* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
*/
static
-int __cpuinit lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
+int lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
unsigned long action,
void *hcpu)
{
* @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 lib_ring_buffer_backend *bufb, size_t offset,
void *dest, size_t len)
offset &= chanb->buf_size - 1;
index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT;
orig_offset = offset;
+ if (unlikely(!len))
+ return -EINVAL;
for (;;) {
id = bufb->buf_rsb.id;
sb_bindex = subbuffer_id_get_index(config, 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 lib_ring_buffer_backend *bufb,
size_t offset)