diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index bf2122af94e7..c3c5c1d6103d 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -618,7 +618,8 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, struct vm_area_struct *expand) { struct mm_struct *mm = vma->vm_mm; - struct vm_area_struct *next_next, *next = find_vma(mm, vma->vm_end); + struct vm_area_struct *next_next = NULL; /* uninit var warning */ + struct vm_area_struct *next = find_vma(mm, vma->vm_end); struct vm_area_struct *orig_vma = vma; struct address_space *mapping = NULL; struct rb_root_cached *root = NULL; @@ -2625,14 +2626,14 @@ cannot_expand: if (error) goto unmap_and_free_vma; - /* Can addr have changed?? - * - * Answer: Yes, several device drivers can do it in their - * f_op->mmap method. -DaveM + /* + * Expansion is handled above, merging is handled below. + * Drivers should not alter the address of the VMA. */ - WARN_ON_ONCE(addr != vma->vm_start); - - addr = vma->vm_start; + if (WARN_ON((addr != vma->vm_start))) { + error = -EINVAL; + goto close_and_free_vma; + } mas_reset(&mas); /* @@ -2654,7 +2655,6 @@ cannot_expand: vm_area_free(vma); vma = merge; /* Update vm_flags to pick up the change. */ - addr = vma->vm_start; vm_flags = vma->vm_flags; goto unmap_writable; } @@ -2674,6 +2674,8 @@ cannot_expand: error = -EINVAL; if (file) goto close_and_free_vma; + else if (vma->vm_file) + goto unmap_and_free_vma; else goto free_vma; } @@ -2681,6 +2683,8 @@ cannot_expand: if (mas_preallocate(&mas, vma, GFP_KERNEL)) { error = -ENOMEM; if (file) + goto close_and_free_vma; + else if (vma->vm_file) goto unmap_and_free_vma; else goto free_vma; @@ -2751,7 +2755,7 @@ unmap_and_free_vma: /* Undo any partial mapping done by a device driver. */ unmap_region(mm, mas.tree, vma, prev, next, vma->vm_start, vma->vm_end); - if (vm_flags & VM_SHARED) + if (file && (vm_flags & VM_SHARED)) mapping_unmap_writable(file->f_mapping); free_vma: vm_area_free(vma); @@ -2852,6 +2856,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, if (next->vm_flags != vma->vm_flags) goto out; + if (start + size <= next->vm_end) + break; + prev = next; } |