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

From: Markus Lidel
Date: Sun Nov 20 2005 - 19:48:51 EST


Al Viro wrote:
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

At the moment it's not a problem, because the event system is not used...

with bus-endian values right after having host-endian ones carefully
assigned to them.

Yep, you're right... the memcpy_fromio is wrong... It should be:

memcpy_fromio(&evt->body[1], &msg->body[1], size * 4);

as you already mentioned...

Thanks for your help.

Best regards,

Markus Lidel
Markus Lidel (Senior IT Consultant)

Shadow Connect GmbH
Carl-Reisch-Weg 12
D-86381 Krumbach

Phone: +49 82 82/99 51-0
Fax: +49 82 82/99 51-11

E-Mail: Markus.Lidel@xxxxxxxxxxxxxxxxx
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