back into the calling MD code. The MD code must ensure no races between
checking the astpening flag and returning to usermode.
Submitted by: peter (ia64 bits)
Tested on: alpha (peter, jeff), i386, ia64 (peter), sparc64
in vfs_mount(), in particular revisions 1.215, 1.227 and 1.240.
- flag2 is a low quality variable name, change it to kern_flag.
- strncpy NUL-terminates f_fstypename and f_mntonname since the strings
have length <= <buffer length> - 1, so the explicit NUL-termination is
bogus.
- M_ZERO'ing space for fstype and fspath is stupid since we never use the
space beyond the end of the string.
- Do various style(9) cleanups in both functions.
Submitted by: bde
Reviewed by: phk
can be called both with and without the pipe mutex held. (For example,
if called by pipeselwakeup(), it is held. Whereas, if called by kqueue_scan(),
it is not.)
Reviewed by: alfred
There is still some locations where the PROC lock should be held
in order to prevent inconsistent views from outside (like the
proc->p_fd fix for kern/vfs_syscalls.c:checkdirs()) that can be
fixed later.
Submitted by: Jonathan Mini <mini@haikugeek.com>
with this flag. Remove the dup_list and dup_ok code from subr_witness. Now
we just check for the flag instead of doing string compares.
Also, switch the process lock, process group lock, and uma per cpu locks over
to this interface. The original mechanism did not work well for uma because
per cpu lock names are unique to each zone.
Approved by: jhb
disablement assumptions in kern_fork.c by adding another API call,
cpu_critical_fork_exit(). Cleanup the td_savecrit field by moving it
from MI to MD. Temporarily move cpu_critical*() from <arch>/include/cpufunc.h
to <arch>/<arch>/critical.c (stage-2 will clean this up).
Implement interrupt deferral for i386 that allows interrupts to remain
enabled inside critical sections. This also fixes an IPI interlock bug,
and requires uses of icu_lock to be enclosed in a true interrupt disablement.
This is the stage-1 commit. Stage-2 will occur after stage-1 has stabilized,
and will move cpu_critical*() into its own header file(s) + other things.
This commit may break non-i386 architectures in trivial ways. This should
be temporary.
Reviewed by: core
Approved by: core
- return error -> return (error);
- move a declaration to the top of the function.
- become bug for bug compatible with if (error) lines.
Submitted by: bde
new vfs_getopt()/vfs_copyopt() API. This is intended to be used
later, when there will be filesystems implementing the VFS_NMOUNT
operation. The mount(2) system call will disappear when all
filesystems will be converted to the new API. Documentation will
be committed in a while.
Reviewed by: phk
modules (ie. procfs.ko).
When the kernel loads dynamic filesystem module, it looks for any of the
VOP operations specified by the new filesystem that have not been registered
already by the currently known filesystems. If any of such operations exist,
vfs_add_vnops function calls vfs_opv_recalc function, which rebuilds vop_t
vectors for each filesystem and sets all global pointers like ufs_vnops_p,
devfs_specop_p, etc to the new values and then frees the old pointers. This
behavior is bad because there might be already active vnodes whose v_op fields
will be left pointing to the random garbage, leading to inevitable crash soon.
Submitted by: Alexander Kabaev <ak03@gte.com>
kern_linker.c and rev. 1.237 of vfs_syscalls.c since these are not the
source of the recent panics occuring around kldloading file system
support modules.
Requested by: rwatson
not removing tabs before "__P((", and not outdenting continuation lines
to preserve non-KNF lining up of code with parentheses. Switch to KNF
formatting and/or rewrap the whole prototype in some cases.
code that is still not safe. suser() reads p_ucred so it still needs
Giant for the time being. This should allow kern.giant.proc to be set
to 0 for the time being.
Move the network code from using cr_cansee() to check whether a
socket is visible to a requesting credential to using a new
function, cr_canseesocket(), which accepts a subject credential
and object socket. Implement cr_canseesocket() so that it does a
prison check, a uid check, and add a comment where shortly a MAC
hook will go. This will allow MAC policies to seperately
instrument the visibility of sockets from the visibility of
processes.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
to test req->td for NULL values and then do somewhat more bizarre things
relating to securelevel special-casing and suser checks. Remove the
testing and conditional security checks based on req->td!=NULL, and insert
a KASSERT that td != NULL. Callers to sysctl must always specify the
thread (be it kernel or otherwise) requesting the operation, or a
number of current sysctls will fail due to assumptions that the thread
exists.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
Discussed with: bde
NULL, turn warning printf's into panic's, since this call has been
restructured such that a NULL cred would result in a page fault anyway.
There appears to be one case where NULL is explicitly passed in in the
sysctl code, and this is believed to be in error, so will be modified.
Securelevels now always require a credential context so that per-jail
securelevels are properly implemented.
Obtained from: TrustedBSD Project
Sponsored by: NAI Labs
Discussed with: bde
made aware in jail environments. Supposedly something is broken, so
this should be backed out until further investigation proves otherwise,
or a proper fix can be provided.
method-based inter-process security checks. To do this, introduce
a new cr_seeotheruids(u1, u2) function, which encapsulates the
"see_other_uids" logic. Call out to this policy following the
jail security check for all of {debug,sched,see,signal} inter-process
checks. This more consistently enforces the check, and makes the
check easy to modify. Eventually, it may be that this check should
become a MAC policy, loaded via a module.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
Instead of caching the ucred reference, just go ahead and eat the
decerement and increment of the refcount. Now that Giant is pushed down
into crfree(), we no longer have to get Giant in the common case. In the
case when we are actually free'ing the ucred, we would normally free it on
the next kernel entry, so the cost there is not new, just in a different
place. This also removse td_cache_ucred from struct thread. This is
still only done #ifdef DIAGNOSTIC.
[ missed this file in the previous commit ]
Tested on: i386, alpha
- Add a cred_free_thread() function (conditional on DIAGNOSTICS) that drops
a per-thread ucred reference to be used in debugging code when leaving
the kernel.
against users within a jail attempting to load kernel modules.
- Add a check of securelevel_gt() to vfs_mount() in order to chop some
low hanging fruit for the repair of securelevel checking of linking and
unlinking files from within jails. There is more to be done here.
Reviewed by: rwatson
all the global bits of ``module'' data. This commit adds a few generic
macros, MOD_SLOCK, MOD_XLOCK, etc., that are meant to be used as ways
of accessing the SX lock. It is also the first step in helping to lock
down the kernel linker and module systems.
Reviewed by: jhb, jake, smp@
locking flags when acquiring a vnode. The immediate purpose is
to allow polling lock requests (LK_NOWAIT) needed by soft updates
to avoid deadlock when enlisting other processes to help with
the background cleanup. For the future it will allow the use of
shared locks for read access to vnodes. This change touches a
lot of files as it affects most filesystems within the system.
It has been well tested on FFS, loopback, and CD-ROM filesystems.
only lightly on the others, so if you find a problem there, please
let me (mckusick@mckusick.com) know.
pmap_qremove. pmap_kenter is not safe to use in MI code because it is not
guaranteed to flush the mapping from the tlb on all cpus. If the process
in question is preempted and migrates cpus between the call to pmap_kenter
and pmap_kremove, the original cpu will be left with stale mappings in its
tlb. This is currently not a problem for i386 because we do not use PG_G on
SMP, and thus all mappings are flushed from the tlb on context switches, not
just user mappings. This is not the case on all architectures, and if PG_G
is to be used with SMP on i386 it will be a problem. This was committed by
peter earlier as part of his fine grained tlb shootdown work for i386, which
was backed out for other reasons.
Reviewed by: peter
the bio and buffer structures to have daddr64_t bio_pblkno,
b_blkno, and b_lblkno fields which allows access to disks
larger than a Terabyte in size. This change also requires
that the VOP_BMAP vnode operation accept and return daddr64_t
blocks. This delta should not affect system operation in
any way. It merely sets up the necessary interfaces to allow
the development of disk drivers that work with these larger
disk block addresses. It also allows for the development of
UFS2 which will use 64-bit block addresses.
kern/kern_descrip.c:
Aquire Giant in fdrop_locked when file refcount hits zero, this removes
the requirement for the caller to own Giant for the most part.
kern/kern_ktrace.c:
Aquire Giant in ktrgenio, simplifies locking in upper read/write syscalls.
kern/vfs_bio.c:
Aquire Giant in bwillwrite if needed.
kern/sys_generic.c
Giant pushdown, remove Giant for:
read, pread, write and pwrite.
readv and writev aren't done yet because of the possible malloc calls
for iov to uio processing.
kern/sys_socket.c
Grab giant in the socket fo_read/write functions.
kern/vfs_vnops.c
Grab giant in the vnode fo_read/write functions.
Missed a place where the pipe sleep lock was needed in order to safely grab
Giant, fix it and add an assertion to make sure this doesn't happen again.
Fix typos in the PIPE_GET_GIANT/PIPE_DROP_GIANT that could cause the
wrong mutex to get passed to PIPE_LOCK/PIPE_UNLOCK.
Fix a location where the wrong pipe was being passed to
PIPE_GET_GIANT/PIPE_DROP_GIANT.
Problem:
selwakeup required calling pfind which would cause lock order
reversals with the allproc_lock and the per-process filedesc lock.
Solution:
Instead of recording the pid of the select()'ing process into the
selinfo structure, actually record a pointer to the thread. To
avoid dereferencing a bad address all the selinfo structures that
are in use by a thread are kept in a list hung off the thread
(protected by sellock). When a selwakeup occurs the selinfo is
removed from that threads list, it is also removed on the way out
of select or poll where the thread will traverse its list removing
all the selinfos from its own list.
Problem:
Previously the PROC_LOCK was used to provide the mutual exclusion
needed to ensure proper locking, this couldn't work because there
was a single condvar used for select and poll and condvars can
only be used with a single mutex.
Solution:
Introduce a global mutex 'sellock' which is used to provide mutual
exclusion when recording events to wait on as well as performing
notification when an event occurs.
Interesting note:
schedlock is required to manipulate the per-thread TDF_SELECT
flag, however if given its own field it would not need schedlock,
also because TDF_SELECT is only manipulated under sellock one
doesn't actually use schedlock for syncronization, only to protect
against corruption.
Proc locks are no longer used in select/poll.
Portions contributed by: davidc
While doing this, move it earlier in the sysinit boot process so that the
VM system can use it.
After that, the system is now able to use sx locks instead of lockmgr
locks in the VM system. To accomplish this, some of the more
questionable uses of the locks (such as testing whether they are
owned or not, as well as allowing shared+exclusive recursion) are
removed, and simpler logic throughout is used so locks should also be
easier to understand.
This has been tested on my laptop for months, and has not shown any
problems on SMP systems, either, so appears quite safe. One more
user of lockmgr down, many more to go :)
The stat() and open() calls have been changed to make use of this new functionality. Using shared locks in
these cases is sufficient and can significantly reduce their latency if IO is pending to these vnodes. Also,
this reduces the number of exclusive locks that are floating around in the system, which helps reduce the
number of deadlocks that occur.
A new kernel option "LOOKUP_SHARED" has been added. It defaults to off so this patch can be turned on for
testing, and should eventually go away once it is proven to be stable. I have personally been running this
patch for over a year now, so it is believed to be fully stable.
Reviewed by: jake, obrien
Approved by: jake
in "missing dependencies" error when loading some kld modules. It is sad to
see how often these days style cleanus break doesn't broken things. Perhaps
people should recall good old principle: "don't fix it if it isn't broken".
fully instaniated.
Revert the logic in pipeclose so that we don't have the entire function
pretty much under a single if() statement, instead invert the test and
just return if it fails.
Submitted (in different form) by: bde
Don't use pool mutexes for pipes. We can not use pool mutexes
because we will need to grab the select lock while holding a pipe
lock which is not allowed because you may not aquire additional
mutexes when holding a pool mutex.
Instead malloc(9) space for the mutex that is shared between the
pipes.
simply need to prevent switching from another CPU and do not need
interrupts disabled.
- Add a comment to witness_list() about why displaying spin locks for
threads on other CPU's really is just a bad idea and probably shouldn't
be done.
to exhaust all kmaps. The only reward for setting maxproc
to a value which will cause kmap exhaustion is a panic
during a forkbomb attack.
MFC after: 3 days
- Move jail checks and some other checks involving constants and stack
variables out from under Giant. This isn't perfectly safe atm because
jail_sysvipc_allowed is read w/o a lock meaning that its value could be
stale. This global variable will soon become a per-jail flag, however,
at which time it will either not need a lock or will use the prison lock.
people working on the MAC tree from getting toasted whenever system call
numbers are allocated in the main tree (for example, for KSE :-).
Calls allocated: __mac_{get,set}_proc, __mac_{get,set}_{fd,file}().
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
Includes some minor whitespace changes, and re-ordering to be able to document
properly (e.g, grouping of variables and the SYSCTL macro calls for them, where
the documentation has been added.)
Reviewed by: phk (but all errors are mine)
be allocated as arrays indexed by the cpu id. Previously the only reliable
way to know the max cpu id was through MAXCPU. mp_ncpus isn't useful here
because cpu ids may be sparsely mapped, although x86 and alpha do not do this.
Also, call cpu_mp_probe much earlier so the max cpu id is known before the VM
starts up. This is intended to help support per cpu queues for the new
allocator, but may be useful elsewhere.
Reviewed by: jake
Approved by: jake
This makes other power-management system (APM for now) to be able to
generate power profile change events (ie. AC-line status changes), and
other kernel components, not only the ACPI components, can be notified
the events.
- move subroutines in acpi_powerprofile.c (removed) to kern/subr_power.c
- call power_profile_set_state() also from APM driver when AC-line
status changes
- add call-back function for Crusoe LongRun controlling on power
profile changes for a example
PAGE_SIZE / MCLBYTES == 1 crash. Fix them by changing the
appropriate "allocate new page and bucket" code in mb_alloc to use
the macro for properly grabbing an allocated object from a bucket,
the one that checks whether the bucket is empty.
This should allow ken to continue testing zero-copy stuff on -CURRENT.
Noticed and provided debug info: ken
fill out netc_anon (a `struct ucred'), and add an XXX around the
entire operation since it isn't clear whether it's doing the right
thing with things like cr_uidinfo and cr_prison.
the data was supplied as a uio or an mbuf. Previously the limit was
ignored for mbuf data, and NFS could run the kernel out of mbufs
when an ipfw rule blocked retransmissions.
