[ros-diffs] [aandrejevic] 67648: [FAST486] Don't perform privilege checks while reading the IDT, GDT or TSS.

Author: aandrejevic
Date: Mon May 11 02:49:25 2015
New Revision: 67648

URL: http://svn.reactos.org/svn/reactos?rev=67648&view=rev
Log:
[FAST486]
Don't perform privilege checks while reading the IDT, GDT or TSS.


Modified:
    trunk/reactos/lib/fast486/common.c
    trunk/reactos/lib/fast486/common.inl
    trunk/reactos/lib/fast486/opgroups.c

Modified: trunk/reactos/lib/fast486/common.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/fast486/common.c?rev=6…
==============================================================================
--- trunk/reactos/lib/fast486/common.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/fast486/common.c	[iso-8859-1] Mon May 11 02:49:25 2015
@@ -123,7 +123,7 @@
             {
                 /* 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 @@
         if (Fast486ReadLinearMemory(State,
                                     State->PrefetchAddress,
                                     State->PrefetchCache,
-                                    FAST486_CACHE_SIZE))
+                                    FAST486_CACHE_SIZE,
+                                    TRUE))
         {
             State->PrefetchValid = TRUE;
 
@@ -150,7 +151,7 @@
 #endif
     {
         /* Read from the linear address */
-        return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size);
+        return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size, TRUE);
     }
 }
 
@@ -236,7 +237,7 @@
 #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 @@
                                      State->Idtr.Address
                                      + Number * sizeof(*IdtEntry),
                                      IdtEntry,
-                                     sizeof(*IdtEntry)))
+                                     sizeof(*IdtEntry),
+                                     FALSE))
         {
             /* Exception occurred */
             return FALSE;
@@ -325,7 +327,8 @@
                                          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 @@
                                  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 @@
     if (!Fast486ReadLinearMemory(State,
                                  State->Gdtr.Address + GET_SEGMENT_INDEX(Selector),
                                  &NewTssDescriptor,
-                                 sizeof(NewTssDescriptor)))
+                                 sizeof(NewTssDescriptor),
+                                 FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -703,7 +708,8 @@
                                  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 @@
                                      State->Gdtr.Address
                                      + GET_SEGMENT_INDEX(State->TaskReg.Selector),
                                      &OldTssDescriptor,
-                                     sizeof(OldTssDescriptor)))
+                                     sizeof(OldTssDescriptor),
+                                     FALSE))
         {
             /* Exception occurred */
             return FALSE;
@@ -730,7 +737,8 @@
                                       State->Gdtr.Address
                                       + GET_SEGMENT_INDEX(State->TaskReg.Selector),
                                       &OldTssDescriptor,
-                                      sizeof(OldTssDescriptor)))
+                                      sizeof(OldTssDescriptor),
+                                      FALSE))
         {
             /* Exception occurred */
             return FALSE;
@@ -789,7 +797,8 @@
                                   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 @@
     if (!Fast486WriteLinearMemory(State,
                                   State->Gdtr.Address + GET_SEGMENT_INDEX(Selector),
                                   &NewTssDescriptor,
-                                  sizeof(NewTssDescriptor)))
+                                  sizeof(NewTssDescriptor),
+                                  FALSE))
     {
         /* Exception occurred */
         return FALSE;
@@ -1041,7 +1051,8 @@
                                          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;

Modified: trunk/reactos/lib/fast486/common.inl
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/fast486/common.inl?rev…
==============================================================================
--- trunk/reactos/lib/fast486/common.inl	[iso-8859-1] (original)
+++ trunk/reactos/lib/fast486/common.inl	[iso-8859-1] Mon May 11 02:49:25 2015
@@ -150,7 +150,8 @@
 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 @@
                 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 @@
 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 @@
                 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 @@
                                      State->Gdtr.Address
                                      + GET_SEGMENT_INDEX(Selector),
                                      Entry,
-                                     sizeof(*Entry)))
+                                     sizeof(*Entry),
+                                     FALSE))
         {
             /* Exception occurred */
             *EntryValid = FALSE;
@@ -524,7 +528,8 @@
                                      State->Ldtr.Base
                                      + GET_SEGMENT_INDEX(Selector),
                                      Entry,
-                                     sizeof(*Entry)))
+                                     sizeof(*Entry),
+                                     FALSE))
         {
             /* Exception occurred */
             *EntryValid = FALSE;

Modified: trunk/reactos/lib/fast486/opgroups.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/fast486/opgroups.c?rev…
==============================================================================
--- trunk/reactos/lib/fast486/opgroups.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/fast486/opgroups.c	[iso-8859-1] Mon May 11 02:49:25 2015
@@ -1979,7 +1979,8 @@
                 Fast486WriteLinearMemory(State,
                                          State->Gdtr.Address +
GET_SEGMENT_INDEX(Selector),
                                          &GdtEntry,
-                                         sizeof(GdtEntry));
+                                         sizeof(GdtEntry),
+                                         FALSE /* We already made sure CPL is 0 */);
             }
 
             break;