man-pages-5.12 released

Gidday,

Alex Colomar and I are proud to announce:

man-pages-5.12 - man pages for Linux

This release resulted from patches, bug reports, reviews, and comments from around 40 contributors. The release includes around 300 commits that changed approximately 180 pages.

Tarball download:
http://www.kernel.org/doc/man-pages/download.html
Git repository:
https://git.kernel.org/cgit/docs/man-pages/man-pages.git/
Online changelog:

    http://man7.org/linux/man-pages/changelog.html#release_5.12

A short summary of the release is blogged at:
https://linux-man-pages.blogspot.com/2021/06/man-pages-512-released.html

The current version of the pages is browsable at:
http://man7.org/linux/man-pages/

You are receiving this message either because:

a) You contributed to the content of this release.

b) You are subscribed to [email protected] or [email protected].

c) I have information (possibly inaccurate) that you are the maintainer of a translation of the manual pages, or are the maintainer of the manual pages set in a particular distribution, or have expressed interest in helping with man-pages maintenance, or have otherwise expressed interest in being notified about man-pages releases. If you don't want to receive such messages from me, or you know of some other translator or maintainer who may want to receive such notifications, send me a message.

Cheers,

Michael

==================== Changes in man-pages-5.12 ====================

Released: 2021-06-20, Christchurch

Contributors
------------

The following people contributed patches/fixes or (noted in brackets in the changelog below) reports, notes, and ideas that have been incorporated in changes in this release:

Ahelenia Ziemiańska <[email protected]> Akihiro Motoki <[email protected]>
Alejandro Colomar <[email protected]> Alyssa Ross <[email protected]>
Aurelien Aptel <[email protected]>
Borislav Petkov <[email protected]>
Bruce Merry <[email protected]>
Chris Keilbart <[email protected]> Christian Brauner <[email protected]> Christoph Anton Mitterer <[email protected]> dann frazier <[email protected]> Dmitry V. Levin <[email protected]>
Florian Weimer <[email protected]>
Huang Ying <[email protected]>
Jakub Wilk <[email protected]>
James O. D. Hunt <[email protected]>
Jann Horn <[email protected]>
Johannes Berg <[email protected]>
Jon Murphy <[email protected]>
Josh Triplett <[email protected]> Katsuhiro Numata <[email protected]>
Kees Cook <[email protected]>
Mark Kettenis <[email protected]>
Mathieu Desnoyers <[email protected]> Michael Kerrisk <[email protected]>
Mike Rapoport <[email protected]>
Peter Xu <[email protected]>
Sargun Dhillon <[email protected]>
Stefan Puiu <[email protected]>
Štěpán Němec <[email protected]>
thomasavoss <[email protected]>
Topi Miettinen <[email protected]>
Tycho Andersen <[email protected]>
Utkarsh Singh <[email protected]> Vishwajith K <[email protected]>
Walter Harms <[email protected]>
Yang Xu <[email protected]>
Zhiheng Li <[email protected]>
наб <[email protected]>

Apologies if I missed anyone!

New and rewritten pages
-----------------------

seccomp_unotify.2
Michael Kerrisk [Tycho Andersen, Jann Horn, Kees Cook, Christian Brauner
Sargun Dhillon]
New page documenting the seccomp user-space notification mechanism

MAX.3
Alejandro Colomar
New page to document MAX() and MIN()

Newly documented interfaces in existing pages
---------------------------------------------

seccomp.2
Tycho Andersen [MichaelKerrisk]
Document SECCOMP_GET_NOTIF_SIZES
Tycho Andersen
Document SECCOMP_FILTER_FLAG_NEW_LISTENER [Michael Kerrisk]
Tycho Andersen
Document SECCOMP_RET_USER_NOTIF [Michael Kerrisk]

set_mempolicy.2
Huang Ying [Alejandro Colomar, "Huang, Ying"]
Add mode flag MPOL_F_NUMA_BALANCING

userfaultfd.2
Peter Xu [Alejandro Colomar, Mike Rapoport]
Add UFFD_FEATURE_THREAD_ID docs
Peter Xu [Alejandro Colomar, Mike Rapoport]
Add write-protect mode docs

proc.5
Michael Kerrisk
Document /proc/sys/vm/sysctl_hugetlb_shm_group

system_data_types.7
Alejandro Colomar
Add 'blksize_t'
Alejandro Colomar
Add 'blkcnt_t'
Alejandro Colomar
Add 'mode_t'
Alejandro Colomar
Add 'struct sockaddr'
Alejandro Colomar
Add 'cc_t'
Alejandro Colomar
Add 'socklen_t'

New and changed links
---------------------

blkcnt_t.3
Alejandro Colomar
New link to system_data_types(7)

blksize_t.3
Alejandro Colomar
New link to system_data_types(7)

cc_t.3
Alejandro Colomar
New link to system_data_types(7)

MIN.3
Michael Kerrisk
New link to MIN.3

mode_t.3
Alejandro Colomar
New link to system_data_types(7)

sockaddr.3
Alejandro Colomar
New link to system_data_types(7)

socklen_t.3
Alejandro Colomar
New link to system_data_types(7)

Global changes
--------------

Many pages
Alejandro Colomar
SYNOPSIS: Use syscall(SYS_...); for system calls without a wrapper

Many pages
Alejandro Colomar
SYNOPSIS: Document why each header is required

Many pages
Alejandro Colomar
SYNOPSIS: Remove unused includes

Various pages
Alejandro Colomar
Add note about the use of syscall(2)

Various pages
Alejandro Colomar
SYNOPSIS: Miscellaneous fixes to includes

A few pages
Alejandro Colomar
SYNOPSIS: Add missing 'const'

Changes to individual pages
---------------------------

dup.2
Michael Kerrisk
Rewrite the description of dup() somewhat
As can be seen by any number of StackOverflow questions, people persistently misunderstand what dup() does, and the existing manual page text, which talks of "copying" a file descriptor doesn't help. Rewrite the text a little to try to prevent some of these misunderstandings, in particular noting at the start that dup() allocates a new file descriptor.
Michael Kerrisk
Clarify what silent closing means
Alejandro Colomar
SYNOPSIS: Use consistent comments through pages

epoll_wait.2
Alejandro Colomar
Move misplaced subsection to NOTES from BUGS

execveat.2
Michael Kerrisk
Library support has been added in glibc 2.34

_exit.2
Michael Kerrisk
Add a little more detail on the raw _exit() system cal

exit_group.2
Alejandro Colomar
Use 'noreturn' in prototypes

flock.2
Aurelien Aptel [Alejandro Colomar]
Add CIFS details
CIFS flock() locks behave differently than the standard. Give an overview of those differences.

ioperm.2
Alejandro Colomar
Remove obvious comment

memfd_create.2
mmap.2
shmget.2
Michael Kerrisk [Yang Xu]
Document the EPERM error for huge page allocations
This error can occur if the caller is does not have CAP_IPC_LOCK and is not a member of the sysctl_hugetlb_shm_group.

mmap.2
Bruce Merry
Clarify that MAP_POPULATE is best-effort

mount.2
Topi Miettinen
Document SELinux use of MS_NOSUID mount flag

open.2
Alejandro Colomar [Walter Harms]
Fix bug in linkat(2) call example
AT_EMPTY_PATH works with empty strings (""), but not with NULL (or at least it's not obvious).
Michael Kerrisk
Make it clearer that an FD is an index into the process's FD table
Sometimes people are confused, thinking a file descriptor is just a number....

perfmonctl.2
Michael Kerrisk
This system call was removed in Linux 5.10

pipe.2
Alejandro Colomar
SYNOPSIS: Fix incorrect prototype
Michael Kerrisk
Rearrange SYNOPSIS so that minority version pipe() is at end

ptrace.2
Dmitry V. Levin [Alejandro Colomar, Mathieu Desnoyers]
Mention PTRACE_GET_SYSCALL_INFO in RETURN VALUE section

seccomp.2
Michael Kerrisk
Reorder list of SECCOMP_SET_MODE_FILTER flags alphabetically
(No content changes.)
Michael Kerrisk
SEE ALSO: add seccomp_unotify(2)

select.2
Michael Kerrisk
Strengthen the warning regarding the low value of FD_SETSIZE
All modern code should avoid select(2) in favor of poll(2) or epoll(7).
Michael Kerrisk
Relocate sentence about the fd_set value-result arguments to BUGS

syscalls.2
Michael Kerrisk
perfmonctl(2) was removed in Linux 5.10

bswap.3
Alejandro Colomar
bswap_*() are implemented using functions
Even though it's true that they are macros, it's transparent to the user.

The user will see their results casted to unsigned types after the conversion due to the underlying functions, so it's better to document these as the underlying functions, specifying the types.

cmsg.3
unix.7
Michael Kerrisk
Refer to seccomp_unotify(2) for an example of SCM_RIGHTS usage

cpow.3
Alejandro Colomar
Use 'complex' after the type consistently

ctime.3
Michael Kerrisk [Katsuhiro Numata]
Restore documentation of 'tm_gmtoff' field

errno.3
Alejandro Colomar [Florian Weimer, Mark Kettenis]
Fix ENODATA text
ENODATA is an XSI STREAMS extension (not base POSIX).

exec.3
Josh Triplett [Alejandro Colomar]
Clarify that execvpe() uses PATH from the caller, not envp
Josh Triplett [Alejandro Colomar]
Fix description of 'e' variants
The envp argument specifies the environment of the new process image, not "the environment of the caller".

fflush.3
Alejandro Colomar
SEE ALSO: Add fpurge(3)

getline.3
наб [Ahelenia Ziemiańska, Alejandro Colomar]
!*lineptr is sufficient
No implementation or spec requires *n to be 0 to allocate a new buffer.

getopt.3
James O. D. Hunt [Alejandro Colomar]
Clarify behaviour

printf.3
Utkarsh Singh [Alejandro Colomar]
Add overall structure of format string

pthread_attr_setinheritsched.3
pthread_attr_setschedparam.3
Alejandro Colomar
SYNOPSIS: Use 'restrict' in prototypes

pthread_mutexattr_setrobust.3
Michael Kerrisk
Note that the *_np() APIs are deprecated since glibc 2.34
Alejandro Colomar
SYNOPSIS: Remove incorrect 'const'

pthread_mutex_consistent.3
Michael Kerrisk
Note that pthread_mutexattr_setrobust() is now deprecated

pthread_yield.3
Michael Kerrisk
Note that this function is deprecated since glibc 2.34

rpc.3
Alejandro Colomar
SYNOPSIS: Fix prototypes (misc.)

scanf.3
Alyssa Ross [Alejandro Colomar]
Clarify that %n supports type modifiers

xdr.3
Alejandro Colomar
SYNOPSIS: Fix prototype types
Use the same types glibc uses, and add a missing 'const'.

capabilities.7
Michael Kerrisk
CAP_IPC_LOCK also governs memory allocation using huge pages

environ.7
Josh Triplett [Alejandro Colomar]
Remove obsolete admonishment of the GZIP environment variable

kernel_lockdown.7
dann frazier [Alejandro Colomar]
Remove description of lifting via SysRq (not upstream)
The patch that implemented lockdown lifting via SysRq ended up getting dropped[*] before the feature was merged upstream. Having the feature documented but unsupported has caused some confusion for our users.

mount_namespaces.7
namespaces.7
Michael Kerrisk
Relocate reference to pam_namespace(8) from namespaces.7 to mount_namespaces.7.

signal.7
Michael Kerrisk
Add reference to seccomp_unotify(2)
The seccomp user-space notification feature can cause changes in the semantics of SA_RESTART with respect to system calls that would never normally be restarted. Point the reader to the page that provide further details.

vsock.7
Alyssa Ross
ioctls are on /dev/vsock, not sockets

Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/