kern_execve() locks text vnode exclusive to be able to set and clear
VV_TEXT flag. VV_TEXT is mutually exclusive with the v_writecount > 0
condition.
The change removes VV_TEXT, replacing it with the condition
v_writecount <= -1, and puts v_writecount under the vnode interlock.
Each text reference decrements v_writecount. To clear the text
reference when the segment is unmapped, it is recorded in the
vm_map_entry backed by the text file as MAP_ENTRY_VN_TEXT flag, and
v_writecount is incremented on the map entry removal
The operations like VOP_ADD_WRITECOUNT() and VOP_SET_TEXT() check that
v_writecount does not contradict the desired change. vn_writecheck()
is now racy and its use was eliminated everywhere except access.
Atomic check for writeability and increment of v_writecount is
performed by the VOP. vn_truncate() now increments v_writecount
around VOP_SETATTR() call, lack of which is arguably a bug on its own.
nullfs bypasses v_writecount to the lower vnode always, so nullfs
vnode has its own v_writecount correct, and lower vnode gets all
references, since object->handle is always lower vnode.
On the text vnode' vm object dealloc, the v_writecount value is reset
to zero, and deadfs vop_unset_text short-circuit the operation.
Reclamation of lowervp always reclaims all nullfs vnodes referencing
lowervp first, so no stray references are left.
Reviewed by: markj, trasz
Tested by: mjg, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D19923
NOSPLIT swap objects are not anonymous, they are used by tmpfs regular
files and POSIX shared memory. For such objects, collapse is not
permitted.
Reported by: mjg
Reviewed by: markj, trasz
Tested by: mjg, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19923
We unlock the vnode around malloc(M_WAITOK), to make it possible for
pagedaemon to flush vnode pages for us. Instead of doing it
unconditionally, first try M_NOWAIT allocation, which typically
succeed. Only on failure, unlock the vnode and retry with M_WAITOK.
Reviewed by: markj, trasz
Tested by: mjg, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19923
The bug and patch is reported against 11.2, but it is good idea to have
the check in place for all versions.
PR: 236585
Submitted by: john@feith.com
Reported by: john@feith.com
MFC after: 1 day
Right now ath_rate_sample has a fixed rate schedule, rather than the minstrel_ht
style "best, good, most reliable" triplet. So, if higher rates are tried then
it'll not fail back to a lower MCS rate in that transmission schedule.
This means that in low SNR situations it'll not easily drop to MCS0 unless enough
transmissions occur to allow rate control to eventually decide to drop; and if
it's TCP traffic it'll get slowed down because of packet loss.
It's worse for 2-stream and 3-stream rates; it doesn't ever fall back to lower
stream rates, and these higher stream rates required higher SNR to work.
So instead let's (for now?) have each of the 11n transmit rates use MCS0 as
the last attempt. ath_rate_sample will quickly see that rate succeeds more
and will move to it much quicker.
Testing:
* AR9344 (Wasp) - 2G STA mode
These are some fun issues I've found with my upstairs wifi link at such a ridiculous
low signal level (like, < 5dB.)
* Add per-station tx/rx rssi statistics, in potential preparation to use that
in the RX rate control.
* Call the rate control on each received frame to let it potentially use
it as a hint for what rates to potentially use. It's a no-op right now.
* Do ANI calibration during scan as well. The ath_newstate() call was disabling the
ANI timer and only re-enabling it during transitions to _RUN. This has the
unfortunate side-effect that if ANI deafened the NIC because of interference
and it disassociated, it wouldn't be reset and the scan would never hear beacons.
The ANI configuration is stored at least globally on some HALs and per-channel
on others. Because of this a NIC reset wouldn't help; the ANI parameters would
simply be programmed back in.
Now, I have a feeling I also need to do this during AUTH/ASSOC too and maybe,
if I'm feeling clever, I need to reset the ANI parameters on a given channel
during a transition through INIT or if the VAP is destroyed/re-created.
However for now this gets me out of the immediate weeds with connectivity
upstairs (and thus I /can/ commit); I'll keep chipping away at tidying this
stuff up in subsequent commits.
Tested:
* AR9344 (Wasp), 2G STA mode
IPI_STOP is used after panic or when ddb is entered manually. MONITOR/
MWAIT allows CPUs that support the feature to sleep in a low power way
instead of spinning. Something similar is already used at idle.
It is perhaps especially useful in oversubscribed VM environments, and is
safe to use even if the panic/ddb thread is not the BSP. (Except in the
presence of MWAIT errata, which are detected automatically on platforms with
known wakeup problems.)
It can be tuned/sysctled with "machdep.stop_mwait," which defaults to 0
(off). This commit also introduces the tunable
"machdep.mwait_cpustop_broken," which defaults to 0, unless the CPU has
known errata, but may be set to "1" in loader.conf to signal that mwait
wakeup is broken on CPUs FreeBSD does not yet know about.
Unfortunately, Bhyve doesn't yet support MONITOR extensions, so this doesn't
help bhyve hypervisors running FreeBSD guests.
Submitted by: Anton Rang <rang AT acm.org> (earlier version)
Reviewed by: kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20135
Rather than just accessing it via pointer cast.
No functional change intended.
Discussed with: kib (earlier version)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20135
The S/G list must be mapped AS-IS without any optimisations.
This also implies that sg_dma_len() must be equal to sg->length.
Many Linux drivers assume this and this fixes some DRM issues.
Put the BUS DMA map pointer into the scatter-gather list to
allow multiple mappings on the same physical memory address.
The FreeBSD version has been bumped to force recompilation of
external kernel modules.
Sponsored by: Mellanox Technologies
Summary:
A few ports fail to build due to missing pmap-related definitions, which are
specific per-pmap type. This tries to appease those ports, by merging all
pmaps together.
A future change will move the inline page directory out of the Book-E pmap,
to eliminate the last #ifdefs in pmap.h and complete the merge.
Reviewed By: luporl
Differential Revision: https://reviews.freebsd.org/D20119
Remove unnecessary `char*` casting for arguments passed to `cget*(3)`, and
deconst `_PATH_PRINTCAP` before passing it to `cget*` via the `printcapdb`
variable.
This unblocks ^/projects/runtime-coverage-v2 from building cleanly on
universe13a.freebsd.org. I suspect the issue was introduced through some
changes to `bsd.*.mk` inclusion on the branch, which I will continue to
investigate/isolate.
MFC after: 1 week
Tested with: clang 8 (arm64)
directory entries that is caused by uninitialized directory entry
padding written to the disk. It can be viewed by any user with read
access to that directory. Up to 3 bytes of kernel stack are disclosed
per file entry, depending on the the amount of padding the kernel
needs to pad out the entry to a 32 bit boundry. The offset in the
kernel stack that is disclosed is a function of the filename size.
Furthermore, if the user can create files in a directory, this 3
byte window can be expanded 3 bytes at a time to a 254 byte window
with 75% of the data in that window exposed. The additional exposure
is done by removing the entry, creating a new entry with a 4-byte
longer name, extracting 3 more bytes by reading the directory, and
repeating until a 252 byte name is created.
This exploit works in part because the area of the kernel stack
that is being disclosed is in an area that typically doesn't change
that often (perhaps a few times a second on a lightly loaded system),
and these file creates and unlinks themselves don't overwrite the
area of kernel stack being disclosed.
It appears that this bug originated with the creation of the Fast
File System in 4.1b-BSD (Circa 1982, more than 36 years ago!), and
is likely present in every Unix or Unix-like system that uses
UFS/FFS. Amazingly, nobody noticed until now.
This update also adds the -z flag to fsck_ffs to have it scrub
the leaked information in the name padding of existing directories.
It only needs to be run once on each UFS/FFS filesystem after a
patched kernel is installed and running.
Submitted by: David G. Lawrence <dg@dglawrence.com>
Reviewed by: kib
MFC after: 1 week
OVMF's flash variable storage is using add instructions when indexing
the variable store bootrom location.
Submitted by: D Scott Phillips <d.scott.phillips@intel.com>
Reviewed by: rgrimes
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19975
We're storing an EFI_HANDLE, not an pointer to a handle. Since
EFI_HANDLE is a void * anyway, this has little practical effect since
the conversion to / from void * and void ** is silent.
lock mac_ifnet_mtx, which protects labels on struct ifnet, unless at least
one policy is actively using labels on ifnets. This avoids a global mutex
acquire in certain fast paths -- most noticeably ifnet transmit. This was
previously invisible by default, as no MAC policies were loaded by default,
but recently became visible due to mac_ntpd being enabled by default.
gallatin@ reports a reduction in PPS overhead from 300% to 2.2% with this
change. We will want to explore further MAC Framework optimisation to
reduce overhead further, but this brings things more back into the world
of the sane.
MFC after: 3 days
This change creates an array of port maps indexed by numa domain
for lacp port selection. If we have lacp interfaces in more than
one domain, then we select the egress port by indexing into the
numa port maps and picking a port on the appropriate numa domain.
This is behavior is controlled by the new ifconfig use_numa flag
and net.link.lagg.use_numa sysctl/tunable (both modeled after the
existing use_flowid), which default to enabled.
Reviewed by: bz, hselasky, markj (and scottl, earlier version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20060
multiples of 8. Then the misaligned pixels at the end were not copied.
Clean up variable misuse related to this bug. The width in bytes was
first calculated correctly and used to do complicated reblocking
correctly, but it was stored in an unrelated scratch variable and later
recalculated with an off-by-1-error, so the last byte (times 4 planes)
in the intermediate copy was not copied.
This doubly-misaligned case is especially slow. Misalignment complicates
the reblocking, and each misaligment requires a read before write, and this
read is still not done from the shadow buffer.
move bits that are MI out into the headers in compat/linux.
For that remove bogus _packed attribute from struct l_sockaddr
and use MI types for struct members.
And continue to move into the linux_common module a code that is
intended for both Linuxulator modules (both instruction set - 32 & 64 bit)
or for external modules like linsysfs or linprocfs.
To avoid header pollution introduce new sys/compat/linux_common.h header.
Reviewed by: emaste
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20137
linear search can, so use it to avoid a linear search in isqrt.
Approved by: kib (mentor), markj (mentor)
Differential Revision: https://reviews.freebsd.org/D20102
The Windows virtio driver ignores the advertized seg_max field and
assumes the host can accept up to 67 segments in indirect descriptors,
triggering an assert in the bhyve process.
This brings back r282922 but with a couple of changes:
- It raises the block interface segment limit to 128 instead of 67.
- Linux's virtio driver assumes that the segment limit is no
larger than the ring size. To avoid breaking Linux guests,
raise the VirtIO ring size to 128, and cap the VirtIO segment
limit at ring size - 2 (effectively 126).
Reviewed by: rgrimes, Patrick Mooney <pmooney@pfmooney.com>
Obtained from: Joyent (Linux workaround)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18831
It's atypical, but not invalid, for a driver to pass no capabilities.
Submitted by: Gerald Aryeetey <aryeeteygerald_rogers.com>
Reviewed by: shurd
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20142
Use it wherever COMPAT_FREEBSD11 is currently specified, like r309749.
Reviewed by: imp, jhb, markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20120
Instead of pretending to successfully mount them while not actually
mounting anything, we'll now actually mount them *and* claim we mounted them
successfully.
Reported by: ler
MFC after: 3 days
The DTS for this board is already present in sys/gnu/dts/arm64/rockchip/
and just needs to be enabled.
Submitted by: alex@wied.io
Differential Revision: https://reviews.freebsd.org/D19823
