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linux-next/include/linux/usb/serial.h
Aristeu Rozanski 9a6b1efa6f USB: usb_serial: clean tty reference in the last close 
When a usb serial adapter is used as console, the usb serial console
driver bumps the open_count on the port struct used but doesn't attach
a real tty to it (only a fake one temporaly). If this port is opened later
using the regular character device interface, the open method won't
initialize the port, which is the expected, and will receive a brand new
tty struct created by tty layer, which will be stored in port->tty.

When the last close is issued, open_count won't be 0 because of the
console usage and the port->tty will still contain the old tty value. This
is the last ttyUSB<n> close so the allocated tty will be freed by the
tty layer. The usb_serial and usb_serial_port are still in use by the
console, so port_free() won't be called (serial_close() ->
usb_serial_put() -> destroy_serial() -> port_free()), so the scheduled
work (port->work, usb_serial_port_work()) will still run. And
usb_serial_port_work() does:
(...)
        tty = port->tty;
        if (!tty)
                return;

        tty_wakeup(tty);
which causes (manually copied):

Faulting instruction address: 0x6b6b6b68
Oops: Kernel access of bad area, sig: 11 [#1]
PREEMPT PowerMac
Modules linked in: binfmt_misc ipv6 nfs lockd nfs_acl sunrpc dm_snapshot dm_mirror dm_mod hfsplus uinput ams input_polldev genrtc cpufreq_powersave i2c_powermac therm_adt746x snd_aoa_codec_tas snd_aoa_fabric_layout snd_aoa joydev snd_aoa_i2sbus snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_page_alloc pmac_zilog serial_core evdev ide_cd cdrom snd appletouch soundcore snd_aoa_soundbus bcm43xx firmware_class usbhid ieee80211softmac ff_memless firewire_ohci firewire_core ieee80211 ieee80211_crypt crc_itu_t sungem sungem_phy uninorth_agp agpart ssb
NIP: 6b6b6b68 LR: c01b2108 CTR: 6b6b6b6b
REGS: c106de80 TRAP: 0400   Not tainted  (2.6.24-rc2)
MSR: 40009032 <EE,ME,IR,DR>  CR: 82004024  XER: 00000000
TASK = c106b4c0[5] 'events/0' THREAD: c106c000
GPR00: 6b6b6b6b c106df30 c106b4c0 c2d613a0 00009032 00000001 00001a00 00000001
GPR08: 00000008 00000000 00000000 c106c000 42004028 00000000 016ffbe0 0171a724
GPR16: 016ffcf4 00240e24 00240e70 016fee68 016ff9a4 c03046c4 c0327f50 c03046fc
GPR24: c106b6b9 c106b4c0 c101d610 c106c000 c02160fc c1eac1dc c2d613ac c2d613a0
NIP [6b6b6b68] 0x6b6b6b68
LR [c01b2108] tty_wakeup+0x6c/0x9c
Call Trace:
[c106df30] [c01b20e8] tty_wakeup+0x4c/0x9c (unreliable)
[c106df40] [c0216138] usb_serial_port_work+0x3c/0x78
[c106df50] [c00432e8] run_workqueue+0xc4/0x15c
[c106df90] [c0043798] worker_thread+0xa0/0x124
[c106dfd0] [c0048224] kthread+0x48/0x84
[c106dff0] [c00129bc] kernel_thread+0x44/0x60
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
Slab corruption: size-2048 start=c2d613a0, len=2048
Redzone: 0x9f911029d74e35b/0x9f911029d74e35b.
Last user: [<c01b16d8>](release_one_tty+0xbc/0xf4)
050: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
Prev obj: start=c2d60b88, len=2048
Redzone: 0x9f911029d74e35b/0x9f911029d74e35b.
Last user: [<c00f30ec>](show_stat+0x410/0x428)
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b

This patch avoids this, clearing port->tty considering if the port is
used as serial console or not

Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01 14:34:50 -08:00

326 lines
13 KiB
C
Raw Blame History

/*
* USB Serial Converter stuff
*
* Copyright (C) 1999 - 2005
* 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 as published by
* the Free Software Foundation; version 2 of the License.
*
*/
#ifndef __LINUX_USB_SERIAL_H
#define __LINUX_USB_SERIAL_H
#include <linux/kref.h>
#include <linux/mutex.h>
#define SERIAL_TTY_MAJOR 188 /* Nice legal number now */
#define SERIAL_TTY_MINORS 255 /* loads of devices :) */
#define MAX_NUM_PORTS 8 /* The maximum number of ports one device can grab at once */
/* parity check flag */
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
/**
* usb_serial_port: structure for the specific ports of a device.
* @serial: pointer back to the struct usb_serial owner of this port.
* @tty: pointer to the corresponding tty for this port.
* @lock: spinlock to grab when updating portions of this structure.
* @mutex: mutex used to synchronize serial_open() and serial_close()
* access for this port.
* @number: the number of the port (the minor number).
* @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
* @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
* @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
* for this port.
* @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
* @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
* @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
* @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
* for this port.
* @bulk_in_buffer: pointer to the bulk in buffer for this port.
* @read_urb: pointer to the bulk in struct urb for this port.
* @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
* port.
* @bulk_out_buffer: pointer to the bulk out buffer for this port.
* @bulk_out_size: the size of the bulk_out_buffer, in bytes.
* @write_urb: pointer to the bulk out struct urb for this port.
* @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
* port.
* @write_wait: a wait_queue_head_t used by the port.
* @work: work queue entry for the line discipline waking up.
* @open_count: number of times this port has been opened.
* @throttled: nonzero if the read urb is inactive to throttle the device
* @throttle_req: nonzero if the tty wants to throttle us
*
* This structure is used by the usb-serial core and drivers for the specific
* ports of a device.
*/
struct usb_serial_port {
struct usb_serial * serial;
struct tty_struct * tty;
spinlock_t lock;
struct mutex mutex;
unsigned char number;
unsigned char * interrupt_in_buffer;
struct urb * interrupt_in_urb;
__u8 interrupt_in_endpointAddress;
unsigned char * interrupt_out_buffer;
int interrupt_out_size;
struct urb * interrupt_out_urb;
__u8 interrupt_out_endpointAddress;
unsigned char * bulk_in_buffer;
int bulk_in_size;
struct urb * read_urb;
__u8 bulk_in_endpointAddress;
unsigned char * bulk_out_buffer;
int bulk_out_size;
struct urb * write_urb;
int write_urb_busy;
__u8 bulk_out_endpointAddress;
wait_queue_head_t write_wait;
struct work_struct work;
int open_count;
char throttled;
char throttle_req;
char console;
struct device dev;
};
#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
/* get and set the port private data pointer helper functions */
static inline void *usb_get_serial_port_data (struct usb_serial_port *port)
{
return dev_get_drvdata(&port->dev);
}
static inline void usb_set_serial_port_data (struct usb_serial_port *port, void *data)
{
dev_set_drvdata(&port->dev, data);
}
/**
* usb_serial - structure used by the usb-serial core for a device
* @dev: pointer to the struct usb_device for this device
* @type: pointer to the struct usb_serial_driver for this device
* @interface: pointer to the struct usb_interface for this device
* @minor: the starting minor number for this device
* @num_ports: the number of ports this device has
* @num_interrupt_in: number of interrupt in endpoints we have
* @num_interrupt_out: number of interrupt out endpoints we have
* @num_bulk_in: number of bulk in endpoints we have
* @num_bulk_out: number of bulk out endpoints we have
* @port: array of struct usb_serial_port structures for the different ports.
* @private: place to put any driver specific information that is needed. The
* usb-serial driver is required to manage this data, the usb-serial core
* will not touch this. Use usb_get_serial_data() and
* usb_set_serial_data() to access this.
*/
struct usb_serial {
struct usb_device * dev;
struct usb_serial_driver * type;
struct usb_interface * interface;
unsigned char minor;
unsigned char num_ports;
unsigned char num_port_pointers;
char num_interrupt_in;
char num_interrupt_out;
char num_bulk_in;
char num_bulk_out;
struct usb_serial_port * port[MAX_NUM_PORTS];
struct kref kref;
void * private;
};
#define to_usb_serial(d) container_of(d, struct usb_serial, kref)
#define NUM_DONT_CARE 99
/* get and set the serial private data pointer helper functions */
static inline void *usb_get_serial_data (struct usb_serial *serial)
{
return serial->private;
}
static inline void usb_set_serial_data (struct usb_serial *serial, void *data)
{
serial->private = data;
}
/**
* usb_serial_driver - describes a usb serial driver
* @description: pointer to a string that describes this driver. This string used
* in the syslog messages when a device is inserted or removed.
* @id_table: pointer to a list of usb_device_id structures that define all
* of the devices this structure can support.
* @num_interrupt_in: If a device doesn't have this many interrupt-in
* endpoints, it won't be sent to the driver's attach() method.
* (But it might still be sent to the probe() method.)
* @num_interrupt_out: If a device doesn't have this many interrupt-out
* endpoints, it won't be sent to the driver's attach() method.
* (But it might still be sent to the probe() method.)
* @num_bulk_in: If a device doesn't have this many bulk-in
* endpoints, it won't be sent to the driver's attach() method.
* (But it might still be sent to the probe() method.)
* @num_bulk_out: If a device doesn't have this many bulk-out
* endpoints, it won't be sent to the driver's attach() method.
* (But it might still be sent to the probe() method.)
* @num_ports: the number of different ports this device will have.
* @calc_num_ports: pointer to a function to determine how many ports this
* device has dynamically. It will be called after the probe()
* callback is called, but before attach()
* @probe: pointer to the driver's probe function.
* This will be called when the device is inserted into the system,
* but before the device has been fully initialized by the usb_serial
* subsystem. Use this function to download any firmware to the device,
* or any other early initialization that might be needed.
* Return 0 to continue on with the initialization sequence. Anything
* else will abort it.
* @attach: pointer to the driver's attach function.
* This will be called when the struct usb_serial structure is fully set
* set up. Do any local initialization of the device, or any private
* memory structure allocation at this point in time.
* @shutdown: pointer to the driver's shutdown function. This will be
* called when the device is removed from the system.
* @usb_driver: pointer to the struct usb_driver that controls this
* device. This is necessary to allow dynamic ids to be added to
* the driver from sysfs.
*
* This structure is defines a USB Serial driver. It provides all of
* the information that the USB serial core code needs. If the function
* pointers are defined, then the USB serial core code will call them when
* the corresponding tty port functions are called. If they are not
* called, the generic serial function will be used instead.
*
* The driver.owner field should be set to the module owner of this driver.
* The driver.name field should be set to the name of this driver (remember
* it will show up in sysfs, so it needs to be short and to the point.
* Useing the module name is a good idea.)
*/
struct usb_serial_driver {
const char *description;
const struct usb_device_id *id_table;
char num_interrupt_in;
char num_interrupt_out;
char num_bulk_in;
char num_bulk_out;
char num_ports;
struct list_head driver_list;
struct device_driver driver;
struct usb_driver *usb_driver;
struct usb_dynids dynids;
int (*probe) (struct usb_serial *serial, const struct usb_device_id *id);
int (*attach) (struct usb_serial *serial);
int (*calc_num_ports) (struct usb_serial *serial);
void (*shutdown) (struct usb_serial *serial);
int (*port_probe) (struct usb_serial_port *port);
int (*port_remove) (struct usb_serial_port *port);
int (*suspend) (struct usb_serial *serial, pm_message_t message);
int (*resume) (struct usb_serial *serial);
/* serial function calls */
int (*open) (struct usb_serial_port *port, struct file * filp);
void (*close) (struct usb_serial_port *port, struct file * filp);
int (*write) (struct usb_serial_port *port, const unsigned char *buf, int count);
int (*write_room) (struct usb_serial_port *port);
int (*ioctl) (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
void (*set_termios) (struct usb_serial_port *port, struct ktermios * old);
void (*break_ctl) (struct usb_serial_port *port, int break_state);
int (*chars_in_buffer) (struct usb_serial_port *port);
void (*throttle) (struct usb_serial_port *port);
void (*unthrottle) (struct usb_serial_port *port);
int (*tiocmget) (struct usb_serial_port *port, struct file *file);
int (*tiocmset) (struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
void (*read_int_callback)(struct urb *urb);
void (*write_int_callback)(struct urb *urb);
void (*read_bulk_callback)(struct urb *urb);
void (*write_bulk_callback)(struct urb *urb);
};
#define to_usb_serial_driver(d) container_of(d, struct usb_serial_driver, driver)
extern int usb_serial_register(struct usb_serial_driver *driver);
extern void usb_serial_deregister(struct usb_serial_driver *driver);
extern void usb_serial_port_softint(struct usb_serial_port *port);
extern int usb_serial_probe(struct usb_interface *iface, const struct usb_device_id *id);
extern void usb_serial_disconnect(struct usb_interface *iface);
extern int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
extern int usb_serial_resume(struct usb_interface *intf);
extern int ezusb_writememory (struct usb_serial *serial, int address, unsigned char *data, int length, __u8 bRequest);
extern int ezusb_set_reset (struct usb_serial *serial, unsigned char reset_bit);
/* USB Serial console functions */
#ifdef CONFIG_USB_SERIAL_CONSOLE
extern void usb_serial_console_init (int debug, int minor);
extern void usb_serial_console_exit (void);
extern void usb_serial_console_disconnect(struct usb_serial *serial);
#else
static inline void usb_serial_console_init (int debug, int minor) { }
static inline void usb_serial_console_exit (void) { }
static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
#endif
/* Functions needed by other parts of the usbserial core */
extern struct usb_serial *usb_serial_get_by_index (unsigned int minor);
extern void usb_serial_put(struct usb_serial *serial);
extern int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp);
extern int usb_serial_generic_write (struct usb_serial_port *port, const unsigned char *buf, int count);
extern void usb_serial_generic_close (struct usb_serial_port *port, struct file *filp);
extern int usb_serial_generic_resume (struct usb_serial *serial);
extern int usb_serial_generic_write_room (struct usb_serial_port *port);
extern int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port);
extern void usb_serial_generic_read_bulk_callback (struct urb *urb);
extern void usb_serial_generic_write_bulk_callback (struct urb *urb);
extern void usb_serial_generic_throttle (struct usb_serial_port *port);
extern void usb_serial_generic_unthrottle (struct usb_serial_port *port);
extern void usb_serial_generic_shutdown (struct usb_serial *serial);
extern int usb_serial_generic_register (int debug);
extern void usb_serial_generic_deregister (void);
extern int usb_serial_bus_register (struct usb_serial_driver *device);
extern void usb_serial_bus_deregister (struct usb_serial_driver *device);
extern struct usb_serial_driver usb_serial_generic_device;
extern struct bus_type usb_serial_bus_type;
extern struct tty_driver *usb_serial_tty_driver;
static inline void usb_serial_debug_data(int debug,
struct device *dev,
const char *function, int size,
const unsigned char *data)
{
int i;
if (debug) {
dev_printk(KERN_DEBUG, dev, "%s - length = %d, data = ", function, size);
for (i = 0; i < size; ++i)
printk ("%.2x ", data[i]);
printk ("\n");
}
}
/* Use our own dbg macro */
#undef dbg
#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG "%s: " format "\n" , __FILE__ , ## arg); } while (0)
#endif /* ifdef __LINUX_USB_SERIAL_H */
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