Re: [Valgrind-users] improbably "uninitialized value" warning

[Tom H. <th...@cy...>]

In message <014f01c4a589$da94bd60$0401a8c0@dan>
          "Daniel Miller \(IMI\)" <da...@im...> wrote:

> Yeah, I get three of the following; I'm still trying to figure out what
> 0x4B30 is and what to do about them...
> 
> ==29190== Warning: noted but unhandled ioctl 0x4B30 with no size/direction
> hints
> ==29190==    This could cause spurious value errors to appear.
> ==29190==    See README_MISSING_SYSCALL_OR_IOCTL for guidance on writing a
> proper wrapper.
> 
> However, the usb_control_msg ioctl is 0x5530, not 0x4B30.  In any case, if
> usb_control_msg fails to get its data, it typically returns -1, and I don't
> use xbuf in that case, which is what I was referring to previously...

The problem is that if that ioctl returns some data and valgrind
does't realise then it won't mark that data as defined and the
effects will propagate through your program.

Tom

-- 
Tom Hughes (th...@cy...)
Software Engineer, Cyberscience Corporation
http://www.cyberscience.com/