[obj2yaml] - Dump the content of a broken hash table properly.

[grimar]

Summary

This is similar to D93760.

When something is wrong with the hash table header we dump
its context as a raw data.

Currently we have the calculation overflow issue and it is possible to
bypass the validation we have (and crash).

The patch fixes it.

llvm/test/tools/obj2yaml/ELF/hash-section.yaml

 # CONTENT-NEXT:   Type:    SHT_HASH
 # CONTENT-NEXT:   Content: '00'
 # CONTENT-NEXT: - Name:    .truncated
 # CONTENT-NEXT:   Type:    SHT_HASH
 # CONTENT-NEXT:   Content: '01000000020000000300000004000000'
 # CONTENT-NEXT: - Name:    .oversized
 # CONTENT-NEXT:   Type:    SHT_HASH
 # CONTENT-NEXT:   Content: '0100000002000000030000000400000000'
+# CONTENT-NEXT: - Name:    .overflow1
+# CONTENT-NEXT:   Type:    SHT_HASH
+# CONTENT-NEXT:   Content: 01000000FFFFFFFF{{$}}
+# CONTENT-NEXT: - Name:    .overflow2
+# CONTENT-NEXT:   Type:    SHT_HASH
+# CONTENT-NEXT:   Content: FFFFFFFF01000000{{$}}
+# CONTENT-NEXT: ...
 
 --- !ELF
 FileHeader:
   Class: ELFCLASS32
   Data:  ELFDATA2LSB
   Type:  ET_DYN
 Sections:
 ## Case 1: section has no data.
##         Section size is less than (2 * nbucket + nchain) * 4.
   - Name:    .truncated
     Type:    SHT_HASH
     Content: '01000000020000000300000004000000'
 ## Case 4: nbucket == 1, nchain == 2.
 ##         Section size is greater than (2 * nbucket + nchain) * 4.
   - Name:    .oversized
     Type:    SHT_HASH
     Content: '0100000002000000030000000400000000'
+## Case 5, 6: NChain/NBucket are incorrect and causing 32-bit
+##            unsigned overflows of intermediate expressions.
+  - Name:    .overflow1
+    Type:    SHT_HASH
+    Bucket:  [ ]
+    Chain:   [ ]
+    NBucket: 0x1
+    NChain:  0xffffffff
+  - Name:    .overflow2
+    Type:    SHT_HASH
+    Bucket:  [ ]
+    Chain:   [ ]
+    NBucket: 0xffffffff
+    NChain:  0x1
 
 ## Check how we dump the "EntSize" field. When the sh_entsize is 4,
 ## we don't print it, because it is the default value for the SHT_HASH section.
 
 # RUN: yaml2obj --docnum=3 %s -o %t3
 # RUN: obj2yaml %t3 | FileCheck %s --check-prefix=ENT-SIZE
 
 # ENT-SIZE:      - Name:    .hash.entsize.0

llvm/tools/obj2yaml/elf2yaml.cpp

ELFDumper<ELFT>::dumpHashSection(const Elf_Shdr *Shdr) {
   ArrayRef<uint8_t> Content = *ContentOrErr;
   if (Content.size() % 4 != 0 || Content.size() < 8) {
     S->Content = yaml::BinaryRef(Content);
     return S.release();
   }
 
   DataExtractor::Cursor Cur(0);
   DataExtractor Data(Content, Obj.isLE(), /*AddressSize=*/0);
-  uint32_t NBucket = Data.getU32(Cur);
-  uint32_t NChain = Data.getU32(Cur);
+  uint64_t NBucket = Data.getU32(Cur);
+  uint64_t NChain = Data.getU32(Cur);
   if (Content.size() != (2 + NBucket + NChain) * 4) {
     S->Content = yaml::BinaryRef(Content);
     if (Cur)
       return S.release();
     llvm_unreachable("entries were not read correctly");
   }
 
   S->Bucket.emplace(NBucket);