POSIX AIO is great, but it lacks vectored I/O functions. This commit
fixes that shortcoming by adding aio_writev and aio_readv. They aren't
part of the standard, but they're an obvious extension. They work just
like their synchronous equivalents pwritev and preadv.
It isn't yet possible to use vectored aiocbs with lio_listio, but that
could be added in the future.
Reviewed by: jhb, kib, bcr
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D27743
PR#252358 reported a serious performance problem w.r.t.
cp(1) when copying large non-sparse files.
This problem appears to have been caused by cp(1)
calling copy_file_range(2) with a small "len" argument.
This patch adds a recommendation to use a large "len"
value where possible, for performance reasons.
Reviewed by: asomers
Differential Revision: https://reviews.freebsd.org/D27935
- varios "new sentence, new line" warnings
- varios "sections out of conventional order" warnings
- varios "unusual Xr order" warnings
- varios "missing section argument" warnings
- varios "no blank before trailing delimiter" warnings
- varios "normalizing date format" warnings
MFC after: 1 month
Sort by manpage section, then sort entries alphabetically.
This makes the manpages `make manlint` clean.
MFC after: 1 week
Sponsored by: DellEMC Isilon
Months should be fully spelled as their local-specific equivalents: in this
case `Oct` should have been spelled like `October`.
Reported by: make manlint
MFC after: 1 week
Sponsored by: DellEMC Isilon
The CAVEATS section was misspelled as "CAVEAT" before this change. Fix the
spelling to identify issues related to the section.
Furthermore, given that the section order was incorrect, move the CAVEATS
section down to the bottom of the manpage, per the conventional section
order.
MFC after: 1 week
Reported by: make manlint
Sponsored by: DellEMC Isilon
This is being done for the formatting and context changes. While the net content
hasn't been changed, the content/context changes were sufficient to warrant the
date bump.
MFC after: 1 week
MFC with: r368431, r368433, r368434, r368435
Sponsored by: DellEMC Isilon
While some of the syscalls' behavior were documented and implied in the
RETURN VALUES section by earlier, e.g., the DESCRIPTION sections, as having
behavior of the other calls (`*_fd` vs `*_file` vs `*_link`), there was a lot
of implied return value behavior in the section prior to this change.
Explicitly document the syscall behavior per the current implementation in
sys/kern/vfs_extattr.c so others can better develop based on its explicit
documented behavior instead of having to digest the context of the manpage to
understand the appropriate behavior.
MFC after: 1 week
MFC with: r368431, r368433, r368434
Sponsored by: DellEMC Isilon
- Remove an unnecessary trailing comma separating a two-item clause.
- Sort more function calls alphabetically (in the same vein as r368433).
MFC after: 1 week
Sponsored by: DellEMC Isilon
Although some sections of the manpage sort the syscalls alphabetically, many
core areas of the manpage do not. Sort the syscalls so it is easier to pick out
functional changes and to improve manpage readability.
This formatting change is also being done to make future functional changes
easier to spot.
MFC after: 1 week
Sponsored by: DellEMC Isilon
The date with .Dd prior to this change isn't canonically spelled out: it
should have been "December", not "Dec".
MFC after: 1 week
Sponsored by: DellEMC Isilon
- The CAVEATS section was misspelled as "CAVEAT".
- The CAVEATS section should come before the "BUGS" section and after
other existing sections by convention.
MFC after: 1 week
Reported by: make manlint
Sponsored by: DellEMC Isilon
This clever technique to get a time remaining back was added to support sem_clockwait_np.
Reviewed by: kib, vangyzen
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D27160
Foundation copyrights, approved by emaste@. It does not include
files which carry other people's copyrights; if you're one
of those people, feel free to make similar change.
Reviewed by: emaste, imp, gbe (manpages)
Differential Revision: https://reviews.freebsd.org/D26980
This also fixes a minor issue that was missed in the initial review; the
layout of the MFD_HUGE_* flags is actually not 1:1 bit:flag -- it instead
borrowed the Linux convention of how this is laid out since it was
originally implemented on Linux, the top 6 bits represent the shift required
for the requested page size.
This allows us to remove the flag <-> pgsize mapping table and simplify the
logic just prior to validation of the requested page size.
While we're here, fix two small nits:
- HUGETLB memfd shouldn't exhibit the SHM_GROW_ON_WRITE behavior. We can
only grow largepage shm by appropriately aligned (i.e. requested pagesize)
sizes, so it can't work in the typical/sane fashion. Furthermore, Linux
does the same, so let's be compatible.
- We don't allow MFD_HUGETLB without specifying a pagesize, so no need to
check for that later.
Reviewed by: kib (slightly earlier version)
Literally returning EINVAL from a function designed to return an fd makes
for interesting scenarios.
I cannot assign enough pointy hats to cover this one.
r365524 did accidentally invert this check that sets SHM_LARGEPAGE, leading
non-hugetlb memfd as unconfigured largepage shm and thus test failures when
we try to ftruncate or write to them.
PR: 249236
Discussed with: kib
largepage shm objects.
And since we can, add memfd_create(MFD_HUGETLB) support, hopefully
close enough to the Linux feature.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24652
getlogin_r is specified by POSIX to to take a size_t len, not int. Fix our
version to do the same, bump the symbol version due to ABI change and
provide compat.
This was reported to break compilation of Ruby 2.8.
Some discussion about the necessity of the ABI compat did take place in the
review. While many 64-bit platforms would likely be passing it in a 64-bit
register and zero-extended and thus, not notice ABI breakage, some do
sign-extend (e.g. mips).
PR: 247102
Submitted by: Bertram Scharpf <software@bertram-scharpf.de> (original)
Submitted by: cem (ABI compat)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D26335
Currently we use a single bit to indicate whether the virtual page is
part of a superpage. To support a forthcoming implementation of
non-transparent 1GB superpages, it is useful to provide more detailed
information about large page sizes.
The change converts MINCORE_SUPER into a mask for MINCORE_PSIND(psind)
values, indicating a mapping of size psind, where psind is an index into
the pagesizes array returned by getpagesizes(3), which in turn comes
from the hw.pagesizes sysctl. MINCORE_PSIND(1) is equal to the old
value of MINCORE_SUPER.
For now, two bits are used to record the page size, permitting values
of MAXPAGESIZES up to 4.
Reviewed by: alc, kib
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26238
In certain situations lseek(2) will return successful although if no seek
was performed. This can happen when operating on devices that don't support
seeking (older tape drives) or when operating on changeable media devices
(such as DVD or Blu-ray devices) without a medium inserted.
Document this within the man page and update the POSIX compliance while here.
PR: 162765
Submitted by: arundel@
Reported by: arundel@
Reviewed by: bcr (mentor)
Approved by: bcr (mentor)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25646
Some older references called it 'arg'
Also fix a syntax error that was underlining an entire sentence.
PR: 247386
Reported by: Paul Floyd <paulf@free.fr>, PauAmma (research)
MFC after: 2 weeks
Sponsored by: Klara Inc.
memfd_create fds will no longer require an ftruncate(2) to set the size;
they'll grow (to the extent that it's possible) upon write(2)-like syscalls.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D25502
While this behaviour is harmless, it is really just an artifact of the
fact that the msgctl(2) implementation uses a user-visible structure as
part of the internal implementation, so it is not deliberate and these
pointers are not useful to userspace. Thus, NULL them out before
copying out, and remove references to them from the manual page.
Reported by: Jeffball <jeffball@grimm-co.com>
Reviewed by: emaste, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D25600
- Add STANDARDS and HISTORY sections within the appropriate manpages
- Mention two USENIX papers within kqueue(2) and strlcpy(3)
Reviewed by: bcr (mentor)
Approved by: bcr (mentor)
Obtained from: NetBSD
MFC after: 7 days
Differential Revision: https://reviews.freebsd.org/D24650
This commit adds the priv(9) that waters down the sysctl to make it only
allow read(2) of a dirfd by the system root. Jailed root is not allowed, but
jail policy and superuser policy will abstain from allowing/denying it so
that a MAC module can fully control the policy.
Such a MAC module has been written, and can be found at:
https://people.freebsd.org/~kevans/mac_read_dir-0.1.0.tar.gz
It is expected that the MAC module won't be needed by many, as most only
need to do such diagnostics that require this behavior as system root
anyways. Interested parties are welcome to grab the MAC module above and
create a port or locally integrate it, and with enough support it could see
introduction to base. As noted in mac_read_dir.c, it is released under the
BSD 2 clause license and allows the restrictions to be lifted for only
jailed root or for all unprivileged users.
PR: 246412
Reviewed by: mckusick, kib, emaste, jilles, cy, phk, imp (all previous)
Reviewed by: rgrimes (latest version)
Differential Revision: https://reviews.freebsd.org/D24596
Historically, we've allowed read() of a directory and some filesystems will
accommodate (e.g. ufs/ffs, msdosfs). From the history department staffed by
Warner: <<EOF
pdp-7 unix seemed to allow reading directories, but they were weird, special
things there so I'm unsure (my pdp-7 assembler sucks).
1st Edition's sources are lost, mostly. The kernel allows it. The
reconstructed sources from 2nd or 3rd edition read it though.
V6 to V7 changed the filesystem format, and should have been a warning, but
reading directories weren't materially changed.
4.1b BSD introduced readdir because of UFS. UFS broke all directory reading
programs in 1983. ls, du, find, etc all had to be rewritten. readdir() and
friends were introduced here.
SysVr3 picked up readdir() in 1987 for the AT&T fork of Unix. SysVr4 updated
all the directory reading programs in 1988 because different filesystem
types were introduced.
In the 90s, these interfaces became completely ubiquitous as PDP-11s running
V7 faded from view and all the folks that initially started on V7 upgraded
to SysV. Linux never supported this (though I've not done the software
archeology to check) because it has always had a pathological diversity of
filesystems.
EOF
Disallowing read(2) on a directory has the side-effect of masking
application bugs from relying on other implementation's behavior
(e.g. Linux) of rejecting these with EISDIR across the board, but allowing
it has been a vector for at least one stack disclosure bug in the past[0].
By POSIX, this is implementation-defined whether read() handles directories
or not. Popular implementations have chosen to reject them, and this seems
sensible: the data you're reading from a directory is not structured in some
unified way across filesystem implementations like with readdir(2), so it is
impossible for applications to portably rely on this.
With this patch, we will reject most read(2) of a dirfd with EISDIR. Users
that know what they're doing can conscientiously set
bsd.security.allow_read_dir=1 to allow read(2) of directories, as it has
proven useful for debugging or recovery. A future commit will further limit
the sysctl to allow only the system root to read(2) directories, to make it
at least relatively safe to leave on for longer periods of time.
While we're adding logic pertaining to directory vnodes to vn_io_fault, an
additional assertion has also been added to ensure that we're not reaching
vn_io_fault with any write request on a directory vnode. Such request would
be a logical error in the kernel, and must be debugged rather than allowing
it to potentially silently error out.
Commented out shell aliases have been placed in root's chsrc/shrc to promote
awareness that grep may become noisy after this change, depending on your
usage.
A tentative MFC plan has been put together to try and make it as trivial as
possible to identify issues and collect reports; note that this will be
strongly re-evaluated. Tentatively, I will MFC this knob with the default as
it is in HEAD to improve our odds of actually getting reports. The future
priv(9) to further restrict the sysctl WILL NOT BE MERGED BACK, so the knob
will be a faithful reversion on stable/12. We will go into the merge
acknowledging that the sysctl default may be flipped back to restore
historical behavior at *any* point if it's warranted.
[0] https://www.freebsd.org/security/advisories/FreeBSD-SA-19:10.ufs.asc
PR: 246412
Reviewed by: mckusick, kib, emaste, jilles, cy, phk, imp (all previous)
Reviewed by: rgrimes (latest version)
MFC after: 1 month (note the MFC plan mentioned above)
Relnotes: absolutely, but will amend previous RELNOTES entry
Differential Revision: https://reviews.freebsd.org/D24596
One of the error descriptions referred to permissions; in context the
meaning was probably clear, but the prot values are properly called
protections.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
