Re: [PATCH v2] fault-inject: support systematic fault injection

[Andrew Morton]

On Tue, 28 Mar 2017 15:01:28 +0200 Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:

> +static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
> +				   size_t count, loff_t *ppos)
> +{
> +	struct task_struct *task;
> +	int err, n;
> +
> +	task = get_proc_task(file_inode(file));
> +	if (!task)
> +		return -ESRCH;
> +	put_task_struct(task);
> +	if (task != current)
> +		return -EPERM;
> +	err = kstrtoint_from_user(buf, count, 10, &n);
> +	if (err)
> +		return err;
> +	if (n < 0 || n == INT_MAX)
> +		return -EINVAL;
> +	current->fail_nth = n + 1;
> +	return len;
> +}

Well that didn't go too well.

--- a/fs/proc/base.c~fault-inject-support-systematic-fault-injection-fix
+++ a/fs/proc/base.c
@@ -1377,7 +1377,7 @@ static ssize_t proc_fail_nth_write(struc
 	if (n < 0 || n == INT_MAX)
 		return -EINVAL;
 	current->fail_nth = n + 1;
-	return len;
+	return count;
 }
 
 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,

Are you sure I merged the correct version of this?