[lvc-project] [PATCH v2] usb: storage: isd200: fix sloppy typing in isd200_scsi_to_ata()

[Sergey Shtylyov]

When isd200_scsi_to_ata() emulates the SCSI READ/WRITE (10) commands,
the LBA is a 32-bit CDB field and the transfer length is a 16-bit CDB
field, so using *unsigned long* (which is 32-bit type on the 32-bit
arches and 64-bit type on the 64-bit arches) to declare the lba and
blockCount variables doesn't make much sense.  Also, when it emulates
the READ CAPACITY command, the returned LBA is a 32-bit parameter data
field and the ATA device CHS mode capacity fits into 32 bits as well,
so using *unsigned long* to declare the capacity variable doesn't make
much sense as well. Let's use the u16/u32 types for those variables...

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov at omp.ru>

---
This patch is against the 'usb-next' branch of Greg KH's usb.git repo...

Changes in version 2:
- fixed up the lba and blockCount variable declarations;
- removed the typecasts from the blockCount variable calculation;
- undid the reordering of the capacity variable declaration;
- completely rewrote the patch description.

 drivers/usb/storage/isd200.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Index: usb/drivers/usb/storage/isd200.c
===================================================================
--- usb.orig/drivers/usb/storage/isd200.c
+++ usb/drivers/usb/storage/isd200.c
@@ -1232,8 +1232,8 @@ static int isd200_scsi_to_ata(struct scs
 	int sendToTransport = 1;
 	unsigned char sectnum, head;
 	unsigned short cylinder;
-	unsigned long lba;
-	unsigned long blockCount;
+	u32 lba;
+	u16 blockCount;
 	unsigned char senseData[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
 
 	memset(ataCdb, 0, sizeof(union ata_cdb));
@@ -1291,7 +1291,7 @@ static int isd200_scsi_to_ata(struct scs
 
 	case READ_CAPACITY:
 	{
-		unsigned long capacity;
+		u32 capacity;
 		struct read_capacity_data readCapacityData;
 
 		usb_stor_dbg(us, "   ATA OUT - SCSIOP_READ_CAPACITY\n");
@@ -1316,7 +1316,7 @@ static int isd200_scsi_to_ata(struct scs
 		usb_stor_dbg(us, "   ATA OUT - SCSIOP_READ\n");
 
 		lba = be32_to_cpu(*(__be32 *)&srb->cmnd[2]);
-		blockCount = (unsigned long)srb->cmnd[7]<<8 | (unsigned long)srb->cmnd[8];
+		blockCount = srb->cmnd[7] << 8 | srb->cmnd[8];
 
 		if (ata_id_has_lba(id)) {
 			sectnum = (unsigned char)(lba);
@@ -1348,7 +1348,7 @@ static int isd200_scsi_to_ata(struct scs
 		usb_stor_dbg(us, "   ATA OUT - SCSIOP_WRITE\n");
 
 		lba = be32_to_cpu(*(__be32 *)&srb->cmnd[2]);
-		blockCount = (unsigned long)srb->cmnd[7]<<8 | (unsigned long)srb->cmnd[8];
+		blockCount = srb->cmnd[7] << 8 | srb->cmnd[8];
 
 		if (ata_id_has_lba(id)) {
 			sectnum = (unsigned char)(lba);