freebsd-skq/sys/compat/ndis/winx32_wrap.S
wpaul c104267c1a Tests with my dual Opteron system have shown that it's possible
for code to start out on one CPU when thunking into Windows
mode in ctxsw_utow(), and then be pre-empted and migrated to another
CPU before thunking back to UNIX mode in ctxsw_wtou(). This is
bad, because then we can end up looking at the wrong 'thread environment
block' when trying to come back to UNIX mode. To avoid this, we now
pin ourselves to the current CPU when thunking into Windows code.

Few other cleanups, since I'm here:

- Get rid of the ndis_isr(), ndis_enable_interrupt() and
  ndis_disable_interrupt() wrappers from kern_ndis.c and just invoke
  the miniport's methods directly in the interrupt handling routines
  in subr_ndis.c. We may as well lose the function call overhead,
  since we don't need to export these things outside of ndis.ko
  now anyway.

- Remove call to ndis_enable_interrupt() from ndis_init() in if_ndis.c.
  We don't need to do it there anyway (the miniport init routine handles
  it, if needed).

- Fix the logic in NdisWriteErrorLogEntry() a little.

- Change some NDIS_STATUS_xxx codes in subr_ntoskrnl.c into STATUS_xxx
  codes.

- Handle kthread_create() failure correctly in PsCreateSystemThread().
2005-11-02 18:01:04 +00:00

381 lines
12 KiB
ArmAsm

/*-
* Copyright (c) 2005
* Bill Paul <wpaul@windriver.com>. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asmacros.h>
/*
* This file contains assembly language wrappers for the different
* calling conventions supported by Windows on the i386 architecture.
* In FreeBSD, the whole OS typically use same C calling convention
* everywhere, namely _cdecl. Windows, on the other hand, uses several
* different C calling conventions depending on the circumstances:
*
* _stdcall: Used for most ordinary Windows APIs. With _stdcall,
* arguments are passed on the stack, and the callee unwinds the stack
* before returning control to the caller. Not suitable for variadic
* functions.
*
* _fastcall: Used for some APIs that may be invoked frequently and
* where speed is a critical factor (e.g. KeAcquireSpinLock() and
* KeReleaseSpinLock()) Similar to _stdcall, except the first 2 32-bit
* or smaller arguments are passed in the %ecx and %edx registers
* instead of on the stack. Not suitable for variadic functions.
*
* _cdecl: Used for standard C library routines and for variadic
* functions.
*
* _regparm(3): Used for certain assembly routines. All arguments
* passed in %eax, %ecx and %edx.
*
* Furthermore, there is an additional wrinkle that's not obvious
* with all code: Microsoft supports the use of exceptions in C
* (__try/__except) both in user _and_ kernel mode. Sadly, Windows
* structured exception handling uses machine-specific features
* that conflict rather badly with FreeBSD. (See utility routines
* at the end of this module for more details.)
*
* We want to support these calling conventions in as portable a manner
* as possible. The trick is doing it not only with different versions
* of GNU C, but with compilers other than GNU C (e.g. the Solaris
* SunOne C compiler). The only sure fire method is with assembly
* language trampoline code which both fixes up the argument passing,
* stack unwinding and exception/thread context all at once.
*
* You'll notice that we call the thunk/unthunk routines in the
* *_wrap() functions in an awkward way. Rather than branching
* directly to the address, we load the address into a register
* first as a literal value, then we branch to it. This is done
* to insure that the assembler doesn't translate the branch into
* a relative branch. We use the *_wrap() routines here as templates
* and create the actual trampolines at run time, at which point
* we only know the absolute addresses of the thunk and unthunk
* routines. So we need to make sure the templates have enough
* room in them for the full address.
*
* Also note that when we call the a thunk/unthunk routine after
* invoking a wrapped function, we have to make sure to preserve
* the value returned from that function. Most functions return
* a 32-bit value in %eax, however some routines return 64-bit
* values, which span both %eax and %edx. Consequently, we have
* to preserve both registers.
*/
/*
* Handle _stdcall going from Windows to UNIX.
* This is frustrating, because to do it right you have to
* know how many arguments the called function takes, and there's
* no way to figure this out on the fly: you just have to be told
* ahead of time. We assume there will be 16 arguments. I don't
* think there are any Windows APIs that require this many.
*/
.globl x86_stdcall_wrap_call
.globl x86_stdcall_wrap_arg
.globl x86_stdcall_wrap_end
ENTRY(x86_stdcall_wrap)
push %esi
push %edi
sub $64,%esp
mov %esp,%esi
add $64+8+4,%esi
mov %esp,%edi
mov $16,%ecx # handle up to 16 args
rep
movsl
movl $ctxsw_wtou, %eax
call *%eax # unthunk
x86_stdcall_wrap_call:
movl $0,%eax
call *%eax # jump to routine
push %eax # preserve return val
push %edx
movl $ctxsw_utow, %eax
call *%eax # thunk
pop %edx
pop %eax # restore return val
add $64,%esp # clean the stack
pop %edi
pop %esi
x86_stdcall_wrap_arg:
ret $0xFF
x86_stdcall_wrap_end:
/*
* Handle _stdcall going from UNIX to Windows. This routine
* expects to be passed the function to be called, number of
* args and the arguments for the Windows function on the stack.
*/
ENTRY(x86_stdcall_call)
push %esi # must preserve %esi
push %edi # and %edi
mov 16(%esp),%eax # get arg cnt
mov %eax,%ecx # save as copy count
mov %esp,%esi # Set source address register to point to
add $20,%esi # first agument to be forwarded.
shl $2,%eax # turn arg cnt into offset
sub %eax,%esp # shift stack to new location
mov %esp,%edi # store dest copy addr
rep # do the copy
movsl
call ctxsw_utow # thunk
call *12(%edi) # branch to stdcall routine
push %eax # preserve return val
push %edx
call ctxsw_wtou # unthunk
pop %edx
pop %eax # restore return val
mov %edi,%esp # restore stack
pop %edi # restore %edi
pop %esi # and %esi
ret
/*
* Fastcall support. Similar to _stdcall, except the first
* two arguments are passed in %ecx and %edx. It happens we
* only support a small number of _fastcall APIs, none of them
* take more than three arguments. So to keep the code size
* and complexity down, we only handle 3 arguments here.
*/
/* Call _fastcall function going from Windows to UNIX. */
.globl x86_fastcall_wrap_call
.globl x86_fastcall_wrap_arg
.globl x86_fastcall_wrap_end
ENTRY(x86_fastcall_wrap)
mov 4(%esp),%eax
push %eax
push %edx
push %ecx
movl $ctxsw_wtou, %eax
call *%eax # unthunk
x86_fastcall_wrap_call:
mov $0,%eax
call *%eax # branch to fastcall routine
push %eax # preserve return val
push %edx
movl $ctxsw_utow, %eax
call *%eax # thunk
pop %edx
pop %eax # restore return val
add $12,%esp # clean the stack
x86_fastcall_wrap_arg:
ret $0xFF
x86_fastcall_wrap_end:
/*
* Call _fastcall function going from UNIX to Windows.
* This routine isn't normally used since NDIS miniport drivers
* only have _stdcall entry points, but it's provided anyway
* to round out the API, and for testing purposes.
*/
ENTRY(x86_fastcall_call)
mov 4(%esp),%eax
push 16(%esp)
call ctxsw_utow # thunk
mov 12(%esp),%ecx
mov 16(%esp),%edx
call *8(%esp) # branch to fastcall routine
push %eax # preserve return val
push %edx
call ctxsw_wtou # unthunk
pop %edx
pop %eax # restore return val
add $4,%esp # clean the stack
ret
/*
* Call regparm(3) function going from Windows to UNIX. Arguments
* are passed in %eax, %edx and %ecx. Note that while additional
* arguments are passed on the stack, we never bother when them,
* since the only regparm(3) routines we need to wrap never take
* more than 3 arguments.
*/
.globl x86_regparm_wrap_call
.globl x86_regparm_wrap_end
ENTRY(x86_regparm_wrap)
push %ecx
push %edx
push %eax
movl $ctxsw_wtou, %eax
call *%eax # unthunk
x86_regparm_wrap_call:
movl $0,%eax
call *%eax # jump to routine
push %eax # preserve return val
push %edx # preserve return val
movl $ctxsw_utow, %eax
call *%eax # thunk
pop %edx # restore return val
pop %eax # restore return val
add $12,%esp # restore stack
ret
x86_regparm_wrap_end:
/*
* Call regparm(3) function going from UNIX to Windows.
* This routine isn't normally used since NDIS miniport drivers
* only have _stdcall entry points, but it's provided anyway
* to round out the API, and for testing purposes.
*/
ENTRY(x86_regparm_call)
call ctxsw_utow # thunk
mov 8(%esp),%eax
mov 12(%esp),%edx
mov 16(%esp),%ecx
call *4(%esp) # branch to fastcall routine
push %eax # preserve return val
push %edx # preserve return val
call ctxsw_wtou # unthunk
pop %edx # restore return val
pop %eax # restore return val
ret
/*
* Ugly hack alert:
*
* On Win32/i386, using __try/__except results in code that tries to
* manipulate what's supposed to be the Windows Threada Environment
* Block (TEB), which one accesses via the %fs register. In particular,
* %fs:0 (the first DWORD in the TEB) points to the exception
* registration list. Unfortunately, FreeBSD uses %fs for the
* per-cpu data structure (pcpu), and we can't allow Windows code
* to muck with that. I don't even know what Solaris uses %fs for
* (or if it even uses it at all).
*
* Even worse, in 32-bit protected mode, %fs is a selector that
* refers to an entry in either the GDT or the LDT. Ideally, we would
* like to be able to temporarily point it at another descriptor
* while Windows code executes, but to do that we need a separate
* descriptor entry of our own to play with.
*
* Therefore, we go to some trouble to learn the existing layout of
* the GDT and update it to include an extra entry that we can use.
* We need the following utility routines to help us do that. On
* FreeBSD, index #7 in the GDT happens to be unused, so we turn
* this into our own data segment descriptor. It would be better
* if we could use a private LDT entry, but there's no easy way to
* do that in SMP mode because of the way FreeBSD handles user LDTs.
*
* Once we have a custom descriptor, we have to thunk/unthunk whenever
* we cross between FreeBSD code and Windows code. The thunking is
* based on the premise that when executing instructions in the
* Windows binary itself, we won't go to sleep. This is because in
* order to yield the CPU, the code has to call back out to a FreeBSD
* routine first, and when that happens we can unthunk in order to
* restore FreeBSD context. What we're desperately trying to avoid is
* being involuntarily pre-empted with the %fs register still pointing
* to our fake TIB: if FreeBSD code runs with %fs pointing at our
* Windows TIB instead of pcpu, we'll panic the kernel. Fortunately,
* the only way involuntary preemption can occur is if an interrupt
* fires, and the trap handler saves/restores %fs for us.
*
* The thunking routines themselves, ctxsw_utow() (Context SWitch UNIX
* to Windows) and ctxsw_wtou() (Context SWitch Windows to UNIX), are
* external to this module. This is done simply because it's easier
* to manipulate data structures in C rather than assembly.
*/
ENTRY(x86_getldt)
movl 4(%esp),%eax
sgdtl (%eax)
movl 8(%esp),%eax
sldt (%eax)
xor %eax,%eax
ret
ENTRY(x86_setldt)
movl 4(%esp),%eax
lgdt (%eax)
jmp 1f
nop
1:
movl 8(%esp),%eax
lldt %ax
xor %eax,%eax
ret
ENTRY(x86_getfs)
mov %fs,%ax
ret
ENTRY(x86_setfs)
movl 4(%esp),%fs
ret
ENTRY(x86_gettid)
mov %fs:12,%eax
ret
ENTRY(x86_critical_enter)
cli
ret
ENTRY(x86_critical_exit)
sti
ret