qemu/util/module.c
Andreas Färber bb2eb1892d module: Don't complain when a module is absent
The current implementation depends on a configure-time generated list of
block modules. When any of them is absent, module_load() emits a warning.

This is suboptimal because extracting code to modules was mainly done to
allow separate packaging of modules with intrusive dependencies. Absence
of optional packages then leads to absence of modules and an error
message, which users may recognize as new and report as error.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-18 14:57:35 +02:00

220 lines
4.8 KiB
C

/*
* 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
}