1 files changed, 55 insertions, 0 deletions

diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index d2cdbabb4ead..dc98309e839a 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -17,6 +17,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
         case TRACE_GRAPH_ENT:
         case TRACE_GRAPH_RET:
         case TRACE_HW_BRANCHES:
+        case TRACE_KSYM:
                 return 1;
         }
         return 0;
@@ -808,3 +809,57 @@ trace_selftest_startup_hw_branches(struct tracer *trace,
         return ret;
 }
 #endif /* CONFIG_HW_BRANCH_TRACER */
+
+#ifdef CONFIG_KSYM_TRACER
+static int ksym_selftest_dummy;
+
+int
+trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr)
+{
+        unsigned long count;
+        int ret;
+
+        /* start the tracing */
+        ret = tracer_init(trace, tr);
+        if (ret) {
+                warn_failed_init_tracer(trace, ret);
+                return ret;
+        }
+
+        ksym_selftest_dummy = 0;
+        /* Register the read-write tracing request */
+
+        ret = process_new_ksym_entry("ksym_selftest_dummy",
+                                     HW_BREAKPOINT_R | HW_BREAKPOINT_W,
+                                        (unsigned long)(&ksym_selftest_dummy));
+
+        if (ret < 0) {
+                printk(KERN_CONT "ksym_trace read-write startup test failed\n");
+                goto ret_path;
+        }
+        /* Perform a read and a write operation over the dummy variable to
+         * trigger the tracer
+         */
+        if (ksym_selftest_dummy == 0)
+                ksym_selftest_dummy++;
+
+        /* stop the tracing. */
+        tracing_stop();
+        /* check the trace buffer */
+        ret = trace_test_buffer(tr, &count);
+        trace->reset(tr);
+        tracing_start();
+
+        /* read & write operations - one each is performed on the dummy variable
+         * triggering two entries in the trace buffer
+         */
+        if (!ret && count != 2) {
+                printk(KERN_CONT "Ksym tracer startup test failed");
+                ret = -1;
+        }
+
+ret_path:
+        return ret;
+}
+#endif /* CONFIG_KSYM_TRACER */
+