On Wed, 22 Aug 2012, Xiao Guangrong wrote: > On 08/21/2012 11:06 PM, Andrea Arcangeli wrote: > > > > The KSM usage of it looks safe because it will only establish readonly > > ptes with it. > > Hmm, in KSM code, i found this code in replace_page: > > set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot)); > > It is possible to establish a writable pte, no?
No: we only do KSM in private vmas (!VM_SHARED), and because of the need to CopyOnWrite in those, vm_page_prot excludes write permission: write permission has to be added on COW fault. Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
