Valgrind has an embedded GDB server. That means it is possible to control a Valgrind run from GDB, doing all the usual things that GDB can do (single stepping, breakpoints, examining data, etc). Interactive Valgrind tool-specific functionality is available. For example, it is possible to query the definedness state of variables or memory from within GDB when running Memcheck; arbitrarily large memory watchpoints are supported; incremental leak search etc.

If time permits, a demo or description will be given for all or most or many or some of the below:

• basic use

  • how to activate the Valgrind gdbserver and connect GDB to it using the vgdb relay.
  • valgrind monitor command handling
  • Valgrind output redirection
  • List the errors (or last error) found by Valgrind

• Memcheck advanced functionalities

  • interactive leak search
  • display the addresses and content of leaked blocks
  • find who still has pointer(s) to a not freed piece of memory
  • arbitrary large memory watchpoints (unlimited 'simulated' hardware watchpoints)
  • examine or change the Accessibility and Validity bits
  • shadow registers examination

• Use vgdb to command Valgrind tools from the shell or from shell scripts.

• Other Valgrind tools interactive control

  • Massif memory snaphots
  • Dump or zero Callgrind counters

• Other Valgrind gdbserver "core" functionality

  • Threads state display
  • Display "leaked" file descriptors
  • Display some internal information about Valgrind
  • Limitations of the Valgrind gdbserver