> +int try_vma_locked_page_fault(struct vm_locked_fault *vmlf, vm_fault_t *ret)
> +{
> + struct vm_area_struct *vma;
> + vm_fault_t fault;
On Thu, Jul 13, 2023 at 05:53:29PM +0800, Kefeng Wang wrote:
> +#define VM_LOCKED_FAULT_INIT(_name, _mm, _address, _fault_flags, _vm_flags,
> _regs, _fault_code) \
> + _name.mm = _mm; \
> + _name.address = _address; \
> + _name.fault_flags = _fault_flags; \
> + _name.vm_flags = _vm_flags; \
> + _name.regs = _regs; \
> + _name.fault_code = _fault_code
More consolidated code is a good idea; no question. But I don't think
this is the right way to do it.
> +int __weak arch_vma_check_access(struct vm_area_struct *vma,
> + struct vm_locked_fault *vmlf);
This should be:
#ifndef vma_check_access
bool vma_check_access(struct vm_area_struct *vma, )
{
return (vma->vm_flags & vm_flags) == 0;
}
#endif
and then arches which want to do something different can just define
vma_check_access.
> +int try_vma_locked_page_fault(struct vm_locked_fault *vmlf, vm_fault_t *ret)
> +{
> + struct vm_area_struct *vma;
> + vm_fault_t fault;
Declaring the vmf in this function and then copying it back is just wrong.
We need to declare vm_fault_t earlier (in the arch fault handler) and
pass it in. I don't think that creating struct vm_locked_fault is the
right idea either.
> + if (!(vmlf->fault_flags & FAULT_FLAG_USER))
> + return -EINVAL;
> +
> + vma = lock_vma_under_rcu(vmlf->mm, vmlf->address);
> + if (!vma)
> + return -EINVAL;
> +
> + if (arch_vma_check_access(vma, vmlf)) {
> + vma_end_read(vma);
> + return -EINVAL;
> + }
> +
> + fault = handle_mm_fault(vma, vmlf->address,
> + vmlf->fault_flags | FAULT_FLAG_VMA_LOCK,
> + vmlf->regs);
> + *ret = fault;
> +
> + if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
> + vma_end_read(vma);
> +
> + if ((fault & VM_FAULT_RETRY))
> + count_vm_vma_lock_event(VMA_LOCK_RETRY);
> + else
> + count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
> +
> + return 0;
> +}
> +
> #endif /* CONFIG_PER_VMA_LOCK */
>
> #ifndef __PAGETABLE_P4D_FOLDED
> --
> 2.27.0
>
>
