Stephen Hemminger wrote:
On Tue, 28 Feb 2006 13:56:57 -0500
Jeff Garzik <[EMAIL PROTECTED]> wrote:
Stephen Hemminger wrote:
This trivial patch can go in the netdev can for 2.6.17.
It lets skge driver contribute to random entropy poll.
Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
--- sky2.orig/drivers/net/skge.c 2006-02-27 10:00:48.000000000 -0800
+++ sky2/drivers/net/skge.c 2006-02-28 10:35:48.000000000 -0800
@@ -3314,7 +3314,9 @@
goto err_out_free_hw;
}
- if ((err = request_irq(pdev->irq, skge_intr, SA_SHIRQ, DRV_NAME, hw))) {
+ err = request_irq(pdev->irq, skge_intr, SA_SHIRQ | SA_SAMPLE_RANDOM,
+ DRV_NAME, hw);
The traditional objection to this is that the sampling is _not_ random,
if you are a remote attacker, carefully timing your packets...
tg3 and e1000 do it, as does sky2, but I'm still not convinced its safe.
I guess the problem comes down to the resolution of the clock used
for sampling. Right now with 250hz, it isn't really fast to be a good
entropy source on any network card.
Oh yeah, another aspect: cards with hardware interrupt mitigation
should NOT use SA_SAMPLE_RANDOM, for obvious reasons... Anything that
has the potential to have non-random timings should be avoided.
Jeff
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