src/cpu/x86/vm/debug_x86.cpp

rev 7424 : improve secondary signal handling

*** 30,34 ****
--- 30,56 ----
  #include "runtime/os.hpp"
  #include "utilities/debug.hpp"
  #include "utilities/top.hpp"
  
  void pd_ps(frame f) {}
+ 
+ #ifndef PRODUCT
+ // return an instruction which will generate a SIGILL
+ bool get_illegal_instruction_sequence(uint8_t buf[8]) {
+   const uint8_t sequence[] = {
+ #if defined(AMD64)
+     // 06 => invalid instruction for x64
+     0x06
+ #else
+     // Note: privileged instructions won't work, because they cause a SIGSEGV 
+     // on Linux, not a SIGILL. "0f 0e" and "0f 0f" are invalid opcodes which 
+     // will cause real SIGILL resp. EXCEPTION_ILLEGAL_INSTRUCTION.
+     0x0f, 0x0f,
+     // in case this does not work, use a HLT which should be privilegued.
+     0xF4
+ #endif
+   };
+   memcpy(buf, sequence, sizeof(sequence));
+   return true;
+ }
+ #endif
+