Description: backport of dpdk 16.07 fix 7cc3f2c2

Author: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Date:   Tue Apr 12 15:49:27 2016 +0200

    lpm: fix freeing in compatibility mode

    Back then when we fixed the missing free lpm I was to quickly to say yes
    if it applies not only to the lpm6 but also to all of the lpm code.

    It turned out to not apply to all of them. In rte_lpm_create_v20 there
    is an unexpected fused allocation:
    mem_size = sizeof(*lpm) + (sizeof(lpm->rules_tbl[0]) * max_rules);
    [...]
    lpm = (struct rte_lpm_v20 *)rte_zmalloc_socket(mem_name,mem_size,
                   RTE_CACHE_LINE_SIZE, socket_id);

    That causes lpm->rules_tbl not to have an own struct malloc_elem that
    can be derived via RTE_PTR_SUB(data, MALLOC_ELEM_HEADER_LEN) in
    malloc_elem_from_data.
    Due to that the rte_lpm_free_v20 accidentially misderives the elem and
    assumes it is ELEM_FREE triggering in malloc_elem_free
    if (!malloc_elem_cookies_ok(elem) || elem->state !=
            return -1;

    While it seems counter-intuitive the way to properly remove rules_tbl in
    the old fused allocation style of rte_lpm_free_v20 is to not remove it.

    The newer rte_lpm_free_v1604 is safe because in rte_lpm_create_v1604
    rules_tbl is a separate allocation.

    Fixes: d4c18f0a1d5d ("lpm: fix missing free")

    Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
    Acked-by: Olivier Matz <olivier.matz@6wind.com>

Forwarded: yes (in DPDK 16.07)
Author: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Last-Update: 2016-05-17

Index: dpdk/lib/librte_lpm/rte_lpm.c
===================================================================
--- dpdk.orig/lib/librte_lpm/rte_lpm.c
+++ dpdk/lib/librte_lpm/rte_lpm.c
@@ -373,7 +373,6 @@ rte_lpm_free_v20(struct rte_lpm_v20 *lpm
 
 	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
 
-	rte_free(lpm->rules_tbl);
 	rte_free(lpm);
 	rte_free(te);
 }