and the new setmode and setowner fileops in FreeBSD 9.0:
- Add new MAC Framework entry point mac_posixshm_check_create() to allow
MAC policies to authorise shared memory use. Provide a stub policy and
test policy templates.
- Add missing Biba and MLS implementations of mac_posixshm_check_setmode()
and mac_posixshm_check_setowner().
- Add 'accmode' argument to mac_posixshm_check_open() -- unlike the
mac_posixsem_check_open() entry point it was modeled on, the access mode
is required as shared memory access can be read-only as well as writable;
this isn't true of POSIX semaphores.
- Implement full range of POSIX shared memory entry points for Biba and MLS.
Sponsored by: Google Inc.
Obtained from: TrustedBSD Project
Approved by: re (kib)
accessible:
(1) Always compile in support for breaking into the debugger if options
KDB is present in the kernel.
(2) Disable both by default, but allow them to be enabled via tunables
and sysctls debug.kdb.break_to_debugger and
debug.kdb.alt_break_to_debugger.
(3) options BREAK_TO_DEBUGGER and options ALT_BREAK_TO_DEBUGGER continue
to behave as before -- only now instead of compiling in
break-to-debugger support, they change the default values of the
above sysctls to enable those features by default. Current kernel
configurations should, therefore, continue to behave as expected.
(4) Migrate alternative break-to-debugger state machine logic out of
individual device drivers into centralised KDB code. This has a
number of upsides, but also one downside: it's now tricky to release
sio spin locks when entering the debugger, so we don't. However,
similar logic does not exist in other device drivers, including uart.
(5) dcons requires some special handling; unlike other console types, it
allows overriding KDB's own debugger selection, so we need a new
interface to KDB to allow that to work.
GENERIC kernels in -CURRENT will now support break-to-debugger as long as
appropriate boot/run-time options are set, which should improve the
debuggability of BETA kernels significantly.
MFC after: 3 weeks
Reviewed by: kib, nwhitehorn
Approved by: re (bz)
but not removed; decrement it instead when the child jail actually
goes away. This avoids letting the counter go below zero in the case
where dying (pr_uref==0) jails are "resurrected", and an associated
KASSERT panic.
Submitted by: Steven Hartland
Approved by: re (bz)
MFC after: 1 week
If a selinfo object is recorded (via selrecord()) and then it is
quickly destroyed, with the waiters missing the opportunity to awake,
at the next iteration they will find the selinfo object destroyed,
causing a PF#.
That happens because the selinfo interface has no way to drain the
waiters before to destroy the registered selinfo object. Also this
race is quite rare to get in practice, because it would require a
selrecord(), a poll request by another thread and a quick destruction
of the selrecord()'ed selinfo object.
Fix this by adding the seldrain() routine which should be called
before to destroy the selinfo objects (in order to avoid such case),
and fix the present cases where it might have already been called.
Sometimes, the context is safe enough to prevent this type of race,
like it happens in device drivers which installs selinfo objects on
poll callbacks. There, the destruction of the selinfo object happens
at driver detach time, when all the filedescriptors should be already
closed, thus there cannot be a race.
For this case, mfi(4) device driver can be set as an example, as it
implements a full correct logic for preventing this from happening.
Sponsored by: Sandvine Incorporated
Reported by: rstone
Tested by: pluknet
Reviewed by: jhb, kib
Approved by: re (bz)
MFC after: 3 weeks
and the maximum TCP send and receive buffer limits from 256kB
to 2MB.
For sb_max_adj we need to add the cast as already used in the sysctl
handler to not overflow the type doing the maths.
Note that this is just the defaults. They will allow more memory
to be consumed per socket/connection if needed but not change the
default "idle" memory consumption. All values are still tunable
by sysctls.
Suggested by: gnn
Discussed on: arch (Mar and Aug 2011)
MFC after: 3 weeks
Approved by: re (kib)
Remove mapped pages for all dataset vnodes in zfs_rezget() using
new vn_pages_remove() to fix mmapped files changed by
zfs rollback or zfs receive -F.
PR: kern/160035, kern/156933
Reviewed by: kib, pjd
Approved by: re (kib)
MFC after: 1 week
callout cpu lock (and after having dropped it).
If the newly scheduled thread wants to acquire the old queue it will
just spin forever.
Fix this by disabling preemption and interrupts entirely (because fast
interrupt handlers may incur in the same problem too) while switching
locks.
Reported by: hrs, Mike Tancsa <mike AT sentex DOT net>,
Chip Camden <sterling AT camdensoftware DOT com>
Tested by: hrs, Mike Tancsa <mike AT sentex DOT net>,
Chip Camden <sterling AT camdensoftware DOT com>,
Nicholas Esborn <nick AT desert DOT net>
Approved by: re (kib)
MFC after: 10 days
effectively negative. Often seen as upstream fastcgi connection timeouts
in nginx when using sendfile over unix domain sockets for communication.
Sendfile(2) may send more bytes then currently allowed by the
hiwatermark of the socket, e.g. because the so_snd sockbuf lock is
dropped after sbspace() call in the kern_sendfile() loop. In this case,
recalculated hiwatermark will overflow. Since lowatermark is renewed
as half of the hiwatermark by sendfile code, and both are unsigned,
the send buffer never reaches the free space requested by lowatermark,
causing indefinite wait in sendfile.
Reviewed by: rwatson
Approved by: re (bz)
MFC after: 2 weeks
buffer is greater than 1. This triggered panics in at least one spot in
the kernel (the MAC Framework) which passes non-negative, rather than >1
buffer sizes based on the size of a user buffer passed into a system
call. While 0-size buffers aren't particularly useful, they also aren't
strictly incorrect, so loosen the assertion.
Discussed with: phk (fears I might be EDOOFUS but willing to go along)
Spotted by: pho + stress2
Approved by: re (kib)
A "process descriptor" file descriptor is used to manage processes
without using the PID namespace. This is required for Capsicum's
Capability Mode, where the PID namespace is unavailable.
New system calls pdfork(2) and pdkill(2) offer the functional equivalents
of fork(2) and kill(2). pdgetpid(2) allows querying the PID of the remote
process for debugging purposes. The currently-unimplemented pdwait(2) will,
in the future, allow querying rusage/exit status. In the interim, poll(2)
may be used to check (and wait for) process termination.
When a process is referenced by a process descriptor, it does not issue
SIGCHLD to the parent, making it suitable for use in libraries---a common
scenario when using library compartmentalisation from within large
applications (such as web browsers). Some observers may note a similarity
to Mach task ports; process descriptors provide a subset of this behaviour,
but in a UNIX style.
This feature is enabled by "options PROCDESC", but as with several other
Capsicum kernel features, is not enabled by default in GENERIC 9.0.
Reviewed by: jhb, kib
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
query the needed size for a sysctl result by passing in a NULL old
pointer and a valid oldsize. The kern.proc.args sysctl handler broke
this assumption by not calling SYSCTL_OUT() if the old pointer was
NULL.
Approved by: re (kib)
MFC after: 3 days
to implement fchown(2) and fchmod(2) support for several file types
that previously lacked it. Add MAC entries for chown/chmod done on
posix shared memory and (old) in-kernel posix semaphores.
Based on the submission by: glebius
Reviewed by: rwatson
Approved by: re (bz)
When calling poll(2) on a capability, unwrap first and then poll the
underlying object.
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
a bug was introduced in kern_openat() such that the error from the vnode
open operation was overwritten before it was passed as an argument to
dupfdopen(). This broke operations on /dev/{stdin,stdout,stderr}. Fix
by preserving the original error number across finstall() so that it is
still available.
Approved by: re (kib)
Reported by: cognet
A no-op for non-Capsicum kernels; for Capsicum kernels, completes the
enabling of fooat(2) system calls using capabilities. With this change,
and subject to bug fixes, Capsicum capability support is now complete for
9.0.
Approved by: re (kib)
Submitted by: jonathan
Sponsored by: Google Inc
namei() and lookup() can now perform "strictly relative" lookups.
Such lookups, performed when in capability mode or when looking up
relative to a directory capability, enforce two policies:
- absolute paths are disallowed (including symlinks to absolute paths)
- paths containing '..' components are disallowed
These constraints make it safe to enable openat() and friends.
These system calls are instrumental in supporting Capsicum
components such as the capability-mode-aware runtime linker.
Finally, adjust comments in capabilities.conf to reflect the actual state
of the world (e.g. shm_open(2) already has the appropriate constraints,
getdents(2) already requires CAP_SEEK).
Approved by: re (bz), mentor (rwatson)
Sponsored by: Google Inc.
access to file system subtrees to sandboxed processes.
- Use of absolute paths and '..' are limited in capability mode.
- Use of absolute paths and '..' are limited when looking up relative
to a capability.
- When a name lookup is performed, identify what operation is to be
performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP.
With these constraints, openat() and friends are now safe in capability
mode, and can then be used by code such as the capability-mode runtime
linker.
Approved by: re (bz), mentor (rwatson)
Sponsored by: Google Inc
Since kern_openat() now uses falloc_noinstall() and finstall() separately,
there are cases where we could get to cleanup code without ever creating
a file descriptor. In those cases, we should not call fdclose() on FD -1.
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
kernel for FreeBSD 9.0:
Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.
Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.
In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.
Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.
Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc
doesn't operate on locked vnode. This could cause a panic.
Fix by unlocking vnode, re-locking afterwards and verifying that it wasn't
renamed or deleted. To improve readability and reduce code size, move code
to a new static function vfs_verify_global_path().
In addition, fix missing giant unlock in unmount().
Reported by: David Wolfskill <david@catwhisker.org>
Reviewed by: kib
Approved by: re (bz)
MFC after: 2 weeks
using vn_fullpath_global(). This fixes f_mntonname if mounting
inside chroot, jail or with relative path as argument.
For unmount in jail, use vn_fullpath_global() to discover
global path from supplied path argument. This fixes unmount in jail.
Reviewed by: pjd, kib
Approved by: re (kib)
MFC after: 2 weeks
This is a followup to r222032 and a reimplementation of it.
While that revision fixed the race for the smp_rv_waiters[2] exit
sentinel, it still left a possibility for a target CPU to access
stale or wrong smp_rv_func_arg in smp_rv_teardown_func.
To fix this race the slave CPUs signal when they are really fully
done with the rendezvous and the master CPU waits until all slaves
are done.
Diagnosed by: kib
Reviewed by: jhb, mlaier, neel
Approved by: re (kib)
MFC after: 2 weeks
This is done per request/suggestion from John Baldwin
who introduced the option. Trying to resume normal
system operation after a panic is very unpredictable
and dangerous. It will become even more dangerous
when we allow a thread in panic(9) to penetrate all
lock contexts.
I understand that the only purpose of this option was
for testing scenarios potentially resulting in panic.
Suggested by: jhb
Reviewed by: attilio, jhb
X-MFC-After: never
Approved by: re (kib)
so that it is visible to userland programs. This change enables
the `mount' command with no arguments to be able to show if a
filesystem is mounted using journaled soft updates as opposed
to just normal soft updates.
Approved by: re (bz)
32 bits to 64 bits and eliminates the unused mnt_xflag field. The
existing mnt_flag field is completely out of bits, so this update
gives us room to expand. Note that the f_flags field in the statfs
structure is already 64 bits, so the expanded mnt_flag field can
be exported without having to make any changes in the statfs structure.
Approved by: re (bz)
Now that the code is in place to audit capability method rights, start
using it to audit the 'rights' argument to cap_new(2).
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
When reporting on a capability, flag the fact that it is a capability,
but also unwrap to report all of the usual information about the
underlying file.
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
pollution. That is a step further in the direction of building correct
policies for userland and modules on how to deal with the number of
maxcpus at runtime.
Reported by: jhb
Reviewed and tested by: pluknet
Approved by: re (kib)
pc_name is only included when KTR option is and it does introduce a
subdle KBI breakage that totally breaks vmstat when world and kernel are
not in sync.
Besides, it is not used somewhere.
In collabouration with: pluknet
Reviewed by: jhb
Approved by: re (kib)
ki_rusage member when KERN_PROC_INC_THREAD is passed to one of the
process sysctls.
- Correctly account for the current thread's cputime in the thread when
doing the runtime fixup in calcru().
- Use TIDs as the key to lookup the previous thread to compute IO stat
deltas in IO mode in top when thread display is enabled.
Reviewed by: kib
Approved by: re (kib)
sintrcnt/sintrnames which are symbols containing the size of the 2
tables.
- For amd64/i386 remove the storage of intr* stuff from assembly files.
This area can be widely improved by applying the same to other
architectures and likely finding an unified approach among them and
move the whole code to be MI. More work in this area is expected to
happen fairly soon.
No MFC is previewed for this patch.
Tested by: pluknet
Reviewed by: jhb
Approved by: re (kib)
may be jointly referenced via the mask CTLFLAG_CAPRW. Sysctls with these
flags are available in Capsicum's capability mode; other sysctl nodes are
not.
Flag several useful sysctls as available in capability mode, such as memory
layout sysctls required by the run-time linker and malloc(3). Also expose
access to randomness and available kernel features.
A few sysctls are enabled to support name->MIB conversion; these may leak
information to capability mode by virtue of providing resolution on names
not flagged for access in capability mode. This is, generally, not a huge
problem, but might be something to resolve in the future. Flag these cases
with XXX comments.
Submitted by: jonathan
Sponsored by: Google, Inc.
sampling mode PMC is allocated, hwpmc calls linker_hwpmc_list_objects()
while already holding an exclusive lock on pmc-sx lock. list_objects()
tries to acquire an exclusive lock on the kld_sx lock. When a KLD module
is loaded or unloaded successfully, kern_kld(un)load calls into the pmc
hook while already holding an exclusive lock on the kld_sx lock. Calling
the pmc hook requires acquiring a shared lock on the pmc-sx lock.
Fix this by only acquiring a shared lock on the kld_sx lock in
linker_hwpmc_list_objects(), and also downgrading to a shared lock on the
kld_sx lock in kern_kld(un)load before calling into the pmc hook. In
kern_kldload this required moving some modifications of the linker_file_t
to happen before calling into the pmc hook.
This fixes the deadlock by ensuring that the hwpmc -> list_objects() case
is always able to proceed. Without this patch, I was able to deadlock a
multicore system within minutes by constantly loading and unloading an KLD
module while I simultaneously started a sampling mode PMC in a loop.
MFC after: 1 month
Implement two previously-reserved Capsicum system calls:
- cap_new() creates a capability to wrap an existing file descriptor
- cap_getrights() queries the rights mask of a capability.
Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
Code to actually implement Capsicum capabilities, including fileops and
kern_capwrap(), which creates a capability to wrap an existing file
descriptor.
We also modify kern_close() and closef() to handle capabilities.
Finally, remove cap_filelist from struct capability, since we don't
actually need it.
Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
