From 2a04b8d846dca196342862caecadd2a78460d8dc Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 12 Jul 2022 18:58:20 -0400 Subject: [PATCH] tracing: devlink: Use static array for string in devlink_trap_report event The trace event devlink_trap_report uses the __dynamic_array() macro to determine the size of the input_dev_name field. This is because it needs to test the dev field for NULL, and will use "NULL" if it is. But it also has the size of the dynamic array as a fixed IFNAMSIZ bytes. This defeats the purpose of the dynamic array, as this will reserve that amount of bytes on the ring buffer, and to make matters worse, it will even save that size in the event as the event expects it to be dynamic (for which it is not). Since IFNAMSIZ is just 16 bytes, just make it a static array and this will remove the meta data from the event that records the size. Link: https://lkml.kernel.org/r/20220712185820.002d9fb5@gandalf.local.home Cc: Leon Romanovsky Cc: Jiri Pirko Cc: "David S. Miller" Cc: Eric Dumazet Cc: Paolo Abeni Cc: netdev@vger.kernel.org Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Acked-by: Jakub Kicinski Signed-off-by: Steven Rostedt (Google) --- include/trace/events/devlink.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/include/trace/events/devlink.h b/include/trace/events/devlink.h index 2814f188d98c3..24969184c5348 100644 --- a/include/trace/events/devlink.h +++ b/include/trace/events/devlink.h @@ -186,7 +186,7 @@ TRACE_EVENT(devlink_trap_report, __string(driver_name, devlink_to_dev(devlink)->driver->name) __string(trap_name, metadata->trap_name) __string(trap_group_name, metadata->trap_group_name) - __dynamic_array(char, input_dev_name, IFNAMSIZ) + __array(char, input_dev_name, IFNAMSIZ) ), TP_fast_assign( @@ -197,15 +197,14 @@ TRACE_EVENT(devlink_trap_report, __assign_str(driver_name, devlink_to_dev(devlink)->driver->name); __assign_str(trap_name, metadata->trap_name); __assign_str(trap_group_name, metadata->trap_group_name); - __assign_str(input_dev_name, - (input_dev ? input_dev->name : "NULL")); + strscpy(__entry->input_dev_name, input_dev ? input_dev->name : "NULL", IFNAMSIZ); ), TP_printk("bus_name=%s dev_name=%s driver_name=%s trap_name=%s " "trap_group_name=%s input_dev_name=%s", __get_str(bus_name), __get_str(dev_name), __get_str(driver_name), __get_str(trap_name), __get_str(trap_group_name), - __get_str(input_dev_name)) + __entry->input_dev_name) ); #endif /* _TRACE_DEVLINK_H */