On 2023/7/14 9:52, Kefeng Wang wrote:
On 2023/7/14 4:12, Suren Baghdasaryan wrote:
On Thu, Jul 13, 2023 at 9:15 AM Matthew Wilcox <willy@xxxxxxxxxxxxx>
wrote:
+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.
I agree it is not good enough, but the arch's vma check acess has
different implementation, some use vm flags, some need fault code and
regs, and some use both :(
+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.
Ok, I could convert to use this way.
+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.
Actually I passed the vm_fault_t *ret(in the arch fault handler), we
could directly use *ret instead of a new local variable, and no copy.
Did you mean to say "we need to declare vmf (struct vm_fault) earlier
(in the arch fault handler) and pass it in." ?
After recheck the code, I think Matthew' idea is 'declare vmf (struct
vm_fault) earlier' like Suren said, not vm_fault_t, right? will try
this, thanks.
I don't think that creating struct vm_locked_fault is the
right idea either.
As mentioned above for vma check access, we need many arguments for a
function, a new struct looks possible better, is there better solution
or any suggestion?
Thanks.
