From: Arve Hjønnevåg <arve@android.com>
Date: Fri, 16 Jan 2009 03:07:27 +0000 (-0800)
Subject: Revert "printk: remove unused code from kernel/printk.c"
X-Git-Tag: firefly_0821_release~11681
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=afa82e25d4d6ab6500828cd7cc9d395a9c1e5d69;p=firefly-linux-kernel-4.4.55.git

Revert "printk: remove unused code from kernel/printk.c"

This reverts commit acff181d3574244e651913df77332e897b88bff4.
---

diff --git a/kernel/printk.c b/kernel/printk.c
index 0221437f1eab..448fdc68c8df 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -260,6 +260,45 @@ static inline void boot_delay_msec(void)
 }
 #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;
+}
+
 /*
  * Commands to do_syslog:
  *