From: Zheng Yejian zhengyejian1@huawei.com
The maximum number of synthetic fields supported is defined as SYNTH_FIELDS_MAX which value currently is 64, but it actually fails when try to generate a synthetic event with 64 fields by executing like:
# echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\ int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\ int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\ int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\ int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\ int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\ int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\ int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\ int v63; int v64" >> /sys/kernel/tracing/synthetic_events
Correct the field counting to fix it.
Link: https://lore.kernel.org/linux-trace-kernel/20221207091557.3137904-1-zhengyej...
Cc: mhiramat@kernel.org Cc: zanussi@kernel.org Cc: stable@vger.kernel.org Fixes: c9e759b1e845 ("tracing: Rework synthetic event command parsing") Signed-off-by: Zheng Yejian zhengyejian1@huawei.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- kernel/trace/trace_events_synth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index c3b582d19b62..67592eed0be8 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1282,12 +1282,12 @@ static int __create_synth_event(const char *name, const char *raw_fields) goto err_free_arg; }
- fields[n_fields++] = field; if (n_fields == SYNTH_FIELDS_MAX) { synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); ret = -EINVAL; goto err_free_arg; } + fields[n_fields++] = field;
n_fields_this_loop++; }