Re: [libdc1394-devel] Valgrind and libdc1394 (Patch)

[Pablo A. M. <pal...@go...>]

Hello,

here is the patch for the 1.2.x version.  Most Valgrind warnings in our cod=
e=20
are now gone with the variable initializations made here.  The patch should=
=20
work with the version 1 in the repository.  Only the dc1394_control.c file=
=20
has been affected.

To apply it:

cd $(PATH_TO_YOUR)/libdc1394/branches/Version_1/libdc1394/libdc1394
cat dc1394_control.c.patch | patch -p0=20

Regards,

Pablo

On Sunday, 10 de December de 2006 11:21, Pablo Alvarado Moya wrote:
> Hello everybody,
>
> I'm improving a wrapper class for the libdc1394 in the LTI-Lib (image
> processing library), and while testing my classes for memory leaks and
> alike using Valgrind, I found that the libdc1394 version 1.2.1 (the one on
> SourceForge) generates lots of dangerous warnings like:
>
> Conditional jump or move depends on uninitialised value(s)
> =3D=3D22706=3D=3D    at 0x4332CD4: GetConfigROMTaggedRegister
> (dc1394_control.c:878) =3D=3D22706=3D=3D    by 0x43332EC: dc1394_get_came=
ra_info
> (dc1394_control.c:1360) ...
>
> Otherwise than the compiler, Valgrind has detected that the condition in
> the "if"s is really based on uninitialized values.  Some of the warnings
> can be avoided initializing all attributes of the structures used, before
> calling any dc1394_* function, but others are based on internal unitializ=
ed
> variables within the library.
>
> Would it be possible in the function (in dc1394_control.c)
>
> int GetCameraControlRegister(raw1394handle_t handle, nodeid_t node,
>                                              octlet_t offset,quadlet_t
> *value)
>
> to force at the beginning *value=3D0 ?  This would eliminate many of the
> warnings, as the cases in which value isn't touched will provide somethin=
g.
> (This is a critical case, I could also change the many cases which call
> this function and force them to initialize value instead).
>
> Also in int dc1394_get_camera_info(...) many warnings are produced since
>
> quadlet_t value[2], quadval;
>
> are not initialized.
>
> I can create a patch if anybody is interested in.  However, I wanted to as
> if those initializations have implications that I overlook.
>
> Regards,
>
> Pablo

=2D-=20
Dr. Pablo Alvarado                      E-Mail: pal...@ie...
Escuela de Ingenier=EDa Electr=F3nica       Tel.:   (+506) 550 2106
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