diff --git a/Documentation/magic-number.txt b/Documentation/magic-number.txt index 28befed9f610..c74199f60c6c 100644 --- a/Documentation/magic-number.txt +++ b/Documentation/magic-number.txt @@ -1,9 +1,12 @@ +Linux magic numbers +=================== + This file is a registry of magic numbers which are in use. When you add a magic number to a structure, you should also add it to this file, since it is best if the magic numbers used by various structures are unique. -It is a *very* good idea to protect kernel data structures with magic +It is a **very** good idea to protect kernel data structures with magic numbers. This allows you to check at run time whether (a) a structure has been clobbered, or (b) you've passed the wrong structure to a routine. This last is especially useful --- particularly when you are @@ -12,12 +15,12 @@ for example, does this frequently to pass driver-specific and line discipline-specific structures back and forth. The way to use magic numbers is to declare then at the beginning of -the structure, like so: +the structure, like so:: -struct tty_ldisc { - int magic; - ... -}; + struct tty_ldisc { + int magic; + ... + }; Please follow this discipline when you are adding future enhancements to the kernel! It has saved me countless hours of debugging, @@ -25,134 +28,137 @@ especially in the screwy cases where an array has been overrun and structures following the array have been overwritten. Using this discipline, these cases get detected quickly and safely. +Changelog:: + Theodore Ts'o 31 Mar 94 -The magic table is current to Linux 2.1.55. + The magic table is current to Linux 2.1.55. Michael Chastain 22 Sep 1997 -Now it should be up to date with Linux 2.1.112. Because -we are in feature freeze time it is very unlikely that -something will change before 2.2.x. The entries are -sorted by number field. + Now it should be up to date with Linux 2.1.112. Because + we are in feature freeze time it is very unlikely that + something will change before 2.2.x. The entries are + sorted by number field. Krzysztof G. Baranowski 29 Jul 1998 -Updated the magic table to Linux 2.5.45. Right over the feature freeze, -but it is possible that some new magic numbers will sneak into the -kernel before 2.6.x yet. + Updated the magic table to Linux 2.5.45. Right over the feature freeze, + but it is possible that some new magic numbers will sneak into the + kernel before 2.6.x yet. Petr Baudis 03 Nov 2002 -Updated the magic table to Linux 2.5.74. + Updated the magic table to Linux 2.5.74. Fabian Frederick 09 Jul 2003 -Magic Name Number Structure File -=========================================================================== -PG_MAGIC 'P' pg_{read,write}_hdr include/linux/pg.h -CMAGIC 0x0111 user include/linux/a.out.h -MKISS_DRIVER_MAGIC 0x04bf mkiss_channel drivers/net/mkiss.h -HDLC_MAGIC 0x239e n_hdlc drivers/char/n_hdlc.c -APM_BIOS_MAGIC 0x4101 apm_user arch/x86/kernel/apm_32.c -CYCLADES_MAGIC 0x4359 cyclades_port include/linux/cyclades.h -DB_MAGIC 0x4442 fc_info drivers/net/iph5526_novram.c -DL_MAGIC 0x444d fc_info drivers/net/iph5526_novram.c -FASYNC_MAGIC 0x4601 fasync_struct include/linux/fs.h -FF_MAGIC 0x4646 fc_info drivers/net/iph5526_novram.c -ISICOM_MAGIC 0x4d54 isi_port include/linux/isicom.h -PTY_MAGIC 0x5001 drivers/char/pty.c -PPP_MAGIC 0x5002 ppp include/linux/if_pppvar.h -SERIAL_MAGIC 0x5301 async_struct include/linux/serial.h -SSTATE_MAGIC 0x5302 serial_state include/linux/serial.h -SLIP_MAGIC 0x5302 slip drivers/net/slip.h -STRIP_MAGIC 0x5303 strip drivers/net/strip.c -X25_ASY_MAGIC 0x5303 x25_asy drivers/net/x25_asy.h -SIXPACK_MAGIC 0x5304 sixpack drivers/net/hamradio/6pack.h -AX25_MAGIC 0x5316 ax_disp drivers/net/mkiss.h -TTY_MAGIC 0x5401 tty_struct include/linux/tty.h -MGSL_MAGIC 0x5401 mgsl_info drivers/char/synclink.c -TTY_DRIVER_MAGIC 0x5402 tty_driver include/linux/tty_driver.h -MGSLPC_MAGIC 0x5402 mgslpc_info drivers/char/pcmcia/synclink_cs.c -TTY_LDISC_MAGIC 0x5403 tty_ldisc include/linux/tty_ldisc.h -USB_SERIAL_MAGIC 0x6702 usb_serial drivers/usb/serial/usb-serial.h -FULL_DUPLEX_MAGIC 0x6969 drivers/net/ethernet/dec/tulip/de2104x.c -USB_BLUETOOTH_MAGIC 0x6d02 usb_bluetooth drivers/usb/class/bluetty.c -RFCOMM_TTY_MAGIC 0x6d02 net/bluetooth/rfcomm/tty.c -USB_SERIAL_PORT_MAGIC 0x7301 usb_serial_port drivers/usb/serial/usb-serial.h -CG_MAGIC 0x00090255 ufs_cylinder_group include/linux/ufs_fs.h -RPORT_MAGIC 0x00525001 r_port drivers/char/rocket_int.h -LSEMAGIC 0x05091998 lse drivers/fc4/fc.c -GDTIOCTL_MAGIC 0x06030f07 gdth_iowr_str drivers/scsi/gdth_ioctl.h -RIEBL_MAGIC 0x09051990 drivers/net/atarilance.c -NBD_REQUEST_MAGIC 0x12560953 nbd_request include/linux/nbd.h -RED_MAGIC2 0x170fc2a5 (any) mm/slab.c -BAYCOM_MAGIC 0x19730510 baycom_state drivers/net/baycom_epp.c -ISDN_X25IFACE_MAGIC 0x1e75a2b9 isdn_x25iface_proto_data - drivers/isdn/isdn_x25iface.h -ECP_MAGIC 0x21504345 cdkecpsig include/linux/cdk.h -LSOMAGIC 0x27091997 lso drivers/fc4/fc.c -LSMAGIC 0x2a3b4d2a ls drivers/fc4/fc.c -WANPIPE_MAGIC 0x414C4453 sdla_{dump,exec} include/linux/wanpipe.h -CS_CARD_MAGIC 0x43525553 cs_card sound/oss/cs46xx.c -LABELCL_MAGIC 0x4857434c labelcl_info_s include/asm/ia64/sn/labelcl.h -ISDN_ASYNC_MAGIC 0x49344C01 modem_info include/linux/isdn.h -CTC_ASYNC_MAGIC 0x49344C01 ctc_tty_info drivers/s390/net/ctctty.c -ISDN_NET_MAGIC 0x49344C02 isdn_net_local_s drivers/isdn/i4l/isdn_net_lib.h -SAVEKMSG_MAGIC2 0x4B4D5347 savekmsg arch/*/amiga/config.c -CS_STATE_MAGIC 0x4c4f4749 cs_state sound/oss/cs46xx.c -SLAB_C_MAGIC 0x4f17a36d kmem_cache mm/slab.c -COW_MAGIC 0x4f4f4f4d cow_header_v1 arch/um/drivers/ubd_user.c -I810_CARD_MAGIC 0x5072696E i810_card sound/oss/i810_audio.c -TRIDENT_CARD_MAGIC 0x5072696E trident_card sound/oss/trident.c -ROUTER_MAGIC 0x524d4157 wan_device [in wanrouter.h pre 3.9] -SAVEKMSG_MAGIC1 0x53415645 savekmsg arch/*/amiga/config.c -GDA_MAGIC 0x58464552 gda arch/mips/include/asm/sn/gda.h -RED_MAGIC1 0x5a2cf071 (any) mm/slab.c -EEPROM_MAGIC_VALUE 0x5ab478d2 lanai_dev drivers/atm/lanai.c -HDLCDRV_MAGIC 0x5ac6e778 hdlcdrv_state include/linux/hdlcdrv.h -PCXX_MAGIC 0x5c6df104 channel drivers/char/pcxx.h -KV_MAGIC 0x5f4b565f kernel_vars_s arch/mips/include/asm/sn/klkernvars.h -I810_STATE_MAGIC 0x63657373 i810_state sound/oss/i810_audio.c -TRIDENT_STATE_MAGIC 0x63657373 trient_state sound/oss/trident.c -M3_CARD_MAGIC 0x646e6f50 m3_card sound/oss/maestro3.c -FW_HEADER_MAGIC 0x65726F66 fw_header drivers/atm/fore200e.h -SLOT_MAGIC 0x67267321 slot drivers/hotplug/cpqphp.h -SLOT_MAGIC 0x67267322 slot drivers/hotplug/acpiphp.h -LO_MAGIC 0x68797548 nbd_device include/linux/nbd.h -OPROFILE_MAGIC 0x6f70726f super_block drivers/oprofile/oprofilefs.h -M3_STATE_MAGIC 0x734d724d m3_state sound/oss/maestro3.c -VMALLOC_MAGIC 0x87654320 snd_alloc_track sound/core/memory.c -KMALLOC_MAGIC 0x87654321 snd_alloc_track sound/core/memory.c -PWC_MAGIC 0x89DC10AB pwc_device drivers/usb/media/pwc.h -NBD_REPLY_MAGIC 0x96744668 nbd_reply include/linux/nbd.h -ENI155_MAGIC 0xa54b872d midway_eprom drivers/atm/eni.h -CODA_MAGIC 0xC0DAC0DA coda_file_info fs/coda/coda_fs_i.h -DPMEM_MAGIC 0xc0ffee11 gdt_pci_sram drivers/scsi/gdth.h -YAM_MAGIC 0xF10A7654 yam_port drivers/net/hamradio/yam.c -CCB_MAGIC 0xf2691ad2 ccb drivers/scsi/ncr53c8xx.c -QUEUE_MAGIC_FREE 0xf7e1c9a3 queue_entry drivers/scsi/arm/queue.c -QUEUE_MAGIC_USED 0xf7e1cc33 queue_entry drivers/scsi/arm/queue.c -HTB_CMAGIC 0xFEFAFEF1 htb_class net/sched/sch_htb.c -NMI_MAGIC 0x48414d4d455201 nmi_s arch/mips/include/asm/sn/nmi.h +===================== ================ ======================== ========================================== +Magic Name Number Structure File +===================== ================ ======================== ========================================== +PG_MAGIC 'P' pg_{read,write}_hdr ``include/linux/pg.h`` +CMAGIC 0x0111 user ``include/linux/a.out.h`` +MKISS_DRIVER_MAGIC 0x04bf mkiss_channel ``drivers/net/mkiss.h`` +HDLC_MAGIC 0x239e n_hdlc ``drivers/char/n_hdlc.c`` +APM_BIOS_MAGIC 0x4101 apm_user ``arch/x86/kernel/apm_32.c`` +CYCLADES_MAGIC 0x4359 cyclades_port ``include/linux/cyclades.h`` +DB_MAGIC 0x4442 fc_info ``drivers/net/iph5526_novram.c`` +DL_MAGIC 0x444d fc_info ``drivers/net/iph5526_novram.c`` +FASYNC_MAGIC 0x4601 fasync_struct ``include/linux/fs.h`` +FF_MAGIC 0x4646 fc_info ``drivers/net/iph5526_novram.c`` +ISICOM_MAGIC 0x4d54 isi_port ``include/linux/isicom.h`` +PTY_MAGIC 0x5001 ``drivers/char/pty.c`` +PPP_MAGIC 0x5002 ppp ``include/linux/if_pppvar.h`` +SERIAL_MAGIC 0x5301 async_struct ``include/linux/serial.h`` +SSTATE_MAGIC 0x5302 serial_state ``include/linux/serial.h`` +SLIP_MAGIC 0x5302 slip ``drivers/net/slip.h`` +STRIP_MAGIC 0x5303 strip ``drivers/net/strip.c`` +X25_ASY_MAGIC 0x5303 x25_asy ``drivers/net/x25_asy.h`` +SIXPACK_MAGIC 0x5304 sixpack ``drivers/net/hamradio/6pack.h`` +AX25_MAGIC 0x5316 ax_disp ``drivers/net/mkiss.h`` +TTY_MAGIC 0x5401 tty_struct ``include/linux/tty.h`` +MGSL_MAGIC 0x5401 mgsl_info ``drivers/char/synclink.c`` +TTY_DRIVER_MAGIC 0x5402 tty_driver ``include/linux/tty_driver.h`` +MGSLPC_MAGIC 0x5402 mgslpc_info ``drivers/char/pcmcia/synclink_cs.c`` +TTY_LDISC_MAGIC 0x5403 tty_ldisc ``include/linux/tty_ldisc.h`` +USB_SERIAL_MAGIC 0x6702 usb_serial ``drivers/usb/serial/usb-serial.h`` +FULL_DUPLEX_MAGIC 0x6969 ``drivers/net/ethernet/dec/tulip/de2104x.c`` +USB_BLUETOOTH_MAGIC 0x6d02 usb_bluetooth ``drivers/usb/class/bluetty.c`` +RFCOMM_TTY_MAGIC 0x6d02 ``net/bluetooth/rfcomm/tty.c`` +USB_SERIAL_PORT_MAGIC 0x7301 usb_serial_port ``drivers/usb/serial/usb-serial.h`` +CG_MAGIC 0x00090255 ufs_cylinder_group ``include/linux/ufs_fs.h`` +RPORT_MAGIC 0x00525001 r_port ``drivers/char/rocket_int.h`` +LSEMAGIC 0x05091998 lse ``drivers/fc4/fc.c`` +GDTIOCTL_MAGIC 0x06030f07 gdth_iowr_str ``drivers/scsi/gdth_ioctl.h`` +RIEBL_MAGIC 0x09051990 ``drivers/net/atarilance.c`` +NBD_REQUEST_MAGIC 0x12560953 nbd_request ``include/linux/nbd.h`` +RED_MAGIC2 0x170fc2a5 (any) ``mm/slab.c`` +BAYCOM_MAGIC 0x19730510 baycom_state ``drivers/net/baycom_epp.c`` +ISDN_X25IFACE_MAGIC 0x1e75a2b9 isdn_x25iface_proto_data ``drivers/isdn/isdn_x25iface.h`` +ECP_MAGIC 0x21504345 cdkecpsig ``include/linux/cdk.h`` +LSOMAGIC 0x27091997 lso ``drivers/fc4/fc.c`` +LSMAGIC 0x2a3b4d2a ls ``drivers/fc4/fc.c`` +WANPIPE_MAGIC 0x414C4453 sdla_{dump,exec} ``include/linux/wanpipe.h`` +CS_CARD_MAGIC 0x43525553 cs_card ``sound/oss/cs46xx.c`` +LABELCL_MAGIC 0x4857434c labelcl_info_s ``include/asm/ia64/sn/labelcl.h`` +ISDN_ASYNC_MAGIC 0x49344C01 modem_info ``include/linux/isdn.h`` +CTC_ASYNC_MAGIC 0x49344C01 ctc_tty_info ``drivers/s390/net/ctctty.c`` +ISDN_NET_MAGIC 0x49344C02 isdn_net_local_s ``drivers/isdn/i4l/isdn_net_lib.h`` +SAVEKMSG_MAGIC2 0x4B4D5347 savekmsg ``arch/*/amiga/config.c`` +CS_STATE_MAGIC 0x4c4f4749 cs_state ``sound/oss/cs46xx.c`` +SLAB_C_MAGIC 0x4f17a36d kmem_cache ``mm/slab.c`` +COW_MAGIC 0x4f4f4f4d cow_header_v1 ``arch/um/drivers/ubd_user.c`` +I810_CARD_MAGIC 0x5072696E i810_card ``sound/oss/i810_audio.c`` +TRIDENT_CARD_MAGIC 0x5072696E trident_card ``sound/oss/trident.c`` +ROUTER_MAGIC 0x524d4157 wan_device [in ``wanrouter.h`` pre 3.9] +SAVEKMSG_MAGIC1 0x53415645 savekmsg ``arch/*/amiga/config.c`` +GDA_MAGIC 0x58464552 gda ``arch/mips/include/asm/sn/gda.h`` +RED_MAGIC1 0x5a2cf071 (any) ``mm/slab.c`` +EEPROM_MAGIC_VALUE 0x5ab478d2 lanai_dev ``drivers/atm/lanai.c`` +HDLCDRV_MAGIC 0x5ac6e778 hdlcdrv_state ``include/linux/hdlcdrv.h`` +PCXX_MAGIC 0x5c6df104 channel ``drivers/char/pcxx.h`` +KV_MAGIC 0x5f4b565f kernel_vars_s ``arch/mips/include/asm/sn/klkernvars.h`` +I810_STATE_MAGIC 0x63657373 i810_state ``sound/oss/i810_audio.c`` +TRIDENT_STATE_MAGIC 0x63657373 trient_state ``sound/oss/trident.c`` +M3_CARD_MAGIC 0x646e6f50 m3_card ``sound/oss/maestro3.c`` +FW_HEADER_MAGIC 0x65726F66 fw_header ``drivers/atm/fore200e.h`` +SLOT_MAGIC 0x67267321 slot ``drivers/hotplug/cpqphp.h`` +SLOT_MAGIC 0x67267322 slot ``drivers/hotplug/acpiphp.h`` +LO_MAGIC 0x68797548 nbd_device ``include/linux/nbd.h`` +OPROFILE_MAGIC 0x6f70726f super_block ``drivers/oprofile/oprofilefs.h`` +M3_STATE_MAGIC 0x734d724d m3_state ``sound/oss/maestro3.c`` +VMALLOC_MAGIC 0x87654320 snd_alloc_track ``sound/core/memory.c`` +KMALLOC_MAGIC 0x87654321 snd_alloc_track ``sound/core/memory.c`` +PWC_MAGIC 0x89DC10AB pwc_device ``drivers/usb/media/pwc.h`` +NBD_REPLY_MAGIC 0x96744668 nbd_reply ``include/linux/nbd.h`` +ENI155_MAGIC 0xa54b872d midway_eprom ``drivers/atm/eni.h`` +CODA_MAGIC 0xC0DAC0DA coda_file_info ``fs/coda/coda_fs_i.h`` +DPMEM_MAGIC 0xc0ffee11 gdt_pci_sram ``drivers/scsi/gdth.h`` +YAM_MAGIC 0xF10A7654 yam_port ``drivers/net/hamradio/yam.c`` +CCB_MAGIC 0xf2691ad2 ccb ``drivers/scsi/ncr53c8xx.c`` +QUEUE_MAGIC_FREE 0xf7e1c9a3 queue_entry ``drivers/scsi/arm/queue.c`` +QUEUE_MAGIC_USED 0xf7e1cc33 queue_entry ``drivers/scsi/arm/queue.c`` +HTB_CMAGIC 0xFEFAFEF1 htb_class ``net/sched/sch_htb.c`` +NMI_MAGIC 0x48414d4d455201 nmi_s ``arch/mips/include/asm/sn/nmi.h`` +===================== ================ ======================== ========================================== Note that there are also defined special per-driver magic numbers in sound -memory management. See include/sound/sndmagic.h for complete list of them. Many +memory management. See ``include/sound/sndmagic.h`` for complete list of them. Many OSS sound drivers have their magic numbers constructed from the soundcard PCI ID - these are not listed here as well. IrDA subsystem also uses large number of own magic numbers, see -include/net/irda/irda.h for a complete list of them. +``include/net/irda/irda.h`` for a complete list of them. HFS is another larger user of magic numbers - you can find them in -fs/hfs/hfs.h. +``fs/hfs/hfs.h``.