android_kernel_xiaomi_sm8350/drivers/usb/serial/console.c
Jason Wessel 06dd881f59 usb: fix null deferences in low level usb serial
The hw interface drivers for the usb serial devices deference the tty
structure to set up the parameters for the initial console.  The tty
structure should be passed as a parameter to the set_termios() call.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-08 15:37:07 -07:00

293 lines
6.6 KiB
C

/*
* USB Serial Console driver
*
* Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* Thanks to Randy Dunlap for the original version of this code.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/console.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
static int debug;
struct usbcons_info {
int magic;
int break_flag;
struct usb_serial_port *port;
};
static struct usbcons_info usbcons_info;
static struct console usbcons;
/*
* ------------------------------------------------------------
* USB Serial console driver
*
* Much of the code here is copied from drivers/char/serial.c
* and implements a phony serial console in the same way that
* serial.c does so that in case some software queries it,
* it will get the same results.
*
* Things that are different from the way the serial port code
* does things, is that we call the lower level usb-serial
* driver code to initialize the device, and we set the initial
* console speeds based on the command line arguments.
* ------------------------------------------------------------
*/
/*
* The parsing of the command line works exactly like the
* serial.c code, except that the specifier is "ttyUSB" instead
* of "ttyS".
*/
static int usb_console_setup(struct console *co, char *options)
{
struct usbcons_info *info = &usbcons_info;
int baud = 9600;
int bits = 8;
int parity = 'n';
int doflow = 0;
int cflag = CREAD | HUPCL | CLOCAL;
char *s;
struct usb_serial *serial;
struct usb_serial_port *port;
int retval = 0;
struct tty_struct *tty = NULL;
struct ktermios *termios = NULL, dummy;
dbg("%s", __func__);
if (options) {
baud = simple_strtoul(options, NULL, 10);
s = options;
while (*s >= '0' && *s <= '9')
s++;
if (*s)
parity = *s++;
if (*s)
bits = *s++ - '0';
if (*s)
doflow = (*s++ == 'r');
}
/* Sane default */
if (baud == 0)
baud = 9600;
switch (bits) {
case 7:
cflag |= CS7;
break;
default:
case 8:
cflag |= CS8;
break;
}
switch (parity) {
case 'o': case 'O':
cflag |= PARODD;
break;
case 'e': case 'E':
cflag |= PARENB;
break;
}
co->cflag = cflag;
/*
* no need to check the index here: if the index is wrong, console
* code won't call us
*/
serial = usb_serial_get_by_index(co->index);
if (serial == NULL) {
/* no device is connected yet, sorry :( */
err("No USB device connected to ttyUSB%i", co->index);
return -ENODEV;
}
port = serial->port[0];
port->port.tty = NULL;
info->port = port;
++port->port.count;
if (port->port.count == 1) {
if (serial->type->set_termios) {
/*
* allocate a fake tty so the driver can initialize
* the termios structure, then later call set_termios to
* configure according to command line arguments
*/
tty = kzalloc(sizeof(*tty), GFP_KERNEL);
if (!tty) {
retval = -ENOMEM;
err("no more memory");
goto reset_open_count;
}
termios = kzalloc(sizeof(*termios), GFP_KERNEL);
if (!termios) {
retval = -ENOMEM;
err("no more memory");
goto free_tty;
}
memset(&dummy, 0, sizeof(struct ktermios));
tty->termios = termios;
port->port.tty = tty;
}
/* only call the device specific open if this
* is the first time the port is opened */
if (serial->type->open)
retval = serial->type->open(NULL, port, NULL);
else
retval = usb_serial_generic_open(NULL, port, NULL);
if (retval) {
err("could not open USB console port");
goto free_termios;
}
if (serial->type->set_termios) {
termios->c_cflag = cflag;
tty_termios_encode_baud_rate(termios, baud, baud);
serial->type->set_termios(tty, port, &dummy);
port->port.tty = NULL;
kfree(termios);
kfree(tty);
}
}
port->console = 1;
retval = 0;
out:
return retval;
free_termios:
kfree(termios);
port->port.tty = NULL;
free_tty:
kfree(tty);
reset_open_count:
port->port.count = 0;
goto out;
}
static void usb_console_write(struct console *co,
const char *buf, unsigned count)
{
static struct usbcons_info *info = &usbcons_info;
struct usb_serial_port *port = info->port;
struct usb_serial *serial;
int retval = -ENODEV;
if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
return;
serial = port->serial;
if (count == 0)
return;
dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
if (!port->port.count) {
dbg("%s - port not opened", __func__);
return;
}
while (count) {
unsigned int i;
unsigned int lf;
/* search for LF so we can insert CR if necessary */
for (i = 0, lf = 0 ; i < count ; i++) {
if (*(buf + i) == 10) {
lf = 1;
i++;
break;
}
}
/* pass on to the driver specific version of this function if
it is available */
if (serial->type->write)
retval = serial->type->write(NULL, port, buf, i);
else
retval = usb_serial_generic_write(NULL, port, buf, i);
dbg("%s - return value : %d", __func__, retval);
if (lf) {
/* append CR after LF */
unsigned char cr = 13;
if (serial->type->write)
retval = serial->type->write(NULL,
port, &cr, 1);
else
retval = usb_serial_generic_write(NULL,
port, &cr, 1);
dbg("%s - return value : %d", __func__, retval);
}
buf += i;
count -= i;
}
}
static struct console usbcons = {
.name = "ttyUSB",
.write = usb_console_write,
.setup = usb_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
void usb_serial_console_disconnect(struct usb_serial *serial)
{
if (serial && serial->port && serial->port[0]
&& serial->port[0] == usbcons_info.port) {
usb_serial_console_exit();
usb_serial_put(serial);
}
}
void usb_serial_console_init(int serial_debug, int minor)
{
debug = serial_debug;
if (minor == 0) {
/*
* Call register_console() if this is the first device plugged
* in. If we call it earlier, then the callback to
* console_setup() will fail, as there is not a device seen by
* the USB subsystem yet.
*/
/*
* Register console.
* NOTES:
* console_setup() is called (back) immediately (from
* register_console). console_write() is called immediately
* from register_console iff CON_PRINTBUFFER is set in flags.
*/
dbg("registering the USB serial console.");
register_console(&usbcons);
}
}
void usb_serial_console_exit(void)
{
if (usbcons_info.port) {
unregister_console(&usbcons);
if (usbcons_info.port->port.count)
usbcons_info.port->port.count--;
usbcons_info.port = NULL;
}
}