| 1 | #include <linux/module.h>
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| 2 |
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| 3 | #include "notifier-error-inject.h"
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| 4 |
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| 5 | static int debugfs_errno_set(void *data, u64 val)
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| 6 | {
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| 7 | *(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
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| 8 | return 0;
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| 9 | }
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| 10 |
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| 11 | static int debugfs_errno_get(void *data, u64 *val)
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| 12 | {
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| 13 | *val = *(int *)data;
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| 14 | return 0;
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| 15 | }
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| 16 |
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| 17 | DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
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| 18 | "%lld\n");
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| 19 |
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| 20 | static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
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| 21 | struct dentry *parent, int *value)
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| 22 | {
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| 23 | return debugfs_create_file(name, mode, parent, value, &fops_errno);
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| 24 | }
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| 25 |
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| 26 | static int notifier_err_inject_callback(struct notifier_block *nb,
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| 27 | unsigned long val, void *p)
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| 28 | {
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| 29 | int err = 0;
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| 30 | struct notifier_err_inject *err_inject =
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| 31 | container_of(nb, struct notifier_err_inject, nb);
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| 32 | struct notifier_err_inject_action *action;
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| 33 |
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| 34 | for (action = err_inject->actions; action->name; action++) {
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| 35 | if (action->val == val) {
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| 36 | err = action->error;
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| 37 | break;
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| 38 | }
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| 39 | }
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| 40 | if (err)
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| 41 | pr_info("Injecting error (%d) to %s\n", err, action->name);
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| 42 |
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| 43 | return notifier_from_errno(err);
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| 44 | }
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| 45 |
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| 46 | struct dentry *notifier_err_inject_dir;
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| 47 | EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
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| 48 |
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| 49 | struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
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| 50 | struct notifier_err_inject *err_inject, int priority)
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| 51 | {
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| 52 | struct notifier_err_inject_action *action;
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| 53 | umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
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| 54 | struct dentry *dir;
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| 55 | struct dentry *actions_dir;
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| 56 |
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| 57 | err_inject->nb.notifier_call = notifier_err_inject_callback;
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| 58 | err_inject->nb.priority = priority;
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| 59 |
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| 60 | dir = debugfs_create_dir(name, parent);
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| 61 | if (!dir)
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| 62 | return ERR_PTR(-ENOMEM);
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| 63 |
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| 64 | actions_dir = debugfs_create_dir("actions", dir);
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| 65 | if (!actions_dir)
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| 66 | goto fail;
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| 67 |
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| 68 | for (action = err_inject->actions; action->name; action++) {
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| 69 | struct dentry *action_dir;
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| 70 |
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| 71 | action_dir = debugfs_create_dir(action->name, actions_dir);
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| 72 | if (!action_dir)
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| 73 | goto fail;
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| 74 |
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| 75 | |
| 76 | * Create debugfs r/w file containing action->error. If
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| 77 | * notifier call chain is called with action->val, it will
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| 78 | * fail with the error code
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| 79 |
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| 80 | if (!debugfs_create_errno("error", mode, action_dir,
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| 81 | &action->error))
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| 82 | goto fail;
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| 83 | }
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| 84 | return dir;
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| 85 | fail:
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| 86 | debugfs_remove_recursive(dir);
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| 87 | return ERR_PTR(-ENOMEM);
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| 88 | }
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| 89 | EXPORT_SYMBOL_GPL(notifier_err_inject_init);
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| 90 |
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| 91 | static int __init err_inject_init(void)
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| 92 | {
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| 93 | notifier_err_inject_dir =
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| 94 | debugfs_create_dir("notifier-error-inject", NULL);
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| 95 |
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| 96 | if (!notifier_err_inject_dir)
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| 97 | return -ENOMEM;
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| 98 |
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| 99 | return 0;
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| 100 | }
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| 101 |
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| 102 | static void __exit err_inject_exit(void)
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| 103 | {
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| 104 | debugfs_remove_recursive(notifier_err_inject_dir);
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| 105 | }
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| 106 |
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| 107 | module_init(err_inject_init);
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| 108 | module_exit(err_inject_exit);
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| 109 |
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| 110 | MODULE_DESCRIPTION("Notifier error injection module");
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| 111 | MODULE_LICENSE("GPL");
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| 112 | MODULE_AUTHOR("Akinobu Mita <[email protected]>");
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