X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust-ctl%2Fustctl.c;fp=liblttng-ust-ctl%2Fustctl.c;h=49757ffdf552ac31da68c1960008f0b1c204ee39;hb=ebd4c257bc3ca6b659a90ee6219f5389fb3ab5e5;hp=195f29c03cd211eac3a3fc354e56cd88a574dc4a;hpb=9f8140ba23fd62cad18be0f58193480e6b5aaae6;p=lttng-ust.git

diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
index 195f29c0..49757ffd 100644
--- a/liblttng-ust-ctl/ustctl.c
+++ b/liblttng-ust-ctl/ustctl.c
@@ -1334,6 +1334,8 @@ int ustctl_get_mmap_read_offset(struct ustctl_consumer_stream *stream,
 	unsigned long sb_bindex;
 	struct lttng_ust_lib_ring_buffer *buf;
 	struct ustctl_consumer_channel *consumer_chan;
+	struct lttng_ust_lib_ring_buffer_backend_pages_shmp *barray_idx;
+	struct lttng_ust_lib_ring_buffer_backend_pages *pages;
 
 	if (!stream)
 		return -EINVAL;
@@ -1344,8 +1346,14 @@ int ustctl_get_mmap_read_offset(struct ustctl_consumer_stream *stream,
 		return -EINVAL;
 	sb_bindex = subbuffer_id_get_index(&chan->backend.config,
 					buf->backend.buf_rsb.id);
-	*off = shmp(consumer_chan->chan->handle,
-		shmp_index(consumer_chan->chan->handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
+	barray_idx = shmp_index(consumer_chan->chan->handle, buf->backend.array,
+			sb_bindex);
+	if (!barray_idx)
+		return -EINVAL;
+	pages = shmp(consumer_chan->chan->handle, barray_idx->shmp);
+	if (!pages)
+		return -EINVAL;
+	*off = pages->mmap_offset;
 	return 0;
 }
 
@@ -1511,6 +1519,8 @@ struct lttng_ust_client_lib_ring_buffer_client_cb *get_client_cb(
 	struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
 
 	chan = shmp(handle, buf->backend.chan);
+	if (!chan)
+		return NULL;
 	config = &chan->backend.config;
 	if (!config->cb_ptr)
 		return NULL;