ShellPkg/Acpiview: Refactor EINJ table parser validation

ACPI defines Injection Header Size as the length of the EINJ
injection header, not necessarily the absolute offset of the
instruction entries. Update parser validation to use the correct
entry offset calculation and accept the layout used by Linux and
existing firmware tables.

Signed-off-by: Simon Wang <simowang@nvidia.com>

ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Einj/EinjParser.c

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Einj/EinjParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Einj/EinjParser.c
index d01b15f..5e5dc08 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Einj/EinjParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Einj/EinjParser.c
@@ -327,7 +327,9 @@
              );

 

   // Validate Error Source Descriptors Count.

-  if ((mEinjInjectionHdrSize == NULL) || (*mEinjInjectionHdrSize != Offset)) {

+  if ((mEinjInjectionHdrSize == NULL) ||

+      (*mEinjInjectionHdrSize != (Offset - sizeof (EFI_ACPI_DESCRIPTION_HEADER))))

+  {

     IncrementErrorCount ();

     Print (L"ERROR: Invalid Injection Header...\n");

     return;