diff options
Diffstat (limited to 'lib/dynamic_printk.c')
| -rw-r--r-- | lib/dynamic_printk.c | 414 |
1 files changed, 0 insertions, 414 deletions
diff --git a/lib/dynamic_printk.c b/lib/dynamic_printk.c deleted file mode 100644 index 165a197..0000000 --- a/lib/dynamic_printk.c +++ /dev/null @@ -1,414 +0,0 @@ -/* - * 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); |