[FAST486]

Don't perform privilege checks while reading the IDT, GDT or TSS.

svn path=/trunk/; revision=67648

diff --git a/reactos/lib/fast486/common.c b/reactos/lib/fast486/common.c
index 36c69d4..6e499af 100644 (file)
--- a/reactos/lib/fast486/common.c
+++ b/reactos/lib/fast486/common.c
@@ -123,7 +123,7 @@ Fast486ReadMemory(PFAST486_STATE State,
             {
                 /* We can't prefetch without possibly violating page permissions */
                 State->PrefetchValid = FALSE;
-                return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size);
+                return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size, TRUE);
             }
         }
 
@@ -131,7 +131,8 @@ Fast486ReadMemory(PFAST486_STATE State,
         if (Fast486ReadLinearMemory(State,
                                     State->PrefetchAddress,
                                     State->PrefetchCache,
-                                    FAST486_CACHE_SIZE))
+                                    FAST486_CACHE_SIZE,
+                                    TRUE))
         {
             State->PrefetchValid = TRUE;
 
@@ -150,7 +151,7 @@ Fast486ReadMemory(PFAST486_STATE State,
 #endif
     {
         /* Read from the linear address */
-        return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size);
+        return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size, TRUE);
     }
 }
 
@@ -236,7 +237,7 @@ Fast486WriteMemory(PFAST486_STATE State,
 #endif
 
     /* Write to the linear address */
-    return Fast486WriteLinearMemory(State, LinearAddress, Buffer, Size);
+    return Fast486WriteLinearMemory(State, LinearAddress, Buffer, Size, TRUE);
 }
 
 static inline BOOLEAN
@@ -253,7 +254,8 @@ Fast486GetIntVector(PFAST486_STATE State,
                                      State->Idtr.Address
                                      + Number * sizeof(*IdtEntry),
                                      IdtEntry,
-                                     sizeof(*IdtEntry)))
+                                     sizeof(*IdtEntry),
+                                     FALSE))
         {
             /* Exception occurred */
             return FALSE;
@@ -325,7 +327,8 @@ Fast486InterruptInternal(PFAST486_STATE State,
                                          State->TaskReg.Base,
                                          &Tss,
                                          State->TaskReg.Limit >= sizeof(FAST486_TSS)
-                                         ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS)))
+                                         ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS),
+                                         FALSE))
             {
                 /* Exception occurred */
                 return FALSE;
@@ -622,7 +625,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
                                  State->TaskReg.Base,
                                  &OldTss,
                                  State->TaskReg.Limit >= sizeof(FAST486_TSS)
-                                 ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS)))
+                                 ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS),
+                                 FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -649,7 +653,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
     if (!Fast486ReadLinearMemory(State,
                                  State->Gdtr.Address + GET_SEGMENT_INDEX(Selector),
                                  &NewTssDescriptor,
-                                 sizeof(NewTssDescriptor)))
+                                 sizeof(NewTssDescriptor),
+                                 FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -703,7 +708,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
                                  NewTssAddress,
                                  &NewTss,
                                  NewTssLimit >= sizeof(FAST486_TSS)
-                                 ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS)))
+                                 ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS),
+                                 FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -718,7 +724,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
                                      State->Gdtr.Address
                                      + GET_SEGMENT_INDEX(State->TaskReg.Selector),
                                      &OldTssDescriptor,
-                                     sizeof(OldTssDescriptor)))
+                                     sizeof(OldTssDescriptor),
+                                     FALSE))
         {
             /* Exception occurred */
             return FALSE;
@@ -730,7 +737,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
                                       State->Gdtr.Address
                                       + GET_SEGMENT_INDEX(State->TaskReg.Selector),
                                       &OldTssDescriptor,
-                                      sizeof(OldTssDescriptor)))
+                                      sizeof(OldTssDescriptor),
+                                      FALSE))
         {
             /* Exception occurred */
             return FALSE;
@@ -789,7 +797,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
                                   State->TaskReg.Base,
                                   &OldTss,
                                   State->TaskReg.Limit >= sizeof(FAST486_TSS)
-                                  ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS)))
+                                  ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS),
+                                  FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -802,7 +811,8 @@ Fast486TaskSwitch(PFAST486_STATE State, FAST486_TASK_SWITCH_TYPE Type, USHORT Se
     if (!Fast486WriteLinearMemory(State,
                                   State->Gdtr.Address + GET_SEGMENT_INDEX(Selector),
                                   &NewTssDescriptor,
-                                  sizeof(NewTssDescriptor)))
+                                  sizeof(NewTssDescriptor),
+                                  FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -1041,7 +1051,8 @@ Fast486CallGate(PFAST486_STATE State,
                                          State->TaskReg.Base,
                                          &Tss,
                                          State->TaskReg.Limit >= sizeof(FAST486_TSS)
-                                         ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS)))
+                                         ? sizeof(FAST486_TSS) : sizeof(FAST486_LEGACY_TSS),
+                                         FALSE))
             {
                 /* Exception occurred */
                 return FALSE;

diff --git a/reactos/lib/fast486/common.inl b/reactos/lib/fast486/common.inl
index fed1386..3fd2a4e 100644 (file)
--- a/reactos/lib/fast486/common.inl
+++ b/reactos/lib/fast486/common.inl
@@ -150,7 +150,8 @@ FASTCALL
 Fast486ReadLinearMemory(PFAST486_STATE State,
                         ULONG LinearAddress,
                         PVOID Buffer,
-                        ULONG Size)
+                        ULONG Size,
+                        BOOLEAN CheckPrivilege)
 {
     /* Check if paging is enabled */
     if (State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_PG)
@@ -177,7 +178,7 @@ Fast486ReadLinearMemory(PFAST486_STATE State,
                 PageLength -= PageOffset;
             }
 
-            if (!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
+            if (CheckPrivilege && (!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0))))
             {
                 State->ControlRegisters[FAST486_REG_CR2] = Page + PageOffset;
 
@@ -219,7 +220,8 @@ FASTCALL
 Fast486WriteLinearMemory(PFAST486_STATE State,
                          ULONG LinearAddress,
                          PVOID Buffer,
-                         ULONG Size)
+                         ULONG Size,
+                         BOOLEAN CheckPrivilege)
 {
     /* Check if paging is enabled */
     if (State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_PG)
@@ -246,9 +248,10 @@ Fast486WriteLinearMemory(PFAST486_STATE State,
                 PageLength -= PageOffset;
             }
 
-            if ((!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
+            if (CheckPrivilege
+                && ((!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
                 || ((State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_WP)
-                && !TableEntry.Writeable))
+                && !TableEntry.Writeable)))
             {
                 State->ControlRegisters[FAST486_REG_CR2] = Page + PageOffset;
 
@@ -503,7 +506,8 @@ Fast486ReadDescriptorEntry(PFAST486_STATE State,
                                      State->Gdtr.Address
                                      + GET_SEGMENT_INDEX(Selector),
                                      Entry,
-                                     sizeof(*Entry)))
+                                     sizeof(*Entry),
+                                     FALSE))
         {
             /* Exception occurred */
             *EntryValid = FALSE;
@@ -524,7 +528,8 @@ Fast486ReadDescriptorEntry(PFAST486_STATE State,
                                      State->Ldtr.Base
                                      + GET_SEGMENT_INDEX(Selector),
                                      Entry,
-                                     sizeof(*Entry)))
+                                     sizeof(*Entry),
+                                     FALSE))
         {
             /* Exception occurred */
             *EntryValid = FALSE;

diff --git a/reactos/lib/fast486/opgroups.c b/reactos/lib/fast486/opgroups.c
index a611273..f540904 100644 (file)
--- a/reactos/lib/fast486/opgroups.c
+++ b/reactos/lib/fast486/opgroups.c
@@ -1979,7 +1979,8 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeGroup0F00)
                 Fast486WriteLinearMemory(State,
                                          State->Gdtr.Address + GET_SEGMENT_INDEX(Selector),
                                          &GdtEntry,
-                                         sizeof(GdtEntry));
+                                         sizeof(GdtEntry),
+                                         FALSE /* We already made sure CPL is 0 */);
             }
 
             break;