Re: [dpdk-dev] [PATCH v3 0/9] Make DPDK tailqs fully local

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> This issue was reported by OVS-DPDK project, and the fix should go to
> upstream DPDK. This is not memnic-related - this is to do with
> DPDK's rte_ivshmem library.
> 
> Every DPDK data structure has a corresponding TAILQ reserved for it in
> the runtime config file. Those TAILQs are fully local to the process,
> however most data structures contain pointers to next entry in the
> TAILQ.
> 
> Since the data structures such as rings are shared in their entirety,
> those TAILQ pointers are shared as well. Meaning that, after a
> successful rte_ring creation, the tailq_next pointer of the last
> ring in the TAILQ will be updated with a pointer to a ring which may
> not be present in the address space of another process (i.e. a ring
> that may be host-local or guest-local, and not shared over IVSHMEM).
> Any successive ring create/lookup on the other side of IVSHMEM will
> result in trying to dereference an invalid pointer.
> 
> This patchset fixes this problem by creating a default tailq entry
> that may be used by any data structure that chooses to use TAILQs.
> This default TAILQ entry will consist of a tailq_next/tailq_prev
> pointers, and an opaque pointer to arbitrary data. All TAILQ
> pointers from data structures themselves will be removed and
> replaced by those generic TAILQ entries, thus fixing the problem
> of potentially exposing local address space to shared structures.
> 
> Technically, only rte_ring structure require modification, because
> IVSHMEM is only using memzones (which aren't in TAILQs) and rings,
> but for consistency's sake other TAILQ-based data structures were
> adapted as well.
> 
> v2 changes:
> * fixed race conditions in *_free operations
> * fixed multiprocess support for malloc heaps
> * added similar changes for acl
> * rebased on top of e88b42f818bc1a6d4ce6cb70371b66e37fa34f7d
> 
> v3 changes:
> * fixed race reported by Konstantin Ananyev (introduced in v2)
> 
> Anatoly Burakov (9):
>   eal: map shared config into exact same address as primary process
>   rte_tailq: change rte_dummy to rte_tailq_entry, add data pointer
>   rte_ring: make ring tailq fully local
>   rte_hash: make rte_hash tailq fully local
>   rte_fbk_hash: make rte_fbk_hash tailq fully local
>   rte_mempool: make mempool tailq fully local
>   rte_lpm: make lpm tailq fully local
>   rte_lpm6: make lpm6 tailq fully local
>   rte_acl: make acl tailq fully local
> 
>  app/test/test_tailq.c                             | 33 +++++-----
>  lib/librte_acl/acl.h                              |  1 -
>  lib/librte_acl/rte_acl.c                          | 74 ++++++++++++++++++-----
>  lib/librte_eal/common/eal_common_tailqs.c         |  2 +-
>  lib/librte_eal/common/include/rte_eal_memconfig.h |  5 ++
>  lib/librte_eal/common/include/rte_tailq.h         |  9 +--
>  lib/librte_eal/linuxapp/eal/eal.c                 | 44 ++++++++++++--
>  lib/librte_eal/linuxapp/eal/eal_ivshmem.c         | 17 +++++-
>  lib/librte_hash/rte_fbk_hash.c                    | 73 +++++++++++++++++-----
>  lib/librte_hash/rte_fbk_hash.h                    |  3 -
>  lib/librte_hash/rte_hash.c                        | 61 ++++++++++++++++---
>  lib/librte_hash/rte_hash.h                        |  2 -
>  lib/librte_lpm/rte_lpm.c                          | 65 ++++++++++++++++----
>  lib/librte_lpm/rte_lpm.h                          |  2 -
>  lib/librte_lpm/rte_lpm6.c                         | 62 +++++++++++++++----
>  lib/librte_mempool/Makefile                       |  3 +-
>  lib/librte_mempool/rte_mempool.c                  | 37 +++++++++---
>  lib/librte_mempool/rte_mempool.h                  |  2 -
>  lib/librte_ring/Makefile                          |  4 +-
>  lib/librte_ring/rte_ring.c                        | 33 +++++++---
>  lib/librte_ring/rte_ring.h                        |  2 -
>  21 files changed, 415 insertions(+), 119 deletions(-)
> 
> --

Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>