[PATCH v2 4/4][next] scsi: megaraid_sas: Replace one-element array with flexible-array member in MR_PD_CFG_SEQ_NUM_SYNC

Gustavo A. R. Silva
2021-08-05T04:18:13Z

Replace one-element array with a flexible-array member in struct
MR_PD_CFG_SEQ_NUM_SYNC and use the struct_size() helper.

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().

Link: https://en.wikipedia.org/wiki/Flexible_array_member
Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
Changes in v2:
- None.

drivers/scsi/megaraid/megaraid_sas_base.c | 14 +++++++-------
drivers/scsi/megaraid/megaraid_sas_fusion.c | 2 +-
drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index d072f9caeb4a..a4131dd510e3 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -5782,10 +5782,10 @@ megasas_setup_jbod_map(struct megasas_instance *instance)
{
int i;
struct fusion_context *fusion = instance->ctrl_context;
- u32 pd_seq_map_sz;
+ size_t 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));
+ pd_seq_map_sz = struct_size((struct MR_PD_CFG_SEQ_NUM_SYNC *)0, seq,
+ MAX_PHYSICAL_DEVICES);

instance->use_seqnum_jbod_fp =
instance->support_seqnum_jbod_fp;
@@ -7961,7 +7961,7 @@ static void megasas_detach_one(struct pci_dev *pdev)
struct Scsi_Host *host;
struct megasas_instance *instance;
struct fusion_context *fusion;
- u32 pd_seq_map_sz;
+ size_t pd_seq_map_sz;

instance = pci_get_drvdata(pdev);

@@ -8033,9 +8033,9 @@ static void megasas_detach_one(struct pci_dev *pdev)

if (instance->adapter_type != MFI_SERIES) {
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));
+ pd_seq_map_sz =
+ struct_size((struct MR_PD_CFG_SEQ_NUM_SYNC *)0,
+ seq, 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 06399c026a8d..a824fb641fda 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 5fe2f7a6eebe..af39d9c20cc6 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 */
--
2.27.0