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authorSeongJae Park <sj@kernel.org>2024-06-24 11:53:08 -0700
committerJonathan Corbet <corbet@lwn.net>2024-06-26 16:36:00 -0600
commitf9a4f4a0e1f5d8033d30d50f59ada1666a5cf38d (patch)
tree35d967cd3853e2d081309cafe327593cfc4a0e40 /Documentation/process
parent7400d25a0a5cb2a1a782c4c49e6c8f883e5184d0 (diff)
downloadlwn-f9a4f4a0e1f5d8033d30d50f59ada1666a5cf38d.tar.gz
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Docs: Move magic-number from process to staging
'Other material' section on 'process/index' is for unsorted documents. However we also have a dedicated place for the purpose, 'staging/'. Move 'magic-number' from the section to 'staging/' directory. Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240624185312.94537-4-sj@kernel.org
Diffstat (limited to 'Documentation/process')
-rw-r--r--Documentation/process/index.rst1
-rw-r--r--Documentation/process/magic-number.rst84
2 files changed, 0 insertions, 85 deletions
diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst
index 08b4eb1e9118..fb089bf9d6a8 100644
--- a/Documentation/process/index.rst
+++ b/Documentation/process/index.rst
@@ -113,7 +113,6 @@ lack of a better place.
.. toctree::
:maxdepth: 1
- magic-number
clang-format
.. only:: subproject and html
diff --git a/Documentation/process/magic-number.rst b/Documentation/process/magic-number.rst
deleted file mode 100644
index 7029c3c084ee..000000000000
--- a/Documentation/process/magic-number.rst
+++ /dev/null
@@ -1,84 +0,0 @@
-.. _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``
-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.h``
-BAYCOM_MAGIC 0x19730510 baycom_state ``drivers/net/baycom_epp.c``
-HDLCDRV_MAGIC 0x5ac6e778 hdlcdrv_state ``include/linux/hdlcdrv.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``
-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``
-NMI_MAGIC 0x48414d4d455201 nmi_s ``arch/mips/include/asm/sn/nmi.h``
-===================== ================ ======================== ==========================================