Documentation/staging/magic-number.rst

Source file repositories/reference/linux-study-clean/Documentation/staging/magic-number.rst

File Facts

System
Linux kernel
Corpus path
Documentation/staging/magic-number.rst
Extension
.rst
Size
3316 bytes
Lines
82
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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/uapi/linux/pg.h``
APM_BIOS_MAGIC        0x4101           apm_user                 ``arch/x86/kernel/apm_32.c``
FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip/slip.h``
KV_MAGIC              0x5f4b565f       kernel_vars_s            ``arch/mips/include/asm/sn/klkernvars.h``
CODA_MAGIC            0xC0DAC0DA       coda_file_info           ``fs/coda/coda_fs_i.h``
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``
NMI_MAGIC             0x48414d4d455201 nmi_s                    ``arch/mips/include/asm/sn/nmi.h``
===================== ================ ======================== ==========================================

Annotation

Implementation Notes