfileext *)((fp)->_ext._base))->_ub._base != ((void *)0))) { | |||
| ||||
112 | if (fp->_r >= _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._size && __submore(fp)) | |||
113 | goto error; | |||
114 | *--fp->_p = c; | |||
115 | inc_ret: fp->_r++; | |||
116 | FUNLOCKFILE(fp)do { if (_thread_cb.tc_funlockfile != ((void *)0)) _thread_cb .tc_funlockfile(fp); } while (0); | |||
117 | return (c); | |||
118 | } | |||
119 | fp->_flags &= ~__SEOF0x0020; | |||
120 | ||||
121 | /* | |||
122 | * If we can handle this by simply backing up, do so, | |||
123 | * but never replace the original character. | |||
124 | * (This makes sscanf() work when scanning `const' data.) | |||
125 | */ | |||
126 | if (fp->_bf._base != NULL((void *)0) && fp->_p > fp->_bf._base && | |||
127 | fp->_p[-1] == c) { | |||
128 | fp->_p--; | |||
129 | goto inc_ret; | |||
130 | } | |||
131 | ||||
132 | /* | |||
133 | * Create an ungetc buffer. | |||
134 | * Initially, we will use the `reserve' buffer. | |||
135 | */ | |||
136 | fp->_ur = fp->_r; | |||
137 | fp->_up = fp->_p; | |||
138 | _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._base = fp->_ubuf; | |||
139 | _UB(fp)((struct __sfileext *)((fp)->_ext._base))->_ub._size = sizeof(fp->_ubuf); | |||
140 | fp->_ubuf[sizeof(fp->_ubuf) - 1] = c; | |||
141 | fp->_p = &fp->_ubuf[sizeof(fp->_ubuf) - 1]; | |||
142 | fp->_r = 1; | |||
143 | FUNLOCKFILE(fp)do { if (_thread_cb.tc_funlockfile != ((void *)0)) _thread_cb .tc_funlockfile(fp); } while (0); | |||
144 | return (c); | |||
145 | } | |||
146 | DEF_STRONG(ungetc)__asm__(".global " "ungetc" " ; " "ungetc" " = " "_libc_ungetc" ); |