On Wed, Dec 18, 2013 at 03:53:49PM +0900, Joonsoo Kim wrote: > There is a race condition if we map a same file on different processes. > Region tracking is protected by mmap_sem and hugetlb_instantiation_mutex. > When we do mmap, we don't grab a hugetlb_instantiation_mutex, but, > grab a mmap_sem. This doesn't prevent other process to modify region > structure, so it can be modified by two processes concurrently. > > To solve this, I introduce a lock to resv_map and make region manipulation > function grab a lock before they do actual work. This makes region > tracking safe. It's not clear to me if you're saying there is a list corruption race bug in the existing code, or only that there will be if the instantiation mutex goes away. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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