/* ftrace_enabled is a method to turn ftrace on or off */
int ftrace_enabled __read_mostly;
-static int last_ftrace_enabled;
+static int __maybe_unused last_ftrace_enabled;
/* Current function tracing op */
struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
return 0;
}
-static void ftrace_startup_sysctl(void)
-{
- int command;
-
- if (unlikely(ftrace_disabled))
- return;
-
- /* Force update next time */
- saved_ftrace_func = NULL;
- /* ftrace_start_up is true if we want ftrace running */
- if (ftrace_start_up) {
- command = FTRACE_UPDATE_CALLS;
- if (ftrace_graph_active)
- command |= FTRACE_START_FUNC_RET;
- ftrace_startup_enable(command);
- }
-}
-
-static void ftrace_shutdown_sysctl(void)
-{
- int command;
-
- if (unlikely(ftrace_disabled))
- return;
-
- /* ftrace_start_up is true if ftrace is running */
- if (ftrace_start_up) {
- command = FTRACE_DISABLE_CALLS;
- if (ftrace_graph_active)
- command |= FTRACE_STOP_FUNC_RET;
- ftrace_run_update_code(command);
- }
-}
-
static u64 ftrace_update_time;
unsigned long ftrace_update_tot_cnt;
unsigned long ftrace_number_of_pages;
static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
static inline void ftrace_startup_all(int command) { }
-# define ftrace_startup_sysctl() do { } while (0)
-# define ftrace_shutdown_sysctl() do { } while (0)
-
static void ftrace_update_trampoline(struct ftrace_ops *ops)
{
}
static void
ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
- unsigned int prev_state,
struct task_struct *prev,
- struct task_struct *next)
+ struct task_struct *next,
+ unsigned int prev_state)
{
struct trace_array *tr = data;
struct trace_pid_list *pid_list;
}
EXPORT_SYMBOL_GPL(unregister_ftrace_function);
+static int symbols_cmp(const void *a, const void *b)
+{
+ const char **str_a = (const char **) a;
+ const char **str_b = (const char **) b;
+
+ return strcmp(*str_a, *str_b);
+}
+
+struct kallsyms_data {
+ unsigned long *addrs;
+ const char **syms;
+ size_t cnt;
+ size_t found;
+};
+
+static int kallsyms_callback(void *data, const char *name,
+ struct module *mod, unsigned long addr)
+{
+ struct kallsyms_data *args = data;
+
+ if (!bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp))
+ return 0;
+
+ addr = ftrace_location(addr);
+ if (!addr)
+ return 0;
+
+ args->addrs[args->found++] = addr;
+ return args->found == args->cnt ? 1 : 0;
+}
+
+/**
+ * ftrace_lookup_symbols - Lookup addresses for array of symbols
+ *
+ * @sorted_syms: array of symbols pointers symbols to resolve,
+ * must be alphabetically sorted
+ * @cnt: number of symbols/addresses in @syms/@addrs arrays
+ * @addrs: array for storing resulting addresses
+ *
+ * This function looks up addresses for array of symbols provided in
+ * @syms array (must be alphabetically sorted) and stores them in
+ * @addrs array, which needs to be big enough to store at least @cnt
+ * addresses.
+ *
+ * This function returns 0 if all provided symbols are found,
+ * -ESRCH otherwise.
+ */
+int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
+{
+ struct kallsyms_data args;
+ int err;
+
+ args.addrs = addrs;
+ args.syms = sorted_syms;
+ args.cnt = cnt;
+ args.found = 0;
+ err = kallsyms_on_each_symbol(kallsyms_callback, &args);
+ if (err < 0)
+ return err;
+ return args.found == args.cnt ? 0 : -ESRCH;
+}
+
+#ifdef CONFIG_SYSCTL
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void ftrace_startup_sysctl(void)
+{
+ int command;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ /* Force update next time */
+ saved_ftrace_func = NULL;
+ /* ftrace_start_up is true if we want ftrace running */
+ if (ftrace_start_up) {
+ command = FTRACE_UPDATE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_START_FUNC_RET;
+ ftrace_startup_enable(command);
+ }
+}
+
+static void ftrace_shutdown_sysctl(void)
+{
+ int command;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ /* ftrace_start_up is true if ftrace is running */
+ if (ftrace_start_up) {
+ command = FTRACE_DISABLE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_STOP_FUNC_RET;
+ ftrace_run_update_code(command);
+ }
+}
+#else
+# define ftrace_startup_sysctl() do { } while (0)
+# define ftrace_shutdown_sysctl() do { } while (0)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
static bool is_permanent_ops_registered(void)
{
struct ftrace_ops *op;
return false;
}
-int
+static int
ftrace_enable_sysctl(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
mutex_unlock(&ftrace_lock);
return ret;
}
+
+static struct ctl_table ftrace_sysctls[] = {
+ {
+ .procname = "ftrace_enabled",
+ .data = &ftrace_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = ftrace_enable_sysctl,
+ },
+ {}
+};
+
+static int __init ftrace_sysctl_init(void)
+{
+ register_sysctl_init("kernel", ftrace_sysctls);
+ return 0;
+}
+late_initcall(ftrace_sysctl_init);
+#endif
projects / people / ms / linux.git / blobdiff