0.4.2 (Dec 20th, 2013)

Kernel release:

3.8.13-22.el6uek

New features:

• SDT probe points in kernel modules are now supported.

• The 'vtimestamp' D variable has been implemented.

Bugfixes:

• Kill -9'ing a running dtrace will no longer leave breakpoints outstanding in processes with no controlling terminal that were grabbed as a side effect of ustack(), usym(), uaddr() or umod); as a side effect, symbol resolution will be less accurate for such processes. Grabbing a process with no controlling terminal via dtrace -p restores full symbol resolution accuracy for these processes, at the cost of dropping breakpoints in them again. Processes with a controlling terminal are still treated as in prior releases.

• ustack(), usym(), uaddr() and umod() of multithreaded processes no longer crashes the system, oopses the kernel, hangs the process being probed, crashes dtrace(1) itself, or runs dtrace or the system as a whole out of filehandles.

• Interrupting dtrace with a SIGINT while monitored processes are dying simultaneously now consistently stops it rather than hanging forever.

• dtrace's symbol-resolution paths are armoured against various problems which could occur when processes died while lookups were underway.

• pid and ppid are now correctly derived for multithreaded processes, pointing to the POSIX pid and parent respectively rather than the thread and thread group leader.

• Resolving kernel symbols located at the start of modules will no longer cause dtrace userspace to dereference uninitialized memory as a pointer.