the tap driver, even with Giant over the cdev operation vector, due to
a non-atomic test-and-set of the si_drv1 field in the dev_t. This bug
exists with Giant under high memory pressure, as malloc() may sleep
in tapcreate(), but is less likely to occur. The resolution will
probably be to cover si_drv1 using the global tapmtx since no softc is
available, but I need to think about this problem more generally
across a range of drivers using si_drv1 in combination with SI_CHEAPCLONE
to defer expensive allocation to open().
Correct what appears to be a bug in the original if_tap implementation,
in which tapopen() will panic if a tap device instance is opened more
than once due to an incorrect assertion -- only triggered if INVARIANTS
is compiled in (i.e., when built into a kernel). Return EBUSY instead.
Expand mtx_lock() coverage using tp->tap_mtx to include tp->ether_addr.
(tap_pid, tap_flags). if_tap should now be entirely MPSAFE.
Committed from: Bamboo house by ocean in Taiwan
Tropical paradise provided by: Chia-liang Kao <clkao@clkao.org>
add tapmtx, which protects globale variables.
Notes:
- The EBUSY check in MOD_UNLOAD may be subject to a race. Moving the
event handler unregister inside the mutex grab may prevent that race.
- Locking of global variables safely is now possible because tapclones
is only modified when the module is loading or unloading, thanks to
phk's recent chang to clone_setup().
- softc locking to follow.
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.
Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
This commit adds a couple of functions for pseudodrivers to use for
implementing cloning in a manner we will be able to lock down (shortly).
Basically what happens is that pseudo drivers get a way to ask for
"give me the dev_t with this unit number" or alternatively "give
me a dev_t with the lowest guaranteed free unit number" (there is
unfortunately a lot of non-POLA in the exact numeric value of this
number, just live with it for now)
Managing the unit number space this way removes the need to use
rman(9) to do so in the drivers this greatly simplifies the code in
the drivers because even using rman(9) they still needed to manage
their dev_t's anyway.
I have taken the if_tun, if_tap, snp and nmdm drivers through the
mill, partly because they (ab)used makedev(), but mostly because
together they represent three different problems for device-cloning:
if_tun and snp is the plain case: just give me a device.
if_tap has two kinds of devices, with a flag for device type.
nmdm has paired devices (ala pty) can you can clone either of them.
thread being waken up. The thread waken up can run at a priority as
high as after tsleep().
- Replace selwakeup()s with selwakeuppri()s and pass appropriate
priorities.
- Add cv_broadcastpri() which raises the priority of the broadcast
threads. Used by selwakeuppri() if collision occurs.
Not objected in: -arch, -current
if_xname, if_dname, and if_dunit. if_xname is the name of the interface
and if_dname/unit are the driver name and instance.
This change paves the way for interface renaming and enhanced pseudo
device creation and configuration symantics.
Approved By: re (in principle)
Reviewed By: njl, imp
Tested On: i386, amd64, sparc64
Obtained From: NetBSD (if_xname)
branches:
Initialize struct cdevsw using C99 sparse initializtion and remove
all initializations to default values.
This patch is automatically generated and has been tested by compiling
LINT with all the fields in struct cdevsw in reverse order on alpha,
sparc64 and i386.
Approved by: re(scottl)
was used to control code which were conditional on DEVFS' precense
since this avoided the need for large-scale source pollution with
#include "opt_geom.h"
Now that we approach making DEVFS standard, replace these tests
with an #ifdef to facilitate mechanical removal once DEVFS becomes
non-optional.
No functional change by this commit.
o on input don't strip the Ethernet header from packets
o input packet handling is now done with if_input
o track changes to ether_ifattach/ether_ifdetach API
o track changes to bpf tapping
o call ether_ioctl for default handling of ioctl's
o use constants from net/ethernet.h where possible
Reviewed by: many
Approved by: re
dereference the struct sigio pointer without any locking. Change
fgetown() to take a reference to the pointer instead of a copy of the
pointer and call SIGIO_LOCK() before copying the pointer and
dereferencing it.
Reviewed by: rwatson
be done internally.
Ensure that no one can fsetown() to a dying process/pgrp. We need
to check the process for P_WEXIT to see if it's exiting. Process
groups are already safe because there is no such thing as a pgrp
zombie, therefore the proctree lock completely protects the pgrp
from having sigio structures associated with it after it runs
funsetownlst.
Add sigio lock to witness list under proctree and allproc, but over
proc and pgrp.
Seigo Tanimura helped with this.
Turn the sigio sx into a mutex.
Sigio lock is really only needed to protect interrupts from dereferencing
the sigio pointer in an object when the sigio itself is being destroyed.
In order to do this in the most unintrusive manner change pgsigio's
sigio * argument into a **, that way we can lock internally to the
function.
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.
Discussed on: smp@
not removing tabs before "__P((", and not outdenting continuation lines
to preserve non-KNF lining up of code with parentheses. Switch to KNF
formatting and/or rewrap the whole prototype in some cases.
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
which hides the 'hole' in the minor bits.
Introduce unit2minor() to do the reverse operation.
Fix some some make_dev() calls which didn't use UID_* or GID_* macros.
Kill the v_hashchain alias macro, it hides the real relationship.
Introduce experimental SI_CHEAPCLONE flag set it on cloned bpfs.
Add spl/splx to various sensitive spots
Change semantics of the vmnet version of the device to keep VMware happy
(don't junk state when the device is closed)
Submitted by: vsilyaev@mindspring.com
The tap driver is used to present a virtual Ethernet interface to the
system. Packets presented by the network stack to the interface are
made available to a character device in /dev. With tap and the bridge
code, you can make remote bridge configurations where both sides of
the bridge are separated by userland daemons.
This driver also has a special naming hack to allow it to serve a similar
purpose to the vmware port.
Submitted by: myevmenkin@att.com, vsilyaev@mindspring.com
