scsi: mpt3sas: Use flexible arrays when obviously possible

These terminal 1-length variable arrays can be directly converted into C99
flexible array members without any binary changes.

In most cases, they belong to unused structs, or to structs used only by
unused code. The remaining few coincidentally have their sizes calculated
in roundabout ways that do not depend on the sizeof() their structs.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Seo <james@equiv.tech>
Link: https://lore.kernel.org/r/20230806170604.16143-2-james@equiv.techTested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpi/mpi2_image.h

@@ -295,20 +295,9 @@ typedef struct _MPI2_EXT_IMAGE_HEADER {
 /*FLASH Layout Extended Image Data */
 
 /*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check RegionsPerLayout at runtime.
+ *Host code (drivers, BIOS, utilities, etc.) should check NumberOfLayouts and
+ *RegionsPerLayout at runtime before using Layout[] and Region[].
  */
-#ifndef MPI2_FLASH_NUMBER_OF_REGIONS
-#define MPI2_FLASH_NUMBER_OF_REGIONS        (1)
-#endif
-
-/*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check NumberOfLayouts at runtime.
- */
-#ifndef MPI2_FLASH_NUMBER_OF_LAYOUTS
-#define MPI2_FLASH_NUMBER_OF_LAYOUTS        (1)
-#endif
 
 typedef struct _MPI2_FLASH_REGION {
 	U8 RegionType;		/*0x00 */
@@ -325,7 +314,7 @@ typedef struct _MPI2_FLASH_LAYOUT {
 	U32 Reserved1;		/*0x04 */
 	U32 Reserved2;		/*0x08 */
 	U32 Reserved3;		/*0x0C */
-	MPI2_FLASH_REGION Region[MPI2_FLASH_NUMBER_OF_REGIONS];	/*0x10 */
+	MPI2_FLASH_REGION Region[];	/*0x10 */
 } MPI2_FLASH_LAYOUT, *PTR_MPI2_FLASH_LAYOUT,
 	Mpi2FlashLayout_t, *pMpi2FlashLayout_t;
 
@@ -339,7 +328,7 @@ typedef struct _MPI2_FLASH_LAYOUT_DATA {
 	U16 MinimumSectorAlignment;	/*0x08 */
 	U16 Reserved3;		/*0x0A */
 	U32 Reserved4;		/*0x0C */
-	MPI2_FLASH_LAYOUT Layout[MPI2_FLASH_NUMBER_OF_LAYOUTS];	/*0x10 */
+	MPI2_FLASH_LAYOUT Layout[];	/*0x10 */
 } MPI2_FLASH_LAYOUT_DATA, *PTR_MPI2_FLASH_LAYOUT_DATA,
 	Mpi2FlashLayoutData_t, *pMpi2FlashLayoutData_t;
 
@@ -373,12 +362,9 @@ typedef struct _MPI2_FLASH_LAYOUT_DATA {
 /*Supported Devices Extended Image Data */
 
 /*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check NumberOfDevices at runtime.
+ *Host code (drivers, BIOS, utilities, etc.) should check NumberOfDevices at
+ *runtime before using SupportedDevice[].
  */
-#ifndef MPI2_SUPPORTED_DEVICES_IMAGE_NUM_DEVICES
-#define MPI2_SUPPORTED_DEVICES_IMAGE_NUM_DEVICES    (1)
-#endif
 
 typedef struct _MPI2_SUPPORTED_DEVICE {
 	U16 DeviceID;		/*0x00 */
@@ -399,7 +385,7 @@ typedef struct _MPI2_SUPPORTED_DEVICES_DATA {
 	U8 Reserved2;		/*0x03 */
 	U32 Reserved3;		/*0x04 */
 	MPI2_SUPPORTED_DEVICE
-	SupportedDevice[MPI2_SUPPORTED_DEVICES_IMAGE_NUM_DEVICES];/*0x08 */
+	SupportedDevice[];	/*0x08 */
 } MPI2_SUPPORTED_DEVICES_DATA, *PTR_MPI2_SUPPORTED_DEVICES_DATA,
 	Mpi2SupportedDevicesData_t, *pMpi2SupportedDevicesData_t;
 
@@ -464,7 +450,7 @@ typedef struct _MPI25_ENCRYPTED_HASH_ENTRY {
 	U8		EncryptionAlgorithm;	/*0x02 */
 	U8		Reserved1;		/*0x03 */
 	U32		Reserved2;		/*0x04 */
-	U32		EncryptedHash[1];	/*0x08 */ /* variable length */
+	U32		EncryptedHash[];	/*0x08 */
 } MPI25_ENCRYPTED_HASH_ENTRY, *PTR_MPI25_ENCRYPTED_HASH_ENTRY,
 Mpi25EncryptedHashEntry_t, *pMpi25EncryptedHashEntry_t;
 
@@ -508,7 +494,7 @@ typedef struct _MPI25_ENCRYPTED_HASH_DATA {
 	U8				NumHash;		/*0x01 */
 	U16				Reserved1;		/*0x02 */
 	U32				Reserved2;		/*0x04 */
-	MPI25_ENCRYPTED_HASH_ENTRY	EncryptedHashEntry[1];  /*0x08 */
+	MPI25_ENCRYPTED_HASH_ENTRY	EncryptedHashEntry[];	/*0x08 */
 } MPI25_ENCRYPTED_HASH_DATA, *PTR_MPI25_ENCRYPTED_HASH_DATA,
 Mpi25EncryptedHashData_t, *pMpi25EncryptedHashData_t;
 

drivers/scsi/mpt3sas/mpi/mpi2_ioc.h

@@ -808,12 +808,9 @@ typedef struct _MPI2_EVENT_DATA_IR_PHYSICAL_DISK {
 /*Integrated RAID Configuration Change List Event data */
 
 /*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check NumElements at runtime.
+ *Host code (drivers, BIOS, utilities, etc.) should check NumElements at
+ *runtime before using ConfigElement[].
  */
-#ifndef MPI2_EVENT_IR_CONFIG_ELEMENT_COUNT
-#define MPI2_EVENT_IR_CONFIG_ELEMENT_COUNT          (1)
-#endif
 
 typedef struct _MPI2_EVENT_IR_CONFIG_ELEMENT {
 	U16 ElementFlags;	/*0x00 */
@@ -848,7 +845,7 @@ typedef struct _MPI2_EVENT_DATA_IR_CONFIG_CHANGE_LIST {
 	U8 ConfigNum;		/*0x03 */
 	U32 Flags;		/*0x04 */
 	MPI2_EVENT_IR_CONFIG_ELEMENT
-		ConfigElement[MPI2_EVENT_IR_CONFIG_ELEMENT_COUNT];/*0x08 */
+		ConfigElement[];/*0x08 */
 } MPI2_EVENT_DATA_IR_CONFIG_CHANGE_LIST,
 	*PTR_MPI2_EVENT_DATA_IR_CONFIG_CHANGE_LIST,
 	Mpi2EventDataIrConfigChangeList_t,
@@ -969,12 +966,9 @@ typedef struct _MPI2_EVENT_DATA_SAS_INIT_TABLE_OVERFLOW {
 /*SAS Topology Change List Event data */
 
 /*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check NumEntries at runtime.
+ *Host code (drivers, BIOS, utilities, etc.) should check NumEntries at
+ *runtime before using PHY[].
  */
-#ifndef MPI2_EVENT_SAS_TOPO_PHY_COUNT
-#define MPI2_EVENT_SAS_TOPO_PHY_COUNT           (1)
-#endif
 
 typedef struct _MPI2_EVENT_SAS_TOPO_PHY_ENTRY {
 	U16 AttachedDevHandle;	/*0x00 */
@@ -994,7 +988,7 @@ typedef struct _MPI2_EVENT_DATA_SAS_TOPOLOGY_CHANGE_LIST {
 	U8 ExpStatus;		/*0x0A */
 	U8 PhysicalPort;	/*0x0B */
 	MPI2_EVENT_SAS_TOPO_PHY_ENTRY
-	PHY[MPI2_EVENT_SAS_TOPO_PHY_COUNT];	/*0x0C */
+	PHY[];			/*0x0C */
 } MPI2_EVENT_DATA_SAS_TOPOLOGY_CHANGE_LIST,
 	*PTR_MPI2_EVENT_DATA_SAS_TOPOLOGY_CHANGE_LIST,
 	Mpi2EventDataSasTopologyChangeList_t,
@@ -1229,12 +1223,9 @@ typedef struct _MPI26_EVENT_DATA_PCIE_ENUMERATION {
 /*PCIe Topology Change List Event data (MPI v2.6 and later) */
 
 /*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check NumEntries at runtime.
+ *Host code (drivers, BIOS, utilities, etc.) should check NumEntries at
+ *runtime before using PortEntry[].
  */
-#ifndef MPI26_EVENT_PCIE_TOPO_PORT_COUNT
-#define MPI26_EVENT_PCIE_TOPO_PORT_COUNT        (1)
-#endif
 
 typedef struct _MPI26_EVENT_PCIE_TOPO_PORT_ENTRY {
 	U16	AttachedDevHandle;      /*0x00 */
@@ -1286,7 +1277,7 @@ typedef struct _MPI26_EVENT_DATA_PCIE_TOPOLOGY_CHANGE_LIST {
 	U8	SwitchStatus;           /*0x0A */
 	U8	PhysicalPort;           /*0x0B */
 	MPI26_EVENT_PCIE_TOPO_PORT_ENTRY
-		PortEntry[MPI26_EVENT_PCIE_TOPO_PORT_COUNT]; /*0x0C */
+		PortEntry[];            /*0x0C */
 } MPI26_EVENT_DATA_PCIE_TOPOLOGY_CHANGE_LIST,
 	*PTR_MPI26_EVENT_DATA_PCIE_TOPOLOGY_CHANGE_LIST,
 	Mpi26EventDataPCIeTopologyChangeList_t,