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sunsu: Fix panic in case of nonexistent port at "console=ttySY" cmdline option

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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: <sunsu_console_setup+0x78/0xe0>
RPC: <sunsu_console_setup+0x74/0xe0>
I7: <register_console+0x378/0x3e0>
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 <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tkhai Kirill 2013-02-23 23:01:15 +00:00 committed by David S. Miller
parent b0af9cd9aa
commit cb29529ea0
1 changed files with 9 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/tty/serial/sunsu.c
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@ -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;