[alsa-devel] [BUG] NULL pointer dereference in patch_sigmatel.c

[James Courtier-Dutton]

2009/8/7 Ozan Çağlayan <ozan at pardus.org.tr>:
>
> Added the following lines:
>
> printk(KERN_INFO "0x%p\n", jack);
> printk(KERN_INFO "0x%p\n", jack->jack);
> printk(KERN_INFO "0x%p\n", jack->jack->private_data);
>
> dmesg:
>
> NVRM: loading NVIDIA UNIX x86 Kernel Module  180.51  Thu Apr 16 19:02:15
> PDT 2009
> ACPI: PCI Interrupt 0000:00:1b.0[A] -> GSI 22 (level, low) -> IRQ 22
> PCI: Setting latency timer of device 0000:00:1b.0 to 64
> 0xf777a614
> 0x00000000
> BUG: unable to handle kernel NULL pointer dereference at 00000074
> IP: [<f93f2d97>] :snd_hda_codec_conexant:conexant_add_jack+0x57/0x81
> *pde = 00000000·
> Oops: 0000 [#1] SMP
>

Need more of the dmesg output.
I.e. to see which print statements succeeded.
Alternatively, attach the snd_hda.ko so one can see where in that file
offset 0x57 is.
But a more useful print would be:
if (!jack) printk(KERN_INFO "jack null\n");
else if (!(jack->jack)) printk(KERN_INFO "jack->jack null\n");
else if (!(jack->jack->private_data)) printk(KERN_INFO
"jack->jack->private_data null\n");