[PATCH 3/6] scsi: mpt3sas: Use struct_size() for struct size calculations

[James Seo]

After converting variable-length arrays to flexible array members,
use the bounds-checking struct_size() helper when possible to avoid
open-coded arithmetic struct size calculations.

Signed-off-by: James Seo <james@xxxxxxxxxx>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c      |  3 +--
 drivers/scsi/mpt3sas/mpt3sas_scsih.c     | 18 ++++++------------
 drivers/scsi/mpt3sas/mpt3sas_transport.c |  9 +++------
 drivers/scsi/mpt3sas/mpt3sas_warpdrive.c |  3 +--
 4 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 53f5492579cb..2ae0185938f3 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -4876,8 +4876,7 @@ mpt3sas_base_update_missing_delay(struct MPT3SAS_ADAPTER *ioc,
 	if (!num_phys)
 		return;
 
-	sz = offsetof(Mpi2SasIOUnitPage1_t, PhyData) + (num_phys *
-	    sizeof(Mpi2SasIOUnit1PhyData_t));
+	sz = struct_size(sas_iounit_pg1, PhyData, num_phys);
 	sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg1) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index c3c1f466fe01..d5426a520a77 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -2431,8 +2431,7 @@ _scsih_get_volume_capabilities(struct MPT3SAS_ADAPTER *ioc,
 	}
 
 	raid_device->num_pds = num_pds;
-	sz = offsetof(Mpi2RaidVolPage0_t, PhysDisk) + (num_pds *
-	    sizeof(Mpi2RaidVol0PhysDisk_t));
+	sz = struct_size(vol_pg0, PhysDisk, num_pds);
 	vol_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!vol_pg0) {
 		dfailprintk(ioc,
@@ -5966,8 +5965,7 @@ _scsih_update_vphys_after_reset(struct MPT3SAS_ADAPTER *ioc)
 	/*
 	 * Read SASIOUnitPage0 to get each HBA Phy's data.
 	 */
-	sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) +
-	    (ioc->sas_hba.num_phys * sizeof(Mpi2SasIOUnit0PhyData_t));
+	sz = struct_size(sas_iounit_pg0, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg0) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
@@ -6145,8 +6143,7 @@ _scsih_get_port_table_after_reset(struct MPT3SAS_ADAPTER *ioc,
 	u64 attached_sas_addr;
 	u8 found = 0, port_count = 0, port_id;
 
-	sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) + (ioc->sas_hba.num_phys
-	    * sizeof(Mpi2SasIOUnit0PhyData_t));
+	sz = struct_size(sas_iounit_pg0, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg0) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
@@ -6579,8 +6576,7 @@ _scsih_sas_host_refresh(struct MPT3SAS_ADAPTER *ioc)
 		  ioc_info(ioc, "updating handles for sas_host(0x%016llx)\n",
 			   (u64)ioc->sas_hba.sas_address));
 
-	sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) + (ioc->sas_hba.num_phys
-	    * sizeof(Mpi2SasIOUnit0PhyData_t));
+	sz = struct_size(sas_iounit_pg0, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg0) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
@@ -6731,8 +6727,7 @@ _scsih_sas_host_add(struct MPT3SAS_ADAPTER *ioc)
 	ioc->sas_hba.num_phys = num_phys;
 
 	/* sas_iounit page 0 */
-	sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) + (ioc->sas_hba.num_phys *
-	    sizeof(Mpi2SasIOUnit0PhyData_t));
+	sz = struct_size(sas_iounit_pg0, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg0) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
@@ -6754,8 +6749,7 @@ _scsih_sas_host_add(struct MPT3SAS_ADAPTER *ioc)
 	}
 
 	/* sas_iounit page 1 */
-	sz = offsetof(Mpi2SasIOUnitPage1_t, PhyData) + (ioc->sas_hba.num_phys *
-	    sizeof(Mpi2SasIOUnit1PhyData_t));
+	sz = struct_size(sas_iounit_pg1, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg1) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
diff --git a/drivers/scsi/mpt3sas/mpt3sas_transport.c b/drivers/scsi/mpt3sas/mpt3sas_transport.c
index e8a4750f6ec4..421ea511b664 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_transport.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_transport.c
@@ -1792,8 +1792,7 @@ _transport_phy_enable(struct sas_phy *phy, int enable)
 	/* handle hba phys */
 
 	/* read sas_iounit page 0 */
-	sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) + (ioc->sas_hba.num_phys *
-	    sizeof(Mpi2SasIOUnit0PhyData_t));
+	sz = struct_size(sas_iounit_pg0, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg0) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
@@ -1833,8 +1832,7 @@ _transport_phy_enable(struct sas_phy *phy, int enable)
 	}
 
 	/* read sas_iounit page 1 */
-	sz = offsetof(Mpi2SasIOUnitPage1_t, PhyData) + (ioc->sas_hba.num_phys *
-	    sizeof(Mpi2SasIOUnit1PhyData_t));
+	sz = struct_size(sas_iounit_pg1, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg1) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
@@ -1944,8 +1942,7 @@ _transport_phy_speed(struct sas_phy *phy, struct sas_phy_linkrates *rates)
 	/* handle hba phys */
 
 	/* sas_iounit page 1 */
-	sz = offsetof(Mpi2SasIOUnitPage1_t, PhyData) + (ioc->sas_hba.num_phys *
-	    sizeof(Mpi2SasIOUnit1PhyData_t));
+	sz = struct_size(sas_iounit_pg1, PhyData, ioc->sas_hba.num_phys);
 	sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL);
 	if (!sas_iounit_pg1) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
diff --git a/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c b/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c
index cc07ba41f507..1d64e5056a8a 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c
@@ -141,8 +141,7 @@ mpt3sas_init_warpdrive_properties(struct MPT3SAS_ADAPTER *ioc,
 		return;
 	}
 
-	sz = offsetof(Mpi2RaidVolPage0_t, PhysDisk) + (num_pds *
-	    sizeof(Mpi2RaidVol0PhysDisk_t));
+	sz = struct_size(vol_pg0, PhysDisk, num_pds);
 	vol_pg0 = kzalloc(sz, GFP_KERNEL);
 	if (!vol_pg0) {
 		ioc_info(ioc, "WarpDrive : Direct IO is disabled Memory allocation failure for RVPG0\n");
-- 
2.39.2