Revert "printk: remove unused code from kernel/printk.c"
This reverts commit acff181d3574244e651913df77332e897b88bff4.
diff --git a/kernel/printk.c b/kernel/printk.c
index c451533..c78ed88 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -294,6 +294,45 @@
}
#endif
+/*
+ * Return the number of unread characters in the log buffer.
+ */
+static int log_buf_get_len(void)
+{
+ return logged_chars;
+}
+
+/*
+ * Copy a range of characters from the log buffer.
+ */
+int log_buf_copy(char *dest, int idx, int len)
+{
+ int ret, max;
+ bool took_lock = false;
+
+ if (!oops_in_progress) {
+ spin_lock_irq(&logbuf_lock);
+ took_lock = true;
+ }
+
+ max = log_buf_get_len();
+ if (idx < 0 || idx >= max) {
+ ret = -1;
+ } else {
+ if (len > max)
+ len = max;
+ ret = len;
+ idx += (log_end - max);
+ while (len-- > 0)
+ dest[len] = LOG_BUF(idx + len);
+ }
+
+ if (took_lock)
+ spin_unlock_irq(&logbuf_lock);
+
+ return ret;
+}
+
#ifdef CONFIG_SECURITY_DMESG_RESTRICT
int dmesg_restrict = 1;
#else