potential lock order reversal. Also, don't unlock the vnode if this
fails, lockmgr has already unlocked it for us.
- Restructure vget() now that vn_lock() does all of VI_DOOMED checking
for us and also handles the case where there is no real lock type.
- If VI_OWEINACT is set, we need to upgrade the lock request to EXCLUSIVE
so that we can call inactive. It's not legal to vget a vnode that hasn't
had INACTIVE called yet.
Sponsored by: Isilon Systems, Inc.
as I'd like to get rid of the vxthread.
- Handle lock requests which don't actually want a lock as this is a
much more convenient place to handle this condition than in vget().
These requests simply want to know that VI_DOOMED isn't set.
- Correct a test at the end of vn_lock, if error !=0 should be
if error == 0, this has been broken since I comitted the VI_DOOMED
changes, but no one ran into it because vget() duplicated this
functionality.
Sponsored by: Isilon Systems, Inc.
layer, but with a twist.
The twist has to do with the fact that Microsoft supports structured
exception handling in kernel mode. On the i386 arch, exception handling
is implemented by hanging an exception registration list off the
Thread Environment Block (TEB), and the TEB is accessed via the %fs
register. The problem is, we use %fs as a pointer to the pcpu stucture,
which means any driver that tries to write through %fs:0 will overwrite
the curthread pointer and make a serious mess of things.
To get around this, Project Evil now creates a special entry in
the GDT on each processor. When we call into Windows code, a context
switch routine will fix up %fs so it points to our new descriptor,
which in turn points to a fake TEB. When the Windows code returns,
or calls out to an external routine, we swap %fs back again. Currently,
Project Evil makes use of GDT slot 7, which is all 0s by default.
I fully expect someone to jump up and say I can't do that, but I
couldn't find any code that makes use of this entry anywhere. Sadly,
this was the only method I could come up with that worked on both
UP and SMP. (Modifying the LDT works on UP, but becomes incredibly
complicated on SMP.) If necessary, the context switching stuff can
be yanked out while preserving the convention calling wrappers.
(Fortunately, it looks like Microsoft uses some special epilog/prolog
code on amd64 to implement exception handling, so the same nastiness
won't be necessary on that arch.)
The advantages are:
- Any driver that uses %fs as though it were a TEB pointer won't
clobber pcpu.
- All the __stdcall/__fastcall/__regparm stuff that's specific to
gcc goes away.
Also, while I'm here, switch NdisGetSystemUpTime() back to using
nanouptime() again. It turns out nanouptime() is way more accurate
than just using ticks(). On slower machines, the Atheros drivers
I tested seem to take a long time to associate due to the loss
in accuracy.
systems that boot with this value at the lowest setting. Change the
default boot config back to "leave frequency as BIOS set it". Also, fix
buglet where acpi_throttle wouldn't be used if p4tcc was present but
disabled by the user.
MFC after: 1 week
a return instruction. (The latter is discouraged by the Opteron
optimization manual because it disables branch prediction for the return
instruction.)
Reviewed by: bde
Affects to people WITH an AD1888 codec, the system will output to the port
labeled "speaker" instead of microphone. System will work the same in
multiple operating systems.
If people are currently using their systems with this codec they will need
to swap their output ports.
I have _not_ checked audio input or line input (basically, I have checked
nothing other than line-out).
I believe this is an appropriate change, it makes us consistent with
documentation, and other operating systems. Furthermore, this feature
(playing) is the vast majority of sound activities, so if this makes is
right for playback and wrong for recording... playback is more important,
and we can fix recoding in the future without worries of screwing people
again in the future (since we'll be "right" on the playback).
Submitted by: David Cross
setting ts_recent to an arbitrary value, stopping further
communication between the two hosts.
- If the Echoed Timestamp is greater than the current time,
fall back to the non RFC 1323 RTT calculation.
Submitted by: Raja Mukerji (raja at moselle dot com)
Reviewed by: Noritoshi Demizu, Mohan Srinivasan
a reassembly queue state structure, don't update (receiver) sack
report.
- Similarly, if tcp_drain() is called, freeing up all items on the
reassembly queue, clean the sack report.
Found, Submitted by: Noritoshi Demizu <demizu at dd dot iij4u dot or dot jp>
Reviewed by: Mohan Srinivasan (mohans at yahoo-inc dot com),
Raja Mukerji (raja at moselle dot com).
(Fix for kern/78226).
Submitted by : Noritoshi Demizu <demizu at dd dot iij4u dot or dot jp>
Reviewed by : Mohan Srinivasan (mohans at yahoo-inc dot com),
Raja Mukerji (raja at moselle dot com).
The main reason for doing this is that the ELF dump handler expects
the thread list to be fixed while the dump header is generated, so an
upcall that occurs at the wrong time can lead to buffer overruns and
other Bad Things.
Another solution would be to grab sched_lock in the ELF dump handler,
but we might as well single-thread, since the process is about to die.
Furthermore, I think this should ensure that the register sets in the
core file are sequentially consistent.
when vrele() acquires the directory lock in the wrong order. Fix this
via the following changes:
- Keep the directory locked after VOP_LOOKUP() until we've determined
what we're going to do with the child. This allows us to remove the
complicated post LOOKUP code which determins whether we should lock or
unlock the parent. This means we may have to vput() in the appropriate
cases later, rather than doing an unsafe vrele.
- in NDFREE() keep two flags to indicate whether we need to unlock vp or
dvp. This allows us to vput rather than vrele in the appropriate
cases without rechecking the flags. Move the code to handle dvp after
we handle vp.
- Remove some dead code from namei() that was the result of changes to
VFS_LOCK_GIANT().
Sponsored by: Isilon Systems, Inc.
try to reasseble the packet from the fragments queue with the only
fragment, finish with the first fragment as soon as we create a queue.
Spotted by: Vijay Singh
o Drop the fragment if maxfragsperpacket == 0, no chances we
will be able to reassemble the packet in future.
Reviewed by: silby
ip.portrange.last and there is the only port for that because:
a) it is not wise; b) it leads to a panic in the random ip port
allocation code. In general we need to disable ip port allocation
randomization if the last - first delta is ridiculous small.
PR: kern/79342
Spotted by: Anjali Kulkarni
Glanced at by: silby
MFC after: 2 weeks
