Hello Everybody,
I am trying to use the seq_file methods for printing to a proc file. I did everything as in Rubini ,the driver works fine, but when I do open the /proc/scullseq file I get a kernel dump. The driver I used was scull as in Rubini.....
I commented out all the code form .start,.next,stop and .show ....adding only afew printks to know that the kernel had indeed accessed them - but i did not get any prints either.......
I do not have a proper idea about the working of the .show,.start and .stop functionalities...could anyone enlighten me on this....from what I understood from Rubini.....the kernel calls these methods when it has the free time....or does it work in some other manner.....All other device registration too was done as per Rubini....from the back of my head...I have a feeling that it has
something to do with the ScullDriver pointer I passed to the kernel back from these methods.....
I have cut and paste the kernel dump below...please do let me know of your feedback...
Thanks In Advance,
G.
***********************************************************************************
printing eip:
c0153822
*pde = 1c530067
Oops: 0000 [#17]
PREEMPT
Modules linked in: scull radeon drm ppdev hidp rfcomm l2cap bluetooth video button battery ac ipv6 lp parport_pc parport nvram joydev snd_ali5451 snd_ac97_codec snd_ac97_bus snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm i2c_ali1535 i2c_ali15x3 i2c_core snd_timer snd soundcore snd_page_alloc tg3
CPU: 0
EIP: 0060:[<c0153822>] Tainted: P R VLI
EFLAGS: 00210282 (2.6.16 #2)
EIP is at __dentry_open+0xe6/0x201
eax: deca8fe0 ebx: c4bc3938 ecx: 0000000d edx: 00000001
esi: 00000000 edi: c74a99f0 ebp: 00000003 esp: c4a7ef24
ds: 007b es: 007b ss: 0068
Process vi (pid: 4906, threadinfo=c4a7e000 task=c39738f0)
Stack: <0>ddfc4b68 c58dd4c8 c4bc3938 c4a7ef50 4e26bff4 00000003 c01539a1 c4bc3938
00000000 00008000 c01539db c58dd4c8 ddfc4b68 ddfcc600 c4a3330c c0150f4b
00000101 00000001 00000000 00000003 0000001d 00000003 ffffff9c 0000000c
Call Trace:
[<c01539a1>] nameidata_to_filp+0x19/0x28
[<c01539db>] do_filp_open+0x2b/0x31
[<c0150f4b>] cache_alloc_debugcheck_after+0x2d/0xea
[<c05351b0>] _spin_unlock+0xf/0x23
[<c015485e>] do_sys_open+0x3e/0xaa
[<c0102b5b>] sysenter_past_esp+0x54/0x75
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