libata: sanitize ata_tf_read_block()

Return U64_MAX if ata_tf_read_block() could not decode the LBA
address, and do not set the information sense descriptor in
ata_gen_ata_sense() in these cases.

tj: s/(u64)-1/U64_MAX/
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/libata-core.c

@@ -695,7 +695,7 @@ static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
  *	RETURNS:
  *	Block address read from @tf.
  */
-u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
+u64 ata_tf_read_block(const struct ata_taskfile *tf, struct ata_device *dev)
 {
 	u64 block = 0;
 
@@ -720,7 +720,7 @@ u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
 		if (!sect) {
 			ata_dev_warn(dev,
 				     "device reported invalid CHS sector 0\n");
-			sect = 1; /* oh well */
+			return U64_MAX;
 		}
 
 		block = (cyl * dev->heads + head) * dev->sectors + sect - 1;

drivers/ata/libata-scsi.c

@@ -1083,6 +1083,8 @@ static void ata_gen_ata_sense(struct ata_queued_cmd *qc)
 	}
 
 	block = ata_tf_read_block(&qc->result_tf, dev);
+	if (block == U64_MAX)
+		return;
 
 	/* information sense data descriptor */
 	sb[7] = 12;

drivers/ata/libata.h

@@ -67,7 +67,8 @@ extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag);
 extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 			   u64 block, u32 n_block, unsigned int tf_flags,
 			   unsigned int tag);
-extern u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev);
+extern u64 ata_tf_read_block(const struct ata_taskfile *tf,
+			     struct ata_device *dev);
 extern unsigned ata_exec_internal(struct ata_device *dev,
 				  struct ata_taskfile *tf, const u8 *cdb,
 				  int dma_dir, void *buf, unsigned int buflen,