Saves thread vma information.

2008-08-08  David Smith  <dsmith@redhat.com>

	* task_finder.c (__stp_tf_vm_cb): Added calls to save/delete vma
	information.
	* task_finder_vma.c (__stp_tf_vma_map_hash): New function.
	(__stp_tf_get_vma_map_entry_internal): Ditto.
	(stap_add_vma_map_info): Ditto.
	(stap_remove_vma_map_info): Ditto.
	(stap_find_vma_map_info): Ditto.

1 files changed, 132 insertions, 0 deletions

diff --git a/runtime/task_finder_vma.c b/runtime/task_finder_vma.c
index c0a018ab..9d43e36c 100644
--- a/runtime/task_finder_vma.c
+++ b/runtime/task_finder_vma.c
@@ -34,6 +34,8 @@ static struct hlist_head __stp_tf_vma_free_list[1];
 
 static struct hlist_head __stp_tf_vma_table[__STP_TF_TABLE_SIZE];
 
+static struct hlist_head __stp_tf_vma_map[__STP_TF_TABLE_SIZE];
+
 // __stp_tf_vma_initialize():  Initialize the free list.  Grabs the
 // mutex.
 static void
@@ -171,3 +173,133 @@ __stp_tf_remove_vma_entry(struct __stp_tf_vma_entry *entry)
 	}
 	return 0;
 }
+
+
+
+// __stp_tf_vma_map_hash(): Compute the vma map hash.
+static inline u32
+__stp_tf_vma_map_hash(struct task_struct *tsk)
+{
+    return (jhash_1word(tsk->pid, 0) & (__STP_TF_TABLE_SIZE - 1));
+}
+
+// Get vma_entry if the vma is present in the vma map hash table.
+// Returns NULL if not present.  The __stp_tf_vma_mutex must be locked
+// before calling this function.
+static struct __stp_tf_vma_entry *
+__stp_tf_get_vma_map_entry_internal(struct task_struct *tsk,
+				    unsigned long vm_start)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct __stp_tf_vma_entry *entry;
+
+	head = &__stp_tf_vma_map[__stp_tf_vma_map_hash(tsk)];
+	hlist_for_each_entry(entry, node, head, hlist) {
+		if (tsk->pid == entry->pid
+		    && vm_start == entry->addr) {
+			mutex_unlock(&__stp_tf_vma_mutex);
+			return entry;
+		}
+	}
+	return NULL;
+}
+
+
+// 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)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct __stp_tf_vma_entry *entry;
+
+	mutex_lock(&__stp_tf_vma_mutex);
+	entry = __stp_tf_get_vma_map_entry_internal(tsk, vm_start);
+	if (entry != NULL) {
+#if 0
+		printk(KERN_NOTICE
+		       "vma (pid: %d, vm_start: 0x%lx) present?\n",
+		       tsk->pid, entry->vm_start);
+#endif
+		mutex_unlock(&__stp_tf_vma_mutex);
+		return -EBUSY;	/* Already there */
+	}
+
+	// Get an element from the free list.
+	entry = __stp_tf_vma_get_free_entry();
+	if (!entry) {
+		mutex_unlock(&__stp_tf_vma_mutex);
+		return -ENOMEM;
+	}
+
+	// Fill in the info
+	entry->pid = tsk->pid;
+	//entry->addr = addr; ???
+	entry->vm_start = vm_start;
+	entry->vm_end = vm_end;
+	entry->vm_pgoff = vm_pgoff;
+
+	head = &__stp_tf_vma_map[__stp_tf_vma_map_hash(tsk)];
+	hlist_add_head(&entry->hlist, head);
+	mutex_unlock(&__stp_tf_vma_mutex);
+	return 0;
+}
+
+
+// Remove the vma entry from the vma hash table.
+static int
+stap_remove_vma_map_info(struct task_struct *tsk, unsigned long vm_start,
+			     unsigned long vm_end, unsigned long vm_pgoff)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct __stp_tf_vma_entry *entry;
+
+	mutex_lock(&__stp_tf_vma_mutex);
+	entry = __stp_tf_get_vma_map_entry_internal(tsk, vm_start);
+	if (entry != NULL) {
+		hlist_del(&entry->hlist);
+		__stp_tf_vma_put_free_entry(entry);
+	}
+	mutex_unlock(&__stp_tf_vma_mutex);
+	return 0;
+}
+
+// Finds vma info if the vma is present in the vma map hash table.
+// Returns ESRCH if not present.  The __stp_tf_vma_mutex must *not* be
+// locked before calling this function.
+static int
+stap_find_vma_map_info(struct task_struct *tsk, unsigned long vm_addr,
+		       unsigned long *vm_start, unsigned long *vm_end,
+		       unsigned long *vm_pgoff)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct __stp_tf_vma_entry *entry;
+	struct __stp_tf_vma_entry *found_entry = NULL;
+	int rc = ESRCH;
+
+	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
+		    && vm_addr >= entry->vm_start
+		    && vm_addr < entry->vm_end) {
+			found_entry = entry;
+			break;
+		}
+	}
+	if (found_entry != NULL) {
+		if (vm_start != NULL)
+			*vm_start = found_entry->vm_start;
+		if (vm_end != NULL)
+			*vm_end = found_entry->vm_end;
+		if (vm_pgoff != NULL)
+			*vm_pgoff = found_entry->vm_pgoff;
+		rc = 0;
+	}
+	mutex_unlock(&__stp_tf_vma_mutex);
+	return rc;
+}