diff options
Diffstat (limited to 'kernel/trace/trace_functions.c')
-rw-r--r-- | kernel/trace/trace_functions.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 9236d7e25a1..3a5fa08cedb 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -16,6 +16,8 @@ #include "trace.h" +static struct trace_array *func_trace; + static void start_function_trace(struct trace_array *tr) { tr->cpu = get_cpu(); @@ -34,6 +36,7 @@ static void stop_function_trace(struct trace_array *tr) static int function_trace_init(struct trace_array *tr) { + func_trace = tr; start_function_trace(tr); return 0; } @@ -48,12 +51,93 @@ static void function_trace_start(struct trace_array *tr) tracing_reset_online_cpus(tr); } +static void +function_stack_trace_call(unsigned long ip, unsigned long parent_ip) +{ + struct trace_array *tr = func_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + int pc; + + if (unlikely(!ftrace_function_enabled)) + return; + + /* + * Need to use raw, since this must be called before the + * recursive protection is performed. + */ + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) { + pc = preempt_count(); + /* + * skip over 5 funcs: + * __ftrace_trace_stack, + * __trace_stack, + * function_stack_trace_call + * ftrace_list_func + * ftrace_call + */ + __trace_stack(tr, data, flags, 5, pc); + } + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static struct ftrace_ops trace_stack_ops __read_mostly = +{ + .func = function_stack_trace_call, +}; + +/* Our two options */ +enum { + TRACE_FUNC_OPT_STACK = 0x1, +}; + +static struct tracer_opt func_opts[] = { +#ifdef CONFIG_STACKTRACE + { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, +#endif + { } /* Always set a last empty entry */ +}; + +static struct tracer_flags func_flags = { + .val = 0, /* By default: all flags disabled */ + .opts = func_opts +}; + +static int func_set_flag(u32 old_flags, u32 bit, int set) +{ + if (bit == TRACE_FUNC_OPT_STACK) { + /* do nothing if already set */ + if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK)) + return 0; + + if (set) + register_ftrace_function(&trace_stack_ops); + else + unregister_ftrace_function(&trace_stack_ops); + + return 0; + } + + return -EINVAL; +} + static struct tracer function_trace __read_mostly = { .name = "function", .init = function_trace_init, .reset = function_trace_reset, .start = function_trace_start, + .flags = &func_flags, + .set_flag = func_set_flag, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_function, #endif |