copies.
No current line disciplines have a dynamically changing hotchar, and
expecting to receive anything sensible during a change in ldisc is
insane so no locking of the hotchar field is necessary.
we have to revert to TTYDISC which we know will successfully open
rather than try the previous ldisc which might also fail to open.
Do not let ldisc implementations muck about with ->t_line, and remove
code which checks for reopens, it should never happen.
Move ldisc->l_hotchar to tty->t_hotchar and have ldisc implementation
initialize it in their open routines. Reset to zero when we enter
TTYDISC. ("no" should really be -1 since zero could be a valid
hotchar for certain old european mainframe protocols.)
older API to list attributes on a file (zero-length attribute name)
to function. extattr_list_*() are now the only available APIs to
use when listing attributes.
the socket buffer having its limits adjusted. sbreserve() now acquires
the lock before calling sbreserve_locked(). In soreserve(), acquire
socket buffer locks across read-modify-writes of socket buffer fields,
and calls into sbreserve/sbrelease; make sure to acquire in keeping
with the socket buffer lock order. In tcp_mss(), acquire the socket
buffer lock in the calling context so that we have atomic read-modify
-write on buffer sizes.
the SS_NBIO flag from the parent socket to the child socket during an
accept() operation.
The file descriptor O_NONBLOCK flag would have been propagated already
by the fflag assignment, and therefore would have been inconsistent
with the underlying socket's so_state member.
This makes accept() more closely adhere to the API contract we effectively
outline in the manual page. Note also that Linux continues to differ here;
O_NONBLOCK is not propagated. The other BSDs do propagate the flag, as
does Solaris. The Single UNIX Specification does not offer specific
advice on this issue.
PR: kern/45733
Requested by: Jayanth Vijayaraghavan
Reviewed by: rwatson
* Obtain/release schedlock around calls to calcru.
* Sort switch cases which do not cascade per style(9).
* Sort local variables per style(9).
* Remove "superfluous" whitespace.
* Cleanup handling of NULL uap->tp in clock_getres(). It would probably
be better to return EFAULT like clock_gettime() does by passing the
pointer to copyout(), but I presume it was written to not fail on
purpose in the original code. I'll defer to -standards on this one.
Reported by: bde
This is not really used by the process but it's confusing to some
status readers to see zombie processes the "runnin" threads.
Pointed out by: Don Lewis <truckman@FreeBSD.org>
where it is known to detect a problem but the problem is not very easy
to fix. The warning became very common recently after a call to calcru()
was added to fill_kinfo_thread().
Another (much older) cause of "negative times" (actually non-monotonic
times) was fixed in rev.1.237 of kern_exit.c.
Print separate messages for non-monotonic and negative times.
from exit1(). sched_exit() must be called unconditionally from exit1().
It was called almost unconditionally because the only exits on system
shutdown if at all.
(2) Removed the comment that presumed to know what sched_exit() does.
sched_exit() does different things for the ULE case. The call became
essential when it started doing load average stuff, but its caller
should not know that.
(3) Didn't fix bugs caused by bitrot in the condition. The condition was
last correct in rev.1.208 when it was in wait1(). There p was spelled
curthread->td_proc and was for the waiting parent; now p is for the
exiting child. The condition was to avoid lowering init's priority.
It should be in sched_exit() itself. Lowering of priorities is broken
in other ways in at least the 4BSD scheduler, and doing it for init
causes less noticeable problems than doing it for for shells.
Noticed by: julian (1)
- sowakeup() now asserts the socket buffer lock on entry. Move
the call to KNOTE higher in sowakeup() so that it is made with
the socket buffer lock held for consistency with other calls.
Release the socket buffer lock prior to calling into pgsigio(),
so_upcall(), or aio_swake(). Locking for this event management
will need revisiting in the future, but this model avoids lock
order reversals when upcalls into other subsystems result in
socket/socket buffer operations. Assert that the socket buffer
lock is not held at the end of the function.
- Wrapper macros for sowakeup(), sorwakeup() and sowwakeup(), now
have _locked versions which assert the socket buffer lock on
entry. If a wakeup is required by sb_notify(), invoke
sowakeup(); otherwise, unconditionally release the socket buffer
lock. This results in the socket buffer lock being released
whether a wakeup is required or not.
- Break out socantsendmore() into socantsendmore_locked() that
asserts the socket buffer lock. socantsendmore()
unconditionally locks the socket buffer before calling
socantsendmore_locked(). Note that both functions return with
the socket buffer unlocked as socantsendmore_locked() calls
sowwakeup_locked() which has the same properties. Assert that
the socket buffer is unlocked on return.
- Break out socantrcvmore() into socantrcvmore_locked() that
asserts the socket buffer lock. socantrcvmore() unconditionally
locks the socket buffer before calling socantrcvmore_locked().
Note that both functions return with the socket buffer unlocked
as socantrcvmore_locked() calls sorwakeup_locked() which has
similar properties. Assert that the socket buffer is unlocked
on return.
- Break out sbrelease() into a sbrelease_locked() that asserts the
socket buffer lock. sbrelease() unconditionally locks the
socket buffer before calling sbrelease_locked().
sbrelease_locked() now invokes sbflush_locked() instead of
sbflush().
- Assert the socket buffer lock in socket buffer sanity check
functions sblastrecordchk(), sblastmbufchk().
- Assert the socket buffer lock in SBLINKRECORD().
- Break out various sbappend() functions into sbappend_locked()
(and variations on that name) that assert the socket buffer
lock. The !_locked() variations unconditionally lock the socket
buffer before calling their _locked counterparts. Internally,
make sure to call _locked() support routines, etc, if already
holding the socket buffer lock.
- Break out sbinsertoob() into sbinsertoob_locked() that asserts
the socket buffer lock. sbinsertoob() unconditionally locks the
socket buffer before calling sbinsertoob_locked().
- Break out sbflush() into sbflush_locked() that asserts the
socket buffer lock. sbflush() unconditionally locks the socket
buffer before calling sbflush_locked(). Update panic strings
for new function names.
- Break out sbdrop() into sbdrop_locked() that asserts the socket
buffer lock. sbdrop() unconditionally locks the socket buffer
before calling sbdrop_locked().
- Break out sbdroprecord() into sbdroprecord_locked() that asserts
the socket buffer lock. sbdroprecord() unconditionally locks
the socket buffer before calling sbdroprecord_locked().
- sofree() now calls socantsendmore_locked() and re-acquires the
socket buffer lock on return. It also now calls
sbrelease_locked().
- sorflush() now calls socantrcvmore_locked() and re-acquires the
socket buffer lock on return. Clean up/mess up other behavior
in sorflush() relating to the temporary stack copy of the socket
buffer used with dom_dispose by more properly initializing the
temporary copy, and selectively bzeroing/copying more carefully
to prevent WITNESS from getting confused by improperly
initialized mutexes. Annotate why that's necessary, or at
least, needed.
- soisconnected() now calls sbdrop_locked() before unlocking the
socket buffer to avoid locking overhead.
Some parts of this change were:
Submitted by: sam
Sponsored by: FreeBSD Foundation
Obtained from: BSD/OS
socket lock over pulling so_options and so_linger out of the socket
structure in order to retrieve a consistent snapshot. This may be
overkill if user space doesn't require a consistent snapshot.
resolved by socket locking: in particular, that we test the connection
state at the socket layer without locking, request that the protocol
begin listening, and then set the listen state on the socket
non-atomically, resulting in a non-atomic cross-layer test-and-set.
to vm_map_find() that is less likely to be outside of addressable memory
for 32-bit processes: just past the end of the largest possible heap.
This is the same hint that mmap() uses.
ki_childutime, and ki_emul. Also uses the timevaladd() routine to
correct the calculation of ki_childtime. That will correct the value
returned when ki_childtime.tv_usec > 1,000,000.
This also implements a new KERN_PROC_GID option for kvm_getprocs().
(there will be a similar update to lib/libkvm/kvm_proc.c)
Submitted by: Cyrille Lefevre
lock state. Convert tsleep() into msleep() with socket buffer mutex
as argument. Hold socket buffer lock over sbunlock() to protect sleep
lock state.
Assert socket buffer lock in sbwait() to protect the socket buffer
wait state. Convert tsleep() into msleep() with socket buffer mutex
as argument.
Modify sofree(), sosend(), and soreceive() to acquire SOCKBUF_LOCK()
in order to call into these functions with the lock, as well as to
start protecting other socket buffer use in their implementation. Drop
the socket buffer mutexes around calls into the protocol layer, around
potentially blocking operations, for copying to/from user space, and
VM operations relating to zero-copy. Assert the socket buffer mutex
strategically after code sections or at the beginning of loops. In
some cases, modify return code to ensure locks are properly dropped.
Convert the potentially blocking allocation of storage for the remote
address in soreceive() into a non-blocking allocation; we may wish to
move the allocation earlier so that it can block prior to acquisition
of the socket buffer lock.
Drop some spl use.
NOTE: Some races exist in the current structuring of sosend() and
soreceive(). This commit only merges basic socket locking in this
code; follow-up commits will close additional races. As merged,
these changes are not sufficient to run without Giant safely.
Reviewed by: juli, tjr
output to permanently (not ephemerally) go to the console. It is also
sent to any other console specified by TIOCCONS as normal.
While I'm here, document the kern.log_console_output sysctl.
