Re: [PATCH] fujitsu-laptop: consolidated fixes (NULL pointer checks, [un]registration fixes, etc)

From: Jonathan Woithe
Date: Thu Jul 30 2009 - 03:56:03 EST

Hi all

This patch consolidates the two patches posted by Bartlomiej Zolnierkiewicz
and the NULL pointer patch which came out of a discussion with Julia Lawall.
Some additional NULL pointer check tidy-ups have also been done.

To summarise:

* Take care of the following entries from Dan's list:

drivers/platform/x86/fujitsu-laptop.c +327 set_lcd_level(13) warning:
variable derefenced before check 'fujitsu'
drivers/platform/x86/fujitsu-laptop.c +358 set_lcd_level_alt(13) warning:
variable derefenced before check 'fujitsu'

* Move led_classdev_unregister() calls from fujitsu_cleanup() to
acpi_fujitsu_hotkey_remove().

* Fix ordering in fujitsu_cleanup().

* Fix backlight_device_register() failure handling in fujitsu_init().

* Add missing sysfs group removal on failure to fujitsu_init().

* Add input device unregistering on failure to acpi_fujitsu_add()
and acpi_fujitsu_hotkey_add().

* Add input device unregistering/freeing to acpi_fujitsu_remove()
and acpi_fujitsu_hotkey_remove() (also remove superfluous 'device'
and 'acpi_driver_data(device)' checks while at it).

* Do few minor cleanups.

* Fix some additional NULL pointer checks which should occur before the
initial dereference.

Patch is relative to linux-acpi-2.6.git head.


Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Cc: corbet@xxxxxxx
Cc: eteo@xxxxxxxxxx
Cc: Julia Lawall <julia@xxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Signed-off-by: Jonathan Woithe <jwoithe@xxxxxxxxxxxxxxxxxxxxxxx>

--- a/drivers/platform/x86/fujitsu-laptop.c 2009-07-30 16:30:55.455795000 +0930
+++ b/drivers/platform/x86/fujitsu-laptop.c 2009-07-30 16:48:45.542784340 +0930
@@ -70,7 +70,7 @@
#include <linux/leds.h>
#endif

-#define FUJITSU_DRIVER_VERSION "0.5.0"
+#define FUJITSU_DRIVER_VERSION "0.6.0"

#define FUJITSU_LCD_N_LEVELS 8

@@ -321,10 +321,7 @@ static int set_lcd_level(int level)
vdbg_printk(FUJLAPTOP_DBG_TRACE, "set lcd level via SBLL [%d]\n",
level);

- if (level < 0 || level >= fujitsu->max_brightness)
- return -EINVAL;
-
- if (!fujitsu)
+ if (!fujitsu || level < 0 || level >= fujitsu->max_brightness)
return -EINVAL;

status = acpi_get_handle(fujitsu->acpi_handle, "SBLL", &handle);
@@ -352,10 +349,7 @@ static int set_lcd_level_alt(int level)
vdbg_printk(FUJLAPTOP_DBG_TRACE, "set lcd level via SBL2 [%d]\n",
level);

- if (level < 0 || level >= fujitsu->max_brightness)
- return -EINVAL;
-
- if (!fujitsu)
+ if (!fujitsu || level < 0 || level >= fujitsu->max_brightness)
return -EINVAL;

status = acpi_get_handle(fujitsu->acpi_handle, "SBL2", &handle);
@@ -697,7 +691,7 @@ static int acpi_fujitsu_add(struct acpi_
result = acpi_bus_get_power(fujitsu->acpi_handle, &state);
if (result) {
printk(KERN_ERR "Error reading power state\n");
- goto end;
+ goto err_unregister_input_dev;
}

printk(KERN_INFO PREFIX "%s [%s] (%s)\n",
@@ -728,25 +722,31 @@ static int acpi_fujitsu_add(struct acpi_

return result;

-end:
+err_unregister_input_dev:
+ input_unregister_device(input);
err_free_input_dev:
input_free_device(input);
err_stop:
-
return result;
}

static int acpi_fujitsu_remove(struct acpi_device *device, int type)
{
struct fujitsu_t *fujitsu = NULL;
+ struct input_dev *input = NULL;

- if (!device || !acpi_driver_data(device))
+ if (!device)
return -EINVAL;

- fujitsu = acpi_driver_data(device);
-
- if (!device || !acpi_driver_data(device))
- return -EINVAL;
+ fujitsu = acpi_driver_data(device);
+ if (!fujitsu)
+ return -EINVAL;
+ input = fujitsu->input;
+
+ if (input) {
+ input_unregister_device(input);
+ input_free_device(input);
+ }

fujitsu->acpi_handle = NULL;

@@ -871,7 +871,7 @@ static int acpi_fujitsu_hotkey_add(struc
result = acpi_bus_get_power(fujitsu_hotkey->acpi_handle, &state);
if (result) {
printk(KERN_ERR "Error reading power state\n");
- goto end;
+ goto err_unregister_input_dev;
}

printk(KERN_INFO PREFIX "%s [%s] (%s)\n",
@@ -911,7 +911,7 @@ static int acpi_fujitsu_hotkey_add(struc
printk(KERN_INFO "fujitsu-laptop: BTNI: [0x%x]\n",
call_fext_func(FUNC_BUTTONS, 0x0, 0x0, 0x0));

- #ifdef CONFIG_LEDS_CLASS
+#ifdef CONFIG_LEDS_CLASS
if (call_fext_func(FUNC_LEDS, 0x0, 0x0, 0x0) & LOGOLAMP_POWERON) {
result = led_classdev_register(&fujitsu->pf_device->dev,
&logolamp_led);
@@ -934,33 +934,50 @@ static int acpi_fujitsu_hotkey_add(struc
"LED handler for keyboard lamps, error %i\n", result);
}
}
- #endif
+#endif

return result;

-end:
+err_unregister_input_dev:
+ input_unregister_device(input);
err_free_input_dev:
input_free_device(input);
err_free_fifo:
kfifo_free(fujitsu_hotkey->fifo);
err_stop:
-
return result;
}

static int acpi_fujitsu_hotkey_remove(struct acpi_device *device, int type)
{
struct fujitsu_hotkey_t *fujitsu_hotkey = NULL;
+ struct input_dev *input = NULL;

- if (!device || !acpi_driver_data(device))
+ if (!device)
return -EINVAL;
-
fujitsu_hotkey = acpi_driver_data(device);
+ if (!fujitsu_hotkey)
+ return -EINVAL;

- fujitsu_hotkey->acpi_handle = NULL;
+ input = fujitsu_hotkey->input;
+
+#ifdef CONFIG_LEDS_CLASS
+ if (fujitsu_hotkey->logolamp_registered)
+ led_classdev_unregister(&logolamp_led);
+
+ if (fujitsu_hotkey->kblamps_registered)
+ led_classdev_unregister(&kblamps_led);
+#endif
+
+ if (input) {
+ input_unregister_device(input);
+ input_free_device(input);
+ }

kfifo_free(fujitsu_hotkey->fifo);

+ fujitsu_hotkey->acpi_handle = NULL;
+
return 0;
}

@@ -1130,8 +1147,11 @@ static int __init fujitsu_init(void)
fujitsu->bl_device =
backlight_device_register("fujitsu-laptop", NULL, NULL,
&fujitsubl_ops);
- if (IS_ERR(fujitsu->bl_device))
- return PTR_ERR(fujitsu->bl_device);
+ if (IS_ERR(fujitsu->bl_device)) {
+ ret = PTR_ERR(fujitsu->bl_device);
+ fujitsu->bl_device = NULL;
+ goto fail_sysfs_group;
+ }
max_brightness = fujitsu->max_brightness;
fujitsu->bl_device->props.max_brightness = max_brightness - 1;
fujitsu->bl_device->props.brightness = fujitsu->brightness_level;
@@ -1171,32 +1191,22 @@ static int __init fujitsu_init(void)
return 0;

fail_hotkey1:
-
kfree(fujitsu_hotkey);
-
fail_hotkey:
-
platform_driver_unregister(&fujitsupf_driver);
-
fail_backlight:
-
if (fujitsu->bl_device)
backlight_device_unregister(fujitsu->bl_device);
-
+fail_sysfs_group:
+ sysfs_remove_group(&fujitsu->pf_device->dev.kobj,
+ &fujitsupf_attribute_group);
fail_platform_device2:
-
platform_device_del(fujitsu->pf_device);
-
fail_platform_device1:
-
platform_device_put(fujitsu->pf_device);
-
fail_platform_driver:
-
acpi_bus_unregister_driver(&acpi_fujitsu_driver);
-
fail_acpi:
-
kfree(fujitsu);

return ret;
@@ -1204,28 +1214,23 @@ fail_acpi:

static void __exit fujitsu_cleanup(void)
{
- #ifdef CONFIG_LEDS_CLASS
- if (fujitsu_hotkey->logolamp_registered != 0)
- led_classdev_unregister(&logolamp_led);
+ acpi_bus_unregister_driver(&acpi_fujitsu_hotkey_driver);

- if (fujitsu_hotkey->kblamps_registered != 0)
- led_classdev_unregister(&kblamps_led);
- #endif
+ kfree(fujitsu_hotkey);

- sysfs_remove_group(&fujitsu->pf_device->dev.kobj,
- &fujitsupf_attribute_group);
- platform_device_unregister(fujitsu->pf_device);
platform_driver_unregister(&fujitsupf_driver);
+
if (fujitsu->bl_device)
backlight_device_unregister(fujitsu->bl_device);

- acpi_bus_unregister_driver(&acpi_fujitsu_driver);
+ sysfs_remove_group(&fujitsu->pf_device->dev.kobj,
+ &fujitsupf_attribute_group);

- kfree(fujitsu);
+ platform_device_unregister(fujitsu->pf_device);

- acpi_bus_unregister_driver(&acpi_fujitsu_hotkey_driver);
+ acpi_bus_unregister_driver(&acpi_fujitsu_driver);

- kfree(fujitsu_hotkey);
+ kfree(fujitsu);

printk(KERN_INFO "fujitsu-laptop: driver unloaded.\n");
}
--
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