fsyncs, which typically occur during unmounting, will drain all dirty
buffers even if it takes multiple passes to do so. The guarentee was
mangled by the last patch which solved a problem due to -current disabling
interrupts while holding giant (which caused an infinite spin loop waiting for
I/O to complete). -stable does not have either patch, but has a similar
bug in the original spec_fsync() code which is triggered by a bug in the
softupdates umount code, a fix for which will be committed to -current
as soon as Kirk stamps it. Then both solutions will be MFC'd to -stable.
-stable currently suffers from a combination of the softupdates bug and
a small window of opportunity in the original spec_fsync() code, and -stable
also suffers from the spin-loop bug but since interrupts are enabled the
spin resolves itself in a few milliseconds.
in 4.2-REL which I ripped out in -stable and -current when implementing the
low-memory handling solution. However, maxlaunder turns out to be the saving
grace in certain very heavily loaded systems (e.g. newsreader box). The new
algorithm limits the number of pages laundered in the first pageout daemon
pass. If that is not sufficient then suceessive will be run without any
limit.
Write I/O is now pipelined using two sysctls, vfs.lorunningspace and
vfs.hirunningspace. This prevents excessive buffered writes in the
disk queues which cause long (multi-second) delays for reads. It leads
to more stable (less jerky) and generally faster I/O streaming to disk
by allowing required read ops (e.g. for indirect blocks and such) to occur
without interrupting the write stream, amoung other things.
NOTE: eventually, filesystem write I/O pipelining needs to be done on a
per-device basis. At the moment it is globalized.
of explicit calls to lockmgr. Also provides macros for the flags
pased to specify shared, exclusive or release which map to the
lockmgr flags. This is so that the use of lockmgr can be easily
replaced with optimized reader-writer locks.
- Add some locking that I missed the first time.
Don't check for a null pointer if malloc called with M_WAITOK.
Submitted by: josh@zipperup.org
Submitted by: Robert Drehmel <robd@gmx.net>
Approved by: bp
<sys/proc.h> to <sys/systm.h>.
Correctly document the #includes needed in the manpage.
Add one now needed #include of <sys/systm.h>.
Remove the consequent 48 unused #includes of <sys/proc.h>.
the offending inline function (BUF_KERNPROC) on it being #included
already.
I'm not sure BUF_KERNPROC() is even the right thing to do or in the
right place or implemented the right way (inline vs normal function).
Remove consequently unneeded #includes of <sys/proc.h>
file types to requiring all file types to properly implement fo_stat.
This makes any new file type additions much easier as this code no
longer has to be modified to accomodate it.
o Instead of using curproc in fdesc_allocvp, pass a `struct proc' pointer as
a new fifth parameter.
cheap to setup that it doesn't really matter that we recycle device
vnodes at kleenex speed.
Implement first cut try at killing cloned devices when they are
not needed anymore. For now only the bpf driver is involved in
this experiment. Cloned devices can set the SI_CHEAPCLONE flag
which allows us to destroy_dev() it when the vcount() drops to zero
and the vnode is reclaimed. For now it's a requirement that the
driver doesn't keep persistent state from close to (re)open.
Some whitespace changes.
-- don't depend on garbage in <sys/mount.h>. mbufs aren't actually
used here either. They should have been completely removed from filesystem
interfaces when they were removed from the interfaces to convert between
file handles and vnodes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
Replace shared lock on vnode with exclusive one. It shouldn't impact
perfomance as NCP protocol doesn't support outstanding requests.
Do not hold simple lock on vnode for long period of time.
Add functionality to the nwfs_print() routine.
Add correct support for v_object management, so mmap() operation should
work properly.
Add support for extattrctl() routine (submitted by semenu).
At this point nullfs can be considered as functional and much more stable.
In fact, it should behave as a "hard" "symlink" to underlying filesystem.
Reviewed in general by: mckusick, dillon
Parts of logic obtained from: NetBSD
include:
* Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The
alpha port is still in transition and currently uses both.)
* Per-CPU idle processes.
* Interrupts are run in their own separate kernel threads and can be
preempted (i386 only).
Partially contributed by: BSDi (BSD/OS)
Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
to recycle inodes after a destroy_dev() but not until all mounts
have picked up the change.
Add support for an overflow table for DEVFS inodes. The static
table defaults to 1024 inodes, if that fills, an overflow table
of 32k inodes is allocated. Both numbers can be changed at
compile time, the size of the overflow table also with the
sysctl vfs.devfs.noverflow.
Use atomic instructions to barrier between make_dev()/destroy_dev()
and the mounts.
Add lockmgr() locking of directories for operations accessing or
modifying the directory TAILQs.
Various nitpicking here and there.
at this point):
Replace all '#ifdef DEBUG' with '#ifdef NULLFS_DEBUG' and add NULLFSDEBUG
macro.
Protect nullfs hash table with lockmgr.
Use proper order of operations when freeing mnt_data.
Return correct fsid in the null_getattr().
Add null_open() function to catch MNT_NODEV (obtained from NetBSD).
Add null_rename() to catch cross-fs rename operations (submitted by
Ustimenko Semen <semen@iclub.nsu.ru>)
Remove duplicate $FreeBSD$ tags.
cloning infrastructure standard in kern_conf. Modules are now
the same with or without devfs support.
If you need to detect if devfs is present, in modules or elsewhere,
check the integer variable "devfs_present".
This happily removes an ugly hack from kern/vfs_conf.c.
This forces a rename of the eventhandler and the standard clone
helper function.
Include <sys/eventhandler.h> in <sys/conf.h>: it's a helper #include
like <sys/queue.h>
Remove all #includes of opt_devfs.h they no longer matter.
rather than implementing its own {uid,gid,other} checks against vnode
mode. Similar change to linprocfs currently under review.
Obtained from: TrustedBSD Project
int p_can(p1, p2, operation, privused)
which allows specification of subject process, object process,
inter-process operation, and an optional call-by-reference privused
flag, allowing the caller to determine if privilege was required
for the call to succeed. This allows jail, kern.ps_showallprocs and
regular credential-based interaction checks to occur in one block of
code. Possible operations are P_CAN_SEE, P_CAN_SCHED, P_CAN_KILL,
and P_CAN_DEBUG. p_can currently breaks out as a wrapper to a
series of static function checks in kern_prot, which should not
be invoked directly.
o Commented out capabilities entries are included for some checks.
o Update most inter-process authorization to make use of p_can() instead
of manual checks, PRISON_CHECK(), P_TRESPASS(), and
kern.ps_showallprocs.
o Modify suser{,_xxx} to use const arguments, as it no longer modifies
process flags due to the disabling of ASU.
o Modify some checks/errors in procfs so that ENOENT is returned instead
of ESRCH, further improving concealment of processes that should not
be visible to other processes. Also introduce new access checks to
improve hiding of processes for procfs_lookup(), procfs_getattr(),
procfs_readdir(). Correct a bug reported by bp concerning not
handling the CREATE case in procfs_lookup(). Remove volatile flag in
procfs that caused apparently spurious qualifier warnigns (approved by
bde).
o Add comment noting that ktrace() has not been updated, as its access
control checks are different from ptrace(), whereas they should
probably be the same. Further discussion should happen on this topic.
Reviewed by: bde, green, phk, freebsd-security, others
Approved by: bde
Obtained from: TrustedBSD Project
object before falling back on privilege. Make vaccess() accept an
additional optional argument, privused, to determine whether
privilege was required for vaccess() to return 0. Add commented
out capability checks for reference. Rename some variables to make
it more clear which modes/uids/etc are associated with the object,
and which with the access mode.
o Update file system use of vaccess() to pass NULL as the optional
privused argument. Once additional patches are applied, suser()
will no longer set ASU, so privused will permit passing of
privilege information up the stack to the caller.
Reviewed by: bde, green, phk, -security, others
Obtained from: TrustedBSD Project
longs larger than 32 bits or strict alignment requirements.
pm_fatmask had type u_long, but it must have a type that has precisely
32 bits and this type must be no smaller than int, so that ~pmp->pm_fatmask
has no bits above the 31st set. Otherwise, comparisons between (cn
| ~pmp->pm_fatmask) and magic 32-bit "cluster" numbers always fail.
The correct fix is to use the C99 type uint_least32_t and mask with
0xffffffff. The quick fix is to use u_int32_t and assume that ints
have
msdosfs metadata is riddled with unaligned fields, and on alphas,
unaligned_fixup() apparently has problems fixing up the unaligned
accesses caused by this. The quick fix is to not comment out the
NetBSD code that sort of handles this, and define UNALIGNED_ACCESS on
i386's so that the code doesn't change on i386's. The correct fix
would define UNALIGNED_ACCESS in a central machine-dependent header
and maybe add some extra cases to unaligned_fixup(). UNALIGNED_ACCESS
is also tested in isofs.
Submitted by: parts by Mark Abene <phiber@radicalmedia.com>
PR: 19086
Implement subdirs.
Build the full "devicename" for cloning functions.
Fix panic when deleted device goes away.
Collaps devfs_dir and devfs_dirent structures.
Add proper cloning to the /dev/fd* "device-"driver.
Fix a bug in make_dev_alias() handling which made aliases appear
multiple times.
Use devfs_clone to implement getdiskbyname()
Make specfs maintain the stat(2) timestamps per dev_t
Remove old DEVFS support fields from dev_t.
Make uid, gid & mode members of dev_t and set them in make_dev().
Use correct uid, gid & mode in make_dev in disk minilayer.
Add support for registering alias names for a dev_t using the
new function make_dev_alias(). These will show up as symlinks
in DEVFS.
Use makedev() rather than make_dev() for MFSs magic devices to prevent
DEVFS from noticing this abuse.
Add a field for DEVFS inode number in dev_t.
Add new DEVFS in fs/devfs.
Add devfs cloning to:
disk minilayer (ie: ad(4), sd(4), cd(4) etc etc)
md(4), tun(4), bpf(4), fd(4)
If DEVFS add -d flag to /sbin/inits args to make it mount devfs.
Add commented out DEVFS to GENERIC
with the new snapshot code.
Update addaliasu to correctly implement the semantics of the old
checkalias function. When a device vnode first comes into existence,
check to see if an anonymous vnode for the same device was created
at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than
creating a new vnode for the device. This corrects a problem which
caused the kernel to panic when taking a snapshot of the root
filesystem.
Change the calling convention of vn_write_suspend_wait() to be the
same as vn_start_write().
Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue when suspending filesystem
operations.
Access to buffers becomes recursive so that snapshots can recursively
traverse their indirect blocks using ffs_copyonwrite() when checking
for the need for copy on write when flushing one of their own indirect
blocks. This eliminates a deadlock between the syncer daemon and a
process taking a snapshot.
Ensure that softdep_process_worklist() can never block because of a
snapshot being taken. This eliminates a problem with buffer starvation.
Cleanup change in ffs_sync() which did not synchronously wait when
MNT_WAIT was specified. The result was an unclean filesystem panic
when doing forcible unmount with heavy filesystem I/O in progress.
Return a zero'ed block when reading a block that was not in use at
the time that a snapshot was taken. Normally, these blocks should
never be read. However, the readahead code will occationally read
them which can cause unexpected behavior.
Clean up the debugging code that ensures that no blocks be written
on a filesystem while it is suspended. Snapshots must explicitly
label the blocks that they are writing during the suspension so that
they do not cause a `write on suspended filesystem' panic.
Reorganize ffs_copyonwrite() to eliminate a deadlock and also to
prevent a race condition that would permit the same block to be
copied twice. This change eliminates an unexpected soft updates
inconsistency in fsck caused by the double allocation.
Use bqrelse rather than brelse for buffers that will be needed
soon again by the snapshot code. This improves snapshot performance.
the gating of system calls that cause modifications to the underlying
filesystem. The gating can be enabled by any filesystem that needs
to consistently suspend operations by adding the vop_stdgetwritemount
to their set of vnops. Once gating is enabled, the function
vfs_write_suspend stops all new write operations to a filesystem,
allows any filesystem modifying system calls already in progress
to complete, then sync's the filesystem to disk and returns. The
function vfs_write_resume allows the suspended write operations to
begin again. Gating is not added by default for all filesystems as
for SMP systems it adds two extra locks to such critical kernel
paths as the write system call. Thus, gating should only be added
as needed.
Details on the use and current status of snapshots in FFS can be
found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness
is not included here. Unless and until you create a snapshot file,
these changes should have no effect on your system (famous last words).
Don't fake any file types, just set vap->va_type to IFTOVT(stb.st_mode).
If something does not report its mode, vap->va_type is set to VNON
accordingly.
using decimal major and minor numbers. "ls -l" reports
disk partitions using decimal major numbers and hex
minor numbers.
make specfs use decimal major numbers and hex minor numbers,
just like "ls -l"
problems when fetch(1) was passed `-o -'. The rationale of this change
is that applications attempting to change underlying vnodes for /dev/fd
nodes are improperly written and the use of this interface should not
ever have been encouraged. Proper alternatives are fchmod, fchown and
others.
PR: 18952
- Remove stale, unused fdescnode->fd_link structure member.
stderr nodes. More specific items of this patch:
o Removed support for symbolic links, and the need for
fdesc_readlink().
o Put all the code from fdesc_attr() into fdesc_getattr() and removed
fdesc_attr(). This also made it easier to properly give all nodes
unique inode numbers.
o The removal of all non-fd nodes allowed the removal of the fdesc_read(),
fdesc_write(), and fdesc_ioctl() nodes, since we no longer have nodes
that get special handling.
o Correct the component name validity-checking in fdesc_lookup(). It
previously detected the end of the string by checking for a terminating
NUL, now it uses cnp->cn_namelen.
o Handle kqueue files as FIFOs. This is probably the closest file type
to represent this type of file there is, and it is unfortunately not
very representative of a kqueue. Creation time is not supported by
kqueue, so ctime, mtime and atime are all set to the current time when
getattr() was called.
o Also set st_[mca]time to the current time since there's no data in
socket structures that can be used to fill this in (FIFOs).
o Simplify fdesc_readdir() since it only has to report the numbered
fd nodes. Add `.' and `..' directory links as well.
o Remove read bits from directories as they tend to confuse programs
like tar(1).
Reviewed by: phk
Discussed with: bde (earlier on, not quite review)
<sys/bio.h>.
<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.
Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.
Still a few bogus uses of struct buf to track down.
Repocopy by: peter
ioccom.h defines only implementation detail, and should therefore
only be included from the #include which defines the ioctl tags,
in other words: never include it from *.c
There's no excuse to have code in synthetic filestores that allows direct
references to the textvp anymore.
Feature requested by: msmith
Feature agreed to by: warner
Move requested by: phk
Move agreed to by: bde
Exceptions:
Vinum untouched. This means that it cannot be compiled.
Greg Lehey is on the case.
CCD not converted yet, casts to struct buf (still safe)
atapi-cd casts to struct buf to examine B_PHYS
(name, value) pairs to be associated with inodes. This support is
used for ACLs, MAC labels, and Capabilities in the TrustedBSD
security extensions, which are currently under development.
In this implementation, attributes are backed to data vnodes in the
style of the quota support in FFS. Support for FFS extended
attributes may be enabled using the FFS_EXTATTR kernel option
(disabled by default). Userland utilities and man pages will be
committed in the next batch. VFS interfaces and man pages have
been in the repo since 4.0-RELEASE and are unchanged.
o ufs/ufs/extattr.h: UFS-specific extattr defines
o ufs/ufs/ufs_extattr.c: bulk of support routines
o ufs/{ufs,ffs,mfs}/*.[ch]: hooks and extattr.h includes
o contrib/softupdates/ffs_softdep.c: extattr.h includes
o conf/options, conf/files, i386/conf/LINT: added FFS_EXTATTR
o coda/coda_vfsops.c: XXX required extattr.h due to ufsmount.h
(This should not be the case, and will be fixed in a future commit)
Currently attributes are not supported in MFS. This will be fixed.
Reviewed by: adrian, bp, freebsd-fs, other unthanked souls
Obtained from: TrustedBSD Project
(Much of this done by script)
Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED.
Move b_pblkno and b_iodone_chain to struct bio while we transition, they
will be obsoleted once bio structs chain/stack.
Add bio_queue field for struct bio aware disksort.
Address a lot of stylistic issues brought up by bde.
fragmentation problem due to geteblk() reserving too much space for the
buffer and imposes a larger granularity (16K) on KVA reservations for
the buffer cache to avoid fragmentation issues. The buffer cache size
calculations have been redone to simplify them (fewer defines, better
comments, less chance of running out of KVA).
The geteblk() fix solves a performance problem that DG was able reproduce.
This patch does not completely fix the KVA fragmentation problems, but
it goes a long way
Mostly Reviewed by: bde and others
Approved by: jkh
substitute BUF_WRITE(foo) for VOP_BWRITE(foo->b_vp, foo)
substitute BUF_STRATEGY(foo) for VOP_STRATEGY(foo->b_vp, foo)
This patch is machine generated except for the ccd.c and buf.h parts.
field in struct buf: b_iocmd. The b_iocmd is enforced to have
exactly one bit set.
B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.
Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.
Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue. It is likely to write on your disk
where it should have been reading.
This change is a step in the direction towards a stackable BIO capability.
A lot of this patch were machine generated (Thanks to style(9) compliance!)
Vinum users: Greg has not had time to test this yet, be careful.
Fix potential bug with directory reading.
Explicitly limit file size to 4GB (msdos can't handle larger files).
Slightly reorganize msdosfs_read() to reduce number of 'if's.
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.
the creation time for files to the uninitialized value:
vap->va_ctime = vap->va_ctime;
Changed to what was intended, assigning it to the modification time (thus
making all three values of access time, modification time and creation time
the same thing).
Reviewed by: grog
* lockstatus() and VOP_ISLOCKED() gets a new process argument and a new
return value: LK_EXCLOTHER, when the lock is held exclusively by another
process.
* The ASSERT_VOP_(UN)LOCKED family is extended to use what this gives them
* Extend the vnode_if.src format to allow more exact specification than
locked/unlocked.
This commit should not do any semantic changes unless you are using
DEBUG_VFS_LOCKS.
Discussed with: grog, mch, peter, phk
Reviewed by: peter
maps onto the upages. We used to use this extensively, particularly
for ps and gdb. Both of these have been "fixed". ps gets the p_stats
via eproc along with all the other stats, and gdb uses the regs, fpregs
etc files.
Once apon a time the UPAGES were mapped here, but that changed back
in January '96. This essentially kills my revisions 1.16 and 1.17.
The 2-page "hole" above the stack can be reclaimed now.
1. ntfs_read*attr*() functions now accept
uio structure to eliminate one data copying.
2. found and removed deadlock caused
by 6 concurent ls -lR.
3. started implementation of nromal
Unicode<->unix recodeing.
Obtained from: NetBSD
drops the counting in bwrite and puts it all in spec_strategy.
I did some tests and verified that the counts collected for writes
in spec_strategy is identical to the counts that we previously
collected in bwrite. We now also get read counts (async reads
come from requests for read-ahead blocks). Note that you need
to compile a new version of mount to get the read counts printed
out. The old mount binary is completely compatible, the only
reason to install a new mount is to get the read counts printed.
Submitted by: Craig A Soules <soules+@andrew.cmu.edu>
Reviewed by: Kirk McKusick <mckusick@mckusick.com>
p_trespass(struct proc *p1, struct proc *p2)
which returns zero or an errno depending on the legality of p1 trespassing
on p2.
Replace kern_sig.c:CANSIGNAL() with call to p_trespass() and one
extra signal related check.
Replace procfs.h:CHECKIO() macros with calls to p_trespass().
Only show command lines to process which can trespass on the target
process.
Note: Previous commit to these files (except coda_vnops and devfs_vnops)
that claimed to remove WILLRELE from VOP_RENAME actually removed it from
VOP_MKNOD.
Correctly lock vnodes when calling VOP_OPEN() from filesystem mount code.
Unify spec_open() for bdev and cdev cases.
Remove the disabled bdev specific read/write code.
file object. Also explain some possible directions to re-implement it --
I'm not sure it should be, given the minimal application use. (Other
than having the debugger automatically access the symbols for a process,
the main use I'd found was with some minor accounting ability, but _that_
depends on it being in the filesystem space; an ioctl access method would
be useless in that case.)
This is a code-less change; only a comment has been added.
continue doing it despite objections by me (the principal author).
Note that this doesn't fix the real problem -- the real problem is generally
bad setup by ignorant users, and education is the right way to fix it.
So while this doesn't actually solve the prolem mentioned in the complaint
(since it's still possible to do it via other methods, although they mostly
involve a bit more complicity), and there are better methods to do this,
nobody was willing or able to provide me with a real world example that
couldn't be worked around using the existing permissions and group
mechanism. And therefore, security by removing features is the method of
the day.
I only had three applications that used it, in any event. One of them would
have made debugging easier, but I still haven't finished it, and won't
now, so it doesn't really matter.
Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>. This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.
This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.
to remove 'b'lock devices. The agreement is, essentially, that
block devices will be collapsed into character devices as a first
step (though I don't particularly agree), and raw device names 'rxxx'
will become simply 'xxx' in devfs in the second step (i.e. no 'rxxx'
names will exist). The renaming will not effect the original /dev
and the expectation is that devfs will eventually (but not immediately)
become the standard way to access devices in the system.
If it is determined that a reimplementation of block device access
characteristics is beneficial, a number of alternatives will
be possible that do not involve resurrecting the 'b'lock device class.
For example, an ioctl() that might be made on an open character device
descriptor or a generic buffered overlay device.
This commit removes the blockdev disablement sysctl which does not
apply to the solution that was reached.
This means that access to block devices nodes will act the
same as char device nodes for disk-like devices.
If you encounter problems after this, where programs accessing
disks directly fail to operate, please use the following command
to revert to previous behaviour:
sysctl -w vfs.bdev_buffered=1
And verify that this was indeed the cause of your trouble.
See the mail-archives of the arch@FreeBSD.org list for background.
two new functions spec_buf{read|write}.
Add sysctl vfs.bdev_buffered which defaults to 1 == true. This
sysctl can be used to experimentally turn buffered behaviour for
bdevs off. I should not be changed while any blockdevices are
open. Remove the misplaced sysctl vfs.enable_userblk_io.
No other changes in behaviour.
-----------------------------
The core of the signalling code has been rewritten to operate
on the new sigset_t. No methodological changes have been made.
Most references to a sigset_t object are through macros (see
signalvar.h) to create a level of abstraction and to provide
a basis for further improvements.
The NSIG constant has not been changed to reflect the maximum
number of signals possible. The reason is that it breaks
programs (especially shells) which assume that all signals
have a non-null name in sys_signame. See src/bin/sh/trap.c
for an example. Instead _SIG_MAXSIG has been introduced to
hold the maximum signal possible with the new sigset_t.
struct sigprop has been moved from signalvar.h to kern_sig.c
because a) it is only used there, and b) access must be done
though function sigprop(). The latter because the table doesn't
holds properties for all signals, but only for the first NSIG
signals.
signal.h has been reorganized to make reading easier and to
add the new and/or modified structures. The "old" structures
are moved to signalvar.h to prevent namespace polution.
Especially the coda filesystem suffers from the change, because
it contained lines like (p->p_sigmask == SIGIO), which is easy
to do for integral types, but not for compound types.
NOTE: kdump (and port linux_kdump) must be recompiled.
Thanks to Garrett Wollman and Daniel Eischen for pressing the
importance of changing sigreturn as well.
