On Tuesday 23 August 2005 05:59, Gaurav Dhiman wrote:
> > A preliminary statement:
> > mtpmc_old_handler contains the address of the original handler
> >
> > 1. static asmlinkage void mtpmc_handler(struct pt_regs * regs,long
> > error_code)
> > 2. {
> > 3. unsigned long address;
> > 4. struct task_struct *task;
> > 5. struct mm_struct *mm;
> >
> > 6. pid_t pid = current->pid;
> > 7. int hijack = 0;
> >
> > 8. /* gets the address */
> > 9. __asm__("movl %%cr2,%0":"=r" (address));
> >
> > 10. if (the error is a writing error on one of the pages that we've
setted
> > as not writable)
> > 11. {
> > 12. printk(KERN_DEBUG "page fault handling\n");
> > 13. send_sig(SIGSTOP, current, 1);
> > 14. mtpmc_restore_page_writable(current->mm, address);
> > 15. mtpmc_restore_page_not_writable(current->mm, address);
>
> for this, its important to know what exactly you are doing in these
> two function, can you paste the code of these functions, I think these
> are function of your module.
Oh yes. I'm sorry. I've not posted the two functions.
These are listed below.
Vincenzo.
void mtpmc_restore_page_not_writable(struct mm_struct *mm, unsigned long addr)
{
pte_t *pte;
pte = mtpmc_get_pte_from_address(mm, addr);
if (pte != NULL)
if (pte_write(*pte))
set_pte(pte, pte_wrprotect(*pte));
return;
}
void mtpmc_restore_page_writable(struct mm_struct *mm, unsigned long addr)
{
pte_t *pte;
pte = mtpmc_get_pte_from_address(mm, addr);
if (pte != NULL)
if (!pte_write(*pte))
set_pte(pte, pte_mkwrite(*pte));
return;
}
mtpmc_get_pte_from_address return the pointer to pte related to the page with
given address.
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