From 5e562a69a5432566c6ae78344ae51b80ced7f15b Mon Sep 17 00:00:00 2001
From: Tim Moore <timoore@redhat.com>
Date: Wed, 16 Dec 2009 12:00:55 +0100
Subject: 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
---
 tapsets.cxx | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

(limited to 'tapsets.cxx')

diff --git a/tapsets.cxx b/tapsets.cxx
index cf6f97ef..5729757b 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -142,6 +142,7 @@ common_probe_entryfn_prologue (translator_output* o, string statestr,
   o->newline() << "#ifdef STP_TIMING";
   o->newline() << "c->statp = 0;";
   o->newline() << "#endif";
+  o->newline() << "c->ri = 0;";
   // NB: The following would actually be incorrect.
   // That's because cycles_sum/cycles_base values are supposed to survive
   // between consecutive probes.  Periodically (STP_OVERLOAD_INTERVAL
@@ -3373,8 +3374,15 @@ dwarf_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline() << "{";
   s.op->indent(1);
   s.op->newline() << "unsigned long kprobes_ip = REG_IP(c->regs);";
+  s.op->newline() << "if (entry) {";
+  s.op->indent(1);
   s.op->newline() << "SET_REG_IP(regs, (unsigned long) inst->rp->kp.addr);";
-  s.op->newline() << "(entry ? sdp->entry_ph : sdp->ph) (c);";
+  s.op->newline() << "(sdp->entry_ph) (c);";
+  s.op->newline(-1) << "} else {";
+  s.op->indent(1);
+  s.op->newline() << "SET_REG_IP(regs, (unsigned long)inst->ret_addr);";
+  s.op->newline() << "(sdp->ph) (c);";
+  s.op->newline(-1) << "}";
   s.op->newline() << "SET_REG_IP(regs, kprobes_ip);";
   s.op->newline(-1) << "}";
 
@@ -4569,16 +4577,6 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s)
   if (probes.empty()) return;
   s.op->newline() << "/* ---- user probes ---- */";
 
-  // If uprobes isn't in the kernel, pull it in from the runtime.
-  s.op->newline() << "#if defined(CONFIG_UPROBES) || defined(CONFIG_UPROBES_MODULE)";
-  s.op->newline() << "#include <linux/uprobes.h>";
-  s.op->newline() << "#else";
-  s.op->newline() << "#include \"uprobes/uprobes.h\"";
-  s.op->newline() << "#endif";
-  s.op->newline() << "#ifndef UPROBES_API_VERSION";
-  s.op->newline() << "#define UPROBES_API_VERSION 1";
-  s.op->newline() << "#endif";
-
   // We'll probably need at least this many:
   unsigned minuprobes = probes.size();
   // .. but we don't want so many that .bss is inflated (PR10507):
@@ -4723,6 +4721,7 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline(1) << "struct stap_uprobe *sup = container_of(inst->rp, struct stap_uprobe, urp);";
   s.op->newline() << "const struct stap_uprobe_spec *sups = &stap_uprobe_specs [sup->spec_index];";
   common_probe_entryfn_prologue (s.op, "STAP_SESSION_RUNNING", "sups->pp");
+  s.op->newline() << "c->ri = inst;";
   s.op->newline() << "if (sup->spec_index < 0 ||"
                   << "sup->spec_index >= " << probes.size() << ") return;"; // XXX: should not happen
   // XXX: kretprobes saves "c->pi = inst;" too
@@ -4734,7 +4733,7 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline() << "{";
   s.op->indent(1);
   s.op->newline() << "unsigned long uprobes_ip = REG_IP(c->regs);";
-  s.op->newline() << "SET_REG_IP(regs, inst->rp->u.vaddr);";
+  s.op->newline() << "SET_REG_IP(regs, inst->ret_addr);";
   s.op->newline() << "(*sups->ph) (c);";
   s.op->newline() << "SET_REG_IP(regs, uprobes_ip);";
   s.op->newline(-1) << "}";
-- 
cgit