Re: [PATCH] IB/srpt: Fix passing zero to 'PTR_ERR'

[Jason Gunthorpe]

On Thu, Nov 12, 2020 at 10:54:43PM +0800, YueHaibing wrote:
> Fix smatch warning:
> 
> drivers/infiniband/ulp/srpt/ib_srpt.c:2341 srpt_cm_req_recv() warn: passing 
> zero to 'PTR_ERR'
> 
> Use PTR_ERR_OR_ZERO instead of PTR_ERR
> 
> Fixes: 847462de3a0a ("IB/srpt: Fix srpt_cm_req_recv() error path (1/2)")
> Signed-off-by: YueHaibing <yuehaib...@huawei.com>
>  drivers/infiniband/ulp/srpt/ib_srpt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c 
> b/drivers/infiniband/ulp/srpt/ib_srpt.c
> index 6be60aa5ffe2..3ff24b5048ac 100644
> +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
> @@ -2338,7 +2338,7 @@ static int srpt_cm_req_recv(struct srpt_device *const 
> sdev,
>  
>       if (IS_ERR_OR_NULL(ch->sess)) {
>               WARN_ON_ONCE(ch->sess == NULL);
> -             ret = PTR_ERR(ch->sess);
> +             ret = PTR_ERR_OR_ZERO(ch->sess);
>               ch->sess = NULL;
>               pr_info("Rejected login for initiator %s: ret = %d.\n",
>                       ch->sess_name, ret);

I think it should be like this, Bart?

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c 
b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 6017d525084a0c..80f9673956ced2 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2311,7 +2311,7 @@ static int srpt_cm_req_recv(struct srpt_device *const 
sdev,
 
        mutex_lock(&sport->port_guid_id.mutex);
        list_for_each_entry(stpg, &sport->port_guid_id.tpg_list, entry) {
-               if (!IS_ERR_OR_NULL(ch->sess))
+               if (ch->sess)
                        break;
                ch->sess = target_setup_session(&stpg->tpg, tag_num,
                                                tag_size, TARGET_PROT_NORMAL,
@@ -2321,12 +2321,12 @@ static int srpt_cm_req_recv(struct srpt_device *const 
sdev,
 
        mutex_lock(&sport->port_gid_id.mutex);
        list_for_each_entry(stpg, &sport->port_gid_id.tpg_list, entry) {
-               if (!IS_ERR_OR_NULL(ch->sess))
+               if (ch->sess)
                        break;
                ch->sess = target_setup_session(&stpg->tpg, tag_num,
                                        tag_size, TARGET_PROT_NORMAL, i_port_id,
                                        ch, NULL);
-               if (!IS_ERR_OR_NULL(ch->sess))
+               if (ch->sess)
                        break;
                /* Retry without leading "0x" */
                ch->sess = target_setup_session(&stpg->tpg, tag_num,
@@ -2335,7 +2335,9 @@ static int srpt_cm_req_recv(struct srpt_device *const 
sdev,
        }
        mutex_unlock(&sport->port_gid_id.mutex);
 
-       if (IS_ERR_OR_NULL(ch->sess)) {
+       if (!ch->sess)
+               ch->sess = ERR_PTR(-ENOENT);
+       if (IS_ERR(ch->sess)) {
                WARN_ON_ONCE(ch->sess == NULL);
                ret = PTR_ERR(ch->sess);
                ch->sess = NULL;