X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fring_buffer_backend.c;h=3db1f860f3918d8a1e61a959e1f4501678f93687;hb=addc89a2fb7874c55ed5bc8b9b463a62bc1b17ca;hp=ae8365227c3405fcb39aad8a32eba3e5d730be14;hpb=9501d22f55b3a23f382f631c99b2325d1419b5da;p=lttng-ust.git

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index ae836522..3db1f860 100644
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -280,7 +280,8 @@ int channel_backend_init(struct channel_backend *chanb,
 		for_each_possible_cpu(i) {
 			struct shm_object *shmobj;
 
-			shmobj = shm_object_table_append(handle->table, shmsize);
+			shmobj = shm_object_table_alloc(handle->table, shmsize,
+					SHM_OBJECT_SHM);
 			if (!shmobj)
 				goto end;
 			align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -298,7 +299,8 @@ int channel_backend_init(struct channel_backend *chanb,
 		struct shm_object *shmobj;
 		struct lttng_ust_lib_ring_buffer *buf;
 
-		shmobj = shm_object_table_append(handle->table, shmsize);
+		shmobj = shm_object_table_alloc(handle->table, shmsize,
+					SHM_OBJECT_SHM);
 		if (!shmobj)
 			goto end;
 		align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
@@ -379,8 +381,9 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
  * @dest : destination address
  * @len : destination's length
  *
- * return string's length
+ * Return string's length, or -EINVAL on error.
  * Should be protected by get_subbuf/put_subbuf.
+ * Destination length should be at least 1 to hold '\0'.
  */
 int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, size_t offset,
 			      void *dest, size_t len, struct lttng_ust_shm_handle *handle)
@@ -392,6 +395,8 @@ int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, si
 	struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
 	unsigned long sb_bindex, id;
 
+	if (caa_unlikely(!len))
+		return -EINVAL;
 	offset &= chanb->buf_size - 1;
 	orig_offset = offset;
 	id = bufb->buf_rsb.id;