include/linux/syscalls.h: add sys_renameat2() prototype

[karo-tx-linux.git] / include / linux / ftrace.h

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index f4233b195dab3e5fd64a0a1885c286374499d6ac..9212b017bc7236cfc63afe5c268cc741995a1af4 100644 (file)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -92,6 +92,7 @@ typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
  * STUB   - The ftrace_ops is just a place holder.
  * INITIALIZED - The ftrace_ops has already been initialized (first use time
  *            register_ftrace_function() is called, it will initialized the ops)
+ * DELETED - The ops are being deleted, do not let them be registered again.
  */
 enum {
        FTRACE_OPS_FL_ENABLED                   = 1 << 0,
@@ -103,13 +104,26 @@ enum {
        FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 6,
        FTRACE_OPS_FL_STUB                      = 1 << 7,
        FTRACE_OPS_FL_INITIALIZED               = 1 << 8,
+       FTRACE_OPS_FL_DELETED                   = 1 << 9,
 };
 
+/*
+ * Note, ftrace_ops can be referenced outside of RCU protection.
+ * (Although, for perf, the control ops prevent that). If ftrace_ops is
+ * allocated and not part of kernel core data, the unregistering of it will
+ * perform a scheduling on all CPUs to make sure that there are no more users.
+ * Depending on the load of the system that may take a bit of time.
+ *
+ * Any private data added must also take care not to be freed and if private
+ * data is added to a ftrace_ops that is in core code, the user of the
+ * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
+ */
 struct ftrace_ops {
        ftrace_func_t                   func;
        struct ftrace_ops               *next;
        unsigned long                   flags;
        int __percpu                    *disabled;
+       void                            *private;
 #ifdef CONFIG_DYNAMIC_FTRACE
        struct ftrace_hash              *notrace_hash;
        struct ftrace_hash              *filter_hash;
@@ -285,7 +299,7 @@ extern void
 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 extern void unregister_ftrace_function_probe_all(char *glob);
 
-extern int ftrace_text_reserved(void *start, void *end);
+extern int ftrace_text_reserved(const void *start, const void *end);
 
 extern int ftrace_nr_registered_ops(void);
 
@@ -316,12 +330,9 @@ enum {
 #define FTRACE_REF_MAX         ((1UL << 29) - 1)
 
 struct dyn_ftrace {
-       union {
-               unsigned long           ip; /* address of mcount call-site */
-               struct dyn_ftrace       *freelist;
-       };
+       unsigned long           ip; /* address of mcount call-site */
        unsigned long           flags;
-       struct dyn_arch_ftrace          arch;
+       struct dyn_arch_ftrace  arch;
 };
 
 int ftrace_force_update(void);
@@ -409,7 +420,7 @@ ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 
 /* defined in arch */
 extern int ftrace_ip_converted(unsigned long ip);
-extern int ftrace_dyn_arch_init(void *data);
+extern int ftrace_dyn_arch_init(void);
 extern void ftrace_replace_code(int enable);
 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 extern void ftrace_caller(void);
@@ -541,7 +552,7 @@ static inline __init int unregister_ftrace_command(char *cmd_name)
 {
        return -EINVAL;
 }
-static inline int ftrace_text_reserved(void *start, void *end)
+static inline int ftrace_text_reserved(const void *start, const void *end)
 {
        return 0;
 }