From e4700f62dc830184f114378fb5c2bfbe6a4a96cb Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Mon, 21 Nov 2022 07:52:34 +0000 Subject: [PATCH] perf trace: Return error if a system call doesn't exist [ Upstream commit d4223e1776c30b2ce8d0e6eaadcbf696e60fca3c ] 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: b8b1033fcaa091d8 ("perf trace: Mark syscall ids that are not allocated to avoid unnecessary error messages") Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: bpf@vger.kernel.org Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221121075237.127706-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- 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 2bf2119..aaa465d 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1782,11 +1782,11 @@ 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; -- 2.7.4