Merge tag 'sysctl-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof...

[linux-block.git] / kernel / trace / ftrace.c

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 674add0aafb3131a5a5e331e02dd7937d06b288a..f8db59c3a601b7f1299e970960e2a33ef45f53c2 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -86,7 +86,7 @@ struct ftrace_ops ftrace_list_end __read_mostly = {
 
 /* 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;
@@ -3065,40 +3065,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command)
        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;
@@ -7267,9 +7233,6 @@ core_initcall(ftrace_nodyn_init);
 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)
 {
 }
@@ -7909,62 +7872,6 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 }
 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
 
-static bool is_permanent_ops_registered(void)
-{
-       struct ftrace_ops *op;
-
-       do_for_each_ftrace_op(op, ftrace_ops_list) {
-               if (op->flags & FTRACE_OPS_FL_PERMANENT)
-                       return true;
-       } while_for_each_ftrace_op(op);
-
-       return false;
-}
-
-int
-ftrace_enable_sysctl(struct ctl_table *table, int write,
-                    void *buffer, size_t *lenp, loff_t *ppos)
-{
-       int ret = -ENODEV;
-
-       mutex_lock(&ftrace_lock);
-
-       if (unlikely(ftrace_disabled))
-               goto out;
-
-       ret = proc_dointvec(table, write, buffer, lenp, ppos);
-
-       if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
-               goto out;
-
-       if (ftrace_enabled) {
-
-               /* we are starting ftrace again */
-               if (rcu_dereference_protected(ftrace_ops_list,
-                       lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
-                       update_ftrace_function();
-
-               ftrace_startup_sysctl();
-
-       } else {
-               if (is_permanent_ops_registered()) {
-                       ftrace_enabled = true;
-                       ret = -EBUSY;
-                       goto out;
-               }
-
-               /* stopping ftrace calls (just send to ftrace_stub) */
-               ftrace_trace_function = ftrace_stub;
-
-               ftrace_shutdown_sysctl();
-       }
-
-       last_ftrace_enabled = !!ftrace_enabled;
- out:
-       mutex_unlock(&ftrace_lock);
-       return ret;
-}
-
 static int symbols_cmp(const void *a, const void *b)
 {
        const char **str_a = (const char **) a;
@@ -8026,3 +7933,119 @@ int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *a
                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;
+
+       do_for_each_ftrace_op(op, ftrace_ops_list) {
+               if (op->flags & FTRACE_OPS_FL_PERMANENT)
+                       return true;
+       } while_for_each_ftrace_op(op);
+
+       return false;
+}
+
+static int
+ftrace_enable_sysctl(struct ctl_table *table, int write,
+                    void *buffer, size_t *lenp, loff_t *ppos)
+{
+       int ret = -ENODEV;
+
+       mutex_lock(&ftrace_lock);
+
+       if (unlikely(ftrace_disabled))
+               goto out;
+
+       ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+       if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
+               goto out;
+
+       if (ftrace_enabled) {
+
+               /* we are starting ftrace again */
+               if (rcu_dereference_protected(ftrace_ops_list,
+                       lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
+                       update_ftrace_function();
+
+               ftrace_startup_sysctl();
+
+       } else {
+               if (is_permanent_ops_registered()) {
+                       ftrace_enabled = true;
+                       ret = -EBUSY;
+                       goto out;
+               }
+
+               /* stopping ftrace calls (just send to ftrace_stub) */
+               ftrace_trace_function = ftrace_stub;
+
+               ftrace_shutdown_sysctl();
+       }
+
+       last_ftrace_enabled = !!ftrace_enabled;
+ out:
+       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