/*
* First Level Translation Fault Handler
*
* We enter here because the first level page table doesn't contain
* a valid entry for the address.
*
* If the address is in kernel space (>= TASK_SIZE), then we are
* probably faulting in the vmalloc() area.
*
* If the init_task's first level page tables contains the relevant
* entry, we copy the it to this task. If not, we send the process
* a signal, fixup the exception, or oops the kernel.
*
* NOTE! We MUST NOT take any locks for this case. We may be in an
* interrupt or a critical region, and should only copy the information
* from the master page table, nothing more.
*/
int do_translation_fault(unsigned long addr, int error_code, struct pt_regs *regs)
{
struct task_struct *tsk;
struct mm_struct *mm;
int offset;
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
if (addr < TASK_SIZE)
return do_page_fault(addr, error_code, regs);
offset = __pgd_offset(addr);
pgd = cpu_get_pgd() + offset;
pgd_k = init_mm.pgd + offset;
if (pgd_none(*pgd_k))
goto bad_area;
#if 0 /* note that we are two-level */
if (!pgd_present(*pgd))
set_pgd(pgd, *pgd_k);
#endif
pmd_k = pmd_offset(pgd_k, addr);
pmd = pmd_offset(pgd, addr);
if (pmd_none(*pmd_k))
goto bad_area;
set_pmd(pmd, *pmd_k);
return 0;
bad_area:
tsk = current;
mm = tsk->active_mm;
do_bad_area(tsk, mm, addr, error_code, regs);
return 0;
}
/*
* Some section permission faults need to be handled gracefully. They can
* happen due to a __{get,put}_user during an oops.
*/
static int do_sect_fault(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
do_bad_area(addr, esr, regs);
return 0;
}
