diff options
Diffstat (limited to 'arch/arm/kernel/traps.c')
| -rw-r--r-- | arch/arm/kernel/traps.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index baa09601a64e..66e5a0516f23 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -483,29 +483,33 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs) unsigned long addr = regs->ARM_r2; struct mm_struct *mm = current->mm; pgd_t *pgd; pmd_t *pmd; pte_t *pte; + spinlock_t *ptl; regs->ARM_cpsr &= ~PSR_C_BIT; - spin_lock(&mm->page_table_lock); + down_read(&mm->mmap_sem); pgd = pgd_offset(mm, addr); if (!pgd_present(*pgd)) goto bad_access; pmd = pmd_offset(pgd, addr); if (!pmd_present(*pmd)) goto bad_access; - pte = pte_offset_map(pmd, addr); - if (!pte_present(*pte) || !pte_write(*pte)) + pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + if (!pte_present(*pte) || !pte_write(*pte)) { + pte_unmap_unlock(pte, ptl); goto bad_access; + } val = *(unsigned long *)addr; val -= regs->ARM_r0; if (val == 0) { *(unsigned long *)addr = regs->ARM_r1; regs->ARM_cpsr |= PSR_C_BIT; } - spin_unlock(&mm->page_table_lock); + pte_unmap_unlock(pte, ptl); + up_read(&mm->mmap_sem); return val; bad_access: - spin_unlock(&mm->page_table_lock); + up_read(&mm->mmap_sem); /* simulate a write access fault */ do_DataAbort(addr, 15 + (1 << 11), regs); return -1; |