alc [Sat, 15 Jan 2005 21:12:47 +0000 (21:12 +0000)]
Consider three objects, O, BO, and BBO, where BO is O's backing object
and BBO is BO's backing object. Now, suppose that O and BO are being
collapsed. Furthermore, suppose that BO has been marked dead
(OBJ_DEAD) by vm_object_backing_scan() and that either
vm_object_backing_scan() has been forced to sleep due to encountering
a busy page or vm_object_collapse() has been forced to sleep due to
memory allocation in the swap pager. If vm_object_deallocate() is
then called on BBO and BO is BBO's only shadow object,
vm_object_deallocate() will collapse BO and BBO. In doing so, it adds
a necessary temporary reference to BO. If this collapse also sleeps
and the prior collapse resumes first, the temporary reference will
cause vm_object_collapse to panic with the message "backing_object %p
was somehow re-referenced during collapse!"
Resolve this race by changing vm_object_deallocate() such that it
doesn't collapse BO and BBO if BO is marked dead. Once O and BO are
collapsed, vm_object_collapse() will attempt to collapse O and BBO.
So, vm_object_deallocate() on BBO need do nothing.
Reported by: Peter Holm on 20050107
URL: http://www.holm.cc/stress/log/cons102.html
In collaboration with: tegge@
Candidate for RELENG_4 and RELENG_5
MFC after: 2 weeks
pjd [Sat, 15 Jan 2005 17:09:53 +0000 (17:09 +0000)]
Fix ACLs handling for the root file system.
Without this fix, when ACLs are set via tunefs(8) on the root file system,
they are removed on boot when 'mount -a' is called, because mount(8)
called for the root file system always add MNT_UPDATE flag and MNT_UPDATE
flag isn't perfect.
Now, one cannot remove ACLs stored in superblock (configured with tunefs(8))
via 'mount -a' nor 'mount -u -o noacls <file system>', but it is still
possible to mount file system which doesn't have ACLs in superblock via
'mount -o acls <file system>' or /etc/fstab's 'acls' option.
das [Sat, 15 Jan 2005 05:26:32 +0000 (05:26 +0000)]
Add a file missed in the previous commit:
Eliminate gdtoa.mk and move its contents to ${MACHINE_ARCH}/Makefile.inc.
The purpose of having a separate file involved an abandoned scheme that
would have kept contrib/gdtoa out of the include path for the rest of libc.
das [Sat, 15 Jan 2005 05:23:58 +0000 (05:23 +0000)]
Eliminate gdtoa.mk and move its contents to ${MACHINE_ARCH}/Makefile.inc.
The purpose of having a separate file involved an abandoned scheme that
would have kept contrib/gdtoa out of the include path for the rest of libc.
das [Sat, 15 Jan 2005 02:55:10 +0000 (02:55 +0000)]
Most libm routines depend on the rounding mode and/or set exception
flags, so they are not pure. Remove the __pure2 annotation from them.
I believe that the following routines and their float and long double
counterparts are the only ones here that can be __pure2:
copysign is* fabs finite fmax fmin fpclassify ilogb nan signbit
When gcc supports FENV_ACCESS, perhaps there will be a new annotation
that allows the other functions to be considered pure when FENV_ACCESS
is off.
brooks [Sat, 15 Jan 2005 01:46:41 +0000 (01:46 +0000)]
Deprecate unmaintainable uses of strncmp to implement abbreviations.
This commit replaces those with two new functions that simplify the code
and produce warnings that the syntax is deprecated. A small number of
sensible abbreviations may be explicitly added based on user feedback.
There were previously three types of strncmp use in ipfw:
- Most commonly, strncmp(av, "string", sizeof(av)) was used to allow av
to match string or any shortened form of it. I have replaced this
with a new function _substrcmp(av, "string") which returns 0 if av
is a substring of "string", but emits a warning if av is not exactly
"string".
- The next type was two instances of strncmp(av, "by", 2) which allowed
the abbreviation of bytes to "by", "byt", etc. Unfortunately, it
also supported "bykHUygh&*g&*7*ui". I added a second new function
_substrcmp2(av, "by", "bytes") which acts like the strncmp did, but
complains if the user doesn't spell out the word "bytes".
- There is also one correct use of strncmp to match "table(" which might
have another token after it without a space.
Since I changed all the lines anyway, I also fixed the treatment of
strncmp's return as a boolean in many cases. I also modified a few
strcmp cases as well to be fully consistent.
das [Fri, 14 Jan 2005 23:28:28 +0000 (23:28 +0000)]
Remove numerous references to VAX floating-point and the setting of
errno, replacing them with a discussion of IEEE exceptions where
appropriate. Cross-reference fenv(3) whenever exceptions are
mentioned.
wpaul [Fri, 14 Jan 2005 22:39:44 +0000 (22:39 +0000)]
Fix a problem reported by Pierre Beyssac. Sometinmes when ndis_get_info()
calls MiniportQueryInformation(), it will return NDIS_STATUS_PENDING.
When this happens, ndis_get_info() will sleep waiting for a completion
event. If two threads call ndis_get_info() and both end up having to
sleep, they will both end up waiting on the same wait channel, which
can cause a panic in sleepq_add() if INVARIANTS are turned on.
Fix this by having ndis_get_info() use a common mutex rather than
using the process mutex with PROC_LOCK(). Also do the same for
ndis_set_info(). Note that Pierre's original patch also made ndis_thsuspend()
use the new mutex, but ndis_thsuspend() shouldn't need this since
it will make each thread that calls it sleep on a unique wait channel.
Also, it occured to me that we probably don't want to enter
MiniportQueryInformation() or MiniportSetInformation() from more
than one thread at any given time, so now we acquire a Windows
spinlock before calling either of them. The Microsoft documentation
says that MiniportQueryInformation() and MiniportSetInformation()
are called at DISPATCH_LEVEL, and previously we would call
KeRaiseIrql() to set the IRQL to DISPATCH_LEVEL before entering
either routine, but this only guarantees mutual exclusion on
uniprocessor machines. To make it SMP safe, we need to use a real
spinlock. For now, I'm abusing the spinlock embedded in the
NDIS_MINIPORT_BLOCK structure for this purpose. (This may need to be
applied to some of the other routines in kern_ndis.c at a later date.)
Export ntoskrnl_init_lock() (KeInitializeSpinlock()) from subr_ntoskrnl.c
since we need to use in in kern_ndis.c, and since it's technically part
of the Windows kernel DDK API along with the other spinlock routines. Use
it in subr_ndis.c too rather than frobbing the spinlock directly.
das [Fri, 14 Jan 2005 22:03:27 +0000 (22:03 +0000)]
Set math_errhandling to MATH_ERREXCEPT. Now that we have fenv.h, we
basically support this, subject to gcc's lack of FENV_ACCESS support.
In any case, the previous setting of math_errhandling to 0 is not
allowed by POSIX.
phk [Fri, 14 Jan 2005 21:05:35 +0000 (21:05 +0000)]
CAM will sometimes remove a disk again even before it finished being
initialized. We already cancel the pending events but we need to not
dereference the geom pointer which never got set different from NULL.
jhb [Fri, 14 Jan 2005 20:16:41 +0000 (20:16 +0000)]
Remove redundant code to drop per-thread debug register state from
cpu_exit() as this is already performed in cpu_thread_exit() and the
debug state is per-thread rather than per-process.
jhb [Fri, 14 Jan 2005 20:13:04 +0000 (20:13 +0000)]
- Remove some OBE comments regarding cpu_exit(). cpu_exit() is no longer
the last action of kern_exit(). Instead, it is a MD callout to cleanup
per-process state during exit.
- Add notes of concern to Alpha and ia64 about the possible need to drop
fp state in cpu_thread_exit() rather than in cpu_exit() since it is
per-thread state rather than per-process.
davidxu [Fri, 14 Jan 2005 13:38:15 +0000 (13:38 +0000)]
make umtx timeout relative so userland can select different clock type,
e.g, CLOCK_REALTIME or CLOCK_MONOTONIC.
merge umtx_wait and umtx_timedwait into single function.
delphij [Fri, 14 Jan 2005 12:22:57 +0000 (12:22 +0000)]
64-bit clean + WARNS=6:
- Convert the (char *) cast+cast backs magic to
memcpy(3). Without this, the resulting code
is potentially risky with higher optimization
levels.
- Avoid same name when calling local variables,
as well as global symbols. This reduces
confusion for both human and compiler.
- Add necessary casts, consts
- Use new style function defination.
- Minor style.Makefile(5) tweak
- Bump WARNS?= from 0 to 6
** for the aout code: changes are intentionally limited
to ease maintaince.
glebius [Fri, 14 Jan 2005 09:00:46 +0000 (09:00 +0000)]
o Clean up interface between ip_fw_chk() and its callers:
- ip_fw_chk() returns action as function return value. Field retval is
removed from args structure. Action is not flag any more. It is one
of integer constants.
- Any action-specific cookies are returned either in new "cookie" field
in args structure (dummynet, future netgraph glue), or in mbuf tag
attached to packet (divert, tee, some future action).
o Convert parsing of return value from ip_fw_chk() in ipfw_check_{in,out}()
to a switch structure, so that the functions are more readable, and a future
actions can be added with less modifications.
das [Fri, 14 Jan 2005 07:09:23 +0000 (07:09 +0000)]
Mark all inline asms that read the floating-point control or status
registers as volatile. Instructions that *wrote* to FP state were
already marked volatile, but apparently gcc has license to move
non-volatile asms past volatile asms. This broke amd64's feupdateenv
at -O2 due to a WAR conflict between fnstsw and fldenv there.
das [Thu, 13 Jan 2005 18:58:25 +0000 (18:58 +0000)]
Import the subset of J.T. Conklin's single-precision x86-optimized
math routines that appear to be (a) correct and (b) faster than their
MI counterparts on my Pentium 4.