Re: [PATCH] umad.c: memset() ib_user_mad_reg_req structure to 0 beforeinvoking ioctl()

[sebastien dugue <sebastien.dugue-6ktuUTfB/bM@public.gmane.org>]

On Tue, 05 Jul 2011 07:41:17 -0400
Hal Rosenstock <hal-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> wrote:

> On 7/4/2011 5:53 AM, sebastien dugue wrote:
> > 
> > This fixes the following warning issued by valgrind:
> > 
> > ==5287== Syscall param ioctl(generic) points to uninitialised byte(s)
> > ==5287==    at 0x3C466D95D7: ioctl (in /lib64/libc-2.12.so)
> > ==5287==    by 0x526C292: umad_register (umad.c:947)
> > ==5287==    by 0x568D206: smp_engine_init (query_smp.c:228)
> > ==5287==    by 0x5689F8F: ibnd_discover_fabric (ibnetdisc.c:537)
> > ==5287==    by 0x411700: devmgr_discover_fabric (devmgr_discover.c:66)
> > 
> > Signed-off-by: Jean-Vincent Ficet <jean-vincent.ficet-6ktuUTfB/bM@public.gmane.org>
> > 
> > ---
> > 
> > diff --git a/src/umad.c b/src/umad.c
> > index 45a9423..cac46a4 100644
> > --- a/src/umad.c
> > +++ b/src/umad.c
> > @@ -892,6 +892,7 @@ int umad_register_oui(int fd, int mgmt_class, uint8_t rmpp_version,
> >  		return -EINVAL;
> >  	}
> >  
> > +	memset(&req, 0, sizeof(req));
> >  	req.qpn = 1;
> >  	req.mgmt_class = mgmt_class;
> >  	req.mgmt_class_version = 1;
> > @@ -928,6 +929,7 @@ int umad_register(int fd, int mgmt_class, int mgmt_version,
> >  	    ("fd %d mgmt_class %u mgmt_version %u rmpp_version %d method_mask %p",
> >  	     fd, mgmt_class, mgmt_version, rmpp_version, method_mask);
> >  
> > +	memset(&req, 0, sizeof(req));
> >  	req.qpn = qp = (mgmt_class == 0x1 || mgmt_class == 0x81) ? 0 : 1;
> >  	req.mgmt_class = mgmt_class;
> >  	req.mgmt_class_version = mgmt_version;
> 
> I think this is a "false positive" in valgrind. memset of the request
> isn't really needed for either of these APIs as all input fields are
> filled in by the caller and the only one which isn't is id which is an
> output field.

  Ok then, it's no needed.

  Thanks,

  Sébastien.

> 
> -- Hal
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