RE: How to access kernel memory?

RE: How to access kernel memory?

[Siders, Keith]

I have just the opposite requirement. I need to allow any running process
and its threads to be "hot-patched" with executable code. I know you're
thinking "why?". I can't tell you that. I can only say  it's a firm
requirement, and I could use some helpful ideas.

Keith 

-> -----Original Message-----
-> From: Zhang Fuxin [mailto:fxzhang@ict.ac.cn]
-> Sent: Tuesday, September 18, 2001 9:53 AM
-> To: han han
-> Cc: linux-mips@oss.sgi.com
-> Subject: Re: How to access kernel memory?
-> 
-> 
-> hi,han han，
->    There are several ways.For example:
->    1.You can create a character device , implement its mmap function
-> to map the memory block you allcated.This can be done in a little
-> kernel module.There are some sample code before.
->    2.via /dev/mem,/dev/kmem etc
->    
-> 
-> 
-> 
-> 在 2001-09-18 07:35:00 you wrote：
-> >Hi, All,
-> >
-> >I allocated a block of memory in the kernel space. But
-> >I don't know how to directly access kernel space from
-> >user space. Anyone can help me?
-> >
-> >Thanks in advance.
-> >
-> >piggie
-> >
-> >
-> >__________________________________________________
-> >Terrorist Attacks on U.S. - How can you help?
-> >Donate cash, emergency relief information
-> >http://dailynews.yahoo.com/fc/US/Emergency_Information/
-> 
-> Regards
->             Zhang Fuxin
->             fxzhang@ict.ac.cn
-> 

Re: How to access kernel memory?

[Daniel Jacobowitz]

On Tue, Sep 18, 2001 at 09:59:07AM -0500, Siders, Keith wrote:
> I have just the opposite requirement. I need to allow any running process
> and its threads to be "hot-patched" with executable code. I know you're
> thinking "why?". I can't tell you that. I can only say  it's a firm
> requirement, and I could use some helpful ideas.

You can probably do all you need in this case with ptrace() - the
existing ptrace will not be quite adequate for large data sets,
especially if you need some atomicity, but it should have all the
sample kernel code you need.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: How to access kernel memory?

[han han]

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>    There are several ways.For example:
>    1.You can create a character device , implement
> its mmap function
> to map the memory block you allcated.This can be
> done in a little
> kernel module.There are some sample code before.
>    2.via /dev/mem,/dev/kmem etc

If allocating a block memory in the user space. I can
use functions like "map_user_kiobuf()" to lock it in
the physical memory and access it in the kernel space.
Does there exist corresponding methods to give my
application ability to directly access it without
using any kinds of mem/character devices?

> 
> 
> 
> 
> ÔÚ 2001-09-18 07:35:00 you wrote£º
> >Hi, All,
> >
> >I allocated a block of memory in the kernel space.
> But
> >I don't know how to directly access kernel space
> from
> >user space. Anyone can help me?
> >
> >Thanks in advance.
> >
> >piggie
> >
> >
> >__________________________________________________
> >Terrorist Attacks on U.S. - How can you help?
> >Donate cash, emergency relief information
>
>http://dailynews.yahoo.com/fc/US/Emergency_Information/
> 
> Regards
>             Zhang Fuxin
>             fxzhang@ict.ac.cn
> 


__________________________________________________
Terrorist Attacks on U.S. - How can you help?
Donate cash, emergency relief information
http://dailynews.yahoo.com/fc/US/Emergency_Information/

Re: How to access kernel memory?

[Zhang Fuxin]

hi,han han，
   There are several ways.For example:
   1.You can create a character device , implement its mmap function
to map the memory block you allcated.This can be done in a little
kernel module.There are some sample code before.
   2.via /dev/mem,/dev/kmem etc
   



在 2001-09-18 07:35:00 you wrote：
>Hi, All,
>
>I allocated a block of memory in the kernel space. But
>I don't know how to directly access kernel space from
>user space. Anyone can help me?
>
>Thanks in advance.
>
>piggie
>
>
>__________________________________________________
>Terrorist Attacks on U.S. - How can you help?
>Donate cash, emergency relief information
>http://dailynews.yahoo.com/fc/US/Emergency_Information/

Regards
            Zhang Fuxin
            fxzhang@ict.ac.cn

How to access kernel memory?

[han han]

Hi, All,

I allocated a block of memory in the kernel space. But
I don't know how to directly access kernel space from
user space. Anyone can help me?

Thanks in advance.

piggie


__________________________________________________
Terrorist Attacks on U.S. - How can you help?
Donate cash, emergency relief information
http://dailynews.yahoo.com/fc/US/Emergency_Information/