[PATCH] nfc: pn533: fix memcpy overflow warning

[Rosen Penev]

error: call to ‘__read_overflow2_field’ declared with attribute warning:
detected read beyond size of field (2nd parameter); maybe use
struct_group()? [-Werror=attribute-warning]

As suggested, add a struct_group and memcpy that.

Also replace 9 with sizeof for clarify.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
 drivers/nfc/pn533/pn533.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index d7bdbc82e2ba..4e721a8dfd8b 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -740,8 +740,10 @@ static int pn533_target_found_type_a(struct nfc_target *nfc_tgt, u8 *tgt_data,
 
 struct pn533_target_felica {
 	u8 pol_res;
-	u8 opcode;
-	u8 nfcid2[NFC_NFCID2_MAXSIZE];
+	struct_group(sensf_res,
+		u8 opcode;
+		u8 nfcid2[NFC_NFCID2_MAXSIZE];
+	);
 	u8 pad[8];
 	/* optional */
 	u8 syst_code[];
@@ -778,8 +780,8 @@ static int pn533_target_found_felica(struct nfc_target *nfc_tgt, u8 *tgt_data,
 	else
 		nfc_tgt->supported_protocols = NFC_PROTO_FELICA_MASK;
 
-	memcpy(nfc_tgt->sensf_res, &tgt_felica->opcode, 9);
-	nfc_tgt->sensf_res_len = 9;
+	memcpy(nfc_tgt->sensf_res, &tgt_felica->sensf_res, sizeof(tgt_felica->sensf_res));
+	nfc_tgt->sensf_res_len = sizeof(tgt_felica->sensf_res);
 
 	memcpy(nfc_tgt->nfcid2, tgt_felica->nfcid2, NFC_NFCID2_MAXSIZE);
 	nfc_tgt->nfcid2_len = NFC_NFCID2_MAXSIZE;
-- 
2.54.0