77 lines
1.3 KiB
C
77 lines
1.3 KiB
C
#include <linux/mm.h>
|
|
#include <linux/pgtable.h>
|
|
#include <linux/printk.h>
|
|
#include <asm/current.h>
|
|
|
|
#include "util.h"
|
|
|
|
bool try_set_access_flag(unsigned long addr)
|
|
{
|
|
#ifdef CONFIG_ARM64
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
pgd_t *pgd;
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pte_t *ptep, pte;
|
|
spinlock_t *ptl;
|
|
bool ret = false;
|
|
|
|
if (!mm)
|
|
return false;
|
|
|
|
if (!mmap_read_trylock(mm))
|
|
return false;
|
|
|
|
vma = find_vma(mm, addr);
|
|
if (!vma || addr < vma->vm_start)
|
|
goto out_unlock;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
if (!pgd_present(*pgd))
|
|
goto out_unlock;
|
|
|
|
p4d = p4d_offset(pgd, addr);
|
|
if (!p4d_present(*p4d))
|
|
goto out_unlock;
|
|
|
|
pud = pud_offset(p4d, addr);
|
|
if (!pud_present(*pud))
|
|
goto out_unlock;
|
|
|
|
pmd = pmd_offset(pud, addr);
|
|
if (!pmd_present(*pmd))
|
|
goto out_unlock;
|
|
|
|
if (pmd_trans_huge(*pmd))
|
|
goto out_unlock;
|
|
|
|
ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
|
|
if (!ptep)
|
|
goto out_unlock;
|
|
|
|
pte = *ptep;
|
|
|
|
if (!pte_present(pte))
|
|
goto out_pte_unlock;
|
|
|
|
if (pte_young(pte)) {
|
|
ret = true;
|
|
goto out_pte_unlock;
|
|
}
|
|
|
|
ptep_set_access_flags(vma, addr, ptep, pte_mkyoung(pte), 0);
|
|
pr_info("set AF for addr %lx\n", addr);
|
|
ret = true;
|
|
|
|
out_pte_unlock:
|
|
pte_unmap_unlock(ptep, ptl);
|
|
out_unlock:
|
|
mmap_read_unlock(mm);
|
|
return ret;
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|