Re: Calculating kernel logical address ..
Manfred Spraul (manfred@colorfullife.com)
Fri, 06 Sep 2002 17:44:29 +0200
> adr = user_address;
> pgd_offset(current->mm, adr);
>
> if (!pgd_none(*pgd)) {
> pmd = pmd_offset(pgd, adr);
> if (!pmd_none(*pmd)) {
> ptep = pte_offset(pmd, adr);
> pte = *ptep;
> if(pte_present(pte)) {
> kaddr = (unsigned long) page_address(pte_page(pte));
> kaddr |= (adr & (PAGE_SIZE - 1));
> }
> }
> }
>
> Will this code always give me correct kernel logical address?
>
What about
kmalloc_buffer+(user_address-vma->vm_start)
?
A driver should avoid accessing the page tables.
--
Manfred
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/