Bug 280835

Version:           3.7 SVN (using KDE 4.7.0) 
OS:                Linux

This illegal opcode appears when calling xmlXPathInit() from within an application. Both libxml2-2.7.8 and my application are compiled and run on Intel Core i3-2310M CPU. Even when building a program, which only contains this single call, the problem arises. I was not able to narrow down the exact call within xmlXPathInit, which causes the problem, nor do i know which instruction these opcode refers to.

Valgrind SVN revision 12003.


Reproducible: Always

Steps to Reproduce:
Compile and link a program against libxml2, which calls xmlXPathInit()
Run this program with under valgrind.

Actual Results:  
==17277== Memcheck, a memory error detector
==17277== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==17277== Using Valgrind-3.7.0.SVN and LibVEX; rerun with -h for copyright info
==17277== Command: /home/jopen/test
==17277== 
vex amd64->IR: unhandled instruction bytes: 0xC5 0xF9 0x57 0xC0 0xC5 0xFB 0x10 0xD
==17277== valgrind: Unrecognised instruction at address 0x3f4e282890.
==17277==    at 0x3F4E282890: xmlXPathInit (in /usr/lib64/libxml2.so.2.7.8)
==17277==    by 0x400697: main (in /home/jopen/test)
==17277== Your program just tried to execute an instruction that Valgrind
==17277== did not recognise.  There are two possible reasons for this.
==17277== 1. Your program has a bug and erroneously jumped to a non-code
==17277==    location.  If you are running Memcheck and you just saw a
==17277==    warning about a bad jump, it's probably your program's fault.
==17277== 2. The instruction is legitimate but Valgrind doesn't handle it,
==17277==    i.e. it's Valgrind's fault.  If you think this is the case or
==17277==    you are not sure, please let us know and we'll try to fix it.
==17277== Either way, Valgrind will now raise a SIGILL signal which will
==17277== probably kill your program.
==17277== 
==17277== Process terminating with default action of signal 4 (SIGILL)
==17277==  Illegal opcode at address 0x3F4E282890
==17277==    at 0x3F4E282890: xmlXPathInit (in /usr/lib64/libxml2.so.2.7.8)
==17277==    by 0x400697: main (in /home/jopen/test)
==17277== 
==17277== HEAP SUMMARY:
==17277==     in use at exit: 0 bytes in 0 blocks
==17277==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==17277== 
==17277== All heap blocks were freed -- no leaks are possible
==17277== 
==17277== For counts of detected and suppressed errors, rerun with: -v
==17277== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)

Expected Results:  
Valgrind should recognize the used instructions.