Re: Virt To Phys

[sridhar vaidyanathan <sridharv@ufl.edu>]

I think the requirement was to convert userland virtual addresses to physical 
addresses. The _pa and _va macros work for kernel addresses which have a direct 
mapping with the physical addresses. The only way to do the above is to walk 
the page tables. Depending on the arch you can write your own function. Take a 
look at dump_pagetable() in x86_64/mm/fault.c. Not sure if the kernel offers 
any function to do this.
-sridhar

> Aamer Jaleel (ajaleel@wam.umd.edu) wrote:
> > 
> > I'm using a kernel version 2.4.19...
> > 
> > Functions like copy to user, copy from user, clear user, etc, all use a
> > user space virtual address...  can somebody let me know how to convert a
> > user space virtual address to a physical address?  I wish to convert a
> > user space virtual address to a physical address... any help would be
> > greatly apprecaited...
> 
> I think _pa and _va is what you search.
> But perhaps it will be obselete. I don't know this. But somebosy else
> can surely answer to this question.
> 
> -- 
> Cordialement/Regards
> Christophe Lucas -- Iomeda SA (clucas@iomeda.fr)
> Developpeur/Administrateur GNU/Linux
> --
> Kernelnewbies: Help each other learn about the Linux kernel.
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> 
> 
> 


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