Re: [Valgrind-users] [2.4.0] Getting an "Access not within mapped region" in /lib/ld?

[Paul S. <ps...@no...>]

%% Jeremy Fitzhardinge <je...@go...> writes:

  jf> The only thing memcheck does which the other tools don't is check
  jf> the defined-ness of the arguments to syscalls, but that isn't
  jf> kernel-dependent in any way.  Does UML present a kernel ABI which
  jf> is identical to a native Linux kernel (same syscall interface,
  jf> etc)?

I believe so.  You can take stuff built for native Linux, even glibc,
and run it inside UML without recompiling it, assuming the userspace
libraries are compatible.

  jf> The other possibility is that UML presents a differently shaped
  jf> address space under different circumstances, which might confuse
  jf> things.  Are you building Valgrind with --enable-pie?  Probably
  jf> not, since you seem to be using fairly old systems.

I had to set --disable-pie, or else valgrind dumped core immediately
upon starting up.

  jf> Yes. 2.4.0 doesn't support helgrind, so I suspect it's picking up
  jf> a 2.2 helgrind.so file.

Yes, that's exactly what's happening.  I even know how.

  jf> It would be interesting to see what valgrind --tool=none cat
  jf> /proc/self/maps under each environment.

Ouch.  OK, after I've cleaned up my setup and recreated it with a less
chaotic environment, I've discovered that in reality ALL the tools cause
the core dump on the RHEW-hosted system, even --tool=none:

  # /opt/tools/bin/valgrind --tool=none /bin/echo hi
  ==1026== Nulgrind, a binary JIT-compiler for x86-linux.
  ==1026== Copyright (C) 2002-2004, and GNU GPL'd, by Nicholas Nethercote.
  ==1026== Using valgrind-2.4.0, a program supervision framework for x86-linux.
  ==1026== Copyright (C) 2000-2005, and GNU GPL'd, by Julian Seward et al.
  ==1026== For more details, rerun with: -v
  ==1026== 
  ==1026== 
  ==1026== Process terminating with default action of signal 11 (SIGSEGV): dumping core
  ==1026==  Access not within mapped region at address 0xBF7FFC61
  ==1026==    at 0x3A965A50: (within /lib/ld-2.3.2.so)
  ==1026== 
  Segmentation fault

Hm.  I must have been high on something (or, typing into the wrong
window) when I thought that the other tools all worked except for memcheck.

Bummer... :-/.

-- 
-------------------------------------------------------------------------------
 Paul D. Smith <ps...@no...>           HASMAT: HA Software Mthds & Tools
 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist
-------------------------------------------------------------------------------
   These are my opinions---Nortel Networks takes no responsibility for them.