| Ioctl Numbers |
| 19 October 1999 |
| Michael Elizabeth Chastain |
| <mec@shout.net> |
| |
| If you are adding new ioctl's to the kernel, you should use the _IO |
| macros defined in <linux/ioctl.h>: |
| |
| _IO an ioctl with no parameters |
| _IOW an ioctl with write parameters (copy_from_user) |
| _IOR an ioctl with read parameters (copy_to_user) |
| _IOWR an ioctl with both write and read parameters. |
| |
| 'Write' and 'read' are from the user's point of view, just like the |
| system calls 'write' and 'read'. For example, a SET_FOO ioctl would |
| be _IOW, although the kernel would actually read data from user space; |
| a GET_FOO ioctl would be _IOR, although the kernel would actually write |
| data to user space. |
| |
| The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter |
| or number from the table below. Because of the large number of drivers, |
| many drivers share a partial letter with other drivers. |
| |
| If you are writing a driver for a new device and need a letter, pick an |
| unused block with enough room for expansion: 32 to 256 ioctl commands. |
| You can register the block by patching this file and submitting the |
| patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and |
| I'll register one for you. |
| |
| The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number |
| to distinguish ioctls from each other. The third argument to _IOW, |
| _IOR, or _IOWR is the type of the data going into the kernel or coming |
| out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use |
| sizeof(arg) as the third argument as this results in your ioctl thinking |
| it passes an argument of type size_t. |
| |
| Some devices use their major number as the identifier; this is OK, as |
| long as it is unique. Some devices are irregular and don't follow any |
| convention at all. |
| |
| Following this convention is good because: |
| |
| (1) Keeping the ioctl's globally unique helps error checking: |
| if a program calls an ioctl on the wrong device, it will get an |
| error rather than some unexpected behaviour. |
| |
| (2) The 'strace' build procedure automatically finds ioctl numbers |
| defined with _IO, _IOW, _IOR, or _IOWR. |
| |
| (3) 'strace' can decode numbers back into useful names when the |
| numbers are unique. |
| |
| (4) People looking for ioctls can grep for them more easily when |
| this convention is used to define the ioctl numbers. |
| |
| (5) When following the convention, the driver code can use generic |
| code to copy the parameters between user and kernel space. |
| |
| This table lists ioctls visible from user land for Linux/x86. It contains |
| most drivers up to 2.6.31, but I know I am missing some. There has been |
| no attempt to list non-X86 architectures or ioctls from drivers/staging/. |
| |
| Code Seq#(hex) Include File Comments |
| ======================================================== |
| 0x00 00-1F linux/fs.h conflict! |
| 0x00 00-1F scsi/scsi_ioctl.h conflict! |
| 0x00 00-1F linux/fb.h conflict! |
| 0x00 00-1F linux/wavefront.h conflict! |
| 0x02 all linux/fd.h |
| 0x03 all linux/hdreg.h |
| 0x04 D2-DC linux/umsdos_fs.h Dead since 2.6.11, but don't reuse these. |
| 0x06 all linux/lp.h |
| 0x09 all linux/raid/md_u.h |
| 0x10 00-0F drivers/char/s390/vmcp.h |
| 0x10 10-1F arch/s390/include/uapi/sclp_ctl.h |
| 0x10 20-2F arch/s390/include/uapi/asm/hypfs.h |
| 0x12 all linux/fs.h |
| linux/blkpg.h |
| 0x1b all InfiniBand Subsystem <http://infiniband.sourceforge.net/> |
| 0x20 all drivers/cdrom/cm206.h |
| 0x22 all scsi/sg.h |
| '#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem |
| '$' 00-0F linux/perf_counter.h, linux/perf_event.h |
| '%' 00-0F include/uapi/linux/stm.h |
| System Trace Module subsystem |
| <mailto:alexander.shishkin@linux.intel.com> |
| '&' 00-07 drivers/firewire/nosy-user.h |
| '1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl |
| <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> |
| '2' 01-04 linux/i2o.h |
| '3' 00-0F drivers/s390/char/raw3270.h conflict! |
| '3' 00-1F linux/suspend_ioctls.h conflict! |
| and kernel/power/user.c |
| '8' all SNP8023 advanced NIC card |
| <mailto:mcr@solidum.com> |
| ';' 64-7F linux/vfio.h |
| '@' 00-0F linux/radeonfb.h conflict! |
| '@' 00-0F drivers/video/aty/aty128fb.c conflict! |
| 'A' 00-1F linux/apm_bios.h conflict! |
| 'A' 00-0F linux/agpgart.h conflict! |
| and drivers/char/agp/compat_ioctl.h |
| 'A' 00-7F sound/asound.h conflict! |
| 'B' 00-1F linux/cciss_ioctl.h conflict! |
| 'B' 00-0F include/linux/pmu.h conflict! |
| 'B' C0-FF advanced bbus |
| <mailto:maassen@uni-freiburg.de> |
| 'C' all linux/soundcard.h conflict! |
| 'C' 01-2F linux/capi.h conflict! |
| 'C' F0-FF drivers/net/wan/cosa.h conflict! |
| 'D' all arch/s390/include/asm/dasd.h |
| 'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h |
| 'D' 05 drivers/scsi/pmcraid.h |
| 'E' all linux/input.h conflict! |
| 'E' 00-0F xen/evtchn.h conflict! |
| 'F' all linux/fb.h conflict! |
| 'F' 01-02 drivers/scsi/pmcraid.h conflict! |
| 'F' 20 drivers/video/fsl-diu-fb.h conflict! |
| 'F' 20 drivers/video/intelfb/intelfb.h conflict! |
| 'F' 20 linux/ivtvfb.h conflict! |
| 'F' 20 linux/matroxfb.h conflict! |
| 'F' 20 drivers/video/aty/atyfb_base.c conflict! |
| 'F' 00-0F video/da8xx-fb.h conflict! |
| 'F' 80-8F linux/arcfb.h conflict! |
| 'F' DD video/sstfb.h conflict! |
| 'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! |
| 'G' 00-0F linux/gigaset_dev.h conflict! |
| 'H' 00-7F linux/hiddev.h conflict! |
| 'H' 00-0F linux/hidraw.h conflict! |
| 'H' 01 linux/mei.h conflict! |
| 'H' 02 linux/mei.h conflict! |
| 'H' 03 linux/mei.h conflict! |
| 'H' 00-0F sound/asound.h conflict! |
| 'H' 20-40 sound/asound_fm.h conflict! |
| 'H' 80-8F sound/sfnt_info.h conflict! |
| 'H' 10-8F sound/emu10k1.h conflict! |
| 'H' 10-1F sound/sb16_csp.h conflict! |
| 'H' 10-1F sound/hda_hwdep.h conflict! |
| 'H' 40-4F sound/hdspm.h conflict! |
| 'H' 40-4F sound/hdsp.h conflict! |
| 'H' 90 sound/usb/usx2y/usb_stream.h |
| 'H' A0 uapi/linux/usb/cdc-wdm.h |
| 'H' C0-F0 net/bluetooth/hci.h conflict! |
| 'H' C0-DF net/bluetooth/hidp/hidp.h conflict! |
| 'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict! |
| 'H' C0-DF net/bluetooth/bnep/bnep.h conflict! |
| 'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net> |
| 'H' F8-FA sound/firewire.h |
| 'I' all linux/isdn.h conflict! |
| 'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict! |
| 'I' 40-4F linux/mISDNif.h conflict! |
| 'J' 00-1F drivers/scsi/gdth_ioctl.h |
| 'K' all linux/kd.h |
| 'L' 00-1F linux/loop.h conflict! |
| 'L' 10-1F drivers/scsi/mpt2sas/mpt2sas_ctl.h conflict! |
| 'L' 20-2F linux/lightnvm.h |
| 'L' E0-FF linux/ppdd.h encrypted disk device driver |
| <http://linux01.gwdg.de/~alatham/ppdd.html> |
| 'M' all linux/soundcard.h conflict! |
| 'M' 01-16 mtd/mtd-abi.h conflict! |
| and drivers/mtd/mtdchar.c |
| 'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h |
| 'M' 00-0F drivers/video/fsl-diu-fb.h conflict! |
| 'N' 00-1F drivers/usb/scanner.h |
| 'N' 40-7F drivers/block/nvme.c |
| 'O' 00-06 mtd/ubi-user.h UBI |
| 'P' all linux/soundcard.h conflict! |
| 'P' 60-6F sound/sscape_ioctl.h conflict! |
| 'P' 00-0F drivers/usb/class/usblp.c conflict! |
| 'Q' all linux/soundcard.h |
| 'R' 00-1F linux/random.h conflict! |
| 'R' 01 linux/rfkill.h conflict! |
| 'R' C0-DF net/bluetooth/rfcomm.h |
| 'S' all linux/cdrom.h conflict! |
| 'S' 80-81 scsi/scsi_ioctl.h conflict! |
| 'S' 82-FF scsi/scsi.h conflict! |
| 'S' 00-7F sound/asequencer.h conflict! |
| 'T' all linux/soundcard.h conflict! |
| 'T' 00-AF sound/asound.h conflict! |
| 'T' all arch/x86/include/asm/ioctls.h conflict! |
| 'T' C0-DF linux/if_tun.h conflict! |
| 'U' all sound/asound.h conflict! |
| 'U' 00-CF linux/uinput.h conflict! |
| 'U' 00-EF linux/usbdevice_fs.h |
| 'U' C0-CF drivers/bluetooth/hci_uart.h |
| 'V' all linux/vt.h conflict! |
| 'V' all linux/videodev2.h conflict! |
| 'V' C0 linux/ivtvfb.h conflict! |
| 'V' C0 linux/ivtv.h conflict! |
| 'V' C0 media/davinci/vpfe_capture.h conflict! |
| 'V' C0 media/si4713.h conflict! |
| 'W' 00-1F linux/watchdog.h conflict! |
| 'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) |
| 'W' 00-3F sound/asound.h conflict! |
| 'W' 40-5F drivers/pci/switch/switchtec.c |
| 'X' all fs/xfs/xfs_fs.h conflict! |
| and fs/xfs/linux-2.6/xfs_ioctl32.h |
| and include/linux/falloc.h |
| and linux/fs.h |
| 'X' all fs/ocfs2/ocfs_fs.h conflict! |
| 'X' 01 linux/pktcdvd.h conflict! |
| 'Y' all linux/cyclades.h |
| 'Z' 14-15 drivers/message/fusion/mptctl.h |
| '[' 00-07 linux/usb/tmc.h USB Test and Measurement Devices |
| <mailto:gregkh@linuxfoundation.org> |
| 'a' all linux/atm*.h, linux/sonet.h ATM on linux |
| <http://lrcwww.epfl.ch/> |
| 'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver |
| 'b' 00-FF conflict! bit3 vme host bridge |
| <mailto:natalia@nikhefk.nikhef.nl> |
| 'c' all linux/cm4000_cs.h conflict! |
| 'c' 00-7F linux/comstats.h conflict! |
| 'c' 00-7F linux/coda.h conflict! |
| 'c' 00-1F linux/chio.h conflict! |
| 'c' 80-9F arch/s390/include/asm/chsc.h conflict! |
| 'c' A0-AF arch/x86/include/asm/msr.h conflict! |
| 'd' 00-FF linux/char/drm/drm.h conflict! |
| 'd' 02-40 pcmcia/ds.h conflict! |
| 'd' F0-FF linux/digi1.h |
| 'e' all linux/digi1.h conflict! |
| 'f' 00-1F linux/ext2_fs.h conflict! |
| 'f' 00-1F linux/ext3_fs.h conflict! |
| 'f' 00-0F fs/jfs/jfs_dinode.h conflict! |
| 'f' 00-0F fs/ext4/ext4.h conflict! |
| 'f' 00-0F linux/fs.h conflict! |
| 'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! |
| 'g' 00-0F linux/usb/gadgetfs.h |
| 'g' 20-2F linux/usb/g_printer.h |
| 'h' 00-7F conflict! Charon filesystem |
| <mailto:zapman@interlan.net> |
| 'h' 00-1F linux/hpet.h conflict! |
| 'h' 80-8F fs/hfsplus/ioctl.c |
| 'i' 00-3F linux/i2o-dev.h conflict! |
| 'i' 0B-1F linux/ipmi.h conflict! |
| 'i' 80-8F linux/i8k.h |
| 'j' 00-3F linux/joystick.h |
| 'k' 00-0F linux/spi/spidev.h conflict! |
| 'k' 00-05 video/kyro.h conflict! |
| 'k' 10-17 linux/hsi/hsi_char.h HSI character device |
| 'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system |
| <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs> |
| 'l' 40-7F linux/udf_fs_i.h in development: |
| <http://sourceforge.net/projects/linux-udf/> |
| 'm' 00-09 linux/mmtimer.h conflict! |
| 'm' all linux/mtio.h conflict! |
| 'm' all linux/soundcard.h conflict! |
| 'm' all linux/synclink.h conflict! |
| 'm' 00-19 drivers/message/fusion/mptctl.h conflict! |
| 'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! |
| 'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c |
| 'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 |
| 'n' E0-FF linux/matroxfb.h matroxfb |
| 'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 |
| 'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) |
| 'o' 40-41 mtd/ubi-user.h UBI |
| 'o' 01-A1 linux/dvb/*.h DVB |
| 'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) |
| 'p' 00-1F linux/rtc.h conflict! |
| 'p' 00-3F linux/mc146818rtc.h conflict! |
| 'p' 40-7F linux/nvram.h |
| 'p' 80-9F linux/ppdev.h user-space parport |
| <mailto:tim@cyberelk.net> |
| 'p' A1-A5 linux/pps.h LinuxPPS |
| <mailto:giometti@linux.it> |
| 'q' 00-1F linux/serio.h |
| 'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK |
| linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net> |
| 'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c |
| 's' all linux/cdk.h |
| 't' 00-7F linux/ppp-ioctl.h |
| 't' 80-8F linux/isdn_ppp.h |
| 't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM |
| 'u' 00-1F linux/smb_fs.h gone |
| 'u' 20-3F linux/uvcvideo.h USB video class host driver |
| 'v' 00-1F linux/ext2_fs.h conflict! |
| 'v' 00-1F linux/fs.h conflict! |
| 'v' 00-0F linux/sonypi.h conflict! |
| 'v' C0-FF linux/meye.h conflict! |
| 'w' all CERN SCI driver |
| 'y' 00-1F packet based user level communications |
| <mailto:zapman@interlan.net> |
| 'z' 00-3F CAN bus card conflict! |
| <mailto:hdstich@connectu.ulm.circular.de> |
| 'z' 40-7F CAN bus card conflict! |
| <mailto:oe@port.de> |
| 'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! |
| '|' 00-7F linux/media.h |
| 0x80 00-1F linux/fb.h |
| 0x89 00-06 arch/x86/include/asm/sockios.h |
| 0x89 0B-DF linux/sockios.h |
| 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range |
| 0x89 E0-EF linux/dn.h PROTOPRIVATE range |
| 0x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range |
| 0x8B all linux/wireless.h |
| 0x8C 00-3F WiNRADiO driver |
| <http://www.winradio.com.au/> |
| 0x90 00 drivers/cdrom/sbpcd.h |
| 0x92 00-0F drivers/usb/mon/mon_bin.c |
| 0x93 60-7F linux/auto_fs.h |
| 0x94 all fs/btrfs/ioctl.h Btrfs filesystem |
| and linux/fs.h some lifted to vfs/generic |
| 0x97 00-7F fs/ceph/ioctl.h Ceph file system |
| 0x99 00-0F 537-Addinboard driver |
| <mailto:buk@buks.ipn.de> |
| 0xA0 all linux/sdp/sdp.h Industrial Device Project |
| <mailto:kenji@bitgate.com> |
| 0xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver |
| 0xA3 80-8F Port ACL in development: |
| <mailto:tlewis@mindspring.com> |
| 0xA3 90-9F linux/dtlk.h |
| 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem |
| 0xAA 00-3F linux/uapi/linux/userfaultfd.h |
| 0xAB 00-1F linux/nbd.h |
| 0xAC 00-1F linux/raw.h |
| 0xAD 00 Netfilter device in development: |
| <mailto:rusty@rustcorp.com.au> |
| 0xAE all linux/kvm.h Kernel-based Virtual Machine |
| <mailto:kvm@vger.kernel.org> |
| 0xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor |
| 0xB0 all RATIO devices in development: |
| <mailto:vgo@ratio.de> |
| 0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca> |
| 0xB3 00 linux/mmc/ioctl.h |
| 0xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> |
| 0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> |
| 0xC0 00-0F linux/usb/iowarrior.h |
| 0xCA 00-0F uapi/misc/cxl.h |
| 0xCA 10-2F uapi/misc/ocxl.h |
| 0xCA 80-BF uapi/scsi/cxlflash_ioctl.h |
| 0xCB 00-1F CBM serial IEC bus in development: |
| <mailto:michael.klein@puffin.lb.shuttle.de> |
| 0xCD 01 linux/reiserfs_fs.h |
| 0xCF 02 fs/cifs/ioctl.c |
| 0xDB 00-0F drivers/char/mwave/mwavepub.h |
| 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/ |
| <mailto:aherrman@de.ibm.com> |
| 0xE5 00-3F linux/fuse.h |
| 0xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver |
| 0xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) |
| <mailto:thomas@winischhofer.net> |
| 0xF4 00-1F video/mbxfb.h mbxfb |
| <mailto:raph@8d.com> |
| 0xF6 all LTTng Linux Trace Toolkit Next Generation |
| <mailto:mathieu.desnoyers@efficios.com> |
| 0xFD all linux/dm-ioctl.h |
