tracepoint: Reduce duplication of __DO_TRACE_CALL

The logic for invoking __DO_TRACE_CALL was extracted to a static inline
function called __rust_do_trace_##name so that Rust can call it
directly. This logic does not include the static branch, to avoid a
function call when the tracepoint is disabled.

Since the C code needs to perform the same logic after checking the
static key, this logic is currently duplicated. Thus, remove this
duplication by having C call the static inline function too.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241212131237.1988409-1-aliceryhl@google.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 76d9055b2cff1cadaf402895524b8adeca090a15..a351763e6965a2c79c37a5e15c0502c878db739e 100644 (file)
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -218,7 +218,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 #define __DEFINE_RUST_DO_TRACE(name, proto, args)                      \
        notrace void rust_do_trace_##name(proto)                        \
        {                                                               \
-               __rust_do_trace_##name(args);                           \
+               __do_trace_##name(args);                                \
        }
 
 /*
@@ -268,7 +268,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 
 #define __DECLARE_TRACE(name, proto, args, cond, data_proto)           \
        __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) \
-       static inline void __rust_do_trace_##name(proto)                \
+       static inline void __do_trace_##name(proto)                     \
        {                                                               \
                if (cond) {                                             \
                        guard(preempt_notrace)();                       \
@@ -277,12 +277,8 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
        }                                                               \
        static inline void trace_##name(proto)                          \
        {                                                               \
-               if (static_branch_unlikely(&__tracepoint_##name.key)) { \
-                       if (cond) {                                     \
-                               guard(preempt_notrace)();               \
-                               __DO_TRACE_CALL(name, TP_ARGS(args));   \
-                       }                                               \
-               }                                                       \
+               if (static_branch_unlikely(&__tracepoint_##name.key))   \
+                       __do_trace_##name(args);                        \
                if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {             \
                        WARN_ONCE(!rcu_is_watching(),                   \
                                  "RCU not watching for tracepoint");   \
@@ -291,7 +287,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 
 #define __DECLARE_TRACE_SYSCALL(name, proto, args, data_proto)         \
        __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) \
-       static inline void __rust_do_trace_##name(proto)                \
+       static inline void __do_trace_##name(proto)                     \
        {                                                               \
                guard(rcu_tasks_trace)();                               \
                __DO_TRACE_CALL(name, TP_ARGS(args));                   \
@@ -299,10 +295,8 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
        static inline void trace_##name(proto)                          \
        {                                                               \
                might_fault();                                          \
-               if (static_branch_unlikely(&__tracepoint_##name.key)) { \
-                       guard(rcu_tasks_trace)();                       \
-                       __DO_TRACE_CALL(name, TP_ARGS(args));           \
-               }                                                       \
+               if (static_branch_unlikely(&__tracepoint_##name.key))   \
+                       __do_trace_##name(args);                        \
                if (IS_ENABLED(CONFIG_LOCKDEP)) {                       \
                        WARN_ONCE(!rcu_is_watching(),                   \
                                  "RCU not watching for tracepoint");   \