Re: "copy_to_user" function not working in stable build ""

From: zubraz singha
Date: Sun Jul 27 2014 - 04:44:42 EST

I do understand that this is a very old build and its not being
supported. As I wrote in my earlier mail, the function works fine
with higher kernel versions. I will try to find out a work around for
this. Appreciate your feedback.


On 7/27/14, Richard Weinberger <richard.weinberger@xxxxxxxxx> wrote:
> On Sun, Jul 27, 2014 at 10:22 AM, zubraz singha <zubrajsingha@xxxxxxxxx>
> wrote:
>> Hey Guys,
>> While writing a read proc entry for Linux kernel (version, I
>> found that the kernel function "copy_to_user" is not working properly.
>> The kernel function used internally by "copy_to_user" i.e.
>> "__copy_to_user" works fine and also this same function "copy_to_user"
>> works quite well on the higher kernel versions, I tried it on Linux
>> kernel version 3.14. The kernel source code for "" doesn't
>> have a definition for a function i.e "_copy_to_user", which is being
>> called internally by "copy_to_user". However the function
>> "_copy_to_user" has a definition in higher version kernels like 3.14
>> etc. I cannot update my kernel, Is there any way I can fix this issue
>> by manually patching the kernel. There are two possible ways in which
>> I think it can be solved.
>> - Write a definition for the _copy_to_user in "", which will
>> have the same "access_ok" check and corresponding "__copy_to_user"
>> function call.
>> - Modifying the function "copy_to_user" and adding the "access_ok"
>> check and the "__copy_to_user" function.
> 2.6.36.x is not a supported release. The issue is maybe fixed in other
> versions but as
> your release is not a stable kernel you are on your own. Sorry.
> --
> Thanks,
> //richard

-- Regards
Zubraj Singha
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at