Oops: Kernel access of bad area, sig: 11 [#1]

Oops: Kernel access of bad area, sig: 11 [#1]

[Ramon Fried]

Hi.
I'm developing a driver on PowerPC kernel version 3.10.
Once In a while, I get the following OOPS and the system freezes.

Unable to handle kernel paging request for data at address 0xffffffdc 
Faulting instruction address: 0xfb7780c8 
Oops: Kernel access of bad area, sig: 11 [#1] 

When I look at the address where the paging fails, it looks like a wrong address (0xffffffdc).
The stack trace points to a list_for_each() macro.
Could it be that NULL linked list node container off was called ? Am I in the right direction ?

Thanks,
Ramon

Oops: Kernel access of bad area, sig: 11 [#1]

[Manish Katiyar]

On Sat, Aug 22, 2015 at 10:51 PM, Ramon Fried <ramon.fried@tandemg.com> wrote:
> Hi.
> I'm developing a driver on PowerPC kernel version 3.10.
> Once In a while, I get the following OOPS and the system freezes.
>
> Unable to handle kernel paging request for data at address 0xffffffdc
> Faulting instruction address: 0xfb7780c8
> Oops: Kernel access of bad area, sig: 11 [#1]
>
> When I look at the address where the paging fails, it looks like a wrong address (0xffffffdc).
> The stack trace points to a list_for_each() macro.
> Could it be that NULL linked list node container off was called ? Am I in the right direction ?

You should try to find out if the number 0xdc has any significance. Is
it an offset of the member in the structure that you are trying to
access. If yes, then you know what the structure address was (most
probably -1 or something like that), then backtrack how can you have
that value.

HTH

Oops: Kernel access of bad area, sig: 11 [#1]

[Valdis.Kletnieks at vt.edu]

On Sun, 23 Aug 2015 05:51:12 -0000, Ramon Fried said:

> Unable to handle kernel paging request for data at address 0xffffffdc

Hmm.. Somebody missed an IS_ERR() macro?  That's a -22, -EINVAL.
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