^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. _magicnumbers:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Linux magic numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) ===================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) This file is a registry of magic numbers which are in use. When you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) add a magic number to a structure, you should also add it to this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) file, since it is best if the magic numbers used by various structures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) are unique.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) It is a **very** good idea to protect kernel data structures with magic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) numbers. This allows you to check at run time whether (a) a structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) has been clobbered, or (b) you've passed the wrong structure to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) routine. This last is especially useful --- particularly when you are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) passing pointers to structures via a void * pointer. The tty code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) for example, does this frequently to pass driver-specific and line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) discipline-specific structures back and forth.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) The way to use magic numbers is to declare them at the beginning of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) the structure, like so::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) struct tty_ldisc {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) int magic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) Please follow this discipline when you are adding future enhancements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) to the kernel! It has saved me countless hours of debugging,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) especially in the screwy cases where an array has been overrun and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) structures following the array have been overwritten. Using this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) discipline, these cases get detected quickly and safely.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) Changelog::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) Theodore Ts'o
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 31 Mar 94
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) The magic table is current to Linux 2.1.55.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) Michael Chastain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) <mailto:mec@shout.net>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 22 Sep 1997
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) Now it should be up to date with Linux 2.1.112. Because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) we are in feature freeze time it is very unlikely that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) something will change before 2.2.x. The entries are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) sorted by number field.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) Krzysztof G. Baranowski
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) <mailto: kgb@knm.org.pl>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 29 Jul 1998
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) Updated the magic table to Linux 2.5.45. Right over the feature freeze,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) but it is possible that some new magic numbers will sneak into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) kernel before 2.6.x yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) Petr Baudis
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) <pasky@ucw.cz>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 03 Nov 2002
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) Updated the magic table to Linux 2.5.74.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) Fabian Frederick
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) <ffrederick@users.sourceforge.net>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 09 Jul 2003
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) ===================== ================ ======================== ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) Magic Name Number Structure File
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) ===================== ================ ======================== ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) PG_MAGIC 'P' pg_{read,write}_hdr ``include/linux/pg.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) CMAGIC 0x0111 user ``include/linux/a.out.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) MKISS_DRIVER_MAGIC 0x04bf mkiss_channel ``drivers/net/mkiss.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) HDLC_MAGIC 0x239e n_hdlc ``drivers/char/n_hdlc.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) APM_BIOS_MAGIC 0x4101 apm_user ``arch/x86/kernel/apm_32.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) CYCLADES_MAGIC 0x4359 cyclades_port ``include/linux/cyclades.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) DB_MAGIC 0x4442 fc_info ``drivers/net/iph5526_novram.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) DL_MAGIC 0x444d fc_info ``drivers/net/iph5526_novram.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) FASYNC_MAGIC 0x4601 fasync_struct ``include/linux/fs.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) FF_MAGIC 0x4646 fc_info ``drivers/net/iph5526_novram.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) ISICOM_MAGIC 0x4d54 isi_port ``include/linux/isicom.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) PTY_MAGIC 0x5001 ``drivers/char/pty.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) PPP_MAGIC 0x5002 ppp ``include/linux/if_pppvar.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) SSTATE_MAGIC 0x5302 serial_state ``include/linux/serial.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) SLIP_MAGIC 0x5302 slip ``drivers/net/slip.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) STRIP_MAGIC 0x5303 strip ``drivers/net/strip.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) X25_ASY_MAGIC 0x5303 x25_asy ``drivers/net/x25_asy.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) SIXPACK_MAGIC 0x5304 sixpack ``drivers/net/hamradio/6pack.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) AX25_MAGIC 0x5316 ax_disp ``drivers/net/mkiss.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) TTY_MAGIC 0x5401 tty_struct ``include/linux/tty.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) MGSL_MAGIC 0x5401 mgsl_info ``drivers/char/synclink.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) TTY_DRIVER_MAGIC 0x5402 tty_driver ``include/linux/tty_driver.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) MGSLPC_MAGIC 0x5402 mgslpc_info ``drivers/char/pcmcia/synclink_cs.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) TTY_LDISC_MAGIC 0x5403 tty_ldisc ``include/linux/tty_ldisc.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) USB_SERIAL_MAGIC 0x6702 usb_serial ``drivers/usb/serial/usb-serial.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) FULL_DUPLEX_MAGIC 0x6969 ``drivers/net/ethernet/dec/tulip/de2104x.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) USB_BLUETOOTH_MAGIC 0x6d02 usb_bluetooth ``drivers/usb/class/bluetty.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) RFCOMM_TTY_MAGIC 0x6d02 ``net/bluetooth/rfcomm/tty.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) USB_SERIAL_PORT_MAGIC 0x7301 usb_serial_port ``drivers/usb/serial/usb-serial.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) CG_MAGIC 0x00090255 ufs_cylinder_group ``include/linux/ufs_fs.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) RPORT_MAGIC 0x00525001 r_port ``drivers/char/rocket_int.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) LSEMAGIC 0x05091998 lse ``drivers/fc4/fc.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) GDTIOCTL_MAGIC 0x06030f07 gdth_iowr_str ``drivers/scsi/gdth_ioctl.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) RIEBL_MAGIC 0x09051990 ``drivers/net/atarilance.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) NBD_REQUEST_MAGIC 0x12560953 nbd_request ``include/linux/nbd.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) RED_MAGIC2 0x170fc2a5 (any) ``mm/slab.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) BAYCOM_MAGIC 0x19730510 baycom_state ``drivers/net/baycom_epp.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) ISDN_X25IFACE_MAGIC 0x1e75a2b9 isdn_x25iface_proto_data ``drivers/isdn/isdn_x25iface.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) ECP_MAGIC 0x21504345 cdkecpsig ``include/linux/cdk.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) LSOMAGIC 0x27091997 lso ``drivers/fc4/fc.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) LSMAGIC 0x2a3b4d2a ls ``drivers/fc4/fc.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) WANPIPE_MAGIC 0x414C4453 sdla_{dump,exec} ``include/linux/wanpipe.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) CS_CARD_MAGIC 0x43525553 cs_card ``sound/oss/cs46xx.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) LABELCL_MAGIC 0x4857434c labelcl_info_s ``include/asm/ia64/sn/labelcl.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) ISDN_ASYNC_MAGIC 0x49344C01 modem_info ``include/linux/isdn.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) CTC_ASYNC_MAGIC 0x49344C01 ctc_tty_info ``drivers/s390/net/ctctty.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) ISDN_NET_MAGIC 0x49344C02 isdn_net_local_s ``drivers/isdn/i4l/isdn_net_lib.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) SAVEKMSG_MAGIC2 0x4B4D5347 savekmsg ``arch/*/amiga/config.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) CS_STATE_MAGIC 0x4c4f4749 cs_state ``sound/oss/cs46xx.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) SLAB_C_MAGIC 0x4f17a36d kmem_cache ``mm/slab.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) COW_MAGIC 0x4f4f4f4d cow_header_v1 ``arch/um/drivers/ubd_user.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) I810_CARD_MAGIC 0x5072696E i810_card ``sound/oss/i810_audio.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) TRIDENT_CARD_MAGIC 0x5072696E trident_card ``sound/oss/trident.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) ROUTER_MAGIC 0x524d4157 wan_device [in ``wanrouter.h`` pre 3.9]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) SAVEKMSG_MAGIC1 0x53415645 savekmsg ``arch/*/amiga/config.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) GDA_MAGIC 0x58464552 gda ``arch/mips/include/asm/sn/gda.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) RED_MAGIC1 0x5a2cf071 (any) ``mm/slab.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) EEPROM_MAGIC_VALUE 0x5ab478d2 lanai_dev ``drivers/atm/lanai.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) HDLCDRV_MAGIC 0x5ac6e778 hdlcdrv_state ``include/linux/hdlcdrv.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) PCXX_MAGIC 0x5c6df104 channel ``drivers/char/pcxx.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) KV_MAGIC 0x5f4b565f kernel_vars_s ``arch/mips/include/asm/sn/klkernvars.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) I810_STATE_MAGIC 0x63657373 i810_state ``sound/oss/i810_audio.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) TRIDENT_STATE_MAGIC 0x63657373 trient_state ``sound/oss/trident.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) M3_CARD_MAGIC 0x646e6f50 m3_card ``sound/oss/maestro3.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) FW_HEADER_MAGIC 0x65726F66 fw_header ``drivers/atm/fore200e.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) SLOT_MAGIC 0x67267321 slot ``drivers/hotplug/cpqphp.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) SLOT_MAGIC 0x67267322 slot ``drivers/hotplug/acpiphp.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) LO_MAGIC 0x68797548 nbd_device ``include/linux/nbd.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) OPROFILE_MAGIC 0x6f70726f super_block ``drivers/oprofile/oprofilefs.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) M3_STATE_MAGIC 0x734d724d m3_state ``sound/oss/maestro3.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) VMALLOC_MAGIC 0x87654320 snd_alloc_track ``sound/core/memory.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) KMALLOC_MAGIC 0x87654321 snd_alloc_track ``sound/core/memory.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) PWC_MAGIC 0x89DC10AB pwc_device ``drivers/usb/media/pwc.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) NBD_REPLY_MAGIC 0x96744668 nbd_reply ``include/linux/nbd.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) ENI155_MAGIC 0xa54b872d midway_eprom ``drivers/atm/eni.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) CODA_MAGIC 0xC0DAC0DA coda_file_info ``fs/coda/coda_fs_i.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) DPMEM_MAGIC 0xc0ffee11 gdt_pci_sram ``drivers/scsi/gdth.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) YAM_MAGIC 0xF10A7654 yam_port ``drivers/net/hamradio/yam.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) CCB_MAGIC 0xf2691ad2 ccb ``drivers/scsi/ncr53c8xx.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) QUEUE_MAGIC_FREE 0xf7e1c9a3 queue_entry ``drivers/scsi/arm/queue.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) QUEUE_MAGIC_USED 0xf7e1cc33 queue_entry ``drivers/scsi/arm/queue.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) HTB_CMAGIC 0xFEFAFEF1 htb_class ``net/sched/sch_htb.c``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) NMI_MAGIC 0x48414d4d455201 nmi_s ``arch/mips/include/asm/sn/nmi.h``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) ===================== ================ ======================== ==========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) Note that there are also defined special per-driver magic numbers in sound
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) memory management. See ``include/sound/sndmagic.h`` for complete list of them. Many
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) OSS sound drivers have their magic numbers constructed from the soundcard PCI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) ID - these are not listed here as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) HFS is another larger user of magic numbers - you can find them in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) ``fs/hfs/hfs.h``.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags