For machines having cmpxcgh16b instruction, i.e. everything but very
early Athlons, provide lockless implementation of delayed
invalidation.
The implementation maintains lock-less single-linked list with the
trick from the T.L. Harris article about volatile mark of the elements
being removed. Double-CAS is used to atomically update both link and
generation. New thread starting DI appends itself to the end of the
queue, setting the generation to the generation of the last element
+1. On DI finish, thread donates its generation to the previous
element. The generation of the fake head of the list is the last
passed DI generation. Basically, the implementation is a queued
spinlock but without spinlock.
Many thanks both to Peter Holm and Mark Johnson for keeping with me
while I produced intermediate versions of the patch.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
MFC note: td_md.md_invl_gen should go to the end of struct thread
Differential revision: https://reviews.freebsd.org/D19630
Code walks the list of contested turnstiles to calculate the priority
to unlend.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Use roundup2() and rounddown2() instead of inlining them.
Get rid of the fd local variable, use literal -1 for the mmap argument.
Use MAP_FAILED as mmap(2) failure indicator.
After that, apply some style.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The previous calculations for displaying the time since last switch
easily overflowed, after less than 36 min for hz=1000. Now overflow
takes 2000 times longer (as long as ticks takes to wrap).
Reviewed by: cem, markj
Sponsored by: Dell EMC Isilon
Differential revision: https://reviews.freebsd.org/D20273
A static analyzer complained about a couple instances of checking a
variable against NULL after already having dereferenced it.
- dmar_gas_alloc_region: remove the tautological NULL checks
- dmar_release_resources / dmar_fini_fault_log: don't deref unit->regs
unless initialized.
And while here, fix an inverted initialization check in dmar_fini_qi.
Reviewed by: kib
Sponsored by: Dell EMC Isilon
Differential revision: https://reviews.freebsd.org/D20263
an unknown switch is passed outputting the command usage. This is
because the NDIS driver is uninitialized when usage help is printed.
To resolve this we initialize the driver prior to the possibility of
printing the usage help message.
Obtained from: The wpa_supplicant port
MFC after: 1 week
As of r347410 IPSec is no longer built into GENERIC. The ipsec.ko module must
be loaded before we can execute the IPSec tests.
Check this, and skip the tests if IPSec is not available.
These datasets will generally be canmount=noauto,mountpoint=none (e.g.
zroot/var) but have children that may need to be mounted. Instead of
skipping that segment for no good reason, descend.
Submitted by: Wes Maag
Reported by: Wes Maag
MFC after: 3 days
libc was picked as the destination location for these because of the syscalls
that use these files as the lowest level place they are referenced.
Approved by: will (mentor), rgrimes, manu
Differential Revision: https://reviews.freebsd.org/D16728
Check the new LINUXKPI_VERSION macro for backwards compatibility.
This patch is part of D19565
Reviewed by: hps
Approved by: imp (mentor), hps
MFC after: 1 week
Also, make ktime_get_raw call getnanouptime instead of getnanotime
to match (the correct) ktime_get_raw_ns.
This patch is part of D19565
Reviewed by: hps
Approved by: imp (mentor), hps
MFC after: 1 week
This is reqired to use the gpiofunc behaviour for configuring GPIO
pins at boot time.
Submitted by: <yamori813@yahoo.co.jp>
Differential Revision: https://reviews.freebsd.org/D20170
leap-seconds file from NIST at ftp://ftp.nist.gov/pub/time.
Future updates should use the NIST version of file, available
at ftp://ftp.nist.gov/pub/time/leap-seconds.list .
Requested by: ian@
Obtained from: ftp://ftp.nist.gov/pub/time/leap-seconds.3676924800
MFC after: 3 days
In mountd.c, the grouplist structures are linked into a single global
linked list headed by "grphead". The only use of this linked list is
to free all list elements when the exportlist elements are also all being
free'd at the time the exports are being reloaded.
This patch replaces this one global linked list head with a list head in
each exportlist structure, where the grouplist elements for that exported
file system are linked.
The only change is that now the grouplist elements are free'd with the
associated exportlist element as they are free'd instead of all grouplist
elements being free'd after the exportlist elements are free'd. This
change should have no effect in practice.
This is being done, since a future patch that will add a "-I" option for
incrementally updating the exports in the kernel needs to know which
grouplist elements are associated with each exported file system and
having them linked into a list headed by the exportlist element does that.
MFC after: 1 month
r333175 converted the global multicast lock to a sleepable sx lock,
so the lock order with respect to the (non-sleepable) inp lock changed.
To handle this, r333175 and r333505 added code to drop the inp lock,
but this opened races that could leave multicast group description
structures in an inconsistent state. This change fixes the problem by
simply acquiring the global lock sooner. Along the way, this fixes
some LORs and bogus error handling introduced in r333175, and commits
some related cleanup.
Reported by: syzbot+ba7c4943547e0604faca@syzkaller.appspotmail.com
Reported by: syzbot+1b803796ab94d11a46f9@syzkaller.appspotmail.com
Reviewed by: ae
MFC after: 3 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20070
of the 'flags' argument to mmap(2) with Linux strace(1).
Reviewed by: dchagin
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20223
r346670 added an sx to close a race between the ifioctl handler and
interface destruction. Unfortunately, it clears if_softc immediately after
the interface is closed, but before if_detach has been invoked.
Any time before detachment, an interface that's part of a bridge may still
receive traffic that's pushed through tunstart/tunstart_l2 and promptly
lead to a panic because if_softc is now NULL.
Fix it by deferring the clearing of if_softc until after the interface has
detached and thus been removed from the bridge. if_softc still gets cleared
in case another thread has already entered the ioctl handler before it's
replaced with ifdead_ioctl.
Reported by: markj
MFC after: 3 days
The upstream implementation of -z ifunc-noplt disallows its combination
with -z text. The option does not have much significance for kernel
builds, though.
Reviewed by: kib (previous version)
Discussed with: emaste
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20260
Microarchitectural buffers on some Intel processors utilizing
speculative execution may allow a local process to obtain a memory
disclosure. An attacker may be able to read secret data from the
kernel or from a process when executing untrusted code (for example,
in a web browser).
Reference: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00233.html
Security: CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091
Security: FreeBSD-SA-19:07.mds
Reviewed by: jhb
Tested by: emaste, lwhsu
Approved by: so (gtetlow)
We have a better, more comprehensive knob for this now:
kern.random.initial_seeding.bypass_before_seeding=1.
Requested by: delphij
Sponsored by: Dell EMC Isilon
file_loadraw():
check for file_alloc() and strdup() results.
we leak 'name'.
mod_load() does leak 'filename'.
mod_loadkld() does not need to check fp, file_discard() does check.
Release BPF_LOCK() before invoking if_output() and if_input().
Also enter epoch section before releasing lock, this should prevent
access to ifnet that may be freed on interface detach.
Reported by: markj
(1) We may have had sufficient entropy to consider Fortuna seeded, but the
random_fortuna_seeded() function would produce a false negative if
fs_counter was still zero. This condition could arise after
random_harvestq_prime() processed the /boot/entropy file and before any
read-type operation invoked "pre_read()." Fortuna's fs_counter variable is
only incremented (if certain conditions are met) by reseeding, which is
invoked by random_fortuna_pre_read().
is_random_seeded(9) was introduced in r346282, but the function was unused
prior to r346358, which introduced this regression. The regression broke
initial seeding of arc4random(9) and broke periodic reseeding[A], until something
other than arc4random(9) invoked read_random(9) or read_random_uio(9) directly.
(Such as userspace getrandom(2) or read(2) of /dev/random. By default,
/etc/rc.d/random does this during multiuser start-up.)
(2) The conditions under which Fortuna will reseed (including initial seeding)
are: (a) sufficient "entropy" (by sheer byte count; default 64) is collected
in the zeroth pool (of 32 pools), and (b) it has been at least 100ms since
the last reseed (to prevent trivial DoS; part of FS&K design). Prior to
this revision, initial seeding might have been prevented if the reseed
function was invoked during the first 100ms of boot.
This revision addresses both of these issues. If random_fortuna_seeded()
observes a zero fs_counter, it invokes random_fortuna_pre_read() and checks
again. This addresses the problem where entropy actually was sufficient,
but nothing had attempted a read -> pre_read yet.
The second change is to disable the 100ms reseed guard when Fortuna has
never been seeded yet (fs_lasttime == 0). The guard is intended to prevent
gratuitous subsequent reseeds, not initial seeding!
Machines running CURRENT between r346358 and this revision are encouraged to
refresh when possible. Keys generated by userspace with /dev/random or
getrandom(9) during this timeframe are safe, but any long-term session keys
generated by kernel arc4random consumers are potentially suspect.
[A]: Broken in the sense that is_random_seeded(9) false negatives would cause
arc4random(9) to (re-)seed with weak entropy (SHA256(cyclecount ||
FreeBSD_version)).
PR: 237869
Reported by: delphij, dim
Reviewed by: delphij
Approved by: secteam(delphij)
X-MFC-With: r346282, r346358 (if ever)
Security: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20239
of them listed in opt_global.h which is not generated while building
modules outside of a kernel and such modules never match real cofigured
kernel.
So, we should prevent our users from building obviously defective modules.
Therefore, remove the root cause of the building of modules outside of a
kernel - the possibility of building modules with DEBUG or KTR flags.
And remove all of DEBUG printfs as it is incomplete and in threaded
programms not informative, also a half of system call does not have DEBUG
printf. For debuging Linux programms we have dtrace, ktr and ktrace ability.
PR: 222861
Reviewed by: trasz
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20178
