diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6459e141aac3..7fe7cc987dab 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -214,12 +214,10 @@ __setup("alloc_snapshot", boot_alloc_snapshot); static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; -static char *trace_boot_options __initdata; static int __init set_trace_boot_options(char *str) { strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); - trace_boot_options = trace_boot_options_buf; return 0; } __setup("trace_options=", set_trace_boot_options); @@ -1223,13 +1221,15 @@ static inline int run_tracer_selftest(struct tracer *type) static void add_tracer_options(struct trace_array *tr, struct tracer *t); +static void __init apply_trace_boot_options(void); + /** * register_tracer - register a tracer with the ftrace system. * @type - the plugin for the tracer * * Register a new plugin tracer. */ -int register_tracer(struct tracer *type) +int __init register_tracer(struct tracer *type) { struct tracer *t; int ret = 0; @@ -1288,6 +1288,9 @@ int register_tracer(struct tracer *type) /* Do we want this tracer to start on bootup? */ tracing_set_tracer(&global_trace, type->name); default_bootup_tracer = NULL; + + apply_trace_boot_options(); + /* disable other selftests, since this will break it. */ tracing_selftest_disabled = true; #ifdef CONFIG_FTRACE_STARTUP_TEST @@ -3589,6 +3592,7 @@ static int trace_set_options(struct trace_array *tr, char *option) int neg = 0; int ret = -ENODEV; int i; + size_t orig_len = strlen(option); cmp = strstrip(option); @@ -3612,9 +3616,37 @@ static int trace_set_options(struct trace_array *tr, char *option) mutex_unlock(&trace_types_lock); + /* + * If the first trailing whitespace is replaced with '\0' by strstrip, + * turn it back into a space. + */ + if (orig_len > strlen(option)) + option[strlen(option)] = ' '; + return ret; } +static void __init apply_trace_boot_options(void) +{ + char *buf = trace_boot_options_buf; + char *option; + + while (true) { + option = strsep(&buf, ","); + + if (!option) + break; + if (!*option) + continue; + + trace_set_options(&global_trace, option); + + /* Put back the comma to allow this to be called again */ + if (buf) + *(buf - 1) = ','; + } +} + static ssize_t tracing_trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) @@ -7248,12 +7280,7 @@ __init static int tracer_alloc_buffers(void) INIT_LIST_HEAD(&global_trace.events); list_add(&global_trace.list, &ftrace_trace_arrays); - while (trace_boot_options) { - char *option; - - option = strsep(&trace_boot_options, ","); - trace_set_options(&global_trace, option); - } + apply_trace_boot_options(); register_snapshot_cmd();