Oct. 17, 2017
3:54 a.m.
Hi Perr, On Mon, Oct 16, 2017 at 11:54:47PM +0800, Perr Zhang wrote:
Why should we use the function max() on 'start' and 'vma->vm_start'? Could the 'start' be less than 'vma->vm_start'? If it is so, isn't it wrong to just return vma->vm_start but report an error?
The vma_address() function was recently changed in commit a8fa41ad2f6f7. In the previous version, having the return value of __vma_address() lower than vma->vm_start was actually triggering a VM_BUG_ON_VMA. Taking a look at this commit and understanding why such changes had to be done might help you find an answer to your question :) -- Thibaut SAUTEREAU