stats: fix memory leakage when adding / deleting interfaces

This fixes two leaks in registering errors in the stats segment.
- The error name created by vlib_register_errors() was not freed.
- Duplicate error names (when interface readded) was added to the vector.

This fix also adds memory usage statistics for the statistics segment
as /mem/statseg/{used, total}

Change-Id: Ife98d5fc5baef5bdae426a5a1eef428af2b9ab8a
Type: fix
Signed-off-by: Ole Troan <ot@cisco.com>

7 files changed, 94 insertions, 21 deletions

diff --git a/src/vlib/error.c b/src/vlib/error.c
index 7c61f319fc0..ef506635ad9 100644
--- a/src/vlib/error.c
+++ b/src/vlib/error.c
@@ -166,7 +166,7 @@ vlib_register_errors (vlib_main_t * vm,
       {
 	error_name = format (0, "/err/%v/%s%c", n->name, error_strings[i], 0);
 	/* Note: error_name consumed by the following call */
-	vlib_stats_register_error_index (error_name, em->counters,
+	vlib_stats_register_error_index (oldheap, error_name, em->counters,
 					 n->error_heap_index + i);
       }
   }
diff --git a/src/vlib/stat_weak_inlines.h b/src/vlib/stat_weak_inlines.h
index 5c04610ef13..d288a04c477 100644
--- a/src/vlib/stat_weak_inlines.h
+++ b/src/vlib/stat_weak_inlines.h
@@ -32,10 +32,10 @@ void
 vlib_stats_pop_heap (void *notused, void *notused2, u32 i, int type)
 {
 };
-void vlib_stats_register_error_index (u8 *, u64 *, u64)
+void vlib_stats_register_error_index (void *, u8 *, u64 *, u64)
   __attribute__ ((weak));
 void
-vlib_stats_register_error_index (u8 * notused, u64 * notused2, u64 notused3)
+vlib_stats_register_error_index (void * notused, u8 * notused2, u64 * notused3, u64 notused4)
 {
 };
 
diff --git a/src/vpp/stats/stat_segment.c b/src/vpp/stats/stat_segment.c
index cef792fc622..c3521cf3dcf 100644
--- a/src/vpp/stats/stat_segment.c
+++ b/src/vpp/stats/stat_segment.c
@@ -22,6 +22,7 @@
 #undef HAVE_MEMFD_CREATE
 #include <vppinfra/linux/syscall.h>
 #include <vpp-api/client/stat_client.h>
+#include <vppinfra/mheap.h>
 
 stat_segment_main_t stat_segment_main;
 
@@ -58,14 +59,16 @@ vlib_stats_push_heap (void *old)
   return clib_mem_set_heap (sm->heap);
 }
 
-/* Name to vector index hash */
 static u32
-lookup_or_create_hash_index (void *oldheap, char *name, u32 next_vector_index)
+lookup_or_create_hash_index (u8 * name, u32 next_vector_index)
 {
   stat_segment_main_t *sm = &stat_segment_main;
   u32 index;
   hash_pair_t *hp;
 
+  /* Must be called in the context of the main heap */
+  ASSERT (clib_mem_get_heap != sm->heap);
+
   hp = hash_get_pair (sm->directory_vector_by_name, name);
   if (!hp)
     {
@@ -106,7 +109,7 @@ vlib_stats_pop_heap (void *cm_arg, void *oldheap, u32 cindex,
     cm->stat_segment_name ? cm->stat_segment_name : cm->name;
   u32 next_vector_index = vec_len (sm->directory_vector);
   clib_mem_set_heap (oldheap);	/* Exit stats segment */
-  u32 vector_index = lookup_or_create_hash_index (oldheap, stat_segment_name,
+  u32 vector_index = lookup_or_create_hash_index ((u8 *) stat_segment_name,
 						  next_vector_index);
   /* Back to stats segment */
   clib_mem_set_heap (sm->heap);	/* Re-enter stat segment */
@@ -153,7 +156,8 @@ vlib_stats_pop_heap (void *cm_arg, void *oldheap, u32 cindex,
 }
 
 void
-vlib_stats_register_error_index (u8 * name, u64 * em_vec, u64 index)
+vlib_stats_register_error_index (void *oldheap, u8 * name, u64 * em_vec,
+				 u64 index)
 {
   stat_segment_main_t *sm = &stat_segment_main;
   stat_segment_shared_header_t *shared_header = sm->shared_header;
@@ -162,17 +166,32 @@ vlib_stats_register_error_index (u8 * name, u64 * em_vec, u64 index)
   ASSERT (shared_header);
 
   vlib_stat_segment_lock ();
+  u32 next_vector_index = vec_len (sm->directory_vector);
+  clib_mem_set_heap (oldheap);	/* Exit stats segment */
 
-  memcpy (e.name, name, vec_len (name));
-  e.name[vec_len (name)] = '\0';
-  e.type = STAT_DIR_TYPE_ERROR_INDEX;
-  e.offset = index;
-  e.offset_vector = 0;
-  vec_add1 (sm->directory_vector, e);
+  u32 vector_index = lookup_or_create_hash_index (name,
+						  next_vector_index);
 
-  /* Warn clients to refresh any pointers they might be holding */
-  shared_header->directory_offset =
-    stat_segment_offset (shared_header, sm->directory_vector);
+  /* Back to stats segment */
+  clib_mem_set_heap (sm->heap);	/* Re-enter stat segment */
+
+  if (next_vector_index == vector_index)
+    {
+      memcpy (e.name, name, vec_len (name));
+      e.name[vec_len (name)] = '\0';
+      e.type = STAT_DIR_TYPE_ERROR_INDEX;
+      e.offset = index;
+      e.offset_vector = 0;
+      vec_add1 (sm->directory_vector, e);
+
+      /* Warn clients to refresh any pointers they might be holding */
+      shared_header->directory_offset =
+	stat_segment_offset (shared_header, sm->directory_vector);
+    }
+  else
+    {
+      vec_free (name);
+    }
 
   vlib_stat_segment_unlock ();
 }
@@ -298,6 +317,12 @@ vlib_map_stat_segment_init (void)
 
   clib_mem_set_heap (oldheap);
 
+  /* Total shared memory size */
+  clib_mem_usage_t usage;
+  mheap_usage (sm->heap, &usage);
+  sm->directory_vector[STAT_COUNTER_MEM_STATSEG_TOTAL].value =
+    usage.bytes_total;
+
   return 0;
 }
 
@@ -581,6 +606,12 @@ do_stat_segment_updates (stat_segment_main_t * sm)
   sm->directory_vector[STAT_COUNTER_LAST_STATS_CLEAR].value =
     vm->node_main.time_last_runtime_stats_clear;
 
+  /* Stats segment memory heap counter */
+  clib_mem_usage_t usage;
+  mheap_usage (sm->heap, &usage);
+  sm->directory_vector[STAT_COUNTER_MEM_STATSEG_USED].value =
+    usage.bytes_used;
+
   if (sm->node_counters_enabled)
     update_node_counters (sm);
 
@@ -707,11 +738,17 @@ stat_segment_register_gauge (u8 * name, stat_segment_update_fn update_fn,
   stat_segment_shared_header_t *shared_header = sm->shared_header;
   void *oldheap;
   stat_segment_directory_entry_t e;
-  u32 index;
   stat_segment_gauges_pool_t *gauge;
 
   ASSERT (shared_header);
 
+  u32 next_vector_index = vec_len (sm->directory_vector);
+  u32 vector_index = lookup_or_create_hash_index (name,
+						  next_vector_index);
+
+  if (vector_index < next_vector_index)	/* Already registered */
+    return clib_error_return (0, "%v is alreadty registered", name);
+
   oldheap = vlib_stats_push_heap (NULL);
   vlib_stat_segment_lock ();
 
@@ -719,7 +756,6 @@ stat_segment_register_gauge (u8 * name, stat_segment_update_fn update_fn,
   e.type = STAT_DIR_TYPE_SCALAR_INDEX;
 
   memcpy (e.name, name, vec_len (name));
-  index = vec_len (sm->directory_vector);
   vec_add1 (sm->directory_vector, e);
 
   shared_header->directory_offset =
@@ -732,7 +768,7 @@ stat_segment_register_gauge (u8 * name, stat_segment_update_fn update_fn,
   pool_get (sm->gauges, gauge);
   gauge->fn = update_fn;
   gauge->caller_index = caller_index;
-  gauge->directory_index = index;
+  gauge->directory_index = next_vector_index;
 
   return NULL;
 }
diff --git a/src/vpp/stats/stat_segment.h b/src/vpp/stats/stat_segment.h
index 113eb9a25ad..a67c59feed5 100644
--- a/src/vpp/stats/stat_segment.h
+++ b/src/vpp/stats/stat_segment.h
@@ -36,6 +36,8 @@ typedef enum
  STAT_COUNTER_NODE_SUSPENDS,
  STAT_COUNTER_INTERFACE_NAMES,
  STAT_COUNTER_NODE_NAMES,
+ STAT_COUNTER_MEM_STATSEG_TOTAL,
+ STAT_COUNTER_MEM_STATSEG_USED,
  STAT_COUNTERS
 } stat_segment_counter_t;
 
@@ -53,7 +55,9 @@ typedef enum
   _(NODE_CALLS, COUNTER_VECTOR_SIMPLE, calls, /sys/node)        \
   _(NODE_SUSPENDS, COUNTER_VECTOR_SIMPLE, suspends, /sys/node)  \
   _(INTERFACE_NAMES, NAME_VECTOR, names, /if)                   \
-  _(NODE_NAMES, NAME_VECTOR, names, /sys/node)
+  _(NODE_NAMES, NAME_VECTOR, names, /sys/node)                  \
+  _(MEM_STATSEG_TOTAL, SCALAR_INDEX, total, /mem/statseg)       \
+  _(MEM_STATSEG_USED, SCALAR_INDEX, used, /mem/statseg)
 
 typedef struct
 {
diff --git a/src/vppinfra/mem_dlmalloc.c b/src/vppinfra/mem_dlmalloc.c
index 99f1c04f3eb..7a53a8bb43b 100644
--- a/src/vppinfra/mem_dlmalloc.c
+++ b/src/vppinfra/mem_dlmalloc.c
@@ -383,6 +383,21 @@ clib_mem_usage (clib_mem_usage_t * u)
   clib_warning ("unimp");
 }
 
+void
+mheap_usage (void *heap, clib_mem_usage_t * usage)
+{
+  struct dlmallinfo mi = mspace_mallinfo (heap);
+
+  /* TODO: Fill in some more values */
+  usage->object_count = 0;
+  usage->bytes_total = mi.arena;
+  usage->bytes_overhead = 0;
+  usage->bytes_max = 0;
+  usage->bytes_used = mi.uordblks;
+  usage->bytes_free = mi.fordblks;
+  usage->bytes_free_reclaimed = 0;
+}
+
 /* Call serial number for debugger breakpoints. */
 uword clib_mem_validate_serial = 0;
 
diff --git a/src/vppinfra/mheap.h b/src/vppinfra/mheap.h
index afc2bf485b5..61d262c5f33 100644
--- a/src/vppinfra/mheap.h
+++ b/src/vppinfra/mheap.h
@@ -90,6 +90,7 @@ int test_mheap_main (unformat_input_t * input);
 /* Format mheap data structures as string. */
 u8 *format_mheap (u8 * s, va_list * va);
 void *mheap_alloc_with_lock (void *memory, uword size, int locked);
+void mheap_usage (void *v, clib_mem_usage_t * usage);
 
 #endif /* USE_DLMALLOC */
 
diff --git a/test/test_stats_client.py b/test/test_stats_client.py
index a0504fc45ab..672a77a0e0a 100644
--- a/test/test_stats_client.py
+++ b/test/test_stats_client.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python2.7
 
 import unittest
-
+import time
 import psutil
 from vpp_papi.vpp_stats import VPPStats
 
@@ -42,6 +42,23 @@ class StatsClientTestCase(VppTestCase):
                          "is not equal to "
                          "ending client side file descriptor count: %s" % (
                              initial_fds, ending_fds))
+    @unittest.skip("Manual only")
+    def test_mem_leak(self):
+        def loop():
+            print('Running loop')
+            for i in range(50):
+                rv = self.vapi.papi.tap_create_v2(id=i, use_random_mac=1)
+                self.assertEqual(rv.retval, 0)
+                rv = self.vapi.papi.tap_delete_v2(sw_if_index=rv.sw_if_index)
+                self.assertEqual(rv.retval, 0)
+
+        before = self.statistics.get_counter('/mem/statseg/used')
+        loop()
+        self.vapi.cli("memory-trace on stats-segment")
+        for j in range(100):
+            loop()
+        print(self.vapi.cli("show memory stats-segment verbose"))
+        print('AFTER', before, self.statistics.get_counter('/mem/statseg/used'))
 
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)