When sending SIGCHLD informing reaper that a zombie was reparented to
it, we might race with the situation where the previous parent still
not finished delivering SIGCHLD and having its p_ksi structure on the
signal queue. While on queue, the ksi should not be used for another
send.
Fix this by copying p_ksi into newly allocated ksi, which is directly
put onto reaper sigqueue. The later ensures that siginfo for reaper
SIGCHLD is always present, similar to guarantees for siginfo of child.
Reported by: bdrewery
Discussed with: jilles
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
For such segments, GNU bfd linker writes knowingly incorrect value
into the the file offset field of the program header entry, with the
motivation that file should not be mapped for creation of this segment
at all.
Relax checks for the ELF structure validity when on-disk segment
length is zero, and explicitely set mapping length to zero for such
segments to avoid validating rounding arithmetic.
PR: 217610
Reported by: Robert Clausecker <fuz@fuz.su>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
overly large allocation requests.
When ktrace-ing io, sys_kevent() allocates memory to copy the
requested changes and reported events. Allocations are sized by the
incoming syscall lengths arguments, which are user-controlled, and
might cause overflow in calculations or too large allocations.
Since io trace chunks are limited by ktr_geniosize, there is no sense
it even trying to satisfy unbounded allocations. Export ktr_geniosize
and clamp the buffers sizes in advance.
PR: 217435
Reported by: Tim Newsham <tim.newsham@nccgroup.trust>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
This function may be called recursively, when a module pulls its dependencies.
Under certain circumstances, e.g. quad chain of dependencies and presence
of dtrace we may run out of stack.
Suppose a traced process is stopped in ptracestop() due to receipt of a
SIGSTOP signal, and is awaiting orders from the tracing process on how
to handle the signal. Before sending any such orders, the tracing
process exits. This should kill the traced process. But suppose a second
thread handles the SIGKILL and proceeds to exit1(), calling
thread_single(). The first thread will now awaken and will have a chance
to check once more if it should go to sleep due to the SIGSTOP. It must
not sleep after P_SINGLE_EXIT has been set; this would prevent the
SIGKILL from taking effect, leaving a stopped orphan behind after the
tracing process dies.
Also add new tests for this condition.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9890
interpreter exactly matches the one requested by the activated image.
This change applies r295277, which did the same for note branding, to
the old brand selection, with the same reasoning of fixing compat32
interpreter substitution.
PR: 211837
Reported by: kenji@kens.fm
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
elf_load_section.
The values passed currently as vm_offset_t are phdr.p_offset, which
have the native Elf word size. Since elf_load_section interprets them
as the file offset, use vm object offset type.
Noted and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
stuck spinning at 100% cpu around sbcut_internal(). Inside
sbflush_internal(), sb_ccc reached to about 4GB and before passing it
to sbcut_internal(), we type-cast it from uint to int making it -ve.
The root cause of sockbuf growing this large is unknown. Correct fix
is also not clear but based on mailing list discussions, adding
KASSERTs to panic instead of looping endlessly.
Reviewed by: glebius
Sponsored by: Limelight Networks
header. This will help to correlate console server logs with dump files,
no matter how precise is clock on a console server appliance, and how
buggy the appliance is.
This KPI explicitely indicates the intent of creating the mapping at
the fixed address, and incorporates the map locking into the callee.
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
all the clocks that they provide.
Each clocks are exported under the node 'clock.<clkname>' and have the following
children nodes :
- frequency
- parent (The selected parent, if any)
- parents (The list of parents, if any)
- childrens (The list of childrens, if any)
- enable_cnt (The enabled counter)
This give us the possibility to examine clocks at runtime and make graph of
the clock flow.
Reviewed by: mmel
MFC after: 2 month
Differential Revision: https://reviews.freebsd.org/D9833
We may fail to reset the %CPU tracking window if a thread does not run
for over half of the ticks rollover period, resulting in a bogus %CPU
value for the thread until ticks fully rolls over. Handle this by comparing
the unsigned difference ticks - ts_ltick with SCHED_TICK_TARG instead.
Reviewed by: cem, jeff
MFC after: 1 week
Sponsored by: Dell EMC Isilon
Elf_map_insert() needs to create mapping at the known fixed address.
Usage of vm_map_find() assumes, on the other hand, that any suitable
address space range above or equal the specified hint, is acceptable.
Due to operating on the fresh or cleared address space, vm_map_find()
usually creates mapping starting exactly at hint.
Switch to vm_map_insert() use to clearly request fixed mapping from
the VM.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
vm_map_insert() failure, drop the vnode lock around the call to
vm_object_deallocate().
Since the deallocated object is the vm object of the vnode, we might
get the vnode lock recursion there. In fact, it is almost impossible
to make vm_map_insert() failing there on stock kernel.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Unclear how, but the locking routine for mutexes was using the *release*
barrier instead of acquire. This must have been either a copy-pasto or bad
completion.
Going through other uses of atomics shows no barriers in:
- upgrade routines (addressed in this patch)
- sections protected with turnstile locks - this should be fine as necessary
barriers are in the worst case provided by turnstile unlock
I would like to thank Mark Millard and andreast@ for reporting the problem and
testing previous patches before the issue got identified.
ps.
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Hardware provided by: IBM LTC
to stdout in the non-kernel case and to the console+log
in the kernel case. For the kernel case it hooks the
putbuf() machinery underneath printf(9) so that the buffer
is written completely atomically and without a copy into
another temporary buffer. This is useful for fixing
compound console/log messages that become broken and
interleaved when multiple threads are competing for the
console.
Reviewed by: ken, imp
Sponsored by: Netflix
Thread might create a condition for delayed SU cleanup, which creates
a reference to the mount point in td_su, but exit without returning
through userret(), e.g. when terminating due to single-threading or
process exit. In this case, td_su reference is not dropped and mount
point cannot be freed.
Handle the situation by clearing td_su also in the thread destructor
and in exit1(). softdep_ast_cleanup() has to receive the thread as
argument, since e.g. thread destructor is executed in different
context.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
On Core2 and older Intel CPUs, where TSC stops in C2, system does not
allow C2 entrance if timecounter hardware is TSC. This is done by
tc_windup() which tests for TC_FLAGS_C2STOP flag of the new
timecounter and increases cpu_disable_c2_sleep if flag is set. Right
now init_TSC_tc() only sets the flag if cpu_deepest_sleep >= 2, but
TSC is initialized too early for this variable to be set by
acpi_cpu.c.
There is no reason to require that ACPI reported C2 and deeper states
to set TC_FLAGS_C2STOP, so remove cpu_deepest_sleep test from
init_TSC_tc() condition. And since this is the only use of the
variable, remove it at all.
Reported and submitted by: Jia-Shiun Li <jiashiun@gmail.com>
Suggested by: jhb
MFC after: 2 weeks
This function allows the caller to specify the reference clock
and choose between absolute and relative mode. In relative mode,
the remaining time can be returned.
The API is similar to clock_nanosleep(3). Thanks to Ed Schouten
for that suggestion.
While I'm here, reduce the sleep time in the semaphore "child"
test to greatly reduce its runtime. Also add a reasonable timeout.
Reviewed by: ed (userland)
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9656
data structures.
vt_change_font() calls vtbuf_grow() to change some vt driver data
structures. It uses TF_MUTE to prevent the console from trying to use those
data structures while it changes them.
During the early stage of the boot process, the vt driver's tc_done routine
uses those data structures; however, it is currently called outside the
TF_MUTE check.
Move the tc_done routine inside the locked TF_MUTE check.
PR: 217282
Reviewed by: ed, ray
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D9709
then return EAGAIN. The current code just returns that if the LAST buf
failed.
Reviewed by: kib@, trasz@
Differential Revision: https://reviews.freebsd.org/D9677
Previously, the first lines of various generated files from system call
tables were generated in two sections. Some of the initialization was
done in BEGIN, and the rest was done when the first line was encountered.
The main reason for this split before r313564 was that most of the
initialization done in the second section depended on the $FreeBSD$ tag
extracted from the system call table. Now that the $FreeBSD$ tag is no
longer used, consolidate all of the file initialization in the BEGIN
section.
This change was tested by confirming that the content of generated files
did not change.
When a thread is stopped in ptracestop(), the ptrace(2) user may request
a signal be delivered upon resumption of the thread. Heretofore, those signals
were discarded unless ptracestop()'s caller was issignal(). Fix this by
modifying ptracestop() to queue up signals requested by the ptrace user that
will be delivered when possible. Take special care when the signal is SIGKILL
(usually generated from a PT_KILL request); no new stop events should be
triggered after a PT_KILL.
Add a number of tests for the new functionality. Several tests were authored
by jhb.
PR: 212607
Reviewed by: kib
Approved by: kib (mentor)
MFC after: 2 weeks
Sponsored by: Dell EMC
In collaboration with: jhb
Differential Revision: https://reviews.freebsd.org/D9260
