linux-stable/drivers/char/dsp56k.c
Dan Carpenter 2419036411 dsp56k: prevent a harmless underflow
There is a mistake here where we don't allow "len" to be zero but we
allow negative lengths.  It's basically harmless in this case, but the
underflow makes my static checker complain.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-14 16:21:53 +09:00

534 lines
12 KiB
C

/*
* The DSP56001 Device Driver, saviour of the Free World(tm)
*
* Authors: Fredrik Noring <noring@nocrew.org>
* lars brinkhoff <lars@nocrew.org>
* Tomas Berndtsson <tomas@nocrew.org>
*
* First version May 1996
*
* History:
* 97-01-29 Tomas Berndtsson,
* Integrated with Linux 2.1.21 kernel sources.
* 97-02-15 Tomas Berndtsson,
* Fixed for kernel 2.1.26
*
* BUGS:
* Hmm... there must be something here :)
*
* Copyright (C) 1996,1997 Fredrik Noring, lars brinkhoff & Tomas Berndtsson
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/major.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/delay.h> /* guess what */
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/firmware.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h> /* For put_user and get_user */
#include <asm/atarihw.h>
#include <asm/traps.h>
#include <asm/dsp56k.h>
/* minor devices */
#define DSP56K_DEV_56001 0 /* The only device so far */
#define TIMEOUT 10 /* Host port timeout in number of tries */
#define MAXIO 2048 /* Maximum number of words before sleep */
#define DSP56K_MAX_BINARY_LENGTH (3*64*1024)
#define DSP56K_TX_INT_ON dsp56k_host_interface.icr |= DSP56K_ICR_TREQ
#define DSP56K_RX_INT_ON dsp56k_host_interface.icr |= DSP56K_ICR_RREQ
#define DSP56K_TX_INT_OFF dsp56k_host_interface.icr &= ~DSP56K_ICR_TREQ
#define DSP56K_RX_INT_OFF dsp56k_host_interface.icr &= ~DSP56K_ICR_RREQ
#define DSP56K_TRANSMIT (dsp56k_host_interface.isr & DSP56K_ISR_TXDE)
#define DSP56K_RECEIVE (dsp56k_host_interface.isr & DSP56K_ISR_RXDF)
#define handshake(count, maxio, timeout, ENABLE, f) \
{ \
long i, t, m; \
while (count > 0) { \
m = min_t(unsigned long, count, maxio); \
for (i = 0; i < m; i++) { \
for (t = 0; t < timeout && !ENABLE; t++) \
msleep(20); \
if(!ENABLE) \
return -EIO; \
f; \
} \
count -= m; \
if (m == maxio) msleep(20); \
} \
}
#define tx_wait(n) \
{ \
int t; \
for(t = 0; t < n && !DSP56K_TRANSMIT; t++) \
msleep(10); \
if(!DSP56K_TRANSMIT) { \
return -EIO; \
} \
}
#define rx_wait(n) \
{ \
int t; \
for(t = 0; t < n && !DSP56K_RECEIVE; t++) \
msleep(10); \
if(!DSP56K_RECEIVE) { \
return -EIO; \
} \
}
static DEFINE_MUTEX(dsp56k_mutex);
static struct dsp56k_device {
unsigned long in_use;
long maxio, timeout;
int tx_wsize, rx_wsize;
} dsp56k;
static struct class *dsp56k_class;
static int dsp56k_reset(void)
{
u_char status;
/* Power down the DSP */
sound_ym.rd_data_reg_sel = 14;
status = sound_ym.rd_data_reg_sel & 0xef;
sound_ym.wd_data = status;
sound_ym.wd_data = status | 0x10;
udelay(10);
/* Power up the DSP */
sound_ym.rd_data_reg_sel = 14;
sound_ym.wd_data = sound_ym.rd_data_reg_sel & 0xef;
return 0;
}
static int dsp56k_upload(u_char __user *bin, int len)
{
struct platform_device *pdev;
const struct firmware *fw;
const char fw_name[] = "dsp56k/bootstrap.bin";
int err;
int i;
dsp56k_reset();
pdev = platform_device_register_simple("dsp56k", 0, NULL, 0);
if (IS_ERR(pdev)) {
printk(KERN_ERR "Failed to register device for \"%s\"\n",
fw_name);
return -EINVAL;
}
err = request_firmware(&fw, fw_name, &pdev->dev);
platform_device_unregister(pdev);
if (err) {
printk(KERN_ERR "Failed to load image \"%s\" err %d\n",
fw_name, err);
return err;
}
if (fw->size % 3) {
printk(KERN_ERR "Bogus length %d in image \"%s\"\n",
fw->size, fw_name);
release_firmware(fw);
return -EINVAL;
}
for (i = 0; i < fw->size; i = i + 3) {
/* tx_wait(10); */
dsp56k_host_interface.data.b[1] = fw->data[i];
dsp56k_host_interface.data.b[2] = fw->data[i + 1];
dsp56k_host_interface.data.b[3] = fw->data[i + 2];
}
release_firmware(fw);
for (; i < 512; i++) {
/* tx_wait(10); */
dsp56k_host_interface.data.b[1] = 0;
dsp56k_host_interface.data.b[2] = 0;
dsp56k_host_interface.data.b[3] = 0;
}
for (i = 0; i < len; i++) {
tx_wait(10);
get_user(dsp56k_host_interface.data.b[1], bin++);
get_user(dsp56k_host_interface.data.b[2], bin++);
get_user(dsp56k_host_interface.data.b[3], bin++);
}
tx_wait(10);
dsp56k_host_interface.data.l = 3; /* Magic execute */
return 0;
}
static ssize_t dsp56k_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
struct inode *inode = file_inode(file);
int dev = iminor(inode) & 0x0f;
switch(dev)
{
case DSP56K_DEV_56001:
{
long n;
/* Don't do anything if nothing is to be done */
if (!count) return 0;
n = 0;
switch (dsp56k.rx_wsize) {
case 1: /* 8 bit */
{
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
put_user(dsp56k_host_interface.data.b[3], buf+n++));
return n;
}
case 2: /* 16 bit */
{
short __user *data;
count /= 2;
data = (short __user *) buf;
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
put_user(dsp56k_host_interface.data.w[1], data+n++));
return 2*n;
}
case 3: /* 24 bit */
{
count /= 3;
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
put_user(dsp56k_host_interface.data.b[1], buf+n++);
put_user(dsp56k_host_interface.data.b[2], buf+n++);
put_user(dsp56k_host_interface.data.b[3], buf+n++));
return 3*n;
}
case 4: /* 32 bit */
{
long __user *data;
count /= 4;
data = (long __user *) buf;
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
put_user(dsp56k_host_interface.data.l, data+n++));
return 4*n;
}
}
return -EFAULT;
}
default:
printk(KERN_ERR "DSP56k driver: Unknown minor device: %d\n", dev);
return -ENXIO;
}
}
static ssize_t dsp56k_write(struct file *file, const char __user *buf, size_t count,
loff_t *ppos)
{
struct inode *inode = file_inode(file);
int dev = iminor(inode) & 0x0f;
switch(dev)
{
case DSP56K_DEV_56001:
{
long n;
/* Don't do anything if nothing is to be done */
if (!count) return 0;
n = 0;
switch (dsp56k.tx_wsize) {
case 1: /* 8 bit */
{
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
get_user(dsp56k_host_interface.data.b[3], buf+n++));
return n;
}
case 2: /* 16 bit */
{
const short __user *data;
count /= 2;
data = (const short __user *)buf;
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
get_user(dsp56k_host_interface.data.w[1], data+n++));
return 2*n;
}
case 3: /* 24 bit */
{
count /= 3;
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
get_user(dsp56k_host_interface.data.b[1], buf+n++);
get_user(dsp56k_host_interface.data.b[2], buf+n++);
get_user(dsp56k_host_interface.data.b[3], buf+n++));
return 3*n;
}
case 4: /* 32 bit */
{
const long __user *data;
count /= 4;
data = (const long __user *)buf;
handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
get_user(dsp56k_host_interface.data.l, data+n++));
return 4*n;
}
}
return -EFAULT;
}
default:
printk(KERN_ERR "DSP56k driver: Unknown minor device: %d\n", dev);
return -ENXIO;
}
}
static long dsp56k_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int dev = iminor(file_inode(file)) & 0x0f;
void __user *argp = (void __user *)arg;
switch(dev)
{
case DSP56K_DEV_56001:
switch(cmd) {
case DSP56K_UPLOAD:
{
char __user *bin;
int r, len;
struct dsp56k_upload __user *binary = argp;
if(get_user(len, &binary->len) < 0)
return -EFAULT;
if(get_user(bin, &binary->bin) < 0)
return -EFAULT;
if (len <= 0) {
return -EINVAL; /* nothing to upload?!? */
}
if (len > DSP56K_MAX_BINARY_LENGTH) {
return -EINVAL;
}
mutex_lock(&dsp56k_mutex);
r = dsp56k_upload(bin, len);
mutex_unlock(&dsp56k_mutex);
if (r < 0) {
return r;
}
break;
}
case DSP56K_SET_TX_WSIZE:
if (arg > 4 || arg < 1)
return -EINVAL;
mutex_lock(&dsp56k_mutex);
dsp56k.tx_wsize = (int) arg;
mutex_unlock(&dsp56k_mutex);
break;
case DSP56K_SET_RX_WSIZE:
if (arg > 4 || arg < 1)
return -EINVAL;
mutex_lock(&dsp56k_mutex);
dsp56k.rx_wsize = (int) arg;
mutex_unlock(&dsp56k_mutex);
break;
case DSP56K_HOST_FLAGS:
{
int dir, out, status;
struct dsp56k_host_flags __user *hf = argp;
if(get_user(dir, &hf->dir) < 0)
return -EFAULT;
if(get_user(out, &hf->out) < 0)
return -EFAULT;
mutex_lock(&dsp56k_mutex);
if ((dir & 0x1) && (out & 0x1))
dsp56k_host_interface.icr |= DSP56K_ICR_HF0;
else if (dir & 0x1)
dsp56k_host_interface.icr &= ~DSP56K_ICR_HF0;
if ((dir & 0x2) && (out & 0x2))
dsp56k_host_interface.icr |= DSP56K_ICR_HF1;
else if (dir & 0x2)
dsp56k_host_interface.icr &= ~DSP56K_ICR_HF1;
status = 0;
if (dsp56k_host_interface.icr & DSP56K_ICR_HF0) status |= 0x1;
if (dsp56k_host_interface.icr & DSP56K_ICR_HF1) status |= 0x2;
if (dsp56k_host_interface.isr & DSP56K_ISR_HF2) status |= 0x4;
if (dsp56k_host_interface.isr & DSP56K_ISR_HF3) status |= 0x8;
mutex_unlock(&dsp56k_mutex);
return put_user(status, &hf->status);
}
case DSP56K_HOST_CMD:
if (arg > 31)
return -EINVAL;
mutex_lock(&dsp56k_mutex);
dsp56k_host_interface.cvr = (u_char)((arg & DSP56K_CVR_HV_MASK) |
DSP56K_CVR_HC);
mutex_unlock(&dsp56k_mutex);
break;
default:
return -EINVAL;
}
return 0;
default:
printk(KERN_ERR "DSP56k driver: Unknown minor device: %d\n", dev);
return -ENXIO;
}
}
/* As of 2.1.26 this should be dsp56k_poll,
* but how do I then check device minor number?
* Do I need this function at all???
*/
#if 0
static unsigned int dsp56k_poll(struct file *file, poll_table *wait)
{
int dev = iminor(file_inode(file)) & 0x0f;
switch(dev)
{
case DSP56K_DEV_56001:
/* poll_wait(file, ???, wait); */
return POLLIN | POLLRDNORM | POLLOUT;
default:
printk("DSP56k driver: Unknown minor device: %d\n", dev);
return 0;
}
}
#endif
static int dsp56k_open(struct inode *inode, struct file *file)
{
int dev = iminor(inode) & 0x0f;
int ret = 0;
mutex_lock(&dsp56k_mutex);
switch(dev)
{
case DSP56K_DEV_56001:
if (test_and_set_bit(0, &dsp56k.in_use)) {
ret = -EBUSY;
goto out;
}
dsp56k.timeout = TIMEOUT;
dsp56k.maxio = MAXIO;
dsp56k.rx_wsize = dsp56k.tx_wsize = 4;
DSP56K_TX_INT_OFF;
DSP56K_RX_INT_OFF;
/* Zero host flags */
dsp56k_host_interface.icr &= ~DSP56K_ICR_HF0;
dsp56k_host_interface.icr &= ~DSP56K_ICR_HF1;
break;
default:
ret = -ENODEV;
}
out:
mutex_unlock(&dsp56k_mutex);
return ret;
}
static int dsp56k_release(struct inode *inode, struct file *file)
{
int dev = iminor(inode) & 0x0f;
switch(dev)
{
case DSP56K_DEV_56001:
clear_bit(0, &dsp56k.in_use);
break;
default:
printk(KERN_ERR "DSP56k driver: Unknown minor device: %d\n", dev);
return -ENXIO;
}
return 0;
}
static const struct file_operations dsp56k_fops = {
.owner = THIS_MODULE,
.read = dsp56k_read,
.write = dsp56k_write,
.unlocked_ioctl = dsp56k_ioctl,
.open = dsp56k_open,
.release = dsp56k_release,
.llseek = noop_llseek,
};
/****** Init and module functions ******/
static char banner[] __initdata = KERN_INFO "DSP56k driver installed\n";
static int __init dsp56k_init_driver(void)
{
int err = 0;
if(!MACH_IS_ATARI || !ATARIHW_PRESENT(DSP56K)) {
printk("DSP56k driver: Hardware not present\n");
return -ENODEV;
}
if(register_chrdev(DSP56K_MAJOR, "dsp56k", &dsp56k_fops)) {
printk("DSP56k driver: Unable to register driver\n");
return -ENODEV;
}
dsp56k_class = class_create(THIS_MODULE, "dsp56k");
if (IS_ERR(dsp56k_class)) {
err = PTR_ERR(dsp56k_class);
goto out_chrdev;
}
device_create(dsp56k_class, NULL, MKDEV(DSP56K_MAJOR, 0), NULL,
"dsp56k");
printk(banner);
goto out;
out_chrdev:
unregister_chrdev(DSP56K_MAJOR, "dsp56k");
out:
return err;
}
module_init(dsp56k_init_driver);
static void __exit dsp56k_cleanup_driver(void)
{
device_destroy(dsp56k_class, MKDEV(DSP56K_MAJOR, 0));
class_destroy(dsp56k_class);
unregister_chrdev(DSP56K_MAJOR, "dsp56k");
}
module_exit(dsp56k_cleanup_driver);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("dsp56k/bootstrap.bin");