On Thu, Oct 04, 2018 at 12:28:54AM +0530, Souptick Joarder wrote: > These are the approaches which could have been taken to handle > this scenario - > > * Replace vm_insert_page with vmf_insert_page and then write few > extra lines of code to convert VM_FAULT_CODE to errno which > makes driver users more complex ( also the reverse mapping errno to > VM_FAULT_CODE have been cleaned up as part of vm_fault_t migration , > not preferred to introduce anything similar again) > > * Maintain both vm_insert_page and vmf_insert_page and use it in > respective places. But it won't gurantee that vm_insert_page will > never be used in #PF context. > > * Introduce a similar API like vm_insert_page, convert all non #PF > consumer to use it and finally remove vm_insert_page by converting > it to vmf_insert_page. > > And the 3rd approach was taken by introducing vm_insert_kmem_page(). > > In short, vmf_insert_page will be used in page fault handlers > context and vm_insert_kmem_page will be used to map kernel > memory to user vma outside page fault handlers context. As far as I can tell, vm_insert_kmem_page() is line-for-line identical with vm_insert_page(). Seriously, here's a diff I just did: -static int insert_page(struct vm_area_struct *vma, unsigned long addr, - struct page *page, pgprot_t prot) +static int insert_kmem_page(struct vm_area_struct *vma, unsigned long addr, + struct page *page, pgprot_t prot) - /* Ok, finally just insert the thing.. */ -int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, +int vm_insert_kmem_page(struct vm_area_struct *vma, unsigned long addr, - return insert_page(vma, addr, page, vma->vm_page_prot); + return insert_kmem_page(vma, addr, page, vma->vm_page_prot); -EXPORT_SYMBOL(vm_insert_page); +EXPORT_SYMBOL(vm_insert_kmem_page); What on earth are you trying to do?
