| 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 |
| 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 |
| passing pointers to structures via a void * pointer. The tty code, |
| 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: |
| |
| 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, |
| 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. |
| |
| Theodore Ts'o |
| 31 Mar 94 |
| |
| The magic table is current to Linux 2.1.55. |
| |
| Michael Chastain |
| <mailto:mec@shout.net> |
| 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. |
| |
| Krzysztof G. Baranowski |
| <mailto: kgb@knm.org.pl> |
| 29 Jul 1998 |
| |
| Magic Name Number Structure File |
| =========================================================================== |
| PG_MAGIC 'P' pg_{read,write}_hdr include/linux/pg.h |
| MKISS_DRIVER_MAGIC 0x04bf mkiss_channel drivers/net/mkiss.h |
| RISCOM8_MAGIC 0x0907 riscom_port drivers/char/riscom8.h |
| APM_BIOS_MAGIC 0x4101 apm_user arch/i386/kernel/apm.c |
| CYCLADES_MAGIC 0x4359 cyclades_port include/linux/cyclades.h |
| FASYNC_MAGIC 0x4601 fasync_struct include/linux/fs.h |
| PTY_MAGIC 0x5001 (none at the moment) |
| drivers/char/pty.c |
| PPP_MAGIC 0x5002 ppp include/linux/if_ppp.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 |
| ESP_MAGIC 0x53ee esp_struct drivers/char/esp.h |
| TTY_MAGIC 0x5401 tty_struct include/linux/tty.h |
| TTY_DRIVER_MAGIC 0x5402 tty_driver include/linux/tty_driver.h |
| TTY_LDISC_MAGIC 0x5403 tty_ldisc include/linux/tty_ldisc.h |
| SPECIALIX_MAGIC 0x0907 specialix_port drivers/char/specialix_io8.h |
| CG_MAGIC 0x090255 ufs_cylinder_group include/linux/ufs_fs.h |
| RPORT_MAGIC 0x525001 r_port drivers/char/rocket_int.h |
| GDTIOCTL_MAGIC 0x06030f07 gdth_iowr_str drivers/scsi/gdth_ioctl.h |
| NBD_REQUEST_MAGIC 0x12560953 nbd_request include/linux/nbd.h |
| SLAB_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 |
| LSMAGIC 0x2a3b4d2a ls drivers/fc4/fc.c |
| LSOMAGIC 0x2a3c4e3c lso drivers/fc4/fc.c |
| WANPIPE_MAGIC 0x414C4453 sdla_{dump,exec} include/linux/wanpipe.h |
| CODA_CNODE_MAGIC 0x47114711 coda_inode_info include/linux/coda_fs_i.h |
| ISDN_ASYNC_MAGIC 0x49344C01 modem_info include/linux/isdn.h |
| ISDN_NET_MAGIC 0x49344C02 isdn_net_local_s include/linux/isdn.h |
| STLI_BOARDMAGIC 0x4bc6c825 stlibrd include/linux/istallion.h |
| SLAB_C_MAGIC 0x4f17a36d kmem_cache_s mm/slab.c |
| ROUTER_MAGIC 0x524d4157 wan_device include/linux/wanrouter.h |
| SLAB_RED_MAGIC1 0x5a2cf071 (any) mm/slab.c |
| STL_PORTMAGIC 0x5a7182c9 stlport include/linux/stallion.h |
| HDLCDRV_MAGIC 0x5ac6e778 hdlcdrv_state include/linux/hdlcdrv.h |
| EPCA_MAGIC 0x5c6df104 channel include/linux/epca.h |
| PCXX_MAGIC 0x5c6df104 channel drivers/char/pcxx.h |
| LO_MAGIC 0x68797548 nbd_device include/linux/nbd.h |
| STL_PANELMAGIC 0x7ef621a1 stlpanel include/linux/stallion.h |
| NBD_REPLY_MAGIC 0x96744668 nbd_reply include/linux/nbd.h |
| STL_BOARDMAGIC 0xa2267f52 stlbrd include/linux/stallion.h |
| SLAB_MAGIC_ALLOC 0xa5c32f2b kmem_slab_s mm/slab.c |
| SLAB_MAGIC_DESTROYED 0xb2f23c5a kmem_slab_s mm/slab.c |
| STLI_PORTMAGIC 0xe671c7a1 stliport include/linux/istallion.h |
| CCB_MAGIC 0xf2691ad2 ccb drivers/scsi/ncr53c8xx.c |