[llvm] [llvm-objdump][ELF]Fix crash when reading strings from .dynstr (PR #125679)

[James Henderson via llvm-commits]

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@@ -221,6 +221,28 @@ template <class ELFT> void ELFDumper<ELFT>::printDynamicSection() {
   std::string TagFmt = "  %-" + std::to_string(MaxLen) + "s ";
 
   outs() << "\nDynamic Section:\n";
+  typename ELFT::Xword StringTableSize{0};
+  for (const typename ELFT::Shdr &Sec : cantFail(Elf.sections())) {
+    if (Sec.sh_type == ELF::SHT_DYNSYM) {
+      Expected<const typename ELFT::Shdr *> StringTableSecOrError =
+          getSection<ELFT>(cantFail(Elf.sections()), Sec.sh_link);
+      if (!StringTableSecOrError) {
+        consumeError(StringTableSecOrError.takeError());
+        break;
+      }
+      StringTableSize = StringTableSize < (*StringTableSecOrError)->sh_size
+                            ? (*StringTableSecOrError)->sh_size
+                            : StringTableSize;
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jh7370 wrote:

The ternary isn't necessary. The dynamic section will only reference one string table, so you'll only have one size by this point.

In fact, once you find the dynamic section and have read the string size from it, you can bail out of the loop.

https://github.com/llvm/llvm-project/pull/125679