linux/drivers/char/hvc_vio.c
Nicolas Palix dc42149fcc drivers/hvc: Add missing of_node_put
of_node_put is needed before discarding a value received from
of_find_node_by_name, e.g., in error handling code or when the device
node is no longer used.

The semantic match that catches the bug is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression struct device_node *n;
position p1, p2;
statement S1,S2;
expression E,E1;
expression *ptr != NULL;
@@

(
if (!(n@p1 = of_find_node_by_name(...))) S1
|
n@p1 = of_find_node_by_name(...)
)
<... when != of_node_put(n)
    when != if (...) { <+... of_node_put(n) ...+> }
    when != true !n  || ...
    when != n = E
    when != E = n
if (!n || ...) S2
...>
(
  return \(0\|<+...n...+>\|ptr\);
|
return@p2 ...;
|
n = E1
|
E1 = n
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s of_find_node_by_name %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-03 21:04:09 +11:00

174 lines
4.2 KiB
C

/*
* vio driver interface to hvc_console.c
*
* This code was moved here to allow the remaing code to be reused as a
* generic polling mode with semi-reliable transport driver core to the
* console and tty subsystems.
*
*
* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
* Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
* Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
* Copyright (C) 2004 IBM Corporation
*
* Additional Author(s):
* Ryan S. Arnold <rsa@us.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/types.h>
#include <linux/init.h>
#include <asm/hvconsole.h>
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/firmware.h>
#include "hvc_console.h"
char hvc_driver_name[] = "hvc_console";
static struct vio_device_id hvc_driver_table[] __devinitdata = {
{"serial", "hvterm1"},
{ "", "" }
};
MODULE_DEVICE_TABLE(vio, hvc_driver_table);
static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
{
unsigned long got;
int i;
/*
* Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
* so we play safe and avoid the situation where got > count which could
* overload the flip buffer.
*/
if (count < SIZE_VIO_GET_CHARS)
return -EAGAIN;
got = hvc_get_chars(vtermno, buf, count);
/*
* Work around a HV bug where it gives us a null
* after every \r. -- paulus
*/
for (i = 1; i < got; ++i) {
if (buf[i] == 0 && buf[i-1] == '\r') {
--got;
if (i < got)
memmove(&buf[i], &buf[i+1],
got - i);
}
}
return got;
}
static struct hv_ops hvc_get_put_ops = {
.get_chars = filtered_get_chars,
.put_chars = hvc_put_chars,
.notifier_add = notifier_add_irq,
.notifier_del = notifier_del_irq,
.notifier_hangup = notifier_hangup_irq,
};
static int __devinit hvc_vio_probe(struct vio_dev *vdev,
const struct vio_device_id *id)
{
struct hvc_struct *hp;
/* probed with invalid parameters. */
if (!vdev || !id)
return -EPERM;
hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
MAX_VIO_PUT_CHARS);
if (IS_ERR(hp))
return PTR_ERR(hp);
dev_set_drvdata(&vdev->dev, hp);
return 0;
}
static int __devexit hvc_vio_remove(struct vio_dev *vdev)
{
struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
return hvc_remove(hp);
}
static struct vio_driver hvc_vio_driver = {
.id_table = hvc_driver_table,
.probe = hvc_vio_probe,
.remove = hvc_vio_remove,
.driver = {
.name = hvc_driver_name,
.owner = THIS_MODULE,
}
};
static int hvc_vio_init(void)
{
int rc;
if (firmware_has_feature(FW_FEATURE_ISERIES))
return -EIO;
/* Register as a vio device to receive callbacks */
rc = vio_register_driver(&hvc_vio_driver);
return rc;
}
module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
static void hvc_vio_exit(void)
{
vio_unregister_driver(&hvc_vio_driver);
}
module_exit(hvc_vio_exit);
/* the device tree order defines our numbering */
static int hvc_find_vtys(void)
{
struct device_node *vty;
int num_found = 0;
for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
vty = of_find_node_by_name(vty, "vty")) {
const uint32_t *vtermno;
/* We have statically defined space for only a certain number
* of console adapters.
*/
if (num_found >= MAX_NR_HVC_CONSOLES) {
of_node_put(vty);
break;
}
vtermno = of_get_property(vty, "reg", NULL);
if (!vtermno)
continue;
if (of_device_is_compatible(vty, "hvterm1")) {
hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
++num_found;
}
}
return num_found;
}
console_initcall(hvc_find_vtys);