jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
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
34typedef unsigned char uint8_t;
35typedef char int8_t;
36typedef unsigned int uint32_t;
37typedef int int32_t;
38typedef long ssize_t;
39typedef unsigned long long uint64_t;
40typedef long long int64_t;
41typedef _Bool bool;
42
43typedef struct va_list_str *va_list;
44
45/* exec.c */
46
47typedef struct AddressSpace AddressSpace;
48typedef uint64_t hwaddr;
49typedef uint32_t MemTxResult;
50typedef uint64_t MemTxAttrs;
51
52static 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
62static 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
70MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
71 MemTxAttrs attrs,
72 uint8_t *buf, int len)
73{
74 MemTxResult result;
75 // TODO: investigate impact of treating reads as producing
76 // tainted data, with __coverity_tainted_data_argument__(buf).
77 __bufwrite(buf, len);
78 return result;
79}
80
81MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
82 MemTxAttrs attrs,
83 const uint8_t *buf, int len)
84{
85 MemTxResult result;
86 __bufread(buf, len);
87 return result;
88}
89
90
91/* Tainting */
92
93typedef struct {} name2keysym_t;
94static int get_keysym(const name2keysym_t *table,
95 const char *name)
96{
97 int result;
98 if (result > 0) {
99 __coverity_tainted_string_sanitize_content__(name);
100 return result;
101 } else {
102 return 0;
103 }
104}
105
106/* Replay data is considered trusted. */
107uint8_t replay_get_byte(void)
108{
109 uint8_t byte;
110 return byte;
111}
112
113
114/*
115 * GLib memory allocation functions.
116 *
117 * Note that we ignore the fact that g_malloc of 0 bytes returns NULL,
118 * and g_realloc of 0 bytes frees the pointer.
119 *
120 * Modeling this would result in Coverity flagging a lot of memory
121 * allocations as potentially returning NULL, and asking us to check
122 * whether the result of the allocation is NULL or not. However, the
123 * resulting pointer should never be dereferenced anyway, and in fact
124 * it is not in the vast majority of cases.
125 *
126 * If a dereference did happen, this would suppress a defect report
127 * for an actual null pointer dereference. But it's too unlikely to
128 * be worth wading through the false positives, and with some luck
129 * we'll get a buffer overflow reported anyway.
130 */
131
132/*
133 * Allocation primitives, cannot return NULL
134 * See also Coverity's library/generic/libc/all/all.c
135 */
136
137void *g_malloc_n(size_t nmemb, size_t size)
138{
139 size_t sz;
140 void *ptr;
141
142 __coverity_negative_sink__(nmemb);
143 __coverity_negative_sink__(size);
144 sz = nmemb * size;
145 ptr = __coverity_alloc__(sz);
146 __coverity_mark_as_uninitialized_buffer__(ptr);
147 __coverity_mark_as_afm_allocated__(ptr, "g_free");
148 return ptr;
149}
150
151void *g_malloc0_n(size_t nmemb, size_t size)
152{
153 size_t sz;
154 void *ptr;
155
156 __coverity_negative_sink__(nmemb);
157 __coverity_negative_sink__(size);
158 sz = nmemb * size;
159 ptr = __coverity_alloc__(sz);
160 __coverity_writeall0__(ptr);
161 __coverity_mark_as_afm_allocated__(ptr, "g_free");
162 return ptr;
163}
164
165void *g_realloc_n(void *ptr, size_t nmemb, size_t size)
166{
167 size_t sz;
168
169 __coverity_negative_sink__(nmemb);
170 __coverity_negative_sink__(size);
171 sz = nmemb * size;
172 __coverity_escape__(ptr);
173 ptr = __coverity_alloc__(sz);
174 /*
175 * Memory beyond the old size isn't actually initialized. Can't
176 * model that. See Coverity's realloc() model
177 */
178 __coverity_writeall__(ptr);
179 __coverity_mark_as_afm_allocated__(ptr, "g_free");
180 return ptr;
181}
182
183void g_free(void *ptr)
184{
185 __coverity_free__(ptr);
186 __coverity_mark_as_afm_freed__(ptr, "g_free");
187}
188
189/*
190 * Derive the g_try_FOO_n() from the g_FOO_n() by adding indeterminate
191 * out of memory conditions
192 */
193
194void *g_try_malloc_n(size_t nmemb, size_t size)
195{
196 int nomem;
197
198 if (nomem) {
199 return NULL;
200 }
201 return g_malloc_n(nmemb, size);
202}
203
204void *g_try_malloc0_n(size_t nmemb, size_t size)
205{
206 int nomem;
207
208 if (nomem) {
209 return NULL;
210 }
211 return g_malloc0_n(nmemb, size);
212}
213
214void *g_try_realloc_n(void *ptr, size_t nmemb, size_t size)
215{
216 int nomem;
217
218 if (nomem) {
219 return NULL;
220 }
221 return g_realloc_n(ptr, nmemb, size);
222}
223
224/* Trivially derive the g_FOO() from the g_FOO_n() */
225
226void *g_malloc(size_t size)
227{
228 return g_malloc_n(1, size);
229}
230
231void *g_malloc0(size_t size)
232{
233 return g_malloc0_n(1, size);
234}
235
236void *g_realloc(void *ptr, size_t size)
237{
238 return g_realloc_n(ptr, 1, size);
239}
240
241void *g_try_malloc(size_t size)
242{
243 return g_try_malloc_n(1, size);
244}
245
246void *g_try_malloc0(size_t size)
247{
248 return g_try_malloc0_n(1, size);
249}
250
251void *g_try_realloc(void *ptr, size_t size)
252{
253 return g_try_realloc_n(ptr, 1, size);
254}
255
256/* Other memory allocation functions */
257
258void *g_memdup(const void *ptr, unsigned size)
259{
260 unsigned char *dup;
261 unsigned i;
262
263 if (!ptr) {
264 return NULL;
265 }
266
267 dup = g_malloc(size);
268 for (i = 0; i < size; i++)
269 dup[i] = ((unsigned char *)ptr)[i];
270 return dup;
271}
272
273/*
274 * GLib string allocation functions
275 */
276
277char *g_strdup(const char *s)
278{
279 char *dup;
280 size_t i;
281
282 if (!s) {
283 return NULL;
284 }
285
286 __coverity_string_null_sink__(s);
287 __coverity_string_size_sink__(s);
288 dup = __coverity_alloc_nosize__();
289 __coverity_mark_as_afm_allocated__(dup, "g_free");
290 for (i = 0; (dup[i] = s[i]); i++) ;
291 return dup;
292}
293
294char *g_strndup(const char *s, size_t n)
295{
296 char *dup;
297 size_t i;
298
299 __coverity_negative_sink__(n);
300
301 if (!s) {
302 return NULL;
303 }
304
305 dup = g_malloc(n + 1);
306 for (i = 0; i < n && (dup[i] = s[i]); i++) ;
307 dup[i] = 0;
308 return dup;
309}
310
311char *g_strdup_printf(const char *format, ...)
312{
313 char ch, *s;
314 size_t len;
315
316 __coverity_string_null_sink__(format);
317 __coverity_string_size_sink__(format);
318
319 ch = *format;
320
321 s = __coverity_alloc_nosize__();
322 __coverity_writeall__(s);
323 __coverity_mark_as_afm_allocated__(s, "g_free");
324 return s;
325}
326
327char *g_strdup_vprintf(const char *format, va_list ap)
328{
329 char ch, *s;
330 size_t len;
331
332 __coverity_string_null_sink__(format);
333 __coverity_string_size_sink__(format);
334
335 ch = *format;
336 ch = *(char *)ap;
337
338 s = __coverity_alloc_nosize__();
339 __coverity_writeall__(s);
340 __coverity_mark_as_afm_allocated__(s, "g_free");
341
342 return len;
343}
344
345char *g_strconcat(const char *s, ...)
346{
347 char *s;
348
349 /*
350 * Can't model: last argument must be null, the others
351 * null-terminated strings
352 */
353
354 s = __coverity_alloc_nosize__();
355 __coverity_writeall__(s);
356 __coverity_mark_as_afm_allocated__(s, "g_free");
357 return s;
358}
359
360/* Other glib functions */
361
362typedef struct pollfd GPollFD;
363
364int poll();
365
366int g_poll (GPollFD *fds, unsigned nfds, int timeout)
367{
368 return poll(fds, nfds, timeout);
369}
370
371typedef struct _GIOChannel GIOChannel;
372GIOChannel *g_io_channel_unix_new(int fd)
373{
374 GIOChannel *c = g_malloc0(sizeof(GIOChannel));
375 __coverity_escape__(fd);
376 return c;
377}
378
379void g_assertion_message_expr(const char *domain,
380 const char *file,
381 int line,
382 const char *func,
383 const char *expr)
384{
385 __coverity_panic__();
386}