uretprobes: Return probe entry, prepare_uretprobe()
When a uprobe with return probe consumer is hit, prepare_uretprobe()
function is invoked. It creates return_instance, hijacks return address
and replaces it with the trampoline.
* Return instances are kept as stack per uprobed task.
* Return instance is chained, when the original return address is
trampoline's page vaddr (e.g. recursive call of the probed function).
Signed-off-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 5c8d329..b0507f2 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -71,6 +71,7 @@
enum uprobe_task_state state;
struct arch_uprobe_task autask;
+ struct return_instance *return_instances;
struct uprobe *active_uprobe;
unsigned long xol_vaddr;