Re: [PATCH 2/5] I2O: SPARC fixes

[Al Viro]

On Sun, Nov 20, 2005 at 11:07:14PM +0000, Al Viro wrote:
> 	And here's another fun one:
>                 evt->size = size;
>                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
>                 evt->event_indicator = le32_to_cpu(msg->body[0]);
>                 memcpy(&evt->tcntxt, &msg->u.s.tcntxt, size * 4);
> in i2o_driver_dispatch().

Gaaack...  Old code used to be
                       evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
                       if (!evt)
                               return -ENOMEM;
                       memset(evt, 0, size * 4 + sizeof(*evt));

                       evt->size = size;
                       memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt,
                                    (size + 2) * 4);

Then it became
               evt->size = size;
               evt->tcntxt = readl(&msg->u.s.tcntxt);
               evt->event_indicator = readl(&msg->body[0]);
               memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt, size * 4);

See the problem with it?  The last copy should be from &msg->body[1] to
evt->data.  As it is, we do not copy the last 8 bytes (which might or
might not be a problem) *AND* we overwrite tcntxt and event_indicator
with bus-endian values right after having host-endian ones carefully
assigned to them.

Breakage happened in
diff-tree 61fbfa8129c1771061a0e9f47747854293081c5b (from 34d6e07570ef74b96513145
Author: Markus Lidel <Markus.Lidel@xxxxxxxxxxxxxxxxx>
Date:   Thu Jun 23 22:02:11 2005 -0700

    [PATCH] I2O: bugfixes and compability enhancements

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/