api: avoid swapping vlib_rp before barrier sync

Type: fix

Change-Id: I9868d13e827c6f5aa5535a38f629efb62ff12dbc
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
Signed-off-by: Florin Coras <fcoras@cisco.com>

src/vlibapi/api.h

@@ -105,9 +105,10 @@ int vl_msg_api_trace_onoff (api_main_t * am, vl_api_trace_which_t which,
 int vl_msg_api_trace_free (api_main_t * am, vl_api_trace_which_t which);
 int vl_msg_api_trace_configure (api_main_t * am, vl_api_trace_which_t which,
 				u32 nitems);
-void vl_msg_api_handler_with_vm_node (api_main_t * am,
+void vl_msg_api_handler_with_vm_node (api_main_t * am, svm_region_t * vlib_rp,
 				      void *the_msg, vlib_main_t * vm,
-				      vlib_node_runtime_t * node);
+				      vlib_node_runtime_t * node,
+				      u8 is_private);
 vl_api_trace_t *vl_msg_api_trace_get (api_main_t * am,
 				      vl_api_trace_which_t which);
 void vl_msg_api_add_msg_name_crc (api_main_t * am, const char *string,

src/vlibapi/api_shared.c

@@ -525,13 +525,15 @@ msg_handler_internal (api_main_t * am,
 
 /* This is only to be called from a vlib/vnet app */
 void
-vl_msg_api_handler_with_vm_node (api_main_t * am,
+vl_msg_api_handler_with_vm_node (api_main_t * am, svm_region_t * vlib_rp,
 				 void *the_msg, vlib_main_t * vm,
-				 vlib_node_runtime_t * node)
+				 vlib_node_runtime_t * node, u8 is_private)
 {
   u16 id = clib_net_to_host_u16 (*((u16 *) the_msg));
   u8 *(*handler) (void *, void *, void *);
   u8 *(*print_fp) (void *, void *);
+  svm_region_t *old_vlib_rp;
+  void *save_shmem_hdr;
   int is_mp_safe = 1;
 
   if (PREDICT_FALSE (am->elog_trace_api_messages))
@@ -581,7 +583,19 @@ vl_msg_api_handler_with_vm_node (api_main_t * am,
 	  vl_msg_api_barrier_trace_context (am->msg_names[id]);
 	  vl_msg_api_barrier_sync ();
 	}
+      if (is_private)
+	{
+	  old_vlib_rp = am->vlib_rp;
+	  save_shmem_hdr = am->shmem_hdr;
+	  am->vlib_rp = vlib_rp;
+	  am->shmem_hdr = (void *) vlib_rp->user_ctx;
+	}
       (*handler) (the_msg, vm, node);
+      if (is_private)
+	{
+	  am->vlib_rp = old_vlib_rp;
+	  am->shmem_hdr = save_shmem_hdr;
+	}
       if (!is_mp_safe)
 	vl_msg_api_barrier_release ();
     }

src/vlibmemory/memory_api.c

@@ -503,10 +503,8 @@ static void
 send_memclnt_keepalive (vl_api_registration_t * regp, f64 now)
 {
   vl_api_memclnt_keepalive_t *mp;
-  svm_queue_t *q;
   api_main_t *am = &api_main;
-  svm_region_t *save_vlib_rp = am->vlib_rp;
+  svm_queue_t *q;
-  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;
 
   q = regp->vl_input_queue;
 
@@ -530,10 +528,7 @@ send_memclnt_keepalive (vl_api_registration_t * regp, f64 now)
    * memory clients..
    */
 
-  am->vlib_rp = regp->vlib_rp;
+  mp = vl_mem_api_alloc_as_if_client_w_reg (regp, sizeof (*mp));
-  am->shmem_hdr = regp->shmem_hdr;
-
-  mp = vl_msg_api_alloc (sizeof (*mp));
   clib_memset (mp, 0, sizeof (*mp));
   mp->_vl_msg_id = clib_host_to_net_u16 (VL_API_MEMCLNT_KEEPALIVE);
   mp->context = mp->client_index =
@@ -545,10 +540,7 @@ send_memclnt_keepalive (vl_api_registration_t * regp, f64 now)
 
   /* Failure-to-send due to a stuffed queue is absolutely expected */
   if (svm_queue_add (q, (u8 *) & mp, 1 /* nowait */ ))
-    vl_msg_api_free (mp);
+    vl_msg_api_free_w_region (regp->vlib_rp, mp);
-
-  am->vlib_rp = save_vlib_rp;
-  am->shmem_hdr = save_shmem_hdr;
 }
 
 static void
@@ -708,14 +700,20 @@ vl_mem_api_dead_client_scan (api_main_t * am, vl_shmem_hdr_t * shm, f64 now)
 }
 
 static inline int
-void_mem_api_handle_msg_i (api_main_t * am, vlib_main_t * vm,
+void_mem_api_handle_msg_i (api_main_t * am, svm_region_t * vlib_rp,
-			   vlib_node_runtime_t * node, svm_queue_t * q)
+			   vlib_main_t * vm, vlib_node_runtime_t * node,
+			   u8 is_private)
 {
+  svm_queue_t *q;
   uword mp;
+
+  q = ((vl_shmem_hdr_t *) (void *) vlib_rp->user_ctx)->vl_input_queue;
+
   if (!svm_queue_sub2 (q, (u8 *) & mp))
     {
       VL_MSG_API_UNPOISON ((void *) mp);
-      vl_msg_api_handler_with_vm_node (am, (void *) mp, vm, node);
+      vl_msg_api_handler_with_vm_node (am, vlib_rp, (void *) mp, vm, node,
+				       is_private);
       return 0;
     }
   return -1;
@@ -725,8 +723,8 @@ int
 vl_mem_api_handle_msg_main (vlib_main_t * vm, vlib_node_runtime_t * node)
 {
   api_main_t *am = &api_main;
-  return void_mem_api_handle_msg_i (am, vm, node,
+  return void_mem_api_handle_msg_i (am, am->vlib_rp, vm, node,
-				    am->shmem_hdr->vl_input_queue);
+				    0 /* is_private */ );
 }
 
 int
@@ -764,7 +762,8 @@ vl_mem_api_handle_rpc (vlib_main_t * vm, vlib_node_runtime_t * node)
       for (i = 0; i < vec_len (vm->processing_rpc_requests); i++)
 	{
 	  mp = vm->processing_rpc_requests[i];
-	  vl_msg_api_handler_with_vm_node (am, (void *) mp, vm, node);
+	  vl_msg_api_handler_with_vm_node (am, am->vlib_rp, (void *) mp, vm,
+					   node, 0 /* is_private */ );
 	}
       vl_msg_api_barrier_release ();
     }
@@ -777,22 +776,9 @@ vl_mem_api_handle_msg_private (vlib_main_t * vm, vlib_node_runtime_t * node,
 			       u32 reg_index)
 {
   api_main_t *am = &api_main;
-  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;
-  svm_region_t *vlib_rp, *save_vlib_rp = am->vlib_rp;
-  svm_queue_t *q;
-  int rv;
 
-  vlib_rp = am->vlib_rp = am->vlib_private_rps[reg_index];
+  return void_mem_api_handle_msg_i (am, am->vlib_private_rps[reg_index], vm,
-
+				    node, 1 /* is_private */ );
-  am->shmem_hdr = (void *) vlib_rp->user_ctx;
-  q = am->shmem_hdr->vl_input_queue;
-
-  rv = void_mem_api_handle_msg_i (am, vm, node, q);
-
-  am->shmem_hdr = save_shmem_hdr;
-  am->vlib_rp = save_vlib_rp;
-
-  return rv;
 }
 
 vl_api_registration_t *

src/vlibmemory/memory_shared.c

@@ -43,7 +43,8 @@
 #define DEBUG_MESSAGE_BUFFER_OVERRUN 0
 
 CLIB_NOSANITIZE_ADDR static inline void *
-vl_msg_api_alloc_internal (int nbytes, int pool, int may_return_null)
+vl_msg_api_alloc_internal (svm_region_t * vlib_rp, int nbytes, int pool,
+			   int may_return_null)
 {
   int i;
   msgbuf_t *rv;
@@ -53,7 +54,7 @@ vl_msg_api_alloc_internal (int nbytes, int pool, int may_return_null)
   vl_shmem_hdr_t *shmem_hdr;
   api_main_t *am = &api_main;
 
-  shmem_hdr = am->shmem_hdr;
+  shmem_hdr = (void *) vlib_rp->user_ctx;
 
 #if DEBUG_MESSAGE_BUFFER_OVERRUN > 0
   nbytes += 4;
@@ -161,15 +162,15 @@ vl_msg_api_alloc_internal (int nbytes, int pool, int may_return_null)
    */
   am->ring_misses++;
 
-  pthread_mutex_lock (&am->vlib_rp->mutex);
+  pthread_mutex_lock (&vlib_rp->mutex);
-  oldheap = svm_push_data_heap (am->vlib_rp);
+  oldheap = svm_push_data_heap (vlib_rp);
   if (may_return_null)
     {
       rv = clib_mem_alloc_or_null (nbytes);
       if (PREDICT_FALSE (rv == 0))
 	{
 	  svm_pop_heap (oldheap);
-	  pthread_mutex_unlock (&am->vlib_rp->mutex);
+	  pthread_mutex_unlock (&vlib_rp->mutex);
 	  return 0;
 	}
     }
@@ -179,7 +180,7 @@ vl_msg_api_alloc_internal (int nbytes, int pool, int may_return_null)
   rv->q = 0;
   rv->gc_mark_timestamp = 0;
   svm_pop_heap (oldheap);
-  pthread_mutex_unlock (&am->vlib_rp->mutex);
+  pthread_mutex_unlock (&vlib_rp->mutex);
 
 out:
 #if DEBUG_MESSAGE_BUFFER_OVERRUN > 0
@@ -207,7 +208,8 @@ vl_msg_api_alloc (int nbytes)
    * Clients use pool-0, vlib proc uses pool 1
    */
   pool = (am->our_pid == shmem_hdr->vl_pid);
-  return vl_msg_api_alloc_internal (nbytes, pool, 0 /* may_return_null */ );
+  return vl_msg_api_alloc_internal (am->vlib_rp, nbytes, pool,
+				    0 /* may_return_null */ );
 }
 
 void *
@@ -228,13 +230,15 @@ vl_msg_api_alloc_or_null (int nbytes)
   vl_shmem_hdr_t *shmem_hdr = am->shmem_hdr;
 
   pool = (am->our_pid == shmem_hdr->vl_pid);
-  return vl_msg_api_alloc_internal (nbytes, pool, 1 /* may_return_null */ );
+  return vl_msg_api_alloc_internal (am->vlib_rp, nbytes, pool,
+				    1 /* may_return_null */ );
 }
 
 void *
 vl_msg_api_alloc_as_if_client (int nbytes)
 {
-  return vl_msg_api_alloc_internal (nbytes, 0, 0 /* may_return_null */ );
+  return vl_msg_api_alloc_internal (api_main.vlib_rp, nbytes, 0,
+				    0 /* may_return_null */ );
 }
 
 void *
@@ -250,34 +254,22 @@ vl_msg_api_alloc_zero_as_if_client (int nbytes)
 void *
 vl_msg_api_alloc_as_if_client_or_null (int nbytes)
 {
-  return vl_msg_api_alloc_internal (nbytes, 0, 1 /* may_return_null */ );
+  return vl_msg_api_alloc_internal (api_main.vlib_rp, nbytes, 0,
+				    1 /* may_return_null */ );
 }
 
 void *
 vl_mem_api_alloc_as_if_client_w_reg (vl_api_registration_t * reg, int nbytes)
 {
-  api_main_t *am = &api_main;
+  return vl_msg_api_alloc_internal (reg->vlib_rp, nbytes, 0,
-  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;
+				    0 /* may_return_null */ );
-  svm_region_t *vlib_rp, *save_vlib_rp = am->vlib_rp;
-  void *msg;
-
-  vlib_rp = am->vlib_rp = reg->vlib_rp;
-  am->shmem_hdr = (void *) vlib_rp->user_ctx;
-
-  msg = vl_msg_api_alloc_internal (nbytes, 0, 0 /* may_return_null */ );
-
-  am->shmem_hdr = save_shmem_hdr;
-  am->vlib_rp = save_vlib_rp;
-
-  return msg;
 }
 
 void
-vl_msg_api_free (void *a)
+vl_msg_api_free_w_region (svm_region_t * vlib_rp, void *a)
 {
   msgbuf_t *rv;
   void *oldheap;
-  api_main_t *am = &api_main;
 
   rv = (msgbuf_t *) (((u8 *) a) - offsetof (msgbuf_t, data));
 
@@ -301,8 +293,8 @@ vl_msg_api_free (void *a)
       return;
     }
 
-  pthread_mutex_lock (&am->vlib_rp->mutex);
+  pthread_mutex_lock (&vlib_rp->mutex);
-  oldheap = svm_push_data_heap (am->vlib_rp);
+  oldheap = svm_push_data_heap (vlib_rp);
 
 #if DEBUG_MESSAGE_BUFFER_OVERRUN > 0
   {
@@ -314,7 +306,13 @@ vl_msg_api_free (void *a)
 
   clib_mem_free (rv);
   svm_pop_heap (oldheap);
-  pthread_mutex_unlock (&am->vlib_rp->mutex);
+  pthread_mutex_unlock (&vlib_rp->mutex);
+}
+
+void
+vl_msg_api_free (void *a)
+{
+  vl_msg_api_free_w_region (api_main.vlib_rp, a);
 }
 
 static void

src/vlibmemory/memory_shared.h

@@ -117,6 +117,7 @@ void *vl_msg_api_alloc_as_if_client_or_null (int nbytes);
 void *vl_mem_api_alloc_as_if_client_w_reg (vl_api_registration_t * reg,
 					   int nbytes);
 void vl_msg_api_free (void *a);
+void vl_msg_api_free_w_region (svm_region_t * vlib_rp, void *a);
 int vl_map_shmem (const char *region_name, int is_vlib);
 void vl_unmap_shmem (void);
 void vl_unmap_shmem_client (void);