[Valgrind-users] VEX : unhandled instruction bytes

[Chris J. <jo...@he...>]

Hi,

I have an application that is causing valgrind to seg. fault, but runs 
just fine natively. The seg. fault is below. This is using the SVN trunk 
build of valgrind as of an hour or so ago (revision 14231).

The primary message to me seems to be

vex amd64->IR: unhandled instruction bytes: 0xFF 0xFF 0xFF 0xFF 0xFF 
0xFF 0xFF 0xFF
vex amd64->IR:   REX=0 REX.W=0 REX.R=0 REX.X=0 REX.B=0
vex amd64->IR:   VEX=0 VEX.L=0 VEX.nVVVV=0x0 ESC=NONE
vex amd64->IR:   PFX.66=0 PFX.F2=0 PFX.F3=0

http://valgrind.org/docs/manual/faq.html

Seems to suggest this could be one of two things; an error in the 
application (but then it runs fine outside valgrind) or an error in 
valgrind. Does anyone have any insights into which one this is here ?

cheers Chris

==23684== Jump to the invalid address stated on the next line
==23684==    at 0x2F769650: ???
==23684==    by 0xFFEFEFFEF: ???
==23684==    by 0x13E72601: ???
==23684==    by 0x1151A3FF: ???
==23684==    by 0x12E89588: clang::Decl::getASTContext() const (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libCling.so)
==23684==    by 0xFFEFF047F: ???
==23684==    by 0xFFEFF0197: ???
==23684==    by 0x212E92D91: ???
==23684==  Address 0x2f769650 is 0 bytes inside a block of size 32 alloc'd
==23684==    at 0x4A07FD5: operator new(unsigned long) 
(vg_replace_malloc.c:326)
==23684==    by 0x13E725DB: ???
==23684==    by 0x125E3AE5: TClingCallFunc::exec(void*, void*) const (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libCling.so)
==23684==    by 0x125E4E28: 
TClingCallFunc::exec_with_valref_return(void*, cling::Value*) const (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libCling.so)
==23684==    by 0x125E7852: long TClingCallFunc::ExecT<long>(void*) (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libCling.so)
==23684==    by 0xE98106F: PyROOT::TMethodHolder::CallSafe(void*, bool) 
(in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libPyROOT.so)
==23684==    by 0xE97EFAC: PyROOT::TMethodHolder::Execute(void*, bool) 
(in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libPyROOT.so)
==23684==    by 0xE99B1CF: 
PyROOT::TConstructorHolder::operator()(PyROOT::ObjectProxy*, _object*, 
_object*, long, bool) (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libPyROOT.so)
==23684==    by 0xE9738E9: PyROOT::(anonymous 
namespace)::mp_call(PyROOT::MethodProxy*, _object*, _object*) (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libPyROOT.so)
==23684==    by 0x4C637A2: PyObject_Call (abstract.c:2529)
==23684==    by 0x4CCEC7E: slot_tp_init (typeobject.c:5692)
==23684==    by 0x4CCD7FE: type_call (typeobject.c:745)
==23684==
vex amd64->IR: unhandled instruction bytes: 0xFF 0xFF 0xFF 0xFF 0xFF 
0xFF 0xFF 0xFF
vex amd64->IR:   REX=0 REX.W=0 REX.R=0 REX.X=0 REX.B=0
vex amd64->IR:   VEX=0 VEX.L=0 VEX.nVVVV=0x0 ESC=NONE
vex amd64->IR:   PFX.66=0 PFX.F2=0 PFX.F3=0
==23684== Invalid read of size 1
==23684==    at 0x2F76965D: ???
==23684==    by 0xFFEFEFFEF: ???
==23684==    by 0x13E72601: ???
==23684==    by 0x1151A3FF: ???
==23684==    by 0x12E89588: clang::Decl::getASTContext() const (in 
/afs/cern.ch/sw/lcg/releases/ROOT/6.00.02-1c3e2/x86_64-slc6-gcc48-opt/lib/libCling.so)
==23684==    by 0xFFEFF047F: ???
==23684==    by 0xFFEFF0197: ???
==23684==    by 0x212E92D91: ???
==23684==  Address 0x1151a4 is not stack'd, malloc'd or (recently) free'd
==23684==

  *** Break *** segmentation violation
#0  vgModuleLocal_do_syscall_for_client_WRK () at 
m_syswrap/syscall-amd64-linux.S:147
#1  0x0000000000000008 in ?? ()
#2  0x0000000802c9ddd0 in ?? ()
#3  0x0000000802c9dd90 in ?? ()
#4  0x0000000039c2b950 in vgPlain_threads ()
#5  0x000000000000003d in ?? ()
#6  0x0000000039c2b940 in vgPlain_threads ()
#7  0x000000003a0154c8 in syscallInfo ()
#8  0x00000000000000b8 in ?? ()
#9  0x000000000000003d in ?? ()
#10 0x0000000000000001 in ?? ()
#11 0x000000003a015438 in syscallInfo ()
#12 0x00000000380a4acb in vgPlain_client_syscall ()
#13 0x00000000380a1483 in handle_syscall ()
#14 0x00000000380a2cb7 in vgPlain_scheduler ()
#15 0x00000000380b20ed in run_a_thread_NORETURN () at 
m_syswrap/syswrap-linux.c:103
#16 0x0000000000000000 in ?? ()
==23684==
==23684== HEAP SUMMARY:
==23684==     in use at exit: 400,342,711 bytes in 324,405 blocks
==23684==   total heap usage: 1,706,725 allocs, 1,382,320 frees, 
1,290,641,013 bytes allocated
==23684==
==23684== LEAK SUMMARY:
==23684==    definitely lost: 16,272 bytes in 165 blocks
==23684==    indirectly lost: 74,905 bytes in 446 blocks
==23684==      possibly lost: 2,997,955 bytes in 40,606 blocks
==23684==    still reachable: 381,943,798 bytes in 264,556 blocks
==23684==         suppressed: 15,309,781 bytes in 18,632 blocks
==23684== Rerun with --leak-check=full to see details of leaked memory
==23684==
==23684== For counts of detected and suppressed errors, rerun with: -v
==23684== Use --track-origins=yes to see where uninitialised values come 
from
==23684== ERROR SUMMARY: 83 errors from 5 contexts (suppressed: 1440 
from 192)

p.s. libCling.so is an library based on the Clang 3.5 compiler that 
provides an interactive compiler environment.