Marco Stornelli <[email protected]> writes: > + > + do { > + pgd = pgd_offset(&init_mm, address); > + if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) > + goto out; > + > + pud = pud_offset(pgd, address); > + if (pud_none(*pud) || unlikely(pud_bad(*pud))) > + goto out; > + > + pmd = pmd_offset(pud, address); > + if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) > + goto out; > + > + ptep = pte_offset_kernel(pmd, addr); > + pte = *ptep; > + if (pte_present(pte)) {
This won't work at all on x86 because you don't handle large pages. And it doesn't work on x86-64 because the first 2GB are double mapped (direct and kernel text mapping) Thirdly I expect it won't either on architectures that map the direct mapping with special registers (like IA64 or MIPS) I'm not sure this is very useful anyways. It doesn't protect against stray DMA and it doesn't protect against writes through broken user PTEs. -Andi -- [email protected] -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
