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