tracing/uprobes: Fail to unregister if probe event files are in use

[pandora-kernel.git] / kernel / trace / trace_uprobe.c

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index a23d2d7..272261b 100644 (file)
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -70,7 +70,7 @@ struct trace_uprobe {
        (sizeof(struct probe_arg) * (n)))
 
 static int register_uprobe_event(struct trace_uprobe *tu);
-static void unregister_uprobe_event(struct trace_uprobe *tu);
+static int unregister_uprobe_event(struct trace_uprobe *tu);
 
 static DEFINE_MUTEX(uprobe_lock);
 static LIST_HEAD(uprobe_list);
@@ -164,11 +164,17 @@ static struct trace_uprobe *find_probe_event(const char *event, const char *grou
 }
 
 /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
-static void unregister_trace_uprobe(struct trace_uprobe *tu)
+static int unregister_trace_uprobe(struct trace_uprobe *tu)
 {
+       int ret;
+
+       ret = unregister_uprobe_event(tu);
+       if (ret)
+               return ret;
+
        list_del(&tu->list);
-       unregister_uprobe_event(tu);
        free_trace_uprobe(tu);
+       return 0;
 }
 
 /* Register a trace_uprobe and probe_event */
@@ -181,9 +187,12 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
 
        /* register as an event */
        old_tp = find_probe_event(tu->call.name, tu->call.class->system);
-       if (old_tp)
+       if (old_tp) {
                /* delete old event */
-               unregister_trace_uprobe(old_tp);
+               ret = unregister_trace_uprobe(old_tp);
+               if (ret)
+                       goto end;
+       }
 
        ret = register_uprobe_event(tu);
        if (ret) {
@@ -256,6 +265,8 @@ static int create_trace_uprobe(int argc, char **argv)
                group = UPROBE_EVENT_SYSTEM;
 
        if (is_delete) {
+               int ret;
+
                if (!event) {
                        pr_info("Delete command needs an event name.\n");
                        return -EINVAL;
@@ -269,9 +280,9 @@ static int create_trace_uprobe(int argc, char **argv)
                        return -ENOENT;
                }
                /* delete an event */
-               unregister_trace_uprobe(tu);
+               ret = unregister_trace_uprobe(tu);
                mutex_unlock(&uprobe_lock);
-               return 0;
+               return ret;
        }
 
        if (argc < 2) {
@@ -408,16 +419,20 @@ fail_address_parse:
        return ret;
 }
 
-static void cleanup_all_probes(void)
+static int cleanup_all_probes(void)
 {
        struct trace_uprobe *tu;
+       int ret = 0;
 
        mutex_lock(&uprobe_lock);
        while (!list_empty(&uprobe_list)) {
                tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
-               unregister_trace_uprobe(tu);
+               ret = unregister_trace_uprobe(tu);
+               if (ret)
+                       break;
        }
        mutex_unlock(&uprobe_lock);
+       return ret;
 }
 
 /* Probes listing interfaces */
@@ -462,8 +477,13 @@ static const struct seq_operations probes_seq_op = {
 
 static int probes_open(struct inode *inode, struct file *file)
 {
-       if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
-               cleanup_all_probes();
+       int ret;
+
+       if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+               ret = cleanup_all_probes();
+               if (ret)
+                       return ret;
+       }
 
        return seq_open(file, &probes_seq_op);
 }
@@ -968,12 +988,17 @@ static int register_uprobe_event(struct trace_uprobe *tu)
        return ret;
 }
 
-static void unregister_uprobe_event(struct trace_uprobe *tu)
+static int unregister_uprobe_event(struct trace_uprobe *tu)
 {
+       int ret;
+
        /* tu->event is unregistered in trace_remove_event_call() */
-       trace_remove_event_call(&tu->call);
+       ret = trace_remove_event_call(&tu->call);
+       if (ret)
+               return ret;
        kfree(tu->call.print_fmt);
        tu->call.print_fmt = NULL;
+       return 0;
 }
 
 /* Make a trace interface for controling probe points */