Add comment about uniqueness of sections

src/compartment.c

@@ -569,6 +569,14 @@ parse_lib_file(char *lib_name, struct Compartment *new_comp)
     // corresponding symbols as 0, 4, and 8.
 
     // Traverse sections once to get headers for sections of interest
+    //
+    // XXX According to the ELF specification version 1.2, for UNIX, there are
+    // only one of each `SHT_SYMTAB`, `SHT_DYNSYM`, and `SHT_DYNAMIC`. Further,
+    // we assume there can only be one section with the name `.rela.plt`.
+    // Therefore, we expect each `if` to be only entered once. However, we not
+    // that this can be changed in future specifications.
+    //
+    // Source: https://refspecs.linuxfoundation.org/elf/elf.pdf
     const size_t headers_of_interest_count = 3;
     size_t found_headers = 0;
     Elf64_Shdr curr_shdr;