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[NTOSKRNL]

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Fix NtQueryTimerResolution and NtSetTimerResolution to work in kernel mode.


svn path=/branches/ntvdm/; revision=59305
This commit is contained in:
Aleksandar Andrejevic 2013-06-23 08:44:46 +00:00
parent 4ffafc388d
commit 7befc34a4f
1 changed files with 45 additions and 20 deletions
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65
ntoskrnl/ke/clock.c
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@ -242,23 +242,37 @@ NtQueryTimerResolution(OUT PULONG MinimumResolution,
OUT PULONG MaximumResolution,
OUT PULONG ActualResolution)
{
_SEH2_TRY
{
/* Probe the parameters */
ProbeForWriteUlong(MinimumResolution);
ProbeForWriteUlong(MaximumResolution);
ProbeForWriteUlong(ActualResolution);
KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
/* Set the parameters to the actual values */
/* Check if the call came from user mode */
if (PreviousMode != KernelMode)
{
_SEH2_TRY
{
/* Probe the parameters */
ProbeForWriteUlong(MinimumResolution);
ProbeForWriteUlong(MaximumResolution);
ProbeForWriteUlong(ActualResolution);
/* Try to set the parameters to the actual values */
*MinimumResolution = KeMinimumIncrement;
*MaximumResolution = KeMaximumIncrement;
*ActualResolution = KeTimeIncrement;
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
/* Return the exception code */
_SEH2_YIELD(return _SEH2_GetExceptionCode());
}
_SEH2_END;
}
else
{
/* The call came from kernel mode. Use the pointers directly */
*MinimumResolution = KeMinimumIncrement;
*MaximumResolution = KeMaximumIncrement;
*ActualResolution = KeTimeIncrement;
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
_SEH2_YIELD(return _SEH2_GetExceptionCode());
}
_SEH2_END;
/* Return success */
return STATUS_SUCCESS;
@ -271,21 +285,32 @@ NtSetTimerResolution(IN ULONG DesiredResolution,
OUT PULONG CurrentResolution)
{
ULONG NewResolution;
KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
/* Call the internal API */
NewResolution = ExSetTimerResolution(DesiredResolution, SetResolution);
/* Return the resolution to the caller */
_SEH2_TRY
/* Check if the call came from user mode */
if (PreviousMode != KernelMode)
{
ProbeForWriteUlong(CurrentResolution);
/* Try to write the value */
_SEH2_TRY
{
ProbeForWriteUlong(CurrentResolution);
*CurrentResolution = NewResolution;
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
/* Return the exception code */
_SEH2_YIELD(return _SEH2_GetExceptionCode());
}
_SEH2_END;
}
else
{
/* The call came from kernel mode. Use the pointer directly */
*CurrentResolution = NewResolution;
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
_SEH2_YIELD(return _SEH2_GetExceptionCode());
}
_SEH2_END;
/* Return success if we set the resolution */
if (SetResolution) return STATUS_SUCCESS;