kernel/trace/ftrace_internal.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_KERNEL_FTRACE_INTERNAL_H
   3 #define  _LINUX_KERNEL_FTRACE_INTERNAL_H
   4
   5 #ifdef CONFIG_FUNCTION_TRACER
   6
   7 /*
   8  * Traverse the ftrace_global_list, invoking all entries.  The reason that we
   9  * can use rcu_dereference_raw_check() is that elements removed from this list
  10  * are simply leaked, so there is no need to interact with a grace-period
  11  * mechanism.  The rcu_dereference_raw_check() calls are needed to handle
  12  * concurrent insertions into the ftrace_global_list.
  13  *
  14  * Silly Alpha and silly pointer-speculation compiler optimizations!
  15  */
  16 #define do_for_each_ftrace_op(op, list)                 \
  17         op = rcu_dereference_raw_check(list);                   \
  18         do
  19
  20 /*
  21  * Optimized for just a single item in the list (as that is the normal case).
  22  */
  23 #define while_for_each_ftrace_op(op)                            \
  24         while (likely(op = rcu_dereference_raw_check((op)->next)) &&    \
  25                unlikely((op) != &ftrace_list_end))
  26
  27 extern struct ftrace_ops __rcu *ftrace_ops_list;
  28 extern struct ftrace_ops ftrace_list_end;
  29 extern struct mutex ftrace_lock;
  30 extern struct ftrace_ops global_ops;
  31
  32 #ifdef CONFIG_DYNAMIC_FTRACE
  33
  34 int ftrace_startup(struct ftrace_ops *ops, int command);
  35 int ftrace_shutdown(struct ftrace_ops *ops, int command);
  36 int ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs);
  37
  38 #else /* !CONFIG_DYNAMIC_FTRACE */
  39
  40 int __register_ftrace_function(struct ftrace_ops *ops);
  41 int __unregister_ftrace_function(struct ftrace_ops *ops);
  42 /* Keep as macros so we do not need to define the commands */
  43 # define ftrace_startup(ops, command)                                   \
  44         ({                                                              \
  45                 int ___ret = __register_ftrace_function(ops);           \
  46                 if (!___ret)                                            \
  47                         (ops)->flags |= FTRACE_OPS_FL_ENABLED;          \
  48                 ___ret;                                                 \
  49         })
  50 # define ftrace_shutdown(ops, command)                                  \
  51         ({                                                              \
  52                 int ___ret = __unregister_ftrace_function(ops);         \
  53                 if (!___ret)                                            \
  54                         (ops)->flags &= ~FTRACE_OPS_FL_ENABLED;         \
  55                 ___ret;                                                 \
  56         })
  57 static inline int
  58 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
  59 {
  60         return 1;
  61 }
  62 #endif /* CONFIG_DYNAMIC_FTRACE */
  63
  64 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  65 extern int ftrace_graph_active;
  66 void update_function_graph_func(void);
  67 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
  68 # define ftrace_graph_active 0
  69 static inline void update_function_graph_func(void) { }
  70 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
  71
  72 #else /* !CONFIG_FUNCTION_TRACER */
  73 #endif /* CONFIG_FUNCTION_TRACER */
  74
  75 #endif