From: Jack Wang jinpu.wang@cloud.ionos.com
[ 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@cloud.ionos.com Reported-by: kernel test robot lkp@intel.com Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Jack Wang jinpu.wang@cloud.ionos.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 77ec87f1a660b..3850d2a938f8e 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c @@ -1348,21 +1348,18 @@ 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); @@ -1372,8 +1369,6 @@ 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); @@ -1386,6 +1381,9 @@ 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;
@@ -1800,11 +1798,7 @@ 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; }