Bug 1366574

Created attachment 1190350 [details]
trace-only.cpp

You can turn off library tracking by default:

  #include <dyninst/PlatFeatures.h>
  ...
  {
    Dyninst::ProcControlAPI::LibraryTracking::setDefaultTrackLibraries(false);
  }

Then for a given Process, you can refresh manually with:

    proc->getLibraryTracking()->refreshLibraries();

Does that suffice for you?

AFAICS the various "tracking" APIs are not discussed at all in proccontrol.pdf though, so that's probably worth raising upstream.

A global variable?  Not really nice, but it works for me.

Sorry, it seems that

  Dyninst::ProcControlAPI::LibraryTracking::setDefaultTrackLibraries(false);

at the start of the program is not fully effective.  I still see

30217 ptrace(PTRACE_PEEKTEXT, 28519, 0x7fb3508500a0, [0x2e6666666666c3f3]) = 0
30217 ptrace(PTRACE_POKETEXT, 28519, 0x7fb3508500a0, 0x2e6666666666c3cc) = 0

with it.  This is not related to library tracking, but something else.  GDB shows this as the location of the crash:

Dump of assembler code for function __nptl_create_event:
   0x00007fb3508500a0 <+0>:	int3   
=> 0x00007fb3508500a1 <+1>:	retq   

Looking at the Dyninst sources, this does not appear to be optional.

(The Dyninst manual could also be a bit more explicit and describe how to deallocate a Process object so that the traced process does not crash later on.)

Those new breakpoints are coming from thread_db_process::initThreadDB() for TD_CREATE and TD_DESTROY events.

I filed an upstream bug about wanting a true read-only mode.
https://github.com/dyninst/dyninst/issues/181

As just pointed out in upstream 181, there actually is a control for threads too:

  Dyninst::ProcControlAPI::ThreadTracking::setDefaultTrackThreads(false);

And manual refresh is similarly:

  proc->getThreadTracking()->refreshThreads();

I'm not sure how we both overlooked that.  It seems to work for me -- I now see no calls to ptrace(PTRACE_POKETEXT,...) nor to process_vm_writev(...).

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

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