MdeModulePkg/Core/Dxe: assert SectionInstance invariant in FindChildNode()

[mirror_edk2.git] / MdeModulePkg / Core / Dxe / SectionExtraction / CoreSectionExtraction.c

diff --git a/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c b/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
index d678166db475423d56154c6d1c57b23a8cafc17e..d7f7ef427422cb7044fc775dac4eec5bd7341e1a 100644 (file)
--- a/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
+++ b/MdeModulePkg/Core/Dxe/SectionExtraction/CoreSectionExtraction.c
@@ -952,8 +952,8 @@ CreateChildNode (
                                  search.\r
   @param  SearchType             Indicates the type of section to search for.\r
   @param  SectionInstance        Indicates which instance of section to find.\r
-                                 This is an in/out parameter to deal with\r
-                                 recursions.\r
+                                 This is an in/out parameter and it is 1-based,\r
+                                 to deal with recursions.\r
   @param  SectionDefinitionGuid  Guid of section definition\r
   @param  FoundChild             Output indicating the child node that is found.\r
   @param  FoundStream            Output indicating which section stream the child\r
@@ -988,6 +988,8 @@ FindChildNode (
   EFI_STATUS                                    ErrorStatus;\r
   EFI_STATUS                                    Status;\r
 \r
+  ASSERT (*SectionInstance > 0);\r
+\r
   CurrentChildNode = NULL;\r
   ErrorStatus = EFI_NOT_FOUND;\r
 \r
@@ -1037,6 +1039,11 @@ FindChildNode (
       }\r
     }\r
 \r
+    //\r
+    // Type mismatch, or we haven't found the desired instance yet.\r
+    //\r
+    ASSERT (*SectionInstance > 0);\r
+\r
     if (CurrentChildNode->EncapsulatedStreamHandle != NULL_STREAM_HANDLE) {\r
       //\r
       // If the current node is an encapsulating node, recurse into it...\r
@@ -1050,16 +1057,20 @@ FindChildNode (
                 &RecursedFoundStream,\r
                 AuthenticationStatus\r
                 );\r
-      //\r
-      // If the status is not EFI_SUCCESS, just save the error code and continue\r
-      // to find the request child node in the rest stream.\r
-      //\r
       if (*SectionInstance == 0) {\r
+        //\r
+        // The recursive FindChildNode() call decreased (*SectionInstance) to\r
+        // zero.\r
+        //\r
         ASSERT_EFI_ERROR (Status);\r
         *FoundChild = RecursedChildNode;\r
         *FoundStream = RecursedFoundStream;\r
         return EFI_SUCCESS;\r
       } else {\r
+        //\r
+        // If the status is not EFI_SUCCESS, just save the error code and\r
+        // continue to find the request child node in the rest stream.\r
+        //\r
         ErrorStatus = Status;\r
       }\r
     } else if ((CurrentChildNode->Type == EFI_SECTION_GUID_DEFINED) && (SearchType != EFI_SECTION_GUID_DEFINED)) {\r