An assertion was modified to use the found value, but it was not updated to
handle a race where blocked threads appear after the entrance to the func.
Move the assertion down to the area protected with sleepq lock where the
lock is read anyway. This does not affect coverage of the assertion and
is consistent with what rw locks are doing.
Reported by: Shawn Webb
The pair is of use only in debug or LOCKPROF kernels, but was passed (zeroed)
for many locks even in production kernels.
While here whack the tid argument from wlock hard and xlock hard.
There is no kbi change of any sort - "external" primitives still accept the
pair.
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Initially, only tag files that use BSD 4-Clause "Original" license.
RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133
Previously, symlinks in FreeBSD were artificially limited to PATH_MAX-2.
Add a short test case to verify the change.
Submitted by: Gaurav Gangalwar <ggangalwar AT isilon.com>
Reviewed by: kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12589
This shortens the lock hold time while not affecting corretness.
All the woken up threads end up competing can lose the race against
a completely unrelated thread getting the lock anyway.
clock_ts_to_ct has a KASSERT that the converted year fits into four
digits. By default (sysctl debug.allow_insane_settime is 0) the kernel
disallows a time too far in the future, using a value of 9999 366-day
years. However, clock_settime is epoch-relative and the assertion will
fail with a tv_sec corresponding to some 8030 years.
Avoid trying to be too clever, and just use a limit of 8000 365-day
years past the epoch.
Submitted by: Heqing Yan <scottieyan@gmail.com>
Reported by: Syzkaller (https://github.com/google/syzkaller)
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
kern.poweroff_on_panic which, when enabled, instructs a system to
power off on a panic instead of a reboot.
kern.powercyle_on_panic which, when enabled, instructs a system to
power cycle, if possible, on a panic instead of a reboot.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13042
The PT_DETACH case above the sendsig: label already looped over all
threads clearing flags in td_dbgflags. Reuse this loop to clear
TDB_SUSPEND and move the logic out of the sendsig: block.
Most of the conditionals in the 'sendsig:' block are now only different
for PT_ATTACH vs other continue requests. Pull the PT_ATTACH-specific
logic up into the PT_ATTACH case and simplify the 'sendsig:' block. This
also permits moving the unlock of proctree_lock above the sendsig: label
since PT_KILL doesn't hold the lock and and the other cases all fall
through to the label.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D13073
This fixes a panic when attaching to an already-stopped process after
r325028. While here, clean up a few other things in the control flow
of the 'sendsig' section:
- Only check for P_STOPPED_TRACE rather than either of P_STOPPED_SIG
or P_STOPPED_TRACE for most ptrace requests. The signal handling
code in kern_sig.c never sets just P_STOPPED_SIG for a traced
process, so if P_STOPPED_SIG is stopped, P_STOPPED_TRACE should be
set anyway. Remove a related debug printf. Assuming P_STOPPED_TRACE
permits simplifications in the 'sendsig:' block.
- Move the block to clear the pending thread state up into a new
block conditional on P_STOPPED_TRACE and handle delivering pending
signals to the reporting thread and clearing the reporting thread's
state in this block.
- Consolidate case to send a signal to the process in a single case
for PT_ATTACH. The only case that could have been in the else before
was a PT_ATTACH where P_STOPPED_SIG was not set, so both instances
of kern_psignal() collapse down to just PT_ATTACH.
Reported by: pho, mmel
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D12837
This introduces a facility to EVENTHANDLER(9) for explicitly defining a
reference to an event handler list. This is useful since previously all
invokers of events had to do a locked traversal of the global list of
event handler lists in order to find the appropriate event handler list.
By keeping a pointer to the appropriate list an invoker can avoid this
traversal completely. The pointer is initialized with SYSINIT(9) during
the eventhandler stage. Users registering interest in events do not need
to know if the event is backed by such a list, since the list is added
to the global list of lists. As with lists that are not pre-defined it
is safe to register for the events before the list has been created.
This converts the process_* and thread_* events to using the new
facility, as these are events whose locked traversals end up showing up
significantly in ports build workflows (and presumably other workflows
with many short lived threads/procs). It may be advantageous to convert
other events to using the new facility.
The el_flags field is now unused, but leave it be so that this revision
can be MFC'd.
Reviewed by: bdrewery, markj, mjg
Approved by: rstone (mentor)
In collaboration with: ian
MFC after: 4 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12814
similar to the kernel memory allocator.
This simplifies NUMA allocation because the domain will be known at wait
time and races between failure and sleeping are eliminated. This also
reduces boilerplate code and simplifies callers.
A wait primitive is supplied for uma zones for similar reasons. This
eliminates some non-specific VM_WAIT calls in favor of more explicit
sleeps that may be satisfied without new pages.
Reviewed by: alc, kib, markj
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Since the case of an empty chain was already covered, it si very likely
that the existing entry is matching. Skipping readlocking saves on lock
upgrade.
