Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) #include "notifier-error-inject.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) static int debugfs_errno_set(void *data, u64 val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 	*(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) static int debugfs_errno_get(void *data, u64 *val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 	*val = *(int *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 			"%lld\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 				struct dentry *parent, int *value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	return debugfs_create_file(name, mode, parent, value, &fops_errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) static int notifier_err_inject_callback(struct notifier_block *nb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 				unsigned long val, void *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	struct notifier_err_inject *err_inject =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 		container_of(nb, struct notifier_err_inject, nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	struct notifier_err_inject_action *action;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	for (action = err_inject->actions; action->name; action++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 		if (action->val == val) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 			err = action->error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		pr_info("Injecting error (%d) to %s\n", err, action->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	return notifier_from_errno(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) struct dentry *notifier_err_inject_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			struct notifier_err_inject *err_inject, int priority)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	struct notifier_err_inject_action *action;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	struct dentry *dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	struct dentry *actions_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	err_inject->nb.notifier_call = notifier_err_inject_callback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	err_inject->nb.priority = priority;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	dir = debugfs_create_dir(name, parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	actions_dir = debugfs_create_dir("actions", dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	for (action = err_inject->actions; action->name; action++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		struct dentry *action_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		action_dir = debugfs_create_dir(action->name, actions_dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		 * Create debugfs r/w file containing action->error. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 		 * notifier call chain is called with action->val, it will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		 * fail with the error code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		debugfs_create_errno("error", mode, action_dir, &action->error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	return dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) EXPORT_SYMBOL_GPL(notifier_err_inject_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) static int __init err_inject_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	notifier_err_inject_dir =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		debugfs_create_dir("notifier-error-inject", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	if (!notifier_err_inject_dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) static void __exit err_inject_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	debugfs_remove_recursive(notifier_err_inject_dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) module_init(err_inject_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) module_exit(err_inject_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) MODULE_DESCRIPTION("Notifier error injection module");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");