tracing: tprobe-events: Support multiple tprobes on the same tracepoint

Allow user to set multiple tracepoint-probe events on the same
tracepoint. After the last tprobe-event is removed, the tracepoint
callback is unregistered.

Link: https://lore.kernel.org/all/174343536245.843280.6548776576601537671.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Author: mhiramat

include/linux/module.h

@@ -14,6 +14,7 @@
 #include <linux/buildid.h>
 #include <linux/compiler.h>
 #include <linux/cache.h>
+#include <linux/cleanup.h>
 #include <linux/kmod.h>
 #include <linux/init.h>
 #include <linux/elf.h>
@@ -1019,4 +1020,7 @@ static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
 
 #endif  /* CONFIG_MODULES && CONFIG_KALLSYMS */
 
+/* Define __free(module_put) macro for struct module *. */
+DEFINE_FREE(module_put, struct module *, if (_T) module_put(_T))
+
 #endif /* _LINUX_MODULE_H */