1 files changed, 38 insertions, 5 deletions

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 57c70851f22a..ab9af37f6cda 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -67,7 +67,7 @@ static void __init earlycon_init(struct earlycon_device *device,
 	if (*s)
 		earlycon->index = simple_strtoul(s, NULL, 10);
 	len = s - name;
-	strlcpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
+	strscpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
 	earlycon->data = &early_console_dev;
 }
 
@@ -120,10 +120,16 @@ static int __init parse_options(struct earlycon_device *device, char *options)
 	}
 
 	if (options) {
+		char *uartclk;
+
 		device->baud = simple_strtoul(options, NULL, 0);
+		uartclk = strchr(options, ',');
+		if (uartclk && kstrtouint(uartclk + 1, 0, &port->uartclk) < 0)
+			pr_warn("[%s] unsupported earlycon uart clkrate option\n",
+				options);
 		length = min(strcspn(options, " ") + 1,
 			     (size_t)(sizeof(device->options)));
-		strlcpy(device->options, options, length);
+		strscpy(device->options, options, length);
 	}
 
 	return 0;
@@ -139,7 +145,8 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
 		buf = NULL;
 
 	spin_lock_init(&port->lock);
-	port->uartclk = BASE_BAUD * 16;
+	if (!port->uartclk)
+		port->uartclk = BASE_BAUD * 16;
 	if (port->mapbase)
 		port->membase = earlycon_map(port->mapbase, 64);
 
@@ -181,7 +188,7 @@ int __init setup_earlycon(char *buf)
 	if (!buf || !buf[0])
 		return -EINVAL;
 
-	if (early_con.flags & CON_ENABLED)
+	if (console_is_registered(&early_con))
 		return -EALREADY;
 
 again:
@@ -241,6 +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,
@@ -253,6 +283,9 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
 	bool big_endian;
 	u64 addr;
 
+	if (console_is_registered(&early_con))
+		return -EALREADY;
+
 	spin_lock_init(&port->lock);
 	port->iotype = UPIO_MEM;
 	addr = of_flat_dt_translate_address(node);
@@ -301,7 +334,7 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
 
 	if (options) {
 		early_console_dev.baud = simple_strtoul(options, NULL, 0);
-		strlcpy(early_console_dev.options, options,
+		strscpy(early_console_dev.options, options,
 			sizeof(early_console_dev.options));
 	}
 	earlycon_init(&early_console_dev, match->name);