linux/drivers/s390/net/ctcm_sysfs.c
Alexandra Winter 2c50c6867c s390/ctcm: fix variable dereferenced before check
Found by cppcheck and smatch.
smatch complains about
drivers/s390/net/ctcm_sysfs.c:43 ctcm_buffer_write() warn: variable dereferenced before check 'priv' (see line 42)

Fixes: 3c09e2647b ("ctcm: rename READ/WRITE defines to avoid redefinitions")
Reported-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-11 12:31:01 +01:00

211 lines
5.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2007, 2007
* Authors: Peter Tiedemann (ptiedem@de.ibm.com)
*
*/
#undef DEBUG
#undef DEBUGDATA
#undef DEBUGCCW
#define KMSG_COMPONENT "ctcm"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include "ctcm_main.h"
/*
* sysfs attributes
*/
static ssize_t ctcm_buffer_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ctcm_priv *priv = dev_get_drvdata(dev);
if (!priv)
return -ENODEV;
return sprintf(buf, "%d\n", priv->buffer_size);
}
static ssize_t ctcm_buffer_write(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct net_device *ndev;
unsigned int bs1;
struct ctcm_priv *priv = dev_get_drvdata(dev);
int rc;
if (!(priv && priv->channel[CTCM_READ] &&
priv->channel[CTCM_READ]->netdev)) {
CTCM_DBF_TEXT(SETUP, CTC_DBF_ERROR, "bfnondev");
return -ENODEV;
}
ndev = priv->channel[CTCM_READ]->netdev;
rc = kstrtouint(buf, 0, &bs1);
if (rc)
goto einval;
if (bs1 > CTCM_BUFSIZE_LIMIT)
goto einval;
if (bs1 < (576 + LL_HEADER_LENGTH + 2))
goto einval;
priv->buffer_size = bs1; /* just to overwrite the default */
if ((ndev->flags & IFF_RUNNING) &&
(bs1 < (ndev->mtu + LL_HEADER_LENGTH + 2)))
goto einval;
priv->channel[CTCM_READ]->max_bufsize = bs1;
priv->channel[CTCM_WRITE]->max_bufsize = bs1;
if (!(ndev->flags & IFF_RUNNING))
ndev->mtu = bs1 - LL_HEADER_LENGTH - 2;
priv->channel[CTCM_READ]->flags |= CHANNEL_FLAGS_BUFSIZE_CHANGED;
priv->channel[CTCM_WRITE]->flags |= CHANNEL_FLAGS_BUFSIZE_CHANGED;
CTCM_DBF_DEV(SETUP, ndev, buf);
return count;
einval:
CTCM_DBF_DEV(SETUP, ndev, "buff_err");
return -EINVAL;
}
static void ctcm_print_statistics(struct ctcm_priv *priv)
{
char *sbuf;
char *p;
if (!priv)
return;
sbuf = kmalloc(2048, GFP_KERNEL);
if (sbuf == NULL)
return;
p = sbuf;
p += sprintf(p, " Device FSM state: %s\n",
fsm_getstate_str(priv->fsm));
p += sprintf(p, " RX channel FSM state: %s\n",
fsm_getstate_str(priv->channel[CTCM_READ]->fsm));
p += sprintf(p, " TX channel FSM state: %s\n",
fsm_getstate_str(priv->channel[CTCM_WRITE]->fsm));
p += sprintf(p, " Max. TX buffer used: %ld\n",
priv->channel[WRITE]->prof.maxmulti);
p += sprintf(p, " Max. chained SKBs: %ld\n",
priv->channel[WRITE]->prof.maxcqueue);
p += sprintf(p, " TX single write ops: %ld\n",
priv->channel[WRITE]->prof.doios_single);
p += sprintf(p, " TX multi write ops: %ld\n",
priv->channel[WRITE]->prof.doios_multi);
p += sprintf(p, " Netto bytes written: %ld\n",
priv->channel[WRITE]->prof.txlen);
p += sprintf(p, " Max. TX IO-time: %u\n",
jiffies_to_usecs(priv->channel[WRITE]->prof.tx_time));
printk(KERN_INFO "Statistics for %s:\n%s",
priv->channel[CTCM_WRITE]->netdev->name, sbuf);
kfree(sbuf);
return;
}
static ssize_t stats_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
struct ctcm_priv *priv = dev_get_drvdata(dev);
if (!priv || gdev->state != CCWGROUP_ONLINE)
return -ENODEV;
ctcm_print_statistics(priv);
return sprintf(buf, "0\n");
}
static ssize_t stats_write(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct ctcm_priv *priv = dev_get_drvdata(dev);
if (!priv)
return -ENODEV;
/* Reset statistics */
memset(&priv->channel[WRITE]->prof, 0,
sizeof(priv->channel[CTCM_WRITE]->prof));
return count;
}
static ssize_t ctcm_proto_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ctcm_priv *priv = dev_get_drvdata(dev);
if (!priv)
return -ENODEV;
return sprintf(buf, "%d\n", priv->protocol);
}
static ssize_t ctcm_proto_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int value, rc;
struct ctcm_priv *priv = dev_get_drvdata(dev);
if (!priv)
return -ENODEV;
rc = kstrtoint(buf, 0, &value);
if (rc ||
!((value == CTCM_PROTO_S390) ||
(value == CTCM_PROTO_LINUX) ||
(value == CTCM_PROTO_MPC) ||
(value == CTCM_PROTO_OS390)))
return -EINVAL;
priv->protocol = value;
CTCM_DBF_DEV(SETUP, dev, buf);
return count;
}
static const char *ctcm_type[] = {
"not a channel",
"CTC/A",
"FICON channel",
"ESCON channel",
"unknown channel type",
"unsupported channel type",
};
static ssize_t ctcm_type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ccwgroup_device *cgdev;
cgdev = to_ccwgroupdev(dev);
if (!cgdev)
return -ENODEV;
return sprintf(buf, "%s\n",
ctcm_type[cgdev->cdev[0]->id.driver_info]);
}
static DEVICE_ATTR(buffer, 0644, ctcm_buffer_show, ctcm_buffer_write);
static DEVICE_ATTR(protocol, 0644, ctcm_proto_show, ctcm_proto_store);
static DEVICE_ATTR(type, 0444, ctcm_type_show, NULL);
static DEVICE_ATTR(stats, 0644, stats_show, stats_write);
static struct attribute *ctcm_attr[] = {
&dev_attr_protocol.attr,
&dev_attr_type.attr,
&dev_attr_buffer.attr,
&dev_attr_stats.attr,
NULL,
};
static struct attribute_group ctcm_attr_group = {
.attrs = ctcm_attr,
};
const struct attribute_group *ctcm_attr_groups[] = {
&ctcm_attr_group,
NULL,
};