diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/tracepoint.h | 95 |
1 files changed, 72 insertions, 23 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 8d5e4f6d96d..9a59d1f98cd 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -20,12 +20,17 @@ struct module; struct tracepoint; +struct tracepoint_func { + void *func; + void *data; +}; + struct tracepoint { const char *name; /* Tracepoint name */ int state; /* State. */ void (*regfunc)(void); void (*unregfunc)(void); - void **funcs; + struct tracepoint_func *funcs; } __attribute__((aligned(32))); /* * Aligned on 32 bytes because it is * globally visible and gcc happily @@ -37,16 +42,19 @@ struct tracepoint { * Connect a probe to a tracepoint. * Internal API, should not be used directly. */ -extern int tracepoint_probe_register(const char *name, void *probe); +extern int tracepoint_probe_register(const char *name, void *probe, void *data); /* * Disconnect a probe from a tracepoint. * Internal API, should not be used directly. */ -extern int tracepoint_probe_unregister(const char *name, void *probe); +extern int +tracepoint_probe_unregister(const char *name, void *probe, void *data); -extern int tracepoint_probe_register_noupdate(const char *name, void *probe); -extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); +extern int tracepoint_probe_register_noupdate(const char *name, void *probe, + void *data); +extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe, + void *data); extern void tracepoint_probe_update_all(void); struct tracepoint_iter { @@ -102,17 +110,27 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin, /* * it_func[0] is never NULL because there is at least one element in the array * when the array itself is non NULL. + * + * Note, the proto and args passed in includes "__data" as the first parameter. + * The reason for this is to handle the "void" prototype. If a tracepoint + * has a "void" prototype, then it is invalid to declare a function + * as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just + * "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto". */ #define __DO_TRACE(tp, proto, args) \ do { \ - void **it_func; \ + struct tracepoint_func *it_func_ptr; \ + void *it_func; \ + void *__data; \ \ rcu_read_lock_sched_notrace(); \ - it_func = rcu_dereference_sched((tp)->funcs); \ - if (it_func) { \ + it_func_ptr = rcu_dereference_sched((tp)->funcs); \ + if (it_func_ptr) { \ do { \ - ((void(*)(proto))(*it_func))(args); \ - } while (*(++it_func)); \ + it_func = (it_func_ptr)->func; \ + __data = (it_func_ptr)->data; \ + ((void(*)(proto))(it_func))(args); \ + } while ((++it_func_ptr)->func); \ } \ rcu_read_unlock_sched_notrace(); \ } while (0) @@ -122,23 +140,29 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin, * not add unwanted padding between the beginning of the section and the * structure. Force alignment to the same alignment as the section start. */ -#define DECLARE_TRACE(name, proto, args) \ +#define __DECLARE_TRACE(name, proto, args, data_proto, data_args) \ extern struct tracepoint __tracepoint_##name; \ static inline void trace_##name(proto) \ { \ if (unlikely(__tracepoint_##name.state)) \ __DO_TRACE(&__tracepoint_##name, \ - TP_PROTO(proto), TP_ARGS(args)); \ + TP_PROTO(data_proto), \ + TP_ARGS(data_args)); \ } \ - static inline int register_trace_##name(void (*probe)(proto)) \ + static inline int \ + register_trace_##name(void (*probe)(data_proto), void *data) \ { \ - return tracepoint_probe_register(#name, (void *)probe); \ + return tracepoint_probe_register(#name, (void *)probe, \ + data); \ } \ - static inline int unregister_trace_##name(void (*probe)(proto)) \ + static inline int \ + unregister_trace_##name(void (*probe)(data_proto), void *data) \ { \ - return tracepoint_probe_unregister(#name, (void *)probe);\ + return tracepoint_probe_unregister(#name, (void *)probe, \ + data); \ } \ - static inline void check_trace_callback_type_##name(void (*cb)(proto)) \ + static inline void \ + check_trace_callback_type_##name(void (*cb)(data_proto)) \ { \ } @@ -158,20 +182,22 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin, EXPORT_SYMBOL(__tracepoint_##name) #else /* !CONFIG_TRACEPOINTS */ -#define DECLARE_TRACE(name, proto, args) \ - static inline void _do_trace_##name(struct tracepoint *tp, proto) \ - { } \ +#define __DECLARE_TRACE(name, proto, args, data_proto, data_args) \ static inline void trace_##name(proto) \ { } \ - static inline int register_trace_##name(void (*probe)(proto)) \ + static inline int \ + register_trace_##name(void (*probe)(data_proto), \ + void *data) \ { \ return -ENOSYS; \ } \ - static inline int unregister_trace_##name(void (*probe)(proto)) \ + static inline int \ + unregister_trace_##name(void (*probe)(data_proto), \ + void *data) \ { \ return -ENOSYS; \ } \ - static inline void check_trace_callback_type_##name(void (*cb)(proto)) \ + static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \ { \ } @@ -181,6 +207,29 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin, #define EXPORT_TRACEPOINT_SYMBOL(name) #endif /* CONFIG_TRACEPOINTS */ + +/* + * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype + * (void). "void" is a special value in a function prototype and can + * not be combined with other arguments. Since the DECLARE_TRACE() + * macro adds a data element at the beginning of the prototype, + * we need a way to differentiate "(void *data, proto)" from + * "(void *data, void)". The second prototype is invalid. + * + * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype + * and "void *__data" as the callback prototype. + * + * DECLARE_TRACE() passes "proto" as the tracepoint protoype and + * "void *__data, proto" as the callback prototype. + */ +#define DECLARE_TRACE_NOARGS(name) \ + __DECLARE_TRACE(name, void, , void *__data, __data) + +#define DECLARE_TRACE(name, proto, args) \ + __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ + PARAMS(void *__data, proto), \ + PARAMS(__data, args)) + #endif /* DECLARE_TRACE */ #ifndef TRACE_EVENT |