tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL

Catch incorrect use of syscall tracepoints even if no probes are
registered by adding a might_fault() check in trace_##name()
emitted by __DECLARE_TRACE_SYSCALL.

Suggested-by: Thomas Gleixner <[email protected]>
Tested-by: Jordan Rife <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Michael Jeanson <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: [email protected]
Cc: Joel Fernandes <[email protected]>
Cc: Jordan Rife <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Mathieu Desnoyers <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: compudj

include/linux/tracepoint.h

@@ -301,6 +301,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 	__DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
 	static inline void trace_##name(proto)				\
 	{								\
+		might_fault();						\
 		if (static_branch_unlikely(&__tracepoint_##name.key))	\
 			__DO_TRACE(name,				\
 				TP_ARGS(args),				\