compat_ioctl: scsi: handle HDIO commands from drivers

The ata_sas_scsi_ioctl() function implements a number of HDIO_* commands
for SCSI devices, it is used by all libata drivers as well as a few
drivers that support SAS attached SATA drives.

The only command that is not safe for compat ioctls here is
HDIO_GET_32BIT. Change the implementation to check for in_compat_syscall()
in order to do both cases correctly, and change all callers to use it
as both native and compat callback pointers, including the indirect
callers through sas_ioctl and ata_scsi_ioctl.

Reviewed-by: Ben Hutchings <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>

drivers/ata/libata-scsi.c

···
  *  - http://www.t13.org/
  */
 
+#include <linux/compat.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/blkdev.h>
···
 	return 0;
 }
 
+/*
+ * This handles both native and compat commands, so anything added
+ * here must have a compatible argument, or check in_compat_syscall()
+ */
 int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
 		     unsigned int cmd, void __user *arg)
 {
···
 		spin_lock_irqsave(ap->lock, flags);
 		val = ata_ioc32(ap);
 		spin_unlock_irqrestore(ap->lock, flags);
+#ifdef CONFIG_COMPAT
+		if (in_compat_syscall())
+			return put_user(val, (compat_ulong_t __user *)arg);
+#endif
 		return put_user(val, (unsigned long __user *)arg);
 
 	case HDIO_SET_32BIT:

drivers/scsi/aic94xx/aic94xx_init.c

···
 	.eh_target_reset_handler	= sas_eh_target_reset_handler,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= sas_ioctl,
+#endif
 	.track_queue_depth	= 1,
 };
 

drivers/scsi/hisi_sas/hisi_sas_v1_hw.c

···
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= sas_ioctl,
+#endif
 	.shost_attrs		= host_attrs_v1_hw,
 	.host_reset             = hisi_sas_host_reset,
 };

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

···
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= sas_ioctl,
+#endif
 	.shost_attrs		= host_attrs_v2_hw,
 	.host_reset		= hisi_sas_host_reset,
 };

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

···
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= sas_ioctl,
+#endif
 	.shost_attrs		= host_attrs_v3_hw,
 	.tag_alloc_policy	= BLK_TAG_ALLOC_RR,
 	.host_reset             = hisi_sas_host_reset,

drivers/scsi/ipr.c

···
 	.name = "IPR",
 	.info = ipr_ioa_info,
 	.ioctl = ipr_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = ipr_ioctl,
+#endif
 	.queuecommand = ipr_queuecommand,
 	.eh_abort_handler = ipr_eh_abort,
 	.eh_device_reset_handler = ipr_eh_dev_reset,

drivers/scsi/isci/init.c

···
 	.eh_target_reset_handler        = sas_eh_target_reset_handler,
 	.target_destroy			= sas_target_destroy,
 	.ioctl				= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl			= sas_ioctl,
+#endif
 	.shost_attrs			= isci_host_attrs,
 	.track_queue_depth		= 1,
 };

drivers/scsi/mvsas/mv_init.c

···
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= sas_ioctl,
+#endif
 	.shost_attrs		= mvst_host_attrs,
 	.track_queue_depth	= 1,
 };

drivers/scsi/pm8001/pm8001_init.c

···
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= sas_ioctl,
+#endif
 	.shost_attrs		= pm8001_host_attrs,
 	.track_queue_depth	= 1,
 };

include/linux/libata.h

···
 extern int ata_scsi_detect(struct scsi_host_template *sht);
 extern int ata_scsi_ioctl(struct scsi_device *dev, unsigned int cmd,
 			  void __user *arg);
+#ifdef CONFIG_COMPAT
+#define ATA_SCSI_COMPAT_IOCTL .compat_ioctl = ata_scsi_ioctl,
+#else
+#define ATA_SCSI_COMPAT_IOCTL /* empty */
+#endif
 extern int ata_scsi_queuecmd(struct Scsi_Host *h, struct scsi_cmnd *cmd);
 extern int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *dev,
 			    unsigned int cmd, void __user *arg);
···
 	.module			= THIS_MODULE,			\
 	.name			= drv_name,			\
 	.ioctl			= ata_scsi_ioctl,		\
+	ATA_SCSI_COMPAT_IOCTL					\
 	.queuecommand		= ata_scsi_queuecmd,		\
 	.can_queue		= ATA_DEF_QUEUE,		\
 	.tag_alloc_policy	= BLK_TAG_ALLOC_RR,		\