Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux...

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / tracepoint.c

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 0c05a4592047c7ccfdc323c1be24af40ac90cbe7..29f26540e9c9550fd1c099512e7b20beb21ce234 100644 (file)
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -112,7 +112,8 @@ tracepoint_entry_add_probe(struct tracepoint_entry *entry,
        int nr_probes = 0;
        struct tracepoint_func *old, *new;
 
-       WARN_ON(!probe);
+       if (WARN_ON(!probe))
+               return ERR_PTR(-EINVAL);
 
        debug_print_probes(entry);
        old = entry->funcs;
@@ -152,13 +153,18 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry,
 
        debug_print_probes(entry);
        /* (N -> M), (N > 1, M >= 0) probes */
-       for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
-               if (!probe ||
-                   (old[nr_probes].func == probe &&
-                    old[nr_probes].data == data))
-                       nr_del++;
+       if (probe) {
+               for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
+                       if (old[nr_probes].func == probe &&
+                            old[nr_probes].data == data)
+                               nr_del++;
+               }
        }
 
+       /*
+        * If probe is NULL, then nr_probes = nr_del = 0, and then the
+        * entire entry will be removed.
+        */
        if (nr_probes - nr_del == 0) {
                /* N -> 0, (N > 1) */
                entry->funcs = NULL;
@@ -173,8 +179,7 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry,
                if (new == NULL)
                        return ERR_PTR(-ENOMEM);
                for (i = 0; old[i].func; i++)
-                       if (probe &&
-                           (old[i].func != probe || old[i].data != data))
+                       if (old[i].func != probe || old[i].data != data)
                                new[j++] = old[i];
                new[nr_probes - nr_del].func = NULL;
                entry->refcount = nr_probes - nr_del;