Messages in this thread | | | From | "Reshetova, Elena" <> | Subject | RE: [PATCH 06/16] drivers, net, mlx5: convert mlx5_cq.refcount from atomic_t to refcount_t | Date | Tue, 28 Mar 2017 14:00:01 +0000 |
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> From: Elena Reshetova > > Sent: 28 March 2017 09:57 > > > > refcount_t type and corresponding API should be > > used instead of atomic_t when the variable is used as > > a reference counter. This allows to avoid accidental > > refcounter overflows that might lead to use-after-free > > situations. > > I can't help feeling that you ought to find a scheme > that will detect extra decrements and extra increments > before the counter wraps 32 bits. > > If an extra reference is requested every 100us it takes 4.8 days > for the counter to increment back to zero. > Simple tests aren't doing to find that - but it can easily happen > on a system that is running for several years.
So, you are proposing to try detecting this case instead of preventing overflows? Not sure how this would look like in a generic form...
> > David
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