pstore: Add console log messages support

Pstore doesn't support logging kernel messages in run-time, it only
dumps dmesg when kernel oopses/panics. This makes pstore useless for
debugging hangs caused by HW issues or improper use of HW (e.g.
weird device inserted -> driver tried to write a reserved bits ->
SoC hanged. In that case we don't get any messages in the pstore.

Therefore, let's add a runtime logging support: PSTORE_TYPE_CONSOLE.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index 23ade26..d044de6 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -12,6 +12,13 @@
 	   If you don't have a platform persistent store driver,
 	   say N.
 
+config PSTORE_CONSOLE
+	bool "Log kernel console messages"
+	depends on PSTORE
+	help
+	  When the option is enabled, pstore will log all kernel
+	  messages, even if no oops or panic happened.
+
 config PSTORE_RAM
 	tristate "Log panic/oops to a RAM buffer"
 	depends on PSTORE