On 11/25, Andi Kleen wrote:
>
> +     err = get_user_pages_fast((unsigned long)addr, npages, 1, pages);
> +     if (err < 0)
> +             return err;
> +     if (err != npages) {
> +             err = -EFAULT;
> +             goto out;
> +     }
> +     err = 0;
> +     mutex_lock(&text_mutex);
> +     bp_target_mm = current->mm;
> +     bp_int3_addr = (u8 *)addr + 1;
> +     __text_poke_bp(pages,
> +                    (unsigned long)addr & ~PAGE_MASK,
> +                    insn, len, handler);

We are going to change this user page, it seems that we need
set_page_dirty() ?

Andi, et al. I am going to discuss the things I do not really
understand, probably this can't make any sense, but...

I am wondering if sys_text_poke() can do something like

        down_write(mmap_sem);

        get_user_pages(write, page, vma);

        ptep = page_check_address(...);

        pte = ptep_clear_flush(ptep);

        copy-opcode-to-page;

        pte = pte_mkdirty(pte);
        set_pte_at(ptep, pte);

        pte_unmap_unlock(...);
        up_write(mmap_sem);

?

Oleg.

--
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/

Reply via email to