+++ /dev/null
-/*
- * lib/dynamic_printk.c
- *
- * make pr_debug()/dev_dbg() calls runtime configurable based upon their
- * their source module.
- *
- * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/uaccess.h>
-#include <linux/seq_file.h>
-#include <linux/debugfs.h>
-#include <linux/fs.h>
-
-extern struct mod_debug __start___verbose[];
-extern struct mod_debug __stop___verbose[];
-
-struct debug_name {
- struct hlist_node hlist;
- struct hlist_node hlist2;
- int hash1;
- int hash2;
- char *name;
- int enable;
- int type;
-};
-
-static int nr_entries;
-static int num_enabled;
-int dynamic_enabled = DYNAMIC_ENABLED_NONE;
-static struct hlist_head module_table[DEBUG_HASH_TABLE_SIZE] =
- { [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT };
-static struct hlist_head module_table2[DEBUG_HASH_TABLE_SIZE] =
- { [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT };
-static DECLARE_MUTEX(debug_list_mutex);
-
-/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
- * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
- * use independent hash functions, to reduce the chance of false positives.
- */
-long long dynamic_printk_enabled;
-EXPORT_SYMBOL_GPL(dynamic_printk_enabled);
-long long dynamic_printk_enabled2;
-EXPORT_SYMBOL_GPL(dynamic_printk_enabled2);
-
-/* returns the debug module pointer. */
-static struct debug_name *find_debug_module(char *module_name)
-{
- int i;
- struct hlist_head *head;
- struct hlist_node *node;
- struct debug_name *element;
-
- element = NULL;
- for (i = 0; i < DEBUG_HASH_TABLE_SIZE; i++) {
- head = &module_table[i];
- hlist_for_each_entry_rcu(element, node, head, hlist)
- if (!strcmp(element->name, module_name))
- return element;
- }
- return NULL;
-}
-
-/* returns the debug module pointer. */
-static struct debug_name *find_debug_module_hash(char *module_name, int hash)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct debug_name *element;
-
- element = NULL;
- head = &module_table[hash];
- hlist_for_each_entry_rcu(element, node, head, hlist)
- if (!strcmp(element->name, module_name))
- return element;
- return NULL;
-}
-
-/* caller must hold mutex*/
-static int __add_debug_module(char *mod_name, int hash, int hash2)
-{
- struct debug_name *new;
- char *module_name;
- int ret = 0;
-
- if (find_debug_module(mod_name)) {
- ret = -EINVAL;
- goto out;
- }
- module_name = kmalloc(strlen(mod_name) + 1, GFP_KERNEL);
- if (!module_name) {
- ret = -ENOMEM;
- goto out;
- }
- module_name = strcpy(module_name, mod_name);
- module_name[strlen(mod_name)] = '\0';
- new = kzalloc(sizeof(struct debug_name), GFP_KERNEL);
- if (!new) {
- kfree(module_name);
- ret = -ENOMEM;
- goto out;
- }
- INIT_HLIST_NODE(&new->hlist);
- INIT_HLIST_NODE(&new->hlist2);
- new->name = module_name;
- new->hash1 = hash;
- new->hash2 = hash2;
- hlist_add_head_rcu(&new->hlist, &module_table[hash]);
- hlist_add_head_rcu(&new->hlist2, &module_table2[hash2]);
- nr_entries++;
-out:
- return ret;
-}
-
-int unregister_dynamic_debug_module(char *mod_name)
-{
- struct debug_name *element;
- int ret = 0;
-
- down(&debug_list_mutex);
- element = find_debug_module(mod_name);
- if (!element) {
- ret = -EINVAL;
- goto out;
- }
- hlist_del_rcu(&element->hlist);
- hlist_del_rcu(&element->hlist2);
- synchronize_rcu();
- kfree(element->name);
- if (element->enable)
- num_enabled--;
- kfree(element);
- nr_entries--;
-out:
- up(&debug_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(unregister_dynamic_debug_module);
-
-int register_dynamic_debug_module(char *mod_name, int type, char *share_name,
- char *flags, int hash, int hash2)
-{
- struct debug_name *elem;
- int ret = 0;
-
- down(&debug_list_mutex);
- elem = find_debug_module(mod_name);
- if (!elem) {
- if (__add_debug_module(mod_name, hash, hash2))
- goto out;
- elem = find_debug_module(mod_name);
- if (dynamic_enabled == DYNAMIC_ENABLED_ALL &&
- !strcmp(mod_name, share_name)) {
- elem->enable = true;
- num_enabled++;
- }
- }
- elem->type |= type;
-out:
- up(&debug_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(register_dynamic_debug_module);
-
-int __dynamic_dbg_enabled_helper(char *mod_name, int type, int value, int hash)
-{
- struct debug_name *elem;
- int ret = 0;
-
- if (dynamic_enabled == DYNAMIC_ENABLED_ALL)
- return 1;
- rcu_read_lock();
- elem = find_debug_module_hash(mod_name, hash);
- if (elem && elem->enable)
- ret = 1;
- rcu_read_unlock();
- return ret;
-}
-EXPORT_SYMBOL_GPL(__dynamic_dbg_enabled_helper);
-
-static void set_all(bool enable)
-{
- struct debug_name *e;
- struct hlist_node *node;
- int i;
- long long enable_mask;
-
- for (i = 0; i < DEBUG_HASH_TABLE_SIZE; i++) {
- if (module_table[i].first != NULL) {
- hlist_for_each_entry(e, node, &module_table[i], hlist) {
- e->enable = enable;
- }
- }
- }
- if (enable)
- enable_mask = ULLONG_MAX;
- else
- enable_mask = 0;
- dynamic_printk_enabled = enable_mask;
- dynamic_printk_enabled2 = enable_mask;
-}
-
-static int disabled_hash(int i, bool first_table)
-{
- struct debug_name *e;
- struct hlist_node *node;
-
- if (first_table) {
- hlist_for_each_entry(e, node, &module_table[i], hlist) {
- if (e->enable)
- return 0;
- }
- } else {
- hlist_for_each_entry(e, node, &module_table2[i], hlist2) {
- if (e->enable)
- return 0;
- }
- }
- return 1;
-}
-
-static ssize_t pr_debug_write(struct file *file, const char __user *buf,
- size_t length, loff_t *ppos)
-{
- char *buffer, *s, *value_str, *setting_str;
- int err, value;
- struct debug_name *elem = NULL;
- int all = 0;
-
- if (length > PAGE_SIZE || length < 0)
- return -EINVAL;
-
- buffer = (char *)__get_free_page(GFP_KERNEL);
- if (!buffer)
- return -ENOMEM;
-
- err = -EFAULT;
- if (copy_from_user(buffer, buf, length))
- goto out;
-
- err = -EINVAL;
- if (length < PAGE_SIZE)
- buffer[length] = '\0';
- else if (buffer[PAGE_SIZE-1])
- goto out;
-
- err = -EINVAL;
- down(&debug_list_mutex);
-
- if (strncmp("set", buffer, 3))
- goto out_up;
- s = buffer + 3;
- setting_str = strsep(&s, "=");
- if (s == NULL)
- goto out_up;
- setting_str = strstrip(setting_str);
- value_str = strsep(&s, " ");
- if (s == NULL)
- goto out_up;
- s = strstrip(s);
- if (!strncmp(s, "all", 3))
- all = 1;
- else
- elem = find_debug_module(s);
- if (!strncmp(setting_str, "enable", 6)) {
- value = !!simple_strtol(value_str, NULL, 10);
- if (all) {
- if (value) {
- set_all(true);
- num_enabled = nr_entries;
- dynamic_enabled = DYNAMIC_ENABLED_ALL;
- } else {
- set_all(false);
- num_enabled = 0;
- dynamic_enabled = DYNAMIC_ENABLED_NONE;
- }
- err = 0;
- } else if (elem) {
- if (value && (elem->enable == 0)) {
- dynamic_printk_enabled |= (1LL << elem->hash1);
- dynamic_printk_enabled2 |= (1LL << elem->hash2);
- elem->enable = 1;
- num_enabled++;
- dynamic_enabled = DYNAMIC_ENABLED_SOME;
- err = 0;
- printk(KERN_DEBUG
- "debugging enabled for module %s\n",
- elem->name);
- } else if (!value && (elem->enable == 1)) {
- elem->enable = 0;
- num_enabled--;
- if (disabled_hash(elem->hash1, true))
- dynamic_printk_enabled &=
- ~(1LL << elem->hash1);
- if (disabled_hash(elem->hash2, false))
- dynamic_printk_enabled2 &=
- ~(1LL << elem->hash2);
- if (num_enabled)
- dynamic_enabled = DYNAMIC_ENABLED_SOME;
- else
- dynamic_enabled = DYNAMIC_ENABLED_NONE;
- err = 0;
- printk(KERN_DEBUG
- "debugging disabled for module %s\n",
- elem->name);
- }
- }
- }
- if (!err)
- err = length;
-out_up:
- up(&debug_list_mutex);
-out:
- free_page((unsigned long)buffer);
- return err;
-}
-
-static void *pr_debug_seq_start(struct seq_file *f, loff_t *pos)
-{
- return (*pos < DEBUG_HASH_TABLE_SIZE) ? pos : NULL;
-}
-
-static void *pr_debug_seq_next(struct seq_file *s, void *v, loff_t *pos)
-{
- (*pos)++;
- if (*pos >= DEBUG_HASH_TABLE_SIZE)
- return NULL;
- return pos;
-}
-
-static void pr_debug_seq_stop(struct seq_file *s, void *v)
-{
- /* Nothing to do */
-}
-
-static int pr_debug_seq_show(struct seq_file *s, void *v)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct debug_name *elem;
- unsigned int i = *(loff_t *) v;
-
- rcu_read_lock();
- head = &module_table[i];
- hlist_for_each_entry_rcu(elem, node, head, hlist) {
- seq_printf(s, "%s enabled=%d", elem->name, elem->enable);
- seq_printf(s, "\n");
- }
- rcu_read_unlock();
- return 0;
-}
-
-static struct seq_operations pr_debug_seq_ops = {
- .start = pr_debug_seq_start,
- .next = pr_debug_seq_next,
- .stop = pr_debug_seq_stop,
- .show = pr_debug_seq_show
-};
-
-static int pr_debug_open(struct inode *inode, struct file *filp)
-{
- return seq_open(filp, &pr_debug_seq_ops);
-}
-
-static const struct file_operations pr_debug_operations = {
- .open = pr_debug_open,
- .read = seq_read,
- .write = pr_debug_write,
- .llseek = seq_lseek,
- .release = seq_release,
-};
-
-static int __init dynamic_printk_init(void)
-{
- struct dentry *dir, *file;
- struct mod_debug *iter;
- unsigned long value;
-
- dir = debugfs_create_dir("dynamic_printk", NULL);
- if (!dir)
- return -ENOMEM;
- file = debugfs_create_file("modules", 0644, dir, NULL,
- &pr_debug_operations);
- if (!file) {
- debugfs_remove(dir);
- return -ENOMEM;
- }
- for (value = (unsigned long)__start___verbose;
- value < (unsigned long)__stop___verbose;
- value += sizeof(struct mod_debug)) {
- iter = (struct mod_debug *)value;
- register_dynamic_debug_module(iter->modname,
- iter->type,
- iter->logical_modname,
- iter->flag_names, iter->hash, iter->hash2);
- }
- if (dynamic_enabled == DYNAMIC_ENABLED_ALL)
- set_all(true);
- return 0;
-}
-module_init(dynamic_printk_init);
-/* may want to move this earlier so we can get traces as early as possible */
-
-static int __init dynamic_printk_setup(char *str)
-{
- if (str)
- return -ENOENT;
- dynamic_enabled = DYNAMIC_ENABLED_ALL;
- return 0;
-}
-/* Use early_param(), so we can get debug output as early as possible */
-early_param("dynamic_printk", dynamic_printk_setup);
projects / linux-2.6-omap-h63xx.git / blobdiff