static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
unsigned long kernel)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(mm, proc);
pud = pud_alloc(mm, pgd, proc);
if (!pud)
goto out;
pmd = pmd_alloc(mm, pud, proc);
if (!pmd)
goto out_pmd;
pte = pte_alloc_map(mm, NULL, pmd, proc);
if (!pte)
goto out_pte;
*pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
*pte = pte_mkread(*pte);
return 0;
out_pte:
pmd_free(mm, pmd);
out_pmd:
pud_free(mm, pud);
out:
return -ENOMEM;
}
static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
unsigned long kernel)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(mm, proc);
pud = pud_alloc(mm, pgd, proc);
if (!pud)
goto out;
pmd = pmd_alloc(mm, pud, proc);
if (!pmd)
goto out_pmd;
pte = pte_alloc_map(mm, pmd, proc);
if (!pte)
goto out_pte;
/* There's an interaction between the skas0 stub pages, stack
* randomization, and the BUG at the end of exit_mmap. exit_mmap
* checks that the number of page tables freed is the same as had
* been allocated. If the stack is on the last page table page,
* then the stack pte page will be freed, and if not, it won't. To
* avoid having to know where the stack is, or if the process mapped
* something at the top of its address space for some other reason,
* we set TASK_SIZE to end at the start of the last page table.
* This keeps exit_mmap off the last page, but introduces a leak
* of that page. So, we hang onto it here and free it in
* destroy_context_skas.
*/
mm->context.skas.last_page_table = pmd_page_vaddr(*pmd);
#ifdef CONFIG_3_LEVEL_PGTABLES
mm->context.skas.last_pmd = (unsigned long) __va(pud_val(*pud));
#endif
*pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
*pte = pte_mkread(*pte);
return(0);
out_pmd:
pud_free(pud);
out_pte:
pmd_free(pmd);
out:
return(-ENOMEM);
}
