This is a temporary helper for the system call entry point to store the user mode stack, before switching to the kernel mode stack. Initially it was copied to the trap frame inside KiSystemCallHandler. This has been moved to the system call entry point, but some remnants remained. The problem is that KiSystemCallHandler can be called twice in a system call (when the call is the first GUI call and the stack needs to be extended). In that scenario, when the thread was preempted, a new value could be saved in the PCR before running KiSystemCallHandler again, and then overwriting the proper value with a bogus one from a different thread. This rarely seemed to happen on UP, but happens a lot with SMP.
Pass a proper write/execute flag in the ExceptionInformation[0] field of the exception record instead of the raw fault code. This fixes comdlg:filedlg wine test, which writes to a write protected resource section, which needs to be handled by kernel32 UnhandledExceptionFilter, which relies on this parameter to be correct.
- Implement KiExceptionExit, which works like KiServiceExit2, but takes an exception frame as 2nd parameter
- Add a local exception frame to NtRaiseException and NtContinue, which is needed to exit with a full context on x64 and arm
- Use KeContextToTrapFrame again instead of KiSetTrapContext, since we have a proper exception frame now.
The registers that are saved/restored in the trap / exception frame need to be consistent between all entry/exit points as well as the functions that convert between trap/exception frame and context. The trap frame contains only the non-volatile registers and rbp, the rest is saved in the exception frame.
The previous code didn't save rbp in the syscall handler, which led to it being clobbered when exiting though KiServiceExit2 rather than returning back to the syscall exit path. Also KeContextToTrapFrame would use rbx, rsi and rdi from the trap frame, which wouldn't be saved there by the syscall handler.
We need to save the missing registers in the trap frame before calling KiInitiateUserApc, because they will be used to create the CONTEXT that is saved on the user mode stack, where KiUserApcDispatcher returns back to using NtContinue. This fixes remaining failures in kernel32_apitest QueueUserAPC.
This is used in KiUserModeCallout instead of KiServiceExit2. The latter is broken, leaks non-volatile registers and will need to be modified to handle an exception frame, which we don't need/have here. It will also use sysret instead of iret and is generally simpler/faster.
Eventually it would be desirable to skip the entire trap frame setup and do everything in KiCallUserMode. This requires some cleanup and special handling for user APC delivery.
This also fixes delivering APCs from the system call handler, which previously would have clobbered rax. Also don't use the thread's TrapFrame member, which is not always set, when returning.
This is needed, because KiSystemCallHandler can be called multiple times for the same syscall entry, which would mess up the linkage. This replaces a previous hack and makes things cleaner.
- Use an index for the table instead of ugly pointer offset
- Invert the check for GUI calls
- Fail with proper status code on invalid win32k syscall ids
This is required since while interrupts are enabled, another user APC could get queued and we want to guarantee that those are all delivered before returning to user mode.
CORE-1697
Raise IRQL to SYNCH_LEVEL when exiting from the idle thread in the
idle loop, in case it is scheduled for execution. Then restore it
back to DISPATCH_LEVEL, after this is done.
This behaviour is a bit similar to the way it's done on x64.
This IRQL raise is necessary only in SMP builds.
Calls are placed in CONFIG_SMP ifdef: this avoids unnecessary IRQL
changes on UP, since SYNCH_LEVEL and DISPATCH_LEVEL are identical
there, unlike in MP, where SYNCH_LEVEL is IPI_LEVEL - 2 actually.
This prevents bugcheck DRIVER_IRQL_NOT_LESS_OR_EQUAL when booting
SMP x86 ReactOS, in KiTimerExpiration when calling it 2nd time.
The BSOD happened due to IRQL levels mismatch.
Co-authored-by: Victor Perevertkin <victor.perevertkin@reactos.org>
Introduce the initial changes needed to get other processors up and into kernel mode.
This only supports x86 as of now but is the first real step towards using other system processors.
The function set CtxSwitchFrame->ApcBypass to FALSE, preventing APCs (like when user mode sets the context while the thread is suspended) from being delivered as soon as the thread lowers IRQL to PASSIVE_LEVEL. This resulted in the SetContext APC to be delivered only after the user mode APC was initialized, overwriting the user mode APC context in the trap frame. This caused kernel32_winetest process to break.
This should be performed early enough before CM initialization,
but after the TSC has been initialized and calibrated by HAL.
Based on existing i386 kiinit code. CORE-17971 CORE-14922
