Move vma module tracking from pr6866 branch to master.

* tapsets.cxx (utrace_derived_probe_group::emit_module_decls):
  Always emit vm callback probe for __stp_tf_vm_cb.
* runtime/task_finder.c (__stp_tf_vm_cb): Always expose, move _stp_dbug
  statements under ifdef DEBUG_TASK_FINDER_VMA. Find  and record
  corresponding module when vm_path not NULL.
* runtime/task_finder_vma.c (struct __stp_tf_vma_entry): Add _stp_module.
  (stap_add_vma_map_info): Add _stp_module argument and assign.
  (__stp_tf_get_vma_entry_addr): New static function to get
  the __stp_tf_vma_entry given an address.

2 files changed, 45 insertions, 7 deletions

diff --git a/runtime/task_finder.c b/runtime/task_finder.c
index 9db713c3..ae381a41 100644
--- a/runtime/task_finder.c
+++ b/runtime/task_finder.c
@@ -55,7 +55,6 @@ typedef int (*stap_task_finder_vm_callback)(struct stap_task_finder_target *tgt,
 					    unsigned long vm_end,
 					    unsigned long vm_pgoff);
 
-#ifdef DEBUG_TASK_FINDER_VMA
 static int __stp_tf_vm_cb(struct stap_task_finder_target *tgt,
 		   struct task_struct *tsk,
 		   int map_p, char *vm_path,
@@ -63,21 +62,32 @@ static int __stp_tf_vm_cb(struct stap_task_finder_target *tgt,
 		   unsigned long vm_end,
 		   unsigned long vm_pgoff)
 {
+  int i;
+#ifdef DEBUG_TASK_FINDER_VMA
 	_stp_dbug(__FUNCTION__, __LINE__,
 		  "vm_cb: tsk %d:%d path %s, start 0x%08lx, end 0x%08lx, offset 0x%lx\n",
 		  tsk->pid, map_p, vm_path, vm_start, vm_end, vm_pgoff);
+#endif
 	if (map_p) {
-		// FIXME: What should we do with vm_path?  We can't save
-		// the vm_path pointer itself, but we don't have any
-		// storage space allocated to save it in...
-		stap_add_vma_map_info(tsk, vm_start, vm_end, vm_pgoff);
+	  struct _stp_module *module = NULL;
+	  if (vm_path != NULL)
+	    for (i = 0; i < _stp_num_modules; i++)
+	      if (strcmp(vm_path, _stp_modules[i]->name) == 0)
+		{
+#ifdef DEBUG_TASK_FINDER_VMA
+		  _stp_dbug(__FUNCTION__, __LINE__,
+			    "vm_cb: matched path %s to module\n", vm_path);
+#endif
+		  module = _stp_modules[i];
+		  break;
+		}
+	  stap_add_vma_map_info(tsk, vm_start, vm_end, vm_pgoff, module);
 	}
 	else {
 		stap_remove_vma_map_info(tsk, vm_start, vm_end, vm_pgoff);
 	}
 	return 0;
 }
-#endif
 
 struct stap_task_finder_target {
 /* private: */
diff --git a/runtime/task_finder_vma.c b/runtime/task_finder_vma.c
index 4dce4be8..87a32fe5 100644
--- a/runtime/task_finder_vma.c
+++ b/runtime/task_finder_vma.c
@@ -25,6 +25,9 @@ struct __stp_tf_vma_entry {
 	unsigned long vm_end;
 	unsigned long vm_pgoff;
 	// Is that enough?  Should we store a dcookie for vm_file?
+
+	// Module that this vma entry is mapped from, if any.                   
+	struct _stp_module *module;
 };
 
 static struct __stp_tf_vma_entry
@@ -211,7 +214,8 @@ __stp_tf_get_vma_map_entry_internal(struct task_struct *tsk,
 // Add the vma info to the vma map hash table.
 static int
 stap_add_vma_map_info(struct task_struct *tsk, unsigned long vm_start,
-			  unsigned long vm_end, unsigned long vm_pgoff)
+		      unsigned long vm_end, unsigned long vm_pgoff,
+		      struct _stp_module *module)
 {
 	struct hlist_head *head;
 	struct hlist_node *node;
@@ -242,6 +246,7 @@ stap_add_vma_map_info(struct task_struct *tsk, unsigned long vm_start,
 	entry->vm_start = vm_start;
 	entry->vm_end = vm_end;
 	entry->vm_pgoff = vm_pgoff;
+	entry->module = module;
 
 	head = &__stp_tf_vma_map[__stp_tf_vma_map_hash(tsk)];
 	hlist_add_head(&entry->hlist, head);
@@ -305,3 +310,26 @@ stap_find_vma_map_info(struct task_struct *tsk, unsigned long vm_addr,
 	mutex_unlock(&__stp_tf_vma_mutex);
 	return rc;
 }
+
+// Get vma_entry of the address (vm_start/vm_end) if the vma is
+// present in the vma hash table containing.
+// Returns NULL if not present.
+static struct __stp_tf_vma_entry *
+__stp_tf_get_vma_entry_addr(struct task_struct *tsk, unsigned long addr)
+{
+  struct hlist_head *head;
+  struct hlist_node *node;
+  struct __stp_tf_vma_entry *entry;
+  
+  mutex_lock(&__stp_tf_vma_mutex);
+  head = &__stp_tf_vma_map[__stp_tf_vma_map_hash(tsk)];
+  hlist_for_each_entry(entry, node, head, hlist) {
+    if (tsk->pid == entry->pid
+	&& addr >= entry->vm_start && addr < entry->vm_end) {
+      mutex_unlock(&__stp_tf_vma_mutex);
+      return entry;
+    }
+  }
+  mutex_unlock(&__stp_tf_vma_mutex);
+  return NULL;
+}