On Wed, 2019-12-18 at 23:17 +0100, Arnd Bergmann wrote: > On Wed, Dec 18, 2019 at 10:11 PM Ben Hutchings > <ben.hutchings@xxxxxxxxxxxxxxx> wrote: > > On Tue, 2019-12-17 at 23:17 +0100, Arnd Bergmann wrote: > > > 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. > > [...] > > > > I noticed that HDIO_DRIVE_TASKFILE, handled by ide_taskfile_ioctl() in > > drivers/ide/ide-taskfile.c, never had compat handling before. After > > this patch it does, but its argument isn't passed through compat_ptr(). > > Again, doesn't really matter because IDE isn't a thing on s390. > > I checked again, and I think it's worse than that: ide_taskfile_ioctl() > takes an ide_task_request_t argument, which is not compatible > at all (it has two long members). I suspect what happened here > is that I confused it with ide_cmd_ioctl(), which takes a 'struct > ide_taskfile' argument that /is/ compatible. > > I don't think there is a point in adding a handler now: most > users of drivers/ide are 32-bit only, and nobody complained > so far, but I would add this change if you agree: Looks good to me. Ben. > diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c > index f6497c817493..83afee3983fe 100644 > --- a/drivers/ide/ide-ioctls.c > +++ b/drivers/ide/ide-ioctls.c > @@ -270,6 +270,9 @@ int generic_ide_ioctl(ide_drive_t *drive, struct > block_device *bdev, > case HDIO_DRIVE_TASKFILE: > if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) > return -EACCES; > + /* missing compat handler for HDIO_DRIVE_TASKFILE */ > + if (in_compat_syscall()) > + return -ENOTTY; > if (drive->media == ide_disk) > return ide_taskfile_ioctl(drive, arg); > return -ENOMSG; > > > > Arnd > -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom
