On 08/22/2018 02:10 PM, Kirill A. Shutemov wrote:
We need mmap_sem for write in mpx_notify_unmap().For x86, mpx_notify_unmap() looks finally zap the VM_MPX vmas in bound tableI don't see anything obviously dependent on down_write() in
range with zap_page_range() and doesn't update vm flags, so it sounds ok to
me since vmas have been detached, nobody can find those vmas. But, I'm not
familiar with the details of mpx, maybe Kirill could help to confirm this?
mpx_notify_unmap(), but Dave should know better.
Its job is to clean up bounds tables, but bounds tables are dynamically
allocated and destroyed by the kernel. When we destroy a table, we also
destroy the VMA for the bounds table *itself*, separate from the VMA
But, this code is very likely to go away soon. If it's causing a
problem for you, let me know and I'll see if I can get to removing it