Fix: clear error counter before adding to lists

[lttng-modules.git] / src / lttng-events.c

diff --git a/src/lttng-events.c b/src/lttng-events.c
index cd8efff18778808404a9a34aa35ba64860a2c17c..981ee30c326cb65be35ff7b6d107d600e09633a4 100644 (file)
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -864,6 +864,48 @@ void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
        wake_up_interruptible(&stream->read_wait);
 }
 
+static
+bool lttng_kernel_event_id_available(struct lttng_event_enabler_common *event_enabler)
+{
+       struct lttng_kernel_abi_event *event_param = &event_enabler->event_param;
+        enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
+
+       switch (event_enabler->enabler_type) {
+       case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
+       {
+               struct lttng_event_recorder_enabler *event_recorder_enabler =
+                       container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
+               struct lttng_kernel_channel_buffer *chan = event_recorder_enabler->chan;
+
+               switch (itype) {
+               case LTTNG_KERNEL_ABI_TRACEPOINT:
+                       lttng_fallthrough;
+               case LTTNG_KERNEL_ABI_KPROBE:
+                       lttng_fallthrough;
+               case LTTNG_KERNEL_ABI_SYSCALL:
+                       lttng_fallthrough;
+               case LTTNG_KERNEL_ABI_UPROBE:
+                       if (chan->priv->free_event_id == -1U)
+                               return false;
+                       return true;
+               case LTTNG_KERNEL_ABI_KRETPROBE:
+                       /* kretprobes require 2 event IDs. */
+                       if (chan->priv->free_event_id >= -2U)
+                               return false;
+                       return true;
+               default:
+                       WARN_ON_ONCE(1);
+                       return false;
+               }
+       }
+       case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
+               return true;
+       default:
+               WARN_ON_ONCE(1);
+               return false;
+       }
+}
+
 static
 struct lttng_kernel_event_common *lttng_kernel_event_alloc(struct lttng_event_enabler_common *event_enabler)
 {
@@ -1025,7 +1067,6 @@ struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct l
 {
        struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_enabler->parent);
        struct list_head *event_list_head = lttng_get_event_list_head_from_enabler(&event_enabler->parent);
-       struct lttng_kernel_channel_buffer *chan = event_enabler->chan;
        struct lttng_kernel_abi_event *event_param = &event_enabler->parent.event_param;
        enum lttng_kernel_abi_instrumentation itype = event_param->instrumentation;
        struct lttng_kernel_event_common_private *event_priv;
@@ -1035,7 +1076,7 @@ struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct l
        struct hlist_head *head;
        int ret;
 
-       if (chan->priv->free_event_id == -1U) {
+       if (!lttng_kernel_event_id_available(&event_enabler->parent)) {
                ret = -EMFILE;
                goto full;
        }
@@ -1122,7 +1163,6 @@ struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct l
        case LTTNG_KERNEL_ABI_KRETPROBE:
        {
                struct lttng_kernel_event_common *event_return;
-               struct lttng_kernel_event_recorder *event_recorder_return;
 
                /* kretprobe defines 2 events */
                /*
@@ -1137,7 +1177,6 @@ struct lttng_kernel_event_recorder *_lttng_kernel_event_recorder_create(struct l
                        ret = -ENOMEM;
                        goto alloc_error;
                }
-               event_recorder_return = container_of(event_return, struct lttng_kernel_event_recorder, parent);
 
                event_return->enabled = 0;
                event_return->priv->registered = 1;
@@ -1427,12 +1466,13 @@ struct lttng_kernel_event_notifier *_lttng_kernel_event_notifier_create(struct l
                goto register_error;
        }
 
-       list_add(&event->priv->node, event_list_head);
-       hlist_add_head(&event->priv->hlist_node, head);
-
        ret = lttng_kernel_event_notifier_clear_error_counter(event);
        if (ret)
                goto register_error;
+
+       list_add(&event->priv->node, event_list_head);
+       hlist_add_head(&event->priv->hlist_node, head);
+
        return event_notifier;
 
 register_error: