When a system call is not detected, the reason is either because the system call ID is out of scope or failure to find the corresponding path in the sysfs, trace__read_syscall_info() returns zero. Finally, without returning an error value it introduces confusion for the caller. This patch lets the function trace__read_syscall_info() to return -EEXIST when a system call doesn't exist. Fixes: b8b1033fcaa0 ("perf trace: Mark syscall ids that are not allocated to avoid unnecessary error messages") Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx> --- tools/perf/builtin-trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 22008a31684b..bd5513b15cde 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1796,11 +1796,11 @@ static int trace__read_syscall_info(struct trace *trace, int id) #endif sc = trace->syscalls.table + id; if (sc->nonexistent) - return 0; + return -EEXIST; if (name == NULL) { sc->nonexistent = true; - return 0; + return -EEXIST; } sc->name = name; -- 2.34.1