'show lockchain'. The churn is because I'm about to add a new
'show sleepchain' similar to 'show lockchain' for sleep locks (lockmgr and
sx) and 'show threadchain' was a bit ambiguous as both commands show
a chain of thread dependencies, 'lockchain' is for non-sleepable locks
(mtx and rw) and 'sleepchain' is for sleepable locks.
image_params arg.
- Change struct image_params to include struct sysentvec pointer and
initialize it.
- Change all consumers of process_exit/process_exec eventhandlers to
new prototypes (includes splitting up into distinct exec/exit functions).
- Add eventhandler to userret.
Sponsored by: Google SoC 2006
Submitted by: rdivacky
Parts suggested by: jhb (on hackers@)
synchronized by the lock on the object containing the page.
Transition PG_WANTED and PG_SWAPINPROG to use the new field,
eliminating the need for holding the page queues lock when setting
or clearing these flags. Rename PG_WANTED and PG_SWAPINPROG to
VPO_WANTED and VPO_SWAPINPROG, respectively.
Eliminate the assertion that the page queues lock is held in
vm_page_io_finish().
Eliminate the acquisition and release of the page queues lock
around calls to vm_page_io_finish() in kern_sendfile() and
vfs_unbusy_pages().
a file system, but need to obtain a vnode. We may not be able to do it, because
all vnodes could be already in use and other processes cannot release them,
because they are waiting in "suspfs" state.
In such situation, we allow to allocate a vnode anyway.
This is a temporary fix - there is no backpressure to free vnodes allocated in
those circumstances.
MFC after: 1 week
Reviewed by: tegge
uipc_proto.c to uipc_usrreq.c, making localdomain static. Remove
uipc_proto.c as it's no longer used. With this change, UNIX domain
sockets are entirely encapsulated in uipc_usrreq.c.
sofree(), as a number of protocols expect to be able to call
soisdisconnected() during detach. That may not be a good assumption,
but until I'm sure if it's a good assumption or not, allow it.
vfs_rel() on the mountpoint if the MAC checks fail in kern_statfs() and
kern_fstatfs(). Similarly, don't perform an extra vfs_rel() if we get
a doomed vnode in kern_fstatfs(), and handle the case of mp being NULL
(for some doomed vnodes) by conditionalizing the vfs_rel() in
kern_fstatfs() on mp != NULL.
CID: 1517
Found by: Coverity Prevent (tm) (kern_fstatfs())
Pointy hat to: jhb
eliminating a second set of identical mutex operations at the bottom.
This allows brief exceeding of the max sockets limit, but only by
sockets in the last stages of being torn down.
- If we fail to register the system call during MOD_LOAD, then note that
so that we don't try to deregister it or invoke the chained event handler
during the subsequent MOD_UNLOAD event. Doing the deregister when the
register failed could result in trashing system call entries.
- Add a SI_SUB_SYSCALLS just before starting up init and use that to
register syscall modules instead of SI_SUB_DRIVERS. Registering system
calls as late as possible increases the chances that any other module
event handlers or SYSINITs in a module are executed to initialize the
data in a kld before a syscall dependent on that data is able to be
invoked.
MFC after: 3 days
longer referenced by other threads (hence our freeing it), we don't need
to set the can't send and can't receive flags, wake up the consumers,
perform two levels of locking, etc. Implement a fast-path teardown,
sbdestroy(), which flushes and releases each socket buffer. A manual
dom_dispose of the receive buffer is still required explicitly to GC
any in-flight file descriptors, etc, before flushing the buffer.
This results in a 9% UP performance improvement and 16% SMP performance
improvement on a tight loop of socket();close(); in micro-benchmarking,
but will likely also affect CPU-bound macro-benchmark performance.
UNIX domain socket at the same time as the remote host is closing the
new connections as quickly as they open. Since the connect() and
send() paths are non-atomic with respect to another, it is possible
for the second thread's close() call to disconnect the two sockets
as connect() returns, leading to the consumer (which plans to send())
with a NULL kernel pointer to its proposed peer. As a result, after
acquiring the UNIX domain socket subsystem lock, we need to revalidate
the connection pointers even though connect() has technically succeed,
and reurn an error to say that there's no connection on which to
perform the send.
We might want to rethink the specific errno number, perhaps ECONNRESET
would be better.
PR: 100940
Reported by: Young Hyun <youngh at caida dot org>
MFC after: 2 weeks
MFC note: Some adaptation will be required
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.
a count of all non-spin locks, not just lockmgr locks. This can give us a
much cheaper way to see if we have any locks held (such as when returning
to userland via userret()) without requiring WITNESS.
MFC after: 1 week
kern_fstatfs() so that it is still held when prison_enforce_statfs() is
called (since that function likes to poke and prod at the mountpoint
structure).
MFC after: 3 days
all other mtx_lock() operations to block. Previously, when the mutex was
destroyed, it would still have a valid value in mtx_lock(): either the
unowned cookie, which would allow a subsequent mtx_lock() to succeed, or a
pointer to the thread who destroyed the mutex if the mutex was locked when
it was destroyed.
MFC after: 3 days
kern_accept() and accept1(). If another thread closed the new file
descriptor and the first thread later got an error trying to copyout the
socket address, then it would attempt to close the wrong file object. To
fix, add a struct file ** argument to kern_accept(). If it is non-NULL,
then on success kern_accept() will store a pointer to the new file object
there and not release any of the references. It is up to the calling code
to drop the references appropriately (including a call to fdclose() in case
of error to safely handle the aforementioned race). While I'm at it, go
ahead and fix the svr4 streams code to not leak the accept fd if it gets an
error trying to copyout the streams structures.
have been invoked by uipc_close() or uipc_abort(), and the socket is in a
state of being torn down by the time we get to this point, so kqueue
state frobbed by soisdisconnected() is not available, so frobbing it will
result in a panic.
Reported by: Munehiro Matsuda <haro at h4 dot dion dot ne dot jp>
specific routines from uipc_socket2.c following repo-copy. We might
rethink the location of one or two at some point, but the division was
relatively clean. uipc_sockbuf.c is now the home of routines that
manipulate socket buffers.
soreceive(), and sopoll(), which are wrappers for pru_sosend,
pru_soreceive, and pru_sopoll, and are now used univerally by socket
consumers rather than either directly invoking the old so*() functions
or directly invoking the protocol switch method (about an even split
prior to this commit).
This completes an architectural change that was begun in 1996 to permit
protocols to provide substitute implementations, as now used by UDP.
Consumers now uniformly invoke sosend(), soreceive(), and sopoll() to
perform these operations on sockets -- in particular, distributed file
systems and socket system calls.
Architectural head nod: sam, gnn, wollman
the kernel malloc(9) state for vmstat -m. libmemstat is now used to
generate a machine-readable version which is converged by vmstat -m
into a human-readable version.
Not for MFC.
used to mark UNIX domain sockets as being in the process of binding or
connecting. Use these to prevent simultaneous bind or connect
operations by multiple threads or processes on the same socket at the
same time, which closes race conditions present in the UNIX domain
socket implementation since inception.
function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket. pru_abort is now a
notification of close also, and no longer detaches. pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket. This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.
This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree(). With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.
Reviewed by: gnn
that the only remove hook operation that can occur while processing the
hooks is to remove the currently executing hook. This should be safe as
the existing code has assumed this already for a long time now.
Reviewed by: scottl
MFC after: 1 week
don't want to mix process and thread scheduling options together in these
functions, now the thread scheduling option is implemented in new thr
syscalls.
these syscalls are designed to set thread's scheduling parameters and
policy, because each syscall contains a size parameter, it is possible
to support future scheduling option, e.g SCHED_SPORADIC, this option
needs other fields in structure sched_param, current they are not
avaiblable.
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer). So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt. Also, now that it's easy to do so,
enable paging by default for all ddb commands. Any command that wishes to
honor the quit flag can do so by checking db_pager_quit. Note that the
pager can also be effectively disabled by setting $lines to 0.
Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
terminates early.
- 'show intr' now actually checks the quit flag and terminates early.
SCHED_OTHER, the same range as rtprio() is using. In old code,
it returns nice range -20 .. 20, nice should be treated as process
weight, it is really managed by getpriority() and setpriority()
syscalls, they are different.
using sorele() and the full tear-down path. Since protocol state
allocation failed, this is not required (and is arguably undesirable).
This matches the behavior of sonewconn() under the same circumstances.
locks and the unplock during uipc_rcvd() and uipc_send() by caching
certain values from one structure while its locks are held, and
applying them to a second structure while its locks are held. If
done carefully, this should be correct, and will reduce the amount
of work done with the global unp lock held.
Tested by: kris (earlier version)
ibcs2_getdents(), ibcs2_read(), ogetdirentries(), svr4_sys_getdents(),
and svr4_sys_getdents64() similar to that in getdirentries().
- Mark ibcs2_getdents(), ibcs2_read(), linux_getdents(), linux_getdents64(),
linux_readdir(), ogetdirentries(), svr4_sys_getdents(), and
svr4_sys_getdents64() MPSAFE.
done this in ptrace syscall, when a pid is large than PID_MAX, the syscall
will search a thread in current process. It permits 1:1 thread library to
get and set a thread's scheduler attributes.
unless current thread is realtime thread, in such case, we set a new zero
priority for it, notice we don't have per-thread nice, the priority
passed by userland is ignored here.
use by ABI emulators.
- Alter the interface of kern_recvit() somewhat. Specifically, go ahead
and hard code UIO_USERSPACE in the uio as that's what all the callers
specify. In place, add a new uioseg to indicate what type of pointer
is in mp->msg_name. Previously it was always a userland address, but
ABI emulators may pass in kernel-side sockaddrs. Also, remove the
namelenp field and instead require the two places that used it to
explicitly copy mp->msg_namelen out to userland.
- Use the patched kern_recvit() to replace svr4_recvit() and the stock
kern_sendit() to replace svr4_sendit().
- Use kern_bind() instead of stackgap use in ti_bind().
- Use kern_getpeername() and kern_getsockname() instead of stackgap in
svr4_stream_ti_ioctl().
- Use kern_connect() instead of stackgap in svr4_do_putmsg().
- Use kern_getpeername() and kern_accept() instead of stackgap in
svr4_do_getmsg().
- Retire the stackgap from SVR4 compat as it is no longer used.
that the 'data' pointer is already setup to point to a valid KVM buffer
or contains the copied-in data from userland as appropriate (ioctl(2)
still does this). kern_ioctl() takes care of looking up a file pointer,
implementing FIONCLEX and FIOCLEX, and calling fi_ioctl().
- Use kern_ioctl() to implement xenix_rdchk() instead of using the stackgap
and mark xenix_rdchk() MPSAFE.
mostly consists of pushing a few copyin's and copyout's up into
__semctl() as all the other callers were already doing the UIO_SYSSPACE
case. This also changes kern_semctl() to set the return value in a passed
in pointer to a register_t rather than td->td_retval[0] directly so that
callers can only set td->td_retval[0] if all the various copyout's succeed.
As a result of these changes, kern_semctl() no longer does copyin/copyout
(except for GETALL/SETALL) so simplify the locking to acquire the semakptr
mutex before the MAC check and hold it all the way until the end of the
big switch statement. The GETALL/SETALL cases have to temporarily drop it
while they do copyin/malloc and copyout. Also, simplify the SETALL case to
remove handling for a non-existent race condition.
to use the hinted child system. Bus drivers that use this need to
implmenet the bus_hinted_child method, where they actually add the
child to their bus, as they see fit. The bus is repsonsible for
getting the attribtues for the child, adding it in the right order,
etc. ISA hinting will be updated to use this method.
MFC After: 3 days
subr_acl_posix1e.c, leaving kern_acl.c containing only ACL system
calls and utility routines common across ACL types.
Add subr_acl_posix1e.c to the build.
Obtained from: TrustedBSD Project
not all known to be MPSAFE yet.
- Actually remove Giant from the kernel linker by taking it out of the
KLD_LOCK() and KLD_UNLOCK() macros.
Pointy hat to: jhb (2)
ibcs2_[gs]etgroups() rather than using the stackgap. This also makes
ibcs2_[gs]etgroups() MPSAFE. Also, it cleans up one bit of weirdness in
the old setgroups() where it allocated an entire credential just so it had
a place to copy the group list into. Now setgroups just allocates a
NGROUPS_MAX array on the stack that it copies into and then passes to
kern_setgroups().
a local 'semid' variable which was the array index and used uap->semid
as the original IPC id. During the kern_semctl() conversion those two
variables were collapsed into a single 'semid' variable breaking the
places that needed the original IPC ID. To fix, add a new 'semidx'
variable to hold the array index and leave 'semid' unmolested as the IPC
id. While I'm here, explicitly document that the (undocumented, at least
in semctl(2)) SEM_STAT command curiously expects an array index in the
'semid' parameter rather than an IPC id.
Submitted by: maxim
to a copied-in copy of the 'union semun' and a uioseg to indicate which
memory space the 'buf' pointer of the union points to. This is then used
in linux_semctl() and svr4_sys_semctl() to eliminate use of the stackgap.
- Mark linux_ipc() and svr4_sys_semsys() MPSAFE.
from going away. mount(2) is now MPSAFE.
- Expand the scope of Giant some in unmount(2) to protect the mp structure
(or rather, to handle concurrent unmount races) from going away.
umount(2) is now MPSAFE, as well as linux_umount() and linux_oldumount().
- nmount(2) and linux_mount() were already MPSAFE.
- For privileged processes safe two mutex operations.
We may want to consider if this is good idea to use SUSER_ALLOWJAIL here,
but for now I didn't wanted to change the original behaviour.
Reviewed by: rwatson
all of the module event handlers are MP safe yet, so always acquire Giant
for now when invoking module event handlers. Eventually we can add an
MPSAFE flag or some such and add appropriate locking to all module event
handlers.
in 1999, and there are changes to the sysctl names compared to PR,
according to that discussion. The description is in sys/conf/NOTES.
Lines in the GENERIC files are added in commented-out form.
I'll attach the test script I've used to PR.
PR: kern/14584
Submitted by: babkin
protect all linker-related data structures including the contents of
linker file objects and the any linker class data as well. Considering how
rarely the linker is used I just went with the simple solution of
single-threading the whole thing rather than expending a lot of effor on
something more fine-grained and complex. Giant is still explicitly
acquired while registering and deregistering sysctl's as well as in the
elf linker class while calling kmupetext(). The rest of the linker runs
without Giant unless it has to acquire Giant while loading files from a
non-MPSAFE filesystem.
- Add a new function linker_release_module() as a more intuitive complement
to linker_reference_module() that wraps linker_file_unload().
linker_release_module() can either take the module name and version info
passed to linker_reference_module() or it can accept the linker file
object returned by linker_reference_module().
file objects calling a user-specified predicate function on each object.
The iteration terminates either when the entire list has been iterated
over or the predicate function returns a non-zero value.
linker_file_foreach() returns the value returned by the last invocation
of the predicate function. It also accepts a void * context pointer that
is passed to the predicate function as well. Using an iterator function
avoids exposing linker internals to the rest of the kernel making locking
simpler.
- Use linker_file_foreach() instead of walking the list of linker files
manually to lookup ndis files in ndis(4).
- Use linker_file_foreach() to implement linker_hwpmc_list_objects().
in setsockopt so that they can be compared correctly against negative
values. Passing in a negative value had a rather negative effect
on our socket code, making it impossible to open new sockets.
PR: 98858
Submitted by: James.Juran@baesystems.com
MFC after: 1 week
It is similar to debug.kdb.trap, except for it tries to cause a page fault
via a call to an invalid pointer. This can highlight differences between
a fault on data access vs. a fault on code call some CPUs might have.
This appeared as a test for a work \
Sponsored by: RiNet (Cronyx Plus LLC)
basically always violated) invariannts of soreceive(), which assume
that the first mbuf pointer in a receive socket buffer can't change
while the SB_LOCK sleepable lock is held on the socket buffer,
which is precisely what these functions do. No current protocols
invoke these functions, and removing them will help discourage them
from ever being used. I should have removed them years ago, but
lost track of it.
MFC after: 1 week
Prodded almost by accident by: peter
frequency, quality and current value of each available time counter.
At the moment all of these are read-only, but it might make sense to
make some of these read-write in the future.
MFC after: 3 months
filesystem agnostic. We are not touching any file system specific functions
in this code path. Since we have a cache lock, there is really no need to
keep Giant around here.
This eliminates Giant acquisitions for any syscall which is auditing pathnames.
Discussed with: jeff
yield() and sched_yield() syscalls. Every scheduler has its own way
to relinquish cpu, the ULE and CORE schedulers have two internal run-
queues, a timesharing thread which calls yield() syscall should be
moved to inactive queue.
KASSERT(ke->ke_runq == NULL) panic when the sched_add is recursively
called by maybe_preempt.
Reported by: Wojciech A. Koszek < dunstan at freebsd dot czest dot pl >
we intend for the user to be able to unload them later via kldunload(2)
instead of calling linker_load_module() and then directly adjusting the
ref count on the linker file structure. This makes the resulting
consumer code simpler and cleaner and better hides the linker internals
making it possible to sanely lock the linker.
Giant down in it.
- Push Giant down in kern_kldunload() and reorganize it slightly to avoid
using gotos. Also, expose this function to the rest of the kernel.
- Use a 'struct kld_file_stat' on the stack to read data under the lock
and then do one copyout() w/o holding the lock at the end to push the
data out to userland.
linker_file_unload() instead of in the middle of a bunch of code for
the case of dropping the last reference to improve readability and sanity.
While I'm here, remove pointless goto's that were just jumping to a
return statement.
sockets:
1) A sender sends SCM_CREDS message to a reciever, struct cmsgcred;
2) A reciever sets LOCAL_CREDS socket option and gets sender
credentials in control message, struct sockcred.
Both methods use the same control message type SCM_CREDS with the
same control message level SOL_SOCKET, so they are indistinguishable
for the receiver. A difference in struct cmsgcred and struct sockcred
layouts may lead to unwanted effects.
Now for sockets with LOCAL_CREDS option remove all previous linked
SCM_CREDS control messages and then add a control message with
struct sockcred so the process specifically asked for the peer
credentials by LOCAL_CREDS option always gets struct sockcred.
PR: kern/90800
Submitted by: Andrey Simonenko
Regres. tests: tools/regression/sockets/unix_cmsg/
MFC after: 1 month
I picked it up again. The scheduler is forked from ULE, but the
algorithm to detect an interactive process is almost completely
different with ULE, it comes from Linux paper "Understanding the
Linux 2.6.8.1 CPU Scheduler", although I still use same word
"score" as a priority boost in ULE scheduler.
Briefly, the scheduler has following characteristic:
1. Timesharing process's nice value is seriously respected,
timeslice and interaction detecting algorithm are based
on nice value.
2. per-cpu scheduling queue and load balancing.
3. O(1) scheduling.
4. Some cpu affinity code in wakeup path.
5. Support POSIX SCHED_FIFO and SCHED_RR.
Unlike scheduler 4BSD and ULE which using fuzzy RQ_PPQ, the scheduler
uses 256 priority queues. Unlike ULE which using pull and push, the
scheduelr uses pull method, the main reason is to let relative idle
cpu do the work, but current the whole scheduler is protected by the
big sched_lock, so the benefit is not visible, it really can be worse
than nothing because all other cpu are locked out when we are doing
balancing work, which the 4BSD scheduelr does not have this problem.
The scheduler does not support hyperthreading very well, in fact,
the scheduler does not make the difference between physical CPU and
logical CPU, this should be improved in feature. The scheduler has
priority inversion problem on MP machine, it is not good for
realtime scheduling, it can cause realtime process starving.
As a result, it seems the MySQL super-smack runs better on my
Pentium-D machine when using libthr, despite on UP or SMP kernel.
with firmware_unregister(). Previously when the last driver reference
had been dropped we would clear the list entry under the assumption
that the firmware module was about to be unloaded, but this was not
true if the firmware image had been loaded manually with kldload.
This makes it possible to manually kldload firmware images as a
workaround for drivers such as ipw that attempt to load firmware
while resuming after a suspend.
Reviewed by: mlaier (an earlier version of the patch)
- Move sonewconn(), which creates new sockets for incoming connections on
listen sockets, so that all socket allocate code is together in
uipc_socket.c.
- Move 'maxsockets' and associated sysctls to uipc_socket.c with the
socket allocation code.
- Move kern.ipc sysctl node to uipc_socket.c, add a SYSCTL_DECL() for it
to sysctl.h and remove lots of scattered implementations in various
IPC modules.
- Sort sodealloc() after soalloc() in uipc_socket.c for dependency order
reasons. Statisticize soalloc() and sodealloc() as they are now
required only in uipc_socket.c, and are internal to the socket
implementation.
After this change, socket allocation and deallocation is entirely
centralized in one file, and uipc_socket2.c consists entirely of socket
buffer manipulation and default protocol switch functions.
MFC after: 1 month
non-intuitive for the ~ to be built into the mask. All the users now
explicitly ~ the mask. In addition, add MTX_UNOWNED to the mask even
though it technically isn't a flag. This should unbreak mtx_owner().
Quickly spotted by: kris
forget to unbusy file system before its destruction.
This fixes the following warning on mount failure:
Mount point <X> had 1 dangling refs
Tested by: wkoszek
a) were incorrectly written and therefore never compiled into
assertions, and
b) were incorrectly specified and when compiled resulted in a
failed assertion.
vmspace_exitfree() and vmspace_free() which could result in the same
vmspace being freed twice.
Factor out part of exit1() into new function vmspace_exit(). Attach
to vmspace0 to allow old vmspace to be freed earlier.
Add new function, vmspace_acquire_ref(), for obtaining a vmspace
reference for a vmspace belonging to another process. Avoid changing
vmspace refcount from 0 to 1 since that could also lead to the same
vmspace being freed twice.
Change vmtotal() and swapout_procs() to use vmspace_acquire_ref().
Reviewed by: alc
lookup, rename, strategy, islocked
The missing % sign meant that the lines were processed as plain
comments and the corresponding assertions were never generated.
This used to make syscons switch to vty0 when we entered DDB but this
was lost in the KDB shuffle. We may want to bring it back down the road
but it should be done by calling cn_init_t/cn_term_t instead, possibly
with a flag argument saying "Debugger!"
