[PATCH 00/24] block, scsi: final compat_ioctl cleanup

[PATCH 00/24] block, scsi: final compat_ioctl cleanup

[Arnd Bergmann]

Hi Jens, James and Martin,

This series concludes the work I did for linux-5.5 on the compat_ioctl()
cleanup, killing off fs/compat_ioctl.c and block/compat_ioctl.c by moving
everything into drivers.

Overall this would be a reduction both in complexity and line count, but
as I'm also adding documentation the overall number of lines increases
in the end.

My plan was originally to keep the SCSI and block parts separate.
This did not work easily because of interdependencies: I cannot
do the final SCSI cleanup in a good way without first addressing the
CDROM ioctls, so this is one series that I hope could be merged through
either the block or the scsi git trees, or possibly both if you can
pull in the same branch.

The series comes in these steps:

1. clean up the sg v3 interface as suggested by Linus. I have
   talked about this with Doug Gilbert as well, and he would
   rebase his sg v4 patches on top of "compat: scsi: sg: fix v3
   compat read/write interface"

2. Four patches for missing block compat_ioctl handlers, to be
   backported into stable kernels. Separate patches because they
   are needed in different stable versions.

3. Actually moving handlers out of block/compat_ioctl.c and
   block/scsi_ioctl.c into drivers, mixed in with cleanup
   patches

4. Document how to do this right. I keep getting asked about this,
   and it helps to point to some documentation file.

The series is avaialable for testing at [1].

       Arnd

[1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=compat-ioctl-endgame

Arnd Bergmann (24):
  compat: ARM64: always include asm-generic/compat.h
  compat: scsi: sg: fix v3 compat read/write interface
  compat_ioctl: block: handle BLKREPORTZONE/BLKRESETZONE
  compat_ioctl: block: handle BLKGETZONESZ/BLKGETNRZONES
  compat_ioctl: block: handle add zone open, close and finish ioctl
  compat_ioctl: block: handle Persistent Reservations
  compaT_ioctl: ubd, aoe: use blkdev_compat_ptr_ioctl
  compat_ioctl: move CDROM_SEND_PACKET handling into scsi
  compat_ioctl: move CDROMREADADIO to cdrom.c
  compat_ioctl: cdrom: handle CDROM_LAST_WRITTEN
  compat_ioctl: block: handle cdrom compat ioctl in non-cdrom drivers
  compat_ioctl: add scsi_compat_ioctl
  compat_ioctl: bsg: add handler
  compat_ioctl: ide: floppy: add handler
  compat_ioctl: scsi: move ioctl handling into drivers
  compat_ioctl: move sys_compat_ioctl() to ioctl.c
  compat_ioctl: simplify the implementation
  compat_ioctl: move cdrom commands into cdrom.c
  compat_ioctl: scsi: handle HDIO commands from drivers
  compat_ioctl: move HDIO ioctl handling into drivers/ide
  compat_ioctl: block: move blkdev_compat_ioctl() into ioctl.c
  compat_ioctl: block: simplify compat_blkpg_ioctl()
  compat_ioctl: simplify up block/ioctl.c
  Documentation: document ioctl interfaces better

 Documentation/core-api/index.rst       |   1 +
 Documentation/core-api/ioctl.rst       | 250 +++++++++++++++
 arch/arm64/include/asm/compat.h        |   5 +-
 arch/um/drivers/ubd_kern.c             |   1 +
 block/Makefile                         |   1 -
 block/bsg.c                            |   1 +
 block/compat_ioctl.c                   | 411 -------------------------
 block/ioctl.c                          | 319 +++++++++++++++----
 block/scsi_ioctl.c                     | 214 ++++++++-----
 drivers/ata/libata-scsi.c              |   9 +
 drivers/block/aoe/aoeblk.c             |   1 +
 drivers/block/floppy.c                 |   3 +
 drivers/block/paride/pcd.c             |   3 +
 drivers/block/paride/pd.c              |   1 +
 drivers/block/paride/pf.c              |   1 +
 drivers/block/pktcdvd.c                |  26 +-
 drivers/block/sunvdc.c                 |   1 +
 drivers/block/virtio_blk.c             |   3 +
 drivers/block/xen-blkfront.c           |   1 +
 drivers/cdrom/cdrom.c                  |  35 ++-
 drivers/cdrom/gdrom.c                  |   3 +
 drivers/ide/ide-cd.c                   |  40 +++
 drivers/ide/ide-disk.c                 |   3 +
 drivers/ide/ide-floppy.c               |   4 +
 drivers/ide/ide-floppy.h               |   2 +
 drivers/ide/ide-floppy_ioctl.c         |  35 +++
 drivers/ide/ide-gd.c                   |  14 +
 drivers/ide/ide-ioctls.c               |  47 ++-
 drivers/ide/ide-tape.c                 |  14 +
 drivers/scsi/aic94xx/aic94xx_init.c    |   3 +
 drivers/scsi/ch.c                      |   9 +-
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c |   3 +
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c |   3 +
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c |   3 +
 drivers/scsi/ipr.c                     |   3 +
 drivers/scsi/isci/init.c               |   3 +
 drivers/scsi/mvsas/mv_init.c           |   3 +
 drivers/scsi/pm8001/pm8001_init.c      |   3 +
 drivers/scsi/scsi_ioctl.c              |  54 +++-
 drivers/scsi/sd.c                      |  50 ++-
 drivers/scsi/sg.c                      | 169 +++++-----
 drivers/scsi/sr.c                      |  53 +++-
 drivers/scsi/st.c                      |  51 +--
 fs/Makefile                            |   2 +-
 fs/compat_ioctl.c                      | 261 ----------------
 fs/internal.h                          |   6 -
 fs/ioctl.c                             | 131 +++++---
 include/linux/blkdev.h                 |   7 +
 include/linux/falloc.h                 |   2 -
 include/linux/fs.h                     |   4 -
 include/linux/ide.h                    |   2 +
 include/linux/libata.h                 |   6 +
 include/scsi/scsi_ioctl.h              |   1 +
 include/scsi/sg.h                      |  30 ++
 54 files changed, 1249 insertions(+), 1062 deletions(-)
 create mode 100644 Documentation/core-api/ioctl.rst
 delete mode 100644 block/compat_ioctl.c
 delete mode 100644 fs/compat_ioctl.c

-- 
2.20.0

Cc: corbet@lwn.net
Cc: catalin.marinas@arm.com
Cc: will@kernel.org
Cc: jdike@addtoit.com
Cc: richard@nod.at
Cc: anton.ivanov@cambridgegreys.com
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: justin@coraid.com
Cc: efremov@linux.com
Cc: tim@cyberelk.net
Cc: mst@redhat.com
Cc: jasowang@redhat.com
Cc: pbonzini@redhat.com
Cc: stefanha@redhat.com
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: sstabellini@kernel.org
Cc: konrad.wilk@oracle.com
Cc: roger.pau@citrix.com
Cc: bp@alien8.de
Cc: davem@davemloft.net
Cc: john.garry@huawei.com
Cc: brking@us.ibm.com
Cc: intel-linux-scu@intel.com
Cc: artur.paszkiewicz@intel.com
Cc: jinpu.wang@cloud.ionos.com
Cc: dgilbert@interlog.com
Cc: Kai.Makisara@kolumbus.fi
Cc: arnd@arndb.de
Cc: damien.lemoal@hgst.com
Cc: hare@suse.com
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-block@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-um@lists.infradead.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-ide@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Cc: linux-fsdevel@vger.kernel.org

[PATCH 14/24] compat_ioctl: ide: floppy: add handler

[Arnd Bergmann]

Rather than relying on fs/compat_ioctl.c, this adds support
for a compat_ioctl() callback in the ide-floppy driver directly,
which lets it translate the scsi commands.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/ide/ide-floppy.c       |  4 ++++
 drivers/ide/ide-floppy.h       |  2 ++
 drivers/ide/ide-floppy_ioctl.c | 36 ++++++++++++++++++++++++++++++++++
 drivers/ide/ide-gd.c           | 14 +++++++++++++
 include/linux/ide.h            |  2 ++
 5 files changed, 58 insertions(+)

diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 1ea2f9e82bf8..1fe1f9d37a51 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -19,6 +19,7 @@
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
+#include <linux/compat.h>
 #include <linux/delay.h>
 #include <linux/timer.h>
 #include <linux/mm.h>
@@ -546,4 +547,7 @@ const struct ide_disk_ops ide_atapi_disk_ops = {
 	.set_doorlock	= ide_set_media_lock,
 	.do_request	= ide_floppy_do_request,
 	.ioctl		= ide_floppy_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ide_floppy_compat_ioctl,
+#endif
 };
diff --git a/drivers/ide/ide-floppy.h b/drivers/ide/ide-floppy.h
index 13c9b4b6d75e..8505a5f58f4e 100644
--- a/drivers/ide/ide-floppy.h
+++ b/drivers/ide/ide-floppy.h
@@ -26,6 +26,8 @@ void ide_floppy_create_read_capacity_cmd(struct ide_atapi_pc *);
 /* ide-floppy_ioctl.c */
 int ide_floppy_ioctl(ide_drive_t *, struct block_device *, fmode_t,
 		     unsigned int, unsigned long);
+int ide_floppy_compat_ioctl(ide_drive_t *, struct block_device *, fmode_t,
+			    unsigned int, unsigned long);
 
 #ifdef CONFIG_IDE_PROC_FS
 /* ide-floppy_proc.c */
diff --git a/drivers/ide/ide-floppy_ioctl.c b/drivers/ide/ide-floppy_ioctl.c
index 40a2ebe34e1d..4fd70f804d6f 100644
--- a/drivers/ide/ide-floppy_ioctl.c
+++ b/drivers/ide/ide-floppy_ioctl.c
@@ -5,6 +5,7 @@
 
 #include <linux/kernel.h>
 #include <linux/ide.h>
+#include <linux/compat.h>
 #include <linux/cdrom.h>
 #include <linux/mutex.h>
 
@@ -302,3 +303,38 @@ int ide_floppy_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	mutex_unlock(&ide_floppy_ioctl_mutex);
 	return err;
 }
+
+#ifdef CONFIG_COMPAT
+int ide_floppy_compat_ioctl(ide_drive_t *drive, struct block_device *bdev,
+			    fmode_t mode, unsigned int cmd, unsigned long arg)
+{
+	struct ide_atapi_pc pc;
+	void __user *argp = compat_ptr(arg);
+	int err;
+
+	mutex_lock(&ide_floppy_ioctl_mutex);
+	if (cmd == CDROMEJECT || cmd == CDROM_LOCKDOOR) {
+		err = ide_floppy_lockdoor(drive, &pc, arg, cmd);
+		goto out;
+	}
+
+	err = ide_floppy_format_ioctl(drive, &pc, mode, cmd, argp);
+	if (err != -ENOTTY)
+		goto out;
+
+	/*
+	 * skip SCSI_IOCTL_SEND_COMMAND (deprecated)
+	 * and CDROM_SEND_PACKET (legacy) ioctls
+	 */
+	if (cmd != CDROM_SEND_PACKET && cmd != SCSI_IOCTL_SEND_COMMAND)
+		err = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
+
+	/*
+	 * there is no generic_ide_compat_ioctl(), that is handled
+	 * through compat_blkdev_ioctl().
+	 */
+out:
+	mutex_unlock(&ide_floppy_ioctl_mutex);
+	return err;
+}
+#endif
diff --git a/drivers/ide/ide-gd.c b/drivers/ide/ide-gd.c
index dba9ad5c97b3..1b0270efcce2 100644
--- a/drivers/ide/ide-gd.c
+++ b/drivers/ide/ide-gd.c
@@ -341,11 +341,25 @@ static int ide_gd_ioctl(struct block_device *bdev, fmode_t mode,
 	return drive->disk_ops->ioctl(drive, bdev, mode, cmd, arg);
 }
 
+#ifdef CONFIG_COMPAT
+static int ide_gd_compat_ioctl(struct block_device *bdev, fmode_t mode,
+			       unsigned int cmd, unsigned long arg)
+{
+	struct ide_disk_obj *idkp = ide_drv_g(bdev->bd_disk, ide_disk_obj);
+	ide_drive_t *drive = idkp->drive;
+
+	return drive->disk_ops->compat_ioctl(drive, bdev, mode, cmd, arg);
+}
+#endif
+
 static const struct block_device_operations ide_gd_ops = {
 	.owner			= THIS_MODULE,
 	.open			= ide_gd_unlocked_open,
 	.release		= ide_gd_release,
 	.ioctl			= ide_gd_ioctl,
+#ifdef CONFIG_COMPAT
+	.ioctl			= ide_gd_compat_ioctl,
+#endif
 	.getgeo			= ide_gd_getgeo,
 	.check_events		= ide_gd_check_events,
 	.unlock_native_capacity	= ide_gd_unlock_native_capacity,
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 46b771d6999e..06dae6438557 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -413,6 +413,8 @@ struct ide_disk_ops {
 				      sector_t);
 	int		(*ioctl)(struct ide_drive_s *, struct block_device *,
 				 fmode_t, unsigned int, unsigned long);
+	int		(*compat_ioctl)(struct ide_drive_s *, struct block_device *,
+					fmode_t, unsigned int, unsigned long);
 };
 
 /* ATAPI device flags */
-- 
2.20.0

[PATCH 18/24] compat_ioctl: move cdrom commands into cdrom.c

[Arnd Bergmann]

There is no need for the special cases for the cdrom ioctls any more now,
so make sure that each cdrom driver has a .compat_ioctl() callback and
calls cdrom_compat_ioctl() directly there.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 block/compat_ioctl.c       | 45 --------------------------------------
 drivers/block/paride/pcd.c |  3 +++
 drivers/cdrom/gdrom.c      |  3 +++
 drivers/ide/ide-cd.c       | 36 ++++++++++++++++++++++++++++++
 drivers/scsi/sr.c          | 10 +++------
 5 files changed, 45 insertions(+), 52 deletions(-)

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index cf136bc2c9fc..7cb534d6e767 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -159,42 +159,6 @@ static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 	case HDIO_DRIVE_CMD:
 	/* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
 	case 0x330:
-	/* CDROM stuff */
-	case CDROMPAUSE:
-	case CDROMRESUME:
-	case CDROMPLAYMSF:
-	case CDROMPLAYTRKIND:
-	case CDROMREADTOCHDR:
-	case CDROMREADTOCENTRY:
-	case CDROMSTOP:
-	case CDROMSTART:
-	case CDROMEJECT:
-	case CDROMVOLCTRL:
-	case CDROMSUBCHNL:
-	case CDROMMULTISESSION:
-	case CDROM_GET_MCN:
-	case CDROMRESET:
-	case CDROMVOLREAD:
-	case CDROMSEEK:
-	case CDROMPLAYBLK:
-	case CDROMCLOSETRAY:
-	case CDROM_DISC_STATUS:
-	case CDROM_CHANGER_NSLOTS:
-	case CDROM_GET_CAPABILITY:
-	case CDROM_SEND_PACKET:
-	/* Ignore cdrom.h about these next 5 ioctls, they absolutely do
-	 * not take a struct cdrom_read, instead they take a struct cdrom_msf
-	 * which is compatible.
-	 */
-	case CDROMREADMODE2:
-	case CDROMREADMODE1:
-	case CDROMREADRAW:
-	case CDROMREADCOOKED:
-	case CDROMREADALL:
-	/* DVD ioctls */
-	case DVD_READ_STRUCT:
-	case DVD_WRITE_STRUCT:
-	case DVD_AUTH:
 		arg = (unsigned long)compat_ptr(arg);
 	/* These intepret arg as an unsigned long, not as a pointer,
 	 * so we must not do compat_ptr() conversion. */
@@ -210,15 +174,6 @@ static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 	case HDIO_SET_ACOUSTIC:
 	case HDIO_SET_BUSSTATE:
 	case HDIO_SET_ADDRESS:
-	case CDROMEJECT_SW:
-	case CDROM_SET_OPTIONS:
-	case CDROM_CLEAR_OPTIONS:
-	case CDROM_SELECT_SPEED:
-	case CDROM_SELECT_DISC:
-	case CDROM_MEDIA_CHANGED:
-	case CDROM_DRIVE_STATUS:
-	case CDROM_LOCKDOOR:
-	case CDROM_DEBUG:
 		break;
 	default:
 		/* unknown ioctl number */
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 636bfea2de6f..117cfc8cd05a 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -275,6 +275,9 @@ static const struct block_device_operations pcd_bdops = {
 	.open		= pcd_block_open,
 	.release	= pcd_block_release,
 	.ioctl		= pcd_block_ioctl,
+#ifdef CONFIG_COMPAT
+	.ioctl		= blkdev_compat_ptr_ioctl,
+#endif
 	.check_events	= pcd_block_check_events,
 };
 
diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
index 5b21dc421c94..886b2638c730 100644
--- a/drivers/cdrom/gdrom.c
+++ b/drivers/cdrom/gdrom.c
@@ -518,6 +518,9 @@ static const struct block_device_operations gdrom_bdops = {
 	.release		= gdrom_bdops_release,
 	.check_events		= gdrom_bdops_check_events,
 	.ioctl			= gdrom_bdops_ioctl,
+#ifdef CONFIG_COMPAT
+	.ioctl			= blkdev_compat_ptr_ioctl,
+#endif
 };
 
 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 9d117936bee1..2de6e8ace957 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -25,6 +25,7 @@
 
 #define IDECD_VERSION "5.00"
 
+#include <linux/compat.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -1710,6 +1711,38 @@ static int idecd_ioctl(struct block_device *bdev, fmode_t mode,
 	return ret;
 }
 
+#ifdef CONFIG_COMPAT
+static int idecd_locked_compat_ioctl(struct block_device *bdev, fmode_t mode,
+			unsigned int cmd, unsigned long arg)
+{
+	struct cdrom_info *info = ide_drv_g(bdev->bd_disk, cdrom_info);
+	int err;
+
+	switch (cmd) {
+	case CDROMSETSPINDOWN:
+		return idecd_set_spindown(&info->devinfo, arg);
+	case CDROMGETSPINDOWN:
+		return idecd_get_spindown(&info->devinfo, arg);
+	default:
+		break;
+	}
+
+	return cdrom_ioctl(&info->devinfo, bdev, mode, cmd,
+			   (unsigned long)compat_ptr(arg));
+}
+
+static int idecd_compat_ioctl(struct block_device *bdev, fmode_t mode,
+			     unsigned int cmd, unsigned long arg)
+{
+	int ret;
+
+	mutex_lock(&ide_cd_mutex);
+	ret = idecd_locked_compat_ioctl(bdev, mode, cmd, arg);
+	mutex_unlock(&ide_cd_mutex);
+
+	return ret;
+}
+#endif
 
 static unsigned int idecd_check_events(struct gendisk *disk,
 				       unsigned int clearing)
@@ -1732,6 +1765,9 @@ static const struct block_device_operations idecd_ops = {
 	.open			= idecd_open,
 	.release		= idecd_release,
 	.ioctl			= idecd_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= idecd_compat_ioctl,
+#endif
 	.check_events		= idecd_check_events,
 	.revalidate_disk	= idecd_revalidate_disk
 };
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 6033a886c42c..0fbb8fe6e521 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -628,13 +628,9 @@ static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsign
 		goto put;
 	}
 
-	/*
-	 * CDROM ioctls are handled in the block layer, but
-	 * do the scsi blk ioctls here.
-	 */
-	ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
-	if (ret != -ENOTTY)
-		return ret;
+	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp);
+	if (ret != -ENOSYS)
+		goto put;
 
 	ret = scsi_compat_ioctl(sdev, cmd, argp);
 
-- 
2.20.0

[PATCH 19/24] compat_ioctl: scsi: handle HDIO commands from drivers

[Arnd Bergmann]

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.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/ata/libata-scsi.c              | 9 +++++++++
 drivers/scsi/aic94xx/aic94xx_init.c    | 3 +++
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c | 3 +++
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 3 +++
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 +++
 drivers/scsi/ipr.c                     | 3 +++
 drivers/scsi/isci/init.c               | 3 +++
 drivers/scsi/mvsas/mv_init.c           | 3 +++
 drivers/scsi/pm8001/pm8001_init.c      | 3 +++
 include/linux/libata.h                 | 6 ++++++
 10 files changed, 39 insertions(+)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 58e09ffe8b9c..eb2eb599e602 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -17,6 +17,7 @@
  *  - http://www.t13.org/
  */
 
+#include <linux/compat.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/blkdev.h>
@@ -761,6 +762,10 @@ static int ata_ioc32(struct ata_port *ap)
 	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)
 {
@@ -773,6 +778,10 @@ int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
 		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:
diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c
index f5781e31f57c..d022407e5645 100644
--- a/drivers/scsi/aic94xx/aic94xx_init.c
+++ b/drivers/scsi/aic94xx/aic94xx_init.c
@@ -54,6 +54,9 @@ static struct scsi_host_template aic94xx_sht = {
 	.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,
 };
 
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
index 3af53cc42bd6..fa25766502a2 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
@@ -1772,6 +1772,9 @@ static struct scsi_host_template sht_v1_hw = {
 	.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,
 };
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index 61b1e2693b08..545eaff5f3ee 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -3551,6 +3551,9 @@ static struct scsi_host_template sht_v2_hw = {
 	.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,
 };
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index bf5d5f138437..fa05e612d85a 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -3075,6 +3075,9 @@ static struct scsi_host_template sht_v3_hw = {
 	.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,
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 079c04bc448a..ae45cbe98ae2 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -6727,6 +6727,9 @@ static struct scsi_host_template driver_template = {
 	.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,
diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
index 1727d0c71b12..b48aac8dfcb8 100644
--- a/drivers/scsi/isci/init.c
+++ b/drivers/scsi/isci/init.c
@@ -168,6 +168,9 @@ static struct scsi_host_template isci_sht = {
 	.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,
 };
diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index da719b0694dc..7af9173c4925 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -47,6 +47,9 @@ static struct scsi_host_template mvs_sht = {
 	.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,
 };
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index ff618ad80ebd..3c6076e4c6d2 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -101,6 +101,9 @@ static struct scsi_host_template pm8001_sht = {
 	.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,
 };
diff --git a/include/linux/libata.h b/include/linux/libata.h
index d3bbfddf616a..e68d05febe5a 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1109,6 +1109,11 @@ extern void ata_host_init(struct ata_host *, struct device *, struct ata_port_op
 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);
@@ -1340,6 +1345,7 @@ extern struct device_attribute *ata_common_sdev_attrs[];
 	.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,		\
-- 
2.20.0

[PATCH 20/24] compat_ioctl: move HDIO ioctl handling into drivers/ide

[Arnd Bergmann]

Most of the HDIO ioctls are only used by the obsolete drivers/ide
subsystem, these can be handled by changing ide_cmd_ioctl() to be aware
of compat mode and doing the correct transformations in place and using
it as both native and compat handlers for all drivers.

The SCSI drivers implementing the same commands are already doing
this in the drivers, so the compat_blkdev_driver_ioctl() function
is no longer needed now.

The BLKSECTSET and HDIO_GETGEO_BIG ioctls are not implemented
in any driver any more and no longer need any conversion.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 block/compat_ioctl.c           | 75 ----------------------------------
 drivers/ide/ide-cd.c           |  8 +++-
 drivers/ide/ide-disk.c         |  3 ++
 drivers/ide/ide-floppy_ioctl.c |  7 ++--
 drivers/ide/ide-ioctls.c       | 47 +++++++++++++--------
 drivers/ide/ide-tape.c         | 14 +++++++
 6 files changed, 57 insertions(+), 97 deletions(-)

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 7cb534d6e767..765aa5357655 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -77,24 +77,6 @@ static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
 	return ret;
 }
 
-static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode,
-		unsigned int cmd, unsigned long arg)
-{
-	unsigned long __user *p;
-	int error;
-
-	p = compat_alloc_user_space(sizeof(unsigned long));
-	error = __blkdev_driver_ioctl(bdev, mode,
-				cmd, (unsigned long)p);
-	if (error == 0) {
-		unsigned int __user *uvp = compat_ptr(arg);
-		unsigned long v;
-		if (get_user(v, p) || put_user(v, uvp))
-			error = -EFAULT;
-	}
-	return error;
-}
-
 struct compat_blkpg_ioctl_arg {
 	compat_int_t op;
 	compat_int_t flags;
@@ -128,61 +110,6 @@ static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
 #define BLKBSZSET_32		_IOW(0x12, 113, int)
 #define BLKGETSIZE64_32		_IOR(0x12, 114, int)
 
-static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
-			unsigned cmd, unsigned long arg)
-{
-	switch (cmd) {
-	case HDIO_GET_UNMASKINTR:
-	case HDIO_GET_MULTCOUNT:
-	case HDIO_GET_KEEPSETTINGS:
-	case HDIO_GET_32BIT:
-	case HDIO_GET_NOWERR:
-	case HDIO_GET_DMA:
-	case HDIO_GET_NICE:
-	case HDIO_GET_WCACHE:
-	case HDIO_GET_ACOUSTIC:
-	case HDIO_GET_ADDRESS:
-	case HDIO_GET_BUSSTATE:
-		return compat_hdio_ioctl(bdev, mode, cmd, arg);
-
-	/*
-	 * No handler required for the ones below, we just need to
-	 * convert arg to a 64 bit pointer.
-	 */
-	case BLKSECTSET:
-	/*
-	 * 0x03 -- HD/IDE ioctl's used by hdparm and friends.
-	 *         Some need translations, these do not.
-	 */
-	case HDIO_GET_IDENTITY:
-	case HDIO_DRIVE_TASK:
-	case HDIO_DRIVE_CMD:
-	/* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
-	case 0x330:
-		arg = (unsigned long)compat_ptr(arg);
-	/* These intepret arg as an unsigned long, not as a pointer,
-	 * so we must not do compat_ptr() conversion. */
-	case HDIO_SET_MULTCOUNT:
-	case HDIO_SET_UNMASKINTR:
-	case HDIO_SET_KEEPSETTINGS:
-	case HDIO_SET_32BIT:
-	case HDIO_SET_NOWERR:
-	case HDIO_SET_DMA:
-	case HDIO_SET_PIO_MODE:
-	case HDIO_SET_NICE:
-	case HDIO_SET_WCACHE:
-	case HDIO_SET_ACOUSTIC:
-	case HDIO_SET_BUSSTATE:
-	case HDIO_SET_ADDRESS:
-		break;
-	default:
-		/* unknown ioctl number */
-		return -ENOIOCTLCMD;
-	}
-
-	return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
-}
-
 /* Most of the generic ioctls are handled in the normal fallback path.
    This assumes the blkdev's low level compat_ioctl always returns
    ENOIOCTLCMD for unknown ioctls. */
@@ -293,8 +220,6 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 	default:
 		if (disk->fops->compat_ioctl)
 			ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
-		if (ret == -ENOIOCTLCMD)
-			ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg);
 		return ret;
 	}
 }
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 2de6e8ace957..521564da8707 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1727,8 +1727,12 @@ static int idecd_locked_compat_ioctl(struct block_device *bdev, fmode_t mode,
 		break;
 	}
 
-	return cdrom_ioctl(&info->devinfo, bdev, mode, cmd,
-			   (unsigned long)compat_ptr(arg));
+	err = generic_ide_ioctl(info->drive, bdev, cmd, arg);
+	if (err == -EINVAL)
+		err = cdrom_ioctl(&info->devinfo, bdev, mode, cmd,
+				  (unsigned long)compat_ptr(arg));
+
+	return err;
 }
 
 static int idecd_compat_ioctl(struct block_device *bdev, fmode_t mode,
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 197912af5c2f..27f1098e4bcd 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -794,4 +794,7 @@ const struct ide_disk_ops ide_ata_disk_ops = {
 	.set_doorlock		= ide_disk_set_doorlock,
 	.do_request		= ide_do_rw_disk,
 	.ioctl			= ide_disk_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= ide_disk_ioctl,
+#endif
 };
diff --git a/drivers/ide/ide-floppy_ioctl.c b/drivers/ide/ide-floppy_ioctl.c
index 4fd70f804d6f..39a790ac6cc3 100644
--- a/drivers/ide/ide-floppy_ioctl.c
+++ b/drivers/ide/ide-floppy_ioctl.c
@@ -329,10 +329,9 @@ int ide_floppy_compat_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	if (cmd != CDROM_SEND_PACKET && cmd != SCSI_IOCTL_SEND_COMMAND)
 		err = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
 
-	/*
-	 * there is no generic_ide_compat_ioctl(), that is handled
-	 * through compat_blkdev_ioctl().
-	 */
+	if (err == -ENOTTY)
+		err = generic_ide_ioctl(drive, bdev, cmd, arg);
+
 out:
 	mutex_unlock(&ide_floppy_ioctl_mutex);
 	return err;
diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index d48c17003874..d97da46fdd79 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -3,11 +3,21 @@
  * IDE ioctls handling.
  */
 
+#include <linux/compat.h>
 #include <linux/export.h>
 #include <linux/hdreg.h>
 #include <linux/ide.h>
 #include <linux/slab.h>
 
+static int put_user_long(long val, unsigned long arg)
+{
+#ifdef CONFIG_COMPAT
+	if (in_compat_syscall())
+		return put_user(val, (compat_long_t __user *)compat_ptr(arg));
+#endif
+	return put_user(val, (long __user *)arg);
+}
+
 static const struct ide_ioctl_devset ide_ioctl_settings[] = {
 { HDIO_GET_32BIT,	 HDIO_SET_32BIT,	&ide_devset_io_32bit  },
 { HDIO_GET_KEEPSETTINGS, HDIO_SET_KEEPSETTINGS,	&ide_devset_keepsettings },
@@ -37,7 +47,7 @@ int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	mutex_lock(&ide_setting_mtx);
 	err = ds->get(drive);
 	mutex_unlock(&ide_setting_mtx);
-	return err >= 0 ? put_user(err, (long __user *)arg) : err;
+	return err >= 0 ? put_user_long(err, arg) : err;
 
 set_val:
 	if (bdev != bdev->bd_contains)
@@ -56,7 +66,7 @@ int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev,
 EXPORT_SYMBOL_GPL(ide_setting_ioctl);
 
 static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd,
-				  unsigned long arg)
+				  void __user *argp)
 {
 	u16 *id = NULL;
 	int size = (cmd == HDIO_GET_IDENTITY) ? (ATA_ID_WORDS * 2) : 142;
@@ -77,7 +87,7 @@ static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd,
 	memcpy(id, drive->id, size);
 	ata_id_to_hd_driveid(id);
 
-	if (copy_to_user((void __user *)arg, id, size))
+	if (copy_to_user(argp, id, size))
 		rc = -EFAULT;
 
 	kfree(id);
@@ -87,10 +97,10 @@ static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd,
 
 static int ide_get_nice_ioctl(ide_drive_t *drive, unsigned long arg)
 {
-	return put_user((!!(drive->dev_flags & IDE_DFLAG_DSC_OVERLAP)
+	return put_user_long((!!(drive->dev_flags & IDE_DFLAG_DSC_OVERLAP)
 			 << IDE_NICE_DSC_OVERLAP) |
 			(!!(drive->dev_flags & IDE_DFLAG_NICE1)
-			 << IDE_NICE_1), (long __user *)arg);
+			 << IDE_NICE_1), arg);
 }
 
 static int ide_set_nice_ioctl(ide_drive_t *drive, unsigned long arg)
@@ -115,7 +125,7 @@ static int ide_set_nice_ioctl(ide_drive_t *drive, unsigned long arg)
 	return 0;
 }
 
-static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
+static int ide_cmd_ioctl(ide_drive_t *drive, void __user *argp)
 {
 	u8 *buf = NULL;
 	int bufsize = 0, err = 0;
@@ -123,7 +133,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 	struct ide_cmd cmd;
 	struct ide_taskfile *tf = &cmd.tf;
 
-	if (NULL == (void *) arg) {
+	if (NULL == argp) {
 		struct request *rq;
 
 		rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
@@ -135,7 +145,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 		return err;
 	}
 
-	if (copy_from_user(args, (void __user *)arg, 4))
+	if (copy_from_user(args, argp, 4))
 		return -EFAULT;
 
 	memset(&cmd, 0, sizeof(cmd));
@@ -181,19 +191,18 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 	args[1] = tf->error;
 	args[2] = tf->nsect;
 abort:
-	if (copy_to_user((void __user *)arg, &args, 4))
+	if (copy_to_user(argp, &args, 4))
 		err = -EFAULT;
 	if (buf) {
-		if (copy_to_user((void __user *)(arg + 4), buf, bufsize))
+		if (copy_to_user((argp + 4), buf, bufsize))
 			err = -EFAULT;
 		kfree(buf);
 	}
 	return err;
 }
 
-static int ide_task_ioctl(ide_drive_t *drive, unsigned long arg)
+static int ide_task_ioctl(ide_drive_t *drive, void __user *p)
 {
-	void __user *p = (void __user *)arg;
 	int err = 0;
 	u8 args[7];
 	struct ide_cmd cmd;
@@ -237,6 +246,12 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev,
 		      unsigned int cmd, unsigned long arg)
 {
 	int err;
+	void __user *argp = (void __user *)arg;
+
+#ifdef CONFIG_COMPAT
+	if (in_compat_syscall())
+		argp = compat_ptr(arg);
+#endif
 
 	err = ide_setting_ioctl(drive, bdev, cmd, arg, ide_ioctl_settings);
 	if (err != -EOPNOTSUPP)
@@ -247,7 +262,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	case HDIO_GET_IDENTITY:
 		if (bdev != bdev->bd_contains)
 			return -EINVAL;
-		return ide_get_identity_ioctl(drive, cmd, arg);
+		return ide_get_identity_ioctl(drive, cmd, argp);
 	case HDIO_GET_NICE:
 		return ide_get_nice_ioctl(drive, arg);
 	case HDIO_SET_NICE:
@@ -265,11 +280,11 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	case HDIO_DRIVE_CMD:
 		if (!capable(CAP_SYS_RAWIO))
 			return -EACCES;
-		return ide_cmd_ioctl(drive, arg);
+		return ide_cmd_ioctl(drive, argp);
 	case HDIO_DRIVE_TASK:
 		if (!capable(CAP_SYS_RAWIO))
 			return -EACCES;
-		return ide_task_ioctl(drive, arg);
+		return ide_task_ioctl(drive, argp);
 	case HDIO_DRIVE_RESET:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EACCES;
@@ -277,7 +292,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	case HDIO_GET_BUSSTATE:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EACCES;
-		if (put_user(BUSSTATE_ON, (long __user *)arg))
+		if (put_user_long(BUSSTATE_ON, arg))
 			return -EFAULT;
 		return 0;
 	case HDIO_SET_BUSSTATE:
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 3e7482695f77..4c2a95a2f0b6 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -1945,11 +1945,25 @@ static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
 	return err;
 }
 
+#ifdef CONFIG_COMPAT
+static int idetape_compat_ioctl(struct block_device *bdev, fmode_t mode,
+				unsigned int cmd, unsigned long arg)
+{
+        if (cmd == 0x0340 || cmd == 0x350)
+		arg = (unsigned long)compat_ptr(arg);
+
+	return idetape_ioctl(bdev, mode, cmd, arg);
+}
+#endif
+
 static const struct block_device_operations idetape_block_ops = {
 	.owner		= THIS_MODULE,
 	.open		= idetape_open,
 	.release	= idetape_release,
 	.ioctl		= idetape_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= idetape_compat_ioctl,
+#endif
 };
 
 static int ide_tape_probe(ide_drive_t *drive)
-- 
2.20.0

Re: [PATCH 20/24] compat_ioctl: move HDIO ioctl handling into drivers/ide

[Christoph Hellwig]

> +static int put_user_long(long val, unsigned long arg)
> +{
> +#ifdef CONFIG_COMPAT
> +	if (in_compat_syscall())
> +		return put_user(val, (compat_long_t __user *)compat_ptr(arg));
> +#endif
> +	return put_user(val, (long __user *)arg);
> +}

We had this

#ifdef CONFIG_COMPAT
	if (in_compat_syscall())
		...
	...
#endif

patter quite frequently.  Can we define a in_compat_syscall stub
and make sure compat_ptr and the compat_* types are available available
to clean this up a bit?

> -	if (NULL == (void *) arg) {
> +	if (NULL == argp) {

	if (!argp) {

?

Re: [PATCH 20/24] compat_ioctl: move HDIO ioctl handling into drivers/ide

[Arnd Bergmann]

On Thu, Dec 12, 2019 at 5:29 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> > +static int put_user_long(long val, unsigned long arg)
> > +{
> > +#ifdef CONFIG_COMPAT
> > +     if (in_compat_syscall())
> > +             return put_user(val, (compat_long_t __user *)compat_ptr(arg));
> > +#endif
> > +     return put_user(val, (long __user *)arg);
> > +}
>
> We had this
>
> #ifdef CONFIG_COMPAT
>         if (in_compat_syscall())
>                 ...
>         ...
> #endif
>
> patter quite frequently.  Can we define a in_compat_syscall stub
> and make sure compat_ptr and the compat_* types are available available
> to clean this up a bit?

in_compat_syscall() already has a reasonable stub, what was missing
when I created this series is the compat_long_t definition and
the compat_ptr() helper.

With patch 01/24, we can rely on the types, but I still need to add
a generic compat_ptr() implementation for non-s390 to remove the
#ifdef here.

That is probably a good idea anyway, it just needs a bit of testing.
The last time I tried this, I ran into problems with the order of compat
header inclusions on some architectures.

I've made a prototype now, will see how it goes.

> > -     if (NULL == (void *) arg) {
> > +     if (NULL == argp) {
>
>         if (!argp) {
>
> ?

changed now.

      Arnd