Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756543Ab3CZXMi (ORCPT ); Tue, 26 Mar 2013 19:12:38 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:53361 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756734Ab3CZXB7 (ORCPT ); Tue, 26 Mar 2013 19:01:59 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Hutchings Subject: [ 09/49] sfc: Fix loop condition for efx_filter_search() when !for_insert Date: Tue, 26 Mar 2013 16:01:06 -0700 Message-Id: <20130326225840.544786691@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130326225839.554028294@linuxfoundation.org> References: <20130326225839.554028294@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2863 Lines: 90 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings [ Upstream commit 4017dbdc14af1903dc9fcba4d08b89c02325069d ] efx_filter_remove_filter() fails to remove inserted filters in some cases. For example: 1. Two filters A and B have specifications that result in an initial hash collision. 2. A is inserted first, followed by B. 3. An attempt to remove B first succeeds, but if A is removed first a subsequent attempt to remove B fails. When searching for an existing filter (!for_insert), efx_filter_search() must always continue to the maximum search depth for the given type rather than stopping at the first unused entry. Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/net/sfc/filter.c | 39 +++++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 16 deletions(-) --- a/drivers/net/sfc/filter.c +++ b/drivers/net/sfc/filter.c @@ -335,28 +335,35 @@ static int efx_filter_search(struct efx_ bool for_insert, int *depth_required) { unsigned hash, incr, filter_idx, depth, depth_max; - struct efx_filter_spec *cmp; hash = efx_filter_hash(key); incr = efx_filter_increment(key); - depth_max = (spec->priority <= EFX_FILTER_PRI_HINT ? - FILTER_CTL_SRCH_HINT_MAX : FILTER_CTL_SRCH_MAX); - for (depth = 1, filter_idx = hash & (table->size - 1); - depth <= depth_max && test_bit(filter_idx, table->used_bitmap); - ++depth) { - cmp = &table->spec[filter_idx]; - if (efx_filter_equal(spec, cmp)) - goto found; + filter_idx = hash & (table->size - 1); + depth = 1; + depth_max = (for_insert ? + (spec->priority <= EFX_FILTER_PRI_HINT ? + FILTER_CTL_SRCH_HINT_MAX : FILTER_CTL_SRCH_MAX) : + table->search_depth[spec->type]); + + for (;;) { + /* Return success if entry is used and matches this spec + * or entry is unused and we are trying to insert. + */ + if (test_bit(filter_idx, table->used_bitmap) ? + efx_filter_equal(spec, &table->spec[filter_idx]) : + for_insert) { + *depth_required = depth; + return filter_idx; + } + + /* Return failure if we reached the maximum search depth */ + if (depth == depth_max) + return for_insert ? -EBUSY : -ENOENT; + filter_idx = (filter_idx + incr) & (table->size - 1); + ++depth; } - if (!for_insert) - return -ENOENT; - if (depth > depth_max) - return -EBUSY; -found: - *depth_required = depth; - return filter_idx; } /* Construct/deconstruct external filter IDs */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/