Hi Jeshua,

On 10/10/23 17:41, Jeshua Smith wrote:
#3 is not currently used by any published code. It is a development aid, which 
the ObjectParser itself seems to be.

Here's why I added it. Several people on our team have (not yet upstreamed) changes that 
resulted in additional ObjectIDs being added to the ObjectID enums, but without 
corresponding parsers being added to the ObjectParser. Dumping of the objects with the 
ObjectParser wasn't enabled by default, so this wasn't detected by them. Without #1 the 
ObjectParser code does out of bounds array accesses, sometimes leading to crashes. #1 
will now detect and report that problem. When I enabled dumping of objects to debug my 
new code, I hit this bug leading me to write #1. For me to work around the issue of 
missing parsers in order to be able to continue debug with my work, the "easy" 
solution was for me to temporarily add the new ObjectIDs to the parser list with NULL 
parsers and then inform the responsible parties that they need to go and add parsers for 
their new ObjectIDs. Doing this required #3 (support for NULL parsers) to be added. 
Ideally any code that is upstreamed back to EDKII will have non-NULL parsers at the point 
it is sent upstream, but allowing in-development changes to temporarily use NULL parsers 
is helpful.

Hopefully that clarifies things.

Thanks for the detailed explanation,
Reviewed-by: Pierre Gondois <pierre.gond...@arm.com>


-----Original Message-----
From: Pierre Gondois <pierre.gond...@arm.com>
Sent: Tuesday, October 10, 2023 4:14 AM
To: Jeshua Smith <jesh...@nvidia.com>; devel@edk2.groups.io
Cc: sami.muja...@arm.com
Subject: Re: [PATCH 2/2] DynamicTablesPkg/TableHelperLib: Enhance error handling

External email: Use caution opening links or attachments


Hello Jeshua,

On 10/6/23 18:28, Jeshua Smith wrote:
This patch enhances error handling and reporting in the CM ObjectParser.
Specifically:
1. ObjectIDs used as array indexes are checked for being out of bounds,
     and if so an error message is printed before the assert.
2. An error message is printed for unsupported NameSpaceIDs.
3. Adds support for unimplemented parsers by allowing IDs to list a
     NULL parser, resulting in an unimplemented message being printed.

I am not sure I see in which context 3. would be used/necessary. Is it possible 
to detail ?

(Code-wise everything looks good to me)

Regards,
Pierre



Signed-off-by: Jeshua Smith <jesh...@nvidia.com>
---
   .../ConfigurationManagerObjectParser.c        | 47 +++++++++++++------
   1 file changed, 33 insertions(+), 14 deletions(-)

diff --git
a/DynamicTablesPkg/Library/Common/TableHelperLib/ConfigurationManagerO
bjectParser.c
b/DynamicTablesPkg/Library/Common/TableHelperLib/ConfigurationManagerO
bjectParser.c
index 92df1efee8..22b8fdb906 100644
---
a/DynamicTablesPkg/Library/Common/TableHelperLib/ConfigurationManagerO
bjectParser.c
+++ b/DynamicTablesPkg/Library/Common/TableHelperLib/ConfigurationMana
+++ gerObjectParser.c
@@ -795,6 +795,7 @@ STATIC CONST CM_OBJ_PARSER_ARRAY  
StdNamespaceObjectParser[] = {
       ARRAY_SIZE (StdObjAcpiTableInfoParser) },
     { "EStdObjSmbiosTableList", StdObjSmbiosTableInfoParser,
       ARRAY_SIZE (StdObjSmbiosTableInfoParser) },
+  { "EStdObjMax",             NULL,                       0}
   };

   /** Print string data.
@@ -1066,6 +1067,12 @@ ParseCmObjDesc (
           return;
         }

+      if (ObjId >= ARRAY_SIZE (StdNamespaceObjectParser)) {
+        DEBUG ((DEBUG_ERROR, "ObjId 0x%x is missing from the 
StdNamespaceObjectParser array\n", ObjId));
+        ASSERT (0);
+        return;
+      }
+
         ParserArray = &StdNamespaceObjectParser[ObjId];
         break;
       case EObjNameSpaceArm:
@@ -1074,10 +1081,17 @@ ParseCmObjDesc (
           return;
         }

+      if (ObjId >= ARRAY_SIZE (ArmNamespaceObjectParser)) {
+        DEBUG ((DEBUG_ERROR, "ObjId 0x%x is missing from the 
ArmNamespaceObjectParser array\n", ObjId));
+        ASSERT (0);
+        return;
+      }
+
         ParserArray = &ArmNamespaceObjectParser[ObjId];
         break;
       default:
         // Not supported
+      DEBUG ((DEBUG_ERROR, "NameSpaceId 0x%x, ObjId 0x%x is not
+ supported by the parser\n", NameSpaceId, ObjId));
         ASSERT (0);
         return;
     } // switch
@@ -1095,21 +1109,26 @@ ParseCmObjDesc (
         ObjIndex + 1,
         ObjectCount
         ));
-    PrintCmObjDesc (
-      (VOID *)((UINTN)CmObjDesc->Data + Offset),
-      ParserArray->Parser,
-      ParserArray->ItemCount,
-      &RemainingSize,
-      1
-      );
-    if ((RemainingSize > CmObjDesc->Size) ||
-        (RemainingSize < 0))
-    {
-      ASSERT (0);
-      return;
-    }
+    if (ParserArray->Parser == NULL) {
+      DEBUG ((DEBUG_ERROR, "Parser not implemented\n"));
+      RemainingSize = 0;
+    } else {
+      PrintCmObjDesc (
+        (VOID *)((UINTN)CmObjDesc->Data + Offset),
+        ParserArray->Parser,
+        ParserArray->ItemCount,
+        &RemainingSize,
+        1
+        );
+      if ((RemainingSize > CmObjDesc->Size) ||
+          (RemainingSize < 0))
+      {
+        ASSERT (0);
+        return;
+      }

-    Offset = CmObjDesc->Size - RemainingSize;
+      Offset = CmObjDesc->Size - RemainingSize;
+    }
     } // for

     ASSERT (RemainingSize == 0);


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#109524): https://edk2.groups.io/g/devel/message/109524
Mute This Topic: https://groups.io/mt/101801385/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-


Reply via email to