This file is a registry of magic numbers which are in use.  When youadd a magic number to a structure, you should also add it to thisfile, since it is best if the magic numbers used by various structuresare unique.It is a *very* good idea to protect kernel data structures with magicnumbers.  This allows you to check at run time whether (a) a structurehas been clobbered, or (b) you've passed the wrong structure to aroutine.  This last is especially useful --- particularly when you arepassing pointers to structures via a void * pointer.  The tty code,for example, does this frequently to pass driver-specific and linediscipline-specific structures back and forth.The way to use magic numbers is to declare then at the beginning ofthe structure, like so:struct tty_ldisc {	int	magic;	...};Please follow this discipline when you are adding future enhancementsto the kernel!  It has saved me countless hours of debugging,especially in the screwy cases where an array has been overrun andstructures following the array have been overwritten.  Using thisdiscipline, these cases get detected quickly and safely.					Theodore Ts'o					31 Mar 94The magic table is current to Linux 2.1.55.					Michael Chastain					<mailto:mec@shout.net>					22 Sep 1997Now it should be up to date with Linux 2.1.112. Becausewe are in feature freeze time it is very unlikely thatsomething will change before 2.2.x. The entries aresorted by number field.					Krzysztof G. Baranowski					<mailto: kgb@knm.org.pl>					29 Jul 1998Magic Name            Number      Structure            File===========================================================================PG_MAGIC	      'P'	  pg_{read,write}_hdr include/linux/pg.hMKISS_DRIVER_MAGIC    0x04bf      mkiss_channel     drivers/net/mkiss.hRISCOM8_MAGIC         0x0907      riscom_port       drivers/char/riscom8.hAPM_BIOS_MAGIC        0x4101      apm_user          arch/i386/kernel/apm.cCYCLADES_MAGIC        0x4359      cyclades_port     include/linux/cyclades.hFASYNC_MAGIC          0x4601      fasync_struct     include/linux/fs.hPTY_MAGIC	      0x5001	  (none at the moment)					            drivers/char/pty.cPPP_MAGIC             0x5002      ppp               include/linux/if_ppp.hSERIAL_MAGIC          0x5301      async_struct      include/linux/serial.hSSTATE_MAGIC          0x5302      serial_state      include/linux/serial.hSLIP_MAGIC            0x5302      slip              drivers/net/slip.hSTRIP_MAGIC           0x5303      strip             drivers/net/strip.cX25_ASY_MAGIC         0x5303      x25_asy           drivers/net/x25_asy.hSIXPACK_MAGIC	      0x5304      sixpack	    drivers/net/hamradio/6pack.hAX25_MAGIC            0x5316      ax_disp           drivers/net/mkiss.hESP_MAGIC             0x53ee      esp_struct        drivers/char/esp.hTTY_MAGIC             0x5401      tty_struct        include/linux/tty.hTTY_DRIVER_MAGIC      0x5402      tty_driver        include/linux/tty_driver.hTTY_LDISC_MAGIC       0x5403      tty_ldisc         include/linux/tty_ldisc.hSPECIALIX_MAGIC       0x0907      specialix_port    drivers/char/specialix_io8.hCG_MAGIC	      0x090255    ufs_cylinder_group include/linux/ufs_fs.hRPORT_MAGIC           0x525001    r_port            drivers/char/rocket_int.hGDTIOCTL_MAGIC	      0x06030f07  gdth_iowr_str     drivers/scsi/gdth_ioctl.hNBD_REQUEST_MAGIC     0x12560953  nbd_request       include/linux/nbd.hSLAB_RED_MAGIC2       0x170fc2a5  (any)             mm/slab.cBAYCOM_MAGIC          0x19730510  baycom_state      drivers/net/baycom_epp.cISDN_X25IFACE_MAGIC   0x1e75a2b9  isdn_x25iface_proto_data                                                    drivers/isdn/isdn_x25iface.hECP_MAGIC             0x21504345  cdkecpsig         include/linux/cdk.hLSMAGIC               0x2a3b4d2a  ls                drivers/fc4/fc.cLSOMAGIC              0x2a3c4e3c  lso               drivers/fc4/fc.cWANPIPE_MAGIC         0x414C4453  sdla_{dump,exec}  include/linux/wanpipe.hCODA_CNODE_MAGIC      0x47114711  coda_inode_info   include/linux/coda_fs_i.hISDN_ASYNC_MAGIC      0x49344C01  modem_info        include/linux/isdn.hISDN_NET_MAGIC        0x49344C02  isdn_net_local_s  include/linux/isdn.hSTLI_BOARDMAGIC       0x4bc6c825  stlibrd           include/linux/istallion.hSLAB_C_MAGIC          0x4f17a36d  kmem_cache_s      mm/slab.cROUTER_MAGIC          0x524d4157  wan_device        include/linux/wanrouter.hSLAB_RED_MAGIC1       0x5a2cf071  (any)             mm/slab.cSTL_PORTMAGIC         0x5a7182c9  stlport           include/linux/stallion.hHDLCDRV_MAGIC         0x5ac6e778  hdlcdrv_state     include/linux/hdlcdrv.hEPCA_MAGIC     	      0x5c6df104  channel           include/linux/epca.hPCXX_MAGIC            0x5c6df104  channel           drivers/char/pcxx.hLO_MAGIC              0x68797548  nbd_device        include/linux/nbd.hSTL_PANELMAGIC        0x7ef621a1  stlpanel          include/linux/stallion.hNBD_REPLY_MAGIC       0x96744668  nbd_reply         include/linux/nbd.hSTL_BOARDMAGIC        0xa2267f52  stlbrd            include/linux/stallion.hSLAB_MAGIC_ALLOC      0xa5c32f2b  kmem_slab_s       mm/slab.cSLAB_MAGIC_DESTROYED  0xb2f23c5a  kmem_slab_s       mm/slab.cSTLI_PORTMAGIC        0xe671c7a1  stliport          include/linux/istallion.hCCB_MAGIC             0xf2691ad2  ccb               drivers/scsi/ncr53c8xx.c