set the IP in return probes to the returned-to instruction

It's easily available in kretprobes and uretprobes and is consistent
with the rest of the program state.

* translate.cxx (emit_common_header) : add uretprobe_instance to context.
* tapsets.cxx (common_probe_entryfn_prologue): Initialize ri in
  context to 0.
  (dwarf_derived_probe_group::emit_module_decls): Change IP to return
  address in kretprobes.
  (uprobe_derived_probe_group::emit_module_decls): enter_uretprobe_probe:
  set ri (uretprobe_instance) in context. Change IP to return
  address in uretprobes. Don't emit uprobe include and #define
* runtime/runtime.h : Add includes and #define for uprobes.
* runtime/stack.c (_stp_stack_print, _stp_stack_snprint): Add extra
  argument for uretprobe_instance.
* tapset/context-unwind.stp (print_backtrace, backtrace): Pass NULL
  for uretprobe_instance to _stp_stack_print.
* tapset/ucontext-unwind.stp (print_ubacktrace, ubacktrace): pass
  uretprobe_instance to _stp_stack_print
* testsuite/systemtap.context/uprobe_uaddr.exp : new test for uaddr in
  function probes
* testsuite/systemtap.context/uprobe_uaddr.stp : new file

1 files changed, 1 insertions, 0 deletions

diff --git a/translate.cxx b/translate.cxx
index aca0d868..e6c8cde9 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -905,6 +905,7 @@ c_unparser::emit_common_header ()
   o->newline() << "cycles_t cycles_base;";
   o->newline() << "cycles_t cycles_sum;";
   o->newline() << "#endif";
+  o->newline() << "struct uretprobe_instance *ri;";
 
 
   // PR10516: probe locals