Commit Graph

1056 Commits

Author SHA1 Message Date
jhb
d7eebc79f5 Add Giant around linux_getcwd_common() in linux_getcwd().
Approved by:	re (scottl)
2005-07-09 12:34:49 +00:00
jhb
8816876fa9 Add missing locking to linux_connect() so that it can be marked MP safe:
- Conditionally grab Giant around the EISCONN hack at the end based on
  debug.mpsafenet.
- Protect access to so_emuldata via SOCK_LOCK.

Reviewed by:	rwatson
Approved by:	re (scottl)
2005-07-09 12:26:22 +00:00
rik
d732ff5ca2 Use implicit type cast for ->k_lock to fix compilation of ndis
as a part of the GENERIC kernel with INVARIANT* and WITNESS*
turned off.
(For non GENERIC kernel KTR and MUTEX_PROFILING should be also
off).

Submitted by:	Eygene A. Ryabinkin <rea at rea dot mbslab dot kiae dot ru>
Approved by:	re (scottl)
PR:		81767
2005-07-08 18:36:59 +00:00
jhb
89c65bc296 Lock Giant in svr4_add_socket() so that the various svr4_*stat() calls
can be marked MP safe as this is the only part of them that is not
already MP safe.

Approved by:	re (scottl)
2005-07-07 19:27:29 +00:00
jhb
f2ca5e0f59 Remove an unused syscallarg() macro leftover from this code's origins in
NetBSD.

Approved by:	re (scottl)
2005-07-07 19:26:43 +00:00
jhb
64250ecf1e Rototill this file so that it actually compiles. It doesn't do anything
in the build still due to some #undef's in svr4.h, but if you hack around
that and add some missing entries to syscalls.master, then this file will
now compile.  The changes involved proc -> thread, using FreeBSD syscall
names instead of NetBSD, and axeing syscallarg() and retval arguments.

Approved by:	re (scottl)
2005-07-07 19:25:47 +00:00
jhb
d7828dd231 Fix the computation of uptime for linux_sysinfo(). Before it was returning
the uptime in seconds mod 60 which wasn't very useful.

Approved by:	re (scottl)
2005-07-07 19:17:55 +00:00
jhb
f962c71215 Regenerate.
Approved by:	re (scottl)
2005-07-07 18:20:38 +00:00
jhb
cf15cbb1b6 - Add two new system calls: preadv() and pwritev() which are like readv()
and writev() except that they take an additional offset argument and do
  not change the current file position.  In SAT speak:
  preadv:readv::pread:read and pwritev:writev::pwrite:write.
- Try to reduce code duplication some by merging most of the old
  kern_foov() and dofilefoo() functions into new dofilefoo() functions
  that are called by kern_foov() and kern_pfoov().  The non-v functions
  now all generate a simple uio on the stack from the passed in arguments
  and then call kern_foov().  For example, read() now just builds a uio and
  calls kern_readv() and pwrite() just builds a uio and calls kern_pwritev().

PR:		kern/80362
Submitted by:	Marc Olzheim marcolz at stack dot nl (1)
Approved by:	re (scottl)
MFC after:	1 week
2005-07-07 18:17:55 +00:00
peter
921b3c5ee4 Jumbo-commit to enhance 32 bit application support on 64 bit kernels.
This is good enough to be able to run a RELENG_4 gdb binary against
a RELENG_4 application, along with various other tools (eg: 4.x gcore).
We use this at work.

ia32_reg.[ch]: handle the 32 bit register file format, used by ptrace,
	procfs and core dumps.
procfs_*regs.c: vary the format of proc/XXX/*regs depending on the client
	and target application.
procfs_map.c: Don't print a 64 bit value to 32 bit consumers, or their
	sscanf fails.  They expect an unsigned long.
imgact_elf.c: produce a valid 32 bit coredump for 32 bit apps.
sys_process.c: handle 32 bit consumers debugging 32 bit targets.  Note
	that 64 bit consumers can still debug 32 bit targets.

IA64 has got stubs for ia32_reg.c.

Known limitations: a 5.x/6.x gdb uses get/setcontext(), which isn't
implemented in the 32/64 wrapper yet.  We also make a tiny patch to
gdb pacify it over conflicting formats of ld-elf.so.1.

Approved by:	re
2005-06-30 07:49:22 +00:00
jhb
62d0fed7ec - Change the commented out freebsd32_xxx() example to use kern_xxx() along
with a single copyin() + translate and translate + copyout() rather than
  using the stackgap.
- Remove implementation of the stackgap for freebsd32 since it is no longer
  used for that compat ABI.

Approved by:	re (scottl)
2005-06-29 15:16:20 +00:00
jhb
0a8b4194dc Correct the amount of data to allocate in these local copies of
exec_copyin_strings() to catch up to rev 1.266 of kern_exec.c.  This fixes
panics on amd64 with compat binaries since exec_free_args() was freeing
more memory than these functions were allocating and the mismatch could
cause memory to be freed out from under other concurrent execs.

Approved by:	re (scottl)
2005-06-24 17:41:28 +00:00
pjd
a99a8a69bd Actually only protect mount-point if security.jail.enforce_statfs is set to 2.
If we don't return statistics about requested file systems, system tools
may not work correctly or at all.

Approved by:	re (scottl)
2005-06-23 22:13:29 +00:00
pjd
be79126844 Do not allocate memory based on not-checked argument from userland.
It can be used to panic the kernel by giving too big value.
Fix it by moving allocation and size verification into kern_getfsstat().
This even simplifies kern_getfsstat() consumers, but destroys symmetry -
memory is allocated inside kern_getfsstat(), but has to be freed by the
caller.

Found by:	FreeBSD Kernel Stress Test Suite: http://www.holm.cc/stress/
Reported by:	Peter Holm <peter@holm.cc>
2005-06-11 14:58:20 +00:00
brooks
567ba9b00a Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
 - Struct arpcom is no longer referenced in normal interface code.
   Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
   To enforce this ac_enaddr has been renamed to _ac_enaddr.
 - The second argument to ether_ifattach is now always the mac address
   from driver private storage rather than sometimes being ac_enaddr.

Reviewed by:	sobomax, sam
2005-06-10 16:49:24 +00:00
pjd
47f442bcb9 Rename sysctl security.jail.getfsstatroot_only to security.jail.enforce_statfs
and extend its functionality:

value	policy
0	show all mount-points without any restrictions
1	show only mount-points below jail's chroot and show only part of the
	mount-point's path (if jail's chroot directory is /jails/foo and
	mount-point is /jails/foo/usr/home only /usr/home will be shown)
2	show only mount-point where jail's chroot directory is placed.

Default value is 2.

Discussed with:	rwatson
2005-06-09 18:49:19 +00:00
pjd
3af857a21a Avoid code duplication in serval places by introducing universal
kern_getfsstat() function.

Obtained from:	jhb
2005-06-09 17:44:46 +00:00
sobomax
307c6bb149 Properly convert FreeBSD priority values into Linux values in the
getpriority(2) syscall.

PR:		kern/81951
Submitted by:	Andriy Gapon <avg@icyb.net.ua>
2005-06-08 20:41:28 +00:00
ps
bac0ce72d5 Wrap copyin/copyout for kevent so the 32bit wrapper does not have
to malloc nchanges * sizeof(struct kevent) AND/OR nevents *
sizeof(struct kevent) on every syscall.

Glanced at by:	peter, jmg
Obtained from:	Yahoo!
MFC after:	2 weeks
2005-06-03 23:15:01 +00:00
rwatson
5010364761 Rebuild generated system call definition files following the addition of
the audit event field to the syscalls.master file format.

Submitted by:	wsalamon
Obtained from:	TrustedBSD Project
2005-05-30 15:20:21 +00:00
rwatson
370e72b242 Introduce a new field in the syscalls.master file format to hold the
audit event identifier associated with each system call, which will
be stored by makesyscalls.sh in the sy_auevent field of struct sysent.
For now, default the audit identifier on all system calls to AUE_NULL,
but in the near future, other BSM event identifiers will be used.  The
mapping of system calls to event identifiers is many:one due to
multiple system calls that map to the same end functionality across
compatibility wrappers, ABI wrappers, etc.

Submitted by:	wsalamon
Obtained from:	TrustedBSD Project
2005-05-30 15:09:18 +00:00
nyan
0fce92f5c4 Remove bus_{mem,p}io.h and related code for a micro-optimization on i386
and amd64.  The optimization is a trivial on recent machines.

Reviewed by:	-arch (imp, marcel, dfr)
2005-05-29 04:42:30 +00:00
pjd
311d5e1182 Remove (now) unused argument 'td' from bsd_to_linux_statfs(). 2005-05-27 19:25:39 +00:00
ps
5f0ea7b68e Copyout to userland if kern_sigaction succeeds 2005-05-24 17:52:14 +00:00
pjd
abf2289872 The code is under '#ifdef not_that_way', but anyway:
- Add missing prison_check_mount() check.
2005-05-22 22:30:31 +00:00
pjd
a6e0e217b2 If we need to hide fsid, kern_statfs()/kern_fstatfs() will do it for us,
so do not duplicate the code in cvtstatfs().
Note, that we now need to clear fsid in freebsd4_getfsstat().

This moves all security related checks from functions like cvtstatfs()
and will allow to add more security related stuff (like statfs(2), etc.
protection for jails) a bit easier.
2005-05-22 21:52:30 +00:00
wpaul
df85175aeb Missed kern_windrv.c in the last checkin. 2005-05-20 04:01:36 +00:00
wpaul
29dcab8107 Deal with a few bootstrap issues:
We can't call KeFlushQueuedDpcs() during bootstrap (cold == 1), since
the flush operation sleeps to wait for completion, and we can't sleep
here (clowns will eat us).

On an i386 SMP system, if we're loaded/probed/attached during bootstrap,
smp_rendezvous() won't run us anywhere except CPU 0 (since the other CPUs
aren't launched until later), which means we won't be able to set up
the GDTs anywhere except CPU 0. To deal with this case, ctxsw_utow()
now checks to see if the TID for the current processor has been properly
initialized and sets up the GTD for the current CPU if not.

Lastly, in if_ndis.c:ndis_shutdown(), do an ndis_stop() to insure we
really halt the NIC and stop interrupts from happening.

Note that loading a driver during bootstrap is, unfortunately, kind of
a hit or miss sort of proposition. In Windows, the expectation is that
by the time a given driver's MiniportInitialize() method is called,
the system is already in 'multiuser' state, i.e. it's up and running
enough to support all the stuff specified in the NDIS API, which includes
the underlying OS-supplied facilities it implicitly depends on, such as
having all CPUs running, having the DPC queues initialized, WorkItem
threads running, etc. But in UNIX, a lot of that stuff won't work during
bootstrap. This causes a problem since we need to call MiniportInitialize()
at least once during ndis_attach() in order to find out what kind of NIC
we have and learn its station address.

What this means is that some cards just plain won't work right if
you try to pre-load the driver along with the kernel: they'll only be
probed/attach correctly if the driver is kldloaded _after_ the system
has reached multiuser. I can't really think of a way around this that
would still preserve the ability to use an NDIS device for diskless
booting.
2005-05-20 04:00:50 +00:00
wpaul
cb815ff30f In ndis_halt_nic(), invalidate the miniportadapterctx early to try and
prevent anything from making calls to the NIC while it's being shut down.
This is yet another attempt to stop things like mdnsd from trying to
poke at the card while it's not properly initialized and panicking
the system.

Also, remove unneeded debug message from if_ndis.c.
2005-05-20 02:35:43 +00:00
wpaul
8e4107ff8f Fix some of the things I broke so that the SMC2602W (AMD Am1772) driver
works again.

This driver uses NdisScheduleWorkItem(), and we have to take special steps
to insure that its workitems don't collide with any of the other workitems
used by the NDISulator. In particular, if one of the driver's work jobs
blocks, it can prevent NdisMAllocateSharedMemoryAsync() from completing
when expected.

The original hack to fix this was to have NdisMAllocateSharedMemoryAsync()
defer its work to the DPC queue instead of the general task queue. To
fix it now, I decided to add some additional workitem threads. (There's
supposed to be a pool of worker threads in Windows anyway.) Currently,
there are 4. There should be at least 2. One is reserved for the legacy
ExQueueWorkItem() API, while the others are used in round-robin by the
IoQueueWorkItem() API. NdisMAllocateSharedMemoryAsync() uses the latter
API while NdisScheduleWorkItem() uses the former, so the deadlock is
avoided.

Fixed NdisMRegisterDevice()/NdisMDeregisterDevice() to work a little
more sensibly with the new driver_object/device_object framework. It
doesn't really register a working user-mode interface, but the existing
code was completely wrong for the new framework.

Fixed a couple of bugs dealing with the cancellation of events and
DPCs. When cancelling an event that's still on the timer queue (i.e.
hasn't expired yet), reset dh_inserted in its dispatch header to FALSE.
Previously, it was left set to TRUE, which would make a cancelled
timer appear to have not been cancelled. Also, when removing a DPC
from a queue, reset its list pointers, otherwise a cancelled DPC
might mistakenly be treated as still pending.

Lastly, fix the behavior of ntoskrnl_wakeup() when dealing with
objects that have nobody waiting on them: sync event objects get
their signalled state reset to FALSE, but notification objects
should still be set to TRUE.
2005-05-19 04:44:26 +00:00
wpaul
3e9d45596e Remove harmless bit of leftover debug code. 2005-05-16 15:44:41 +00:00
wpaul
0228d4cac8 Correct some problems with workitem usage. NdisScheduleWorkItem() does
not use exactly the same workitem sturcture as ExQueueWorkItem() like
I originally thought it did.
2005-05-16 15:29:21 +00:00
wpaul
09647ee931 Add support for NdisMEthIndicateReceive() and MiniportTransferData().
The Ralink RT2500 driver uses this API instead of NdisMIndicateReceivePacket().

Drivers use NdisMEthIndicateReceive() when they know they support
802.3 media and expect to hand their packets only protocols that want
to deal with that particular media type. With this API, the driver does
not manage its own NDIS_PACKET/NDIS_BUFFER structures. Instead, it
lets bound protocols have a peek at the data, and then they supply
an NDIS_PACKET/NDIS_BUFFER combo to the miniport driver, into which
it copies the packet data.

Drivers use NdisMIndicateReceivePacket() to allow their packets to
be read by any protocol, not just those bound to 802.3 media devices.

To make this work, we need an internal pool of NDIS_PACKETS for
receives. Currently, we check to see if the driver exports a
MiniportTransferData() method in its characteristics structure,
and only allocate the pool for drivers that have this method.

This should allow the RT2500 driver to work correctly, though I
still have to fix ndiscvt(8) to parse its .inf file properly.

Also, change kern_ndis.c:ndis_halt_nic() to reap timers before
acquiring NDIS_LOCK(), since the reaping process might entail sleeping
briefly (and we can't sleep with a lock held).
2005-05-15 04:27:59 +00:00
wpaul
51b4d0ab71 More fixes for multibus drivers. When calling out to the match
function in if_ndis_pci.c and if_ndis_pccard.c, provide the bustype
too so the stubs can ignore devlists that don't concern them.
2005-05-08 23:19:20 +00:00
wpaul
ebc77ad893 Fix support for Windows drivers that support both PCI and PCMCIA devices at
the same time.

Fix if_ndis_pccard.c so that it sets sc->ndis_dobj and sc->ndis_regvals.

Correct IMPORT_SFUNC() macros for the READ_PORT_BUFFER_xxx() routines,
which take 3 arguments, not 2.

This fixes it so that the Windows driver for my Cisco Aironet 340 PCMCIA
card works again. (Yes, I know the an(4) driver supports this card natively,
but it's the only PCMCIA device I have with a Windows XP driver.)
2005-05-08 23:07:51 +00:00
wpaul
36f8fdfd36 Correct the patch table entries for the 64-bit intrinsic math
routines (_alldiv(), _allmul(), _alludiv(), _aullmul(), etc...)
that use the _stdcall calling convention.

These routines all take two arguments, but the arguments are 64 bits wide.
On the i386 this means they each consume two 32-bit slots on the stack.
Consequently, when we specify the argument count in the IMPORT_SFUNC()
macro, we have to lie and claim there are 4 arguments instead of two.
This will cause the resulting i386 assembly wrapper to push the right
number of longwords onto the stack.

This fixes a crash I discovered with the RealTek 8180 driver, which
uses these routines a lot during initialization.
2005-05-08 09:16:33 +00:00
wpaul
d2ae5c8a71 Cast 64 bit quantity to uintmax_t to print it with %jx. This is
technically a no-op since uintmax_t is uint64_t on all currently
supported architectures, but we should use an explicit cast instead
of depending on this obscure coincidence.
2005-05-05 22:33:06 +00:00
wpaul
819bac8d1e Use %jx instead of %qx to silence compiler warning on amd64. 2005-05-05 15:56:41 +00:00
wpaul
077b71e0fa Avoid sleeping with mutex held in kern_ndis.c.
Remove unused fields from ndis_miniport_block.

Fix a bug in KeFlushQueuedDpcs() (we weren't calculating the kq pointer
correctly).

In if_ndis.c, clear the IFF_RUNNING flag before calling ndis_halt_nic().

Add some guards in kern_ndis.c to avoid letting anyone invoke ndis_get_info()
or ndis_set_info() if the NIC isn't fully initialized. Apparently, mdnsd
will sometimes try to invoke the ndis_ioctl() routine at exactly the
wrong moment (to futz with its multicast filters) when the interface
comes up, and can trigger a crash unless we guard against it.
2005-05-05 06:14:59 +00:00
wpaul
bb2b136388 Remove extranaous free() of ASCII filename from NdisOpenFile().
Oh, one additional change I forgot to mention in the last commit:
NdisOpenFile() was broken in the case for firmware files that were
pre-loaded as modules. When searching for the module in NdisOpenFile(),
we would match against a symbol name, which would contain the string
we were looking for, then save a pointer to the linker file handle.
Later, in NdisMapFile(), we would refer to the filename hung off
this handle when trying to find the starting address symbol. Only
problem is, this filename is different from the embedded symbol
name we're searching for, so the mapping would fail. I found this
problem while testing the AirGo driver, which requires a small
firmware file.
2005-05-05 04:16:13 +00:00
wpaul
e9bace5ba1 This commit makes a bunch of changes, some big, some not so big.
- Remove the old task threads from kern_ndis.c and reimplement them in
  subr_ntoskrnl.c, in order to more properly emulate the Windows DPC
  API. Each CPU gets its own DPC queue/thread, and each queue can
  have low, medium and high importance DPCs. New APIs implemented:
  KeSetTargetProcessorDpc(), KeSetImportanceDpc() and KeFlushQueuedDpcs().
  (This is the biggest change.)

- Fix a bug in NdisMInitializeTimer(): the k_dpc pointer in the
  nmt_timer embedded in the ndis_miniport_timer struct must be set
  to point to the DPC, also embedded in the struct. Failing to do
  this breaks dequeueing of DPCs submitted via timers, and in turn
  breaks cancelling timers.

- Fix a bug in KeCancelTimer(): if the timer is interted in the timer
  queue (i.e. the timeout callback is still pending), we have to both
  untimeout() the timer _and_ call KeRemoveQueueDpc() to nuke the DPC
  that might be pending. Failing to do this breaks cancellation of
  periodic timers, which always appear to be inserted in the timer queue.

- Make use of the nmt_nexttimer field in ndis_miniport_timer: keep a
  queue of pending timers and cancel them all in ndis_halt_nic(), prior
  to calling MiniportHalt(). Also call KeFlushQueuedDpcs() to make sure
  any DPCs queued by the timers have expired.

- Modify NdisMAllocateSharedMemory() and NdisMFreeSharedMemory() to keep
  track of both the virtual and physical addresses of the shared memory
  buffers that get handed out. The AirGo MIMO driver appears to have a bug
  in it: for one of the segments is allocates, it returns the wrong
  virtual address. This would confuse NdisMFreeSharedMemory() and cause
  a crash. Why it doesn't crash Windows too I have no idea (from reading
  the documentation for NdisMFreeSharedMemory(), it appears to be a violation
  of the API).

- Implement strstr(), strchr() and MmIsAddressValid().

- Implement IoAllocateWorkItem(), IoFreeWorkItem(), IoQueueWorkItem() and
  ExQueueWorkItem(). (This is the second biggest change.)

- Make NdisScheduleWorkItem() call ExQueueWorkItem(). (Note that the
  ExQueueWorkItem() API is deprecated by Microsoft, but NDIS still uses
  it, since NdisScheduleWorkItem() is incompatible with the IoXXXWorkItem()
  API.)

- Change if_ndis.c to use the NdisScheduleWorkItem() interface for scheduling
  tasks.

With all these changes and fixes, the AirGo MIMO driver for the Belkin
F5D8010 Pre-N card now works. Special thanks to Paul Robinson
(paul dawt robinson at pwermedia dawt net) for the loan of a card
for testing.
2005-05-05 03:56:09 +00:00
jeff
f869be5c72 - Pass the ISOPEN flag to namei so filesystems will know we're about to
open them or otherwise access the data.
2005-04-27 09:05:19 +00:00
wpaul
b493dd59e2 Throw the switch on the new driver generation/loading mechanism. From
here on in, if_ndis.ko will be pre-built as a module, and can be built
into a static kernel (though it's not part of GENERIC). Drivers are
created using the new ndisgen(8) script, which uses ndiscvt(8) under
the covers, along with a few other tools. The result is a driver module
that can be kldloaded into the kernel.

A driver with foo.inf and foo.sys files will be converted into
foo_sys.ko (and foo_sys.o, for those who want/need to make static
kernels). This module contains all of the necessary info from the
.INF file and the driver binary image, converted into an ELF module.
You can kldload this module (or add it to /boot/loader.conf) to have
it loaded automatically. Any required firmware files can be bundled
into the module as well (or converted/loaded separately).

Also, add a workaround for a problem in NdisMSleep(). During system
bootstrap (cold == 1), msleep() always returns 0 without actually
sleeping. The Intel 2200BG driver uses NdisMSleep() to wait for
the NIC's firmware to come to life, and fails to load if NdisMSleep()
doesn't actually delay. As a workaround, if msleep() (and hence
ndis_thsuspend()) returns 0, use a hard DELAY() to sleep instead).
This is not really the right thing to do, but we can't really do much
else. At the very least, this makes the Intel driver happy.

There are probably other drivers that fail in this way during bootstrap.
Unfortunately, the only workaround for those is to avoid pre-loading
them and kldload them once the system is running instead.
2005-04-24 20:21:22 +00:00
wpaul
637643a433 Now that the GDT has been reorganized and GNDIS_SEL has been reserved
for us, use it if it's available, otherwise default to using slot 7
as before.
2005-04-17 19:36:08 +00:00
wpaul
f2f41f37b1 When setting up the new stack for a function in x86_64_wrap(), make
sure to make it 16-byte aligned, in keeping with amd64 calling
convention requirements.

Submitted by:	Mikore Li at sun dot com
2005-04-16 04:47:15 +00:00
jeff
afab3762a0 - Change all filesystems and vfs_cache to relock the dvp once the child is
locked in the ISDOTDOT case.  Se vfs_lookup.c r1.79 for details.

Sponsored by:	Isilon Systems, Inc.
2005-04-13 10:59:09 +00:00
mdodd
91ee5f450f Implement SOUND_MIXER_INFO ioctl in compat layer. 2005-04-13 04:33:06 +00:00
mdodd
6f940cf20f Add support for O_NOFOLLOW and O_DIRECT to Linux fcntl() F_GETFL/F_SETFL. 2005-04-13 04:31:43 +00:00
wpaul
a5aab37b5d In winx32_wrap.S, preserve return values in the fastcall and regparm
wrappers by pushing them onto the stack rather than keeping them in %esi
and %edi.
2005-04-11 17:04:49 +00:00
wpaul
a3b2d3191d Create new i386 windows/bsd thunking layer, similar to the amd64 thunking
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.
2005-04-11 02:02:35 +00:00