diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 48 |
1 files changed, 0 insertions, 48 deletions
diff --git a/mm/memory.c b/mm/memory.c index 6be9914ddc0d..17c9186c819a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1659,12 +1659,6 @@ no_page_table: return page; } -static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr) -{ - return stack_guard_page_start(vma, addr) || - stack_guard_page_end(vma, addr+PAGE_SIZE); -} - /** * replace_cma_page() - migrate page out of CMA page blocks * @page: source page to be migrated @@ -1875,10 +1869,6 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, fault_flags = FAULT_FLAG_NO_CMA; /* For mlock, just skip the stack guard page. */ - if (foll_flags & FOLL_MLOCK) { - if (stack_guard_page(vma, start)) - goto next_page; - } if (foll_flags & FOLL_WRITE) fault_flags |= FAULT_FLAG_WRITE; if (nonblocking) @@ -3171,40 +3161,6 @@ out_release: return ret; } -/* - * This is like a special single-page "expand_{down|up}wards()", - * except we must first make sure that 'address{-|+}PAGE_SIZE' - * doesn't hit another vma. - */ -static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address) -{ - address &= PAGE_MASK; - if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) { - struct vm_area_struct *prev = vma->vm_prev; - - /* - * Is there a mapping abutting this one below? - * - * That's only ok if it's the same stack mapping - * that has gotten split.. - */ - if (prev && prev->vm_end == address) - return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM; - - expand_downwards(vma, address - PAGE_SIZE); - } - if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) { - struct vm_area_struct *next = vma->vm_next; - - /* As VM_GROWSDOWN but s/below/above/ */ - if (next && next->vm_start == address + PAGE_SIZE) - return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM; - - expand_upwards(vma, address + PAGE_SIZE); - } - return 0; -} - bool is_vma_temporary_stack(struct vm_area_struct *vma); /* * We enter with non-exclusive mmap_sem (to exclude vma changes, @@ -3221,10 +3177,6 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, pte_unmap(page_table); - /* Check if we need to add a guard page to the stack */ - if (check_stack_guard_page(vma, address) < 0) - return VM_FAULT_SIGBUS; - /* Use the zero-page for reads */ if (!(flags & FAULT_FLAG_WRITE)) { entry = pte_mkspecial(pfn_pte(my_zero_pfn(address), |