tracing: Simplify calculating entry size using struct_size()

When tracing a dynamic string field for a synthetic event, the offset
calculation for where to write the next event can use struct_size() to
find what the current size of the structure is.

This simplifies the code and makes it less error prone.

Link: https://lkml.kernel.org/r/20230117152235.698632147@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Ching-lin Yu <chinglinyu@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Google) 2023-01-17 10:21:26 -05:00
parent 3e4272b995
commit 19ff804964

View File

@ -416,8 +416,7 @@ static unsigned int trace_string(struct synth_trace_event *entry,
if (is_dynamic) {
u32 data_offset;
data_offset = offsetof(typeof(*entry), fields);
data_offset += event->n_u64 * sizeof(u64);
data_offset = struct_size(entry, fields, event->n_u64);
data_offset += data_size;
len = kern_fetch_store_strlen((unsigned long)str_val);