#include <linux/moduleloader.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
+#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
+#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/unwind.h>
+#include <linux/rculist.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <linux/license.h>
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
/* List of modules, protected by module_mutex or preempt_disable
- * (add/delete uses stop_machine). */
+ * (delete uses stop_machine/add uses RCU list operations). */
static DEFINE_MUTEX(module_mutex);
static LIST_HEAD(modules);
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
return true;
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
struct symsearch arr[] = {
{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
NOT_GPL_ONLY, false },
mod_sysfs_fini(mod);
}
-/*
- * link the module with the whole machine is stopped with interrupts off
- * - this defends against kallsyms not taking locks
- */
-static int __link_module(void *_mod)
-{
- struct module *mod = _mod;
- list_add(&mod->list, &modules);
- return 0;
-}
-
/*
* unlink the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
mod->name);
/* Now sew it into the lists so we can get lockdep and oops
- * info during argument parsing. Noone should access us, since
- * strong_try_module_get() will fail. */
- stop_machine(__link_module, mod, NULL);
+ * info during argument parsing. Noone should access us, since
+ * strong_try_module_get() will fail.
+ * lockdep/oops can run asynchronous, so use the RCU list insertion
+ * function to insert in a way safe to concurrent readers.
+ * The mutex protects against concurrent writers.
+ */
+ list_add_rcu(&mod->list, &modules);
err = parse_args(mod->name, mod->args, kp, num_kp, NULL);
if (err < 0)
const char *ret = NULL;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size)
|| within(addr, mod->module_core, mod->core_size)) {
if (modname)
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
const char *sym;
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
const char *sym;
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
*type = mod->symtab[symnum].st_info;
ret = mod_find_symname(mod, colon+1);
*colon = ':';
} else {
- list_for_each_entry(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list)
if ((ret = mod_find_symname(mod, name)) != 0)
break;
}
}
#endif /* CONFIG_KALLSYMS */
-/* Called by the /proc file system to return a list of modules. */
-static void *m_start(struct seq_file *m, loff_t *pos)
-{
- mutex_lock(&module_mutex);
- return seq_list_start(&modules, *pos);
-}
-
-static void *m_next(struct seq_file *m, void *p, loff_t *pos)
-{
- return seq_list_next(p, &modules, pos);
-}
-
-static void m_stop(struct seq_file *m, void *p)
-{
- mutex_unlock(&module_mutex);
-}
-
static char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
return buf;
}
+#ifdef CONFIG_PROC_FS
+/* Called by the /proc file system to return a list of modules. */
+static void *m_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&module_mutex);
+ return seq_list_start(&modules, *pos);
+}
+
+static void *m_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &modules, pos);
+}
+
+static void m_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&module_mutex);
+}
+
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
Where refcount is a number or -, and deps is a comma-separated list
of depends or -.
*/
-const struct seq_operations modules_op = {
+static const struct seq_operations modules_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = m_show
};
+static int modules_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &modules_op);
+}
+
+static const struct file_operations proc_modules_operations = {
+ .open = modules_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init proc_modules_init(void)
+{
+ proc_create("modules", 0, NULL, &proc_modules_operations);
+ return 0;
+}
+module_init(proc_modules_init);
+#endif
+
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (mod->num_exentries == 0)
continue;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_core, mod->core_size)) {
preempt_enable();
return 1;
if (addr < module_addr_min || addr > module_addr_max)
return NULL;
- list_for_each_entry(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list)
if (within(addr, mod->module_init, mod->init_text_size)
|| within(addr, mod->module_core, mod->core_text_size))
return mod;
char buf[8];
printk("Modules linked in:");
- list_for_each_entry(mod, &modules, list)
+ /* Most callers should already have preempt disabled, but make sure */
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list)
printk(" %s%s", mod->name, module_flags(mod, buf));
+ preempt_enable();
if (last_unloaded_module[0])
printk(" [last unloaded: %s]", last_unloaded_module);
printk("\n");