[PATCH v3 4/6] scsi: megaraid_sas: Replace one-element array with flexible-array member in MR_PD_CFG_SEQ_NUM_SYNC

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

One-element arrays are deprecated, and we are replacing them with
flexible array members, instead. So, replace one-element array with
flexible-array member in struct MR_PD_CFG_SEQ_NUM_SYNC and refactor
the rest of the code accordingly.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays [0].

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Link: Link: https://reviews.llvm.org/D126864 [0]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
Changes in v3:
 - Revert use of struct_size() helper.

Changes in v2:
 - None.

 drivers/scsi/megaraid/megaraid_sas_base.c   | 4 ++--
 drivers/scsi/megaraid/megaraid_sas_fusion.c | 2 +-
 drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index c06a346a3eaf..2dabe0b4823e 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -5795,7 +5795,7 @@ megasas_setup_jbod_map(struct megasas_instance *instance)
 	u32 pd_seq_map_sz;
 
 	pd_seq_map_sz = sizeof(struct MR_PD_CFG_SEQ_NUM_SYNC) +
-		(sizeof(struct MR_PD_CFG_SEQ) * (MAX_PHYSICAL_DEVICES - 1));
+		(sizeof(struct MR_PD_CFG_SEQ) * MAX_PHYSICAL_DEVICES);
 
 	instance->use_seqnum_jbod_fp =
 		instance->support_seqnum_jbod_fp;
@@ -8048,7 +8048,7 @@ static void megasas_detach_one(struct pci_dev *pdev)
 		megasas_release_fusion(instance);
 		pd_seq_map_sz = sizeof(struct MR_PD_CFG_SEQ_NUM_SYNC) +
 				(sizeof(struct MR_PD_CFG_SEQ) *
-					(MAX_PHYSICAL_DEVICES - 1));
+					MAX_PHYSICAL_DEVICES);
 		for (i = 0; i < 2 ; i++) {
 			if (fusion->ld_map[i])
 				dma_free_coherent(&instance->pdev->dev,
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index e48d4261d0bc..f17ec83f7c98 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -1310,7 +1310,7 @@ megasas_sync_pd_seq_num(struct megasas_instance *instance, bool pend) {
 
 	pd_sync = (void *)fusion->pd_seq_sync[(instance->pd_seq_map_id & 1)];
 	pd_seq_h = fusion->pd_seq_phys[(instance->pd_seq_map_id & 1)];
-	pd_seq_map_sz = struct_size(pd_sync, seq, MAX_PHYSICAL_DEVICES - 1);
+	pd_seq_map_sz = struct_size(pd_sync, seq, MAX_PHYSICAL_DEVICES);
 
 	cmd = megasas_get_cmd(instance);
 	if (!cmd) {
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
index df92d4369e04..49e9a9048ee7 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
@@ -1249,7 +1249,7 @@ struct MR_PD_CFG_SEQ {
 struct MR_PD_CFG_SEQ_NUM_SYNC {
 	__le32 size;
 	__le32 count;
-	struct MR_PD_CFG_SEQ seq[1];
+	struct MR_PD_CFG_SEQ seq[];
 } __packed;
 
 /* stream detection */
-- 
2.34.1