alloc and free routine pointers in the lookaside list with pointers
to ExAllocatePoolWithTag() and ExFreePool() (in the case where the
driver does not provide its own alloc and free routines). For amd64,
this is wrong: we have to use pointers to the wrapped versions of these
functions, not the originals.
nll_obsoletelock field in the lookaside list structure is only defined
for the i386 arch. For amd64, the field is gone, and different list
update routines are used which do their locking internally. Apparently
the Inprocomm amd64 driver uses lookaside lists. I'm not positive this
will make it work yet since I don't have an Inprocomm NIC to test, but
this needs to be fixed anyway.
work on SMP" saga. After several weeks and much gnashing of teeth,
I have finally tracked down all the problems, despite their best
efforts to confound and annoy me.
Problem nunmber one: the Atheros windows driver is _NOT_ a de-serialized
miniport! It used to be that NDIS drivers relied on the NDIS library
itself for all their locking and serialization needs. Transmit packet
queues were all handled internally by NDIS, and all calls to
MiniportXXX() routines were guaranteed to be appropriately serialized.
This proved to be a performance problem however, and Microsoft
introduced de-serialized miniports with the NDIS 5.x spec. Microsoft
still supports serialized miniports, but recommends that all new drivers
written for Windows XP and later be deserialized. Apparently Atheros
wasn't listening when they said this.
This means (among other things) that we have to serialize calls to
MiniportSendPackets(). We also have to serialize calls to MiniportTimer()
that are triggered via the NdisMInitializeTimer() routine. It finally
dawned on me why NdisMInitializeTimer() takes a special
NDIS_MINIPORT_TIMER structure and a pointer to the miniport block:
the timer callback must be serialized, and it's only by saving the
miniport block handle that we can get access to the serialization
lock during the timer callback.
Problem number two: haunted hardware. The thing that was _really_
driving me absolutely bonkers for the longest time is that, for some
reason I couldn't understand, my test machine would occasionally freeze
or more frustratingly, reset completely. That's reset and in *pow!*
back to the BIOS startup. No panic, no crashdump, just a reset. This
appeared to happen most often when MiniportReset() was called. (As
to why MiniportReset() was being called, see problem three below.)
I thought maybe I had created some sort of horrible deadlock
condition in the process of adding the serialization, but after three
weeks, at least 6 different locking implementations and heroic efforts
to debug the spinlock code, the machine still kept resetting. Finally,
I started single stepping through the MiniportReset() routine in
the driver using the kernel debugger, and this ultimately led me to
the source of the problem.
One of the last things the Atheros MiniportReset() routine does is
call NdisReadPciSlotInformation() several times to inspect a portion
of the device's PCI config space. It reads the same chunk of config
space repeatedly, in rapid succession. Presumeably, it's polling
the hardware for some sort of event. The reset occurs partway through
this process. I discovered that when I single-stepped through this
portion of the routine, the reset didn't occur. So I inserted a 1
microsecond delay into the read loop in NdisReadPciSlotInformation().
Suddenly, the reset was gone!!
I'm still very puzzled by the whole thing. What I suspect is happening
is that reading the PCI config space so quickly is causing a severe
PCI bus error. My test system is a Sun w2100z dual Opteron system,
and the NIC is a miniPCI card mounted in a miniPCI-to-PCI carrier card,
plugged into a 100Mhz PCI slot. It's possible that this combination of
hardware causes a bus protocol violation in this scenario which leads
to a fatal machine check. This is pure speculation though. Really all I
know for sure is that inserting the delay makes the problem go away.
(To quote Homer Simpson: "I don't know how it works, but fire makes
it good!")
Problem number three: NdisAllocatePacket() needs to make sure to
initialize the npp_validcounts field in the 'private' section of
the NDIS_PACKET structure. The reason if_ndis was calling the
MiniportReset() routine in the first place is that packet transmits
were sometimes hanging. When sending a packet, an NDIS driver will
call NdisQueryPacket() to learn how many physical buffers the packet
resides in. NdisQueryPacket() is actually a macro, which traverses
the NDIS_BUFFER list attached to the NDIS_PACKET and stashes some
of the results in the 'private' section of the NDIS_PACKET. It also
sets the npp_validcounts field to TRUE To indicate that the results are
now valid. The problem is, now that if_ndis creates a pool of transmit
packets via NdisAllocatePacketPool(), it's important that each time
a new packet is allocated via NdisAllocatePacket() that validcounts
be initialized to FALSE. If it isn't, and a previously transmitted
NDIS_PACKET is pulled out of the pool, it may contain stale data
from a previous transmission which won't get updated by NdisQueryPacket().
This would cause the driver to miscompute the number of fragments
for a given packet, and botch the transmission.
Fixing these three problems seems to make the Atheros driver happy
on SMP, which hopefully means other serialized miniports will be
happy too.
And there was much rejoicing.
Other stuff fixed along the way:
- Modified ndis_thsuspend() to take a mutex as an argument. This
allows KeWaitForSingleObject() and KeWaitForMultipleObjects() to
avoid any possible race conditions with other routines that
use the dispatcher lock.
- Fixed KeCancelTimer() so that it returns the correct value for
'pending' according to the Microsoft documentation
- Modfied NdisGetSystemUpTime() to use ticks and hz rather than
calling nanouptime(). Also added comment that this routine wraps
after 49.7 days.
- Added macros for KeAcquireSpinLock()/KeReleaseSpinLock() to hide
all the MSCALL() goop.
- For x86, KeAcquireSpinLockRaiseToDpc() needs to be a separate
function. This is because it's supposed to be _stdcall on the x86
arch, whereas KeAcquireSpinLock() is supposed to be _fastcall.
On amd64, all routines use the same calling convention so we can
just map KeAcquireSpinLockRaiseToDpc() directly to KfAcquireSpinLock()
and it will work. (The _fastcall attribute is a no-op on amd64.)
- Implement and use IoInitializeDpcRequest() and IoRequestDpc() (they're
just macros) and use them for interrupt handling. This allows us to
move the ndis_intrtask() routine from if_ndis.c to kern_ndis.c.
- Fix the MmInitializeMdl() macro so that is uses sizeof(vm_offset_t)
when computing mdl_size instead of uint32_t, so that it matches the
MmSizeOfMdl() routine.
- Change a could of M_WAITOKs to M_NOWAITs in the unicode routines in
subr_ndis.c.
- Use the dispatcher lock a little more consistently in subr_ntoskrnl.c.
- Get rid of the "wait for link event" hack in ndis_init(). Now that
I fixed NdisReadPciSlotInformation(), it seems I don't need it anymore.
This should fix the witness panic a couple of people have reported.
- Use MSCALL1() when calling the MiniportHangCheck() function in
ndis_ticktask(). I accidentally missed this one when adding the
wrapping for amd64.
at some point result in a status event being triggered (it should
be a link down event: the Microsoft driver design guide says you
should generate one when the NIC is initialized). Some drivers
generate the event during MiniportInitialize(), such that by the
time MiniportInitialize() completes, the NIC is ready to go. But
some drivers, in particular the ones for Atheros wireless NICs,
don't generate the event until after a device interrupt occurs
at some point after MiniportInitialize() has completed.
The gotcha is that you have to wait until the link status event
occurs one way or the other before you try to fiddle with any
settings (ssid, channel, etc...). For the drivers that set the
event sycnhronously this isn't a problem, but for the others
we have to pause after calling ndis_init_nic() and wait for the event
to arrive before continuing. Failing to wait can cause big trouble:
on my SMP system, calling ndis_setstate_80211() after ndis_init_nic()
completes, but _before_ the link event arrives, will lock up or
reset the system.
What we do now is check to see if a link event arrived while
ndis_init_nic() was running, and if it didn't we msleep() until
it does.
Along the way, I discovered a few other problems:
- Defered procedure calls run at PASSIVE_LEVEL, not DISPATCH_LEVEL.
ntoskrnl_run_dpc() has been fixed accordingly. (I read the documentation
wrong.)
- Similarly, the NDIS interrupt handler, which is essentially a
DPC, also doesn't need to run at DISPATCH_LEVEL. ndis_intrtask()
has been fixed accordingly.
- MiniportQueryInformation() and MiniportSetInformation() run at
DISPATCH_LEVEL, and each request must complete before another
can be submitted. ndis_get_info() and ndis_set_info() have been
fixed accordingly.
- Turned the sleep lock that guards the NDIS thread job list into
a spin lock. We never do anything with this lock held except manage
the job list (no other locks are held), so it's safe to do this,
and it's possible that ndis_sched() and ndis_unsched() can be
called from DISPATCH_LEVEL, so using a sleep lock here is
semantically incorrect. Also updated subr_witness.c to add the
lock to the order list.
that describe a buffer of variable size). The problem is, allocating
MDLs off the heap is slow, and it can happen that drivers will allocate
lots and lots of lots of MDLs as they run.
As a compromise, we now do the following: we pre-allocate a zone for
MDLs big enough to describe any buffer with 16 or less pages. If
IoAllocateMdl() needs a MDL for a buffer with 16 or less pages, we'll
allocate it from the zone. Otherwise, we allocate it from the heap.
MDLs allocate from the zone have a flag set in their mdl_flags field.
When the MDL is released, IoMdlFree() will uma_zfree() the MDL if
it has the MDL_ZONE_ALLOCED flag set, otherwise it will release it
to the heap.
The assumption is that 16 pages is a "big number" and we will rarely
need MDLs larger than that.
- Moved the ndis_buffer zone to subr_ntoskrnl.c from kern_ndis.c
and named it mdl_zone.
- Modified IoAllocateMdl() and IoFreeMdl() to use uma_zalloc() and
uma_zfree() if necessary.
- Made ndis_mtop() use IoAllocateMdl() instead of calling uma_zalloc()
directly.
Inspired by: discussion with Giridhar Pemmasani
- In kern_ndis.c:ndis_unload_driver(), test that ndis_block->nmb_rlist
is not NULL before trying to free() it.
- In subr_pe.c:pe_get_import_descriptor(), do a case-insensitive
match on the import module name. Most drivers I have encountered
link against "ntoskrnl.exe" but the ASIX USB ethernet driver I'm
testing with wants "NTOSKRNL.EXE."
- In subr_ntoskrnl.c:IoAllocateIrp(), return a pointer to the IRP
instead of NULL. (Stub code leftover.)
- Also in subr_ntoskrnl.c, add ExAllocatePoolWithTag() and ExFreePool()
to the function table list so they'll get exported to drivers properly.
and a machine-independent though inefficient InterlockedExchange().
In Windows, InterlockedExchange() appears to be implemented in header
files via inline assembly. I would prefer using an atomic.h macro for
this, but there doesn't seem to be one that just does a plain old
atomic exchange (as opposed to compare and exchange). Also implement
IoSetCancelRoutine(), which is just a macro that uses InterlockedExchange().
Fill in IoBuildSynchronousFsdRequest(), IoBuildAsynchronousFsdRequest()
and IoBuildDeviceIoControlRequest() so that they do something useful,
and add a bunch of #defines to ntoskrnl_var.h to help make these work.
These may require some tweaks later.
for now) exactly the same as KfAcquireSpinLock() and KfReleaseSpinLock().
I implemented the former as small routines in subr_ntoskrnl.c that just
turned around and invoked the latter. But I don't really need the wrapper
routines: I can just create an entries in the ntoskrnl func table that
map KeAcquireSpinLockRaiseToDpc() and KeReleaseSpinLock() to
KfAcquireSpinLock() and KfReleaseSpinLock() directly. This means
the stubs can go away.
Ville-Pertti Keinonen (will at exomi dot comohmygodnospampleasekthx)
deserves a big thanks for submitting initial patches to make it
work. I have mangled his contributions appropriately.
The main gotcha with Windows/x86-64 is that Microsoft uses a different
calling convention than everyone else. The standard ABI requires using
6 registers for argument passing, with other arguments on the stack.
Microsoft uses only 4 registers, and requires the caller to leave room
on the stack for the register arguments incase the callee needs to
spill them. Unlike x86, where Microsoft uses a mix of _cdecl, _stdcall
and _fastcall, all routines on Windows/x86-64 uses the same convention.
This unfortunately means that all the functions we export to the
driver require an intermediate translation wrapper. Similarly, we have
to wrap all calls back into the driver binary itself.
The original patches provided macros to wrap every single routine at
compile time, providing a secondary jump table with a customized
wrapper for each exported routine. I decided to use a different approach:
the call wrapper for each function is created from a template at
runtime, and the routine to jump to is patched into the wrapper as
it is created. The subr_pe module has been modified to patch in the
wrapped function instead of the original. (On x86, the wrapping
routine is a no-op.)
There are some minor API differences that had to be accounted for:
- KeAcquireSpinLock() is a real function on amd64, not a macro wrapper
around KfAcquireSpinLock()
- NdisFreeBuffer() is actually IoFreeMdl(). I had to change the whole
NDIS_BUFFER API a bit to accomodate this.
Bugs fixed along the way:
- IoAllocateMdl() always returned NULL
- kern_windrv.c:windrv_unload() wasn't releasing private driver object
extensions correctly (found thanks to memguard)
This has only been tested with the driver for the Broadcom 802.11g
chipset, which was the only Windows/x86-64 driver I could find.
Windows DRIVER_OBJECT and DEVICE_OBJECT mechanism so that we can
simulate driver stacking.
In Windows, each loaded driver image is attached to a DRIVER_OBJECT
structure. Windows uses the registry to match up a given vendor/device
ID combination with a corresponding DRIVER_OBJECT. When a driver image
is first loaded, its DriverEntry() routine is invoked, which sets up
the AddDevice() function pointer in the DRIVER_OBJECT and creates
a dispatch table (based on IRP major codes). When a Windows bus driver
detects a new device, it creates a Physical Device Object (PDO) for
it. This is a DEVICE_OBJECT structure, with semantics analagous to
that of a device_t in FreeBSD. The Windows PNP manager will invoke
the driver's AddDevice() function and pass it pointers to the DRIVER_OBJECT
and the PDO.
The AddDevice() function then creates a new DRIVER_OBJECT structure of
its own. This is known as the Functional Device Object (FDO) and
corresponds roughly to a private softc instance. The driver uses
IoAttachDeviceToDeviceStack() to add this device object to the
driver stack for this PDO. Subsequent drivers (called filter drivers
in Windows-speak) can be loaded which add themselves to the stack.
When someone issues an IRP to a device, it travel along the stack
passing through several possible filter drivers until it reaches
the functional driver (which actually knows how to talk to the hardware)
at which point it will be completed. This is how Windows achieves
driver layering.
Project Evil now simulates most of this. if_ndis now has a modevent
handler which will use MOD_LOAD and MOD_UNLOAD events to drive the
creation and destruction of DRIVER_OBJECTs. (The load event also
does the relocation/dynalinking of the image.) We don't have a registry,
so the DRIVER_OBJECTS are stored in a linked list for now. Eventually,
the list entry will contain the vendor/device ID list extracted from
the .INF file. When ndis_probe() is called and detectes a supported
device, it will create a PDO for the device instance and attach it
to the DRIVER_OBJECT just as in Windows. ndis_attach() will then call
our NdisAddDevice() handler to create the FDO. The NDIS miniport block
is now a device extension hung off the FDO, just as it is in Windows.
The miniport characteristics table is now an extension hung off the
DRIVER_OBJECT as well (the characteristics are the same for all devices
handled by a given driver, so they don't need to be per-instance.)
We also do an IoAttachDeviceToDeviceStack() to put the FDO on the
stack for the PDO. There are a couple of fake bus drivers created
for the PCI and pccard buses. Eventually, there will be one for USB,
which will actually accept USB IRP.s
Things should still work just as before, only now we do things in
the proper order and maintain the correct framework to support passing
IRPs between drivers.
Various changes:
- corrected the comments about IRQL handling in subr_hal.c to more
accurately reflect reality
- update ndiscvt to make the drv_data symbol in ndis_driver_data.h a
global so that if_ndis_pci.o and/or if_ndis_pccard.o can see it.
- Obtain the softc pointer from the miniport block by referencing
the PDO rather than a private pointer of our own (nmb_ifp is no
longer used)
- implement IoAttachDeviceToDeviceStack(), IoDetachDevice(),
IoGetAttachedDevice(), IoAllocateDriverObjectExtension(),
IoGetDriverObjectExtension(), IoCreateDevice(), IoDeleteDevice(),
IoAllocateIrp(), IoReuseIrp(), IoMakeAssociatedIrp(), IoFreeIrp(),
IoInitializeIrp()
- fix a few mistakes in the driver_object and device_object definitions
- add a new module, kern_windrv.c, to handle the driver registration
and relocation/dynalinkign duties (which don't really belong in
kern_ndis.c).
- made ndis_block and ndis_chars in the ndis_softc stucture pointers
and modified all references to it
- fixed NdisMRegisterMiniport() and NdisInitializeWrapper() so they
work correctly with the new driver_object mechanism
- changed ndis_attach() to call NdisAddDevice() instead of ndis_load_driver()
(which is now deprecated)
- used ExAllocatePoolWithTag()/ExFreePool() in lookaside list routines
instead of kludged up alloc/free routines
- added kern_windrv.c to sys/modules/ndis/Makefile and files.i386.
attributes in casts (i.e. foo = (__stdcall sometype)bar). This only
happens in two places where we need to set up function pointers, so
work around the problem with some void pointer magic.
USB device support):
- Convert all of my locally chosen function names to their actual
Windows equivalents, where applicable. This is a big no-op change
since it doesn't affect functionality, but it helps avoid a bit
of confusion (it's now a lot easier to see which functions are
emulated Windows API routines and which are just locally defined).
- Turn ndis_buffer into an mdl, like it should have been. The structure
is the same, but now it belongs to the subr_ntoskrnl module.
- Implement a bunch of MDL handling macros from Windows and use them where
applicable.
- Correct the implementation of IoFreeMdl().
- Properly implement IoAllocateMdl() and MmBuildMdlForNonPagedPool().
- Add the definitions for struct irp and struct driver_object.
- Add IMPORT_FUNC() and IMPORT_FUNC_MAP() macros to make formatting
the module function tables a little cleaner. (Should also help
with AMD64 support later on.)
- Fix if_ndis.c to use KeRaiseIrql() and KeLowerIrql() instead of
the previous calls to hal_raise_irql() and hal_lower_irql() which
have been renamed.
The function renaming generated a lot of churn here, but there should
be very little operational effect.
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.
These normally only manifest if the ndis compat module is statically
compiled into a kernel image by way of 'options NDISAPI'.
Submitted by: Dmitri Nikulin
Approved by: wpaul
PR: kern/71449
MFC after: 1 week
- In ntoskrnl_var.h, I had defined compat macros for
ntoskrnl_acquire_spinlock() and ntoskrnl_release_spinlock() but
never used them. This is fortunate since they were stale. Fix them
to work properly. (In Windows/x86 KeAcquireSpinLock() is a macro that
calls KefAcquireSpinLock(), which lives in HAL.dll. To imitate this,
ntoskrnl_acquire_spinlock() is just a macro that calls hal_lock(),
which lives in subr_hal.o.)
- Add macros for ntoskrnl_raise_irql() and ntoskrnl_lower_irql() that
call hal_raise_irql() and hal_lower_irql().
- Use these macros in kern_ndis.c, subr_ndis.c and subr_ntoskrnl.c.
- Along the way, I realised subr_ndis.c:ndis_lock() was not calling
hal_lock() correctly (it was using the FASTCALL2() wrapper when
in reality this routine is FASTCALL1()). Using the
ntoskrnl_acquire_spinlock() fixes this. Not sure if this actually
caused any bugs since hal_lock() would have just ignored what
was in %edx, but it was still bogus.
This hides many of the uses of the FASTCALLx() macros which makes the
code a little cleaner. Should not have any effect on generated object
code, other than the one fix in ndis_lock().
- Give ndiscvt(8) the ability to process a .SYS file directly into
a .o file so that we don't have to emit big messy char arrays into
the ndis_driver_data.h file. This behavior is currently optional, but
may become the default some day.
- Give ndiscvt(8) the ability to turn arbitrary files into .ko files
so that they can be pre-loaded or kldloaded. (Both this and the
previous change involve using objcopy(1)).
- Give NdisOpenFile() the ability to 'read' files out of kernel memory
that have been kldloaded or pre-loaded, and disallow the use of
the normal vn_open() file opening method during bootstrap (when no
filesystems have been mounted yet). Some people have reported that
kldloading if_ndis.ko works fine when the system is running multiuser
but causes a panic when the modile is pre-loaded by /boot/loader. This
happens with drivers that need to use NdisOpenFile() to access
external files (i.e. firmware images). NdisOpenFile() won't work
during kernel bootstrapping because no filesystems have been mounted.
To get around this, you can now do the following:
o Say you have a firmware file called firmware.img
o Do: ndiscvt -f firmware.img -- this creates firmware.img.ko
o Put the firmware.img.ko in /boot/kernel
o add firmware.img_load="YES" in /boot/loader.conf
o add if_ndis_load="YES" and ndis_load="YES" as well
Now the loader will suck the additional file into memory as a .ko. The
phony .ko has two symbols in it: filename_start and filename_end, which
are generated by objcopy(1). ndis_open_file() will traverse each module
in the module list looking for these symbols and, if it finds them, it'll
use them to generate the file mapping address and length values that
the caller of NdisOpenFile() wants.
As a bonus, this will even work if the file has been statically linked
into the kernel itself, since the "kernel" module is searched too.
(ndiscvt(8) will generate both filename.o and filename.ko for you).
- Modify the mechanism used to provide make-pretend FASTCALL support.
Rather than using inline assembly to yank the first two arguments
out of %ecx and %edx, we now use the __regparm__(3) attribute (and
the __stdcall__ attribute) and use some macro magic to re-order
the arguments and provide dummy arguments as needed so that the
arguments passed in registers end up in the right place. Change
taken from DragonflyBSD version of the NDISulator.
- Use the dh_inserted member of the dispatch header in the Windows
timer structure to indicate that the timer has been "inserted into
the timer queue" (i.e. armed via timeout()). Use this as the value
to return to the caller in KeCancelTimer(). Previously, I was using
callout_pending(), but you can't use that with timeout()/untimeout()
without creating a potential race condition.
- Make ntoskrnl_init_timer() just a wrapper around ntoskrnl_init_timer_ex()
(reduces some code duplication).
- Drop Giant when entering if_ndis.c:ndis_tick() and
subr_ntorkrnl.c:ntoskrnl_timercall(). At the moment, I'm forced to
use system callwheel via timeout()/untimeout() to handle timers rather
than the callout API (struct callout is too big to fit inside the
Windows struct KTIMER, so I'm kind of hosed). Unfortunately, all
the callouts in the callwhere are not marked as MPSAFE, so when
one of them fires, it implicitly acquires Giant before invoking the
callback routine (and releases it when it returns). I don't need to
hold Giant, but there's no way to stop the callout code from acquiring
it as long as I'm using timeout()/untimeout(), so for now we cheat
by just dropping Giant right away (and re-acquiring it right before
the routine returns so keep the callout code happy). At some point,
I will need to solve this better, but for now this should be a suitable
workaround.
ntoskrnl_unlocl_dpc().
- hal_raise_irql(), hal_lower_irql() and hal_irql() didn't work right
on SMP (priority inheritance makes things... interesting). For now,
use only two states: DISPATCH_LEVEL (PI_REALTIME) and PASSIVE_LEVEL
(everything else). Tested on a dual PIII box.
- Use ndis_thsuspend() in ndis_sleep() instead of tsleep(). (I added
ndis_thsuspend() and ndis_thresume() to replace kthread_suspend()
and kthread_resume(); the former will preserve a thread's priority
when it wakes up, the latter will not.)
- Change use of tsleep() in ndis_stop_thread() to prevent priority
change on wakeup.
attempting to duplicate Windows spinlocks. Windows spinlocks differ
from FreeBSD spinlocks in the way they block preemption. FreeBSD
spinlocks use critical_enter(), which masks off _all_ interrupts.
This prevents any other threads from being scheduled, but it also
prevents ISRs from running. In Windows, preemption is achieved by
raising the processor IRQL to DISPATCH_LEVEL, which prevents other
threads from preempting you, but does _not_ prevent device ISRs
from running. (This is essentially what Solaris calls dispatcher
locks.) The Windows spinlock itself (kspin_lock) is just an integer
value which is atomically set when you acquire the lock and atomically
cleared when you release it.
FreeBSD doesn't have IRQ levels, so we have to cheat a little by
using thread priorities: normal thread priority is PASSIVE_LEVEL,
lowest interrupt thread priority is DISPATCH_LEVEL, highest thread
priority is DEVICE_LEVEL (PI_REALTIME) and critical_enter() is
HIGH_LEVEL. In practice, only PASSIVE_LEVEL and DISPATCH_LEVEL
matter to us. The immediate benefit of all this is that I no
longer have to rely on a mutex pool.
Now, I'm sure many people will be seized by the urge to criticize
me for doing an end run around our own spinlock implementation, but
it makes more sense to do it this way. Well, it does to me anyway.
Overview of the changes:
- Properly implement hal_lock(), hal_unlock(), hal_irql(),
hal_raise_irql() and hal_lower_irql() so that they more closely
resemble their Windows counterparts. The IRQL is determined by
thread priority.
- Make ntoskrnl_lock_dpc() and ntoskrnl_unlock_dpc() do what they do
in Windows, which is to atomically set/clear the lock value. These
routines are designed to be called from DISPATCH_LEVEL, and are
actually half of the work involved in acquiring/releasing spinlocks.
- Add FASTCALL1(), FASTCALL2() and FASTCALL3() macros/wrappers
that allow us to call a _fastcall function in spite of the fact
that our version of gcc doesn't support __attribute__((__fastcall__))
yet. The macros take 1, 2 or 3 arguments, respectively. We need
to call hal_lock(), hal_unlock() etc... ourselves, but can't really
invoke the function directly. I could have just made the underlying
functions native routines and put _fastcall wrappers around them for
the benefit of Windows binaries, but that would create needless bloat.
- Remove ndis_mtxpool and all references to it. We don't need it
anymore.
- Re-implement the NdisSpinLock routines so that they use hal_lock()
and friends like they do in Windows.
- Use the new spinlock methods for handling lookaside lists and
linked list updates in place of the mutex locks that were there
before.
- Remove mutex locking from ndis_isr() and ndis_intrhand() since they're
already called with ndis_intrmtx held in if_ndis.c.
- Put ndis_destroy_lock() code under explicit #ifdef notdef/#endif.
It turns out there are some drivers which stupidly free the memory
in which their spinlocks reside before calling ndis_destroy_lock()
on them (touch-after-free bug). The ADMtek wireless driver
is guilty of this faux pas. (Why this doesn't clobber Windows I
have no idea.)
- Make NdisDprAcquireSpinLock() and NdisDprReleaseSpinLock() into
real functions instead of aliasing them to NdisAcaquireSpinLock()
and NdisReleaseSpinLock(). The Dpr routines use
KeAcquireSpinLockAtDpcLevel() level and KeReleaseSpinLockFromDpcLevel(),
which acquires the lock without twiddling the IRQL.
- In ndis_linksts_done(), do _not_ call ndis_80211_getstate(). Some
drivers may call the status/status done callbacks as the result of
setting an OID: ndis_80211_getstate() gets OIDs, which means we
might cause the driver to recursively access some of its internal
structures unexpectedly. The ndis_ticktask() routine will call
ndis_80211_getstate() for us eventually anyway.
- Fix the channel setting code a little in ndis_80211_setstate(),
and initialize the channel to IEEE80211_CHAN_ANYC. (The Microsoft
spec says you're not supposed to twiddle the channel in BSS mode;
I may need to enforce this later.) This fixes the problems I was
having with the ADMtek adm8211 driver: we were setting the channel
to a non-standard default, which would cause it to fail to associate
in BSS mode.
- Use hal_raise_irql() to raise our IRQL to DISPATCH_LEVEL when
calling certain miniport routines, per the Microsoft documentation.
I think that's everything. Hopefully, other than fixing the ADMtek
driver, there should be no apparent change in behavior.
which pulls a job off a thread work queue (assuming it hasn't run yet).
This is needed for KeRemoveQueueDpc().
- In subr_ntoskrnl.c, implement KeInsertQueueDpc() and KeRemoveQueueDpc(),
to go with KeInitializeDpc() to round out the API. Also change the
KeTimer implementation to use this API instead of the private
timer callout scheduler. Functionality of the timer API remains
unchanged, but we get a couple new Windows kernel API routines and
more closely imitate the way thing works in Windows. (As of yet
I haven't encountered any drivers that use KeInsertQueueDpc() or
KeRemoveQueueDpc(), but it doesn't hurt to have them.)
when it associates with a net. Because FreeBSD's kstack size is only
2 pages by default, this blows the stack and causes a double fault.
To deal with this, we now create all our kthreads with 8 stack pages.
Also, we now run all timer callouts in the ndis swi thread (since
they would otherwise run in the clock ithread, whose stack is too
small). It happens that the alloca() in this case was occuring within
the interrupt handler, which was already running in the ndis swi
thread, but I want to deal with the callouts too just to be extra
safe.
NOTE: this will only work if you update vm_machdep.c with the change
I just committed. If you don't include this fix, setting the number
of stack pages with kthread_create() has essentially no effect.
are actually layered on top of the KeTimer API in subr_ntoskrnl.c, just
as it is in Windows. This reduces code duplication and more closely
imitates the way things are done in Windows.
- Modify ndis_encode_parm() to deal with the case where we have
a registry key expressed as a hex value ("0x1") which is being
read via NdisReadConfiguration() as an int. Previously, we tried
to decode things like "0x1" with strtol() using a base of 10, which
would always yield 0. This is what was causing problems with the
Intel 2200BG Centrino 802.11g driver: the .inf file that comes
with it has a key called RadioEnable with a value of 0x1. We
incorrectly decoded this value to '0' when it was queried, hence
the driver thought we wanted the radio turned off.
- In if_ndis.c, most drivers don't accept NDIS_80211_AUTHMODE_AUTO,
but NDIS_80211_AUTHMODE_SHARED may not be right in some cases,
so for now always use NDIS_80211_AUTHMODE_OPEN.
NOTE: There is still one problem with the Intel 2200BG driver: it
happens that the kernel stack in Windows is larger than the kernel
stack in FreeBSD. The 2200BG driver sometimes eats up more than 2
pages of stack space, which can lead to a double fault panic.
For the moment, I got things to work by adding the following to
my kernel config file:
options KSTACK_PAGES=8
I'm pretty sure 8 is too big; I just picked this value out of a hat
as a test, and it happened to work, so I left it. 4 pages might be
enough. Unfortunately, I don't think you can dynamically give a
thread a larger stack, so I'm not sure how to handle this short of
putting a note in the man page about it and dealing with the flood
of mail from people who never read man pages.
snprintf() and vsnprintf() in FreeBSD kernel land).
This is needed by the Intel Centrino 2200BG driver. Unfortunately, this
driver still doesn't work right with Project Evil even with this tweak,
but I'm unable to diagnose the problem since I don't have access to a
sample card.
that I added recently:
- When a periodic timer fires, it's automatically re-armed. We must
make sure to re-arm the timer _before_ invoking any caller-supplied
defered procedure call: the DPC may choose to call KeCancelTimer(),
and re-arming the timer after the DPC un-does the effect of the
cancel.
- Fix similar issue with periodic timers in subr_ndis.c.
- When calling KeSetTimer() or KeSetTimerEx(), if the timer is
already pending, untimeout() it first before timeout()ing
it again.
- The old Atheros driver for the 5211 seems to use KeSetTimerEx()
incorrectly, or at the very least in a very strange way that
doesn't quite follow the Microsoft documentation. In one case,
it calls KeSetTimerEx() with a duetime of 0 and a period of 5000.
The Microsoft documentation says that negative duetime values
are relative to the current time and positive values are absolute.
But it doesn't say what's supposed to happen with positive values
that less than the current time, i.e. absolute values that are
in the past.
Lacking any further information, I have decided that timers with
positive duetimes that are in the past should fire right away (or
in our case, after only 1 tick). This also takes care of the other
strange usage in the Atheros driver, where the duetime is
specified as 500000 and the period is 50. I think someone may
have meant to use -500000 and misinterpreted the documentation.
- Also modified KeWaitForSingleObject() and KeWaitForMultipleObjects()
to make the same duetime adjustment, since they have the same rules
regarding timeout values.
- Cosmetic: change name of 'timeout' variable in KeWaitForSingleObject()
and KeWaitForMultipleObjects() to 'duetime' to avoid senseless
(though harmless) overlap with timeout() function name.
With these fixes, I can get the 5211 card to associate properly with
my adhoc net using driver AR5211.SYS version 2.4.1.6.
along with KeInitializeTimerEx(), KeSetTimer(), KeSetTimerEx(),
KeCancelTimer(), KeReadStateTimer() and KeInitializeDpc(). I don't
know for certain that these will make the Atheros driver happy since
I don't have the card/driver combo needed to test it, but these are
fairly independent so they shouldn't break anything else.
- Debugger() is present even in kernels without options DDB, so no
conditional compilation is necessary (pointed out by bde).
- Remove the extra km_acquirecnt member that I added to struct kmutant
and embed it within an unused portion of the structure instead, so that
we don't make the structure larger than it's defined to be in Windows.
I don't know what crack I was smoking when I decided it was ok to do
this, but it's worn off now.
routines to guard against problems caused by (possibly) buggy drivers.
The RealTek 8180 wireless driver calls NdisFreeBuffer() to release
some of its buffers _after_ it's already called NdisFreeBufferPool()
to destroy the pool to which the buffers belong. In our implementation,
this error causes NdisFreeBuffer() to touch stale heap memory.
If you are running a release kernel, and hence have INVARIANTS et al
turned off, it turns out nothing happens. But if you're using a
development kernel config with INVARIANTS on, the malloc()/free()
sanity checks will scribble over the pool memory with 0xdeadc0de
once it's released so that any attempts to touch it will cause a
trap, and indeed this is what happens. It happens that I run 5.2-RELEASE
on my laptop, so when I tested the rtl8180.sys driver, it worked fine
for me, but people trying to run it with development systems checked
out or cvsupped from -current would get a page fault on driver load.
I can't find any reason why the NDISulator would cause the RealTek
driver to do the NdisFreeBufferPool() prematurely, and the same driver
obviously works with Windows -- or at least, it doesn't cause a crash:
the Microsoft documentation for NdisFreeBufferPool() says that failing
to return all buffers to the pool before calling NdisFreeBufferPool()
causes a memory leak.
I've written to my contacts at RealTek asking them to check if this
is indeed a bug in their driver. In the meantime, these new sanity checks
will catch this problem and issue a warning rather than causing a trap.
The trick is to keep a count of outstanding buffers for each buffer pool,
and if the driver tries to call NdisFreeBufferPool() while there are still
buffers outstanding, we mark the pool for deletion and then defer
destroying it until after the last buffer has been reclaimed.
is set, since some drivers with debug info can be very chatty.
Also implement DbgBreakPoint(), which is the Windows equivalent of
Debugger(). Unfortunately, this forces subr_ntoskrnl.c to include
opt_ddb.h.
- When adding new waiting threads to the waitlist for an object,
use INSERT_LIST_TAIL() instead of INSERT_LIST_HEAD() so that new
waiters go at the end of the list instead of the beginning. When we
wake up a synchronization object, only the first waiter is awakened,
and this needs to be the first thread that actually waited on the object.
- Correct missing semicolon in INSERT_LIST_TAIL() macro.
- Implement lookaside lists correctly. Note that the Am1771 driver
uses lookaside lists to manage shared memory (i.e. DMAable) buffers
by specifying its own alloc and free routines. The Microsoft documentation
says you should avoid doing this, but apparently this did not deter
the developers at AMD from doing it anyway.
With these changes (which are the result of two straight days of almost
non-stop debugging), I think I finally have the object/thread handling
semantics implemented correctly. The Am1771 driver no longer crashes
unexpectedly during association or bringing the interface up.
802.11b chipset work. This chip is present on the SMC2602W version 3
NIC, which is what was used for testing. This driver creates kernel
threads (12 of them!) for various purposes, and required the following
routines:
PsCreateSystemThread()
PsTerminateSystemThread()
KeInitializeEvent()
KeSetEvent()
KeResetEvent()
KeInitializeMutex()
KeReleaseMutex()
KeWaitForSingleObject()
KeWaitForMultipleObjects()
IoGetDeviceProperty()
and several more. Also, this driver abuses the fact that NDIS events
and timers are actually Windows events and timers, and uses NDIS events
with KeWaitForSingleObject(). The NDIS event routines have been rewritten
to interface with the ntoskrnl module. Many routines with incorrect
prototypes have been cleaned up.
Also, this driver puts jobs on the NDIS taskqueue (via NdisScheduleWorkItem())
which block on events, and this interferes with the operation of
NdisMAllocateSharedMemoryAsync(), which was also being put on the
NDIS taskqueue. To avoid the deadlock, NdisMAllocateSharedMemoryAsync()
is now performed in the NDIS SWI thread instead.
There's still room for some cleanups here, and I really should implement
KeInitializeTimer() and friends.
the definitions for NDIS_BUS_SPACE_IO and NDIS_BUS_SPACE_MEM logically
belong in hal_var.h. At least, that's my story, and I'm sticking to it.
Also, remove definition of __stdcall from if_ndis.c now that it's pulled
in from pe_var.h.
unexpected interrupts. If an interrupt is triggered and we're not
finished initializing yet, bail. If we have finished initializing,
but IFF_UP isn't set yet, drain the interrupt with ndis_intr() or
ndis_disable_intr() as appropriate, then return _without_ scheduling
ndis_intrtask().
In kern_ndis.c:ndis_load_driver() only relocate/dynalink a given driver
image once. Trying to relocate an image that's already been relocated
will trash the image. We poison a part of the image header that we
don't otherwise need with a magic value to indicate it's already been
fixed up. This fixes the case where there are multiple units of the
same kind of device.
these add support for listing BSSIDs via wicontrol -l. I added code
to call OID_802_11_BSSID_LIST_SCAN to allow scanning for any nearby
wirelsss nets.
Convert from using individual mutexes to a mutex pool, created in
subr_ndis.c. This deals with the problem of drivers creating locks
in their DriverEntry() routines which might get trashed later.
Put some messages under IFF_DEBUG.
in subr_ndis and subr_ntoskrnl. This is faster and avoids potential
LOR whinage from witness (an LOR couldn't happen with the old code
since the interlocked inc/dec routines could not sleep with a lock
held, but this will keep witness happy and it's more efficient
anyway. I think.)
the RT_MESSAGETABLE resources that some driver binaries have.
This allows us to print error messages in ndis_syslog().
- Correct the implementation of InterlockedIncrement() and
InterlockedDecrement() -- they return uint32_t, not void.
- Correct the declarations of the 64-bit arithmetic shift
routines in subr_ntoskrnl.c (_allshr, allshl, etc...). These
do not follow the _stdcall convention: instead, they appear
to be __attribute__((regparm(3)).
- Change the implementation of KeInitializeSpinLock(). There is
no complementary KeFreeSpinLock() function, so creating a new
mutex on each call to KeInitializeSpinLock() leaks resources
when a driver is unloaded. For now, KeInitializeSpinLock()
returns a handle to the ntoskrnl interlock mutex.
- Use a driver's MiniportDisableInterrupt() and MiniportEnableInterrupt()
routines if they exist. I'm not sure if I'm doing this right
yet, but at the very least this shouldn't break any currently
working drivers, and it makes the Intel PRO/1000 driver work.
- In ndis_register_intr(), save some state that might be needed
later, and save a pointer to the driver's interrupt structure
in the ndis_miniport_block.
- Save a pointer to the driver image for use by ndis_syslog()
when it calls pe_get_message().
the NTx86 section decoration).
subr_ndis.c: correct the behavior of ndis_query_resources(): if the
caller doesn't provide enough space to return the resources, tell it
how much it needs to provide and return an error.
subr_hal.c & subr_ntoskrnl.c: implement/stub a bunch of new routines;
ntoskrnl:
KefAcquireSpinLockAtDpcLevel
KefReleaseSpinLockFromDpcLevel
MmMapLockedPages
InterlockedDecrement
InterlockedIncrement
IoFreeMdl
KeInitializeSpinLock
HAL:
KfReleaseSpinLock
KeGetCurrentIrql
KfAcquireSpinLock
Lastly, correct spelling of "_aullshr" in the ntoskrnl functable.
peter and jhb: use __volatile__ to prevent gcc from possibly reordering
code, use a null inline instruction instead of a no-op movl (I would
have done this myself if I knew it was allowed) and combine two register
assignments into a single asm statement.
- if_ndis.c: set the NDIS_STATUS_PENDING flag on all outgoing packets
in ndis_start(), make the resource allocation code a little smarter
about how it selects the altmem range, correct a lock order reversal
in ndis_tick().
- Fix ndis_time().
- Implement NdisGetSystemUpTime().
- Implement RtlCopyUnicodeString() and RtlUnicodeStringToAnsiString().
- In ndis_getstate_80211(), use sc->ndis_link to determine connect
status.
Submitted by: Brian Feldman <green@freebsd.org>
- fix ndis_time() so that it returns a time based on the proper
epoch (wacky though it may be)
- implement NdisInitializeString() and NdisFreeString(), and add
stub for NdisMRemoveMiniport()
ntoskrnl_var.h:
- add missing member to the general_lookaside struct (gl_listentry)
subr_ntoskrnl.c:
- Fix arguments to the interlocked push/pop routines: 'head' is an
slist_header *, not an slist_entry *
- Kludge up _fastcall support for the push/pop routines. The _fastcall
convention is similar to _stdcall, except the first two available
DWORD-sized arguments are passed in %ecx and %edx, respectively.
One kludge for this __attribute__ ((regparm(3))), however this
isn't entirely right, as it assumes %eax, %ecx and %edx will be
used (regparm(2) assumes %eax and %edx). Another kludge is to
declare the two fastcall-ed args as local register variables and
explicitly assign them to %ecx and %edx, but experimentation showed
that gcc would not guard %ecx and %edx against being clobbered.
Thus, I came up with a 3rd kludge, which is to use some inline
assembly of the form:
void *arg1;
void *arg2;
__asm__("movl %%ecx, %%ecx" : "=c" (arg1));
__asm__("movl %%edx, %%edx" : "=d" (arg2));
This lets gcc know that we're going to reference %ecx and %edx and
that it should make an effort not to let it get trampled. This wastes
an instruction (movl %reg, %reg is a no-op) but insures proper
behavior. It's possible there's a better way to do this though:
this is the first time I've used inline assembler in this fashion.
The above fixes to ntoskrnl_var.h an subr_ntoskrnl.c make lookaside
lists work for the two drivers I have that use them, one of which
is an NDIS 5.0 miniport and another which is 5.1.
subr_ndis.c: NdisGetCurrentSystemTime() which, according to the
Microsoft documentation returns "the number of 100 nanosecond
intervals since January 1, 1601." I have no idea what's so special
about that epoch or why they chose 100 nanosecond ticks. I don't
know the proper offset to convert nanotime() from the UNIX epoch
to January 1, 1601, so for now I'm just doing the unit convertion
to 100s of nanoseconds.
subr_ntoskrnl.c: memcpy(), memset(), ExInterlockedPopEntrySList(),
ExInterlockedPushEntrySList().
The latter two are different from InterlockedPopEntrySList()
and InterlockedPushEntrySList() in that they accept a spinlock to
hold while executing, whereas the non-Ex routines use a lock
internal to ntoskrnl. I also modified ExInitializePagedLookasideList()
and ExInitializeNPagedLookasideList() to initialize mutex locks
within the lookaside structures. It seems that in NDIS 5.0,
the lookaside allocate/free routines ExInterlockedPopEntrySList()
and ExInterlockedPushEntrySList(), which require the use of the
per-lookaside spinlock, whereas in NDIS 5.1, the per-lookaside
spinlock is deprecated. We need to support both cases.
Note that I appear to be doing something wrong with
ExInterlockedPopEntrySList() and ExInterlockedPushEntrySList():
they don't appear to obtain proper pointers to their arguments,
so I'm probably doing something wrong in terms of their calling
convention (they're declared to be FASTCALL in Widnows, and I'm
not sure what that means for gcc). It happens that in my stub
lookaside implementation, they don't need to do any work anyway,
so for now I've hacked them to always return NULL, which avoids
corrupting the stack. I need to do this right though.
Yes, it's what you think it is. Yes, you should run away now.
This is a special compatibility module for allowing Windows NDIS
miniport network drivers to be used with FreeBSD/x86. This provides
_binary_ NDIS compatibility (not source): you can run NDIS driver
code, but you can't build it. There are three main parts:
sys/compat/ndis: the NDIS compat API, which provides binary
compatibility functions for many routines in NDIS.SYS, HAL.dll
and ntoskrnl.exe in Windows (these are the three modules that
most NDIS miniport drivers use). The compat module also contains
a small PE relocator/dynalinker which relocates the Windows .SYS
image and then patches in our native routines.
sys/dev/if_ndis: the if_ndis driver wrapper. This module makes
use of the ndis compat API and can be compiled with a specially
prepared binary image file (ndis_driver_data.h) containing the
Windows .SYS image and registry key information parsed out of the
accompanying .INF file. Once if_ndis.ko is built, it can be loaded
and unloaded just like a native FreeBSD kenrel module.
usr.sbin/ndiscvt: a special utility that converts foo.sys and foo.inf
into an ndis_driver_data.h file that can be compiled into if_ndis.o.
Contains an .inf file parser graciously provided by Matt Dodd (and
mercilessly hacked upon by me) that strips out device ID info and
registry key info from a .INF file and packages it up with a binary
image array. The ndiscvt(8) utility also does some manipulation of
the segments within the .sys file to make life easier for the kernel
loader. (Doing the manipulation here saves the kernel code from having
to move things around later, which would waste memory.)
ndiscvt is only built for the i386 arch. Only files.i386 has been
updated, and none of this is turned on in GENERIC. It should probably
work on pc98. I have no idea about amd64 or ia64 at this point.
This is still a work in progress. I estimate it's about %85 done, but
I want it under CVS control so I can track subsequent changes. It has
been tested with exactly three drivers: the LinkSys LNE100TX v4 driver
(Lne100v4.sys), the sample Intel 82559 driver from the Windows DDK
(e100bex.sys) and the Broadcom BCM43xx wireless driver (bcmwl5.sys). It
still needs to have a net80211 stuff added to it. To use it, you would
do something like this:
# cd /sys/modules/ndis
# make; make load
# cd /sys/modules/if_ndis
# ndiscvt -i /path/to/foo.inf -s /path/to/foo.sys -o ndis_driver_data.h
# make; make load
# sysctl -a | grep ndis
All registry keys are mapped to sysctl nodes. Sometimes drivers refer
to registry keys that aren't mentioned in foo.inf. If this happens,
the NDIS API module creates sysctl nodes for these keys on the fly so
you can tweak them.
An example usage of the Broadcom wireless driver would be:
# sysctl hw.ndis0.EnableAutoConnect=1
# sysctl hw.ndis0.SSID="MY_SSID"
# sysctl hw.ndis0.NetworkType=0 (0 for bss, 1 for adhoc)
# ifconfig ndis0 <my ipaddr> netmask 0xffffff00 up
Things to be done:
- get rid of debug messages
- add in ndis80211 support
- defer transmissions until after a status update with
NDIS_STATUS_CONNECTED occurs
- Create smarter lookaside list support
- Split off if_ndis_pci.c and if_ndis_pccard.c attachments
- Make sure PCMCIA support works
- Fix ndiscvt to properly parse PCMCIA device IDs from INF files
- write ndisapi.9 man page
