Format fields of a syscall have the first variable '__syscall_nr' or 'nr' that mean the syscall number. But it isn't relevant here so drop it.
'nr' among fields of syscall was renamed '__syscall_nr'. So add exception handling to drop '__syscall_nr' and modify the comment for this excpetion handling. Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Steven Rostedt <[email protected]> Signed-off-by: Taeung Song <[email protected]> --- tools/perf/builtin-trace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 20916dd..a252f3a 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1724,8 +1724,12 @@ static int trace__read_syscall_info(struct trace *trace, int id) sc->args = sc->tp_format->format.fields; sc->nr_args = sc->tp_format->format.nr_fields; - /* drop nr field - not relevant here; does not exist on older kernels */ - if (sc->args && strcmp(sc->args->name, "nr") == 0) { + /* + * We need to check and discard the first variable '__syscall_nr' + * or 'nr' that mean the syscall number. It is needless here. + * So drop '__syscall_nr' or 'nr' field but does not exist on older kernels. + */ + if (sc->args && (!strcmp(sc->args->name, "__syscall_nr") || !strcmp(sc->args->name, "nr"))) { sc->args = sc->args->next; --sc->nr_args; } -- 2.5.0
