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linux-next/drivers/hid/hid-picolcd_cir.c
Bruno Prémont 1cde501bb4 HID: picolcd: Prevent NULL pointer dereference on _remove()
When picolcd is switched into bootloader mode (for FW flashing) make
sure not to try to dereference NULL-pointers of feature-devices during
unplug/unbind.

This fixes following BUG:
  BUG: unable to handle kernel NULL pointer dereference at 00000298
  IP: [<f811f56b>] picolcd_exit_framebuffer+0x1b/0x80 [hid_picolcd]
  *pde = 00000000
  Oops: 0000 [#1]
  Modules linked in: hid_picolcd syscopyarea sysfillrect sysimgblt fb_sys_fops
  CPU: 0 PID: 15 Comm: khubd Not tainted 3.11.0-rc7-00002-g50d62d4 #2
  EIP: 0060:[<f811f56b>] EFLAGS: 00010292 CPU: 0
  EIP is at picolcd_exit_framebuffer+0x1b/0x80 [hid_picolcd]
  Call Trace:
   [<f811d1ab>] picolcd_remove+0xcb/0x120 [hid_picolcd]
   [<c1469b09>] hid_device_remove+0x59/0xc0
   [<c13464ca>] __device_release_driver+0x5a/0xb0
   [<c134653f>] device_release_driver+0x1f/0x30
   [<c134603d>] bus_remove_device+0x9d/0xd0
   [<c13439a5>] device_del+0xd5/0x150
   [<c14696a4>] hid_destroy_device+0x24/0x60
   [<c1474cbb>] usbhid_disconnect+0x1b/0x40
   ...

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Cc: stable@kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-09-02 13:36:50 +02:00

152 lines
4.7 KiB
C

/***************************************************************************
* Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *
* *
* Based on Logitech G13 driver (v0.4) *
* Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *
* *
* 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. *
* *
* This driver is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this software. If not see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#include <linux/hid.h>
#include <linux/hid-debug.h>
#include <linux/input.h>
#include "hid-ids.h"
#include <linux/fb.h>
#include <linux/vmalloc.h>
#include <linux/backlight.h>
#include <linux/lcd.h>
#include <linux/leds.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/completion.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <media/rc-core.h>
#include "hid-picolcd.h"
int picolcd_raw_cir(struct picolcd_data *data,
struct hid_report *report, u8 *raw_data, int size)
{
unsigned long flags;
int i, w, sz;
DEFINE_IR_RAW_EVENT(rawir);
/* ignore if rc_dev is NULL or status is shunned */
spin_lock_irqsave(&data->lock, flags);
if (!data->rc_dev || (data->status & PICOLCD_CIR_SHUN)) {
spin_unlock_irqrestore(&data->lock, flags);
return 1;
}
spin_unlock_irqrestore(&data->lock, flags);
/* PicoLCD USB packets contain 16-bit intervals in network order,
* with value negated for pulse. Intervals are in microseconds.
*
* Note: some userspace LIRC code for PicoLCD says negated values
* for space - is it a matter of IR chip? (pulse for my TSOP2236)
*
* In addition, the first interval seems to be around 15000 + base
* interval for non-first report of IR data - thus the quirk below
* to get RC_CODE to understand Sony and JVC remotes I have at hand
*/
sz = size > 0 ? min((int)raw_data[0], size-1) : 0;
for (i = 0; i+1 < sz; i += 2) {
init_ir_raw_event(&rawir);
w = (raw_data[i] << 8) | (raw_data[i+1]);
rawir.pulse = !!(w & 0x8000);
rawir.duration = US_TO_NS(rawir.pulse ? (65536 - w) : w);
/* Quirk!! - see above */
if (i == 0 && rawir.duration > 15000000)
rawir.duration -= 15000000;
ir_raw_event_store(data->rc_dev, &rawir);
}
ir_raw_event_handle(data->rc_dev);
return 1;
}
static int picolcd_cir_open(struct rc_dev *dev)
{
struct picolcd_data *data = dev->priv;
unsigned long flags;
spin_lock_irqsave(&data->lock, flags);
data->status &= ~PICOLCD_CIR_SHUN;
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static void picolcd_cir_close(struct rc_dev *dev)
{
struct picolcd_data *data = dev->priv;
unsigned long flags;
spin_lock_irqsave(&data->lock, flags);
data->status |= PICOLCD_CIR_SHUN;
spin_unlock_irqrestore(&data->lock, flags);
}
/* initialize CIR input device */
int picolcd_init_cir(struct picolcd_data *data, struct hid_report *report)
{
struct rc_dev *rdev;
int ret = 0;
rdev = rc_allocate_device();
if (!rdev)
return -ENOMEM;
rdev->priv = data;
rdev->driver_type = RC_DRIVER_IR_RAW;
rdev->allowed_protos = RC_BIT_ALL;
rdev->open = picolcd_cir_open;
rdev->close = picolcd_cir_close;
rdev->input_name = data->hdev->name;
rdev->input_phys = data->hdev->phys;
rdev->input_id.bustype = data->hdev->bus;
rdev->input_id.vendor = data->hdev->vendor;
rdev->input_id.product = data->hdev->product;
rdev->input_id.version = data->hdev->version;
rdev->dev.parent = &data->hdev->dev;
rdev->driver_name = PICOLCD_NAME;
rdev->map_name = RC_MAP_RC6_MCE;
rdev->timeout = MS_TO_NS(100);
rdev->rx_resolution = US_TO_NS(1);
ret = rc_register_device(rdev);
if (ret)
goto err;
data->rc_dev = rdev;
return 0;
err:
rc_free_device(rdev);
return ret;
}
void picolcd_exit_cir(struct picolcd_data *data)
{
struct rc_dev *rdev = data->rc_dev;
data->rc_dev = NULL;
if (rdev)
rc_unregister_device(rdev);
}