return -EINVAL;
if (!num_subbuf || (num_subbuf & (num_subbuf - 1)))
return -EINVAL;
+ /*
+ * Overwrite mode buffers require at least 2 subbuffers per
+ * buffer.
+ */
+ if (config->mode == RING_BUFFER_OVERWRITE && num_subbuf < 2)
+ return -EINVAL;
ret = subbuffer_id_check_index(config, num_subbuf);
if (ret)
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));
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));
* @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)
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;
*
* Return the address where a given offset is located (for read).
* Should be used to get the current subbuffer header pointer. Given we know
- * it's never on a page boundary, it's safe to write directly to this address,
- * as long as the write is never bigger than a page size.
+ * it's never on a page boundary, it's safe to read/write directly
+ * from/to this address, as long as the read/write is never bigger than
+ * a page size.
*/
void *lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb,
size_t offset,