On Wed, Jan 11, 2012 at 11:36:11AM +1100, Herbert Xu wrote: > On Wed, Jan 11, 2012 at 03:00:40AM +0300, Alexey Dobriyan wrote: > > commit f9e2bca6c22d75a289a349f869701214d63b5060 > > aka "crypto: sha512 - Move message schedule W[80] to static percpu area" > > created global message schedule area. > > > > If sha512_update will ever be entered twice, hilarity ensures. > > Hmm, do you know why this happens? On the face of it this shouldn't > be possible as preemption is disabled. >
I did not try to reproduce, but this looks like a race of the 'local out' and the receive packet path. On 'lokal out' bottom halves are enabled, so could be interrupted by the NET_RX_SOFTIRQ while doing a sha512_update. The NET_RX_SOFTIRQ could invoke sha512_update too, that would corrupt the hash value. My guess could be checked easily by disabling the bottom halves before the percpu value is fetched. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
