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highuid.txt: standardize document format Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - use a markup for the title; - use :Author: and :Last updated: markups at the beginning with authorship info; - use proper markups for the lists. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-15 00:51:39 +08:00
===================================================
Notes on the change from 16-bit UIDs to 32-bit UIDs
===================================================
:Author: Chris Wing <wingc@umich.edu>
:Last updated: January 11, 2000
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
- kernel code MUST take into account __kernel_uid_t and __kernel_uid32_t
when communicating between user and kernel space in an ioctl or data
structure.
- kernel code should use uid_t and gid_t in kernel-private structures and
code.
What's left to be done for 32-bit UIDs on all Linux architectures:
- Disk quotas have an interesting limitation that is not related to the
maximum UID/GID. They are limited by the maximum file size on the
underlying filesystem, because quota records are written at offsets
corresponding to the UID in question.
Further investigation is needed to see if the quota system can cope
properly with huge UIDs. If it can deal with 64-bit file offsets on all
architectures, this should not be a problem.
- Decide whether or not to keep backwards compatibility with the system
accounting file, or if we should break it as the comments suggest
(currently, the old 16-bit UID and GID are still written to disk, and
part of the former pad space is used to store separate 32-bit UID and
GID)
- Need to validate that OS emulation calls the 16-bit UID
compatibility syscalls, if the OS being emulated used 16-bit UIDs, or
uses the 32-bit UID system calls properly otherwise.
This affects at least:
highuid.txt: standardize document format Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - use a markup for the title; - use :Author: and :Last updated: markups at the beginning with authorship info; - use proper markups for the lists. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-15 00:51:39 +08:00
- iBCS on Intel
- sparc32 emulation on sparc64
(need to support whatever new 32-bit UID system calls are added to
sparc32)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
- Validate that all filesystems behave properly.
At present, 32-bit UIDs _should_ work for:
highuid.txt: standardize document format Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - use a markup for the title; - use :Author: and :Last updated: markups at the beginning with authorship info; - use proper markups for the lists. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-15 00:51:39 +08:00
- ext2
- ufs
- isofs
- nfs
- coda
- udf
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Ioctl() fixups have been made for:
highuid.txt: standardize document format Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - use a markup for the title; - use :Author: and :Last updated: markups at the beginning with authorship info; - use proper markups for the lists. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-15 00:51:39 +08:00
- ncpfs
- smbfs
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Filesystems with simple fixups to prevent 16-bit UID wraparound:
highuid.txt: standardize document format Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - use a markup for the title; - use :Author: and :Last updated: markups at the beginning with authorship info; - use proper markups for the lists. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-15 00:51:39 +08:00
- minix
- sysv
- qnx4
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Other filesystems have not been checked yet.
Fix "can not" in Documentation and Kconfig Randy brought it to my attention that in proper english "can not" should always be written "cannot". I donot see any reason to argue, even if I mightnot understand why this rule exists. This patch fixes "can not" in several Documentation files as well as three Kconfigs. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-04 04:53:09 +08:00
- The ncpfs and smpfs filesystems cannot presently use 32-bit UIDs in
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
all ioctl()s. Some new ioctl()s have been added with 32-bit UIDs, but
more are needed. (as well as new user<->kernel data structures)
- The ELF core dump format only supports 16-bit UIDs on arm, i386, m68k,
sh, and sparc32. Fixing this is probably not that important, but would
require adding a new ELF section.
- The ioctl()s used to control the in-kernel NFS server only support
16-bit UIDs on arm, i386, m68k, sh, and sparc32.
- make sure that the UID mapping feature of AX25 networking works properly
(it should be safe because it's always used a 32-bit integer to
communicate between user and kernel)