[compiler-rt] [HWASan] Fix symbol indexing (PR #135967)

[Stefan Bossbaly via llvm-commits]

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@@ -76,19 +82,29 @@ def handle_elf(mv):
   # have to extend the parsing code.
   if mv[:6] != b'\x7fELF\x02\x01':
     return None
+  found_symbols = False
+  bid = None
   e_shnum, = struct.unpack_from('<H', buffer=mv, offset=e_shnum_offset)
   e_shoff, = struct.unpack_from('<Q', buffer=mv, offset=e_shoff_offset)
   for i in range(0, e_shnum):
     start = e_shoff + i * Shdr_size
-    sh_offset, sh_size = handle_Shdr(mv[start: start + Shdr_size])
-    if sh_offset is None:
-      continue
-    note_hdr = mv[sh_offset: sh_offset + sh_size]
-    result = handle_Nhdr(note_hdr, sh_size)
-    if result is not None:
-      return result
+    sh = mv[start: start + Shdr_size]
+    sh_type = unpack_sh_type(sh)
+
+    if sh_type == SHT_SYMTAB:
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StefanBossbaly wrote:

This was a quick way of telling me if the file was stripped, since when the `strip` command is run it will remove the `SYMTAB` section. This is how the `file` command reports if a ELF is stripped or not [1]. I have added logic that will read each section name to determine if ".debug_info" is present. The new logic does require us reading the shstr section since that is where the strings are stored so it does add a bit of complexity. Let me know what you think.

[1]: https://github.com/file/file/blob/f77a1092e1862c2295a21077c9e28c2614a0eede/src/readelf.c#L1479-L1484

https://github.com/llvm/llvm-project/pull/135967