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

@@ -73,22 +73,29 @@
   _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);
+  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;

@@ -283,11 +290,12 @@
 }
 
 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) {
+  unsigned char *end = _lib->eh_frame.data + _lib->eh_frame.size;
+  while (_buf <= end) {
     uint64_t length = get_entry_length();
     if (length == 0L) {
       return false;
     }
     unsigned char *next_entry = _buf + length;

@@ -308,14 +316,14 @@
         uintptr_t augmentation_length = read_leb(false);
         _buf += augmentation_length; // skip
 
         // Process FDE
         parse_dwarf_instructions(pc_begin, pc, next_entry);
-        break;
+        return true;
       }
     }
 
     _buf = next_entry;
   }
 
-  return true;
+  return false;
 }