This commit fully implements the inner logic of KeSaveFloatingPointState and KeRestoreFloatingPointState routines. On ReactOS we're currently simply doing a FNSAVE operation whereas on Windows it is a lot more than that.
On Windows Server 2003 the logic more or less goes like this. In order to save the FPU state the NPX state of the current thread has to be checked first, that is, if NPX is loaded and currently charged for the current thread then the system will acquire the NPX registers actively present. From that point it performs either a FNSAVE or FXSAVE
if FX is actually supported. Otherwise the control word and MXCsr registers are obtained.
FXSAVE/FNSAVE operation is done solely if the FX save area is held up in a pool allocation. Pool allocation occurs if it's been found out that the NPX IRQL of the thread is not the same as the current thread which from where it determines if the interrupt level is APC then allocate some pool memory and hold the save area there, otherwise
the save area in question is grabbed from the current processor control region. If NPX is not loaded for the current thread then the FPU state is obtained from the NPX frame.
In our case we'll be doing something way simpler. Only do a FXSAVE/FNSAVE directly of the FPU state registers, in this way we are simplifying the code and the actual logic of Save/Restore mechanism.
Currently, these features are vital for the kernel:
- CPUID instruction
- CMPXCHG8B instruction
- TSC aka Time Stamp Counter
All of that have to be present on i586
Also generate processor identifier properly based on this value
on the Configuration Manager machine-dependent initialization.
Update processor driver INF file accordingly.
CORE-17970 CORE-14922
We have a special file, tag.h, which serves as a place to store whatever kernel pool allocation tag yet we still have some tags sparse over the kernel code... So just re-group them in one unique place.
Addendum to 608032bd and 835c3023.
The IRQL is actually raised by KeFreezeExecution() and lowered by
KeThawExecution(), always to HIGH_IRQL on MP systems, or if necessary
on UP. These functions are called respectively by KdEnterDebugger()
and KdExitDebugger().
KiSetTrapContext is an asm wrapper around RtlSetUnwindContext, which first stores an exception frame to assure that all non-volatile registers were put on the stack, then calls RtlSetUnwindContext to update their first saving positions on the stack and finally restore the exception frame to potentially load any updated registers, that haven't been saved elsewhere on the stack.
- Change INIT_FUNCTION and INIT_SECTION to CODE_SEG("INIT") and DATA_SEG("INIT") respectively
- Remove INIT_FUNCTION from function prototypes
- Remove alloc_text pragma calls as they are not needed anymore
- Deliver pending APCs on trap exit
- Pass the trapframe of KiApcInterrupt to KiDeliverApcs, not NULL.
- Fix parameter passing from KiSwapContext to KiSwapContextInternal and KiSwapContextResume, so that the ApcBypass parameter is not uninitialized
- Fix return value of KiSwapContextResume to correctly indicate whether we want to have APCs directly delivered or not (when there are non, or when delivery is suppressed)
The previous version (like the x86 one) used a combination of C and asm code, called from C code to switch the stack. This is problematic, since there is no guarantee what assumptions C code makes about the stack (i.e. it can place any kind of stack pointers into registers or on the stack itself.) The new algorithm returns back to the systemcall entry point in asm, which then calls KiConvertToGuiThread, which is also asm and calls KeSwitchKernelStack ...
To be 100% correct and not rely on assumptions, stack switching can only be done when all previous code - starting with the syscall entry point - is pure asm code, since we can't rely on the C compiler to not use stack addresses in a way that is not transparent. Therefore the new code uses the same mechanism as for normal system calls, returning the address of the asm function KiConvertToGuiThread, which is then called like an Nt* function would be called normally. KiConvertToGuiThread then allocated a new stack, switches to it (which is now fine, since all the code is asm), frees the old stack, calls PsConvertToGuiThread (which now will not try to allocate another stack, since we already have one) and then jumps into the middle of KiSystemCallEntry64, where the system call is handled again.
Also simplify KiSystemCallEntry64 a bit by copying the first parameters into the trap frame, avoiding to allocate additional stack space for the call to KiSystemCallHandler, which now overlaps with the space that is allocated for the Nt* function.
Finally fix the locations where r10 and r11 are stored, which is TrapFrame->Rcx and TrapFrame->EFlags, based on the situation in user mode.
- Add boot video color constants
- Refactor palette initialization
- Move some common stuff in right place
- Get rid of some magic constants and hardcoded values
- Get rid of TopDelta variable (calculated at compile time)
- Update SAL annotations
Addendum to 5f2ca473. CORE-16216 CORE-16219
The trap frame is in a random location on the stack, and setting Esp0 there
wastes significant amounts of space and may lead to unexpected stack overflows.
Also use a more descriptive expression for the V86 members of the KTRAP_FRAME.
Our legacy KD module is slowly being phased out for the more recent KD64
Kernel Debugger that supports WinDbg, but at the same time we must retain
support for GCC debugging and the KDBG interface.
For the time being few #ifdef _WINKD_ have been introduced in KD64 so that
some of its code/data does not completely get shared yet with the legacy KD,
until the latter becomes phased out.
KD Modifications:
=================
- Remove the implementation of NtQueryDebugFilterState() /
NtSetDebugFilterState() that now comes entirely from KD64.
- Remove KD variables that are now shared with KD64.
- Share common code with KD64: KdpMoveMemory(), KdpZeroMemory(),
KdpCopyMemoryChunks(), KdpPrint(), KdpPrompt().
- KDBG: Remove the duplicated KdpCopyMemoryChunks() function.
- In KdpServiceDispatcher() and KdpEnterDebuggerException(), call the
KdpPrint() worker function that correctly probes and captures its arguments.
- Temporarily stub out KdEnterDebugger() and KdExitDebugger() that is used
by the shared code, until KD is removed and only the KD64 version of these
functions remain.
- Re-implement the KD/KDBG KdpPrompt() function using a custom KdpPromptString()
helper compatible with KD64, that is called by the KD64 implementation of
KdpPrompt(). This KdpPromptString() helper now issues the prompt on all
the KD loggers: e.g. if you use both at the same time COM-port and SCREEN
debugging, the prompt will appear on both. Before that the prompt was always
being displayed on COM port even if e.g. a SCREEN-only debug session was used...
- ppc_irq.c: Fix the prototype of KdpServiceDispatcher().
KD64 Fixes:
===========
- Initialize the MaximumLength member of the counted STRING variables
before using them elsewhere.
- Get rid of alloca() within SEH block in KdpPrint() (addendum to 7b95fcf9).
- Add the ROS-specific handy dump commands in KdSystemDebugControl().
- Introduce the MmMakeKernelResourceSectionWritable() helper for
making the kernel resource memory section writable, and use it
in KeGetBugMessageText(). Indeed, this latter function patches
in place the bugcheck resource message to trim any trailing
newlines before displaying the message on screen.
See also https://github.com/osresearch/uxen/blob/83bad53/dm/introspection-win7.c#L286
that mentions it too.
This fixes bugcheck text display (e.g. the MANUALLY_INITIATED_CRASH one)
when using (at least) MSVC-built ReactOS, avoiding a Page-Fault
exception during the bugcheck.
- Cover KeGetBugMessageText() in SEH since we are accessing kernel
resources that could also be corrupted in bugcheck scenarii, and we
don't want to further bugcheck.
- Fix newline trimming loop.
- KiDoBugCheckCallbacks():
* Wrap the bugcheck CallbackRoutine call in SEH.
* Add a FIXME concerning the need of further memory validation of CurrentRecord.
- Add a FIXME concerning the need to run the bugcheck-reason callbacks
with the KbCallbackReserved1 reason, in KeBugCheckWithTf().
Mentioned in http://blog.ptsecurity.com/2012/06/customizing-blue-screen-of-death.html
