Re: [Linaro-mm-sig] [PATCH 2/6] mm: introduce vma_set_file function v3

On Fri, Oct 09, 2020 at 05:03:38PM +0200, Christian König wrote:

+/*

• • Change backing file, only valid to use during initial VMA setup.
• */

+void vma_set_file(struct vm_area_struct *vma, struct file *file) +{

• if (file)

•        get_file(file);
  

• swap(vma->vm_file, file);
• if (file)

• fput(file);
  

+}

fput crashes when file is NULL so the error handling after unmap_and_free_vma: can't handle this case, similarly vm_file can't be NULL either.

So just simply:

swap(vma->vm_file, file); get_file(vma->vm_file); fput(file);

Will do?

Just let it crash if any of them are wrongly NULL.

Jason