5.4-stable review patch. If anyone has any objections, please let me know.
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From: Geert Uytterhoeven geert+renesas@glider.be
commit 2915240eddba96b37de4c7e9a3d0ac6f9548454b upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/trace/events/neigh.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- 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; }