Re: [PATCH 0/4] fix lpm and hash creation

[Olivier Matz <olivier.matz@6wind.com>]

On 03/30/2016 05:30 PM, Olivier Matz wrote:
> Seen while trying to fix the func_reentrancy autotest. The
> series addresses several issues:
> 
> 1/ Hash and lpm return a pointer to an existing object if the user requests the
>    creation with an already existing name. This look dangerous: when an object
>    is returned, the user does not know if it should be freed or not.
> 
> 2/ There is a race condition in cuckoo_hash as the lock is not held in
>    rte_hash_create(). We could find some cases where NULL is returned when the
>    object already exists (ex: when rte_ring_create() fails).
> 
> 3/ There is a race condition func_reentrancy that can fail even if the tested
>    API behaves correctly.
> 
> 
> Changes since RFC:
> 
> - split the patch in 4 patches
> - on error, set rte_errno to EEXIST when relevant
> - fix locking in cuckoo_hash creation
> 
> Olivier Matz (4):
>   lpm: allocation of an existing object should fail
>   hash: allocation of an existing object should fail
>   hash: keep the list locked at creation
>   autotest: fix func reentrancy
> 
>  app/test/test_func_reentrancy.c   | 31 +++++++++++++++++++++----------
>  app/test/test_lpm6.c              |  2 +-
>  lib/librte_hash/rte_cuckoo_hash.c | 18 +++++++++++++-----
>  lib/librte_hash/rte_fbk_hash.c    |  5 ++++-
>  lib/librte_lpm/rte_lpm.c          | 10 ++++++++--
>  lib/librte_lpm/rte_lpm6.c         |  5 ++++-
>  6 files changed, 51 insertions(+), 20 deletions(-)
> 

Self-nack, there is a typo in rte_cuckoo_hash.c breaking the
compilation.