Commit 6956ea9f authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
Browse files

tracing: Add a helper function to handle the dereference arg in verifier 

Add a helper function called handle_dereference_arg() to replace the logic
that is identical in two locations of test_event_printk().

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250507191703.5dd8a61d@gandalf.local.home


Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent f75340d7

kernel/trace/trace_events.c

+20 −10
Original line number Diff line number Diff line
@@ -400,6 +400,20 @@ static bool process_string(const char *fmt, int len, struct trace_event_call *ca 
	return true;

}



static void handle_dereference_arg(const char *arg_str, u64 string_flags, int len,

				   u64 *dereference_flags, int arg,

				   struct trace_event_call *call)

{

	if (string_flags & (1ULL << arg)) {

		if (process_string(arg_str, len, call))

			*dereference_flags &= ~(1ULL << arg);

	} else if (process_pointer(arg_str, len, call))

		*dereference_flags &= ~(1ULL << arg);

	else

		pr_warn("TRACE EVENT ERROR: Bad dereference argument: '%.*s'\n",

			len, arg_str);

}



/*

 * Examine the print fmt of the event looking for unsafe dereference

 * pointers using %p* that could be recorded in the trace event and
@@ -563,11 +577,9 @@ static void test_event_printk(struct trace_event_call *call) 
			}



			if (dereference_flags & (1ULL << arg)) {

				if (string_flags & (1ULL << arg)) {

					if (process_string(fmt + start_arg, e - start_arg, call))

						dereference_flags &= ~(1ULL << arg);

				} else if (process_pointer(fmt + start_arg, e - start_arg, call))

					dereference_flags &= ~(1ULL << arg);

				handle_dereference_arg(fmt + start_arg, string_flags,

						       e - start_arg,

						       &dereference_flags, arg, call);

			}



			start_arg = i;
@@ -578,11 +590,9 @@ static void test_event_printk(struct trace_event_call *call) 
	}



	if (dereference_flags & (1ULL << arg)) {

		if (string_flags & (1ULL << arg)) {

			if (process_string(fmt + start_arg, i - start_arg, call))

				dereference_flags &= ~(1ULL << arg);

		} else if (process_pointer(fmt + start_arg, i - start_arg, call))

			dereference_flags &= ~(1ULL << arg);

		handle_dereference_arg(fmt + start_arg, string_flags,

				       i - start_arg,

				       &dereference_flags, arg, call);

	}



	/*