changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.
2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.
3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.
4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.
5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.
6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.
Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
notifications when LIO operations completed. These were the problems
with LIO event complete notification:
- Move all LIO/AIO event notification into one general function
so we don't have bugs in different data paths. This unification
got rid of several notification bugs one of which if kqueue was
used a SIGILL could get sent to the process.
- Change the LIO event accounting to count all AIO request that
could have been split across the fast path and daemon mode.
The prior accounting only kept track of AIO op's in that
mode and not the entire list of operations. This could cause
a bogus LIO event complete notification to occur when all of
the fast path AIO op's completed and not the AIO op's that
ended up queued for the daemon.
Suggestions from: alc
opt_device_polling.h
- Include opt_device_polling.h into appropriate files.
- Embrace with HAVE_KERNEL_OPTION_HEADERS the include in the files that
can be compiled as loadable modules.
Reviewed by: bde
the MAC result, as well as avoid losing the DAC check result when MAC
is enabled.
MFC after: 3 days
Reported by: Patrick LeBlanc <Patrick dot LeBlanc at sparta dot com>
framework. This makes Giant protection around MAC operations which inter-
act with VFS conditional, based on the MPSAFE status of the file system.
Affected the following syscalls:
o __mac_get_fd
o __mac_get_file
o __mac_get_link
o __mac_set_fd
o __mac_set_file
o __mac_set_link
-Drop Giant all together in __mac_set_proc because the
mac_cred_mmapped_drop_perms_recurse routine no longer requires it.
-Move conditional Giant aquisitions to after label allocation routines.
-Move the conditional release of Giant to before label de-allocation
routines.
Discussed with: rwatson
dedicated sysctl handlers. Protect manipulations with
poll_mtx. The affected sysctls are:
- kern.polling.burst_max
- kern.polling.each_burst
- kern.polling.user_frac
- kern.polling.reg_frac
o Use CTLFLAG_RD on MIBs that supposed to be read-only.
o u_int32t -> uint32_t
o Remove unneeded locking from poll_switch().
possible for do_execve() to call exit1() rather than returning. As a
result, the sequence "allocate memory; call kern_execve; free memory"
can end up leaking memory.
This commit documents this astonishing behaviour and adds a call to
exec_free_args() before the exit1() call in do_execve(). Since all
the users of kern_execve() in the tree use exec_free_args() to free
the command-line arguments after kern_execve() returns, this should
be safe, and it fixes the memory leak which can otherwise occur.
Submitted by: Peter Holm
MFC after: 3 days
Security: Local denial of service
calling sysctl_out_proc(). -- fix from jhb
Move the code in fill_kinfo_thread() that gathers data from struct proc
into the new function fill_kinfo_proc_only().
Change all callers of fill_kinfo_thread() to call both
fill_kinfo_proc_only() and fill_kinfo() thread. When gathering
data from a multi-threaded process, fill_kinfo_proc_only() only needs
to be called once.
Grab sched_lock before accessing the process thread list or calling
fill_kinfo_thread().
PR: kern/84684
MFC after: 3 days
o Axe poll in trap.
o Axe IFF_POLLING flag from if_flags.
o Rework revision 1.21 (Giant removal), in such a way that
poll_mtx is not dropped during call to polling handler.
This fixes problem with idle polling.
o Make registration and deregistration from polling in a
functional way, insted of next tick/interrupt.
o Obsolete kern.polling.enable. Polling is turned on/off
with ifconfig.
Detailed kern_poll.c changes:
- Remove polling handler flags, introduced in 1.21. The are not
needed now.
- Forget and do not check if_flags, if_capenable and if_drv_flags.
- Call all registered polling handlers unconditionally.
- Do not drop poll_mtx, when entering polling handlers.
- In ether_poll() NET_LOCK_GIANT prior to locking poll_mtx.
- In netisr_poll() axe the block, where polling code asks drivers
to unregister.
- In netisr_poll() and ether_poll() do polling always, if any
handlers are present.
- In ether_poll_[de]register() remove a lot of error hiding code. Assert
that arguments are correct, instead.
- In ether_poll_[de]register() use standard return values in case of
error or success.
- Introduce poll_switch() that is a sysctl handler for kern.polling.enable.
poll_switch() goes through interface list and enabled/disables polling.
A message that kern.polling.enable is deprecated is printed.
Detailed driver changes:
- On attach driver announces IFCAP_POLLING in if_capabilities, but
not in if_capenable.
- On detach driver calls ether_poll_deregister() if polling is enabled.
- In polling handler driver obtains its lock and checks IFF_DRV_RUNNING
flag. If there is no, then unlocks and returns.
- In ioctl handler driver checks for IFCAP_POLLING flag requested to
be set or cleared. Driver first calls ether_poll_[de]register(), then
obtains driver lock and [dis/en]ables interrupts.
- In interrupt handler driver checks IFCAP_POLLING flag in if_capenable.
If present, then returns.This is important to protect from spurious
interrupts.
Reviewed by: ru, sam, jhb
to avoid touching pageable memory while holding a mutex.
Simplify argument list replacement logic.
PR: kern/84935
Submitted by: "Antoine Pelisse" apelisse AT gmail.com (in a different form)
MFC after: 3 days
Add a new private thread flag to indicate that the thread should
not sleep if runningbufspace is too large.
Set this flag on the bufdaemon and syncer threads so that they skip
the waitrunningbufspace() call in bufwrite() rather than than
checking the proc pointer vs. the known proc pointers for these two
threads. A way of preventing these threads from being starved for
I/O but still placing limits on their outstanding I/O would be
desirable.
Set this flag in ffs_copyonwrite() to prevent bufwrite() calls from
blocking on the runningbufspace check while holding snaplk. This
prevents snaplk from being held for an arbitrarily long period of
time if runningbufspace is high and greatly reduces the contention
for snaplk. The disadvantage is that ffs_copyonwrite() can start
a large amount of I/O if there are a large number of snapshots,
which could cause a deadlock in other parts of the code.
Call runningbufwakeup() in ffs_copyonwrite() to decrement runningbufspace
before attempting to grab snaplk so that I/O requests waiting on
snaplk are not counted in runningbufspace as being in-progress.
Increment runningbufspace again before actually launching the
original I/O request.
Prior to the above two changes, the system could deadlock if enough
I/O requests were blocked by snaplk to prevent runningbufspace from
falling below lorunningspace and one of the bawrite() calls in
ffs_copyonwrite() blocked in waitrunningbufspace() while holding
snaplk.
See <http://www.holm.cc/stress/log/cons143.html>
bio may have been freed and reassigned by the wakeup before being
tested after releasing the bdonelock.
There's a non-zero chance this is the cause of a few of the crashes
knocking around with biodone() sitting in the stack backtrace.
Reviewed By: phk@
subdrivers to hook up.
It should probably be rewritten to implement a simple bus to which
the sub drivers attach using some kind of hint.
Until then, provide a couple of crutch functions with big warning
signs so it can survive the recent changes to struct resource.
osf1_signal.c:1.41, amd64/amd64/trap.c:1.291, linux_socket.c:1.60,
svr4_fcntl.c:1.36, svr4_ioctl.c:1.23, svr4_ipc.c:1.18, svr4_misc.c:1.81,
svr4_signal.c:1.34, svr4_stat.c:1.21, svr4_stream.c:1.55,
svr4_termios.c:1.13, svr4_ttold.c:1.15, svr4_util.h:1.10,
ext2_alloc.c:1.43, i386/i386/trap.c:1.279, vm86.c:1.58,
unaligned.c:1.12, imgact_elf.c:1.164, ffs_alloc.c:1.133:
Now that Giant is acquired in uprintf() and tprintf(), the caller no
longer leads to acquire Giant unless it also holds another mutex that
would generate a lock order reversal when calling into these functions.
Specifically not backed out is the acquisition of Giant in nfs_socket.c
and rpcclnt.c, where local mutexes are held and would otherwise violate
the lock order with Giant.
This aligns this code more with the eventual locking of ttys.
Suggested by: bde
of whether or not Giant was picked up by the filesystem. Add VFS_LOCK_GIANT
macros around vrele as it's possible that this can call in the VOP_INACTIVE
filesystem specific code. Also while we are here, remove the Giant assertion.
from the sysctl handler, we do not actually require Giant here so we
shouldn't assert it. Doing so will just complicate things when Giant is removed
from the sysctl framework.
sleep lock status while kdb_active, or we risk contending with the
mutex on another CPU, resulting in a panic when using "show
lockedvnods" while in DDB.
MFC after: 3 days
Reviewed by: jhb
Reported by: kris
the per-cpu data for all CPUs. This is easier to ask users to do than
"figure out how many CPUs you have, now run show pcpu, then run it
once for each CPU you have".
MFC after: 3 days
the vast majority of cases, these functions are called without mutexes
held, meaning that in all but two cases, there will be no ordering
issues with doing this, and it will eliminate the need for changes in
the caller. In two cases, mutexes are held, so Giant must be acquired
before those mutexes such that uprintf() and tprintf() recurse Giant
rather than generating a lock order reversal.
Suggested by: bde
remove the unconditional acquisition of Giant for extended attribute related
operations. If the file system is set as being MP safe and debug.mpsafevfs is
1, do not pickup Giant.
Mark the following system calls as being MP safe so we no longer pickup Giant
in the system call handler:
o extattrctl
o extattr_set_file
o extattr_get_file
o extattr_delete_file
o extattr_set_fd
o extattr_get_fd
o extattr_delete_fd
o extattr_set_link
o extattr_get_link
o extattr_delete_link
o extattr_list_file
o extattr_list_link
o extattr_list_fd
-Pass MPSAFE flags to namei(9) lookup and introduce vfslocked variable which
will keep track of any Giant acquisitions.
-Wrap any fd operations which manipulate vnodes in VFS_{UN}LOCK_GIANT
-Drop VFS_ASSERT_GIANT into function which operate on vnodes to ensure that
we are sufficiently protected.
I've tested these changes with various TrustedBSD MAC policies which use
extended attribute a lot on SMP and UP systems (thanks to Scott Long for
making some SMP hardware available to me for testing).
Discussed with: jeff
Requested by: jhb, rwatson
The external part is still called 'struct resource' but the contents
is now visible to drivers etc. This makes it part of the device
driver ABI so it not be changed lightly. A comment to this effect
is in place.
The internal part is called 'struct resource_i' and contain its external
counterpart as one field.
Move the bus_space tag+handle into the external struct resource, this
removes the need for device drivers to even know about these fields
in order to use bus_space to access hardware. (More in following commit).
and bus_free_resources(). These functions take a list of resources
and handle them all in one go. A flag makes it possible to mark
a resource as optional.
A typical device driver can save 10-30 lines of code by using these.
Usage examples will follow RSN.
MFC: A good idea, eventually.
It confuses the lock manager since in some places thread0 is
then used for vnode locking while curthread is used for vnode unlocking.
Found by: Yahoo!
Reviewed by: ps@,jhb@
MFC after: 3 days
a thread holding critical resource, e.g mutex or other implicit
synchronous flags. Give thread which exceeds nice threshold a minimum
time slice.
PR: kern/86087
NULL. The NFS client expects that a thread will always be present for a
VOP so that it can check for signal conditions, and will dereference a
NULL pointer if one isn't present.
MFC after: 3 days
nor uprintf() is believed to perform tsleep() or msleep() as written,
as ttycheckoutq() is called with '0' as its sleep argument.
Remove recently added WITNESS warnings for sleep as the comment was
incorrect. This should silence a warning from the nfs_timer() code.
Discussed with: bde
Give DEVFS a proper inode called struct cdev_priv. It is important
to keep in mind that this "inode" is shared between all DEVFS
mountpoints, therefore it is protected by the global device mutex.
Link the cdev_priv's into a list, protected by the global device
mutex. Keep track of each cdev_priv's state with a flag bit and
of references from mountpoints with a dedicated usecount.
Reap the benefits of much improved kernel memory allocator and the
generally better defined device driver APIs to get rid of the tables
of pointers + serial numbers, their overflow tables, the atomics
to muck about in them and all the trouble that resulted in.
This makes RAM the only limit on how many devices we can have.
The cdev_priv is actually a super struct containing the normal cdev
as the "public" part, and therefore allocation and freeing has moved
to devfs_devs.c from kern_conf.c.
The overall responsibility is (to be) split such that kern/kern_conf.c
is the stuff that deals with drivers and struct cdev and fs/devfs
handles filesystems and struct cdev_priv and their private liason
exposed only in devfs_int.h.
Move the inode number from cdev to cdev_priv and allocate inode
numbers properly with unr. Local dirents in the mountpoints
(directories, symlinks) allocate inodes from the same pool to
guarantee against overlaps.
Various other fields are going to migrate from cdev to cdev_priv
in the future in order to hide them. A few fields may migrate
from devfs_dirent to cdev_priv as well.
Protect the DEVFS mountpoint with an sx lock instead of lockmgr,
this lock also protects the directory tree of the mountpoint.
Give each mountpoint a unique integer index, allocated with unr.
Use it into an array of devfs_dirent pointers in each cdev_priv.
Initially the array points to a single element also inside cdev_priv,
but as more devfs instances are mounted, the array is extended with
malloc(9) as necessary when the filesystem populates its directory
tree.
Retire the cdev alias lists, the cdev_priv now know about all the
relevant devfs_dirents (and their vnodes) and devfs_revoke() will
pick them up from there. We still spelunk into other mountpoints
and fondle their data without 100% good locking. It may make better
sense to vector the revoke event into the tty code and there do a
destroy_dev/make_dev on the tty's devices, but that's for further
study.
Lots of shuffling of stuff and churn of bits for no good reason[2].
XXX: There is still nothing preventing the dev_clone EVENTHANDLER
from being invoked at the same time in two devfs mountpoints. It
is not obvious what the best course of action is here.
XXX: comment out an if statement that lost its body, until I can
find out what should go there so it doesn't do damage in the meantime.
XXX: Leave in a few extra malloc types and KASSERTS to help track
down any remaining issues.
Much testing provided by: Kris
Much confusion caused by (races in): md(4)
[1] You are not supposed to understand anything past this point.
[2] This line should simplify life for the peanut gallery.
as they both interact with the tty code (!MPSAFE) and may sleep if the
tty buffer is full (per comment).
Modify all consumers of uprintf() and tprintf() to hold Giant around
calls into these functions. In most cases, this means adding an
acquisition of Giant immediately around the function. In some cases
(nfs_timer()), it means acquiring Giant higher up in the callout.
With these changes, UFS no longer panics on SMP when either blocks are
exhausted or inodes are exhausted under load due to races in the tty
code when running without Giant.
NB: Some reduction in calls to uprintf() in the svr4 code is probably
desirable.
NB: In the case of nfs_timer(), calling uprintf() while holding a mutex,
or even in a callout at all, is a bad idea, and will generate warnings
and potential upset. This needs to be fixed, but was a problem before
this change.
NB: uprintf()/tprintf() sleeping is generally a bad ideas, as is having
non-MPSAFE tty code.
MFC after: 1 week
provided access to the root file system before the start of the
init process. This was used briefly by SEBSD before it knew about
preloading data in the loader, and using that method to gain
access to data earlier results in fewer inconsistencies in the
approach. Policy modules still have access to the root file system
creation event through the mac_create_mount() entry point.
Removed now, and will be removed from RELENG_6, in order to gain
third party policy dependencies on the entry point for the lifetime
of the 6.x branch.
MFC after: 3 days
Submitted by: Chris Vance <Christopher dot Vance at SPARTA dot com>
Sponsored by: SPARTA
so that UUIDs can be generated from within the kernel. The uuidgen(2)
syscall now allocates kernel memory, calls the generator, and does a
copyout() for the whole UUID store. This change is in support of GPT.
and other applications to query the state of the stack regarding the
accept queue on a listen socket:
SO_LISTENQLIMIT Return the value of so_qlimit (socket backlog)
SO_LISTENQLEN Return the value of so_qlen (complete sockets)
SO_LISTENINCQLEN Return the value of so_incqlen (incomplete sockets)
Minor white space tweaks to existing socket options to make them
consistent.
Discussed with: andre
MFC after: 1 week
quite a bit of reading to figure it out, and I want to avoid figuring
it out again.
Convert an if (foo) else printf("this is almost a panic") into a
KASSERT.
MFC after: 3 days
unconditional acquisition of Giant for ACL related operations. If the file
system is set as being MP safe and debug.mpsafevfs is 1, do not pickup
giant.
For any operations which require namei(9) lookups:
__acl_get_file
__acl_get_link
__acl_set_file
__acl_set_link
__acl_delete_file
__acl_delete_link
__acl_aclcheck_file
__acl_aclcheck_link
-Set the MPSAFE flag in NDINIT
-Initialize vfslocked variable using the NDHASGIANT macro
For functions which operate on fds, make sure the operations are locked:
__acl_get_fd
__acl_set_fd
__acl_delete_fd
__acl_aclcheck_fd
-Initialize vfslocked using VFS_LOCK_GIANT before we manipulate the vnode
Discussed with: jeff
any other non-sleepable lock. In plain English: Giant comes before all
other mutexes.
- Add some extra description to the lock order reversal printf's to indicate
when a reversal is triggered by a hard-coded implicit rule.
Requested by: truckman (2)
MFC after: 1 week
state where sleeping on a sleep queue is not allowed. The facility
doesn't support recursion but uses a simple private per-thread flag
(TDP_NOSLEEPING). The sleepq_add() function will panic if the flag is
set and INVARIANTS is enabled.
- Use this new facility to replace the g_xup and g_xdown mutexes that were
(ab)used to achieve similar behavior.
- Disallow sleeping in interrupt threads when invoking interrupt handlers.
MFC after: 1 week
Reviewed by: phk
links and the execution of ELF binaries. Two problems were found:
1) The link path wasn't tagged as being MP safe and thus was not properly
protected.
2) The ELF interpreter vnode wasnt being locked in namei(9) and thus was
insufficiently protected.
This commit makes the following changes:
-Sets the MPSAFE flag in NDINIT for symbolic link paths
-Sets the MPSAFE flag in NDINIT and introduce a vfslocked variable which
will be used to instruct VFS_UNLOCK_GIANT to unlock Giant if it has been
picked up.
-Drop in an assertion into vfs_lookup which ensures that if the MPSAFE
flag is NOT set, that we have picked up giant. If not panic (if WITNESS
compiled into the kernel). This should help us find conditions where vnode
operations are in-sufficiently protected.
This is a RELENG_6 candidate.
Discussed with: jeff
MFC after: 4 days
shutdown procedures (which have a duration of more than 120 seconds).
We have two user-space affecting shutdown timeouts: a "soft" one in
/etc/rc.shutdown and a "hard" one in init(8). The first one can be
configured via /etc/rc.conf variable "rcshutdown_timeout" and defaults
to 30 seconds. The second one was originally (in 1998) intended to be
configured via sysctl(8) variable "kern.shutdown_timeout" and defaults
to 120 seconds.
Unfortunately, the "kern.shutdown_timeout" was declared "unused" in 1999
(as it obviously is actually not used within the kernel itself) and
hence was intentionally but misleadingly removed in revision 1.107 from
init_main.c. Kernel sysctl(8) variables are certainly a wrong way to
control user-space processes in general, but in this particular case the
sysctl(8) variable should have remained as it supports init(8), which
isn't passed command line flags (which in turn could have been set via
/etc/rc.conf), etc.
As there is already a similar "kern.init_path" sysctl(8) variable which
directly affects init(8), resurrect the init(8) shutdown timeout under
sysctl(8) variable "kern.init_shutdown_timeout". But this time document
it as being intentionally unused within the kernel and used by init(8).
Also document it in the manpages init(8) and rc.conf(5).
Reviewed by: phk
MFC after: 2 weeks
struct bufs that are persistently held by ext2fs. Ignore any buffers
with this flag in the code in boot() that counts "busy" and dirty
buffers and attempts to sync the dirty buffers, which is done before
attempting to unmount all the file systems during shutdown.
This fixes the problem caused by any ext2fs file systems that are
mounted at system shutdown time, which caused boot() to give up on
a non-zero number of buffers and skip the call to vfs_unmountall().
This left all the mounted file systems in a dirty state and caused
them to all require cleanup by fsck on reboot.
Move the two separate copies of the "busy" buffer test in boot()
to a separate function.
Nuke the useless spl() stuff in the ext2fs ULCK_BUF() macro.
Bring the PRINT_BUF_FLAGS definition in sys/buf.h up to date with
this and previous flag changes.
PR: kern/56675, kern/85163
Tested by: "Matthias Andree" matthias.andree at gmx.de
Reviewed by: bde
MFC after: 3 days
Also introduce an aclinit function which will be used to create the UMA zone
for use by file systems at system start up.
MFC after: 1 month
Discussed with: rwatson
instead. Detailed changelist:
o Add flags field to struct pollrec, to indicate that
are particular entry is being worked on.
o Define a macro PR_VALID() to check that a pollrec
is valid and pollable.
o Mark ISRs as mpsafe.
o ether_poll()
- Acquire poll_mtx while traversing pollrec array.
- Skip pollrecs, that are being worked on.
- Conditionally acquire Giant when entering handler.
o netisr_pollmore()
- Conditionally assert Giant.
- Acquire poll_mtx while working with statistics.
o netisr_poll()
- Conditionally assert Giant.
- Acquire poll_mtx while working with statistics
and traversing pollrec array.
o ether_poll_register(), ether_poll_deregister()
- Conditionally assert Giant.
- Acquire poll_mtx while working with pollrec array.
o poll_idle()
- Remove all strange manipulations with Giant.
In collaboration with: ru, pjd
In collaboration with: Oleg Bulyzhin <oleg rinet.ru>
In collaboration with: dima <_pppp mail.ru>
remaining % arguments because the varargs are now out of sync and
there is a risk that we might for instance dereference an integer
in a %s argument.
Sponsored by: Napatech.com
link proctree and allproc to Giant since that order is already implicitly
enforced.
- Use a goto to handle the case where we want to enforce a reversal before
calling isitmydescendant() in witness_checkorder() so that the logic is
easier to follow and so that it is easier to add more forced-reversal
cases in the future.
MFC after: 3 days
mutex.
- Don't panic if a spin lock is held too long inside _mtx_lock_spin() if
panicstr is set (meaning that we are already in a panic). Just keep
spinning forever instead.
o for() instead of while() looping over mbuf chain
o paren's around all flag checks
o more verbose function and purpose description
o some more style changes
Based on feedback from: sam
m_demote(m->m_next) if they wish to start at the second mbuf in chain.
o Test m_type with == instead of &.
o Check m_nextpkt against NULL instead of implicit 0.
Based on feedback from: sam
1. Walk the absolute list in reverse to prefer duplicated levels that have
a lower absolute setting, i.e. 800 Mhz/50% is better than 1600 Mhz/25% even
though both have the same actual frequency. This also removes the need to
check for already-modified levels since by definition, those will be added
later in the sorted list.
2. Compare the absolute settings for derived levels and don't use the new
level if it's higher. For example, a level of 800 Mhz/75% is preferable to
1600 Mhz/25% even though the latter has a lower total frequency.
This work is based on a patch from the submitter but reworked by myself.
Submitted by: Tijl Coosemans (tijl/ulyssis.org)
int prep, int how).
Copies the data portion of mbuf (chain) n starting from offset off
for length len to mbuf (chain) m. Depending on prep the copied
data will be appended or prepended. The function ensures that the
mbuf (chain) m will be fully writeable by making real (not refcnt)
copies of mbuf clusters. For the prepending the function returns
a pointer to the new start of mbuf chain m and leaves as much
leading space as possible in the new first mbuf.
Reviewed by: glebius
checking on mbuf's and mbuf chains. Set sanitize to 1 to garble
illegal things and have them blow up later when used/accessed.
m_sanity()'s main purpose is for KASSERT()'s and debugging of non-
kosher mbuf manipulation (of which we have a number of).
Reviewed by: glebius
any tags and packet headers. If "all" is set then the first mbuf
in the chain will be cleaned too.
This function is used before an mbuf, that arrived as packet with
m->flags & M_PKTHDR, is appended to an mbuf chain using m->m_next
(not m->m_nextpkt).
Reviewed by: glebius
but vm_map_wire() fails, then a vm object, vm map entries, and kernel_map
free space is leaked and (2) unwiring is handled automatically by
vm_map_remove().
Suggested by: tegge
- if minfd < fd_freefile (as is most often the case, since minfd is
usually 0), set it to fd_freefile.
- remove a call to fd_first_free() which duplicates work already done
by fdused().
This change results in a small but measurable speedup for processes
with large numbers (several thousands) of open files.
PR: kern/85176
Submitted by: Divacky Roman <xdivac02@stud.fit.vutbr.cz>
MFC after: 3 weeks
if an indirect relationship exists (keep both A->B->C and A->C).
This allows witness_checkorder() to use isitmychild() instead of
the much more expensive isitmydescendant() to check for valid lock
ordering.
Don't do an expensive tree walk to update the w_level values when
the tree is updated. Only update the w_level values when using the
debugger to display the tree.
Nuke the experimental "witness_watch > 1" mode that only compared
w_level for the two locks. This information is no longer maintained
at run time, and the use of isitmychild() in witness_checkorder
should bring performance close enough to the acceptable level that
this hack is not needed.
Report witness data structure allocation statistics under the
debug.witness sysctl.
Reviewed by: jhb
MFC after: 30 days
vlrureclaim() in vfs_subr.c 1.636 because waiting for the vnode
lock aggravates an existing race condition. It is also undesirable
according to the commit log for 1.631.
Fix the tiny race condition that remains by rechecking the vnode
state after grabbing the vnode lock and grabbing the vnode interlock.
Fix the problem of other threads being starved (which 1.636 attempted
to fix by removing LK_NOWAIT) by calling uio_yield() periodically
in vlrureclaim(). This should be more deterministic than hoping
that VOP_LOCK() without LK_NOWAIT will block, which may not happen
in this loop.
Reviewed by: kan
MFC after: 5 days
is a workaround for non-symetric teardown of the file systems at
shutdown with respect to the mount order at boot. The proper long term
fix is to properly detach devfs from the root mount before unmounting
each, and should be implemented, but since the problem is non-harmful,
this temporary band-aid will prevent false positive bug reports and
unnecessary error output for 6.0-RELEASE.
MFC after: 3 days
Tested by: pav, pjd
points in lookup(). The lock can be dropped safely around VFS_ROOT because
LOCKPARENT semantics with child and perent vnodes coming from different FSes
does not really have any meaningful use. On the other hard, this prevents
easily triggered deadlock on systems using automounter daemon.
vm_pager_init() is run before required nswbuf variable has been set
to correct value. This caused system to run with single pbuf available
for vnode_pager. Handle both cluster_pbuf_freecnt and vnode_pbuf_freecnt
variable in the same way.
Reported by: ade
Obtained from: alc
MFC after: 2 days
list lock, as there has been a report that an alternative lock order
is getting introduced. This should help ferret it out.
Reported by: Ed Maste <emaste at phaedrus dot sandvine dot ca>
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags. Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags. This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.
Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.
Reviewed by: pjd, bz
MFC after: 7 days
not holding any non-sleep-able-locks locks when copyin is called.
This gets executed un-conditionally since we have no function
to wire the buffer in this direction.
Pointed out by: truckman
MFC after: 1 week
event handler, dev_clone, which accepts a credential argument.
Implementors of the event can ignore it if they're not interested,
and most do. This avoids having multiple event handler types and
fall-back/precedence logic in devfs.
This changes the kernel API for /dev cloning, and may affect third
party packages containg cloning kernel modules.
Requested by: phk
MFC after: 3 days
the buffer has not been wired and we are holding any non-sleep-able locks,
drop a witness warning. If the buffer has not been wired, it is possible
that the writing of the data can sleep, especially if the page is not in
memory. This can result in a number of different locking issues, including
dead locks.
MFC after: 1 week
Discussed with: rwatson
Reviewed by: jhb
integer to an unsigned long. This lifts variables like the maximum
number of pages available for shared memory from 2^31 to 2^32 on 32
bit architectures, and from 2^31 to 2^64 on 64 bit architectures.
It should be noted that this changes breaks ABI on 64 bit architectures
because the size of the shmmax, shmmin, shmmni, shmseg and shmall members
of the shminfo structure has changed.
Silence on: current@
vnode is inactivated), possibly leading to a NULL dereference when
checking if the mount wants knotes to be activated in the VOP hooks.
So, we add a new vnode flag VV_NOKNOTE that is only set in getnewvnode(),
if necessary, and check it when activating knotes.
Since the flags are not erased when a vnode is being held, we can safely
read them.
Reviewed by: kris@
MFC after: 3 days
lists, as well as accessor macros. For now, this is a recursive mutex
due code sequences where IPv4 multicast calls into IGMP calls into
ip_output(), which then tests for a multicast forwarding case.
For support macros in in_var.h to check multicast address lists, assert
that in_multi_mtx is held.
Acquire in_multi_mtx around iteration over the IPv4 multicast address
lists, such as in ip_input() and ip_output().
Acquire in_multi_mtx when manipulating the IPv4 layer multicast addresses,
as well as over the manipulation of ifnet multicast address lists in order
to keep the two layers in sync.
Lock down accesses to IPv4 multicast addresses in IGMP, or assert the
lock when performing IGMP join/leave events.
Eliminate spl's associated with IPv4 multicast addresses, portions of
IGMP that weren't previously expunged by IGMP locking.
Add in_multi_mtx, igmp_mtx, and if_addr_mtx lock order to hard-coded
lock order in WITNESS, in that order.
Problem reported by: Ed Maste <emaste at phaedrus dot sandvine dot ca>
MFC after: 10 days
caller by saving the stack of the last locker/unlocker in lockmgr. We
also put the stack in KTR at the moment.
Contributed by: Antoine Brodin <antoine.brodin@laposte.net>
kenv environment in kern_environment.c switches to dynamic kenv. The prior
call sets the static variable hintp to the static hints in subr_hints.c
(hintmode==0).
However, changes to the environment are not detected by the resource_xxx
lookups after the change to dynamic kernel environment, so the lookup
routines only report the old stuff of hintmode==0, even after the change to
the dynamic kenv. This causes kenv users to see a different environment than
the kernel routines.
This is a problem in the mixer.c code that looks up initial mixer volume
settings from the hints: If the hints are dynamic and not from the
device.hints file, mixer.c doesn't see them, but kenv does.
The patch from the PR (modified to comply to the style of the function)
solves this.
PR: 83686
Submitted by: Harry Coin <harrycoin@qconline.com>
This has no security implications since only root is allowed to use
kenv(1) (and corrupt the kernel memory after adding too much variables
previous to this commit).
This is based upon the PR [1] mentioned below, but extended to check both
bounds (in case of an overflow of the counting variable) and to comply
to the style of the function. An overflow of the counting variable
shouldn't happen after adding the check for the upper bound, but better
safe than sorry (in case some other function in the kernel overwrites
random memory).
An interested soul may want to add a printf to notify root in case the
bounds are hit.
Also allocate KENV_SIZE+1 entries (the array is NULL-terminated), since
the comment for KENV_SIZE says it's the maximum number of environment
strings. [2]
PR: 83687 [1]
Submitted by: Harry Coin <harrycoin@qconline.com> [1]
Submitted by: Ariff Abdullah <skywizard@MyBSD.org.my> [2]
was not compiled with 'options HWPMC_HOOKS' or if the compiled-in
version numbers of the kernel and module are out of sync.
Reported by: cracauer
MFC after: 3 days
Make sure that there actually is a next packet before setting
nextrecord to that field.
PR: 83885
Submitted by: hirose@comm.yamaha.co.jp
Obtained from: Patch suggested in the PR
MFC after: 1 week
- increase number of allocations count only on successfull malloc(9),
so it doesn't confuse people;
- because we need to check if 'size > 0', hide 'mtsp->mts_memalloced += size;'
under the check as well, as for size=0 it is of course a no-op;
- avoid critical_enter()/critical_exit() in case of failure in
malloc_type_allocated() as there will be nothing to do.
OK'ed by: rwatson
MFC after: 2 days
make the b_iodone callback responsible for setting it if it is needed.
Previously, it was set unconditionally by bufdone() without holding
whichever lock is shared by the b_iodone callback and the corresponding
top-half function. Consequently, in a race, the top-half function could
conclude that operation was done before the b_iodone callback finished.
See, for example, aio_physwakeup() and aio_fphysio().
Note: I don't believe that the other, more widely-used b_iodone callbacks
are affected.
Discussed with: jeff
Reviewed by: phk
MFC after: 2 weeks
vnlru proc is extremely inefficient, potentially iteration over tens of
thousands of vnodes without blocking. Droping Giant allows other threads
to preempt us although we should revisit the algorithm to fix the runtime
problems especially since this may hold up all vnode allocations.
- Remove the LK_NOWAIT from the VOP_LOCK in vlrureclaim. This provides
a natural blocking point to help alleviate the situation described above
although it may not technically be desirable.
- yield after we make a pass on all mount points to prevent us from
blocking other threads which require Giant.
MFC after: 2 weeks
hokie and much more readable and expand the comment to explain why it is
the way that it is.
- Close a race where one CPU could free the process belonging to a thread
on another CPU that hasn't quite finished exiting yet but is beyond the
point of setting the process state as PRS_ZOMBIE.
Reported and tested by: ps (2)
MFC after: 3 days
are string names for their respective UMA zones and malloc types, and
are passed into uma_zcreate() and MALLOC_DEFINE(). Export them
outside of _KERNEL in mbuf.h so that netstat can reference them.
Change the names to improve consistency, with each zone/type
associated with the mbuf allocator being prefixed mbuf_.
MFC after: 1 week
variables rather than void * variables. This makes it easier and simpler
to get asm constraints and volatile keywords correct.
MFC after: 3 days
Tested on: i386, alpha, sparc64
Compiled on: ia64, powerpc, amd64
Kernel toolchain busted on: arm
statistics via a binary structure stream:
- Add structure 'malloc_type_stream_header', which defines a stream
version, definition of MAXCPUS used in the stream, and a number of
malloc_type records in the stream.
- Add structure 'malloc_type_header', which defines the name of the
malloc type being reported on.
- When the sysctl is queried, return a stream header, followed by a
series of type descriptions, each consisting of a type header
followed by a series of MAXCPUS malloc_type_stats structures holding
per-CPU allocation information. Typical values of MAXCPUS will be 1
(UP compiled kernel) and 16 (SMP compiled kernel).
This query mechanism allows user space monitoring tools to extract
memory allocation statistics in a machine-readable form, and to do so
at a per-CPU granularity, allowing monitoring of allocation patterns
across CPUs in order to better understand the distribution of work and
memory flow over multiple CPUs.
While here:
- Bump statistics width to uint64_t, and hard code using fixed-width
type in order to be more sure about structure layout in the stream.
We allocate and free a lot of memory.
- Add kmemcount, a counter of the number of registered malloc types,
in order to avoid excessive manual counting of types. Export via a
new sysctl to allow user-space code to better size buffers.
- De-XXX comment on no longer maintaining the high watermark in old
sysctl monitoring code.
A follow-up commit of libmemstat(3), a library to monitor kernel memory
allocation, will occur in the next few days. Likewise, similar changes
to UMA.
process that caused the clone event to take place for the device driver
creating the device. This allows cloned device drivers to adapt the
device node based on security aspects of the process, such as the uid,
gid, and MAC label.
- Add a cred reference to struct cdev, so that when a device node is
instantiated as a vnode, the cloning credential can be exposed to
MAC.
- Add make_dev_cred(), a version of make_dev() that additionally
accepts the credential to stick in the struct cdev. Implement it and
make_dev() in terms of a back-end make_dev_credv().
- Add a new event handler, dev_clone_cred, which can be registered to
receive the credential instead of dev_clone, if desired.
- Modify the MAC entry point mac_create_devfs_device() to accept an
optional credential pointer (may be NULL), so that MAC policies can
inspect and act on the label or other elements of the credential
when initializing the skeleton device protections.
- Modify tty_pty.c to register clone_dev_cred and invoke make_dev_cred(),
so that the pty clone credential is exposed to the MAC Framework.
While currently primarily focussed on MAC policies, this change is also
a prerequisite for changes to allow ptys to be instantiated with the UID
of the process looking up the pty. This requires further changes to the
pty driver -- in particular, to immediately recycle pty nodes on last
close so that the credential-related state can be recreated on next
lookup.
Submitted by: Andrew Reisse <andrew.reisse@sparta.com>
Obtained from: TrustedBSD Project
Sponsored by: SPAWAR, SPARTA
MFC after: 1 week
MFC note: Merge to 6.x, but not 5.x for ABI reasons
syscalls.master for the master list and the Alpha/OSF1 compat ABI to be
consistent with all the other compat ABIs where 'make sysent' already
works.
MFC after: 3 days
address, writting non-canonical address can cause kernel a panic,
by restricting base values to 0..VM_MAXUSER_ADDRESS, ensuring
only canonical values get written to the registers.
Reviewed by: peter, Josepha Koshy < joseph.koshy at gmail dot com >
Approved by: re (scottl)
and writev() except that they take an additional offset argument and do
not change the current file position. In SAT speak:
preadv:readv::pread:read and pwritev:writev::pwrite:write.
- Try to reduce code duplication some by merging most of the old
kern_foov() and dofilefoo() functions into new dofilefoo() functions
that are called by kern_foov() and kern_pfoov(). The non-v functions
now all generate a simple uio on the stack from the passed in arguments
and then call kern_foov(). For example, read() now just builds a uio and
calls kern_readv() and pwrite() just builds a uio and calls kern_pwritev().
PR: kern/80362
Submitted by: Marc Olzheim marcolz at stack dot nl (1)
Approved by: re (scottl)
MFC after: 1 week
which is invoked from socket() and socketpair(), permitting MAC
policy modules to control the creation of sockets by domain, type, and
protocol.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA, SPAWAR
Approved by: re (scottl)
Requested by: SCC
- Introducing the possibility of using locks different than mutexes
for the knlist locking. In order to do this, we add three arguments to
knlist_init() to specify the functions to use to lock, unlock and
check if the lock is owned. If these arguments are NULL, we assume
mtx_lock, mtx_unlock and mtx_owned, respectively.
- Using the vnode lock for the knlist locking, when doing kqueue operations
on a vnode. This way, we don't have to lock the vnode while holding a
mutex, in filt_vfsread.
Reviewed by: jmg
Approved by: re (scottl), scottl (mentor override)
Pointyhat to: ssouhlal
Will be happy: everyone
- pmcstat(8) gprof output mode fixes:
lib/libpmc/pmclog.{c,h}, sys/sys/pmclog.h:
+ Add a 'is_usermode' field to the PMCLOG_PCSAMPLE event
+ Add an 'entryaddr' field to the PMCLOG_PROCEXEC event,
so that pmcstat(8) can determine where the runtime loader
/libexec/ld-elf.so.1 is getting loaded.
sys/kern/kern_exec.c:
+ Use a local struct to group the entry address of the image being
exec()'ed and the process credential changed flag to the exec
handling hook inside hwpmc(4).
usr.sbin/pmcstat/*:
+ Support "-k kernelpath", "-D sampledir".
+ Implement the ELF bits of 'gmon.out' profile generation in a new
file "pmcstat_log.c". Move all log related functions to this
file.
+ Move local definitions and prototypes to "pmcstat.h"
- Other bug fixes:
+ lib/libpmc/pmclog.c: correctly handle EOF in pmclog_read().
+ sys/dev/hwpmc_mod.c: unconditionally log a PROCEXIT event to all
attached PMCs when a process exits.
+ sys/sys/pmc.h: correct a function prototype.
+ Improve usage checks in pmcstat(8).
Approved by: re (blanket hwpmc)
This is good enough to be able to run a RELENG_4 gdb binary against
a RELENG_4 application, along with various other tools (eg: 4.x gcore).
We use this at work.
ia32_reg.[ch]: handle the 32 bit register file format, used by ptrace,
procfs and core dumps.
procfs_*regs.c: vary the format of proc/XXX/*regs depending on the client
and target application.
procfs_map.c: Don't print a 64 bit value to 32 bit consumers, or their
sscanf fails. They expect an unsigned long.
imgact_elf.c: produce a valid 32 bit coredump for 32 bit apps.
sys_process.c: handle 32 bit consumers debugging 32 bit targets. Note
that 64 bit consumers can still debug 32 bit targets.
IA64 has got stubs for ia32_reg.c.
Known limitations: a 5.x/6.x gdb uses get/setcontext(), which isn't
implemented in the 32/64 wrapper yet. We also make a tiny patch to
gdb pacify it over conflicting formats of ld-elf.so.1.
Approved by: re
ioctl numbers in backwards compatability mode. eg: an IOC_IN ioctl with
a size of zero. Traditionally this was what you did before IOC_VOID
existed, and we had some established users of this in the tree, namely
procfs. Certain 3rd party drivers with binary userland components also
have this too.
This is necessary to have 4.x and 5.x binaries use these ioctl's. We
found this at work when trying to run 4.x binaries.
Approved by: re
reporting - in my previous change, I missed the case where a mbuf
from the packet zone was freed back to the mbuf/packet keg, where
it was subsequently put into the mbuf zone and found not to contain
the expected trash. This change adds the necessary trash_dtor call inside
mb_fini_pack so that everything is correct.
Thanks for Bosko for finding the bug and showing me how secondary zones
work.
Approved by: re (dwhite)
opening a device, devfs_open needs the file descriptor to install its
own fileops. Failing to pass the file descriptor causes the vnode to
be returned with the regular vnops, which will cause a panic on the
first read or write because devfs_specops is not meant to support
those operations.
This bug caused a panic after exec'ing any set[ug]id program with
fds 0..2 closed (i.e., if any action had to be taken by fdcheckstd, we
would panic if the exec'd program ever tried to use any of those
descriptors).
Reviewed by: phk
Approved by: re (scottl)
the UMA "trash" allocator is used - this ensures that any writes to a freed
mbuf should provoke a panic.
Only enabled under INVARIANTS, of course.
Approved by: re (scottl)
#!-line had multiple whitespace characters after the interpreter name, and
it did not have any options, then the code would do nasty things trying to
process a (non-existent) option-string which "ended before it began"...
Submitted by: Morten Johansen
Approved by: re (dwhite)
are actually caused by a buf with both VNCLEAN and VNDIRTY set. In
the traces it is clear that the buf is removed from the dirty queue while
it is actually on the clean queue which leaves the tail pointer set.
Assert that both flags are not set in buf_vlist_add and buf_vlist_remove.
Sponsored by: Isilon Systems, Inc.
Approved by: re (blanket vfs)
cache_zap() to clear the v_dd pointers when a directory vnode is forcibly
discarded. For this to work, all vnodes with v_dd pointers to a directory
must also have name cache entries linked via v_cache_dst to that dvp
otherwise we could not find them at cache_purge() time. The following
code snipit could break this guarantee by unlinking a directory before
fetching it's dotdot. The dotdot lookup would initialize the v_dd field
of the unlinked directory which could never be cleared. To fix this
we don't initialize v_dd for orphaned vnodes.
printf("rmdir: %d\n", rmdir("../foo")); /* foo is cwd */
printf("chdir: %d\n", chdir(".."));
printf("%s\n", getwd(NULL));
Sponsored by: Isilon Systems, Inc.
Discovered by: kkenn
Approved by: re (blanket vfs)
ref while we're calling vgone(). This prevents transient refs from
re-adding us to the free list. Previously, a vfree() triggered via
vinvalbuf() getting rid of all of a vnode's pages could place a partially
destructed vnode on the free list where vtryrecycle() could find it. The
first call to vtryrecycle would hang up on the vnode lock, but when it
failed it would place a now dead vnode onto the free list, and another
call to vtryrecycle() would free an already free vnode. There were many
complications of having a zero ref count while freeing which can now go
away.
- Change vdropl() to release the interlock before returning. All callers
now respect this, so vdropl() directly frees VI_DOOMED vnodes once the
last ref is dropped. This means that we'll never have VI_DOOMED vnodes
on the free list.
- Seperate v_incr_usecount() into v_incr_usecount(), v_decr_usecount() and
v_decr_useonly(). The incr/decr split is so that incr usecount can
return with the interlock still held while decr drops the interlock so
it can call vdropl() which will potentially free the vnode. The calling
function can't drop the lock of an already free'd node. v_decr_useonly()
drops a usecount without droping the hold count. This is done so the
usecount reaches zero in vput() before we recycle, however the holdcount
is still 1 which prevents any new references from placing the vnode
back on the free list.
- Fix vnlrureclaim() to vhold the vnode since it doesn't do a vget(). We
wouldn't want vnlrureclaim() to bump the usecount since this has
different semantics. Also change vnlrureclaim() to do a NOWAIT on the
vn_lock. When this function runs we're usually in a desperate situation
and we wouldn't want to wait for any specific vnode to be released.
- Fix a bunch of misc comments to reflect the new behavior.
- Add vhold() and vdrop() to vflush() for the same reasons that we do in
vlrureclaim(). Previously we held no reference and a vnode could have
been freed while we were waiting on the lock.
- Get rid of vlruvp() and vfreehead(). Neither are used. vlruvp() should
really be rethought before it's reintroduced.
- vgonel() always returns with the vnode locked now and never puts the
vnode back on a free list. The vnode will be freed as soon as the last
reference is released.
Sponsored by: Isilon Systems, Inc.
Debugging help from: Kris Kennaway, Peter Holm
Approved by: re (blanket vfs)
of the clean and dirty lists. This is in an attempt to catch the wrong
bufobj problem sooner.
- In vgonel() don't acquire an extra reference in the active case, the
vnode lock and VI_DOOMED protect us from recursively cleaning.
- Also in vgonel() clean up some stale comments.
Sponsored by: Isilon Systems, Inc.
Approved by: re (blanket vfs)
used to ensure that we weren't exiting the syscall with a lock still
held. This wasn't safe, however, because we'd already executed a vput()
and on a loaded system the vnode may have been free'd by the time we
assert. This functionality is also handled by the td_locks assert in
userret, which doesn't tell you what the syscall was, but will at least
panic before you deadlock.
Sponsored by: Isilon Systems, Inc.
Discovred by: Peter Holm
Approved by: re (blanket vfs)
