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-rw-r--r--include/linux/ftrace.h27
1 files changed, 19 insertions, 8 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index f4233b195dab..9212b017bc72 100644
--- 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;
}