Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / kernel / trace / trace_event_perf.c

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 39c059ca670e64156e6681782ffa708c6b8d720f..19a359d5e6d58573cc1c74326e488a419b01b342 100644 (file)
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -21,17 +21,46 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
 /* Count the events in use (per event id, not per instance) */
 static int     total_ref_count;
 
+static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
+                                struct perf_event *p_event)
+{
+       /* No tracing, just counting, so no obvious leak */
+       if (!(p_event->attr.sample_type & PERF_SAMPLE_RAW))
+               return 0;
+
+       /* Some events are ok to be traced by non-root users... */
+       if (p_event->attach_state == PERF_ATTACH_TASK) {
+               if (tp_event->flags & TRACE_EVENT_FL_CAP_ANY)
+                       return 0;
+       }
+
+       /*
+        * ...otherwise raw tracepoint data can be a severe data leak,
+        * only allow root to have these.
+        */
+       if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       return 0;
+}
+
 static int perf_trace_event_init(struct ftrace_event_call *tp_event,
                                 struct perf_event *p_event)
 {
        struct hlist_head __percpu *list;
-       int ret = -ENOMEM;
+       int ret;
        int cpu;
 
+       ret = perf_trace_event_perm(tp_event, p_event);
+       if (ret)
+               return ret;
+
        p_event->tp_event = tp_event;
        if (tp_event->perf_refcount++ > 0)
                return 0;
 
+       ret = -ENOMEM;
+
        list = alloc_percpu(struct hlist_head);
        if (!list)
                goto fail;