Use the nitems() macro instead of the expansion, a'la r298352. Also, fix the
location of this check to after initializing availmem_regions_sz, so that the
check isn't always against 0, thus always failing (nitems(phys_avail) is always
more than 0).
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
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
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
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
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
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
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
r345519 rewrote parts of how we build .dtb, but mistakenly dropped the
vendor dir for aarch64. Simply drop the :T for building ${DTB} in the
aarch64 case- it'll get applied at install-time as-needed, with :H:T for
determining the vendor dir.
Reported by: manu
Tested by: manu
Reviewed by: manu
MFC after: 3 days
That makes Linux lscpu(1) work.
Reviewed by: dchagin
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20131
It's possible for a Hypervisor Maintenance Interrupt (HMI) to occur while in
the pmap code, holding locks. This can cause WITNESS to panic due to lock
errors in calling pmap_kextract(). Since we don't yet handle the flags
returned by OPAL_HANDLE_HMI2, just stop using it, so that we don't call into
pmap_kextract().
Reported by: pkubaj
Some UEFI implementations trash this register and, as we use it as a
platform register, the kernel doesn't save it before calling into the UEFI
runtime services. As we have a copy in tpidr_el1 restore from there when
exiting the EFI environment.
PR: 237234, 237055
Reviewed by: manu
Tested On: Ampere eMAG
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Sponsored by: Ampere Computing (hardware)
Differential Revision: https://reviews.freebsd.org/D20127
vm_map_wire() increments entry->wire_count, after that it drops the
map lock both for faulting in the entry' pages, and for marking next
entry in the requested region as IN_TRANSITION. Only after all entries
are faulted in, MAP_ENTRY_USER_WIRE flag is set.
This makes it possible for vm_map_protect() to run while other entry'
MAP_ENTRY_IN_TRANSITION flag is handled, and vm_map_busy() lock does
not prevent it. In particular, if the call to vm_map_protect() adds
VM_PROT_WRITE to CoW entry, it would fail to call
vm_fault_copy_entry(). There are at least two consequences of the
race: the top object in the shadow chain is not populated with
writeable pages, and second, the entry eventually get contradictory
flags MAP_ENTRY_NEEDS_COPY | MAP_ENTRY_USER_WIRED with VM_PROT_WRITE
set.
Handle it by waiting for all MAP_ENTRY_IN_TRANSITION flags to go away
in vm_map_protect(), which does not drop map lock afterwards. Note
that vm_map_busy_wait() is left as is.
Reported and tested by: pho (previous version)
Reviewed by: Doug Moore <dougm@rice.edu>, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D20091
Make function macro wrappers for locking and unlocking to ease readability.
No functional change.
Discussed with: kib@, tychon@ and zeising@
Sponsored by: Mellanox Technologies
Unconditional writing to MAS7, which doesn't exist on the e500v1 core, in a
TLB miss handler has been in the code for several years now. Since this has
gone unnoticed for so long, it's easily concluded that e500v1 is not in use
with FreeBSD. Simplify the code path a bit, by unconditionally zeroing MAS7
instead of calling a subroutine to do it.
r18 is used to hold the old PCB flags, but cpu_throw doesn't populate r18
with PCB flags, since the old thread is gone. This can lead to panics on
cores that don't have the registers guarded by these flags.
