- /*
- * It is possible to have multiple instances associated with a given
- * task either because multiple functions in the call path have
- * return probes installed on them, and/or more than one
- * return probe was registered for a target function.
- *
- * We can handle this because:
- * - instances are always pushed into the head of the list
- * - when multiple return probes are registered for the same
- * function, the (chronologically) first instance's ret_addr
- * will be the real return address, and all the rest will
- * point to kretprobe_trampoline.
- */
- hlist_for_each_entry(ri, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
- /*
- * Return probes must be pushed on this hash list correct
- * order (same as return order) so that it can be popped
- * correctly. However, if we find it is pushed it incorrect
- * order, this means we find a function which should not be
- * probed, because the wrong order entry is pushed on the
- * path of processing other kretprobe itself.
- */
- if (ri->fp != frame_pointer) {
- if (!skipped)
- pr_warn("kretprobe is stacked incorrectly. Trying to fixup.\n");
- skipped = true;
- continue;
- }