Changeset 12855 in vbox for trunk/src/VBox/VMM/PATM

Timestamp:

Oct 1, 2008 9:37:46 AM (17 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

37231

Message:

Mark referenced patches, so they can't be removed.

Location:

trunk/src/VBox/VMM/PATM

Files:

• PATM.cpp (modified) (10 diffs)
• PATMInternal.h (modified) (1 diff)
• VMMGC/PATMGC.cpp (modified) (2 diffs)

trunk/src/VBox/VMM/PATM/PATM.cpp

@@ -1048 +1048 @@
             /* Special case: call function replacement patch from this patch block.
              */
-            if (PATMQueryFunctionPatch(pVM, pRec->pTargetGC) == 0)
+            PPATMPATCHREC pFunctionRec = PATMQueryFunctionPatch(pVM, pRec->pTargetGC);
+            if (!pFunctionRec)
             {
                 int rc;
@@ -1080 +1081 @@
                 }
             }
+            else
+            {
+                Log(("Patch block %VRv called as function\n", pFunctionRec->patch.pPrivInstrGC));
+                pFunctionRec->patch.flags |= PATMFL_CODE_REFERENCED;
+            }
+
             pBranchTargetGC = PATMR3QueryPatchGCPtr(pVM, pRec->pTargetGC);
         }
@@ -4079 +4086 @@
                 }
             }
-            PATMR3RemovePatch(pVM, pInstrGC);
+            rc = PATMR3RemovePatch(pVM, pInstrGC);
+            if (VBOX_FAILURE(rc))
+                return VERR_PATCHING_REFUSED;
         }
         else
@@ -4727 +4736 @@
                             Log(("PATMR3PatchWrite: overwriting jump to patch code -> remove patch.\n"));
                             int rc = PATMR3RemovePatch(pVM, pPatch->pPrivInstrGC);
-                            AssertRC(rc);
-
-                            /** @note jump back to the start as the pPatchPage has been deleted or changed */
-                            goto loop_start;
+                            if (rc == VINF_SUCCESS)
+                                /** @note jump back to the start as the pPatchPage has been deleted or changed */
+                                goto loop_start;
+
+                            continue;
                         }
 
@@ -5232 +5242 @@
                         STAM_COUNTER_INC(&pVM->patm.s.StatOverwritten);
                         /* Remove it completely */
-                        PATMR3RemovePatch(pVM, pInstrGC);
+                        rc = PATMR3RemovePatch(pVM, pInstrGC);
+                        AssertRC(rc);
                         return VERR_PATCH_NOT_FOUND;
                     }
@@ -5269 +5280 @@
                     Log(("PATMR3EnablePatch: Can't enable a patch who's guest code has changed!!\n"));
                     STAM_COUNTER_INC(&pVM->patm.s.StatOverwritten);
-                    PATMR3RemovePatch(pVM, pInstrGC);
+                    rc = PATMR3RemovePatch(pVM, pInstrGC);
+                    AssertRC(rc);
                     return VERR_PATCH_NOT_FOUND;
                 }
@@ -5311 +5323 @@
 
     /* Strictly forbidden to remove such patches. There can be dependencies!! */
-    AssertReturn(fForceRemove || !(pPatch->flags & (PATMFL_DUPLICATE_FUNCTION)), VERR_ACCESS_DENIED);
+    if (!fForceRemove && (pPatch->flags & (PATMFL_DUPLICATE_FUNCTION|PATMFL_CODE_REFERENCED)))
+    {
+        Log(("PATMRemovePatch %VRv REFUSED!\n", pPatch->pPrivInstrGC));
+        return VERR_ACCESS_DENIED;
+    }
+    Log(("PATMRemovePatch %VRv\n", pPatch->pPrivInstrGC));
 
     /** @note NEVER EVER REUSE PATCH MEMORY */
@@ -5464 +5481 @@
         LogRel(("PATM: patmR3RefreshPatch: succeeded to refresh patch at %VRv \n", pInstrGC));
         STAM_COUNTER_INC(&pVM->patm.s.StatPatchRefreshSuccess);
+
+        /* Used by another patch, so don't remove it! */
+        pNewPatchRec->patch.flags |= PATMFL_CODE_REFERENCED;
     }
 
@@ -5985 +6005 @@
         pPatch = PATM_PATCHREC_FROM_COREOFFSET(pvPatchCoreOffset);
 
+        Assert(offset >= pPatch->patch.pPatchBlockOffset && offset < pPatch->patch.pPatchBlockOffset + pPatch->patch.cbPatchBlockSize);
+
         if (pPatch->patch.uState == PATCH_DIRTY)
         {
             Log(("PATMR3HandleTrap: trap in dirty patch at %VRv\n", pEip));
-            if (pPatch->patch.flags & (PATMFL_DUPLICATE_FUNCTION|PATMFL_CALLABLE_AS_FUNCTION))
+            if (pPatch->patch.flags & (PATMFL_DUPLICATE_FUNCTION|PATMFL_CODE_REFERENCED))
             {
                 /* Function duplication patches set fPIF to 1 on entry */
@@ -5998 +6020 @@
         {
             Log(("PATMR3HandleTrap: trap in disabled patch at %VRv\n", pEip));
-            if (pPatch->patch.flags & (PATMFL_DUPLICATE_FUNCTION|PATMFL_CALLABLE_AS_FUNCTION))
+            if (pPatch->patch.flags & (PATMFL_DUPLICATE_FUNCTION|PATMFL_CODE_REFERENCED))
             {
                 /* Function duplication patches set fPIF to 1 on entry */

trunk/src/VBox/VMM/PATM/PATMInternal.h

@@ -79 +79 @@
 #define PATMFL_INT3_REPLACEMENT_BLOCK       RT_BIT_64(32) /** int 3 replacement block */
 #define PATMFL_EXTERNAL_JUMP_INSIDE         RT_BIT_64(33) /** A trampoline patch was created that jumps to an instruction in the patch block */
+#define PATMFL_CODE_REFERENCED              RT_BIT_64(34) /** patch block referenced (called, jumped to) by another patch. */
 
 #define SIZEOF_NEARJUMP8                   2 //opcode byte + 1 byte relative offset

trunk/src/VBox/VMM/PATM/VMMGC/PATMGC.cpp

@@ -201 +201 @@
                         if (rc == VINF_SUCCESS)
                         {
+                            Log(("Patch block %VRv called as function\n", pRec->patch.pPrivInstrGC));
+                            pRec->patch.flags |= PATMFL_CODE_REFERENCED;
+
                             pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE;
                             pRegFrame->eax = pRelAddr;
@@ -218 +221 @@
                 else
                 {
-#if 0
-                    if (pRegFrame->edx == 0x806eca98) 
-                    {
-                        pRegFrame->eip += PATM_ILLEGAL_INSTR_SIZE;
-                        pRegFrame->eax = 0;     /* make it fault */
-                        STAM_COUNTER_INC(&pVM->patm.s.StatFunctionNotFound);
-                        return VINF_SUCCESS;
-                    } 
-#endif
                     STAM_COUNTER_INC(&pVM->patm.s.StatFunctionNotFound);
                     return VINF_PATM_DUPLICATE_FUNCTION;