This should change nothing for kernel configurations at the standard
locations in the source tree. However, if KERNCONFDIR is used to
specify a custom location for a kernel configuration file (e.g., out of
tree), then both the custom location and the standard location, in this
order, will be used as include paths for config(8). This will allow the
kernel configuration to include files from both locations.
Reviewed by: bdrewery
MFC after: 16 days
Differential Revision: https://reviews.freebsd.org/D22057
The rationale is pretty much the same as in r353747.
There is no subsequent dependent store.
The store is to the regular (TSO) memory anyway.
MFC after: 23 days
After removing wmb(), vm_set_rendezvous_func() became super trivial, so
there was no point in keeping it.
The wmb (sfence on amd64, lock nop on i386) was not needed. This can be
explained from several points of view.
First, wmb() is used for store-store ordering (although, the primitive
is undocumented). There was no obvious subsequent store that needed the
barrier.
Second, x86 has a memory model with strong ordering including total
store order. An explicit store barrier may be needed only when working
with special memory (device, special caching mode) or using special
instructions (non-temporal stores). That was not the case for this
code.
Third, I believe that there is a misconception that sfence "flushes" the
store buffer in a sense that it speeds up the propagation of stores from
the store buffer to the global visibility. I think that such
propagation always happens as fast as possible. sfence only makes
subsequent stores wait for that propagation to complete. So, sfence is
only useful for ordering of stores and only in the situations described
above.
Reviewed by: jhb
MFC after: 23 days
Differential Revision: https://reviews.freebsd.org/D21978
This patch is part of an effort to make bhyve networking (in particular TCP)
faster. The key strategy to enhance TCP throughput is to let the whole packet
datapath work with TSO/LRO packets (up to 64KB each), so that the per-packet
overhead is amortized over a large number of bytes.
This capability is supported in the guest by means of the vtnet(4) driver,
which is able to handle TSO/LRO packets leveraging the virtio-net header
(see struct virtio_net_hdr and struct virtio_net_hdr_mrg_rxbuf).
A bhyve VM exchanges packets with the host through a network backend,
which can be vale(4) or if_tap(4).
While vale(4) supports TSO/LRO packets, if_tap(4) does not.
This patch extends if_tap(4) with the ability to understand the virtio-net
header, so that a tapX interface can process TSO/LRO packets.
A couple of ioctl commands have been added to configure and probe the
virtio-net header. Once the virtio-net header is set, the tapX interface
acquires all the IFCAP capabilities necessary for TSO/LRO.
Reviewed by: kevans
Differential Revision: https://reviews.freebsd.org/D21263
They're formatted into the device name like unit numbers, anyway; store the
number in mda_unit => si_drv0 like dev2unit() expects.
No functional change intended.
Sponsored by: Dell EMC Isilon
rename the WITH_LOADER_VERIEXEC_PASS_MANFIEST description to its correct
name. Also correct a bunch of spelling errors in that description.
MFC after: 3 days
In low memory conditions a significant number of pages may end up stuck
in the caches, and currently these caches cannot be reaped, leading to
spurious memory allocation failures and OOM kills. So:
- Take into account the fact that we may cache up to two full buckets
of pages per CPU, not just one.
- Increase the amount of RAM required per CPU to enable the caches.
This is a temporary measure until the page cache management policy is
improved.
PR: 241048
Reported and tested by: Kevin Oberman <rkoberman@gmail.com>
Reviewed by: alc, kib
Discussed with: jeff
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22040
The softdep lock names were unusually long and tended to stick out in
lock profiling reports. Abbreviate them and make them consistent with
our conventional style for lock names.
Reviewed by: mckusick
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22042
- We load the kernel at 0x200000. Memory below that address need not
be executable, so do not map it as such.
- Remove references to .ldata and related sections in the kernel linker
script. They come from ld.bfd's default linker script, but are not
used, and we now use ld.lld to link the amd64 kernel. lld does not
contain a default linker script.
- Pad the .bss to a 2MB as we do between .text and .data. This
forces the loader to load additional files starting in the following
2MB page, preserving the use of superpage mappings for kernel data.
- Map memory above the kernel image with NX. The kernel linker now
upgrades protections as needed, and other preloaded file types
(e.g., entropy, microcode) need not be mapped with execute permissions
in the first place.
Reviewed by: kib
MFC after: 1 month
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21859
With an upcoming change the amd64 kernel will map preloaded files RW
instead of RWX, so the kernel linker must adjust protections
appropriately using pmap_change_prot().
Reviewed by: kib
MFC after: 1 month
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21860
Use the section flags to derive mapping protections. When multiple
sections overlap within a page, the union of their protections must be
applied. With r353701 the .text and .rodata sections are padded to
ensure that this does not happen on amd64.
Reviewed by: kib
MFC after: 1 month
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21896
The change is for the example in textdump.4 and the default ddb.conf.
First of all, doadump now requires an argument and it won't do a
textdump if the argument is not 'true'.
And 'textdump dump' is more idiomatic anyway.
For what it's worth, ddb 'dump' command seems to always request a vmcore
dump even if a textdump was requested earlier, e.g., by 'textdump set'.
Finally, ddb 'call' command is not documented.
MFC after: 2 weeks
Move futex_mtx to linux_common.ko for amd64 and aarch64 along
with respective list/mutex init/destroy.
PR: 240989
Reported by: Alex S <iwtcex@gmail.com>
Move futex_list definition to linux.c which is included once
in linux.ko (i386) and in linux_common.ko (amd64 and aarch64)
allowing 32/64 bit linux programs to access the same futexes
in the latter case.
PR: 240989
Reviewed by: dchagin
Differential Revision: https://reviews.freebsd.org/D22073
when variance is small relative to data points.
Now [0, 1, 2] shows same standard deviation as [10000000000000, ...1, ...2]
Also: Various nitpickery from my own tree.
icmp_reflect(), called through icmp_error() requires us to be in NET_EPOCH.
Failure to hold it leads to the following panic (with INVARIANTS):
panic: Assertion in_epoch(net_epoch_preempt) failed at /usr/src/sys/netinet/ip_icmp.c:742
cpuid = 2
time = 1571233273
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00e0977920
vpanic() at vpanic+0x17e/frame 0xfffffe00e0977980
panic() at panic+0x43/frame 0xfffffe00e09779e0
icmp_reflect() at icmp_reflect+0x625/frame 0xfffffe00e0977aa0
icmp_error() at icmp_error+0x720/frame 0xfffffe00e0977b10
pf_intr() at pf_intr+0xd5/frame 0xfffffe00e0977b50
ithread_loop() at ithread_loop+0x1c6/frame 0xfffffe00e0977bb0
fork_exit() at fork_exit+0x80/frame 0xfffffe00e0977bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00e0977bf0
Note that we now enter NET_EPOCH twice if we enter ip_output() from pf_intr(),
but ip_output() will soon be converted to a function that requires epoch, so
entering NET_EPOCH directly from pf_intr() makes more sense.
Discussed with: glebius@
The sentinel value for "use the rest of the region," -1, isn't zero modulo
PAGE_SIZE. Relax the check to permit the intended special value.
X-MFC-With: r353110
Sponsored by: Dell EMC Isilon
Rather than a few scattered places in the tree. Organize flag names in a
contiguous region of specialreg.h.
While here, delete deprecated PCOMMIT from leaf 7.
No functional change.
When the underlying debugport transport is reliable, GDB's additional
checksums and acknowledgements are redundant. NoAckMode eliminates the
the acks and allows us to skip checking RX checksums. The GDB packet
framing does not change, so unfortunately (valid) checksums are still
included as message trailers.
The gdb(4) stub in FreeBSD advertises support for the feature in response to
the client's 'qSupported' request IFF the current debugport has the
gdb_dbfeatures flag GDB_DBGP_FEAT_RELIABLE set. Currently, only netgdb(4)
supports this feature.
If the remote GDB client supports the feature and does not have it disabled
via a GDB configuration knob, it may instruct our gdb(4) stub to enter
NoAckMode. Unless and until it issues that command, we must continue to
transmit acks as usual (and for now, we continue to wait until we receive
them as well, even if we know the debugport is on a reliable transport).
In the kernel sources, the sense of the flag representing the state of the
feature is reversed from that of the GDB command. (I.e., it is
'gdb_ackmode', not 'gdb_noackmode.') This is to avoid confusing double-
negative conditions.
For reference, see:
* https://sourceware.org/gdb/onlinedocs/gdb/Packet-Acknowledgment.html
* https://sourceware.org/gdb/onlinedocs/gdb/General-Query-Packets.html#QStartNoAckMode
Reviewed by: jhb, markj (both earlier version)
Differential Revision: https://reviews.freebsd.org/D21761
Use it to pad the text and read-only data sections to a 4KB boundary.
This will be used to enforce strict memory protections for some
sections of loadable kernel modules.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21970
NetGDB(4) is a component of a system using a panic-time network stack to
remotely debug crashed FreeBSD kernels over the network, instead of
traditional serial interfaces.
There are three pieces in the complete NetGDB system.
First, a dedicated proxy server must be running to accept connections from
both NetGDB and gdb(1), and pass bidirectional traffic between the two
protocols.
Second, the NetGDB client is activated much like ordinary 'gdb' and
similarly to 'netdump' in ddb(4) after a panic. Like other debugnet(4)
clients (netdump(4)), the network interface on the route to the proxy server
must be online and support debugnet(4).
Finally, the remote (k)gdb(1) uses 'target remote <proxy>:<port>' (like any
other TCP remote) to connect to the proxy server.
The NetGDB v1 protocol speaks the literal GDB remote serial protocol, and
uses a 1:1 relationship between GDB packets and sequences of debugnet
packets (fragmented by MTU). There is no encryption utilized to keep
debugging sessions private, so this is only appropriate for local
segments or trusted networks.
Submitted by: John Reimer <john.reimer AT emc.com> (earlier version)
Discussed some with: emaste, markj
Relnotes: sure
Differential Revision: https://reviews.freebsd.org/D21568
- Remove a redundant assignment of ef->address.
- Don't return a Mach error number to the caller if vm_map_find() fails.
- Use ptoa() and fix style.
MFC after: 2 weeks
Sponsored by: Netflix
At least one small update to the out-of-tree DRM drivers is required
now that cdev_pager_free_page() expects an xbusy page.
Discussed with: jeff, zeising
PATH_BOOTABLE_TOKEN can be set to a non-standard
path that identifies a device as bootable.
Reviewed by: kevans, bcran
Differential Revision: https://reviews.freebsd.org/D22062
It remains unattached to any client protocol. Netdump is unaffected
(remaining half-duplex). The intended consumer is NetGDB.
Submitted by: John Reimer <john.reimer AT emc.com> (earlier version)
Discussed with: markj
Differential Revision: https://reviews.freebsd.org/D21541
Loosen requirements for connecting to debugnet-type servers. Only require a
destination address; the rest can theoretically be inferred from the routing
table.
Relax corresponding constraints in netdump(4) and move ifp validation to
debugnet connection time.
Submitted by: John Reimer <john.reimer AT emc.com> (earlier version)
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D21482
Follow-up to incomplete pedantic change in r353691 by actually fixing the
default implementation to match the interface type. Mea culpa.
X-MFC-With: r353691, r339754
Add a 'X -s <server> -c <client> [-g <gateway>] -i <interface>' subroutine
to the generic debugnet code. The imagined use is both netdump, shown here,
and NetGDB (vaporware). It uses the ddb(4) lexer, with some new extensions,
to parse out IPv4 addresses.
'Netdump' uses the generic debugnet routine to load a configuration and
start a dump, without any netdump configuration prior to panic.
Loosely derived from work by: John Reimer <john.reimer AT emc.com>
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D21460
After r339754, the additional interface parameter was accidentally left out
of the default acpi_generic_id_probe implementation. Apparently this does
not cause any real problems, so this fix is mostly stylistic.
No functional change intended.
X-MFC-With: r339754
This allows ddb(4) commands to construct a static dumperinfo during
panic/debug and invoke doadump(false) using the provided dumper
configuration (always inserted first in the list).
The intended usecase is a ddb(4)-time netdump(4) command.
Reviewed by: markj (earlier version)
Differential Revision: https://reviews.freebsd.org/D21448
The in-tree netdump code has always ignored non-directed ARP requests, and
that seems to work most of the time for netdump.
In my work and testing on NetGDB, it seems like sometimes the remote FreeBSD
conversant (the non-panic system) will send broadcast-destination ARP
requests to the debugnet kernel; without this change, those are dropped and
the remote will see EHOSTDOWN "Host is down" errors from the userspace
interface of the network stack.
Discussed with: markj
Similar to INET checksums, lazily validate UDP checksums when the driver has
already performed the check for us. Like debugnet(4) INET checksums,
validation in software is left as future work.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D21745
Debugnet is a simplistic and specialized panic- or debug-time reliable
datagram transport. It can drive a single connection at a time and is
currently unidirectional (debug/panic machine transmit to remote server
only).
It is mostly a verbatim code lift from netdump(4). Netdump(4) remains
the only consumer (until the rest of this patch series lands).
The INET-specific logic has been extracted somewhat more thoroughly than
previously in netdump(4), into debugnet_inet.c. UDP-layer logic and up, as
much as possible as is protocol-independent, remains in debugnet.c. The
separation is not perfect and future improvement is welcome. Supporting
INET6 is a long-term goal.
Much of the diff is "gratuitous" renaming from 'netdump_' or 'nd_' to
'debugnet_' or 'dn_' -- sorry. I thought keeping the netdump name on the
generic module would be more confusing than the refactoring.
The only functional change here is the mbuf allocation / tracking. Instead
of initiating solely on netdump-configured interface(s) at dumpon(8)
configuration time, we watch for any debugnet-enabled NIC for link
activation and query it for mbuf parameters at that time. If they exceed
the existing high-water mark allocation, we re-allocate and track the new
high-water mark. Otherwise, we leave the pre-panic mbuf allocation alone.
In a future patch in this series, this will allow initiating netdump from
panic ddb(4) without pre-panic configuration.
No other functional change intended.
Reviewed by: markj (earlier version)
Some discussion with: emaste, jhb
Objection from: marius
Differential Revision: https://reviews.freebsd.org/D21421
