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[FAST486]

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Implement privilege checks when loading the code selector.


svn path=/branches/ntvdm/; revision=61056
This commit is contained in:
Aleksandar Andrejevic 2013-11-20 10:43:12 +00:00
parent b456a8b355
commit e2fb91925e
1 changed files with 59 additions and 10 deletions
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69
lib/fast486/common.inl
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@ -430,36 +430,85 @@ Fast486LoadSegment(PFAST486_STATE State,
if (!GdtEntry.SystemType)
{
/* This is a special descriptor */
Fast486Exception(State, FAST486_EXCEPTION_GP);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
if (GdtEntry.Executable || !GdtEntry.ReadWrite)
{
Fast486Exception(State, FAST486_EXCEPTION_GP);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
if ((GET_SEGMENT_RPL(Selector) != Fast486GetCurrentPrivLevel(State))
|| (GET_SEGMENT_RPL(Selector) != GdtEntry.Dpl))
{
Fast486Exception(State, FAST486_EXCEPTION_GP);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
if (!GdtEntry.Present)
{
Fast486Exception(State, FAST486_EXCEPTION_SS);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_SS, Selector);
return FALSE;
}
}
else if (Segment == FAST486_REG_CS)
{
/* Loading the code segment */
// TODO: Implement security checks, call gates, etc...
/* Update CPL */
State->Cpl = GET_SEGMENT_RPL(Selector);
if (GET_SEGMENT_INDEX(Selector) == 0)
{
Fast486Exception(State, FAST486_EXCEPTION_GP);
return FALSE;
}
if (GdtEntry.SystemType)
{
// TODO: Call/interrupt/task gates NOT IMPLEMENTED!
UNIMPLEMENTED;
}
else
{
if (!GdtEntry.Present)
{
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_NP, Selector);
return FALSE;
}
if (!GdtEntry.Executable)
{
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
if (GdtEntry.DirConf)
{
/* Conforming Code Segment */
if (GdtEntry.Dpl > Fast486GetCurrentPrivLevel(State))
{
/* Must be accessed from lower-privileged code */
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
}
else
{
/* Regular code segment */
if ((GET_SEGMENT_RPL(Selector) > Fast486GetCurrentPrivLevel(State))
|| (Fast486GetCurrentPrivLevel(State) != GdtEntry.Dpl))
{
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
}
/* Update CPL */
State->Cpl = GET_SEGMENT_RPL(Selector);
}
}
else
{
@ -468,20 +517,20 @@ Fast486LoadSegment(PFAST486_STATE State,
if (!GdtEntry.SystemType)
{
/* This is a special descriptor */
Fast486Exception(State, FAST486_EXCEPTION_GP);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
if ((GET_SEGMENT_RPL(Selector) > GdtEntry.Dpl)
|| (Fast486GetCurrentPrivLevel(State) > GdtEntry.Dpl))
{
Fast486Exception(State, FAST486_EXCEPTION_GP);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_GP, Selector);
return FALSE;
}
if (!GdtEntry.Present)
{
Fast486Exception(State, FAST486_EXCEPTION_NP);
Fast486ExceptionWithErrorCode(State, FAST486_EXCEPTION_NP, Selector);
return FALSE;
}
}