man/man2const/F_DUPFD.2const: HISTORY: Update first POSIX appearance of F_DUPFD(2const)

F_DUPFD(2const) first appeared in POSIX.1-1988.[1]

[1] IEEE Std 1003.1-1988, Table 6-1 "cmd Values for fcntl()".

Signed-off-by: Seth McDonald <sethmcmail@pm.me>
Message-ID: <24e850c16b1a16da197c3e86ec756a7f585ef732.1767599119.git.sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man5/gai.conf: Fix RFC reference

Most of the RFC references correctly reference 3484, but the entry
in scopev4 points to 3438 instead.  It references section 3.2,
which 3438 doesn't have, but 3484 does have and talks about IPv4
addresses so looks right.

Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
Message-ID: <20260104214956.258199-1-dg@treblig.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

CONTRIBUTING.d/security: Add instructions for reporting security incidents

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/socket.7: Fix documentation for SO_ATTACH_REUSEPORT_EBPF

When using eBPF, there are two possible cases depending on the program
type.  Only the first case was described.  In the second case, the
program should not return an index, but a decision (SK_PASS/SK_DROP).
The socket should be selected using the sk_select_reuseport helper.

Signed-off-by: Vincent Bernat <vincent@bernat.ch>
Message-ID: <20251201195726.3669864-1-vincent@bernat.ch>
Acked-by: Craig Gallek <kraig@google.com>
Message-ID: <CAEfhGiwbaAuvZ=aVQoRw8+ZQPmMQnwp3WFO5ELCMPJOOa3FnWQ@mail.gmail.com>
[alx: reorganize text more schematically]
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/F_GETSIG.2const: HISTORY: tfix

The G and S do look surprisingly similar...

Signed-off-by: Seth McDonald <sethmcmail@pm.me>
Message-ID: <2f33ba3b5bd29ebd931bd213fb8f9a7b19ed9ce6.1767072049.git.sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/sysctl.2: HISTORY: wfix

Include 4.4BSD in the initial list in HISTORY, rather than stating the
function's origin in 4.4BSD as a full sentence.  This is more concise
and consistent with other manual pages.

Signed-off-by: Seth McDonald <sethmcmail@pm.me>
Message-ID: <1477de655f76e1e6e85c12cb03c068b120704511.1767072049.git.sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/syscall.2: HISTORY: Add section

Move the description of syscall(2)'s first appearance from NOTES to a
new HISTORY section.

Signed-off-by: Seth McDonald <sethmcmail@pm.me>
Message-ID: <a2a2a51edeb0b23ebedf998cfac788dd96ee7ff3.1767072049.git.sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/mbsinit.3: wfix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/__riscv_flush_icache.3: wfix

Suggested-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3type/wint_t.3type: NAME: tfix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_RISCV_SET_ICACHE_FLUSH_CTX.2const: ffix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_SET_TIMERSLACK.2const: FILES: Remove section

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_RISCV_SET_ICACHE_FLUSH_CTX.2const: wfix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Fixes: ed40372bac58 (2024-07-22; "prctl.2: Add PR_RISCV_SET_ICACHE_FLUSH_CTX")
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_SET_FPEXC.2const: wfix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_SET_MM_EXE_FILE.2const: wfix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Fixes: 3612be041801 (2012-04-17; "prctl.2: Various edits and improvements to Cyrill's patch")
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man5/sysfs.5: /sys/module/: ffix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Fixes: 6df684e0d3e9 (2017-09-11; "sysfs.5: Various additions and improvements")
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man5/sysfs.5: /sys/module/parameters: Fix incomplete sentence

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Fixes: 6df684e0d3e9 (2017-09-11; "sysfs.5: Various additions and improvements")
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: Unify spelling of 'multiplexer'

Both 'o' and 'e' are used in the manual pages:

        $ grep -rho multiplex.r man/ | sort| uniq -c
              4 multiplexer
              4 multiplexor

Let's stick to 'e', for consistency with __NR_multiplexer.

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Acked-by: "G. Branden Robinson" <g.branden.robinson@gmail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: ffix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: pfix

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: Update linux.git/Documentation/ references

And remove some outdated ones.

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/address_families.7: DECnet support was removed in Linux 6.1

See the following commit:

linux.git 1202cdd66531 (2022-08-22; "Remove DECnet support from kernel")

The kernel documentation file, before it was removed, was
"Documentation/networking/decnet.rst".

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/bootparam.7: The IDE driver was removed in Linux 5.14

See the following commits:

linux.git b7fb14d3ac63 (2021-06-16; "ide: remove the legacy ide driver")
linux.git 898ee22c32be (2022-04-20; "Drop Documentation/ide/")

The kernel documentation file, before it was removed, was
"Documentation/ide/ide.rst".

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/semop.2: Rebrand VERSIONS as HISTORY

Rename the VERSIONS section to HISTORY.  It was actually documenting the
history of these APIs, and not different versions of it.

Fixes: 4131356cdab8 (2023-03-17; "man*/, man-pages.7: VERSIONS, STANDARDS, HISTORY: Reorganize sections")
Signed-off-by: Seth McDonald <sethmcmail@pm.me>
Message-ID: <86b4c2ec94334aadcc8abc9f17b34b60716d399b.1766641593.git.sethmcmail@pm.me>
[alx: split commit in two]
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/semop.2: VERSIONS: Fix incorrect history

Split semop(2) and semtimedop(2) in this section, and move the
previously listed standards/versions to the corresponding functions.

The VERSIONS section is really a HISTORY section that seems to have
mixed up semop(2) and semtimedop(2).  The relevant commit (4131356cdab8)
removed some context specifying which standards/versions apply to
semtimedop(2) only, causing this mix-up.  The diff for this commit on
man/man2/semop.2 is given below.

    $ git diff -U1 4131356cdab8^! man2/semop.2
    diff --git a/man2/semop.2 b/man2/semop.2
    index 7a1416a26..fe2906be4 100644
    --- a/man2/semop.2
    +++ b/man2/semop.2
    @@ -357,11 +357,8 @@ .SH ERRORS
     .IR semval .
    -.SH VERSIONS
    -.BR semtimedop ()
    -first appeared in Linux 2.5.52,
    -and was subsequently backported into Linux 2.4.22.
    -glibc support for
    -.BR semtimedop ()
    -first appeared in Linux 2.3.3.
     .SH STANDARDS
    -POSIX.1-2001, POSIX.1
    -2008, SVr4.
    +POSIX.1-2008.
    +.SH VERSIONS
    +Linux 2.5.52 (backported into Linux 2.4.22),
    +glibc 2.3.3.
    +POSIX.1-2001, SVr4.
     .\" SVr4 documents additional error conditions EINVAL, EFBIG, ENOSPC.

The removed information is restored on account of the semop(2) and
semtimedop(2) functions being described separately, removing the mix-up.

Fixes: 4131356cdab8 (2023-03-17; "man*/, man-pages.7: VERSIONS, STANDARDS, HISTORY: Reorganize sections")
Signed-off-by: Seth McDonald <sethmcmail@pm.me>
Message-ID: <86b4c2ec94334aadcc8abc9f17b34b60716d399b.1766641593.git.sethmcmail@pm.me>
[alx: split commit in two]
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/getopt_long.3: EXAMPLES: Add missing include

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/fmtmsg.3: EXAMPLES: Rename local variable

'class' is a keyword in C++.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/strncat.3: EXAMPLES: Use a more realistic example

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_RISCV_SET_ICACHE_FLUSH_CTX.2const: tfix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: grfix

The American spelling is far more common:

$ grep -rhio behavior man/ | wc -l
561
$ grep -rhio behaviour man/ | wc -l
31

This change was scripted:

$ grep -rl ehaviour man | xargs sed -i 's/ehaviour/ehavior/'

Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/mremap.2: ffix

Fixes: e3fcb6c76685 (2025-08-19; "man/man2/mremap.2: Describe multiple-mapping move")
Reported-by: Helge Kreutzmann <debian@helgefjell.de>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/ioctl_kd.2: Use uint8_t instead of char for bit masks

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: build-*-troff: Ignore adjustment diagnostics in standards.7

There's a very long URI that can't be adjusted.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: Add break point in URIs

Allow breaking URIs after ':' and before '//'.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Document IEEE names of POSIX revisions

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Add links

Many of these are published online; add those links.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Add links to online publications of POSIX.1

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Both ISO and IEC ratified these standards

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: POSIX.*: wfix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: ISO ratified POSIX.1 in 1996, not just POSIX.1b

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: C11: Document TC1

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: C99: Document TCs

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: ffix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Document K&R C

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Document C96

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Document C94

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Document C95

C95 added wide characters and other internationalization support.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: POSIX.1-2017: wfix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: SUSv4 2016 edition: wfix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: POSIX.1-2004 is formally POSIX.1-2001 2004 edition

And there's also POSIX.1-2001 2002 edition, although I can't find it
online.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: POSIX.1-2013 is formally POSIX.1-2008 2013 edition

Signed-off-by: Alejandro Colomar <alx@kernel.org>

etc/clang-tidy/config.yaml: Checks: -readability-use-concise-preprocessor-directives

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: $CLANG_CFLAGS: -Wno-implicit-void-ptr-cast

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: $CLANG_CFLAGS: -Wno-c++-unterminated-string-initialization

It triggers false positives with [[gnu::nonstring]].

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/getopt.3: ffix

Protect literals from hyphenation.

Signed-off-by: "G. Branden Robinson" <g.branden.robinson@gmail.com>
Message-ID: <20251219171602.6255ekvsx24ocub3@illithid>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/standards.7: Document C27, C23, POSIX.1-2004, POSIX.1-2013, POSIX.1-2024, SUSv5

Cc: Collin Funk <collin.funk1@gmail.com>
Reported-by: Seth McDonald <sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/statmount.2: Document that flags must be 0

Reading the man page for the first time, I assumed the lack of
mentioned flags meant that there weren't any, but I had to check the
kernel source to be sure.  Sure enough:

if (flags)
return -EINVAL;

Signed-off-by: Alyssa Ross <hi@alyssa.is>
Message-ID: <20251218230517.244704-1-hi@alyssa.is>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man7/rtnetlink.7: Document .ifi_change

This hasn't been "reserved for future use" since Linux 2.6.22, commit
83b496e928db (2007-05-22; "[RTNETLINK]: Allow changing of subsets of
netdevice flags in rtnl_setlink"), and it's used by iproute2.

Signed-off-by: Alyssa Ross <hi@alyssa.is>
Message-ID: <20251218185452.88205-1-hi@alyssa.is>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: <netdev@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/getopt_long.3: Document the equivalent of getopt(3)'s 'optopt'

Throw a bone to users of this function who need to report (in a
diagnostic message, for instance) the identity of an invalid long option
name.

Signed-off-by: "G. Branden Robinson" <g.branden.robinson@gmail.com>
Message-ID: <20251214013754.hvrmeblfbr3cb4he@illithid>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2/clone.2: ERRORS: Document E2BIG-based extension handshake

The clone3() system call uses copy_struct_from_user() and the E2BIG
error code to handle changes to the struct clone_args size.

Signed-off-by: Florian Weimer <fweimer@redhat.com>
Message-ID: <lhua4zkxccq.fsf@oldenburg.str.redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/updwtmp.3: logwtmp(): Rename function parameter

For consistency with utmp(5)'s ut_user.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/aligned_alloc.3: HISTORY: Document bogus specification from C11

Document the turbulent past of aligned_alloc(), and how libraries have
actually implemented it.

Fixes: 7fd1e0f2be21 (2023-05-20; "posix_memalign.3: Update aligned_alloc(3) to match C17")
Reported-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Reviewed-by: "G. Branden Robinson" <branden@debian.org>
Cc: Seth McDonald <sethmcmail@pm.me>
Cc: DJ Delorie <dj@redhat.com>
Cc: John Scott <jscott@posteo.net>
Cc: Paul Floyd <pjfloyd@wanadoo.fr>
Cc: <misc@openbsd.org>
Cc: Ingo Schwarze <schwarze@openbsd.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/memalign.3: wfix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: NOTES: Remove superfluous section

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: Remove redundant text

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: CAVEATS: Add section, and move paragraph to it

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/{aligned_alloc,posix_memalign}.3: Split aligned_alloc() from posix_memalign(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/{posix_memalign,valloc}.3: Split valloc() from posix_memalign(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/{posix_memalign,pvalloc}.3: Split pvalloc() from posix_memalign(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/{posix_,}memalign.3: Split memalign() from posix_memalign(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: STANDARDS: aligned_alloc() and posix_memalign() conform to POSIX.1-2024

Cc: Seth McDonald <sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: STANDARDS: aligned_alloc() conforms to C23

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: STANDARDS: aligned_alloc() conforms to C17, not C11

ISO C17 removed a restriction that was in place in C11.  This
documentation doesn't conform to C11; it conforms to C17.

Fixes: 7fd1e0f2be21 (2023-05-20; "posix_memalign.3: Update aligned_alloc(3) to match C17")
Reported-by: Seth McDonald <sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: wfix

Document aligned_alloc(3), and then say memalign(3) is equivalent,
instead of the other way around.  aligned_alloc(3) is the important one.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/posix_memalign.3: Remove confusing exception

This is already a requirement of memalign(3).  aligned_alloc(3)
is indeed exactly equivalent to memalign(3), since ISO C17.

Fixes: 7fd1e0f2be21 (2023-05-20; "posix_memalign.3: Update aligned_alloc(3) to match C17")
Reported-by: Seth McDonald <sethmcmail@pm.me>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/getopt_long*.3: Split getopt_long_only() from getopt_long(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/getopt_long.3: SYNOPSIS: Simplify feature test macro

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/getopt*.3: Split getopt_long*() from getopt(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/*s*printf.3: Split [v]sprintf() from snprintf(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man3/*printf.3: Split *s*printf() from printf(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man5/proc.5: Remove redundant paragraph

We already reference the manual pages by name.

Fixes: ba0d674b67d6 (2025-12-02; "man/man5/proc*.5: Add references to other proc*.5 pages")
Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: help-list-variables: Don't list undefined variables

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: $UNIQ: Add dependency

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: help-list-targets: Use 'make -n'

This makes the command more portable to arbitrary makefiles,
as one can run any target without fear of running any commands.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: help, help-*: Add targets to list targets, variables, and build dependencies

Suggested-by: Paolo Bonzini <bonzini@gnu.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

GNUmakefile: wsfix

Signed-off-by: Alejandro Colomar <alx@kernel.org>

share/mk/: $TR: Add dependency

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_SET_NAME.2const: SYNOPSIS: Fix prototype

The array may be narrower than that.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/PR_SET_NAME.2const: SYNOPSIS: tfix

Fixes: a4fc95108363 (2024-05-31; "prctl.2, PR_[SG]ET_NAME.2const: Split PR_[SG]ET_NAME from prctl(2)")
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man5/proc*.5: Add references to other proc*.5 pages

Fixes: 0569afbbccd6 (2023-08-17; "proc*.5: Make sashimi")
Reported-by: "Michael T. Kerrisk" <mtk.manpages@gmail.com>
Reported-by: Carlos O'Donell <carlos@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/: Make sashimi of ipv6(7)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/IPV6_V6ONLY.2const: Tweak after split

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/{IPPROTO_IPV6,IPV6_V6ONLY}.2const: Split IPV6_V6ONLY from IPPROTO_IPV6(2const)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/IPV6_UNICAST_HOPS.2const: Tweak after split

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/{IPPROTO_IPV6,IPV6_UNICAST_HOPS}.2const: Split IPV6_UNICAST_HOPS from IPPROTO_IPV6(2const)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/IPV6_ROUTER_ALERT.2const: Tweak after split

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/{IPPROTO_IPV6,IPV6_ROUTER_ALERT}.2const: Split IPV6_ROUTER_ALERT from IPPROTO_IPV6(2const)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/IPV6_RECVERR.2const: Tweak after split

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/{IPPROTO_IPV6,IPV6_RECVERR}.2const: Split IPV6_RECVERR from IPPROTO_IPV6(2const)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

man/man2const/IPV6_RTHDR.2const: Tweak after split

Signed-off-by: Alejandro Colomar <alx@kernel.org>