LinuxQuestions.org - How to raise a page fault?

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How to raise a page fault?

Hello everyone!! I have a question.

I want to generate a page fault intentionally even if the page table entry already exists.

So I cleared a _PAGE_PRESENT bit to generate a page fault.

Here's the kernel code I wrote:

Code:

pte = get_locked_pte(mm, addr, &ptl);

entry = *pte;

entry = pte_clear_flags(entry, _PAGE_PRESENT);

set_pte_at(mm, addr, pte, entry);

pte_unmap_unlock(pte, ptl);

flush_tlb_range(vma, vma->vm_start, vma->vm_end);

However, this code does not work. The page fault I intended does not occur. I want to know exactly how I can trigger a page fault.

Thank you.

You can't "fake the system to produce a page fault" in this way. You would certainly destroy the integrity of the kernel with such an attempt.

First of all, why do you feel the need to generate a page-fault for data which exists?