mirror of https://gitee.com/openkylin/linux.git
164 lines
10 KiB
ReStructuredText
164 lines
10 KiB
ReStructuredText
.. _magicnumbers:
|
|
|
|
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
|
|
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 them 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.
|
|
|
|
Changelog::
|
|
|
|
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
|
|
|
|
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
|
|
<pasky@ucw.cz>
|
|
03 Nov 2002
|
|
|
|
Updated the magic table to Linux 2.5.74.
|
|
|
|
Fabian Frederick
|
|
<ffrederick@users.sourceforge.net>
|
|
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``
|
|
===================== ================ ======================== ==========================================
|
|
|
|
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
|
|
OSS sound drivers have their magic numbers constructed from the soundcard PCI
|
|
ID - these are not listed here as well.
|
|
|
|
HFS is another larger user of magic numbers - you can find them in
|
|
``fs/hfs/hfs.h``.
|