Merge tag 'printk-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Print more precise information about the printk log buffer memory
   usage.

 - Make sure that the sysrq title is shown on the console even when
   deferred.

 - Do not enable earlycon by `console=` which is meant to disable the
   default console.

* tag 'printk-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: add dummy printk_force_console_enter/exit helpers
  tty: sysrq: Use printk_force_console context on __handle_sysrq
  printk: Introduce FORCE_CON flag
  printk: Improve memory usage logging during boot
  init: Don't proxy `console=` to earlycon

2 files changed, 31 insertions, 10 deletions

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index a5fbb6ed38ae..ab9af37f6cda 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -248,6 +248,29 @@ static int __init param_setup_earlycon(char *buf)
 }
 early_param("earlycon", param_setup_earlycon);
 
+/*
+ * The `console` parameter is overloaded. It's handled here as an early param
+ * and in `printk.c` as a late param. It's possible to specify an early
+ * `bootconsole` using `earlycon=uartXXXX` (handled above), or via
+ * the `console=uartXXX` alias. See the comment in `8250_early.c`.
+ */
+static int __init param_setup_earlycon_console_alias(char *buf)
+{
+	/*
+	 * A plain `console` parameter must not enable the SPCR `bootconsole`
+	 * like a plain `earlycon` does.
+	 *
+	 * A `console=` parameter that specifies an empty value is used to
+	 * disable the `console`, not the `earlycon` `bootconsole`. The
+	 * disabling of the `console` is handled by `printk.c`.
+	 */
+	if (!buf || !buf[0])
+		return 0;
+
+	return param_setup_earlycon(buf);
+}
+early_param("console", param_setup_earlycon_console_alias);
+
 #ifdef CONFIG_OF_EARLY_FLATTREE
 
 int __init of_setup_earlycon(const struct earlycon_id *match,
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 930b04e3d148..f85ce02e4725 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -583,7 +583,6 @@ static void __sysrq_put_key_op(u8 key, const struct sysrq_key_op *op_p)
 void __handle_sysrq(u8 key, bool check_mask)
 {
 	const struct sysrq_key_op *op_p;
-	int orig_log_level;
 	int orig_suppress_printk;
 	int i;
 
@@ -593,13 +592,12 @@ void __handle_sysrq(u8 key, bool check_mask)
 	rcu_sysrq_start();
 	rcu_read_lock();
 	/*
-	 * Raise the apparent loglevel to maximum so that the sysrq header
-	 * is shown to provide the user with positive feedback.  We do not
-	 * simply emit this at KERN_EMERG as that would change message
-	 * routing in the consumers of /proc/kmsg.
+	 * Enter in the force_console context so that sysrq header is shown to
+	 * provide the user with positive feedback.  We do not simply emit this
+	 * at KERN_EMERG as that would change message routing in the consumers
+	 * of /proc/kmsg.
 	 */
-	orig_log_level = console_loglevel;
-	console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
+	printk_force_console_enter();
 
 	op_p = __sysrq_get_key_op(key);
 	if (op_p) {
@@ -609,11 +607,11 @@ void __handle_sysrq(u8 key, bool check_mask)
 		 */
 		if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
 			pr_info("%s\n", op_p->action_msg);
-			console_loglevel = orig_log_level;
+			printk_force_console_exit();
 			op_p->handler(key);
 		} else {
 			pr_info("This sysrq operation is disabled.\n");
-			console_loglevel = orig_log_level;
+			printk_force_console_exit();
 		}
 	} else {
 		pr_info("HELP : ");
@@ -631,7 +629,7 @@ void __handle_sysrq(u8 key, bool check_mask)
 			}
 		}
 		pr_cont("\n");
-		console_loglevel = orig_log_level;
+		printk_force_console_exit();
 	}
 	rcu_read_unlock();
 	rcu_sysrq_end();