[PATCH] D28502: [compiler-rt] [Interception] Properly check for export table's size before referring to its elements.

[Marcos Pividori via Phabricator via llvm-commits]

mpividori created this revision.
mpividori added reviewers: zturner, rnk.
mpividori added a subscriber: llvm-commits.
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Herald added a subscriber: dberris.

This fix a bug, when calling `InternalGetProcAddress()` for an executable that doesn't export any symbol. So the table is empty.
If we don't check for this condition, the program fails with Error 0xc0000142.


Repository:
  rL LLVM

https://reviews.llvm.org/D28502

Files:
  lib/interception/interception_win.cc


Index: lib/interception/interception_win.cc
===================================================================
--- lib/interception/interception_win.cc
+++ lib/interception/interception_win.cc
@@ -878,6 +878,8 @@
 
   IMAGE_DATA_DIRECTORY *export_directory =
       &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
+  if (!(export_directory->Size))
+    return 0;
   RVAPtr<IMAGE_EXPORT_DIRECTORY> exports(module,
                                          export_directory->VirtualAddress);
   RVAPtr<DWORD> functions(module, exports->AddressOfFunctions);


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