Reimplement bdf0f24bb1 by checking for the caller' ABI in
the implementation of PT_GET_SC_ARGS, and copying out everything if
it is Linuxolator.
Also fix a minor information leak: if PT_GET_SC_ARGS_ALL is done on the
thread reused after other process, it allows to read some number of that
thread last syscall arguments. Clear td_sa.args in thread_alloc().
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D31968
GCC only added support for __has_builtin in GCC 10. However, all
supported versions of GCC and clang include these builtins so just use
them unconditionally.
This fixes the build with GCC 9.
Reviewed by: manu, hselasky, imp
Differential Revision: https://reviews.freebsd.org/D31942
This is one of the pieces required to make modern (ie Focal)
strace(1) work.
Reviewed By: jhb (earlier version)
Sponsored by: EPSRC
Differential Revision: https://reviews.freebsd.org/D28212
Switch the main syscall table to use CAPENABLED flags rather than
capabilities.conf. This avoid synchronization issues between
syscalls.master and capabilities.conf (e.g. when renaming a syscall
during development).
For now, move capabilities.conf to sys/compat/freebsd32 and use it
there. Use of sys/compat/freebsd32/syscalls.master should be replaced
by makesyscalls.lua enhancements to allow the main one to be used.
This change results in no changes to generated files after running
`make sysent`.
Reviewed by: kevans, emaste
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D31350
Move the common kernel function signatures from machine/reg.h to a new
sys/reg.h. This is in preperation for adding PT_GETREGSET to ptrace(2).
Reviewed by: imp, markj
Sponsored by: DARPA, AFRL (original work)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19830
CLONE_CLEAR_SIGHAND is designed to reset all signal handlers of the child
not set to SIG_IGN to SIG_DFL.
Reviewed by: kib
Differential revision: https://reviews.freebsd.org/D31481
MFC after: 2 weeks
In preparation for clone3 system call add struct clone_args and use it in
clone implementation.
Move all of clone related bits to the newly created linux_fork.h header.
Differential revision: https://reviews.freebsd.org/D31474
MFC after: 2 weeks
At least Linux x86 ABI's does not use carry bit and expects that the dx register
is preserved. For this add a new sv_set_fork_retval hook and call it from cpu_fork().
Add a short comment about touching dx in x86_set_fork_retval(), for more details
see phab comments from kib@ and imp@.
Reviewed by: kib
Differential revision: https://reviews.freebsd.org/D31472
MFC after: 2 weeks
As no more NetBSD code in futexes exists replace NetBSD copyrights by
standard FreeBSD 2 clause license.
Add Roman Divacky's copyrights as an author of the robust futexes.
Differential revision: https://reviews.freebsd.org/D31347
MFC after: 2 weeks
These ones were unambiguous cases where the Foundation was the only
listed copyright holder (in the associated license block).
Sponsored by: The FreeBSD Foundation
fspacectl(2) is a system call to provide space management support to
userspace applications. VOP_DEALLOCATE(9) is a VOP call to perform the
deallocation. vn_deallocate(9) is a public KPI for kmods' use.
The purpose of proposing a new system call, a KPI and a VOP call is to
allow bhyve or other hypervisor monitors to emulate the behavior of SCSI
UNMAP/NVMe DEALLOCATE on a plain file.
fspacectl(2) comprises of cmd and flags parameters to specify the
space management operation to be performed. Currently cmd has to be
SPACECTL_DEALLOC, and flags has to be 0.
fo_fspacectl is added to fileops.
VOP_DEALLOCATE(9) is added as a new VOP call. A trivial implementation
of VOP_DEALLOCATE(9) is provided.
Sponsored by: The FreeBSD Foundation
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D28347
Fix a bug that slipped in in 90707c4e44
using the correct field in le32p_replace_bits().
MFC after: 3 days
Reviewed by: hselasky
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31352
FUTEX_LOCK_PI2 was added to support clock selection as FUTEX_LOCK_PI uses a
CLOCK_REALTIME based absolute value since it was implemented, but it does not
require that the FUTEX_CLOCK_REALTIME bit is set, because that was introduced
later.
MFC after: 2 weeks
In the Linux emulation layer linux_tdfind() has a special purpose to
handle glibc specific TID mangling and we should use it instead of tdfind().
MFC after: 2 weeks
Handle some races in handle_futex_death() which can prevents a wakeup of
potential waiters which can cause these waiters to block forever.
Differential Revision: https://reviews.freebsd.org/D31280
MFC after: 2 weeks
Linux futex documentation explicitly states that EINVAL is returned if
the futex is not 4-byte aligned. Check futex alignment as a Linux do
and return EINVAL.
Differential Revision: https://reviews.freebsd.org/D31279
MFC after: 2 weeks
Follow the r349951 (30b3018d), add check to react to stops and requests
to terminate between retries.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31254
MFC after: 2 weeks
According to fetch(9) fueword facility designed to fetch atomically
small amount of data from user space.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31239
MFC after: 2 weeks
To prevent umtx.h polluting by future changes split it on two headers:
umtx.h - ABI header for userspace;
umtxvar.h - the kernel staff.
While here fix umtx_key_match style.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31248
MFC after: 2 weeks
gcc failed as it didn't inlined the builtins and generates calls to
the libgcc, ld can't find libgcc as cross-toolchain libgcc is not installed.
To avoid this add internal vDSO ffs functions without optimized builtins.
Reported by: jhb
MFC after: 2 weeks
Add an implementation of read_poll_timeout() and the atomic variant
which I did at some point last year for rtw88 and now updated based
on feedback.
MFC after: 10 days
Reviewed by: hsealsky
Differential Revision: https://reviews.freebsd.org/D30980
Add fsleep() function now required by rtw88. This seems to be
making a decision depending on time to sleep on how to sleep.
Given our compat framework already is lenient on how long to sleep,
this is a cut down version.
MFC after: 10 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D31322
Add sys/types.h to dmi.h and do not rely on other files to include
all needed headers in Linux land. I ran into compile problems with
rtw88 otherwise.
MFC after: 3 days
to restore ABI compatibility for pre-10.x binaries.
It restores _umtx_lock() and _umtx_unlock() syscalls, and UMTX_OP_LOCK/
UMTX_OP_UNLOCK umtx_op(2) operations. UMUTEX_ERROR_CHECK flag is left
out for now, I do not think it makes a difference.
PR: 218571
Reviewed by: brooks (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31220
Use thread_reap_barrier() to ensure that no threads are kept in the
zombies list which could have the linuxkpi task allocated.
Also fix order of initialization and teardown for current task
allocation hooks and resources. Register current task allocator after
zones are initialized. Deregister allocator before cycling over threads
and zeroing task pointer.
Reviewed by: hselasky, markj
Sponsored by: Mellanox Technologies/NVidia Networking
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30468
Add sign_extend32() replicating the 64 version. This is needed by
the rtw88 driver.
MFC after: 10 days
Reviewed by: imp, emaste, hselasky
Differential Revision: https://reviews.freebsd.org/D30979
Add the nexthdr definitions for IPv6 which are used by wireless
drivers and were previously placed in an 80211 header file by
accident.
Obtained from: bz_iwlwifi
Sponsored by: The FreeBSD Foundation
Reviewed by: hselasky
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D31321
Add the two new functions needed by rtw88 to register the driver and
handle the module bits as well as a version of pci_alloc_irq_vectors()
for what is needed.
Reviewed by: hselasky
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D30981
In the futex_atomic_op() the encoded_op is a user-supplied parameter.
If the user specifies an incorrect value for this parameter paired with a valid
*uaddr parameter the caller will go into the endless loop. To prevent this check
futex_atomic_op() result and break the loop in case of ENOSYS.
MFC after: 2 weeks
For the caller is no need for access checking here, as the caller must take care
of EFAULT handling. Moreover, this check would be superfluous, since EFAULT is
extremily rare, and we prefer the fast path.
MFC after: 2 weeks
Initial patch from submitter was adapted by me to prevent unconditional
FUTEX_REQUEUE use.
PR: 255947
Submitted by: Philippe Michaud-Boudreault
Differential Revision: https://reviews.freebsd.org/D30332
Move flags and rtclock to the struct linux_futex_args. This will be used when
I split linux_futex() into separate futex op functions.
MFC after: 2 weeks
As the sv_shared_page_base now pointed out to the native sharedpage and
the process VA layout has changed as follows:
VDSOPAGE (2 * PAGE_SIZE)
SHAREDPAGE (PAGE_SIZE)
USRSTACK
fixup the vDSO name by calculating the start of page relative to the
native sharedpage.
Differential revision: https://reviews.freebsd.org/D30903
MFC after: 2 weeks
The vDSO (virtual dynamic shared object) is a small shared library that the
kernel maps R/O into the address space of all Linux processes on image
activation. The vDSO is a fully formed ELF image, shared by all processes
with the same ABI, has no process private data.
The primary purpose of the vDSO:
- non-executable stack, signal trampolines not copied to the stack;
- signal trampolines unwind, mandatory for the NPTL;
- to avoid contex-switch overhead frequently used system calls can be
implemented in the vDSO: for now gettimeofday, clock_gettime.
The first two have been implemented, so add the implementation of system
calls.
System calls implemenation based on a native timekeeping code with some
limitations:
- ifunc can't be used, as vDSO r/o mapped to the process VA and rtld
can't relocate symbols;
- reading HPET memory is not implemented for now (TODO).
In case on any error vDSO system calls fallback to the kernel system
calls. For unimplemented vDSO system calls added prototypes which call
corresponding kernel system call.
Tested by: trasz (arm64)
Differential revision: https://reviews.freebsd.org/D30900
MFC after: 2 weeks
This allows other threads to execute, typically during hardware waiting loops.
This also maches how the function works in Linux.
Reviewed by: kib
MFC after: 1 week
Sponsored by: NVIDIA Networking
These ABIs do not use umtx at all, so there is nothing to clean.
Cloudabi references to umtx keys do not require any cleanups anyway.
Requested by: dchagin
Reviewed by: dchagin, markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D30987
Use sysentvec hooks to only call umtx_thread_exit/umtx_exec, which handle
robust mutexes, for native FreeBSD ABI. Similarly, there is no sense
in calling sigfastblock_clear() for non-native ABIs.
Requested by: dchagin
Reviewed by: dchagin, markj (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D30987
as a thin wrapper around native version found in sys/seqc.h.
This replaces out-of-base GPLv2-licensed code used by drm-kmod.
Reviewed by: hselasky
Differential revision: https://reviews.freebsd.org/D31006
strscpy copies the src string, or as much of it as fits, into the dst
buffer. The dst buffer is always NUL terminated, unless it's zero-sized.
strscpy returns the number of characters copied (not including the
trailing NUL) or -E2BIG if len is 0 or src was truncated.
Currently drm-kmod replaces strscpy with strncpy that is not quite
correct as strncpy does not NUL-terminate truncated strings and returns
different values on exit.
Reviewed by: hselasky, imp, manu
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D31005
This allows to remove unimplemented attrs parameter which type differs
between Linux kernel versions and to compile both drm-kmod and ofed
callers unmodified.
Also convert it to 'unsigned long' type to match modern Linuxes.
Reviewed by: hselasky
Differential revision: https://reviews.freebsd.org/D30932
Linux docs explicitly state that this is not required [1]:
"Important note: The rcu_barrier() function is not, repeat, not,
obligated to wait for a grace period. It is instead only required to
wait for RCU callbacks that have already been posted. Therefore, if
there are no RCU callbacks posted anywhere in the system, rcu_barrier()
is within its rights to return immediately. Even if there are
callbacks posted, rcu_barrier() does not necessarily need to wait for
a grace period."
[1] https://www.kernel.org/doc/Documentation/RCU/Design/Requirements/Requirements.html
Reviewed by: emaste, hselasky, manu
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D30809
so this list-traversal primitive may safely run concurrently with the
_rcu list-mutation primitives such as list_add_rcu() as long as the
traversal is guarded by rcu_read_lock().
Do it by reusing the "list_for_each_entry_rcu" macro which does the same.
On Linux it implements some additional lockdep stuff which we skip.
Also move the macro to linux/rculist.h where it resides on Linux.
Reviewed by: hselasky
Differential revision: https://reviews.freebsd.org/D30795
as it is required by i915kms driver from Linux kernel v 5.5.
This is done with asynchronous freeing of requested memory areas from
taskqueue thread. As memory to be freed is reused to store linked list
entry, backing UMA zone item size is rounded up to pointer size.
While here, make struct linux_kmem_cache private to LKPI to reduce amount
of BSD headers included by linux/slab.h and switch RCU code to usage of
LKPI's linux_irq_work_tq taskqueue to avoid injection of current into
system-wide taskqueue_fast thread context.
Submitted by: nc (initial version for drm-kmod)
Reviewed by: manu, nc
Differential revision: https://reviews.freebsd.org/D30760
This makes prctl(2) support PR_SET_NO_NEW_PRIVS, by mapping it
to the native PROC_NO_NEW_PRIVS_CTL procctl(2).
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30973
This introduces a new, per-process flag, "NO_NEW_PRIVS", which
is inherited, preserved on exec, and cannot be cleared. The flag,
when set, makes subsequent execs ignore any SUID and SGID bits,
instead executing those binaries as if they not set.
The main purpose of the flag is implementation of Linux
PROC_SET_NO_NEW_PRIVS prctl(2), and possibly also unpriviledged
chroot.
Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30939
Implement dumping core for Linux binaries on amd64, for both
32- and 64-bit executables. Some bits are still missing.
This is based on a prototype by chuck@.
Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30019
To avoid duplication in the vmstat -m output rename the kmalloc type short
description to 'lkpikmalloc' as the Linux emulation layer historically names
its linux malloc type as 'linux'.
Reviewed by: hselasky, kib, emaste
Differential Revision: https://reviews.freebsd.org/D30928
MFC after: 2 weeks
This adds `sv_elf_core_osabi`, `sv_elf_core_abi_vendor`,
and `sv_elf_core_prepare_notes` fields to `struct sysentvec`,
and modifies imgact_elf.c to make use of them instead
of hardcoding FreeBSD-specific values. It also updates all
of the ABI definitions to preserve current behaviour.
This makes it possible to implement non-native ELF coredump
support without unnecessary code duplication. It will be used
for Linux coredumps.
Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30921
Change linuxkpi_request_firmware_nowait() to deferred firmware loading
scheduling a task. This changes behaviour in some cases that we
return from loading the driver before the driver is finished
initialising if the driver does not deal with it (wait).
This brings the behaviour one would expect from when this function is
called and I implemented it to see if it would help a specific case.
Sponsored by: The FreeBSD Foundation
MFC after: 12 days
Reviewed by: hselasky, imp (earlier version)
Differential Revision: https://reviews.freebsd.org/D30830
Re-add pci_free_irq_vectors() accidentally removed in
d4a4960c65 and now needed by drm-kmod v5.5.
Reported by: wulf
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
X-MFC with: d4a4960c65
Assuming we can't run on i486, i586 class cpu, retire linux_kplatform var
and use hardcoded 'machine' value in linux_newuname().
I have added linux_kplatform for consistency with linux_platform which is
placed in to vdso to avoid excess copyout it on stack for AT_PLATFORM at
exec time.
This is the first stage of Linuxulator's vdso revision.
Reviewed by: trasz, imp
Differential Revision: https://reviews.freebsd.org/D30774
MFC after: 2 weeks
For now the Linux emulation layer uses in kernel ppoll(2) without
conversion of user supplied fd 'events', and does not convert the
kernel supplied fd 'revents'.
At least POLLRDHUP is handled by FreeBSD differently than by
Linux. Seems that Linux silencly ignores POLLRDHUP on non socket fd's
unlike FreeBSD, which does more strictly check and fails.
Rework the Linux ppoll, using kern_poll and converting 'events'
and 'revents' values.
While here, move poll events defines to the MI part of code as they
mostly identical on all arches except arm.
Differential Revision: https://reviews.freebsd.org/D30716
MFC after: 2 weeks
Fix a last minute change from d4a4960c65
based on review feedback in where a function now gets called before
it is declared which did not fully get merged back to my commit branch.
Noticed by: CI, jkim
MFC after: 10 days
X-MFC with: d4a4960c65
Sponsored-by: The FreeBSD Foundation
Some code manually calls local_bh_disable() and spin_lock() but
then calls spin_unlock_bh() (or vice versa).
Our code then calls local_bh_disable() again from spin_lock()
which means we have the thread pin count increased twice and that
means we get out of synch and are still pinned when returning to
user space.
Avoid this by adding the explicit local_bh_{enable,disable}() to
the spin_[un]lock_bh() versions.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30711
In sg_pcopy_from_buffer() is an error in that skip can underflow
and lead to bogus page arithmetics which may lead to memory corruption
or more likely panics. Once we found a s/g page to copy into there
is nothing to skip anymore so simply set skip to 0.
Sponsored by: The FreeBSD Foundation
MFC after: 5 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30676
Restructure some code and add support for various "managed" versions
for PCI resource management.
This is beyond of what iwlwifi needs but some was found with other
wireless drivers and it mostly all goes together.
Add one FreeBSD sepcific feature returning the resource rather than
the handle to allow us to use bus_*() functions in drivers directly.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30558
Given we are manually setting up the "device" in PCI in some cases,
we need to initialise the list and lock for device devres here as well
as otherwise we will panic on the uninitialised lock.
Sponsored by: The FreeBSD Foundation
MFC after: 5 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30681
Move request_irq() to an internal function which serves request_irq()
and the newly added request_threaded_irq() and devm_request_threaded_irq().
Likewise factor out parts of free_irq() to also be used with
devm_free_irq(). Add the storage and call to a thread_handler in case
of IRQ_WAKE_THREAD.
This is needed for the iwlwifi driver.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30549
Add dummy functions for dealing with "HotPlug" events which we currently
do not support.
Add pci_dev_get(), pci_find_ext_capability() and pci_pme_capable().
The added pcie_find_root_port() is a bit special as we need to create
another linux pci device; for that make lkpinew_pci_dev() public
which is also helpful for other cases when we want to use the Linux
routines to check for device identifiers only and need a container
for the "bsddev" to use natively. This has proven to avoid basic
checking code for the sake of rewriting it to native field names
elsewhere. Given we cache the newly created "root" we also need to
make sure we clean it up.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30521
dmam_pool_create() is a "managed" version of dma_pool_create() which
will cleanup everything left when the device goes away using the
devres framework. For that add an internal cleanup function to be
called from devres release.
This is used by at least one wireless driver.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30520
Add two new (though untested) functions to linux/device.h which are
dealing with manually managing the device/driver and are used by
at least one wireless driver. We may have to re-fine them in the
future.
Move the devres declarations further up so they can be used earlier
in the file.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30519
While currently the ifp gets cast to a net_device and then returned
and consumers are expecting an ifp again, allow parallel usage now and
in the future by extending and also passing the ifp directly back in
the netdev_notifier_info. Add a function to return the ifp instead of
the net_device.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Suggested by: hselasky
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30522
Filter out the flags we do support; previously we would print
out the flag value verbatim.
Reviewed By: dchagin
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30693
In Linux, these are macros to locks in the kernel for scheduling purposes.
But as with other macros in this header, we aren't doing anything with them
so we are doing `do {} while (0)` for now.
This is needed by the drm-kmod 5.7 update.
Approved by: hselasky (src)
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D30710
This fixes a number of AppImages; tested with
scribus-1.5.6.1-linux-x86_64.AppImage.
Reported By: @probonopd
Reviewed By: asomers, emaste
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30606
Retire ksiginfo_to_lsiginfo function, use siginfo_to_lsiginfo instead.
Convert rt_sigtimedwait siginfo variables to well known names.
MFC after: 2 weeks
Add more raditap definitions based on "names" found in actual drivers
and based on documentation from radiotap.org (where avail).
Leave one specific "duplicate" in the LinuxKPI implementation but
otherwise manage it all in net80211.
Sponsored by: The FreeBSD Foundation
MFC after: 10 days
Reviewed by: hselasky, adrian, sam
Differential Revision: https://reviews.freebsd.org/D30641
Add HWEIGHT32() macro needed by iwlwifi and while here add the 8/16/64
variants likewise.
Sponsored by: The FreeBSD Foundation
MFC after: 12 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30501
Now that mlx4 and ofed either are operating on ifnet functions
directly or have a private copy of these macros, we can remove them
from linux/netdevice.h.
With this only the #define for net_device to ifnet is left.
Sponsored by: The FreeBSD Foundation
MFC after: 12 days
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D30478
This removes all unused bits from linux/netdevice.h and migrates two
inline functions into the mlx4 and ofed code respectively.
This gets the mlx4/ofed (struct ifnet) specific bits down to 7 lines
in netdevice.h.
Sponsored by: The FreeBSD Foundation
MFC after: 13 days
Reviewed by: hselasky, kib
Differential Revision: https://reviews.freebsd.org/D30461
The second 'linuxcommon' line was added by c66f5b079d
but Linuxulator's modules dependend on 'linux_common'.
To avoid such mistakes in the future rename moduledata name and module
name to 'linux_common' and retire 'linuxcommon' line.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D30409
MFC after: 2 weeks
Introduce net/addrconf.h with an implementation to
addrconf_addr_solict_mult() used by WiFi drivers.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D30416
