neighbor: tracing: Move pin6 inside CONFIG_IPV6=y section

When CONFIG_IPV6=n, and building with W=1:

    In file included from include/trace/define_trace.h:102,
		     from include/trace/events/neigh.h:255,
		     from net/core/net-traces.c:51:
    include/trace/events/neigh.h: In function ‘trace_event_raw_event_neigh_create’:
    include/trace/events/neigh.h:42:34: error: variable ‘pin6’ set but not used [-Werror=unused-but-set-variable]
       42 |                 struct in6_addr *pin6;
	  |                                  ^~~~
    include/trace/trace_events.h:402:11: note: in definition of macro ‘DECLARE_EVENT_CLASS’
      402 |         { assign; }                                                     \
	  |           ^~~~~~
    include/trace/trace_events.h:44:30: note: in expansion of macro ‘PARAMS’
       44 |                              PARAMS(assign),                   \
	  |                              ^~~~~~
    include/trace/events/neigh.h:23:1: note: in expansion of macro ‘TRACE_EVENT’
       23 | TRACE_EVENT(neigh_create,
	  | ^~~~~~~~~~~
    include/trace/events/neigh.h:41:9: note: in expansion of macro ‘TP_fast_assign’
       41 |         TP_fast_assign(
	  |         ^~~~~~~~~~~~~~
    In file included from include/trace/define_trace.h:103,
		     from include/trace/events/neigh.h:255,
		     from net/core/net-traces.c:51:
    include/trace/events/neigh.h: In function ‘perf_trace_neigh_create’:
    include/trace/events/neigh.h:42:34: error: variable ‘pin6’ set but not used [-Werror=unused-but-set-variable]
       42 |                 struct in6_addr *pin6;
	  |                                  ^~~~
    include/trace/perf.h:51:11: note: in definition of macro ‘DECLARE_EVENT_CLASS’
       51 |         { assign; }                                                     \
	  |           ^~~~~~
    include/trace/trace_events.h:44:30: note: in expansion of macro ‘PARAMS’
       44 |                              PARAMS(assign),                   \
	  |                              ^~~~~~
    include/trace/events/neigh.h:23:1: note: in expansion of macro ‘TRACE_EVENT’
       23 | TRACE_EVENT(neigh_create,
	  | ^~~~~~~~~~~
    include/trace/events/neigh.h:41:9: note: in expansion of macro ‘TP_fast_assign’
       41 |         TP_fast_assign(
	  |         ^~~~~~~~~~~~~~

Indeed, the variable pin6 is declared and initialized unconditionally,
while it is only used and needlessly re-initialized when support for
IPv6 is enabled.

Fix this by dropping the unused variable initialization, and moving the
variable declaration inside the existing section protected by a check
for CONFIG_IPV6.

Fixes: fc651001d2c5ca4f ("neighbor: Add tracepoint to __neigh_create")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Simon Horman <horms@kernel.org> # build-tested
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/trace/events/neigh.h b/include/trace/events/neigh.h
index 5eaa1fa9917153f6038d82ce5474d1f9acc6a0fa..833143d0992e063bc80e06ac3b0e94fdd263460b 100644 (file)
--- a/include/trace/events/neigh.h
+++ b/include/trace/events/neigh.h
@@ -39,7 +39,6 @@ TRACE_EVENT(neigh_create,
        ),
 
        TP_fast_assign(
-               struct in6_addr *pin6;
                __be32 *p32;
 
                __entry->family = tbl->family;
@@ -47,7 +46,6 @@ TRACE_EVENT(neigh_create,
                __entry->entries = atomic_read(&tbl->gc_entries);
                __entry->created = n != NULL;
                __entry->gc_exempt = exempt_from_gc;
-               pin6 = (struct in6_addr *)__entry->primary_key6;
                p32 = (__be32 *)__entry->primary_key4;
 
                if (tbl->family == AF_INET)
@@ -57,6 +55,8 @@ TRACE_EVENT(neigh_create,
 
 #if IS_ENABLED(CONFIG_IPV6)
                if (tbl->family == AF_INET6) {
+                       struct in6_addr *pin6;
+
                        pin6 = (struct in6_addr *)__entry->primary_key6;
                        *pin6 = *(struct in6_addr *)pkey;
                }