linux-stable/drivers/s390/char/sclp_async.c
Peter Huewe d5f4d113cb [S390] sclp_async: Use kstrtoul_from_user
This patch replaces the code for getting an unsigned long from a
userspace buffer by a simple call to kstroul_from_user.
This makes it easier to read and less error prone.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2011-08-03 16:44:20 +02:00

211 lines
5 KiB
C

/*
* Enable Asynchronous Notification via SCLP.
*
* Copyright IBM Corp. 2009
* Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/sysctl.h>
#include <linux/utsname.h>
#include "sclp.h"
static int callhome_enabled;
static struct sclp_req *request;
static struct sclp_async_sccb *sccb;
static int sclp_async_send_wait(char *message);
static struct ctl_table_header *callhome_sysctl_header;
static DEFINE_SPINLOCK(sclp_async_lock);
#define SCLP_NORMAL_WRITE 0x00
struct async_evbuf {
struct evbuf_header header;
u64 reserved;
u8 rflags;
u8 empty;
u8 rtype;
u8 otype;
char comp_id[12];
char data[3000]; /* there is still some space left */
} __attribute__((packed));
struct sclp_async_sccb {
struct sccb_header header;
struct async_evbuf evbuf;
} __attribute__((packed));
static struct sclp_register sclp_async_register = {
.send_mask = EVTYP_ASYNC_MASK,
};
static int call_home_on_panic(struct notifier_block *self,
unsigned long event, void *data)
{
strncat(data, init_utsname()->nodename,
sizeof(init_utsname()->nodename));
sclp_async_send_wait(data);
return NOTIFY_DONE;
}
static struct notifier_block call_home_panic_nb = {
.notifier_call = call_home_on_panic,
.priority = INT_MAX,
};
static int proc_handler_callhome(struct ctl_table *ctl, int write,
void __user *buffer, size_t *count,
loff_t *ppos)
{
unsigned long val;
int len, rc;
char buf[3];
if (!*count || (*ppos && !write)) {
*count = 0;
return 0;
}
if (!write) {
len = snprintf(buf, sizeof(buf), "%d\n", callhome_enabled);
rc = copy_to_user(buffer, buf, sizeof(buf));
if (rc != 0)
return -EFAULT;
} else {
len = *count;
rc = kstrtoul_from_user(buffer, len, 0, &val);
if (rc)
return rc;
if (val != 0 && val != 1)
return -EINVAL;
callhome_enabled = val;
}
*count = len;
*ppos += len;
return 0;
}
static struct ctl_table callhome_table[] = {
{
.procname = "callhome",
.mode = 0644,
.proc_handler = proc_handler_callhome,
},
{}
};
static struct ctl_table kern_dir_table[] = {
{
.procname = "kernel",
.maxlen = 0,
.mode = 0555,
.child = callhome_table,
},
{}
};
/*
* Function used to transfer asynchronous notification
* records which waits for send completion
*/
static int sclp_async_send_wait(char *message)
{
struct async_evbuf *evb;
int rc;
unsigned long flags;
if (!callhome_enabled)
return 0;
sccb->evbuf.header.type = EVTYP_ASYNC;
sccb->evbuf.rtype = 0xA5;
sccb->evbuf.otype = 0x00;
evb = &sccb->evbuf;
request->command = SCLP_CMDW_WRITE_EVENT_DATA;
request->sccb = sccb;
request->status = SCLP_REQ_FILLED;
strncpy(sccb->evbuf.data, message, sizeof(sccb->evbuf.data));
/*
* Retain Queue
* e.g. 5639CC140 500 Red Hat RHEL5 Linux for zSeries (RHEL AS)
*/
strncpy(sccb->evbuf.comp_id, "000000000", sizeof(sccb->evbuf.comp_id));
sccb->evbuf.header.length = sizeof(sccb->evbuf);
sccb->header.length = sizeof(sccb->evbuf) + sizeof(sccb->header);
sccb->header.function_code = SCLP_NORMAL_WRITE;
rc = sclp_add_request(request);
if (rc)
return rc;
spin_lock_irqsave(&sclp_async_lock, flags);
while (request->status != SCLP_REQ_DONE &&
request->status != SCLP_REQ_FAILED) {
sclp_sync_wait();
}
spin_unlock_irqrestore(&sclp_async_lock, flags);
if (request->status != SCLP_REQ_DONE)
return -EIO;
rc = ((struct sclp_async_sccb *)
request->sccb)->header.response_code;
if (rc != 0x0020)
return -EIO;
if (evb->header.flags != 0x80)
return -EIO;
return rc;
}
static int __init sclp_async_init(void)
{
int rc;
rc = sclp_register(&sclp_async_register);
if (rc)
return rc;
rc = -EOPNOTSUPP;
if (!(sclp_async_register.sclp_receive_mask & EVTYP_ASYNC_MASK))
goto out_sclp;
rc = -ENOMEM;
callhome_sysctl_header = register_sysctl_table(kern_dir_table);
if (!callhome_sysctl_header)
goto out_sclp;
request = kzalloc(sizeof(struct sclp_req), GFP_KERNEL);
sccb = (struct sclp_async_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (!request || !sccb)
goto out_mem;
rc = atomic_notifier_chain_register(&panic_notifier_list,
&call_home_panic_nb);
if (!rc)
goto out;
out_mem:
kfree(request);
free_page((unsigned long) sccb);
unregister_sysctl_table(callhome_sysctl_header);
out_sclp:
sclp_unregister(&sclp_async_register);
out:
return rc;
}
module_init(sclp_async_init);
static void __exit sclp_async_exit(void)
{
atomic_notifier_chain_unregister(&panic_notifier_list,
&call_home_panic_nb);
unregister_sysctl_table(callhome_sysctl_header);
sclp_unregister(&sclp_async_register);
free_page((unsigned long) sccb);
kfree(request);
}
module_exit(sclp_async_exit);
MODULE_AUTHOR("Copyright IBM Corp. 2009");
MODULE_AUTHOR("Hans-Joachim Picht <hans@linux.vnet.ibm.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SCLP Asynchronous Notification Records");