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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2016-09-21 22:18:36 +0200
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2016-10-24 12:12:35 +0200
commit9a11e15381b3503e51c4bbab4f9dad7c001f7c94 (patch)
tree0cc97fddcc702d5417f72f0034c7b20b0b31f0a0 /Documentation/magic-number.txt
parentDocumentation/init.txt: convert to ReST markup (diff)
downloadlinux-9a11e15381b3503e51c4bbab4f9dad7c001f7c94.tar.xz
linux-9a11e15381b3503e51c4bbab4f9dad7c001f7c94.zip
Documentation/magic-number.txt: convert it to ReST markup
- add a title for the document; - convert the table; - use quote block for the changelog; - use monotonic fonts for file names; - adjust whitespaces and blank lines; - add it to the user's book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/magic-number.txt')
-rw-r--r--Documentation/magic-number.txt216
1 files changed, 111 insertions, 105 deletions
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
<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.
+ 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.
+ 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.
+ 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
+===================== ================ ======================== ==========================================
+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``.