aboutsummaryrefslogtreecommitdiff
path: root/util/module.c
blob: ad89cd50dc2a03ea6f8431849137b54784e1498e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
/*
 * QEMU Module Infrastructure
 *
 * Copyright IBM, Corp. 2009
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 * Contributions after 2012-01-13 are licensed under the terms of the
 * GNU GPL, version 2 or (at your option) any later version.
 */

#include "qemu/osdep.h"
#ifdef CONFIG_MODULES
#include <gmodule.h>
#endif
#include "qemu/queue.h"
#include "qemu/module.h"
#include "qemu/cutils.h"
#include "qemu/config-file.h"
#ifdef CONFIG_MODULE_UPGRADES
#include "qemu-version.h"
#endif
#include "trace.h"

typedef struct ModuleEntry
{
    void (*init)(void);
    QTAILQ_ENTRY(ModuleEntry) node;
    module_init_type type;
} ModuleEntry;

typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;

static ModuleTypeList init_type_list[MODULE_INIT_MAX];
static bool modules_init_done[MODULE_INIT_MAX];

static ModuleTypeList dso_init_list;

static void init_lists(void)
{
    static int inited;
    int i;

    if (inited) {
        return;
    }

    for (i = 0; i < MODULE_INIT_MAX; i++) {
        QTAILQ_INIT(&init_type_list[i]);
    }

    QTAILQ_INIT(&dso_init_list);

    inited = 1;
}


static ModuleTypeList *find_type(module_init_type type)
{
    init_lists();

    return &init_type_list[type];
}

void register_module_init(void (*fn)(void), module_init_type type)
{
    ModuleEntry *e;
    ModuleTypeList *l;

    e = g_malloc0(sizeof(*e));
    e->init = fn;
    e->type = type;

    l = find_type(type);

    QTAILQ_INSERT_TAIL(l, e, node);
}

void register_dso_module_init(void (*fn)(void), module_init_type type)
{
    ModuleEntry *e;

    init_lists();

    e = g_malloc0(sizeof(*e));
    e->init = fn;
    e->type = type;

    QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
}

void module_call_init(module_init_type type)
{
    ModuleTypeList *l;
    ModuleEntry *e;

    if (modules_init_done[type]) {
        return;
    }

    l = find_type(type);

    QTAILQ_FOREACH(e, l, node) {
        e->init();
    }

    modules_init_done[type] = true;
}

#ifdef CONFIG_MODULES

static const QemuModinfo module_info_stub[] = { {
    /* end of list */
} };
static const QemuModinfo *module_info = module_info_stub;
static const char *module_arch;

void module_init_info(const QemuModinfo *info)
{
    module_info = info;
}

void module_allow_arch(const char *arch)
{
    module_arch = arch;
}

static bool module_check_arch(const QemuModinfo *modinfo)
{
    if (modinfo->arch) {
        if (!module_arch) {
            /* no arch set -> ignore all */
            return false;
        }
        if (strcmp(module_arch, modinfo->arch) != 0) {
            /* mismatch */
            return false;
        }
    }
    return true;
}

static int module_load_file(const char *fname, bool export_symbols)
{
    GModule *g_module;
    void (*sym)(void);
    const char *dsosuf = CONFIG_HOST_DSOSUF;
    int len = strlen(fname);
    int suf_len = strlen(dsosuf);
    ModuleEntry *e, *next;
    int ret, flags;

    if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
        /* wrong suffix */
        ret = -EINVAL;
        goto out;
    }
    if (access(fname, F_OK)) {
        ret = -ENOENT;
        goto out;
    }

    assert(QTAILQ_EMPTY(&dso_init_list));

    flags = 0;
    if (!export_symbols) {
        flags |= G_MODULE_BIND_LOCAL;
    }
    g_module = g_module_open(fname, flags);
    if (!g_module) {
        fprintf(stderr, "Failed to open module: %s\n",
                g_module_error());
        ret = -EINVAL;
        goto out;
    }
    if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
        fprintf(stderr, "Failed to initialize module: %s\n",
                fname);
        /* Print some info if this is a QEMU module (but from different build),
         * this will make debugging user problems easier. */
        if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) {
            fprintf(stderr,
                    "Note: only modules from the same build can be loaded.\n");
        }
        g_module_close(g_module);
        ret = -EINVAL;
    } else {
        QTAILQ_FOREACH(e, &dso_init_list, node) {
            e->init();
            register_module_init(e->init, e->type);
        }
        ret = 0;
    }

    trace_module_load_module(fname);
    QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
        QTAILQ_REMOVE(&dso_init_list, e, node);
        g_free(e);
    }
out:
    return ret;
}
#endif

bool module_load(const char *prefix, const char *lib_name)
{
    bool success = false;

#ifdef CONFIG_MODULES
    char *fname = NULL;
#ifdef CONFIG_MODULE_UPGRADES
    char *version_dir;
#endif
    const char *search_dir;
    char *dirs[5];
    char *module_name;
    int i = 0, n_dirs = 0;
    int ret;
    bool export_symbols = false;
    static GHashTable *loaded_modules;
    const QemuModinfo *modinfo;
    const char **sl;

    if (!g_module_supported()) {
        fprintf(stderr, "Module is not supported by system.\n");
        return false;
    }

    if (!loaded_modules) {
        loaded_modules = g_hash_table_new(g_str_hash, g_str_equal);
    }

    module_name = g_strdup_printf("%s%s", prefix, lib_name);

    if (g_hash_table_contains(loaded_modules, module_name)) {
        g_free(module_name);
        return true;
    }
    g_hash_table_add(loaded_modules, module_name);

    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
        if (modinfo->arch) {
            if (strcmp(modinfo->name, module_name) == 0) {
                if (!module_check_arch(modinfo)) {
                    return false;
                }
            }
        }
        if (modinfo->deps) {
            if (strcmp(modinfo->name, module_name) == 0) {
                /* we depend on other module(s) */
                for (sl = modinfo->deps; *sl != NULL; sl++) {
                    module_load("", *sl);
                }
            } else {
                for (sl = modinfo->deps; *sl != NULL; sl++) {
                    if (strcmp(module_name, *sl) == 0) {
                        /* another module depends on us */
                        export_symbols = true;
                    }
                }
            }
        }
    }

    search_dir = getenv("QEMU_MODULE_DIR");
    if (search_dir != NULL) {
        dirs[n_dirs++] = g_strdup_printf("%s", search_dir);
    }
    dirs[n_dirs++] = get_relocated_path(CONFIG_QEMU_MODDIR);

#ifdef CONFIG_MODULE_UPGRADES
    version_dir = g_strcanon(g_strdup(QEMU_PKGVERSION),
                             G_CSET_A_2_Z G_CSET_a_2_z G_CSET_DIGITS "+-.~",
                             '_');
    dirs[n_dirs++] = g_strdup_printf("/var/run/qemu/%s", version_dir);
#endif

    assert(n_dirs <= ARRAY_SIZE(dirs));

    for (i = 0; i < n_dirs; i++) {
        fname = g_strdup_printf("%s/%s%s",
                dirs[i], module_name, CONFIG_HOST_DSOSUF);
        ret = module_load_file(fname, export_symbols);
        g_free(fname);
        fname = NULL;
        /* Try loading until loaded a module file */
        if (!ret) {
            success = true;
            break;
        }
    }

    if (!success) {
        g_hash_table_remove(loaded_modules, module_name);
        g_free(module_name);
    }

    for (i = 0; i < n_dirs; i++) {
        g_free(dirs[i]);
    }

#endif
    return success;
}

#ifdef CONFIG_MODULES

static bool module_loaded_qom_all;

void module_load_qom(const char *type)
{
    const QemuModinfo *modinfo;
    const char **sl;

    if (!type) {
        return;
    }

    trace_module_lookup_object_type(type);
    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
        if (!modinfo->objs) {
            continue;
        }
        if (!module_check_arch(modinfo)) {
            continue;
        }
        for (sl = modinfo->objs; *sl != NULL; sl++) {
            if (strcmp(type, *sl) == 0) {
                module_load("", modinfo->name);
            }
        }
    }
}

void module_load_qom_all(void)
{
    const QemuModinfo *modinfo;

    if (module_loaded_qom_all) {
        return;
    }

    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
        if (!modinfo->objs) {
            continue;
        }
        if (!module_check_arch(modinfo)) {
            continue;
        }
        module_load("", modinfo->name);
    }
    module_loaded_qom_all = true;
}

void qemu_load_module_for_opts(const char *group)
{
    const QemuModinfo *modinfo;
    const char **sl;

    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
        if (!modinfo->opts) {
            continue;
        }
        for (sl = modinfo->opts; *sl != NULL; sl++) {
            if (strcmp(group, *sl) == 0) {
                module_load("", modinfo->name);
            }
        }
    }
}

#else

void module_allow_arch(const char *arch) {}
void qemu_load_module_for_opts(const char *group) {}
void module_load_qom(const char *type) {}
void module_load_qom_all(void) {}

#endif