[PATCH][next] scsi: Replace one-element arrays with flexible-array members

From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: "James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Hannes Reinecke <hare@suse.de>
Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	linux-hardening@vger.kernel.org,
	Kees Cook <keescook@chromium.org>
Subject: [PATCH][next] scsi: Replace one-element arrays with flexible-array members
Date: Fri, 5 Nov 2021 04:11:02 -0500	[thread overview]
Message-ID: <20211105091102.GA126301@embeddedor> (raw)

Use flexible-array members in struct fc_fdmi_attr_entry and
fs_fdmi_attrs instead of one-element arrays, and refactor the
code accordingly.

Also, turn the one-element array _port_ in struct fc_fdmi_rpl
into a simple object of type struct fc_fdmi_port_name, as it
seems there is no more than just one port expected:

$ git grep -nw numport drivers/scsi/
drivers/scsi/csiostor/csio_lnode.c:447: reg_pl->numport = htonl(1);
drivers/scsi/libfc/fc_encode.h:232:             put_unaligned_be32(1, &ct->payload.rhba.port.numport);

Also, this helps with the ongoing efforts to globally enable
-Warray-bounds and get us closer to being able to tighten the
FORTIFY_SOURCE routines on memcpy().

https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/scsi/csiostor/csio_lnode.c | 2 +-
 drivers/scsi/libfc/fc_encode.h     | 4 ++--
 include/scsi/fc/fc_ms.h            | 6 +++---
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/csiostor/csio_lnode.c b/drivers/scsi/csiostor/csio_lnode.c
index d5ac93897023..cf9dd79ee488 100644
--- a/drivers/scsi/csiostor/csio_lnode.c
+++ b/drivers/scsi/csiostor/csio_lnode.c
@@ -445,7 +445,7 @@ csio_ln_fdmi_dprt_cbfn(struct csio_hw *hw, struct csio_ioreq *fdmi_req)
 	/* Register one port per hba */
 	reg_pl = (struct fc_fdmi_rpl *)pld;
 	reg_pl->numport = htonl(1);
-	memcpy(&reg_pl->port[0].portname, csio_ln_wwpn(ln), 8);
+	memcpy(&reg_pl->port.portname, csio_ln_wwpn(ln), 8);
 	pld += sizeof(*reg_pl);
 
 	/* Start appending HBA attributes hba */
diff --git a/drivers/scsi/libfc/fc_encode.h b/drivers/scsi/libfc/fc_encode.h
index 74ae7fd15d8d..5806f99e4061 100644
--- a/drivers/scsi/libfc/fc_encode.h
+++ b/drivers/scsi/libfc/fc_encode.h
@@ -232,7 +232,7 @@ static inline int fc_ct_ms_fill(struct fc_lport *lport,
 		put_unaligned_be32(1, &ct->payload.rhba.port.numport);
 		/* Port Name */
 		put_unaligned_be64(lport->wwpn,
-				   &ct->payload.rhba.port.port[0].portname);
+				   &ct->payload.rhba.port.port.portname);
 
 		/* HBA Attributes */
 		put_unaligned_be32(numattrs,
@@ -246,7 +246,7 @@ static inline int fc_ct_ms_fill(struct fc_lport *lport,
 				   &entry->type);
 		put_unaligned_be16(len, &entry->len);
 		put_unaligned_be64(lport->wwnn,
-				   (__be64 *)&entry->value[0]);
+				   (__be64 *)&entry->value);
 
 		/* Manufacturer */
 		entry = (struct fc_fdmi_attr_entry *)((char *)entry->value +
diff --git a/include/scsi/fc/fc_ms.h b/include/scsi/fc/fc_ms.h
index 00191695233a..44fbe84fa664 100644
--- a/include/scsi/fc/fc_ms.h
+++ b/include/scsi/fc/fc_ms.h
@@ -158,7 +158,7 @@ struct fc_fdmi_port_name {
 struct fc_fdmi_attr_entry {
 	__be16		type;
 	__be16		len;
-	__u8		value[1];
+	__u8		value[];
 } __attribute__((__packed__));
 
 /*
@@ -166,7 +166,7 @@ struct fc_fdmi_attr_entry {
  */
 struct fs_fdmi_attrs {
 	__be32				numattrs;
-	struct fc_fdmi_attr_entry	attr[1];
+	struct fc_fdmi_attr_entry	attr[];
 } __attribute__((__packed__));
 
 /*
@@ -174,7 +174,7 @@ struct fs_fdmi_attrs {
  */
 struct fc_fdmi_rpl {
 	__be32				numport;
-	struct fc_fdmi_port_name	port[1];
+	struct fc_fdmi_port_name	port;
 } __attribute__((__packed__));
 
 /*
-- 
2.27.0

