diff options
author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-27 14:56:51 -0300 |
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committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-15 11:03:02 -0300 |
commit | 4f4cfa6c560c93ba180c30675cf845e1597de44c (patch) | |
tree | 0bbe2ec9e6ef62ed2a347504dda50c6bdbe43703 /Documentation/highuid.txt | |
parent | da82c92f1150f66afabf78d2c85ef9ac18dc6d38 (diff) |
docs: admin-guide: add a series of orphaned documents
There are lots of documents that belong to the admin-guide but
are on random places (most under Documentation root dir).
Move them to the admin guide.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'Documentation/highuid.txt')
-rw-r--r-- | Documentation/highuid.txt | 80 |
1 files changed, 0 insertions, 80 deletions
diff --git a/Documentation/highuid.txt b/Documentation/highuid.txt deleted file mode 100644 index 6ee70465c0ea..000000000000 --- a/Documentation/highuid.txt +++ /dev/null @@ -1,80 +0,0 @@ -=================================================== -Notes on the change from 16-bit UIDs to 32-bit UIDs -=================================================== - -:Author: Chris Wing <wingc@umich.edu> -:Last updated: January 11, 2000 - -- 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: - - - iBCS on Intel - - - sparc32 emulation on sparc64 - (need to support whatever new 32-bit UID system calls are added to - sparc32) - -- Validate that all filesystems behave properly. - - At present, 32-bit UIDs _should_ work for: - - - ext2 - - ufs - - isofs - - nfs - - coda - - udf - - Ioctl() fixups have been made for: - - - ncpfs - - smbfs - - Filesystems with simple fixups to prevent 16-bit UID wraparound: - - - minix - - sysv - - qnx4 - - Other filesystems have not been checked yet. - -- The ncpfs and smpfs filesystems cannot presently use 32-bit UIDs in - 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) |