From 59cfc45f17d6d1dda2990e6f5a94df24a18330b8 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Tue, 5 May 2015 08:26:27 +0200 Subject: [PATCH] serial: 8250: Do nothing if nr_uarts=0 When nr_uarts was set to 0 (via config or 8250_core.nr_uarts), we crash early on x86 because serial8250_isa_init_ports dereferences base_ops which remains NULL. In fact, there is nothing to do for all the callers of serial8250_isa_init_ports if there are no uarts. Based on suggestions by Peter Hurley. Signed-off-by: Jan Kiszka Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 01cecd52b909..5521ff83303f 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -3535,6 +3535,9 @@ static struct console univ8250_console = { static int __init univ8250_console_init(void) { + if (nr_uarts == 0) + return -ENODEV; + serial8250_isa_init_ports(); register_console(&univ8250_console); return 0; @@ -3565,7 +3568,7 @@ int __init early_serial_setup(struct uart_port *port) { struct uart_port *p; - if (port->line >= ARRAY_SIZE(serial8250_ports)) + if (port->line >= ARRAY_SIZE(serial8250_ports) || nr_uarts == 0) return -ENODEV; serial8250_isa_init_ports(); @@ -3932,6 +3935,9 @@ static int __init serial8250_init(void) { int ret; + if (nr_uarts == 0) + return -ENODEV; + serial8250_isa_init_ports(); printk(KERN_INFO "Serial: 8250/16550 driver, " -- 2.45.2