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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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56f3364aba
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20190612153613.GA21239@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/module.h>
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#include "notifier-error-inject.h"
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static int debugfs_errno_set(void *data, u64 val)
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{
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*(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
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return 0;
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}
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static int debugfs_errno_get(void *data, u64 *val)
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{
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*val = *(int *)data;
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return 0;
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}
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DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
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"%lld\n");
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static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
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struct dentry *parent, int *value)
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{
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return debugfs_create_file(name, mode, parent, value, &fops_errno);
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}
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static int notifier_err_inject_callback(struct notifier_block *nb,
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unsigned long val, void *p)
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{
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int err = 0;
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struct notifier_err_inject *err_inject =
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container_of(nb, struct notifier_err_inject, nb);
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struct notifier_err_inject_action *action;
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for (action = err_inject->actions; action->name; action++) {
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if (action->val == val) {
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err = action->error;
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break;
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}
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}
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if (err)
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pr_info("Injecting error (%d) to %s\n", err, action->name);
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return notifier_from_errno(err);
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}
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struct dentry *notifier_err_inject_dir;
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EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
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struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
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struct notifier_err_inject *err_inject, int priority)
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{
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struct notifier_err_inject_action *action;
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umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
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struct dentry *dir;
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struct dentry *actions_dir;
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err_inject->nb.notifier_call = notifier_err_inject_callback;
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err_inject->nb.priority = priority;
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dir = debugfs_create_dir(name, parent);
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actions_dir = debugfs_create_dir("actions", dir);
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for (action = err_inject->actions; action->name; action++) {
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struct dentry *action_dir;
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action_dir = debugfs_create_dir(action->name, actions_dir);
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/*
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* Create debugfs r/w file containing action->error. If
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* notifier call chain is called with action->val, it will
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* fail with the error code
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*/
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debugfs_create_errno("error", mode, action_dir, &action->error);
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}
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return dir;
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}
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EXPORT_SYMBOL_GPL(notifier_err_inject_init);
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static int __init err_inject_init(void)
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{
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notifier_err_inject_dir =
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debugfs_create_dir("notifier-error-inject", NULL);
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if (!notifier_err_inject_dir)
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return -ENOMEM;
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return 0;
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}
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static void __exit err_inject_exit(void)
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{
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debugfs_remove_recursive(notifier_err_inject_dir);
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}
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module_init(err_inject_init);
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module_exit(err_inject_exit);
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MODULE_DESCRIPTION("Notifier error injection module");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
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