Commit 70a6ed55 authored by Steven Rostedt (Google)'s avatar Steven Rostedt (Google)
Browse files

tracing: Use EVENT_NULL_STR macro instead of open coding "(null)" 

The TRACE_EVENT macros has some dependency if a __string() field is NULL,
where it will save "(null)" as the string. This string is also used by
__assign_str(). It's better to create a single macro instead of having
something that will not be caught by the compiler if there is an
unfortunate typo.

Link: https://lore.kernel.org/linux-trace-kernel/20240222211443.106216915@goodmis.org



Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Suggested-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 91684986

include/linux/trace_events.h

+3 −0
Original line number Diff line number Diff line
@@ -17,6 +17,9 @@ struct dentry; 
struct bpf_prog;

union bpf_attr;



/* Used for event string fields when they are NULL */

#define EVENT_NULL_STR		"(null)"



const char *trace_print_flags_seq(struct trace_seq *p, const char *delim,

				  unsigned long flags,

				  const struct trace_print_flags *flag_array);

include/trace/events/sunrpc.h

+6 −6
Original line number Diff line number Diff line
@@ -1327,18 +1327,18 @@ TRACE_EVENT(xs_stream_read_data, 
		__field(ssize_t, err)

		__field(size_t, total)

		__string(addr, xprt ? xprt->address_strings[RPC_DISPLAY_ADDR] :

				"(null)")

				EVENT_NULL_STR)

		__string(port, xprt ? xprt->address_strings[RPC_DISPLAY_PORT] :

				"(null)")

				EVENT_NULL_STR)

	),



	TP_fast_assign(

		__entry->err = err;

		__entry->total = total;

		__assign_str(addr, xprt ?

			xprt->address_strings[RPC_DISPLAY_ADDR] : "(null)");

			xprt->address_strings[RPC_DISPLAY_ADDR] : EVENT_NULL_STR);

		__assign_str(port, xprt ?

			xprt->address_strings[RPC_DISPLAY_PORT] : "(null)");

			xprt->address_strings[RPC_DISPLAY_PORT] : EVENT_NULL_STR);

	),



	TP_printk("peer=[%s]:%s err=%zd total=%zu", __get_str(addr),
@@ -1783,7 +1783,7 @@ TRACE_EVENT(svc_process, 
		__string(service, name)

		__string(procedure, svc_proc_name(rqst))

		__string(addr, rqst->rq_xprt ?

			 rqst->rq_xprt->xpt_remotebuf : "(null)")

			 rqst->rq_xprt->xpt_remotebuf : EVENT_NULL_STR)

	),



	TP_fast_assign(
@@ -1793,7 +1793,7 @@ TRACE_EVENT(svc_process, 
		__assign_str(service, name);

		__assign_str(procedure, svc_proc_name(rqst));

		__assign_str(addr, rqst->rq_xprt ?

			     rqst->rq_xprt->xpt_remotebuf : "(null)");

			     rqst->rq_xprt->xpt_remotebuf : EVENT_NULL_STR);

	),



	TP_printk("addr=%s xid=0x%08x service=%s vers=%u proc=%s",

include/trace/stages/stage5_get_offsets.h

+2 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ 


#undef __string

#define __string(item, src) __dynamic_array(char, item,			\

		    strlen((const char *)(src) ? : "(null)") + 1)	\

		    strlen((const char *)(src) ? : EVENT_NULL_STR) + 1)	\

	__data_offsets->item##_ptr_ = src;



#undef __string_len
@@ -70,7 +70,7 @@ 


#undef __rel_string

#define __rel_string(item, src) __rel_dynamic_array(char, item,		\

		    strlen((const char *)(src) ? : "(null)") + 1)	\

		    strlen((const char *)(src) ? : EVENT_NULL_STR) + 1)	\

	__data_offsets->item##_ptr_ = src;



#undef __rel_string_len

include/trace/stages/stage6_event_callback.h

+4 −4
Original line number Diff line number Diff line
@@ -32,14 +32,14 @@ 


#undef __assign_str

#define __assign_str(dst, src)						\

	memcpy(__get_str(dst), __data_offsets.dst##_ptr_ ? : "(null)",	\

	memcpy(__get_str(dst), __data_offsets.dst##_ptr_ ? : EVENT_NULL_STR, \

	       __get_dynamic_array_len(dst))



#undef __assign_str_len

#define __assign_str_len(dst, src, len)					\

	do {								\

		memcpy(__get_str(dst),					\

		       __data_offsets.dst##_ptr_ ? : "(null)", len);	\

		       __data_offsets.dst##_ptr_ ? : EVENT_NULL_STR, len); \

		__get_str(dst)[len] = '\0';				\

	} while(0)
@@ -94,14 +94,14 @@ 


#undef __assign_rel_str

#define __assign_rel_str(dst, src)					\

	memcpy(__get_rel_str(dst), __data_offsets.dst##_ptr_ ? : "(null)", \

	memcpy(__get_rel_str(dst), __data_offsets.dst##_ptr_ ? : EVENT_NULL_STR, \

	       __get_rel_dynamic_array_len(dst))



#undef __assign_rel_str_len

#define __assign_rel_str_len(dst, src, len)				\

	do {								\

		memcpy(__get_rel_str(dst),				\

		       __data_offsets.dst##_ptr_ ? : "(null)", len);	\

		       __data_offsets.dst##_ptr_ ? : EVENT_NULL_STR, len); \

		__get_rel_str(dst)[len] = '\0';				\

	} while (0)