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authorBen Hutchings <bhutchings@solarflare.com>2010-10-08 10:36:10 -0700
committerDavid S. Miller <davem@davemloft.net>2010-10-08 10:36:10 -0700
commit993284dfff3ba4643f08b592427d0ac758d30156 (patch)
treee929f5e896bb71d33eca2a6b21774ae93d051344
parent4e7f79511e7332ae4056eda9156a0299511ea41e (diff)
sfc: Don't try to set filters with search depths we know won't work
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 <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/sfc/filter.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/net/sfc/filter.c b/drivers/net/sfc/filter.c
index abc884d09d57..52cb6082b910 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;