diff options
| -rw-r--r-- | arch/arm/kernel/signal.c | 96 | ||||
| -rw-r--r-- | arch/arm/kernel/traps.c | 14 | ||||
| -rw-r--r-- | arch/arm/mm/fault-armv.c | 7 |
3 files changed, 33 insertions, 84 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index a94d75fef59..a917e3dd366 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -139,93 +139,33 @@ struct iwmmxt_sigframe { unsigned long storage[0x98/4]; }; -static int page_present(struct mm_struct *mm, void __user *uptr, int wr) -{ - unsigned long addr = (unsigned long)uptr; - pgd_t *pgd = pgd_offset(mm, addr); - if (pgd_present(*pgd)) { - pmd_t *pmd = pmd_offset(pgd, addr); - if (pmd_present(*pmd)) { - pte_t *pte = pte_offset_map(pmd, addr); - return (pte_present(*pte) && (!wr || pte_write(*pte))); - } - } - return 0; -} - -static int copy_locked(void __user *uptr, void *kptr, size_t size, int write, - void (*copyfn)(void *, void __user *)) -{ - unsigned char v, __user *userptr = uptr; - int err = 0; - - do { - struct mm_struct *mm; - - if (write) { - __put_user_error(0, userptr, err); - __put_user_error(0, userptr + size - 1, err); - } else { - __get_user_error(v, userptr, err); - __get_user_error(v, userptr + size - 1, err); - } - - if (err) - break; - - mm = current->mm; - spin_lock(&mm->page_table_lock); - if (page_present(mm, userptr, write) && - page_present(mm, userptr + size - 1, write)) { - copyfn(kptr, uptr); - } else - err = 1; - spin_unlock(&mm->page_table_lock); - } while (err); - - return err; -} - static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) { - int err = 0; + char kbuf[sizeof(*frame) + 8]; + struct iwmmxt_sigframe *kframe; /* the iWMMXt context must be 64 bit aligned */ - WARN_ON((unsigned long)frame & 7); - - __put_user_error(IWMMXT_MAGIC0, &frame->magic0, err); - __put_user_error(IWMMXT_MAGIC1, &frame->magic1, err); - - /* - * iwmmxt_task_copy() doesn't check user permissions. - * Let's do a dummy write on the upper boundary to ensure - * access to user mem is OK all way up. - */ - err |= copy_locked(&frame->storage, current_thread_info(), - sizeof(frame->storage), 1, iwmmxt_task_copy); - return err; + kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); + kframe->magic0 = IWMMXT_MAGIC0; + kframe->magic1 = IWMMXT_MAGIC1; + iwmmxt_task_copy(current_thread_info(), &kframe->storage); + return __copy_to_user(frame, kframe, sizeof(*frame)); } static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) { - unsigned long magic0, magic1; - int err = 0; + char kbuf[sizeof(*frame) + 8]; + struct iwmmxt_sigframe *kframe; - /* the iWMMXt context is 64 bit aligned */ - WARN_ON((unsigned long)frame & 7); - - /* - * Validate iWMMXt context signature. - * Also, iwmmxt_task_restore() doesn't check user permissions. - * Let's do a dummy write on the upper boundary to ensure - * access to user mem is OK all way up. - */ - __get_user_error(magic0, &frame->magic0, err); - __get_user_error(magic1, &frame->magic1, err); - if (!err && magic0 == IWMMXT_MAGIC0 && magic1 == IWMMXT_MAGIC1) - err = copy_locked(&frame->storage, current_thread_info(), - sizeof(frame->storage), 0, iwmmxt_task_restore); - return err; + /* the iWMMXt context must be 64 bit aligned */ + kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); + if (__copy_from_user(kframe, frame, sizeof(*frame))) + return -1; + if (kframe->magic0 != IWMMXT_MAGIC0 || + kframe->magic1 != IWMMXT_MAGIC1) + return -1; + iwmmxt_task_restore(current_thread_info(), &kframe->storage); + return 0; } #endif diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index baa09601a64..66e5a0516f2 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; diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index be4ab3d73c9..7fc1b35a674 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -26,6 +26,11 @@ static unsigned long shared_pte_mask = L_PTE_CACHEABLE; /* * We take the easy way out of this problem - we make the * PTE uncacheable. However, we leave the write buffer on. + * + * Note that the pte lock held when calling update_mmu_cache must also + * guard the pte (somewhere else in the same mm) that we modify here. + * Therefore those configurations which might call adjust_pte (those + * without CONFIG_CPU_CACHE_VIPT) cannot support split page_table_lock. */ static int adjust_pte(struct vm_area_struct *vma, unsigned long address) { @@ -127,7 +132,7 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page); * 2. If we have multiple shared mappings of the same space in * an object, we need to deal with the cache aliasing issues. * - * Note that the page_table_lock will be held. + * Note that the pte lock will be held. */ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte) { |