Memory Read Error

Memory Read Error

[shashi59]

I am newbie for Linux Kernel.How can I read the memory area like the range
between ffff0000 to ffffffff.Directly i read that area it shows some error
like this "unable to handle kernel paging request at virtual address
ffff0000". So,I don't know, how to solve this error .Please anyone help
me....

Thanks in Advance
-Sasi-

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Re: Memory Read Error

[Randy Dunlap]

On Tue, 18 Dec 2007 02:13:30 -0800 (PST) shashi59 wrote:

> 
> I am newbie for Linux Kernel.How can I read the memory area like the range
> between ffff0000 to ffffffff.Directly i read that area it shows some error
> like this "unable to handle kernel paging request at virtual address
> ffff0000". So,I don't know, how to solve this error .Please anyone help
> me....

"Unable to handle kernel paging request at virtual address ffff...."
is almost always indicative of a kernel bug and not a memory error.

Please gather bug reporting data and report it as described in the
file: REPORTING-BUGS in the kernel source tree's top-level directory.

However:  if the kernel is very old, the answer may be just to use a
newer kernel version.  Or if the kernel is a vendor-supported kernel
version, then that vendor is probably where the bug report should go.

---
~Randy

Re: Memory Read Error

[Robert Hancock]

shashi59 wrote:
> I am newbie for Linux Kernel.How can I read the memory area like the range
> between ffff0000 to ffffffff.Directly i read that area it shows some error
> like this "unable to handle kernel paging request at virtual address
> ffff0000". So,I don't know, how to solve this error .Please anyone help
> me....

First off, why are you trying to do this and how. Without such details 
it's impossible to answer this question.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

Re: Memory Read Error

[linux-os (Dick Johnson)]

On Tue, 18 Dec 2007, Robert Hancock wrote:

> shashi59 wrote:
>> I am newbie for Linux Kernel.How can I read the memory area like the range
>> between ffff0000 to ffffffff.Directly i read that area it shows some error
>> like this "unable to handle kernel paging request at virtual address
>> ffff0000". So,I don't know, how to solve this error .Please anyone help
>> me....
>
> First off, why are you trying to do this and how. Without such details
> it's impossible to answer this question.
>
> -- 
> Robert Hancock      Saskatoon, SK, Canada
> To email, remove "nospam" from hancockr@nospamshaw.ca
> Home Page: http://www.roberthancock.com/
>

A possible hint to the newbie, with possibly English as
his last language, check out ioremap() and ioremap_nocache().
Within the kernel, these calls should allow any address
to be read, even if nothing exists at that address.


Cheers,
Dick Johnson
Penguin : Linux version 2.6.22.1 on an i686 machine (5588.29 BogoMips).
My book : http://www.AbominableFirebug.com/
_


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