[COFF] Don't reject executables with data directories pointing outside of provided data

Before bb94611d6545c2c5271f5bb01de1aa4228a37250, we didn't check
that the sections in the COFF executable actually contained enough
raw data, when looking up what section contains tables pointed to
by the data directories.

That commit added checking, to avoid setting a pointer that points
out of bounds - by rejecting such executables.

It turns out that some binaries (e.g.g a "helper.exe" provided by
NSIS) contains a base relocation table data directory that points
into the wrong section. It points inside the virtual address space
allocated for that section, but the section contains much less raw
data, and the table points outside of the provided raw data.

No longer reject such binaries (to let tools operate on them and
inspect them), but don't set the table pointers (so that when
printing e.g. base relocations, we don't print anything).

This should fix the regression pointed out in
https://reviews.llvm.org/D126898#3565834.

Differential Revision: https://reviews.llvm.org/D127345

1 files changed, 4 insertions, 10 deletions

diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index e5013d77..ee5411d 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -483,18 +483,12 @@ Error COFFObjectFile::getRvaPtr(uint32_t Addr, uintptr_t &Res,
       // fail, otherwise it will be impossible to use this object as debug info
       // in LLDB. Return SectionStrippedError here so that
       // COFFObjectFile::initialize can ignore the error.
-      if (Section->SizeOfRawData == 0)
-        return make_error<SectionStrippedError>();
+      // Somewhat common binaries may have RVAs pointing outside of the
+      // provided raw data. Instead of rejecting the binaries, just
+      // treat the section as stripped for these purposes.
       if (Section->SizeOfRawData < Section->VirtualSize &&
           Addr >= SectionStart + Section->SizeOfRawData) {
-        if (ErrorContext)
-          return createStringError(object_error::parse_failed,
-                                   "RVA 0x%" PRIx32
-                                   " for %s found but data is incomplete",
-                                   Addr, ErrorContext);
-        return createStringError(
-            object_error::parse_failed,
-            "RVA 0x%" PRIx32 " found but data is incomplete", Addr);
+        return make_error<SectionStrippedError>();
       }
       uint32_t Offset = Addr - SectionStart;
       Res = reinterpret_cast<uintptr_t>(base()) + Section->PointerToRawData +