attempting to change the BPF filter on a BPF descriptor at the same
time: retrieve the old filter pointer under the same locked region
as setting the new pointer.
MFC after: 3 days
(and panic). To try to finish making BPF safe, at the very least,
the BPF descriptor lock really needs to change into a reader/writer
lock that controls access to "settings," and a mutex that controls
access to the selinfo/knote/callout. Also, use of callout_drain()
instead of callout_stop() (which is really a much more widespread
issue).
BPFD_LOCK() when removing a descriptor from an interface descriptor
list. Hold both over the operation, and do a better job at
maintaining the invariant that you can't find partially connected
descriptors on an active interface descriptor list.
This appears to close a race that resulted in the kernel performing
a NULL pointer dereference when BPF sessions are detached during
heavy network activity on SMP systems.
RELENG_5 candidate.
to use queue(3) list macros rather than hand-crafted lists. While
here, move to doubly linked lists to eliminate iterating lists in
order to remove entries. This change simplifies and clarifies the
list logic in the BPF descriptor code as a first step towards revising
the locking strategy.
RELENG_5 candidate.
Reviewed by: fenner
a more complete subsystem, and removes the knowlege of how things are
implemented from the drivers. Include locking around filter ops, so a
module like aio will know when not to be unloaded if there are outstanding
knotes using it's filter ops.
Currently, it uses the MTX_DUPOK even though it is not always safe to
aquire duplicate locks. Witness currently doesn't support the ability
to discover if a dup lock is ok (in some cases).
Reviewed by: green, rwatson (both earlier versions)
before grabbing BPF locks to see if there are any entries in order to
avoid the cost of locking if there aren't any. Avoids a mutex lock/
unlock for each packet received if there are no BPF listeners.
The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()
Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
ifp->if_output() basedd on debug.mpsafenet. That way once bpfwrite()
can be called without Giant, it will acquire Giant (if desired) before
entering the network stack.
the need to synchronize access to the structure. I believe this
should fit into the stack under the necessary circumstances, but
if not we can either add synchronization or use a thread-local
malloc for the duration.
BPF. Grab the BPF descriptor lock before entering MAC since the MAC
Framework references BPF descriptor fields, including the BPF
descriptor label.
Submitted by: sam
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.
Free approx 86 major numbers with a mostly automatically generated patch.
A number of strategic drivers have been left behind by caution, and a few
because they still (ab)use their major number.
a new bpf_mtap2 routine that does the right thing for an mbuf
and a variable-length chunk of data that should be prepended.
o while we're sweeping the drivers, use u_int32_t uniformly when
when prepending the address family (several places were assuming
sizeof(int) was 4)
o return M_ASSERTVALID to BPF_MTAP* now that all stack-allocated
mbufs have been eliminated; this may better be moved to the bpf
routines
Reviewed by: arch@ and several others
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)
and set the link type for use by libpcap and tcpdump
o move mtx unlock in bpfdetach up; it doesn't need to be held so long
o change printf in bpf_detach to distinguish it from the same one in bpfsetdlt
Note there are locking issues here related to ioctl processing; they
have not been addressed here.
Submitted by: Guy Harris <guy@alum.mit.edu>
Obtained from: NetBSD (w/ locking modifications)
o introduce BPF_TAP and BPF_MTAP macros to hide implementation details and
ease code portability
o use m_getcl where appropriate
Reviewed by: many
Approved by: re
Obtained from: NetBSD (multiple link type support)
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
