Re: [PATCH net-next 1/2] devlink: fix build error for CONFIG_MODULES=n

[Jiri Pirko <jiri@resnulli.us>]

Wed, Jul 13, 2016 at 11:03:37PM CEST, arnd@arndb.de wrote:
>A driver calling trace_devlink_hwmsg cannot be built when modules are disabled:
>
>include/trace/events/devlink.h: In function 'trace_event_get_offsets_devlink_hwmsg':
>include/trace/events/devlink.h:25:51: error: dereferencing pointer to incomplete type 'struct module'
>   __string(owner_name, devlink->dev->driver->owner->name)
>
>This changes the code to only print the module name when modules are actually
>enabled, otherwise we hardcode the string "built-in".
>
>Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>Fixes: e5224f0fe2ac ("devlink: add hardware messages tracing facility")
>---
> include/trace/events/devlink.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
>diff --git a/include/trace/events/devlink.h b/include/trace/events/devlink.h
>index 333c32ac9bfa..26f92d3c7e9c 100644
>--- a/include/trace/events/devlink.h
>+++ b/include/trace/events/devlink.h
>@@ -22,7 +22,11 @@ TRACE_EVENT(devlink_hwmsg,
> 	TP_STRUCT__entry(
> 		__string(bus_name, devlink->dev->bus->name)
> 		__string(dev_name, dev_name(devlink->dev))
>+#ifdef CONFIG_MODULES
> 		__string(owner_name, devlink->dev->driver->owner->name)

I think would be better to use driver->name. I looks like it is always
present. I will do some tests and send a patch.


>+#else
>+		__string(owner_name, "built-in")
>+#endif
> 		__field(bool, incoming)
> 		__field(unsigned long, type)
> 		__dynamic_array(u8, buf, len)
>@@ -32,7 +36,11 @@ TRACE_EVENT(devlink_hwmsg,
> 	TP_fast_assign(
> 		__assign_str(bus_name, devlink->dev->bus->name);
> 		__assign_str(dev_name, dev_name(devlink->dev));
>+#ifdef CONFIG_MODULES
> 		__assign_str(owner_name, devlink->dev->driver->owner->name);
>+#else
>+		__assign_str(owner_name, "built-in");
>+#endif
> 		__entry->incoming = incoming;
> 		__entry->type = type;
> 		memcpy(__get_dynamic_array(buf), buf, len);
>-- 
>2.9.0
>