UefiTestingPkg: Fix memory info database dump

[makubacki]

Description

Fixes: #924

Memory info is stored in mMemoryInfoDatabaseBuffer. The code first calculates how large of a buffer is needed. A "dry run" is performed to compute that. It calls each dump handler with AllowAllocation=FALSE, to get the size of the data that would be written.

However, the call to LoadedImageTableDump() during this phase, sets AllowAllocation=TRUE. mMemoryInfoDatabaseOffset is still NULL, then AppendMemoryInfoDatabase() sees that and allocates a buffer.

Now, mMemoryInfoDatabaseSize is advanced. Other dump handlers after write to the buffer now that it exists.

Eventually, DumpPagingInfo() allocates the real (intended) buffer. Because of what happened earlier, the "accidental" buffer is leaked and mMemoryInfoDatabaseSize is non-zero which causes mMemoryInfoDatabaseBuffer[mMemoryInfoDatabaseSize] to write past the beginning of the buffer:

  // Copy the new string to the end of the buffer and update the size.
  if (!EFI_ERROR (Status)) {
    CopyMem (&mMemoryInfoDatabaseBuffer[mMemoryInfoDatabaseSize], DatabaseString, NewStringSize);
    mMemoryInfoDatabaseSize = NewDatabaseSize;
  }

This change sets AllowAllocation=FALSE in that call and resets mMemoryInfoDatabaseSize to zero before the real allocation as a precaution.

• Impacts functionality?
• Impacts security?
• Breaking change?
• Includes tests?
• Includes documentation?

How This Was Tested

1. Before - Reproduce the problem:

   

   (venv) paging>python PagingReportGenerator.py -i ..\collection_data -o report1.html
   Traceback (most recent call last):
     File "paging\PagingReportGenerator.py", line 312, in <module>
       retcode = main()
     File "paging\PagingReportGenerator.py", line 294, in main
       spt.Parse()
       ~~~~~~~~~^^
     File "paging\PagingReportGenerator.py", line 79, in Parse
       self.MemoryRangeInfo.extend(ParseInfoFile(info))
                                   ~~~~~~~~~~~~~^^^^^^
     File "paging\BinaryParsing.py", line 38, in ParseInfoFile
       MemoryRanges.append(MemoryRange(row[0], *row[1:]))
                           ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
     File "paging\MemoryRangeObjects.py", line 126, in __init__
       raise RuntimeError("Unknown type '%s' found!" % self.RecordType)
   RuntimeError: Unknown type 'MemoryMap' found!
   

2. After - Verify the problem no longer exists:

   

   python Windows\PagingReportGenerator.py -i ../collection_data -o report1.html
   

Integration Instructions

• N/A

[mu-automation]

✅ QEMU Validation Passed

Source Dependencies

Repository	Commit
mu_plus	d76d97e
mu_tiano_platforms	d8ecfb8

Results

Platform	Target	Build	Boot	Overall Boot Time	Build Logs	Boot Logs
Q35	DEBUG	✅ success	✅ success	0m 19s	Build Logs	Boot Logs
ArmVirt	DEBUG	✅ success	✅ success	0m 14s	Build Logs	Boot Logs

Workflow run: https://github.com/microsoft/mu_plus/actions/runs/30105774308

This comment was automatically generated by the Mu QEMU PR Validation workflow.