[PATCH v7 3/4] net: dropreason: use new __print_sym() in tracing

@@ -42,6 +42,11 @@ struct drop_reason_list {
 extern const struct drop_reason_list __rcu *
 drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM];
 
+#ifdef CONFIG_TRACEPOINTS
+const char *drop_reason_lookup(unsigned long long value);
+void drop_reason_show(struct seq_file *m);
+#endif
+
 void drop_reasons_register_subsys(enum skb_drop_reason_subsys subsys,
 				  const struct drop_reason_list *list);
 void drop_reasons_unregister_subsys(enum skb_drop_reason_subsys subsys);

@@ -8,15 +8,9 @@
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
 #include <linux/tracepoint.h>
+#include <net/dropreason.h>
 
-#undef FN
-#define FN(reason)	TRACE_DEFINE_ENUM(SKB_DROP_REASON_##reason);
-DEFINE_DROP_REASON(FN, FN)
-
-#undef FN
-#undef FNe
-#define FN(reason)	{ SKB_DROP_REASON_##reason, #reason },
-#define FNe(reason)	{ SKB_DROP_REASON_##reason, #reason }
+TRACE_DEFINE_SYM_FNS(drop_reason, drop_reason_lookup, drop_reason_show);
 
 /*
  * Tracepoint for free an sk_buff:

@@ -47,8 +41,7 @@ TRACE_EVENT(kfree_skb,
 	TP_printk("skbaddr=%p rx_sk=%p protocol=%u location=%pS reason: %s",
 		  __entry->skbaddr, __entry->rx_sk, __entry->protocol,
 		  __entry->location,
-		  __print_symbolic(__entry->reason,
-				   DEFINE_DROP_REASON(FN, FNe)))
+		  __print_sym(__entry->reason, drop_reason))
 );
 
 #undef FN

@@ -154,6 +154,49 @@ drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM] = {
 };
 EXPORT_SYMBOL(drop_reasons_by_subsys);
 
+#ifdef CONFIG_TRACEPOINTS
+const char *drop_reason_lookup(unsigned long long value)
+{
+	unsigned long long subsys_id = value >> SKB_DROP_REASON_SUBSYS_SHIFT;
+	u32 reason = value & ~SKB_DROP_REASON_SUBSYS_MASK;
+	const struct drop_reason_list *subsys;
+
+	if (subsys_id >= SKB_DROP_REASON_SUBSYS_NUM)
+		return NULL;
+
+	subsys = rcu_dereference(drop_reasons_by_subsys[subsys_id]);
+	if (!subsys)
+		return NULL;
+	if (reason >= subsys->n_reasons)
+		return NULL;
+	return subsys->reasons[reason];
+}
+
+void drop_reason_show(struct seq_file *m)
+{
+	u32 subsys_id;
+
+	rcu_read_lock();
+	for (subsys_id = 0; subsys_id < SKB_DROP_REASON_SUBSYS_NUM; subsys_id++) {
+		const struct drop_reason_list *subsys;
+		u32 i;
+
+		subsys = rcu_dereference(drop_reasons_by_subsys[subsys_id]);
+		if (!subsys)
+			continue;
+
+		for (i = 0; i < subsys->n_reasons; i++) {
+			if (!subsys->reasons[i])
+				continue;
+			seq_printf(m, ", { %u, \"%s\" }",
+				   (subsys_id << SKB_DROP_REASON_SUBSYS_SHIFT) | i,
+				   subsys->reasons[i]);
+		}
+	}
+	rcu_read_unlock();
+}
+#endif
+
 /**
  * drop_reasons_register_subsys - register another drop reason subsystem
  * @subsys: the subsystem to register, must not be the core

@@ -234,7 +234,7 @@ ovs_drop_reason_count()
 	local reason=$1
 
 	local perf_output=`perf script -i ${ovs_dir}/perf.data -F trace:event,trace`
-	local pattern="skb:kfree_skb:.*reason: $reason"
+	local pattern="skb:kfree_skb:.*reason: $reason$"
 
 	return `echo "$perf_output" | grep "$pattern" | wc -l`
 }

@@ -790,15 +790,6 @@ test_psample() {
 # - drop packets and verify the right drop reason is reported
 test_drop_reason() {
 	which perf >/dev/null 2>&1 || return $ksft_skip
-	which pahole >/dev/null 2>&1 || return $ksft_skip
-
-	ovs_drop_subsys=$(pahole -C skb_drop_reason_subsys |
-			      awk '/OPENVSWITCH/ { print $3; }' |
-			      tr -d ,)
-	if [ -z "$ovs_drop_subsys" ]; then
-		info "failed to get OVS drop subsys ID"
-		return $ksft_skip
-	fi
 
 	sbx_add "test_drop_reason" || return $?
 

@@ -842,7 +833,7 @@ test_drop_reason() {
 		"in_port(2),eth(),eth_type(0x0800),ipv4(src=172.31.110.20,proto=1),icmp()" 'drop'
 
 	ovs_drop_record_and_run "test_drop_reason" ip netns exec client ping -c 2 172.31.110.20
-	ovs_drop_reason_count 0x${ovs_drop_subsys}0001 # OVS_DROP_FLOW_ACTION
+	ovs_drop_reason_count OVS_DROP_LAST_ACTION
 	if [[ "$?" -ne "2" ]]; then
 		info "Did not detect expected drops: $?"
 		return 1

@@ -859,7 +850,7 @@ test_drop_reason() {
 
 	ovs_drop_record_and_run \
             "test_drop_reason" ip netns exec client nc -i 1 -zuv 172.31.110.20 6000
-	ovs_drop_reason_count 0x${ovs_drop_subsys}0004 # OVS_DROP_EXPLICIT_ACTION_ERROR
+	ovs_drop_reason_count OVS_DROP_EXPLICIT_WITH_ERROR
 	if [[ "$?" -ne "1" ]]; then
 		info "Did not detect expected explicit error drops: $?"
 		return 1

@@ -867,7 +858,7 @@ test_drop_reason() {
 
 	ovs_drop_record_and_run \
             "test_drop_reason" ip netns exec client nc -i 1 -zuv 172.31.110.20 7000
-	ovs_drop_reason_count 0x${ovs_drop_subsys}0003 # OVS_DROP_EXPLICIT_ACTION
+	ovs_drop_reason_count OVS_DROP_EXPLICIT
 	if [[ "$?" -ne "1" ]]; then
 		info "Did not detect expected explicit drops: $?"
 		return 1