In addition to reducing lines of code, this also ensures that the full
allocation is always zeroed avoiding possible bugs with incorrect
lengths passed to explicit_bzero().
Suggested by: cem
Reviewed by: cem, delphij
Approved by: csprng (cem)
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D25435
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
Thanks to cem@ for discussing the issue which resulted in this patch.
Reviewed by: cem@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D22089
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
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
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
nd_buf is used to buffer headers (for both the kernel dump itself and
for EKCD) before the final call to netdump_dumper(), which flushes
residual data in nd_buf. As a result, a small portion of the residual
data would be corrupted. This manifests when kernel dump compression
is enabled since both zstd and zlib detect the corruption during
decompression.
Reviewed by: cem
Differential Revision: https://reviews.freebsd.org/D21294
netdump waits for acknowledgement from the server for each write. When
dumping page table pages, we perform many small writes, limiting
throughput. Use the netdump client's buffer to buffer small contiguous
writes before calling netdump_send() to flush the MAXDUMPPGS-sized
buffer. This results in a significant reduction in the time taken to
complete a netdump.
Submitted by: Sam Gwydir <sam@samgwydir.com>
Reviewed by: cem
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20317
These are obviously missing from the .c files, but don't show up in any
tinderbox configuration (due to latent header pollution of some kind). It
seems some configurations don't have this pollution, and the includes are
obviously missing, so go ahead and add them.
Reported by: Peter Jeremy <peter AT rulingia.com>
X-MFC-With: r347984
Boot-time netdump configuration is much more useful if one can configure the
client and gateway addresses. Fix trivial typo.
(Long-standing bug, I believe it dates to the original netdump commit.)
Spotted by: one of vangyzen@ or markj@
Sponsored by: Dell EMC Isilon
Prior to this revision, struct diocskerneldump_arg (and struct netdump_conf
with embedded diocskerneldump_arg before r347192), were copied in their
entirety to the global 'nd_conf' variable. Also prior to this revision,
de-configuring netdump would *not* remove the the key material from global
nd_conf.
As part of Encrypted Kernel Crash Dumps (EKCD), which was developed
contemporaneously with netdump but happened to land first, the
diocskerneldump_arg structure will contain sensitive key material
(kda_key[]) when encrypted dumps are configured.
Netdump doesn't have any use for the key data -- encryption is handled in
the core dumper code -- so in this revision, we no longer store it.
Unfortunately, I think this leak dates to the initial import of netdump in
r333283; so it's present in FreeBSD 12.0.
Fortunately, the impact *seems* relatively minor. Any new *netdump*
configuration would overwrite the key material; for active encrypted netdump
configurations, the key data stored was just a duplicate of the key material
already in the core dumper code; and no user interface (other than
/dev/kmem) actually exposed the leaked material to userspace.
Reviewed by: markj, rpokala (earlier commit message)
MFC after: 2 weeks
Security: yes (minor)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20233
Allow users to specify multiple dump configurations in a prioritized list.
This enables fallback to secondary device(s) if primary dump fails. E.g.,
one might configure a preference for netdump, but fallback to disk dump as a
second choice if netdump is unavailable.
This change does not list-ify netdump configuration, which is tracked
separately from ordinary disk dumps internally; only one netdump
configuration can be made at a time, for now. It also does not implement
IPv6 netdump.
savecore(8) is already capable of scanning and iterating multiple devices
from /etc/fstab or passed on the command line.
This change doesn't update the rc or loader variables 'dumpdev' in any way;
it can still be set to configure a single dump device, and rc.d/savecore
still uses it as a single device. Only dumpon(8) is updated to be able to
configure the more complicated configurations for now.
As part of revving the ABI, unify netdump and disk dump configuration ioctl
/ structure, and leave room for ipv6 netdump as a future possibility.
Backwards-compatibility ioctls are added to smooth ABI transition,
especially for developers who may not keep kernel and userspace perfectly
synced.
Reviewed by: markj, scottl (earlier version)
Relnotes: maybe
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D19996
The logic was present for the 11 version of the DIOCSKERNELDUMP ioctl, but
had not been updated for the 12 ABI.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D19980
There are a few places that use hand crafted versions of the macros
from sys/netinet/in.h making it difficult to actually alter the
values in use by these macros. Correct that by replacing handcrafted
code with proper macro usage.
Reviewed by: karels, kristof
Approved by: bde (mentor)
MFC after: 3 weeks
Sponsored by: John Gilmore
Differential Revision: https://reviews.freebsd.org/D19317
- Remove macros that covertly create epoch_tracker on thread stack. Such
macros a quite unsafe, e.g. will produce a buggy code if same macro is
used in embedded scopes. Explicitly declare epoch_tracker always.
- Unmask interface list IFNET_RLOCK_NOSLEEP(), interface address list
IF_ADDR_RLOCK() and interface AF specific data IF_AFDATA_RLOCK() read
locking macros to what they actually are - the net_epoch.
Keeping them as is is very misleading. They all are named FOO_RLOCK(),
while they no longer have lock semantics. Now they allow recursion and
what's more important they now no longer guarantee protection against
their companion WLOCK macros.
Note: INP_HASH_RLOCK() has same problems, but not touched by this commit.
This is non functional mechanical change. The only functionally changed
functions are ni6_addrs() and ni6_store_addrs(), where we no longer enter
epoch recursively.
Discussed with: jtl, gallatin
Fields owned by the generic code were being left uninitialized,
causing problems in clear_dumper() if an error occurred.
Coverity CID: 1391200
X-MFC with: r333283
We need to set the current vnet before iterating over the global
interface list. Because the dump device may only be set from the host,
only proceed with configuration if the thread belongs to the default
vnet. [1]
Also fix a resource leak that occurs if the priv_check() in set_dumper()
fails.
Reported by: mmacy, sbruno [1]
Reviewed by: sbruno
X-MFC with: r333283
Differential Revision: https://reviews.freebsd.org/D15449
This is a component of a system which lets the kernel dump core to
a remote host after a panic, rather than to a local storage device.
The server component is available in the ports tree. netdump is
particularly useful on diskless systems.
The netdump(4) man page contains some details describing the protocol.
Support for configuring netdump will be added to dumpon(8) in a future
commit. To use netdump, the kernel must have been compiled with the
NETDUMP option.
The initial revision of netdump was written by Darrell Anderson and
was integrated into Sandvine's OS, from which this version was derived.
Reviewed by: bdrewery, cem (earlier versions), julian, sbruno
MFC after: 1 month
X-MFC note: use a spare field in struct ifnet
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D15253
