From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: [PATCH net-next-2.6] sfc: Don't try to set filters with search depths we know won't work Date: Thu, 07 Oct 2010 18:50:31 +0100 Message-ID: <1286473831.2271.26.camel@achroite.uk.solarflarecom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-net-drivers@solarflare.com To: David Miller Return-path: Received: from mail.solarflare.com ([216.237.3.220]:32951 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753822Ab0JGRue (ORCPT ); Thu, 7 Oct 2010 13:50:34 -0400 Sender: netdev-owner@vger.kernel.org List-ID: The filter engine will time-out and ignore filters beyond 200-something hops. We also need to avoid infinite loops in efx_filter_search() when the table is full. Signed-off-by: Ben Hutchings --- drivers/net/sfc/filter.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-) diff --git a/drivers/net/sfc/filter.c b/drivers/net/sfc/filter.c index abc884d..52cb608 100644 --- a/drivers/net/sfc/filter.c +++ b/drivers/net/sfc/filter.c @@ -20,6 +20,12 @@ #define FILTER_CTL_SRCH_FUDGE_WILD 3 #define FILTER_CTL_SRCH_FUDGE_FULL 1 +/* Hard maximum hop limit. Hardware will time-out beyond 200-something. + * We also need to avoid infinite loops in efx_filter_search() when the + * table is full. + */ +#define FILTER_CTL_SRCH_MAX 200 + struct efx_filter_table { u32 offset; /* address of table relative to BAR */ unsigned size; /* number of entries */ @@ -183,7 +189,8 @@ static int efx_filter_search(struct efx_filter_table *table, incr = efx_filter_increment(key); for (depth = 1, filter_idx = hash & (table->size - 1); - test_bit(filter_idx, table->used_bitmap); + depth <= FILTER_CTL_SRCH_MAX && + test_bit(filter_idx, table->used_bitmap); ++depth) { cmp = &table->spec[filter_idx]; if (efx_filter_equal(spec, cmp)) @@ -192,6 +199,8 @@ static int efx_filter_search(struct efx_filter_table *table, } if (!for_insert) return -ENOENT; + if (depth > FILTER_CTL_SRCH_MAX) + return -EBUSY; found: *depth_required = depth; return filter_idx; -- 1.7.2.1 -- Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.