static void protect_vm_page(unsigned long addr, int w, int must_succeed)
{
int err;
err = protect_memory(addr, PAGE_SIZE, 1, w, 1, must_succeed);
if(err == 0) return;
else if((err == -EFAULT) || (err == -ENOMEM)){
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
protect_vm_page(addr, w, 1);
}
else panic("protect_vm_page : protect failed, errno = %d\n", err);
}
void mprotect_kernel_vm(int w)
{
struct mm_struct *mm;
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
unsigned long addr;
mm = &init_mm;
for(addr = start_vm; addr < end_vm;){
pgd = pgd_offset(mm, addr);
pmd = pmd_offset(pgd, addr);
if(pmd_present(*pmd)){
pte = pte_offset_kernel(pmd, addr);
if(pte_present(*pte)) protect_vm_page(addr, w, 0);
addr += PAGE_SIZE;
}
else addr += PMD_SIZE;
}
}
