[PATCH 4.4 68/78] scsi: fcoe: Embed fc_rport_priv in fcoe_rport structure

Greg Kroah-Hartman
2019-08-22T17:46:10Z

From: Hannes Reinecke <hare@suse.de>

commit 023358b136d490ca91735ac6490db3741af5a8bd upstream.

Gcc-9 complains for a memset across pointer boundaries, which happens as
the code tries to allocate a flexible array on the stack. Turns out we
cannot do this without relying on gcc-isms, so with this patch we'll embed
the fc_rport_priv structure into fcoe_rport, can use the normal
'container_of' outcast, and will only have to do a memset over one
structure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/fcoe/fcoe_ctlr.c | 33 ++++++++++++++-------------------
drivers/scsi/libfc/fc_rport.c | 5 ++++-
include/scsi/libfcoe.h | 1 +
3 files changed, 19 insertions(+), 20 deletions(-)

--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -1973,7 +1973,7 @@ EXPORT_SYMBOL_GPL(fcoe_wwn_from_mac);
*/
static inline struct fcoe_rport *fcoe_ctlr_rport(struct fc_rport_priv *rdata)
{
- return (struct fcoe_rport *)(rdata + 1);
+ return container_of(rdata, struct fcoe_rport, rdata);
}

/**
@@ -2233,7 +2233,7 @@ static void fcoe_ctlr_vn_start(struct fc
*/
static int fcoe_ctlr_vn_parse(struct fcoe_ctlr *fip,
struct sk_buff *skb,
- struct fc_rport_priv *rdata)
+ struct fcoe_rport *frport)
{
struct fip_header *fiph;
struct fip_desc *desc = NULL;
@@ -2241,16 +2241,12 @@ static int fcoe_ctlr_vn_parse(struct fco
struct fip_wwn_desc *wwn = NULL;
struct fip_vn_desc *vn = NULL;
struct fip_size_desc *size = NULL;
- struct fcoe_rport *frport;
size_t rlen;
size_t dlen;
u32 desc_mask = 0;
u32 dtype;
u8 sub;

- memset(rdata, 0, sizeof(*rdata) + sizeof(*frport));
- frport = fcoe_ctlr_rport(rdata);
-
fiph = (struct fip_header *)skb->data;
frport->flags = ntohs(fiph->fip_flags);

@@ -2313,15 +2309,17 @@ static int fcoe_ctlr_vn_parse(struct fco
if (dlen != sizeof(struct fip_wwn_desc))
goto len_err;
wwn = (struct fip_wwn_desc *)desc;
- rdata->ids.node_name = get_unaligned_be64(&wwn->fd_wwn);
+ frport->rdata.ids.node_name =
+ get_unaligned_be64(&wwn->fd_wwn);
break;
case FIP_DT_VN_ID:
if (dlen != sizeof(struct fip_vn_desc))
goto len_err;
vn = (struct fip_vn_desc *)desc;
memcpy(frport->vn_mac, vn->fd_mac, ETH_ALEN);
- rdata->ids.port_id = ntoh24(vn->fd_fc_id);
- rdata->ids.port_name = get_unaligned_be64(&vn->fd_wwpn);
+ frport->rdata.ids.port_id = ntoh24(vn->fd_fc_id);
+ frport->rdata.ids.port_name =
+ get_unaligned_be64(&vn->fd_wwpn);
break;
case FIP_DT_FC4F:
if (dlen != sizeof(struct fip_fc4_feat))
@@ -2664,16 +2662,13 @@ static int fcoe_ctlr_vn_recv(struct fcoe
{
struct fip_header *fiph;
enum fip_vn2vn_subcode sub;
- struct {
- struct fc_rport_priv rdata;
- struct fcoe_rport frport;
- } buf;
+ struct fcoe_rport frport = { };
int rc;

fiph = (struct fip_header *)skb->data;
sub = fiph->fip_subcode;

- rc = fcoe_ctlr_vn_parse(fip, skb, &buf.rdata);
+ rc = fcoe_ctlr_vn_parse(fip, skb, &frport);
if (rc) {
LIBFCOE_FIP_DBG(fip, "vn_recv vn_parse error %d\n", rc);
goto drop;
@@ -2682,19 +2677,19 @@ static int fcoe_ctlr_vn_recv(struct fcoe
mutex_lock(&fip->ctlr_mutex);
switch (sub) {
case FIP_SC_VN_PROBE_REQ:
- fcoe_ctlr_vn_probe_req(fip, &buf.rdata);
+ fcoe_ctlr_vn_probe_req(fip, &frport.rdata);
break;
case FIP_SC_VN_PROBE_REP:
- fcoe_ctlr_vn_probe_reply(fip, &buf.rdata);
+ fcoe_ctlr_vn_probe_reply(fip, &frport.rdata);
break;
case FIP_SC_VN_CLAIM_NOTIFY:
- fcoe_ctlr_vn_claim_notify(fip, &buf.rdata);
+ fcoe_ctlr_vn_claim_notify(fip, &frport.rdata);
break;
case FIP_SC_VN_CLAIM_REP:
- fcoe_ctlr_vn_claim_resp(fip, &buf.rdata);
+ fcoe_ctlr_vn_claim_resp(fip, &frport.rdata);
break;
case FIP_SC_VN_BEACON:
- fcoe_ctlr_vn_beacon(fip, &buf.rdata);
+ fcoe_ctlr_vn_beacon(fip, &frport.rdata);
break;
default:
LIBFCOE_FIP_DBG(fip, "vn_recv unknown subcode %d\n", sub);
--- a/drivers/scsi/libfc/fc_rport.c
+++ b/drivers/scsi/libfc/fc_rport.c
@@ -121,12 +121,15 @@ static struct fc_rport_priv *fc_rport_cr
u32 port_id)
{
struct fc_rport_priv *rdata;
+ size_t rport_priv_size = sizeof(*rdata);

rdata = lport->tt.rport_lookup(lport, port_id);
if (rdata)
return rdata;

- rdata = kzalloc(sizeof(*rdata) + lport->rport_priv_size, GFP_KERNEL);
+ if (lport->rport_priv_size > 0)
+ rport_priv_size = lport->rport_priv_size;
+ rdata = kzalloc(rport_priv_size, GFP_KERNEL);
if (!rdata)
return NULL;

--- a/include/scsi/libfcoe.h
+++ b/include/scsi/libfcoe.h
@@ -236,6 +236,7 @@ struct fcoe_fcf {
* @vn_mac: VN_Node assigned MAC address for data
*/
struct fcoe_rport {
+ struct fc_rport_priv rdata;
unsigned long time;
u16 fcoe_len;
u16 flags;