From 177435e2ea71dd66b838d02b4de58f79babf903c Mon Sep 17 00:00:00 2001
From: Tao Huang <huangtao@rock-chips.com>
Date: Tue, 14 Nov 2017 15:02:57 +0800
Subject: [PATCH] pstore/console: ignore log level

When printk to pstore console, we ignore log level. So
/sys/fs/pstore/console-ramoops-0 should keep full kernel log.
This feature enabled with the bool parameter pstore_con_force.

Change-Id: I87ea3418741c117523a9e872ae7ace4dac0cd9d3
Signed-off-by: Tao Huang <huangtao@rock-chips.com>
---
 fs/pstore/Kconfig       | 12 ++++++++
 fs/pstore/platform.c    |  4 +++
 include/linux/console.h |  3 ++
 kernel/printk/printk.c  | 66 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 85 insertions(+)

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index 503086f7f7c1..29943657db25 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -114,6 +114,18 @@ config PSTORE_CONSOLE
 	  When the option is enabled, pstore will log all kernel
 	  messages, even if no oops or panic happened.
 
+config PSTORE_CONSOLE_FORCE
+	bool "Log kernel console messages ignore loglevel setting"
+	depends on PSTORE_CONSOLE
+	help
+	  When the option is enabled, allow all kernel messages
+	  log to the pstore console. Enable this with a kernel bool
+	  parameter like "pstore_con_force=1".
+
+config PSTORE_CONSOLE_FORCE_ON
+	bool "Log kernel console messages ignore loglevel setting on by default"
+	depends on PSTORE_CONSOLE_FORCE
+
 config PSTORE_PMSG
 	bool "Log user space messages"
 	depends on PSTORE
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 4bae3f4fe829..5d089def0436 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -492,7 +492,11 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
 static struct console pstore_console = {
 	.name	= "pstore",
 	.write	= pstore_console_write,
+#ifdef CON_PSTORE
+	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME | CON_PSTORE,
+#else
 	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
+#endif
 	.index	= -1,
 };
 
diff --git a/include/linux/console.h b/include/linux/console.h
index ec9bdb3d7bab..cce6e719a03f 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -141,6 +141,9 @@ static inline int con_debug_leave(void)
 #define CON_ANYTIME	(16) /* Safe to call when cpu is offline */
 #define CON_BRL		(32) /* Used for a braille device */
 #define CON_EXTENDED	(64) /* Use the extended output format a la /dev/kmsg */
+#ifdef CONFIG_PSTORE_CONSOLE_FORCE
+#define CON_PSTORE	(128) /* Print to pstore console anyway */
+#endif
 
 struct console {
 	char	name[16];
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 51904f47f874..6e21a88b1a9a 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1200,7 +1200,11 @@ void __init setup_log_buf(int early)
 		free, (free * 100) / __LOG_BUF_LEN);
 }
 
+#ifdef CONFIG_PSTORE_CONSOLE_FORCE_ON
+static bool __read_mostly ignore_loglevel = true;
+#else
 static bool __read_mostly ignore_loglevel;
+#endif
 
 static int __init ignore_loglevel_setup(char *str)
 {
@@ -1215,6 +1219,61 @@ module_param(ignore_loglevel, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(ignore_loglevel,
 		 "ignore loglevel setting (prints all kernel messages to the console)");
 
+#ifdef CONFIG_PSTORE_CONSOLE_FORCE
+static bool __read_mostly pstore_con_force = IS_ENABLED(CONFIG_PSTORE_CONSOLE_FORCE_ON);
+
+static int __init pstore_con_force_setup(char *str)
+{
+	bool force;
+	int ret = strtobool(str, &force);
+
+	if (ret)
+		return ret;
+
+	ignore_loglevel = force;
+	pstore_con_force = force;
+	if (force)
+		pr_info("debug: pstore console ignoring loglevel setting.\n");
+
+	return 0;
+}
+
+early_param("pstore_con_force", pstore_con_force_setup);
+module_param(pstore_con_force, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(pstore_con_force,
+		 "ignore loglevel setting (prints all kernel messages to the pstore console)");
+
+static void call_console_drivers_level(int level, const char *ext_text, size_t ext_len,
+				       const char *text, size_t len)
+{
+	struct console *con;
+
+	trace_console_rcuidle(text, len);
+
+	if (!console_drivers)
+		return;
+
+	for_each_console(con) {
+		if (pstore_con_force &&
+		    !(con->flags & CON_PSTORE) && level >= console_loglevel)
+			continue;
+		if (exclusive_console && con != exclusive_console)
+			continue;
+		if (!(con->flags & CON_ENABLED))
+			continue;
+		if (!con->write)
+			continue;
+		if (!cpu_online(smp_processor_id()) &&
+		    !(con->flags & CON_ANYTIME))
+			continue;
+		if (con->flags & CON_EXTENDED)
+			con->write(con, ext_text, ext_len);
+		else
+			con->write(con, text, len);
+	}
+}
+#endif
+
 static bool suppress_message_printing(int level)
 {
 	return (level >= console_loglevel && !ignore_loglevel);
@@ -1770,6 +1829,9 @@ static int console_trylock_spinning(void)
  * log_buf[start] to log_buf[end - 1].
  * The console_lock must be held.
  */
+#ifdef CONFIG_PSTORE_CONSOLE_FORCE
+__maybe_unused
+#endif
 static void call_console_drivers(const char *ext_text, size_t ext_len,
 				 const char *text, size_t len)
 {
@@ -2486,7 +2548,11 @@ skip:
 		console_lock_spinning_enable();
 
 		stop_critical_timings();	/* don't trace print latency */
+#ifdef CONFIG_PSTORE_CONSOLE_FORCE
+		call_console_drivers_level(msg->level, ext_text, ext_len, text, len);
+#else
 		call_console_drivers(ext_text, ext_len, text, len);
+#endif
 		start_critical_timings();
 
 		if (console_lock_spinning_disable_and_check()) {