Re: Linux 2.6.27.16

[David Engel <david@istwok.net>]

On Thu, Feb 12, 2009 at 10:04:48AM -0800, Greg KH wrote:
> We (the -stable team) are announcing the release of the 2.6.27.16
> kernel.
> 
> It contains a wide range of bugfixes, and all users of the 2.6.27 kernel
> series are strongly encouraged to upgrade.

I get the following oops when starting hald on my Sony VAIO SZ360.

Starting Hardware abstraction layer: haldBUG: unable to handle kernel NULL pointer dereference at 00000000
IP: [<c0220048>] show_docked+0xe/0x37
*pde = 00000000
Oops: 0000 [#2] SMP
Modules linked in: autofs4 acpi_cpufreq cpufreq_conservative cpufreq_userspace cpufreq_powersave cpufreq_ondemand cpufreq_stats freq_table btusb bluetooth usbhid pcmcia arc4 ecb crypto_blkcipher cryptomgr crypto_algapi snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device joydev i2c_i801 iwl3945 pcspkr rtc_cmos tifm_7xx1 mac80211 thermal yenta_socket snd sky2 ide_cd_mod rsrc_nonstatic i2c_core rtc_core ehci_hcd pcmcia_core tifm_core bitrev soundcore uhci_hcd
sony_laptop cdrom psmouse ohci1394 rng_core rtc_lib snd_page_alloc crc32 ieee1394 usbcore evdev cfg80211 backlight battery ac processor button intel_agp agpgart unix

Pid: 2404, comm: hald Tainted: G      D   (2.6.27.16 #1)
EIP: 0060:[<c0220048>] EFLAGS: 00010282 CPU: 0
EIP is at show_docked+0xe/0x37
EAX: 00000000 EBX: f6d93000 ECX: f6d93000 EDX: f6d99f38
ESI: c03af2fc EDI: c022003a EBP: f6cdb254 ESP: f6d99f38
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process hald (pid: 2404, ti=f6d98000 task=f72c78d0 task.ti=f6d98000)
Stack: fffffff4 fffffffb c0246cc1 c03b5600 f6cdb240 f781e7c8 c01b6507 40038000
       00000003 00001000 40038000 c03b5600 f7854480 f7016940 40038000 c01b6480
       00001000 c017836d f6d99fa0 f7bf2774 f7016940 fffffff7 00000000 f6d98000
Call Trace:
 [<c0246cc1>] dev_attr_show+0x21/0x50
 [<c01b6507>] sysfs_read_file+0x87/0x120
 [<c01b6480>] sysfs_read_file+0x0/0x120
 [<c017836d>] vfs_read+0x9d/0x140
 [<c01784e1>] sys_read+0x41/0x80
 [<c01032ca>] syscall_call+0x7/0xb
 =======================
Code: fd ff 58 5a ba 02 00 00 00 8d 83 80 00 00 00 8d 4c 24 10 e8 bb f7 fc ff 83 c4 18 5b c3 53 89 cb 83 ec 04 8b 80 d8 00 00 00 89 e2 <8b> 00 8b 00 e8 77 d2 ff ff 85 c0 75 07 68 60 b1 37 c0 eb 05 68
EIP: [<c0220048>] show_docked+0xe/0x37 SS:ESP 0068:f6d99f38
---[ end trace abcf04f7c3ef131b ]---

The following change is the part which causes it.

> diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> index e28469e..eab790f 100644
> --- a/drivers/acpi/dock.c
> +++ b/drivers/acpi/dock.c
> @@ -691,8 +691,14 @@ fdd_out:
>  static ssize_t show_docked(struct device *dev,
>  			   struct device_attribute *attr, char *buf)
>  {
> -	return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
> +	struct acpi_device *tmp;
> +
> +	struct dock_station *dock_station = *((struct dock_station **)
> +		dev->platform_data);
>  
> +	if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
> +		return snprintf(buf, PAGE_SIZE, "1\n");
> +	return snprintf(buf, PAGE_SIZE, "0\n");
>  }
>  static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);

It seems that dev->platform_data is NULL on my system.

David
-- 
David Engel
david@istwok.net