scsi: aacraid: struct {user,}sgmap{,64,raw}: Replace 1-element arrays with flexible arrays

Replace the deprecated[1] use of 1-element arrays in struct sgmap, struct
sgmap64, struct sgmapraw, struct user_sgmap, and struct user_sgmap64 with
modern flexible arrays. Additionally remove struct user_sgmapraw as it is
unused.

The resulting binary output differences from this change are limited only
to stack space consumption of the smaller "srbu" variable in
aac_issue_safw_bmic_identify() and aac_get_safw_ciss_luns(), as well as the
smaller associated pair of memcpy()s in
aac_send_safw_bmic_cmd(). Artificially growing the size of srbu back to its
prior size removes all binary differences[2].

As an aside, after studying the aacraid driver code I wonder how
aac_send_wellness_command() ever works. It is reporting a size 4 bytes too
small for what it has constructed in memory in the DMA region: sgentry64 is
size 12, whereas sgentry is size 8. Perhaps the hardware doesn't
care. (Regardless, it is unchanged by this patch.)

Link: https://github.com/KSPP/linux/issues/79 [1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?h=dev/v6.10-rc2/1-element&id=45e6226bcbc5e982541754eca7ac29f403e82f5e [2]
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20240711215739.208776-2-kees@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 12 insertions, 14 deletions

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index b22857c6f3f4..6a7159badebb 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -1267,7 +1267,7 @@ static int aac_read_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u3
 			return ret;
 		command = ContainerRawIo;
 		fibsize = sizeof(struct aac_raw_io) +
-			((le32_to_cpu(readcmd->sg.count)-1) * sizeof(struct sgentryraw));
+			(le32_to_cpu(readcmd->sg.count) * sizeof(struct sgentryraw));
 	}
 
 	BUG_ON(fibsize > (fib->dev->max_fib_size - sizeof(struct aac_fibhdr)));
@@ -1302,7 +1302,7 @@ static int aac_read_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u
 	if (ret < 0)
 		return ret;
 	fibsize = sizeof(struct aac_read64) +
-		((le32_to_cpu(readcmd->sg.count) - 1) *
+		(le32_to_cpu(readcmd->sg.count) *
 		 sizeof (struct sgentry64));
 	BUG_ON (fibsize > (fib->dev->max_fib_size -
 				sizeof(struct aac_fibhdr)));
@@ -1337,7 +1337,7 @@ static int aac_read_block(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32
 	if (ret < 0)
 		return ret;
 	fibsize = sizeof(struct aac_read) +
-			((le32_to_cpu(readcmd->sg.count) - 1) *
+			(le32_to_cpu(readcmd->sg.count) *
 			 sizeof (struct sgentry));
 	BUG_ON (fibsize > (fib->dev->max_fib_size -
 				sizeof(struct aac_fibhdr)));
@@ -1401,7 +1401,7 @@ static int aac_write_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u
 			return ret;
 		command = ContainerRawIo;
 		fibsize = sizeof(struct aac_raw_io) +
-			((le32_to_cpu(writecmd->sg.count)-1) * sizeof (struct sgentryraw));
+			(le32_to_cpu(writecmd->sg.count) * sizeof(struct sgentryraw));
 	}
 
 	BUG_ON(fibsize > (fib->dev->max_fib_size - sizeof(struct aac_fibhdr)));
@@ -1436,7 +1436,7 @@ static int aac_write_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba,
 	if (ret < 0)
 		return ret;
 	fibsize = sizeof(struct aac_write64) +
-		((le32_to_cpu(writecmd->sg.count) - 1) *
+		(le32_to_cpu(writecmd->sg.count) *
 		 sizeof (struct sgentry64));
 	BUG_ON (fibsize > (fib->dev->max_fib_size -
 				sizeof(struct aac_fibhdr)));
@@ -1473,7 +1473,7 @@ static int aac_write_block(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u3
 	if (ret < 0)
 		return ret;
 	fibsize = sizeof(struct aac_write) +
-		((le32_to_cpu(writecmd->sg.count) - 1) *
+		(le32_to_cpu(writecmd->sg.count) *
 		 sizeof (struct sgentry));
 	BUG_ON (fibsize > (fib->dev->max_fib_size -
 				sizeof(struct aac_fibhdr)));
@@ -1592,9 +1592,9 @@ static int aac_scsi_64(struct fib * fib, struct scsi_cmnd * cmd)
 	/*
 	 *	Build Scatter/Gather list
 	 */
-	fibsize = sizeof (struct aac_srb) - sizeof (struct sgentry) +
+	fibsize = sizeof(struct aac_srb) +
 		((le32_to_cpu(srbcmd->sg.count) & 0xff) *
-		 sizeof (struct sgentry64));
+		 sizeof(struct sgentry64));
 	BUG_ON (fibsize > (fib->dev->max_fib_size -
 				sizeof(struct aac_fibhdr)));
 
@@ -1624,7 +1624,7 @@ static int aac_scsi_32(struct fib * fib, struct scsi_cmnd * cmd)
 	 *	Build Scatter/Gather list
 	 */
 	fibsize = sizeof (struct aac_srb) +
-		(((le32_to_cpu(srbcmd->sg.count) & 0xff) - 1) *
+		((le32_to_cpu(srbcmd->sg.count) & 0xff) *
 		 sizeof (struct sgentry));
 	BUG_ON (fibsize > (fib->dev->max_fib_size -
 				sizeof(struct aac_fibhdr)));
@@ -1693,8 +1693,7 @@ static int aac_send_safw_bmic_cmd(struct aac_dev *dev,
 	fibptr->hw_fib_va->header.XferState &=
 		~cpu_to_le32(FastResponseCapable);
 
-	fibsize  = sizeof(struct aac_srb) - sizeof(struct sgentry) +
-						sizeof(struct sgentry64);
+	fibsize = sizeof(struct aac_srb) + sizeof(struct sgentry64);
 
 	/* allocate DMA buffer for response */
 	addr = dma_map_single(&dev->pdev->dev, xfer_buf, xfer_len,
@@ -2267,7 +2266,7 @@ int aac_get_adapter_info(struct aac_dev* dev)
 		dev->a_ops.adapter_bounds = aac_bounds_32;
 		dev->scsi_host_ptr->sg_tablesize = (dev->max_fib_size -
 			sizeof(struct aac_fibhdr) -
-			sizeof(struct aac_write) + sizeof(struct sgentry)) /
+			sizeof(struct aac_write)) /
 				sizeof(struct sgentry);
 		if (dev->dac_support) {
 			dev->a_ops.adapter_read = aac_read_block64;
@@ -2278,8 +2277,7 @@ int aac_get_adapter_info(struct aac_dev* dev)
 			dev->scsi_host_ptr->sg_tablesize =
 				(dev->max_fib_size -
 				sizeof(struct aac_fibhdr) -
-				sizeof(struct aac_write64) +
-				sizeof(struct sgentry64)) /
+				sizeof(struct aac_write64)) /
 					sizeof(struct sgentry64);
 		} else {
 			dev->a_ops.adapter_read = aac_read_block;