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linux/drivers/s390/char/monwriter.c
Gerald Schaefer 3cf11d776a s390/monwriter: fix smatch warning for strcpy()
This patch fixes the following smatch warning:
monwrite_diag() error: strcpy() '"LNXAPPL"' too large for 'id.prod_nr'
(8 vs 7)
Using strcpy() is wrong, because it also copies the terminating null
byte, but in this case the extra copied null byte will be overwritten
right after the strcpy(), so there is no real problem here.
Use strncpy() to fix the warning.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24 17:17:08 +02:00

400 lines
9.6 KiB
C

/*
* Character device driver for writing z/VM *MONITOR service records.
*
* Copyright IBM Corp. 2006, 2009
*
* Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
*/
#define KMSG_COMPONENT "monwriter"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/ctype.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
#include <asm/appldata.h>
#include <asm/monwriter.h>
#define MONWRITE_MAX_DATALEN 4010
static int mon_max_bufs = 255;
static int mon_buf_count;
struct mon_buf {
struct list_head list;
struct monwrite_hdr hdr;
int diag_done;
char *data;
};
static LIST_HEAD(mon_priv_list);
struct mon_private {
struct list_head priv_list;
struct list_head list;
struct monwrite_hdr hdr;
size_t hdr_to_read;
size_t data_to_read;
struct mon_buf *current_buf;
struct mutex thread_mutex;
};
/*
* helper functions
*/
static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn)
{
struct appldata_product_id id;
int rc;
strncpy(id.prod_nr, "LNXAPPL", 7);
id.prod_fn = myhdr->applid;
id.record_nr = myhdr->record_num;
id.version_nr = myhdr->version;
id.release_nr = myhdr->release;
id.mod_lvl = myhdr->mod_level;
rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen);
if (rc <= 0)
return rc;
pr_err("Writing monitor data failed with rc=%i\n", rc);
if (rc == 5)
return -EPERM;
return -EINVAL;
}
static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv,
struct monwrite_hdr *monhdr)
{
struct mon_buf *entry, *next;
list_for_each_entry_safe(entry, next, &monpriv->list, list)
if ((entry->hdr.mon_function == monhdr->mon_function ||
monhdr->mon_function == MONWRITE_STOP_INTERVAL) &&
entry->hdr.applid == monhdr->applid &&
entry->hdr.record_num == monhdr->record_num &&
entry->hdr.version == monhdr->version &&
entry->hdr.release == monhdr->release &&
entry->hdr.mod_level == monhdr->mod_level)
return entry;
return NULL;
}
static int monwrite_new_hdr(struct mon_private *monpriv)
{
struct monwrite_hdr *monhdr = &monpriv->hdr;
struct mon_buf *monbuf;
int rc = 0;
if (monhdr->datalen > MONWRITE_MAX_DATALEN ||
monhdr->mon_function > MONWRITE_START_CONFIG ||
monhdr->hdrlen != sizeof(struct monwrite_hdr))
return -EINVAL;
monbuf = NULL;
if (monhdr->mon_function != MONWRITE_GEN_EVENT)
monbuf = monwrite_find_hdr(monpriv, monhdr);
if (monbuf) {
if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
monhdr->datalen = monbuf->hdr.datalen;
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_STOP_REC);
list_del(&monbuf->list);
mon_buf_count--;
kfree(monbuf->data);
kfree(monbuf);
monbuf = NULL;
}
} else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) {
if (mon_buf_count >= mon_max_bufs)
return -ENOSPC;
monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
if (!monbuf)
return -ENOMEM;
monbuf->data = kzalloc(monhdr->datalen,
GFP_KERNEL | GFP_DMA);
if (!monbuf->data) {
kfree(monbuf);
return -ENOMEM;
}
monbuf->hdr = *monhdr;
list_add_tail(&monbuf->list, &monpriv->list);
if (monhdr->mon_function != MONWRITE_GEN_EVENT)
mon_buf_count++;
}
monpriv->current_buf = monbuf;
return rc;
}
static int monwrite_new_data(struct mon_private *monpriv)
{
struct monwrite_hdr *monhdr = &monpriv->hdr;
struct mon_buf *monbuf = monpriv->current_buf;
int rc = 0;
switch (monhdr->mon_function) {
case MONWRITE_START_INTERVAL:
if (!monbuf->diag_done) {
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_START_INTERVAL_REC);
monbuf->diag_done = 1;
}
break;
case MONWRITE_START_CONFIG:
if (!monbuf->diag_done) {
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_START_CONFIG_REC);
monbuf->diag_done = 1;
}
break;
case MONWRITE_GEN_EVENT:
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_GEN_EVENT_REC);
list_del(&monpriv->current_buf->list);
kfree(monpriv->current_buf->data);
kfree(monpriv->current_buf);
monpriv->current_buf = NULL;
break;
default:
/* monhdr->mon_function is checked in monwrite_new_hdr */
BUG();
}
return rc;
}
/*
* file operations
*/
static int monwrite_open(struct inode *inode, struct file *filp)
{
struct mon_private *monpriv;
monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
if (!monpriv)
return -ENOMEM;
INIT_LIST_HEAD(&monpriv->list);
monpriv->hdr_to_read = sizeof(monpriv->hdr);
mutex_init(&monpriv->thread_mutex);
filp->private_data = monpriv;
list_add_tail(&monpriv->priv_list, &mon_priv_list);
return nonseekable_open(inode, filp);
}
static int monwrite_close(struct inode *inode, struct file *filp)
{
struct mon_private *monpriv = filp->private_data;
struct mon_buf *entry, *next;
list_for_each_entry_safe(entry, next, &monpriv->list, list) {
if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
monwrite_diag(&entry->hdr, entry->data,
APPLDATA_STOP_REC);
mon_buf_count--;
list_del(&entry->list);
kfree(entry->data);
kfree(entry);
}
list_del(&monpriv->priv_list);
kfree(monpriv);
return 0;
}
static ssize_t monwrite_write(struct file *filp, const char __user *data,
size_t count, loff_t *ppos)
{
struct mon_private *monpriv = filp->private_data;
size_t len, written;
void *to;
int rc;
mutex_lock(&monpriv->thread_mutex);
for (written = 0; written < count; ) {
if (monpriv->hdr_to_read) {
len = min(count - written, monpriv->hdr_to_read);
to = (char *) &monpriv->hdr +
sizeof(monpriv->hdr) - monpriv->hdr_to_read;
if (copy_from_user(to, data + written, len)) {
rc = -EFAULT;
goto out_error;
}
monpriv->hdr_to_read -= len;
written += len;
if (monpriv->hdr_to_read > 0)
continue;
rc = monwrite_new_hdr(monpriv);
if (rc)
goto out_error;
monpriv->data_to_read = monpriv->current_buf ?
monpriv->current_buf->hdr.datalen : 0;
}
if (monpriv->data_to_read) {
len = min(count - written, monpriv->data_to_read);
to = monpriv->current_buf->data +
monpriv->hdr.datalen - monpriv->data_to_read;
if (copy_from_user(to, data + written, len)) {
rc = -EFAULT;
goto out_error;
}
monpriv->data_to_read -= len;
written += len;
if (monpriv->data_to_read > 0)
continue;
rc = monwrite_new_data(monpriv);
if (rc)
goto out_error;
}
monpriv->hdr_to_read = sizeof(monpriv->hdr);
}
mutex_unlock(&monpriv->thread_mutex);
return written;
out_error:
monpriv->data_to_read = 0;
monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
mutex_unlock(&monpriv->thread_mutex);
return rc;
}
static const struct file_operations monwrite_fops = {
.owner = THIS_MODULE,
.open = &monwrite_open,
.release = &monwrite_close,
.write = &monwrite_write,
.llseek = noop_llseek,
};
static struct miscdevice mon_dev = {
.name = "monwriter",
.fops = &monwrite_fops,
.minor = MISC_DYNAMIC_MINOR,
};
/*
* suspend/resume
*/
static int monwriter_freeze(struct device *dev)
{
struct mon_private *monpriv;
struct mon_buf *monbuf;
list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
list_for_each_entry(monbuf, &monpriv->list, list) {
if (monbuf->hdr.mon_function != MONWRITE_GEN_EVENT)
monwrite_diag(&monbuf->hdr, monbuf->data,
APPLDATA_STOP_REC);
}
}
return 0;
}
static int monwriter_restore(struct device *dev)
{
struct mon_private *monpriv;
struct mon_buf *monbuf;
list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
list_for_each_entry(monbuf, &monpriv->list, list) {
if (monbuf->hdr.mon_function == MONWRITE_START_INTERVAL)
monwrite_diag(&monbuf->hdr, monbuf->data,
APPLDATA_START_INTERVAL_REC);
if (monbuf->hdr.mon_function == MONWRITE_START_CONFIG)
monwrite_diag(&monbuf->hdr, monbuf->data,
APPLDATA_START_CONFIG_REC);
}
}
return 0;
}
static int monwriter_thaw(struct device *dev)
{
return monwriter_restore(dev);
}
static const struct dev_pm_ops monwriter_pm_ops = {
.freeze = monwriter_freeze,
.thaw = monwriter_thaw,
.restore = monwriter_restore,
};
static struct platform_driver monwriter_pdrv = {
.driver = {
.name = "monwriter",
.owner = THIS_MODULE,
.pm = &monwriter_pm_ops,
},
};
static struct platform_device *monwriter_pdev;
/*
* module init/exit
*/
static int __init mon_init(void)
{
int rc;
if (!MACHINE_IS_VM)
return -ENODEV;
rc = platform_driver_register(&monwriter_pdrv);
if (rc)
return rc;
monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
0);
if (IS_ERR(monwriter_pdev)) {
rc = PTR_ERR(monwriter_pdev);
goto out_driver;
}
/*
* misc_register() has to be the last action in module_init(), because
* file operations will be available right after this.
*/
rc = misc_register(&mon_dev);
if (rc)
goto out_device;
return 0;
out_device:
platform_device_unregister(monwriter_pdev);
out_driver:
platform_driver_unregister(&monwriter_pdrv);
return rc;
}
static void __exit mon_exit(void)
{
misc_deregister(&mon_dev);
platform_device_unregister(monwriter_pdev);
platform_driver_unregister(&monwriter_pdrv);
}
module_init(mon_init);
module_exit(mon_exit);
module_param_named(max_bufs, mon_max_bufs, int, 0644);
MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
"that can be active at one time");
MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
MODULE_DESCRIPTION("Character device driver for writing z/VM "
"APPLDATA monitor records.");
MODULE_LICENSE("GPL");