From cb29529ea0030e60ef1bbbf8399a43d397a51526 Mon Sep 17 00:00:00 2001 From: Tkhai Kirill Date: Sat, 23 Feb 2013 23:01:15 +0000 Subject: [PATCH] sunsu: Fix panic in case of nonexistent port at "console=ttySY" cmdline option If a machine has X (X < 4) sunsu ports and cmdline option "console=ttySY" is passed, where X < Y <= 4, than the following panic happens: Unable to handle kernel NULL pointer dereference TPC: RPC: I7: Call Trace: [0000000000453a38] register_console+0x378/0x3e0 [0000000000576fa0] uart_add_one_port+0x2e0/0x340 [000000000057af40] su_probe+0x160/0x2e0 [00000000005b8a4c] platform_drv_probe+0xc/0x20 [00000000005b6c2c] driver_probe_device+0x12c/0x220 [00000000005b6da8] __driver_attach+0x88/0xa0 [00000000005b4df4] bus_for_each_dev+0x54/0xa0 [00000000005b5a54] bus_add_driver+0x154/0x260 [00000000005b7190] driver_register+0x50/0x180 [00000000006d250c] sunsu_init+0x18c/0x1e0 [00000000006c2668] do_one_initcall+0xe8/0x160 [00000000006c282c] kernel_init_freeable+0x12c/0x1e0 [0000000000603764] kernel_init+0x4/0x100 [0000000000405f64] ret_from_syscall+0x1c/0x2c [0000000000000000] (null) 1)Fix the panic; 2)Increment registered port number every successful probe. Signed-off-by: Kirill Tkhai CC: David Miller Signed-off-by: David S. Miller --- drivers/tty/serial/sunsu.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c index e343d66..451687c 100644 --- a/drivers/tty/serial/sunsu.c +++ b/drivers/tty/serial/sunsu.c @@ -968,6 +968,7 @@ static struct uart_ops sunsu_pops = { #define UART_NR 4 static struct uart_sunsu_port sunsu_ports[UART_NR]; +static int nr_inst; /* Number of already registered ports */ #ifdef CONFIG_SERIO @@ -1337,13 +1338,8 @@ static int __init sunsu_console_setup(struct console *co, char *options) printk("Console: ttyS%d (SU)\n", (sunsu_reg.minor - 64) + co->index); - /* - * Check whether an invalid uart number has been specified, and - * if so, search for the first available port that does have - * console support. - */ - if (co->index >= UART_NR) - co->index = 0; + if (co->index > nr_inst) + return -ENODEV; port = &sunsu_ports[co->index].port; /* @@ -1408,7 +1404,6 @@ static enum su_type su_get_type(struct device_node *dp) static int su_probe(struct platform_device *op) { - static int inst; struct device_node *dp = op->dev.of_node; struct uart_sunsu_port *up; struct resource *rp; @@ -1418,16 +1413,16 @@ static int su_probe(struct platform_device *op) type = su_get_type(dp); if (type == SU_PORT_PORT) { - if (inst >= UART_NR) + if (nr_inst >= UART_NR) return -EINVAL; - up = &sunsu_ports[inst]; + up = &sunsu_ports[nr_inst]; } else { up = kzalloc(sizeof(*up), GFP_KERNEL); if (!up) return -ENOMEM; } - up->port.line = inst; + up->port.line = nr_inst; spin_lock_init(&up->port.lock); @@ -1461,6 +1456,8 @@ static int su_probe(struct platform_device *op) } dev_set_drvdata(&op->dev, up); + nr_inst++; + return 0; } @@ -1488,7 +1485,7 @@ static int su_probe(struct platform_device *op) dev_set_drvdata(&op->dev, up); - inst++; + nr_inst++; return 0; -- 2.7.4