diff options
Diffstat (limited to 'kernel/trace/trace_selftest.c')
| -rw-r--r-- | kernel/trace/trace_selftest.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 00dd6485bdd..71f2edb0fd8 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; @@ -807,3 +808,55 @@ 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_ENTRY, HW_BREAKPOINT_RW, + (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 */ + |