linux/drivers/macintosh/ans-lcd.c
Linus Torvalds 96d4f267e4 Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00

205 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* /dev/lcd driver for Apple Network Servers.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/io.h>
#include "ans-lcd.h"
#define ANSLCD_ADDR 0xf301c000
#define ANSLCD_CTRL_IX 0x00
#define ANSLCD_DATA_IX 0x10
static unsigned long anslcd_short_delay = 80;
static unsigned long anslcd_long_delay = 3280;
static volatile unsigned char __iomem *anslcd_ptr;
static DEFINE_MUTEX(anslcd_mutex);
#undef DEBUG
static void
anslcd_write_byte_ctrl ( unsigned char c )
{
#ifdef DEBUG
printk(KERN_DEBUG "LCD: CTRL byte: %02x\n",c);
#endif
out_8(anslcd_ptr + ANSLCD_CTRL_IX, c);
switch(c) {
case 1:
case 2:
case 3:
udelay(anslcd_long_delay); break;
default: udelay(anslcd_short_delay);
}
}
static void
anslcd_write_byte_data ( unsigned char c )
{
out_8(anslcd_ptr + ANSLCD_DATA_IX, c);
udelay(anslcd_short_delay);
}
static ssize_t
anslcd_write( struct file * file, const char __user * buf,
size_t count, loff_t *ppos )
{
const char __user *p = buf;
int i;
#ifdef DEBUG
printk(KERN_DEBUG "LCD: write\n");
#endif
if (!access_ok(buf, count))
return -EFAULT;
mutex_lock(&anslcd_mutex);
for ( i = *ppos; count > 0; ++i, ++p, --count )
{
char c;
__get_user(c, p);
anslcd_write_byte_data( c );
}
mutex_unlock(&anslcd_mutex);
*ppos = i;
return p - buf;
}
static long
anslcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
char ch, __user *temp;
long ret = 0;
#ifdef DEBUG
printk(KERN_DEBUG "LCD: ioctl(%d,%d)\n",cmd,arg);
#endif
mutex_lock(&anslcd_mutex);
switch ( cmd )
{
case ANSLCD_CLEAR:
anslcd_write_byte_ctrl ( 0x38 );
anslcd_write_byte_ctrl ( 0x0f );
anslcd_write_byte_ctrl ( 0x06 );
anslcd_write_byte_ctrl ( 0x01 );
anslcd_write_byte_ctrl ( 0x02 );
break;
case ANSLCD_SENDCTRL:
temp = (char __user *) arg;
__get_user(ch, temp);
for (; ch; temp++) { /* FIXME: This is ugly, but should work, as a \0 byte is not a valid command code */
anslcd_write_byte_ctrl ( ch );
__get_user(ch, temp);
}
break;
case ANSLCD_SETSHORTDELAY:
if (!capable(CAP_SYS_ADMIN))
ret =-EACCES;
else
anslcd_short_delay=arg;
break;
case ANSLCD_SETLONGDELAY:
if (!capable(CAP_SYS_ADMIN))
ret = -EACCES;
else
anslcd_long_delay=arg;
break;
default:
ret = -EINVAL;
}
mutex_unlock(&anslcd_mutex);
return ret;
}
static int
anslcd_open( struct inode * inode, struct file * file )
{
return 0;
}
const struct file_operations anslcd_fops = {
.write = anslcd_write,
.unlocked_ioctl = anslcd_ioctl,
.open = anslcd_open,
.llseek = default_llseek,
};
static struct miscdevice anslcd_dev = {
ANSLCD_MINOR,
"anslcd",
&anslcd_fops
};
const char anslcd_logo[] = "********************" /* Line #1 */
"* LINUX! *" /* Line #3 */
"* Welcome to *" /* Line #2 */
"********************"; /* Line #4 */
static int __init
anslcd_init(void)
{
int a;
int retval;
struct device_node* node;
node = of_find_node_by_name(NULL, "lcd");
if (!node || !of_node_name_eq(node->parent, "gc")) {
of_node_put(node);
return -ENODEV;
}
of_node_put(node);
anslcd_ptr = ioremap(ANSLCD_ADDR, 0x20);
retval = misc_register(&anslcd_dev);
if(retval < 0){
printk(KERN_INFO "LCD: misc_register failed\n");
iounmap(anslcd_ptr);
return retval;
}
#ifdef DEBUG
printk(KERN_DEBUG "LCD: init\n");
#endif
mutex_lock(&anslcd_mutex);
anslcd_write_byte_ctrl ( 0x38 );
anslcd_write_byte_ctrl ( 0x0c );
anslcd_write_byte_ctrl ( 0x06 );
anslcd_write_byte_ctrl ( 0x01 );
anslcd_write_byte_ctrl ( 0x02 );
for(a=0;a<80;a++) {
anslcd_write_byte_data(anslcd_logo[a]);
}
mutex_unlock(&anslcd_mutex);
return 0;
}
static void __exit
anslcd_exit(void)
{
misc_deregister(&anslcd_dev);
iounmap(anslcd_ptr);
}
module_init(anslcd_init);
module_exit(anslcd_exit);
MODULE_LICENSE("GPL v2");