src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp

*** 73,94 ****
    _buf += 4; // Skip ID (This value of CIE would be always 0)
    _buf++;    // Skip version (assume to be "1")
  
    char *augmentation_string = reinterpret_cast<char *>(_buf);
    bool has_ehdata = (strcmp("eh", augmentation_string) == 0);
-   bool fde_encoded = (strchr(augmentation_string, 'R') != NULL);
    _buf += strlen(augmentation_string) + 1; // includes '\0'
    if (has_ehdata) {
      _buf += sizeof(void *); // Skip EH data
    }
  
    _code_factor = read_leb(false);
    _data_factor = static_cast<int>(read_leb(true));
    _return_address_reg = static_cast<enum DWARF_Register>(*_buf++);
  
!   if (fde_encoded) {
!     uintptr_t augmentation_length = read_leb(false);
      _encoding = *_buf++;
    }
  
    // Clear state
    _current_pc = 0L;
--- 73,101 ----
    _buf += 4; // Skip ID (This value of CIE would be always 0)
    _buf++;    // Skip version (assume to be "1")
  
    char *augmentation_string = reinterpret_cast<char *>(_buf);
    bool has_ehdata = (strcmp("eh", augmentation_string) == 0);
    _buf += strlen(augmentation_string) + 1; // includes '\0'
    if (has_ehdata) {
      _buf += sizeof(void *); // Skip EH data
    }
  
    _code_factor = read_leb(false);
    _data_factor = static_cast<int>(read_leb(true));
    _return_address_reg = static_cast<enum DWARF_Register>(*_buf++);
  
!   if (strpbrk(augmentation_string, "LP") != NULL) {
!     // Language personality routine (P) and LSDA (L) are not supported
!     // because we need compliant Unwind Library Interface,
!     // but we want to unwind without it.
!     //
!     //   Unwind Library Interface (SysV ABI AMD64 6.2)
!     //     https://software.intel.com/sites/default/files/article/402129/mpx-linux64-abi.pdf
!     return false;
!   } else if (strchr(augmentation_string, 'R') != NULL) {
!     read_leb(false); // augmentation length
      _encoding = *_buf++;
    }
  
    // Clear state
    _current_pc = 0L;
*** 283,293 ****
  }
  
  bool DwarfParser::process_dwarf(const uintptr_t pc) {
    // https://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html
    _buf = _lib->eh_frame.data;
!   while (true) {
      uint64_t length = get_entry_length();
      if (length == 0L) {
        return false;
      }
      unsigned char *next_entry = _buf + length;
--- 290,300 ----
  }
  
  bool DwarfParser::process_dwarf(const uintptr_t pc) {
    // https://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html
    _buf = _lib->eh_frame.data;
!   while (_buf <= (_buf + _lib->eh_frame.size)) {
      uint64_t length = get_entry_length();
      if (length == 0L) {
        return false;
      }
      unsigned char *next_entry = _buf + length;
*** 308,321 ****
          uintptr_t augmentation_length = read_leb(false);
          _buf += augmentation_length; // skip
  
          // Process FDE
          parse_dwarf_instructions(pc_begin, pc, next_entry);
!         break;
        }
      }
  
      _buf = next_entry;
    }
  
!   return true;
  }
--- 315,328 ----
          uintptr_t augmentation_length = read_leb(false);
          _buf += augmentation_length; // skip
  
          // Process FDE
          parse_dwarf_instructions(pc_begin, pc, next_entry);
!         return true;
        }
      }
  
      _buf = next_entry;
    }
  
!   return false;
  }