From: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
[ Upstream commit ed408529679737a9a7ad816c8de5d59ba104bb11 ]
smatch gives the warning:
drivers/infiniband/ulp/rtrs/rtrs-srv.c:1805 rtrs_rdma_connect() warn: passing zero to 'PTR_ERR'
Which is trying to say smatch has shown that srv is not an error pointer
and thus cannot be passed to PTR_ERR.
The solution is to move the list_add() down after full initilization of
rtrs_srv. To avoid holding the srv_mutex too long, only hold it during the
list operation as suggested by Leon.
Fixes: 03e9b33a0fd6 ("RDMA/rtrs: Only allow addition of path to an already established session")
Link: https://lore.kernel.org/r/20210216143807.65923-1-jinpu.wang@xxxxxxxxxxxxxxx
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/infiniband/ulp/rtrs/rtrs-srv.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
index 717304c49d0c3..f009a6907169c 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
@@ -1364,21 +1364,18 @@ static struct rtrs_srv *get_or_create_srv(struct rtrs_srv_ctx *ctx,
return srv;
}
}
+ mutex_unlock(&ctx->srv_mutex);
/*
* If this request is not the first connection request from the
* client for this session then fail and return error.
*/
- if (!first_conn) {
- mutex_unlock(&ctx->srv_mutex);
+ if (!first_conn)
return ERR_PTR(-ENXIO);
- }
/* need to allocate a new srv */
srv = kzalloc(sizeof(*srv), GFP_KERNEL);
- if (!srv) {
- mutex_unlock(&ctx->srv_mutex);
+ if (!srv)
return ERR_PTR(-ENOMEM);
- }
INIT_LIST_HEAD(&srv->paths_list);
mutex_init(&srv->paths_mutex);
@@ -1388,8 +1385,6 @@ static struct rtrs_srv *get_or_create_srv(struct rtrs_srv_ctx *ctx,
srv->ctx = ctx;
device_initialize(&srv->dev);
srv->dev.release = rtrs_srv_dev_release;
- list_add(&srv->ctx_list, &ctx->srv_list);
- mutex_unlock(&ctx->srv_mutex);
srv->chunks = kcalloc(srv->queue_depth, sizeof(*srv->chunks),
GFP_KERNEL);
@@ -1402,6 +1397,9 @@ static struct rtrs_srv *get_or_create_srv(struct rtrs_srv_ctx *ctx,
goto err_free_chunks;
}
refcount_set(&srv->refcount, 1);
+ mutex_lock(&ctx->srv_mutex);
+ list_add(&srv->ctx_list, &ctx->srv_list);
+ mutex_unlock(&ctx->srv_mutex);
return srv;
@@ -1816,11 +1814,7 @@ static int rtrs_rdma_connect(struct rdma_cm_id *cm_id,
}
recon_cnt = le16_to_cpu(msg->recon_cnt);
srv = get_or_create_srv(ctx, &msg->paths_uuid, msg->first_conn);
- /*
- * "refcount == 0" happens if a previous thread calls get_or_create_srv
- * allocate srv, but chunks of srv are not allocated yet.
- */
- if (IS_ERR(srv) || refcount_read(&srv->refcount) == 0) {
+ if (IS_ERR(srv)) {
err = PTR_ERR(srv);
goto reject_w_err;
}
--
2.27.0
