8295646: Ignore zero pairs in address descriptors read by dwarf parser

Reviewed-by: chagedorn

Author: zhengxiaolinX

Diff for: src/hotspot/share/utilities/elfFile.cpp

@@ -763,6 +763,8 @@ bool DwarfFile::DebugAranges::read_set_header(DebugArangesSetHeader& header) {
     return false;
   }
 
+  _entry_end = _reader.get_position() + header._unit_length;
+
   if (!_reader.read_word(&header._version) || header._version != 2) {
     // DWARF 4 uses version 2 as specified in Appendix F of the DWARF 4 spec.
     DWARF_LOG_ERROR(".debug_aranges in unsupported DWARF version %" PRIu16, header._version)
@@ -803,7 +805,7 @@ bool DwarfFile::DebugAranges::read_address_descriptors(const DwarfFile::DebugAra
       found_matching_set = true;
       return true;
     }
-  } while (!is_terminating_entry(descriptor) && _reader.has_bytes_left());
+  } while (!is_terminating_entry(header, descriptor) && _reader.has_bytes_left());
 
   // Set does not match offset_in_library. Continue with next.
   return true;
@@ -819,8 +821,12 @@ bool DwarfFile::DebugAranges::does_match_offset(const uint32_t offset_in_library
          && offset_in_library < descriptor.beginning_address + descriptor.range_length;
 }
 
-bool DwarfFile::DebugAranges::is_terminating_entry(const AddressDescriptor& descriptor) {
-  return descriptor.beginning_address == 0 && descriptor.range_length == 0;
+bool DwarfFile::DebugAranges::is_terminating_entry(const DwarfFile::DebugAranges::DebugArangesSetHeader& header,
+                                                   const AddressDescriptor& descriptor) {
+  bool is_terminating = _reader.get_position() >= _entry_end;
+  assert(!is_terminating || (descriptor.beginning_address == 0 && descriptor.range_length == 0),
+         "a terminating entry needs a pair of zero");
+  return is_terminating;
 }
 
 // Find the .debug_line offset for the line number program by reading from the .debug_abbrev and .debug_info section.

Diff for: src/hotspot/share/utilities/elfFile.hpp

@@ -485,15 +485,20 @@ class DwarfFile : public ElfFile {
     MarkedDwarfFileReader _reader;
     uint32_t _section_start_address;
 
+    // a calculated end position
+    long _entry_end;
+
     bool read_section_header();
     bool read_set_header(DebugArangesSetHeader& header);
     bool read_address_descriptors(const DwarfFile::DebugAranges::DebugArangesSetHeader& header,
                                   uint32_t offset_in_library, bool& found_matching_set);
     bool read_address_descriptor(AddressDescriptor& descriptor);
     static bool does_match_offset(uint32_t offset_in_library, const AddressDescriptor& descriptor) ;
-    static bool is_terminating_entry(const AddressDescriptor& descriptor);
+    bool is_terminating_entry(const DwarfFile::DebugAranges::DebugArangesSetHeader& header,
+                              const AddressDescriptor& descriptor);
    public:
-    DebugAranges(DwarfFile* dwarf_file) : _dwarf_file(dwarf_file), _reader(dwarf_file->fd()), _section_start_address(0) {}
+    DebugAranges(DwarfFile* dwarf_file) : _dwarf_file(dwarf_file), _reader(dwarf_file->fd()),
+                                          _section_start_address(0), _entry_end(0) {}
     bool find_compilation_unit_offset(uint32_t offset_in_library, uint32_t* compilation_unit_offset);
 
   };