Fix: ensure kernel context is in a list before trying to delete it

[lttng-tools.git] / src / bin / lttng-sessiond / trace-kernel.c

diff --git a/src/bin/lttng-sessiond/trace-kernel.c b/src/bin/lttng-sessiond/trace-kernel.c
index 876fda5bbb7fd9ed8d25c0cafdd3c348ec466e7c..52b8cc7e0e8d4f2d4e017d746def763f599d9420 100644 (file)
--- a/src/bin/lttng-sessiond/trace-kernel.c
+++ b/src/bin/lttng-sessiond/trace-kernel.c
@@ -181,7 +181,7 @@ struct ltt_kernel_channel *trace_kernel_create_channel(
                struct lttng_channel *chan)
 {
        struct ltt_kernel_channel *lkc;
-       struct lttng_channel_extended *extended;
+       struct lttng_channel_extended *extended = NULL;
 
        assert(chan);
 
@@ -221,6 +221,7 @@ struct ltt_kernel_channel *trace_kernel_create_channel(
        lkc->stream_count = 0;
        lkc->event_count = 0;
        lkc->enabled = 1;
+       lkc->published_to_notification_thread = false;
        /* Init linked list */
        CDS_INIT_LIST_HEAD(&lkc->events_list.head);
        CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
@@ -256,11 +257,33 @@ struct ltt_kernel_context *trace_kernel_create_context(
        if (ctx) {
                memcpy(&kctx->ctx, ctx, sizeof(kctx->ctx));
        }
+error:
+       return kctx;
+}
+
+/*
+ * Allocate and init a kernel context object from an existing kernel context
+ * object.
+ *
+ * Return the allocated object or NULL on error.
+ */
+struct ltt_kernel_context *trace_kernel_copy_context(
+               struct ltt_kernel_context *kctx)
+{
+       struct ltt_kernel_context *kctx_copy;
 
-       CDS_INIT_LIST_HEAD(&kctx->list);
+       assert(kctx);
+       kctx_copy = zmalloc(sizeof(*kctx_copy));
+       if (!kctx_copy) {
+               PERROR("zmalloc ltt_kernel_context");
+               goto error;
+       }
+
+       memcpy(kctx_copy, kctx, sizeof(*kctx_copy));
+       memset(&kctx_copy->list, 0, sizeof(kctx_copy->list));
 
 error:
-       return kctx;
+       return kctx_copy;
 }
 
 /*
@@ -478,7 +501,9 @@ void trace_kernel_destroy_context(struct ltt_kernel_context *ctx)
 {
        assert(ctx);
 
-       cds_list_del(&ctx->list);
+       if (ctx->in_list) {
+               cds_list_del(&ctx->list);
+       }
        free(ctx);
 }
 
@@ -522,7 +547,8 @@ void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
        /* Remove from channel list */
        cds_list_del(&channel->list);
 
-       if (notification_thread_handle) {
+       if (notification_thread_handle
+                       && channel->published_to_notification_thread) {
                status = notification_thread_command_remove_channel(
                                notification_thread_handle,
                                channel->fd, LTTNG_DOMAIN_KERNEL);