Add banner_len to store banner length.
This is useful to save the banner into dumping mechanisms.

Signed-off-by: Eugen Hristev <eugen.hristev@linaro.org>
---
 include/linux/printk.h   | 1 +
 init/version-timestamp.c | 1 +
 init/version.c           | 1 +
 3 files changed, 3 insertions(+)

diff --git a/include/linux/printk.h b/include/linux/printk.h
index 45c663124c9b..5bc617222948 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -12,6 +12,7 @@
 struct console;
 
 extern const char linux_banner[];
+extern const int banner_len;
 extern const char linux_proc_banner[];
 
 extern int oops_in_progress;	/* If set, an oops, panic(), BUG() or die() is in progress */
diff --git a/init/version-timestamp.c b/init/version-timestamp.c
index 043cbf80a766..1fdd795be747 100644
--- a/init/version-timestamp.c
+++ b/init/version-timestamp.c
@@ -28,3 +28,4 @@ struct uts_namespace init_uts_ns = {
 const char linux_banner[] =
 	"Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@"
 	LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";
+const int banner_len = sizeof(linux_banner);
diff --git a/init/version.c b/init/version.c
index 94c96f6fbfe6..68d16748b081 100644
--- a/init/version.c
+++ b/init/version.c
@@ -48,6 +48,7 @@ BUILD_LTO_INFO;
 
 struct uts_namespace init_uts_ns __weak;
 const char linux_banner[] __weak;
+const int banner_len __weak;
 
 #include "version-timestamp.c"
 
-- 
2.43.0