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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Avihai Horon <avihaih@nvidia.com>,
        Mark Zhang <markzhang@nvidia.com>,
        Leon Romanovsky <leonro@nvidia.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 110/239] RDMA/core: Let ib_find_gid() continue search even after empty entry
Date:   Mon, 24 Jan 2022 19:42:28 +0100
Message-Id: <20220124183946.600613206@linuxfoundation.org>
In-Reply-To: <20220124183943.102762895@linuxfoundation.org>
References: <20220124183943.102762895@linuxfoundation.org>
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From: Avihai Horon <avihaih@nvidia.com>

[ Upstream commit 483d805191a23191f8294bbf9b4e94836f5d92e4 ]

Currently, ib_find_gid() will stop searching after encountering the first
empty GID table entry. This behavior is wrong since neither IB nor RoCE
spec enforce tightly packed GID tables.

For example, when a valid GID entry exists at index N, and if a GID entry
is empty at index N-1, ib_find_gid() will fail to find the valid entry.

Fix it by making ib_find_gid() continue searching even after encountering
missing entries.

Fixes: 5eb620c81ce3 ("IB/core: Add helpers for uncached GID and P_Key searches")
Link: https://lore.kernel.org/r/e55d331b96cecfc2cf19803d16e7109ea966882d.1639055490.git.leonro@nvidia.com
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 6a585c3e21923..ffd0f43e2129f 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1039,7 +1039,8 @@ int ib_find_gid(struct ib_device *device, union ib_gid *gid,
 		for (i = 0; i < device->port_immutable[port].gid_tbl_len; ++i) {
 			ret = rdma_query_gid(device, port, i, &tmp_gid);
 			if (ret)
-				return ret;
+				continue;
+
 			if (!memcmp(&tmp_gid, gid, sizeof *gid)) {
 				*port_num = port;
 				if (index)
-- 
2.34.1