[openib-general] Re: Questions about libibat, ib_uat, and ib_a

[Pradeep Satyanarayana]

openib-general-bounces at openib.org wrote on 10/18/2005 03:40:47 PM:

>
>
>
>
> On Mon, 2005-10-18 at 10:07, Kevin Reilly wrote:
> >On Mon, 2005-10-17 at 10:07, Hal Rosenstock wrote:
> >> > Should this code work, because it seems that out_dev is a kernel
> >> > address (platform: PPC64) which cannot accessed  by a userspace
> >> > program. Via GDB I can see that rt has the following content:
> >> >
> >> > The address is rt->out_dev = 0xc0000000cffaa800 which looks like a
> >> > kernel address.
> >>
> >> Yes, this is a bug which has been previously pointed out on the list
and
> >> not fixed.
> >

Can some one point me to the previous discussions on this list (search did
not yield any
results)? The problem is because of a copy_to_user (in uat.c) between
struct ib_at_ib_route
which are different between user and kernel space causing this crash.
What was the rationale of putting a pointer to struct ibv_device in the
user space version of
ib_at_ib_route? The out_dev field in user space is not really used as far
as I could see.

> >The fix for this involves an ABI change: it should return the GID of the
> >outgoing IB device.
> >

Would a simple solution like adding a device_name field to both the
ib_at_ib_route structures
be acceptable? The out_dev field could be used as a "reserved" field in
user space and not be used.
That should not break anything as far as I can see.


> >-- Hal

Pradeep
pradeep at us.ibm.com
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