With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.

This means that with:

  __string(field, mystring)

Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.

There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:

  git grep -l __assign_str | while read a ; do
      sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
      mv /tmp/test-file $a;
  done

I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.

Note, the same updates will need to be done for:

  __assign_str_len()
  __assign_rel_str()
  __assign_rel_str_len()

I tested this with both an allmodconfig and an allyesconfig (build only for both).

[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/

Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>	# xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>

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>

The dev field of the neigh_create event uses __dynamic_array() with a
fixed size, which defeats the purpose of __dynamic_array(). Looking at the
logic, as it already uses __assign_str(), just use the same logic in
__string to create the size needed. It appears that because "dev" can be
NULL, it needs the check. But __string() can have the same checks as
__assign_str() so use them there too.

Link: https://lkml.kernel.org/r/20220705183741.35387e3f@rorschach.local.home

Cc: David Ahern <dsahern@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Add tracepoint to __neigh_create to enable debugging of new entries.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Also, extend neigh_state_str to include neigh dummy states
noarp and permanent

Fixes: 9c03b282badb ("trace: events: add a few neigh tracepoints")
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The goal here is to trace neigh state changes covering all possible
neigh update paths. Plus have a specific trace point in neigh_update
to cover flags sent to neigh_update.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>