Re: [Valgrind-users] Handling ioctl 0x30000001 in valgrind?

[Tom H. <to...@co...>]

On 19/05/15 17:26, Carl Ponder wrote:

> So it shuts off the warning message
>
>     *==21898== Warning: noted but unhandled ioctl 0x30000001 with no
>     size/direction hints.*
>     ==21898==   This could cause spurious value errors to appear.
>     ==21898==   See README_MISSING_SYSCALL_OR_IOCTL for guidance on
>     writing a proper wrapper.
>
> but doesn't do anything to manage the memory state.
> The output I'm getting from--trace-syscalls=yes is
>
>     SYSCALL[20867,1](16) *sys_ioctl ( 38, 0x30000001, 0x0 *) --> [async]
>     ...
>     SYSCALL[20867,1](16) ... [async] --> Success(0x0:0x0)
>
> so it doesn't look like any memory-range is being passed in.
> I'm checking with our engineers to see if there is any special
> processing that needs to happen here, and we'll also have to watch and
> see if any other NVIDIA-specific calls are happening.

Yes you will need to find out if it reads/writes any memory, though it 
looks unlikely in this case.

> One question to you: does it make sense to be hard-coding the
> *0x30000001* case into the generalioctl handler, or should there be an
> NVIDIA-specific file in the coregrind/m_syswrap directory?
> Thanks,

Well I'm not sure there's much precedent as we don't normally take 
system calls that aren't in the upstream kernel. There may be a few ARM 
ones as precedent.

Tom

-- 
Tom Hughes (to...@co...)
http://compton.nu/