- 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
