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>
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 @@
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 @@
}
if (!for_insert)
return -ENOENT;
+ if (depth > FILTER_CTL_SRCH_MAX)
+ return -EBUSY;
found:
*depth_required = depth;
return filter_idx;