Changeset 97861 in vbox for trunk/src/VBox/Runtime/common/compiler/vcc

Timestamp:

Dec 23, 2022 4:55:55 PM (2 years ago)

Author:

vboxsync

Message:

IPRT/nocrt: Fixes to C_specific_handler. bugref:10261 ticketref:21303

File:

• trunk/src/VBox/Runtime/common/compiler/vcc/except-seh-vcc.cpp (modified) (7 diffs)

trunk/src/VBox/Runtime/common/compiler/vcc/except-seh-vcc.cpp

@@ -48 +48 @@
 #endif
 
+
+/**
+ * Calls an exception filter w/o doing any control guard checks.
+ *
+ * Doing this within an inline function to prevent disabling CFG for any other
+ * calls that __C_specific_handler might be doing.
+ *
+ * Presumably, the presumption here is that since the target address here is
+ * taken from tables assumed to be readonly and generated by the compiler, there
+ * is no need to do any CFG checks.  Besides, the target isn't a function that
+ * is safe to be called out of context and thus doesn't belong in the CFG tables
+ * in any way.
+ */
+__declspec(guard(ignore))
+DECLINLINE(LONG) CallFilterFunction(PEXCEPTION_FILTER pfnFilter, PEXCEPTION_POINTERS pXcptPtrs,
+                                    PEXCEPTION_REGISTRATION_RECORD pXcptRegRec)
+{
+    return pfnFilter(pXcptPtrs, pXcptRegRec);
+}
+
+
+/**
+ * Calls an exception finally block w/o doing any control guard checks.
+ *
+ * See CallFilterFunction for details.
+ */
+__declspec(guard(ignore))
+DECLINLINE(void) CallFinallyFunction(PTERMINATION_HANDLER const pfnTermHandler, BOOLEAN fAbend,
+                                     PEXCEPTION_REGISTRATION_RECORD pXcptRegRec)
+{
+    pfnTermHandler(fAbend, pXcptRegRec);
+}
 
 
@@ -112 +144 @@
                         PEXCEPTION_FILTER  const pfnFilter = (PEXCEPTION_FILTER)(pDispCtx->ImageBase + uFltTermHandler);
                         EXCEPTION_POINTERS       XcptPtrs  = { pXcptRec, pCpuCtx };
-                        /** @todo shouldn't we do a guard check on this call? */
-                        lRet = pfnFilter(&XcptPtrs, pXcptRegRec);
+                        lRet = CallFilterFunction(pfnFilter, &XcptPtrs, pXcptRegRec);
 
                         AssertCompile(EXCEPTION_CONTINUE_SEARCH == 0);
@@ -120 +151 @@
                     }
 
-                    /* Return if we're supposed to continue execution (the convension
+                    /* Return if we're supposed to continue execution (the convention
                        it to match negative values rather than the exact defined value):  */
                     AssertCompile(EXCEPTION_CONTINUE_EXECUTION == -1);
@@ -152 +183 @@
                                  ? pDispCtx->TargetIp - pDispCtx->ImageBase
                                  : UINT32_MAX;
+        //RTAssertMsg2("__C_specific_handler: unwind: idxScope=%#x cScopes=%#x uTargetPc=%#x fXcpt=%#x\n", idxScope, cScopes, uTargetPc, pXcptRec->ExceptionFlags);
 
         for (; idxScope < cScopes; idxScope++)
@@ -177 +209 @@
                             uint32_t const uTgtEnd    = pScopeTab->ScopeRecord[idxTgtScope].EndAddress;
                             uint32_t const cbTgtScope = uTgtEnd - uTgtBegin;
-                            if (   uTargetPc - uTgtBegin < uTgtBegin
+                            if (   uTargetPc - uTgtBegin < cbTgtScope
                                 && uTgtBegin < uTgtEnd /* paranoia */)
+                            {
+                                //RTAssertMsg2("__C_specific_handler: ExceptionContinueSearch (#1)\n");
                                 return ExceptionContinueSearch;
+                            }
                         }
                 }
@@ -188 +223 @@
                     PTERMINATION_HANDLER const pfnTermHandler = (PTERMINATION_HANDLER)(pDispCtx->ImageBase + uFltTermHandler);
                     pDispCtx->ScopeIndex = idxScope + 1;
-                    /** @todo shouldn't we do a guard check on this call? */
-                    pfnTermHandler(TRUE /*fAbend*/, pXcptRegRec);
+                    //RTAssertMsg2("__C_specific_handler: Calling __finally %p (idxScope=%#x)\n", pfnTermHandler, idxScope);
+                    CallFinallyFunction(pfnTermHandler, TRUE /*fAbend*/, pXcptRegRec);
                 }
                 /* Exception filter & handler entries are skipped, unless the exception
@@ -196 +231 @@
                 else if (   uXcptHandler == uTargetPc
                          && (pXcptRec->ExceptionFlags & EXCEPTION_TARGET_UNWIND))
+                {
+                    //RTAssertMsg2("__C_specific_handler: ExceptionContinueSearch (#2)\n");
                     return ExceptionContinueSearch;
+                }
             }
         }