[Valgrind-users] errors with libGL, __GL_FORCE_GENERIC_CPU doesn't help

[Alan <al...@me...>]

Hi,
I'm trying to use valgrind on a custom image processing program on a
laptop with RH 7.2, and NVidia GeForce2Go chipset, and NV's most recent
drivers (4496).

I get tons of errors from the libGL routines as expected, however
setting __GL_FORCE_GENERIC_CPU=1 doesn't seem to help at all!

I would test on something more standardized like "glxgears", but
unfortunately it isn't in my distribution (perish the thought of
upgrading X and all its dependencies from 4.1.0 to current!) and I
haven't seen a standalone package to build it from.

At the end of this email is the output from a valgrind run (with some
extraneous stuff clipped).

My questions:
1)  If the problem is related to the hardware-based libGL calls from the
NV drivers, is there a simple way to turn off hardware acceleration so
that valgrind would run without errors?
2)  Is this related to special CPU instructions?  Why doesn't
__GL_FORCE_GENERIC_CPU=1 seem to do anything?
3)  Is there a quick/easy way for me to build glxgears to make testing
valgrind on GL hardware a bit more uniform (eg, eliminates behavior
specific to my image processing program)?

Thanks for any insight into this problem and also for the all the effort 
on valgrind.

   --Alan


BTW, for the records, I don't have the "tls" directory tree.  The only
files are:

[root@ripple root]# locate libGL.
/usr/lib/libGL.so
/usr/lib/libGL.so.1.0.4496
/usr/lib/libGL.so.1

valgrind output follows:



[astein@ripple ~]$ valgrind display 0 0 0 1
==2551== Memcheck, a.k.a. Valgrind, a memory error detector for x86-linux.
==2551== Copyright (C) 2002-2003, and GNU GPL'd, by Julian Seward.
==2551== Using valgrind-20031012, a program supervision framework for
x86-linux.==2551== Copyright (C) 2000-2003, and GNU GPL'd, by Julian Seward.
==2551== Warning: set address range perms: large range 130834432, a 0, v 0
==2551== Estimated CPU clock rate is 996 MHz
==2551== For more details, rerun with: -v
==2551==
==2551== Syscall param modify_ldt(ptr)(func=1 or 0x11) contains
uninitialised or unaddressable byte(s)
==2551==    at 0x404F18D8: (within /usr/lib/libGL.so.1.0.4496)
==2551==    Address 0xBFFFF4C0 is on thread 1's stack
==2551==
...
==2551==
==2551== Syscall param ioctl(generic) contains uninitialised or
unaddressable byte(s)
==2551==    at 0x408AAAC4: __ioctl (in /lib/i686/libc-2.2.4.so)
==2551==    by 0x40511649: NvRmAllocRoot (in /usr/lib/libGL.so.1.0.4496)
==2551==    by 0x4050BC9E: (within /usr/lib/libGL.so.1.0.4496)
==2551==    Address 0xBFFFF120 is on thread 1's stack
==2551== Warning: set address range perms: large range 134217728, a 0, v 0
==2551==
==2551== Syscall param ioctl(generic) contains uninitialised or
unaddressable byte(s)
==2551==    at 0x408AAAC4: __ioctl (in /lib/i686/libc-2.2.4.so)
==2551==    by 0x405129E7: NvRmConfigGet (in /usr/lib/libGL.so.1.0.4496)
==2551==    by 0x4050BDCA: (within /usr/lib/libGL.so.1.0.4496)
==2551==    Address 0xBFFFF118 is on thread 1's stack
==2551==
...
==2551==
==2551== Syscall param ioctl(generic) contains uninitialised or
unaddressable byte(s)
==2551==    at 0x408AAAC4: __ioctl (in /lib/i686/libc-2.2.4.so)
==2551==    by 0x405129E7: NvRmConfigGet (in /usr/lib/libGL.so.1.0.4496)
==2551==    by 0x40BD5FBE: (within /usr/lib/libGLcore.so.1.0.4496)
==2551==    Address 0xBFFFF0CC is on thread 1's stack
==2551==
==2551== Syscall param ioctl(generic) contains uninitialised or
unaddressable byte(s)
==2551==    at 0x408AAAC4: __ioctl (in /lib/i686/libc-2.2.4.so)
==2551==    by 0x405129E7: NvRmConfigGet (in /usr/lib/libGL.so.1.0.4496)
==2551==    by 0x40BD600A: (within /usr/lib/libGLcore.so.1.0.4496)
==2551==    Address 0xBFFFF0CC is on thread 1's stack
...
==2551==
==2551== Syscall param ioctl(generic) contains uninitialised or
unaddressable byte(s)
==2551==    at 0x408AAAC4: __ioctl (in /lib/i686/libc-2.2.4.so)
==2551==    by 0x405121B7: NvRmFree (in /usr/lib/libGL.so.1.0.4496)
==2551==    by 0x40BC4300: __nvsym15143 (in usr/lib/libGLcore.so.1.0.4496)
==2551==    Address 0xBFFFF1D0 is on thread 1's stack
==2551==
==2551== ERROR SUMMARY: 3055 errors from 96 contexts (suppressed: 58 from 5)
==2551== malloc/free: in use at exit: 2340679 bytes in 4405 blocks.
==2551== malloc/free: 8945 allocs, 4540 frees, 4917877 bytes allocated.
==2551== For a detailed leak analysis,  rerun with: --leak-check=yes
==2551== For counts of detected errors, rerun with: -v
[astein@ripple ~]$