hw/arm/virt: parameter passing cleanups
[qemu.git] / scripts / coverity-model.c
1 /* Coverity Scan model
2 *
3 * Copyright (C) 2014 Red Hat, Inc.
4 *
5 * Authors:
6 * Markus Armbruster <armbru@redhat.com>
7 * Paolo Bonzini <pbonzini@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or, at your
10 * option, any later version. See the COPYING file in the top-level directory.
11 */
12
13
14 /*
15 * This is the source code for our Coverity user model file. The
16 * purpose of user models is to increase scanning accuracy by explaining
17 * code Coverity can't see (out of tree libraries) or doesn't
18 * sufficiently understand. Better accuracy means both fewer false
19 * positives and more true defects. Memory leaks in particular.
20 *
21 * - A model file can't import any header files. Some built-in primitives are
22 * available but not wchar_t, NULL etc.
23 * - Modeling doesn't need full structs and typedefs. Rudimentary structs
24 * and similar types are sufficient.
25 * - An uninitialized local variable signifies that the variable could be
26 * any value.
27 *
28 * The model file must be uploaded by an admin in the analysis settings of
29 * http://scan.coverity.com/projects/378
30 */
31
32 #define NULL ((void *)0)
33
34 typedef unsigned char uint8_t;
35 typedef char int8_t;
36 typedef unsigned int uint32_t;
37 typedef int int32_t;
38 typedef long ssize_t;
39 typedef unsigned long long uint64_t;
40 typedef long long int64_t;
41 typedef _Bool bool;
42
43 typedef struct va_list_str *va_list;
44
45 /* exec.c */
46
47 typedef struct AddressSpace AddressSpace;
48 typedef uint64_t hwaddr;
49 typedef uint32_t MemTxResult;
50 typedef uint64_t MemTxAttrs;
51
52 static void __bufwrite(uint8_t *buf, ssize_t len)
53 {
54 int first, last;
55 __coverity_negative_sink__(len);
56 if (len == 0) return;
57 buf[0] = first;
58 buf[len-1] = last;
59 __coverity_writeall__(buf);
60 }
61
62 static void __bufread(uint8_t *buf, ssize_t len)
63 {
64 __coverity_negative_sink__(len);
65 if (len == 0) return;
66 int first = buf[0];
67 int last = buf[len-1];
68 }
69
70 MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
71 uint8_t *buf, int len, bool is_write)
72 {
73 MemTxResult result;
74
75 // TODO: investigate impact of treating reads as producing
76 // tainted data, with __coverity_tainted_data_argument__(buf).
77 if (is_write) __bufread(buf, len); else __bufwrite(buf, len);
78
79 return result;
80 }
81
82 /* Tainting */
83
84 typedef struct {} name2keysym_t;
85 static int get_keysym(const name2keysym_t *table,
86 const char *name)
87 {
88 int result;
89 if (result > 0) {
90 __coverity_tainted_string_sanitize_content__(name);
91 return result;
92 } else {
93 return 0;
94 }
95 }
96
97 /*
98 * GLib memory allocation functions.
99 *
100 * Note that we ignore the fact that g_malloc of 0 bytes returns NULL,
101 * and g_realloc of 0 bytes frees the pointer.
102 *
103 * Modeling this would result in Coverity flagging a lot of memory
104 * allocations as potentially returning NULL, and asking us to check
105 * whether the result of the allocation is NULL or not. However, the
106 * resulting pointer should never be dereferenced anyway, and in fact
107 * it is not in the vast majority of cases.
108 *
109 * If a dereference did happen, this would suppress a defect report
110 * for an actual null pointer dereference. But it's too unlikely to
111 * be worth wading through the false positives, and with some luck
112 * we'll get a buffer overflow reported anyway.
113 */
114
115 /*
116 * Allocation primitives, cannot return NULL
117 * See also Coverity's library/generic/libc/all/all.c
118 */
119
120 void *g_malloc_n(size_t nmemb, size_t size)
121 {
122 size_t sz;
123 void *ptr;
124
125 __coverity_negative_sink__(nmemb);
126 __coverity_negative_sink__(size);
127 sz = nmemb * size;
128 ptr = __coverity_alloc__(sz);
129 __coverity_mark_as_uninitialized_buffer__(ptr);
130 __coverity_mark_as_afm_allocated__(ptr, "g_free");
131 return ptr;
132 }
133
134 void *g_malloc0_n(size_t nmemb, size_t size)
135 {
136 size_t sz;
137 void *ptr;
138
139 __coverity_negative_sink__(nmemb);
140 __coverity_negative_sink__(size);
141 sz = nmemb * size;
142 ptr = __coverity_alloc__(sz);
143 __coverity_writeall0__(ptr);
144 __coverity_mark_as_afm_allocated__(ptr, "g_free");
145 return ptr;
146 }
147
148 void *g_realloc_n(void *ptr, size_t nmemb, size_t size)
149 {
150 size_t sz;
151
152 __coverity_negative_sink__(nmemb);
153 __coverity_negative_sink__(size);
154 sz = nmemb * size;
155 __coverity_escape__(ptr);
156 ptr = __coverity_alloc__(sz);
157 /*
158 * Memory beyond the old size isn't actually initialized. Can't
159 * model that. See Coverity's realloc() model
160 */
161 __coverity_writeall__(ptr);
162 __coverity_mark_as_afm_allocated__(ptr, "g_free");
163 return ptr;
164 }
165
166 void g_free(void *ptr)
167 {
168 __coverity_free__(ptr);
169 __coverity_mark_as_afm_freed__(ptr, "g_free");
170 }
171
172 /*
173 * Derive the g_try_FOO_n() from the g_FOO_n() by adding indeterminate
174 * out of memory conditions
175 */
176
177 void *g_try_malloc_n(size_t nmemb, size_t size)
178 {
179 int nomem;
180
181 if (nomem) {
182 return NULL;
183 }
184 return g_malloc_n(nmemb, size);
185 }
186
187 void *g_try_malloc0_n(size_t nmemb, size_t size)
188 {
189 int nomem;
190
191 if (nomem) {
192 return NULL;
193 }
194 return g_malloc0_n(nmemb, size);
195 }
196
197 void *g_try_realloc_n(void *ptr, size_t nmemb, size_t size)
198 {
199 int nomem;
200
201 if (nomem) {
202 return NULL;
203 }
204 return g_realloc_n(ptr, nmemb, size);
205 }
206
207 /* Trivially derive the g_FOO() from the g_FOO_n() */
208
209 void *g_malloc(size_t size)
210 {
211 return g_malloc_n(1, size);
212 }
213
214 void *g_malloc0(size_t size)
215 {
216 return g_malloc0_n(1, size);
217 }
218
219 void *g_realloc(void *ptr, size_t size)
220 {
221 return g_realloc_n(ptr, 1, size);
222 }
223
224 void *g_try_malloc(size_t size)
225 {
226 return g_try_malloc_n(1, size);
227 }
228
229 void *g_try_malloc0(size_t size)
230 {
231 return g_try_malloc0_n(1, size);
232 }
233
234 void *g_try_realloc(void *ptr, size_t size)
235 {
236 return g_try_realloc_n(ptr, 1, size);
237 }
238
239 /* Other memory allocation functions */
240
241 void *g_memdup(const void *ptr, unsigned size)
242 {
243 unsigned char *dup;
244 unsigned i;
245
246 if (!ptr) {
247 return NULL;
248 }
249
250 dup = g_malloc(size);
251 for (i = 0; i < size; i++)
252 dup[i] = ((unsigned char *)ptr)[i];
253 return dup;
254 }
255
256 /*
257 * GLib string allocation functions
258 */
259
260 char *g_strdup(const char *s)
261 {
262 char *dup;
263 size_t i;
264
265 if (!s) {
266 return NULL;
267 }
268
269 __coverity_string_null_sink__(s);
270 __coverity_string_size_sink__(s);
271 dup = __coverity_alloc_nosize__();
272 __coverity_mark_as_afm_allocated__(dup, "g_free");
273 for (i = 0; (dup[i] = s[i]); i++) ;
274 return dup;
275 }
276
277 char *g_strndup(const char *s, size_t n)
278 {
279 char *dup;
280 size_t i;
281
282 __coverity_negative_sink__(n);
283
284 if (!s) {
285 return NULL;
286 }
287
288 dup = g_malloc(n + 1);
289 for (i = 0; i < n && (dup[i] = s[i]); i++) ;
290 dup[i] = 0;
291 return dup;
292 }
293
294 char *g_strdup_printf(const char *format, ...)
295 {
296 char ch, *s;
297 size_t len;
298
299 __coverity_string_null_sink__(format);
300 __coverity_string_size_sink__(format);
301
302 ch = *format;
303
304 s = __coverity_alloc_nosize__();
305 __coverity_writeall__(s);
306 __coverity_mark_as_afm_allocated__(s, "g_free");
307 return s;
308 }
309
310 char *g_strdup_vprintf(const char *format, va_list ap)
311 {
312 char ch, *s;
313 size_t len;
314
315 __coverity_string_null_sink__(format);
316 __coverity_string_size_sink__(format);
317
318 ch = *format;
319 ch = *(char *)ap;
320
321 s = __coverity_alloc_nosize__();
322 __coverity_writeall__(s);
323 __coverity_mark_as_afm_allocated__(s, "g_free");
324
325 return len;
326 }
327
328 char *g_strconcat(const char *s, ...)
329 {
330 char *s;
331
332 /*
333 * Can't model: last argument must be null, the others
334 * null-terminated strings
335 */
336
337 s = __coverity_alloc_nosize__();
338 __coverity_writeall__(s);
339 __coverity_mark_as_afm_allocated__(s, "g_free");
340 return s;
341 }
342
343 /* Other glib functions */
344
345 typedef struct pollfd GPollFD;
346
347 int poll();
348
349 int g_poll (GPollFD *fds, unsigned nfds, int timeout)
350 {
351 return poll(fds, nfds, timeout);
352 }
353
354 typedef struct _GIOChannel GIOChannel;
355 GIOChannel *g_io_channel_unix_new(int fd)
356 {
357 GIOChannel *c = g_malloc0(sizeof(GIOChannel));
358 __coverity_escape__(fd);
359 return c;
360 }
361
362 void g_assertion_message_expr(const char *domain,
363 const char *file,
364 int line,
365 const char *func,
366 const char *expr)
367 {
368 __coverity_panic__();
369 }