+/**
+ * smk_read_ptrace - read() for /smack/ptrace
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @count: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t smk_read_ptrace(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char temp[32];
+ ssize_t rc;
+
+ if (*ppos != 0)
+ return 0;
+
+ sprintf(temp, "%d\n", smack_ptrace_rule);
+ rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
+ return rc;
+}
+
+/**
+ * smk_write_ptrace - write() for /smack/ptrace
+ * @file: file pointer
+ * @buf: data from user space
+ * @count: bytes sent
+ * @ppos: where to start - must be 0
+ */
+static ssize_t smk_write_ptrace(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char temp[32];
+ int i;
+
+ if (!smack_privileged(CAP_MAC_ADMIN))
+ return -EPERM;
+
+ if (*ppos != 0 || count >= sizeof(temp) || count == 0)
+ return -EINVAL;
+
+ if (copy_from_user(temp, buf, count) != 0)
+ return -EFAULT;
+
+ temp[count] = '\0';
+
+ if (sscanf(temp, "%d", &i) != 1)
+ return -EINVAL;
+ if (i < SMACK_PTRACE_DEFAULT || i > SMACK_PTRACE_MAX)
+ return -EINVAL;
+ smack_ptrace_rule = i;
+
+ return count;
+}
+
+static const struct file_operations smk_ptrace_ops = {
+ .write = smk_write_ptrace,
+ .read = smk_read_ptrace,
+ .llseek = default_llseek,
+};
+