1 /* 2 * QEMU Module Infrastructure 3 * 4 * Copyright IBM, Corp. 2009 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 * Contributions after 2012-01-13 are licensed under the terms of the 13 * GNU GPL, version 2 or (at your option) any later version. 14 */ 15 16 #include "qemu/osdep.h" 17 #include "qemu-common.h" 18 #ifdef CONFIG_MODULES 19 #include <gmodule.h> 20 #endif 21 #include "qemu/queue.h" 22 #include "qemu/module.h" 23 24 typedef struct ModuleEntry 25 { 26 void (*init)(void); 27 QTAILQ_ENTRY(ModuleEntry) node; 28 module_init_type type; 29 } ModuleEntry; 30 31 typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList; 32 33 static ModuleTypeList init_type_list[MODULE_INIT_MAX]; 34 35 static ModuleTypeList dso_init_list; 36 37 static void init_lists(void) 38 { 39 static int inited; 40 int i; 41 42 if (inited) { 43 return; 44 } 45 46 for (i = 0; i < MODULE_INIT_MAX; i++) { 47 QTAILQ_INIT(&init_type_list[i]); 48 } 49 50 QTAILQ_INIT(&dso_init_list); 51 52 inited = 1; 53 } 54 55 56 static ModuleTypeList *find_type(module_init_type type) 57 { 58 init_lists(); 59 60 return &init_type_list[type]; 61 } 62 63 void register_module_init(void (*fn)(void), module_init_type type) 64 { 65 ModuleEntry *e; 66 ModuleTypeList *l; 67 68 e = g_malloc0(sizeof(*e)); 69 e->init = fn; 70 e->type = type; 71 72 l = find_type(type); 73 74 QTAILQ_INSERT_TAIL(l, e, node); 75 } 76 77 void register_dso_module_init(void (*fn)(void), module_init_type type) 78 { 79 ModuleEntry *e; 80 81 init_lists(); 82 83 e = g_malloc0(sizeof(*e)); 84 e->init = fn; 85 e->type = type; 86 87 QTAILQ_INSERT_TAIL(&dso_init_list, e, node); 88 } 89 90 void module_call_init(module_init_type type) 91 { 92 ModuleTypeList *l; 93 ModuleEntry *e; 94 95 l = find_type(type); 96 97 QTAILQ_FOREACH(e, l, node) { 98 e->init(); 99 } 100 } 101 102 #ifdef CONFIG_MODULES 103 static int module_load_file(const char *fname) 104 { 105 GModule *g_module; 106 void (*sym)(void); 107 const char *dsosuf = HOST_DSOSUF; 108 int len = strlen(fname); 109 int suf_len = strlen(dsosuf); 110 ModuleEntry *e, *next; 111 int ret; 112 113 if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) { 114 /* wrong suffix */ 115 ret = -EINVAL; 116 goto out; 117 } 118 if (access(fname, F_OK)) { 119 ret = -ENOENT; 120 goto out; 121 } 122 123 assert(QTAILQ_EMPTY(&dso_init_list)); 124 125 g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL); 126 if (!g_module) { 127 fprintf(stderr, "Failed to open module: %s\n", 128 g_module_error()); 129 ret = -EINVAL; 130 goto out; 131 } 132 if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) { 133 fprintf(stderr, "Failed to initialize module: %s\n", 134 fname); 135 /* Print some info if this is a QEMU module (but from different build), 136 * this will make debugging user problems easier. */ 137 if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) { 138 fprintf(stderr, 139 "Note: only modules from the same build can be loaded.\n"); 140 } 141 g_module_close(g_module); 142 ret = -EINVAL; 143 } else { 144 QTAILQ_FOREACH(e, &dso_init_list, node) { 145 e->init(); 146 register_module_init(e->init, e->type); 147 } 148 ret = 0; 149 } 150 151 QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) { 152 QTAILQ_REMOVE(&dso_init_list, e, node); 153 g_free(e); 154 } 155 out: 156 return ret; 157 } 158 #endif 159 160 void module_load_one(const char *prefix, const char *lib_name) 161 { 162 #ifdef CONFIG_MODULES 163 char *fname = NULL; 164 char *exec_dir; 165 char *dirs[3]; 166 int i = 0; 167 int ret; 168 169 if (!g_module_supported()) { 170 fprintf(stderr, "Module is not supported by system.\n"); 171 return; 172 } 173 174 exec_dir = qemu_get_exec_dir(); 175 dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR); 176 dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : ""); 177 dirs[i++] = g_strdup_printf("%s", exec_dir ? : ""); 178 assert(i == ARRAY_SIZE(dirs)); 179 g_free(exec_dir); 180 exec_dir = NULL; 181 182 for (i = 0; i < ARRAY_SIZE(dirs); i++) { 183 fname = g_strdup_printf("%s/%s%s%s", 184 dirs[i], prefix, lib_name, HOST_DSOSUF); 185 ret = module_load_file(fname); 186 g_free(fname); 187 fname = NULL; 188 /* Try loading until loaded a module file */ 189 if (!ret) { 190 break; 191 } 192 } 193 194 for (i = 0; i < ARRAY_SIZE(dirs); i++) { 195 g_free(dirs[i]); 196 } 197 198 #endif 199 } 200