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, 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
https://github.com/ClangBuiltLinux/linux/issues/1590
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
Changes in v2:
 - Revert changes for _port_ due to protocol definition conflict.
   Link: https://lore.kernel.org/lkml/22139a80-3f64-1f21-6b5c-65d250bafe09@linux.ibm.com/
 - Update subject line.
 - Update changelog text.

 drivers/scsi/libfc/fc_encode.h | 2 +-
 include/scsi/fc/fc_ms.h        | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/libfc/fc_encode.h b/drivers/scsi/libfc/fc_encode.h
index 74ae7fd15d8d..7dcac3b6baa7 100644
--- a/drivers/scsi/libfc/fc_encode.h
+++ b/drivers/scsi/libfc/fc_encode.h
@@ -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..56a5d2b5a624 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__));
 
 /*
-- 
2.27.0

On Mon, 14 Feb 2022 16:39:03 -0600, Gustavo A. R. Silva wrote:

> 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, 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().
> 
> [...]

Applied to 5.18/scsi-queue, thanks!

[1/1] scsi: fc: Replace one-element arrays with flexible-array members
      https://git.kernel.org/mkp/scsi/c/c5b483d5c1a2

-- 
Martin K. Petersen	Oracle Linux Engineering

Gustavo,

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

Applied to 5.18/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering