[PATCH] D67078: [llvm-readelf] - Allow dumping the dynamic symbols when there is no program headers.

Mon Sep 2 09:26:05 PDT 2019

MaskRay added inline comments.

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Comment at: test/tools/llvm-readobj/dyn-symbols.test:185
+      - Tag:   DT_SYMTAB
+        Value: 0
+      - Tag:   DT_NULL
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The test is different from https://reviews.llvm.org/D62179#1652778

In https://reviews.llvm.org/D62179#1652778, there is no program headers (corrupted phdr), so toMappedAddr returns a nullptr. Here, DT_SYMTAB is 0. When the information from DT_SYMTAB and .dynsym conflict, we probably should let DT_DYNTAB win...

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Comment at: tools/llvm-readobj/ELFDumper.cpp:1656
+      if (!DynSymRegion.EntSize) {
+        DynSymRegion.Addr = toMappedAddr(Dyn.getTag(), Dyn.getPtr());
+        DynSymRegion.EntSize = sizeof(Elf_Sym);
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We probably should check whether `toMappedAddr` returns a nullptr - which is the case if there is no program headers. This approach may be better than

  if (!DynSymRegion.EntSize) {

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  https://reviews.llvm.org/D67078/new/

https://reviews.llvm.org/D67078