PR10228: use task_finder_vma for -d /user/object files.

* main.cxx (main): For "-d /path" arguments, enable task finder.
* runtime/sym.h (_stp_module): Add *vmcb member.
* task_finder{.cxx,.h} (emit_vma_callback_probe_decl): Zap.
* tapset-itrace.cxx, tapset-utrace.cxx: Use unwindsyms_modules
  instead.
* tapsets.cxx (uprobe::emit_module_decls): Ditto.
* translate.cxx (emit_module_init): Emit task finder registrations
  for vmcb's associated with _stp_modules.
  (dump_unwindsyms): Associate vmcbs with user-space unwindsyms entries.

9 files changed, 46 insertions, 115 deletions

diff --git a/main.cxx b/main.cxx
index daf64561..a3a7e56e 100644
--- a/main.cxx
+++ b/main.cxx
@@ -21,6 +21,8 @@
 #include "coveragedb.h"
 #include "git_version.h"
 #include "rpm_finder.h"
+#include "task_finder.h"
+
 #include "sys/sdt.h"
 
 #include <iostream>
@@ -635,6 +637,9 @@ main (int argc, char * const argv [])
 
         case 'd':
           s.unwindsym_modules.insert (string (optarg));
+          // PR10228: trigger task-finder logic early if -d /USER-MODULE/ given.
+          if (optarg[0] == '/')
+            enable_task_finder (s);
           break;
 
         case 'e':
diff --git a/runtime/sym.c b/runtime/sym.c
index 35fb3cb0..30b6fc5a 100644
--- a/runtime/sym.c
+++ b/runtime/sym.c
@@ -31,8 +31,8 @@ static void _stp_sym_init(void)
 	}
 }
 
-/* Callback that needs to be registered (in tapsets.cxx for
-   emit_module_init) for every user task path or pid for which we
+/* Callback that needs to be registered (in
+   session.unwindsyms_modules) for every user task path for which we
    might need symbols or unwind info. */
 static int _stp_tf_mmap_cb(struct stap_task_finder_target *tgt,
 			   struct task_struct *tsk,
diff --git a/runtime/sym.h b/runtime/sym.h
index ca69345f..262b1776 100644
--- a/runtime/sym.h
+++ b/runtime/sym.h
@@ -30,6 +30,8 @@ struct _stp_module {
 	struct _stp_section *sections;
   	unsigned num_sections;
 
+        struct stap_task_finder_target *vmcb; /* PR10228 */
+
 	/* A pointer to the struct module. Note that we cannot */
 	/* trust this because as of 2.6.19, there are not yet */
 	/* any notifier hooks that will tell us when a module */
diff --git a/tapset-itrace.cxx b/tapset-itrace.cxx
index 87845155..57c20539 100644
--- a/tapset-itrace.cxx
+++ b/tapset-itrace.cxx
@@ -111,7 +111,10 @@ struct itrace_builder: public derived_probe_builder
 
     // If we have a path, we need to validate it.
     if (has_path)
-      path = find_executable (path);
+      {
+        path = find_executable (path);
+        sess.unwindsym_modules.insert (path);
+      }
 
     finished_results.push_back(new itrace_derived_probe(sess, base, location,
 							has_path, path, pid,
@@ -214,25 +217,6 @@ itrace_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline(-1) << "return rc;";
   s.op->newline(-1) << "}";
 
-  // Emit vma callbacks.
-  s.op->newline() << "#ifdef STP_NEED_VMA_TRACKER";
-  s.op->newline() << "static struct stap_task_finder_target stap_itrace_vmcbs[] = {";
-  s.op->indent(1);
-  if (! probes_by_path.empty())
-    {
-      for (p_b_path_iterator it = probes_by_path.begin();
-           it != probes_by_path.end(); it++)
-        emit_vma_callback_probe_decl (s, it->first, (int64_t)0);
-    }
-  if (! probes_by_pid.empty())
-    {
-      for (p_b_pid_iterator it = probes_by_pid.begin();
-           it != probes_by_pid.end(); it++)
-        emit_vma_callback_probe_decl (s, "", it->first);
-    }
-  s.op->newline(-1) << "};";
-  s.op->newline() << "#endif";
-
   s.op->newline() << "static struct stap_itrace_probe stap_itrace_probes[] = {";
   s.op->indent(1);
 
@@ -274,17 +258,6 @@ itrace_derived_probe_group::emit_module_init (systemtap_session& s)
     return;
 
   s.op->newline();
-  s.op->newline() << "#ifdef STP_NEED_VMA_TRACKER";
-  s.op->newline() << "_stp_sym_init();";
-  s.op->newline() << "/* ---- itrace vma callbacks ---- */";
-  s.op->newline() << "for (i=0; i<ARRAY_SIZE(stap_itrace_vmcbs); i++) {";
-  s.op->indent(1);
-  s.op->newline() << "struct stap_task_finder_target *r = &stap_itrace_vmcbs[i];";
-  s.op->newline() << "rc = stap_register_task_finder_target(r);";
-  s.op->newline(-1) << "}";
-  s.op->newline() << "#endif";
-
-  s.op->newline();
   s.op->newline() << "/* ---- itrace probes ---- */";
 
   s.op->newline() << "for (i=0; i<" << num_probes << "; i++) {";
diff --git a/tapset-utrace.cxx b/tapset-utrace.cxx
index a07e08b8..5de62835 100644
--- a/tapset-utrace.cxx
+++ b/tapset-utrace.cxx
@@ -935,25 +935,6 @@ utrace_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline() << "return rc;";
   s.op->newline(-1) << "}";
 
-  // Emit vma callbacks.
-  s.op->newline() << "#ifdef STP_NEED_VMA_TRACKER";
-  s.op->newline() << "static struct stap_task_finder_target stap_utrace_vmcbs[] = {";
-  s.op->indent(1);
-  if (! probes_by_path.empty())
-    {
-      for (p_b_path_iterator it = probes_by_path.begin();
-           it != probes_by_path.end(); it++)
-	emit_vma_callback_probe_decl (s, it->first, (int64_t)0);
-    }
-  if (! probes_by_pid.empty())
-    {
-      for (p_b_pid_iterator it = probes_by_pid.begin();
-	   it != probes_by_pid.end(); it++)
-	emit_vma_callback_probe_decl (s, "", it->first);
-    }
-  s.op->newline(-1) << "};";
-  s.op->newline() << "#endif";
-
   s.op->newline() << "static struct stap_utrace_probe stap_utrace_probes[] = {";
   s.op->indent(1);
 
@@ -994,17 +975,6 @@ utrace_derived_probe_group::emit_module_init (systemtap_session& s)
   if (probes_by_path.empty() && probes_by_pid.empty())
     return;
 
-  s.op->newline();
-  s.op->newline() << "#ifdef STP_NEED_VMA_TRACKER";
-  s.op->newline() << "_stp_sym_init();";
-  s.op->newline() << "/* ---- utrace vma callbacks ---- */";
-  s.op->newline() << "for (i=0; i<ARRAY_SIZE(stap_utrace_vmcbs); i++) {";
-  s.op->indent(1);
-  s.op->newline() << "struct stap_task_finder_target *r = &stap_utrace_vmcbs[i];";
-  s.op->newline() << "rc = stap_register_task_finder_target(r);";
-  s.op->newline(-1) << "}";
-  s.op->newline() << "#endif";
-
   s.op->newline() << "/* ---- utrace probes ---- */";
   s.op->newline() << "for (i=0; i<ARRAY_SIZE(stap_utrace_probes); i++) {";
   s.op->indent(1);
diff --git a/tapsets.cxx b/tapsets.cxx
index 333914d0..a88cda79 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -4423,21 +4423,6 @@ uprobe_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline(-1) << "} stap_uprobes [MAXUPROBES];";
   s.op->newline() << "DEFINE_MUTEX(stap_uprobes_lock);"; // protects against concurrent registration/unregistration
 
-  // Emit vma callbacks.
-  s.op->newline() << "#ifdef STP_NEED_VMA_TRACKER";
-  s.op->newline() << "static struct stap_task_finder_target stap_uprobe_vmcbs[] = {";
-  s.op->indent(1);
-  for (unsigned i = 0; i < probes.size(); i++)
-    {
-      uprobe_derived_probe* p = probes[i];
-      if (p->pid != 0)
-	emit_vma_callback_probe_decl (s, "", p->pid);
-      else
-	emit_vma_callback_probe_decl (s, p->module, (int64_t)0);
-    }
-  s.op->newline(-1) << "};";
-  s.op->newline() << "#endif";
-
   s.op->newline() << "static struct stap_uprobe_spec {";
   s.op->newline(1) << "struct stap_task_finder_target finder;";
   s.op->newline() << "unsigned long address;";
@@ -4692,15 +4677,6 @@ void
 uprobe_derived_probe_group::emit_module_init (systemtap_session& s)
 {
   if (probes.empty()) return;
-  s.op->newline() << "#ifdef STP_NEED_VMA_TRACKER";
-  s.op->newline() << "_stp_sym_init();";
-  s.op->newline() << "/* ---- uprobe vma callbacks ---- */";
-  s.op->newline() << "for (i=0; i<ARRAY_SIZE(stap_uprobe_vmcbs); i++) {";
-  s.op->indent(1);
-  s.op->newline() << "struct stap_task_finder_target *r = &stap_uprobe_vmcbs[i];";
-  s.op->newline() << "rc = stap_register_task_finder_target(r);";
-  s.op->newline(-1) << "}";
-  s.op->newline() << "#endif";
 
   s.op->newline() << "/* ---- user probes ---- */";
 
diff --git a/task_finder.cxx b/task_finder.cxx
index de1c2208..ee9d746b 100644
--- a/task_finder.cxx
+++ b/task_finder.cxx
@@ -76,28 +76,4 @@ enable_task_finder(systemtap_session& s)
     s.task_finder_derived_probes = new task_finder_derived_probe_group();
 }
 
-// Helper function to emit vma tracker callbacks.
-void
-emit_vma_callback_probe_decl (systemtap_session& s,
-			      string path,
-			      int64_t pid)
-{
-  s.op->newline() << "{";
-  if (pid == 0)
-    {
-      s.op->line() << " .pathname=\"" << path << "\",";
-      s.op->line() << " .pid=0,";
-    }
-  else
-    {
-      s.op->line() << " .pathname=NULL,";
-      s.op->line() << " .pid=" << pid << ",";
-    }
-  s.op->line() << " .callback=NULL,";
-  s.op->line() << " .mmap_callback=&_stp_tf_mmap_cb,";
-  s.op->line() << " .munmap_callback=&_stp_tf_munmap_cb,";
-  s.op->line() << " .mprotect_callback=NULL,";
-  s.op->line() << " },";
-}
-
 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */
diff --git a/task_finder.h b/task_finder.h
index 99419e32..8f93c697 100644
--- a/task_finder.h
+++ b/task_finder.h
@@ -12,8 +12,6 @@
 // Declare that task_finder is needed in this session
 void enable_task_finder(systemtap_session& s);
 
-// Helper function to emit vma tracker callbacks.
-void emit_vma_callback_probe_decl (systemtap_session& s, std::string path, int64_t pid);
 
 #endif // TASK_FINDER_H
 
diff --git a/translate.cxx b/translate.cxx
index b8e22e49..69b16304 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -1140,6 +1140,22 @@ c_unparser::emit_module_init ()
   o->newline(-1) << "}";
   o->newline() << "#endif";
 
+  // PR10228: set up symbol table-related task finders
+  o->newline() << "#ifdef STP_NEED_VMA_TRACKER";
+  o->newline() << "_stp_sym_init();";
+  o->newline() << "for (i=0; i<_stp_num_modules; i++) {";
+  o->newline(1) << "if (_stp_modules[i]->vmcb) {";
+  o->newline(1) << "rc = stap_register_task_finder_target (_stp_modules[i]->vmcb);";
+  o->newline() << "if (rc) {"; 
+  o->newline(1) << "_stp_error ("
+                << "\"couldn't initialize task-finder for %s\\n\","
+                << "_stp_modules[i]->vmcb->pathname);";
+  o->newline() << "goto out;";
+  o->newline(-1) << "}";
+  o->newline(-1) << "}";
+  o->newline(-1) << "}";
+  o->newline() << "#endif";
+
   o->newline() << "(void) probe_point;";
   o->newline() << "(void) i;";
   o->newline() << "(void) j;";
@@ -4814,12 +4830,27 @@ dump_unwindsyms (Dwfl_Module *m,
     }
   c->output << "};\n";
 
+  mainfile = canonicalize_file_name(mainfile);
+
+  // PR10228: populate the task_finder_vmcb.
+  if (mainfile[0] == '/') // user-space module
+    {
+      // NB: runtime/sym.c
+      c->output << "static struct stap_task_finder_target _stp_vmcb_" << stpmod_idx << "= {\n";
+      c->output << ".pathname = " << lex_cast_qstring (mainfile) << ",\n";
+      c->output << ".mmap_callback = &_stp_tf_mmap_cb,\n";
+      c->output << ".munmap_callback = &_stp_tf_munmap_cb,\n";
+      c->output << "};\n";
+    }
+
   c->output << "static struct _stp_module _stp_module_" << stpmod_idx << " = {\n";
   c->output << ".name = " << lex_cast_qstring (modname) << ", \n";
-
-  mainfile = canonicalize_file_name(mainfile);
   c->output << ".path = " << lex_cast_qstring (mainfile) << ",\n";
 
+  // PR10228: populate the task_finder_vmcb.
+  if (mainfile[0] == '/') // user-space module
+      c->output << ".vmcb = & _stp_vmcb_" << stpmod_idx << ",\n";
+
   c->output << ".dwarf_module_base = 0x" << hex << base << dec << ", \n";
   c->output << ".eh_frame_addr = 0x" << hex << eh_addr << dec << ", \n";