tracepoint: Do not warn for unused event that is exported

There are a few generic events that may only be used by modules. They are
defined and then set with EXPORT_TRACEPOINT*(). Mark events that are
exported as being used, even though they still waste memory in the kernel
proper.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas.schier@linux.dev>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/20251022004453.089254920@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 1e53d3626c7802c36419719f772e55ef1a25ebda..8a56f3278b1b95896274849644ef3b2bbaecd557 100644 (file)
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -227,8 +227,8 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
  * defined tracepoints are used. It is discarded after the build.
  */
 # define TRACEPOINT_CHECK(name)                                                \
-       static const char __used __section("__tracepoint_check") __trace_check[] = \
-               #name;
+       static const char __used __section("__tracepoint_check")        \
+       __trace_check_##name[] = #name;
 
 /*
  * Make sure the alignment of the structure in the __tracepoints section will
@@ -382,10 +382,12 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
        __DEFINE_TRACE_EXT(_name, NULL, PARAMS(_proto), PARAMS(_args));
 
 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)                             \
+       TRACEPOINT_CHECK(name)                                          \
        EXPORT_SYMBOL_GPL(__tracepoint_##name);                         \
        EXPORT_SYMBOL_GPL(__traceiter_##name);                          \
        EXPORT_STATIC_CALL_GPL(tp_func_##name)
 #define EXPORT_TRACEPOINT_SYMBOL(name)                                 \
+       TRACEPOINT_CHECK(name)                                          \
        EXPORT_SYMBOL(__tracepoint_##name);                             \
        EXPORT_SYMBOL(__traceiter_##name);                              \
        EXPORT_STATIC_CALL(tp_func_##name)