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Optimize NtGetContextThread a bit and fix use of unitinialized memory if PreviousMode == KernelMode and Thread ==

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CurrentThread (thanks to Thomas for spotting!)

svn path=/trunk/; revision=18967
This commit is contained in:
Gregor Anich 2005-11-03 00:34:09 +00:00
parent 662797cc94
commit 55db859f00
1 changed files with 12 additions and 3 deletions
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15
reactos/ntoskrnl/ps/debug.c
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@ -86,6 +86,7 @@ NtGetContextThread(IN HANDLE ThreadHandle,
KPROCESSOR_MODE PreviousMode = ExGetPreviousMode(); KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
GET_SET_CTX_CONTEXT GetSetContext; GET_SET_CTX_CONTEXT GetSetContext;
NTSTATUS Status = STATUS_SUCCESS; NTSTATUS Status = STATUS_SUCCESS;
PCONTEXT SafeThreadContext = NULL;
PAGED_CODE(); PAGED_CODE();
@ -98,6 +99,7 @@ NtGetContextThread(IN HANDLE ThreadHandle,
sizeof(CONTEXT), sizeof(CONTEXT),
sizeof(ULONG)); sizeof(ULONG));
GetSetContext.Context = *ThreadContext; GetSetContext.Context = *ThreadContext;
SafeThreadContext = &GetSetContext.Context;
} _SEH_HANDLE { } _SEH_HANDLE {
@ -106,6 +108,8 @@ NtGetContextThread(IN HANDLE ThreadHandle,
} _SEH_END; } _SEH_END;
if(!NT_SUCCESS(Status)) return Status; if(!NT_SUCCESS(Status)) return Status;
} else {
SafeThreadContext = ThreadContext;
} }
/* Get the Thread Object */ /* Get the Thread Object */
@ -121,15 +125,20 @@ NtGetContextThread(IN HANDLE ThreadHandle,
/* Check if we're running in the same thread */ /* Check if we're running in the same thread */
if(Thread == PsGetCurrentThread()) { if(Thread == PsGetCurrentThread()) {
/* /*
* I don't know if trying to get your own context makes much * I don't know if trying to get your own context makes much
* sense but we can handle it more efficently. * sense but we can handle it more efficently.
*/ */
KeTrapFrameToContext(Thread->Tcb.TrapFrame, NULL, &GetSetContext.Context); KeTrapFrameToContext(Thread->Tcb.TrapFrame, NULL, SafeThreadContext);
} else { } else {
/* Copy context into GetSetContext if not already done */
if(PreviousMode == KernelMode) {
GetSetContext.Context = *ThreadContext;
SafeThreadContext = &GetSetContext.Context;
}
/* Use an APC... Initialize the Event */ /* Use an APC... Initialize the Event */
KeInitializeEvent(&GetSetContext.Event, KeInitializeEvent(&GetSetContext.Event,
NotificationEvent, NotificationEvent,
@ -173,7 +182,7 @@ NtGetContextThread(IN HANDLE ThreadHandle,
ObDereferenceObject(Thread); ObDereferenceObject(Thread);
/* Check for success and return the Context */ /* Check for success and return the Context */
if(NT_SUCCESS(Status)) { if(NT_SUCCESS(Status) && SafeThreadContext != ThreadContext) {
_SEH_TRY { _SEH_TRY {
*ThreadContext = GetSetContext.Context; *ThreadContext = GetSetContext.Context;