Commit Graph

374 Commits

Author SHA1 Message Date
Mateusz Guzik
f743ea9638 Bump struct thread alignment to 32.
This gives additional bits to use in locking primitives which store
the lock thread pointer in the lock value.

Discussed with:	kib
2017-02-07 17:03:22 +00:00
Bryan Drewery
28323add09 Fix improper use of "its".
Sponsored by:	Dell EMC Isilon
2016-11-08 23:59:41 +00:00
Kevin Lo
61f481fb7e Remove register keyword.
Reviewed by:	kib
2016-10-20 01:21:10 +00:00
Kevin Lo
7c68685366 Remove a sentence about putting initialization in init_proc.c or kern_proc.c
and useless comment.

Reviewed by:	kib
2016-10-20 01:19:37 +00:00
Nathan Whitehorn
8c636a11dc Remove assumptions in MI code that the BSP is CPU 0.
MFC after:	2 weeks
2016-07-11 21:25:28 +00:00
Konstantin Belousov
9e590ff04b When filt_proc() removes event from the knlist due to the process
exiting (NOTE_EXIT->knlist_remove_inevent()), two things happen:
- knote kn_knlist pointer is reset
- INFLUX knote is removed from the process knlist.
And, there are two consequences:
- KN_LIST_UNLOCK() on such knote is nop
- there is nothing which would block exit1() from processing past the
  knlist_destroy() (and knlist_destroy() resets knlist lock pointers).
Both consequences result either in leaked process lock, or
dereferencing NULL function pointers for locking.

Handle this by stopping embedding the process knlist into struct proc.
Instead, the knlist is allocated together with struct proc, but marked
as autodestroy on the zombie reap, by knlist_detach() function.  The
knlist is freed when last kevent is removed from the list, in
particular, at the zombie reap time if the list is empty.  As result,
the knlist_remove_inevent() is no longer needed and removed.

Other changes:

In filt_procattach(), clear NOTE_EXEC and NOTE_FORK desired events
from kn_sfflags for knote registered by kernel to only get NOTE_CHILD
notifications.  The flags leak resulted in excessive
NOTE_EXEC/NOTE_FORK reports.

Fix immediate note activation in filt_procattach().  Condition should
be either the immediate CHILD_NOTE activation, or immediate NOTE_EXIT
report for the exiting process.

In knote_fork(), do not perform racy check for KN_INFLUX before kq
lock is taken.  Besides being racy, it did not accounted for notes
just added by scan (KN_SCAN).

Some minor and incomplete style fixes.

Analyzed and tested by:	Eric Badger <eric@badgerio.us>
Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Approved by:	re (gjb)
Differential revision:	https://reviews.freebsd.org/D6859
2016-06-27 21:52:17 +00:00
Konstantin Belousov
5c2cf81845 Update comments for the MD functions managing contexts for new
threads, to make it less confusing and using modern kernel terms.

Rename the functions to reflect current use of the functions, instead
of the historic KSE conventions:
  cpu_set_fork_handler -> cpu_fork_kthread_handler (for kthreads)
  cpu_set_upcall -> cpu_copy_thread (for forks)
  cpu_set_upcall_kse -> cpu_set_upcall (for new threads creation)

Reviewed by:	jhb (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (hrs)
Differential revision:	https://reviews.freebsd.org/D6731
2016-06-16 12:05:44 +00:00
Konstantin Belousov
93ccd6bf87 Get rid of struct proc p_sched and struct thread td_sched pointers.
p_sched is unused.

The struct td_sched is always co-allocated with the struct thread,
except for the thread0.  Avoid useless indirection, instead calculate
td_sched location using simple pointer arithmetic in td_get_sched(9).
For thread0, which is statically allocated, create a structure to
emulate layout of the dynamic allocation.

Reviewed by:	jhb (previous version)
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D6711
2016-06-05 17:04:03 +00:00
Pedro F. Giffuni
d9c9c81c08 sys: use our roundup2/rounddown2() macros when param.h is available.
rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really
advantageous to do the replacement.

This tries to strike a balance between readability using the macros
and flexibility of having the expressions, so not everything is
converted.
2016-04-21 19:57:40 +00:00
Konstantin Belousov
db57c70a5b Rename P_KTHREAD struct proc p_flag to P_KPROC.
I left as is an apparent bug in ntoskrnl_var.h:AT_PASSIVE_LEVEL()
definition.

Suggested by:	jhb
Sponsored by:	The FreeBSD Foundation
2016-02-09 16:30:16 +00:00
John Baldwin
6270fa5f72 Mark proc0 as a kernel process via the P_KTHREAD flag.
All other kernel processes have this flag set and all threads in proc0
(including thread0) have the similar TDP_KTHREAD flag set.

PR:		204999
Submitted by:	Oliver Pinter @ HardenedBSD
Reviewed by:	kib
MFC after:	1 week
2016-02-08 23:06:27 +00:00
Mateusz Guzik
33fd9b9a2b fork: pass arguments to fork1 in a dedicated structure
Suggested by:	kib
2016-02-04 04:22:18 +00:00
Dmitry Chagin
038c720553 Implement vsyscall hack. Prior to 2.13 glibc uses vsyscall
instead of vdso. An upcoming linux_base-c6 needs it.

Differential Revision:  https://reviews.freebsd.org/D1090

Reviewed by:	kib, trasz
MFC after:	1 week
2016-01-09 20:18:53 +00:00
Konstantin Belousov
724f4b62b0 Remove sv_prepsyscall, sv_sigsize and sv_sigtbl members of the struct
sysent.

sv_prepsyscall is unused.

sv_sigsize and sv_sigtbl translate signal number from the FreeBSD
namespace into the ABI domain.  It is only utilized on i386 for iBCS2
binaries.  The issue with this approach is that signals for iBCS2 were
delivered with the FreeBSD signal frame layout, which does not follow
iBCS2.  The same note is true for any other potential user if
sv_sigtbl.  In other words, if ABI needs signal number translation, it
really needs custom sv_sendsig method instead.

Sponsored by:	The FreeBSD Foundation
2015-11-28 08:49:07 +00:00
Warner Losh
de830d432c Remove now obsolete comment.
MFC After: 2 days
2015-08-28 20:06:58 +00:00
Warner Losh
3f27281613 Per overwhelming sentiment in the code review, use FEATURE instead.
Differential Revision: https://reviews.freebsd.org/D3488
MFC After: 2 days
2015-08-28 19:53:19 +00:00
Warner Losh
135342777c When the kernel is compiled with INVARIANTS, export that as
debug.invariants.

Differential Revision: https://reviews.freebsd.org/D3488
MFC after: 3 days
2015-08-26 23:58:03 +00:00
Ed Schouten
367a13f905 Limit rights on process descriptors.
On CloudABI, the rights bits returned by cap_rights_get() match up with
the operations that you can actually perform on the file descriptor.

Limiting the rights is good, because it makes it easier to get uniform
behaviour across different operating systems. If process descriptors on
FreeBSD would suddenly gain support for any new file operation, this
wouldn't become exposed to CloudABI processes without first extending
the rights.

Extend fork1() to gain a 'struct filecaps' argument that allows you to
construct process descriptors with custom rights. Use this in
cloudabi_sys_proc_fork() to limit the rights to just fstat() and
pdwait().

Obtained from:	https://github.com/NuxiNL/freebsd
2015-07-31 10:21:58 +00:00
Mateusz Guzik
cd672ca60f Get rid of lim_update_thread and cred_update_thread.
Their primary use was in thread_cow_update to free up old resources.
Freeing had to be done with proc lock held and _cow_ funcs already knew
how to free old structs.
2015-07-16 14:30:11 +00:00
Adrian Chadd
6520495abc Add an initial NUMA affinity/policy configuration for threads and processes.
This is based on work done by jeff@ and jhb@, as well as the numa.diff
patch that has been circulating when someone asks for first-touch NUMA
on -10 or -11.

* Introduce a simple set of VM policy and iterator types.
* tie the policy types into the vm_phys path for now, mirroring how
  the initial first-touch allocation work was enabled.
* add syscalls to control changing thread and process defaults.
* add a global NUMA VM domain policy.
* implement a simple cascade policy order - if a thread policy exists, use it;
  if a process policy exists, use it; use the default policy.
* processes inherit policies from their parent processes, threads inherit
  policies from their parent threads.
* add a simple tool (numactl) to query and modify default thread/process
  policities.
* add documentation for the new syscalls, for numa and for numactl.
* re-enable first touch NUMA again by default, as now policies can be
  set in a variety of methods.

This is only relevant for very specific workloads.

This doesn't pretend to be a final NUMA solution.

The previous defaults in -HEAD (with MAXMEMDOM set) can be achieved by
'sysctl vm.default_policy=rr'.

This is only relevant if MAXMEMDOM is set to something other than 1.
Ie, if you're using GENERIC or a modified kernel with non-NUMA, then
this is a glorified no-op for you.

Thank you to Norse Corp for giving me access to rather large
(for FreeBSD!) NUMA machines in order to develop and verify this.

Thank you to Dell for providing me with dual socket sandybridge
and westmere v3 hardware to do NUMA development with.

Thank you to Scott Long at Netflix for providing me with access
to the two-socket, four-domain haswell v3 hardware.

Thank you to Peter Holm for running the stress testing suite
against the NUMA branch during various stages of development!

Tested:

* MIPS (regression testing; non-NUMA)
* i386 (regression testing; non-NUMA GENERIC)
* amd64 (regression testing; non-NUMA GENERIC)
* westmere, 2 socket (thankyou norse!)
* sandy bridge, 2 socket (thankyou dell!)
* ivy bridge, 2 socket (thankyou norse!)
* westmere-EX, 4 socket / 1TB RAM (thankyou norse!)
* haswell, 2 socket (thankyou norse!)
* haswell v3, 2 socket (thankyou dell)
* haswell v3, 2x18 core (thankyou scott long / netflix!)

* Peter Holm ran a stress test suite on this work and found one
  issue, but has not been able to verify it (it doesn't look NUMA
  related, and he only saw it once over many testing runs.)

* I've tested bhyve instances running in fixed NUMA domains and cpusets;
  all seems to work correctly.

Verified:

* intel-pcm - pcm-numa.x and pcm-memory.x, whilst selecting different
  NUMA policies for processes under test.

Review:

This was reviewed through phabricator (https://reviews.freebsd.org/D2559)
as well as privately and via emails to freebsd-arch@.  The git history
with specific attributes is available at https://github.com/erikarn/freebsd/
in the NUMA branch (https://github.com/erikarn/freebsd/compare/local/adrian_numa_policy).

This has been reviewed by a number of people (stas, rpaulo, kib, ngie,
wblock) but not achieved a clear consensus.  My hope is that with further
exposure and testing more functionality can be implemented and evaluated.

Notes:

* The VM doesn't handle unbalanced domains very well, and if you have an overly
  unbalanced memory setup whilst under high memory pressure, VM page allocation
  may fail leading to a kernel panic.  This was a problem in the past, but it's
  much more easily triggered now with these tools.

* This work only controls the path through vm_phys; it doesn't yet strongly/predictably
  affect contigmalloc, KVA placement, UMA, etc.  So, driver placement of memory
  isn't really guaranteed in any way.  That's next on my plate.

Sponsored by:	Norse Corp, Inc.; Dell
2015-07-11 15:21:37 +00:00
Mateusz Guzik
4ea6a9a28f Generalised support for copy-on-write structures shared by threads.
Thread credentials are maintained as follows: each thread has a pointer to
creds and a reference on them. The pointer is compared with proc's creds on
userspace<->kernel boundary and updated if needed.

This patch introduces a counter which can be compared instead, so that more
structures can use this scheme without adding more comparisons on the boundary.
2015-06-10 10:43:59 +00:00
Dmitry Chagin
91d1786f65 In preparation for switching linuxulator to the use the native 1:1
threads add a hook for cleaning thread resources before the thread die.

Differential Revision:	https://reviews.freebsd.org/D1038
2015-05-24 14:51:29 +00:00
Jung-uk Kim
fd90e2ed54 CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten
years for head.  However, it is continuously misused as the mpsafe argument
for callout_init(9).  Deprecate the flag and clean up callout_init() calls
to make them more consistent.

Differential Revision:	https://reviews.freebsd.org/D2613
Reviewed by:	jhb
MFC after:	2 weeks
2015-05-22 17:05:21 +00:00
Konstantin Belousov
100ac78be1 On amd64, make proc0 pmap initialization slightly more correct. In
particular, switch to the proc0 pmap to have expected %cr3 and PCID
for the thread0 during initialization, and the up to date pm_active
mask.

pmap_pinit0() should be done after proc0->p_vmspace is assigned so
that the amd64 pmap_activate() find the correct curproc pmap.

Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2015-05-15 08:30:29 +00:00
Devin Teske
43d4f8c4c6 Add "GELI Passphrase:" prompt to boot loader.
A new loader.conf(5) option of geom_eli_passphrase_prompt="YES" will now
allow you to enter your geli(8) root-mount credentials prior to invoking
the kernel.

See check-password.4th(8) for details.

Differential Revision:	https://reviews.freebsd.org/D2105
Reviewed by:	imp, kmoore
Discussed on:	-current
MFC after:	3 days
X-MFC-to:	stable/10
Relnotes:	yes
2015-04-16 20:53:15 +00:00
Mateusz Guzik
ffb34484ee cred: add proc_set_cred_init helper
proc_set_cred_init can be used to set first credentials of a new
process.

Update proc_set_cred assertions so that it only expects already used
processes.

This fixes panics where p_ucred of a new process happens to be non-NULL.

Reviewed by:	kib
2015-03-21 20:24:54 +00:00
Mateusz Guzik
daf63fd2f9 cred: add proc_set_cred helper
The goal here is to provide one place altering process credentials.

This eases debugging and opens up posibilities to do additional work when such
an action is performed.
2015-03-16 00:10:03 +00:00
Ian Lepore
b96bd95b85 Allow the kern.osrelease and kern.osreldate sysctl values to be set in a
jail's creation parameters.  This allows the kernel version to be reliably
spoofed within the jail whether examined directly with sysctl or
indirectly with the uname -r and -K options.

The values can only be set at jail creation time, to eliminate the need
for any locking when accessing the values via sysctl.

The overridden values are inherited by nested jails (unless the config for
the nested jails also overrides the values).

There is no sanity or range checking, other than disallowing an empty
release string or a zero release date, by design.  The system
administrator is trusted to set sane values.  Setting values that are
newer than the actual running kernel will likely cause compatibility
problems.

Differential Revision:	https://reviews.freebsd.org/D1948
Relnotes:	yes
2015-02-27 16:28:55 +00:00
John-Mark Gurney
9541307fb7 turn GEOM_UNCOMPRESS_DEBUG into a proper option so it can be specified
in kernel config files..

put VERBOSE_SYSINIT in it's own option header so the one file,
init_main.c, can use it instead of requiring an entire kernel recompile
to change one file..
2015-02-05 07:51:38 +00:00
Hans Petter Selasky
a115fb62ed Revert for r277213:
FreeBSD developers need more time to review patches in the surrounding
areas like the TCP stack which are using MPSAFE callouts to restore
distribution of callouts on multiple CPUs.

Bump the __FreeBSD_version instead of reverting it.

Suggested by:		kmacy, adrian, glebius and kib
Differential Revision:	https://reviews.freebsd.org/D1438
2015-01-22 11:12:42 +00:00
Hans Petter Selasky
1a26c3c047 Major callout subsystem cleanup and rewrite:
- Close a migration race where callout_reset() failed to set the
  CALLOUT_ACTIVE flag.
- Callout callback functions are now allowed to be protected by
  spinlocks.
- Switching the callout CPU number cannot always be done on a
  per-callout basis. See the updated timeout(9) manual page for more
  information.
- The timeout(9) manual page has been updated to reflect how all the
  functions inside the callout API are working. The manual page has
  been made function oriented to make it easier to deduce how each of
  the functions making up the callout API are working without having
  to first read the whole manual page. Group all functions into a
  handful of sections which should give a quick top-level overview
  when the different functions should be used.
- The CALLOUT_SHAREDLOCK flag and its functionality has been removed
  to reduce the complexity in the callout code and to avoid problems
  about atomically stopping callouts via callout_stop(). If someone
  needs it, it can be re-added. From my quick grep there are no
  CALLOUT_SHAREDLOCK clients in the kernel.
- A new callout API function named "callout_drain_async()" has been
  added. See the updated timeout(9) manual page for a complete
  description.
- Update the callout clients in the "kern/" folder to use the callout
  API properly, like cv_timedwait(). Previously there was some custom
  sleepqueue code in the callout subsystem, which has been removed,
  because we now allow callouts to be protected by spinlocks. This
  allows us to tear down the callout like done with regular mutexes,
  and a "td_slpmutex" has been added to "struct thread" to atomically
  teardown the "td_slpcallout". Further the "TDF_TIMOFAIL" and
  "SWT_SLEEPQTIMO" states can now be completely removed. Currently
  they are marked as available and will be cleaned up in a follow up
  commit.
- Bump the __FreeBSD_version to indicate kernel modules need
  recompilation.
- There has been several reports that this patch "seems to squash a
  serious bug leading to a callout timeout and panic".

Kernel build testing:	all architectures were built
MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D1438
Sponsored by:		Mellanox Technologies
Reviewed by:		jhb, adrian, sbruno and emaste
2015-01-15 15:32:30 +00:00
Konstantin Belousov
237623b028 Add a facility for non-init process to declare itself the reaper of
the orphaned descendants.  Base of the API is modelled after the same
feature from the DragonFlyBSD.

Requested by:	bapt
Reviewed by:	jilles (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2014-12-15 12:01:42 +00:00
Konstantin Belousov
5c7bebf961 The process spin lock currently has the following distinct uses:
- Threads lifetime cycle, in particular, counting of the threads in
  the process, and interlocking with process mutex and thread lock.
  The main reason of this is that turnstile locks are after thread
  locks, so you e.g. cannot unlock blockable mutex (think process
  mutex) while owning thread lock.

- Virtual and profiling itimers, since the timers activation is done
  from the clock interrupt context.  Replace the p_slock by p_itimmtx
  and PROC_ITIMLOCK().

- Profiling code (profil(2)), for similar reason.  Replace the p_slock
  by p_profmtx and PROC_PROFLOCK().

- Resource usage accounting.  Need for the spinlock there is subtle,
  my understanding is that spinlock blocks context switching for the
  current thread, which prevents td_runtime and similar fields from
  changing (updates are done at the mi_switch()).  Replace the p_slock
  by p_statmtx and PROC_STATLOCK().

The split is done mostly for code clarity, and should not affect
scalability.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-11-26 14:10:00 +00:00
Mateusz Guzik
eb48fbd963 filedesc: fixup fdinit to lock fdp and preapare files conditinally
Not all consumers providing fdp to copy from want files.

Perhaps these functions should be reorganized to better express the outcome.

This fixes up panics after r273895 .

Reported by:	markj
2014-11-13 21:15:09 +00:00
Mark Murray
10cb24248a This is the much-discussed major upgrade to the random(4) device, known to you all as /dev/random.
This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources.

The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people.

The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway.

Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to.

My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise.

My Nomex pants are on. Let the feedback commence!

Reviewed by:	trasz,des(partial),imp(partial?),rwatson(partial?)
Approved by:	so(des)
2014-10-30 21:21:53 +00:00
Davide Italiano
2be111bf7d Follow up to r225617. In order to maximize the re-usability of kernel code
in userland rename in-kernel getenv()/setenv() to kern_setenv()/kern_getenv().
This fixes a namespace collision with libc symbols.

Submitted by:   kmacy
Tested by:      make universe
2014-10-16 18:04:43 +00:00
Bryan Drewery
44f1c91610 Rename global cnt to vm_cnt to avoid shadowing.
To reduce the diff struct pcu.cnt field was not renamed, so
PCPU_OP(cnt.field) is still used. pc_cnt and pcpu are also used in
kvm(3) and vmstat(8). The goal was to not affect externally used KPI.

Bump __FreeBSD_version_ in case some out-of-tree module/code relies on the
the global cnt variable.

Exp-run revealed no ports using it directly.

No objection from:	arch@
Sponsored by:	EMC / Isilon Storage Division
2014-03-22 10:26:09 +00:00
John Baldwin
55648840de Extend the support for exempting processes from being killed when swap is
exhausted.
- Add a new protect(1) command that can be used to set or revoke protection
  from arbitrary processes.  Similar to ktrace it can apply a change to all
  existing descendants of a process as well as future descendants.
- Add a new procctl(2) system call that provides a generic interface for
  control operations on processes (as opposed to the debugger-specific
  operations provided by ptrace(2)).  procctl(2) uses a combination of
  idtype_t and an id to identify the set of processes on which to operate
  similar to wait6().
- Add a PROC_SPROTECT control operation to manage the protection status
  of a set of processes.  MADV_PROTECT still works for backwards
  compatability.
- Add a p_flag2 to struct proc (and a corresponding ki_flag2 to kinfo_proc)
  the first bit of which is used to track if P_PROTECT should be inherited
  by new child processes.

Reviewed by:	kib, jilles (earlier version)
Approved by:	re (delphij)
MFC after:	1 month
2013-09-19 18:53:42 +00:00
John Baldwin
edb572a38c Add a mmap flag (MAP_32BIT) on 64-bit platforms to request that a mapping use
an address in the first 2GB of the process's address space.  This flag should
have the same semantics as the same flag on Linux.

To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address.  While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.

Reviewed by:	alc
Approved by:	re (kib)
2013-09-09 18:11:59 +00:00
Olivier Houchard
662423aeaf Don't call sleepinit() from proc0_init(), make it a SYSINIT instead.
vmem needs the sleepq locks to be initialized when free'ing kva, so we want it
called as early as possible.
2013-08-09 23:13:52 +00:00
Jeff Roberson
5df87b21d3 Replace kernel virtual address space allocation with vmem. This provides
transparent layering and better fragmentation.

 - Normalize functions that allocate memory to use kmem_*
 - Those that allocate address space are named kva_*
 - Those that operate on maps are named kmap_*
 - Implement recursive allocation handling for kmem_arena in vmem.

Reviewed by:	alc
Tested by:	pho
Sponsored by:	EMC / Isilon Storage Division
2013-08-07 06:21:20 +00:00
Andriy Gapon
785797c341 rename scheduler->swapper and SI_SUB_RUN_SCHEDULER->SI_SUB_LAST
Also directly call swapper() at the end of mi_startup instead of
relying on swapper being the last thing in sysinits order.

Rationale:

- "RUN_SCHEDULER" was misleading, scheduling already takes place at that stage
- "scheduler" was misleading, the function swaps in the swapped out processes
- another SYSINIT(SI_SUB_RUN_SCHEDULER, SI_ORDER_ANY) could never be
  invoked depending on its relative order with scheduler; this was not obvious
  and the bug actually used to exist

Reviewed by:	kib (ealier version)
MFC after:	14 days
2013-07-24 09:45:31 +00:00
Brooks Davis
56fddc5d8c MFP4 change 210763
Allow boothowto and bootverbose to be set via kernel options, which
is useful on architectures that are unable to rely on a boot loader
to pass configuration variables to the kernel.

Submitted by:	rwatson
2013-04-03 22:24:36 +00:00
Andriy Gapon
bfdcb3bcba print compiler version in the kernel banner
And provide kernel compiler version as a sysctl as well.
This is useful while we have gcc and clang cohabitation.
This could be even more useful when we have support
for external toolchains.

In cooperation with:	mjg
MFC after:		13 days
2013-02-02 11:58:35 +00:00
Konstantin Belousov
f7e50ea722 Fix a race between kern_setitimer() and realitexpire(), where the
callout is started before kern_setitimer() acquires process mutex, but
looses a race and kern_setitimer() gets the process mutex before the
callout.  Then, assuming that new specified struct itimerval has
it_interval zero, but it_value non-zero, the callout, after it starts
executing again, clears p->p_realtimer.it_value, but kern_setitimer()
already rescheduled the callout.

As the result of the race, both p_realtimer is zero, and the callout
is rescheduled. Then, in the exit1(), the exit code sees that it_value
is zero and does not even try to stop the callout. This allows the
struct proc to be reused and eventually the armed callout is
re-initialized.  The consequence is the corrupted callwheel tailq.

Use process mutex to interlock the callout start, which fixes the race.

Reported and tested by:	pho
Reviewed by:	jhb
MFC after:	2 weeks
2012-12-04 20:49:39 +00:00
Konstantin Belousov
abce621c3a Fix grammar.
Submitted by:	jh
MFC after:	1 week
2012-08-16 13:01:56 +00:00
Konstantin Belousov
02c6fc2114 Add a sysctl kern.pid_max, which limits the maximum pid the system is
allowed to allocate, and corresponding tunable with the same
name. Note that existing processes with higher pids are left intact.

MFC after:	1 week
2012-08-15 15:56:21 +00:00
John Baldwin
b871e6613b Extend VERBOSE_SYSINIT to also print out the name of variables passed
to SYSINIT routines if they can be resolved via symbol look up in DDB.
To avoid false positives, only honor a name if the symbol resolves
exactly to the pointer value (no offset).

MFC after:	1 week
2012-06-01 15:42:37 +00:00
Pawel Jakub Dawidek
9b9a01792d TDF_* flags should be used with td_flags field and TDP_* flags should be used
with td_pflags field. Correct two places where it was not the case.

Discussed with:	kib
MFC after:	1 week
2012-01-22 11:01:36 +00:00
Sergey Kandaurov
3bedc94069 Remove the long reprecated ``/stand/sysinstall'' from the init_path.
It can be put back using the INIT_PATH config option or init_path
loader variable, if still needed (which I doubt).

MFC after:	1 week
2011-10-27 10:25:11 +00:00