[llvm-readelf/llvm-readobj] - Check version of SHT_GNU_verdef section entries when dumping.

Elfxx_Verdef contains the following field:

vd_version
Version revision. This field shall be set to 1.
(https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/symversion.html)

Our code should check the struct version for correctness. This patch does that.
(This will help to simplify or eliminate ELFDumper<ELFT>::LoadVersionDefs() which
has it's own logic to parse version definitions for no reason. It checks the
struct version currently).

Differential revision: https://reviews.llvm.org/D70810

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 79d08d379a1..51ea599f4be 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -409,6 +409,12 @@ ELFDumper<ELFT>::getVersionDefinitions(const Elf_Shdr *Sec) const {
           ": found a misaligned version definition entry at offset 0x" +
           Twine::utohexstr(VerdefBuf - Start));
 
+    unsigned Version = *reinterpret_cast<const Elf_Half *>(VerdefBuf);
+    if (Version != 1)
+      return createError("unable to dump SHT_GNU_verdef section with index " +
+                         Twine(SecNdx) + ": version " + Twine(Version) +
+                         " is not yet supported");
+
     const Elf_Verdef *D = reinterpret_cast<const Elf_Verdef *>(VerdefBuf);
     VerDef &VD = *Ret.emplace(Ret.end());
     VD.Offset = VerdefBuf - Start;