[dpdk-dev] [PATCH v2] ethdev: verify reserved HW ring

[Ferruh Yigit <ferruh.yigit@intel.com>]

Function 'rte_eth_dma_zone_reserve()' returns an existing memzone based
on name match, but other requested attributes are discarded.
This may cause driver using a memzone with wrong size or alignment.

Verify size, alignment and socket_id for matched memzone, and do not use
memzone if any one of the attributes are not justified.

It is possible to free the existing memzone and allocate again with the
requested attributes but it is better caller do the explicit free.

Reported-by: Renata Saiakhova <renata.saiakhova@ekinops.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
Cc: Anatoly Burakov <anatoly.burakov@intel.com>

v2:
* Updated commit log related decision on not doing implicit free
* Updated alignment check to make it more explicit
---
 lib/librte_ethdev/rte_ethdev.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 8e10a6fc3..d24db66fb 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -4202,8 +4202,18 @@ rte_eth_dma_zone_reserve(const struct rte_eth_dev *dev, const char *ring_name,
 	}
 
 	mz = rte_memzone_lookup(z_name);
-	if (mz)
+	if (mz) {
+		if ((socket_id != SOCKET_ID_ANY && socket_id != mz->socket_id) ||
+				size > mz->len ||
+				((uintptr_t)mz->addr & (align - 1)) != 0) {
+			RTE_ETHDEV_LOG(ERR,
+				"memzone %s does not justify the requested attributes\n",
+				mz->name);
+			return NULL;
+		}
+
 		return mz;
+	}
 
 	return rte_memzone_reserve_aligned(z_name, size, socket_id,
 			RTE_MEMZONE_IOVA_CONTIG, align);
-- 
2.25.4