From: Kefeng Wang <wangkefeng.wang@huawei.com> ohos inclusion category: bugfix issue: #I3ZXZF CVE: NA Reference: https://lore.kernel.org/linux-arm-kernel/20210610123556.171328-1-wangkefeng.... ------------------------------------------------- Clean up the multiple goto statements and drops local variable vm_fault_t fault, which will make the __do_page_fault() much more readability. No functional change. Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Yu Changchun <yuchangchun1@huawei.com> --- arch/arm/mm/fault.c | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index efa402025031..662ac3ca3c8a 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -205,35 +205,27 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, unsigned int flags, struct task_struct *tsk, struct pt_regs *regs) { - struct vm_area_struct *vma; - vm_fault_t fault; - - vma = find_vma(mm, addr); - fault = VM_FAULT_BADMAP; + struct vm_area_struct *vma = find_vma(mm, addr); if (unlikely(!vma)) - goto out; - if (unlikely(vma->vm_start > addr)) - goto check_stack; + return VM_FAULT_BADMAP; + + if (unlikely(vma->vm_start > addr)) { + if (!(vma->vm_flags & VM_GROWSDOWN)) + return VM_FAULT_BADMAP; + if (addr < FIRST_USER_ADDRESS) + return VM_FAULT_BADMAP; + if (expand_stack(vma, addr)) + return VM_FAULT_BADMAP; + } /* * Ok, we have a good vm_area for this * memory access, so we can handle it. */ -good_area: - if (access_error(fsr, vma)) { - fault = VM_FAULT_BADACCESS; - goto out; - } + if (access_error(fsr, vma)) + return VM_FAULT_BADACCESS; return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); - -check_stack: - /* Don't allow expansion below FIRST_USER_ADDRESS */ - if (vma->vm_flags & VM_GROWSDOWN && - addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr)) - goto good_area; -out: - return fault; } static int __kprobes -- 2.22.0