summaryrefslogtreecommitdiffstats
path: root/qemu/util/module.c
blob: 4bd4a94d87f290d374a456c28d9f802fc426c9bd (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
/*
 * 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 <stdlib.h>
#include "qemu-common.h"
#ifdef CONFIG_MODULES
#include <gmodule.h>
#endif
#include "qemu/queue.h"
#include "qemu/module.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 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)
{
    ModuleTypeList *l;

    init_lists();

    l = &init_type_list[type];

    return l;
}

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);
}

static void module_load(module_init_type type);

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

    module_load(type);
    l = find_type(type);

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

#ifdef CONFIG_MODULES
static int module_load_file(const char *fname)
{
    GModule *g_module;
    void (*sym)(void);
    const char *dsosuf = HOST_DSOSUF;
    int len = strlen(fname);
    int suf_len = strlen(dsosuf);
    ModuleEntry *e, *next;
    int ret;

    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));

    g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
    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) {
            register_module_init(e->init, e->type);
        }
        ret = 0;
    }

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

static void module_load(module_init_type type)
{
#ifdef CONFIG_MODULES
    char *fname = NULL;
    const char **mp;
    static const char *block_modules[] = {
        CONFIG_BLOCK_MODULES
    };
    char *exec_dir;
    char *dirs[3];
    int i = 0;
    int ret;

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

    switch (type) {
    case MODULE_INIT_BLOCK:
        mp = block_modules;
        break;
    default:
        /* no other types have dynamic modules for now*/
        return;
    }

    exec_dir = qemu_get_exec_dir();
    dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR);
    dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : "");
    dirs[i++] = g_strdup_printf("%s", exec_dir ? : "");
    assert(i == ARRAY_SIZE(dirs));
    g_free(exec_dir);
    exec_dir = NULL;

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

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

#endif
}