[PATCH] tools/sched_ext: fix getopt not re-parsed on restart

[David Carlier <devnexen@gmail.com>]

After goto restart, optind retains its advanced position from the
previous getopt loop, causing getopt() to immediately return -1.
This silently drops all command-line options on the restarted skeleton.

Reset optind to 1 at the restart label so options are re-parsed.

Affected schedulers: scx_simple, scx_central, scx_flatcg, scx_pair,
scx_sdt, scx_cpu0.

Signed-off-by: David Carlier <devnexen@gmail.com>
---
 tools/sched_ext/scx_central.c | 1 +
 tools/sched_ext/scx_cpu0.c    | 1 +
 tools/sched_ext/scx_flatcg.c  | 1 +
 tools/sched_ext/scx_pair.c    | 1 +
 tools/sched_ext/scx_sdt.c     | 1 +
 tools/sched_ext/scx_simple.c  | 1 +
 6 files changed, 6 insertions(+)

diff --git a/tools/sched_ext/scx_central.c b/tools/sched_ext/scx_central.c
index 39f21b00a208..2a805f1d6c8f 100644
--- a/tools/sched_ext/scx_central.c
+++ b/tools/sched_ext/scx_central.c
@@ -56,6 +56,7 @@ int main(int argc, char **argv)
 	signal(SIGINT, sigint_handler);
 	signal(SIGTERM, sigint_handler);
 restart:
+	optind = 1;
 	skel = SCX_OPS_OPEN(central_ops, scx_central);
 
 	skel->rodata->central_cpu = 0;
diff --git a/tools/sched_ext/scx_cpu0.c b/tools/sched_ext/scx_cpu0.c
index 1e4fa4ab8da9..a6fba9978b9c 100644
--- a/tools/sched_ext/scx_cpu0.c
+++ b/tools/sched_ext/scx_cpu0.c
@@ -69,6 +69,7 @@ int main(int argc, char **argv)
 	signal(SIGINT, sigint_handler);
 	signal(SIGTERM, sigint_handler);
 restart:
+	optind = 1;
 	skel = SCX_OPS_OPEN(cpu0_ops, scx_cpu0);
 
 	skel->rodata->nr_cpus = libbpf_num_possible_cpus();
diff --git a/tools/sched_ext/scx_flatcg.c b/tools/sched_ext/scx_flatcg.c
index a8446509949e..d865c381589b 100644
--- a/tools/sched_ext/scx_flatcg.c
+++ b/tools/sched_ext/scx_flatcg.c
@@ -141,6 +141,7 @@ int main(int argc, char **argv)
 	signal(SIGINT, sigint_handler);
 	signal(SIGTERM, sigint_handler);
 restart:
+	optind = 1;
 	skel = SCX_OPS_OPEN(flatcg_ops, scx_flatcg);
 
 	skel->rodata->nr_cpus = libbpf_num_possible_cpus();
diff --git a/tools/sched_ext/scx_pair.c b/tools/sched_ext/scx_pair.c
index 2a82d8a8a0aa..2e509391f3da 100644
--- a/tools/sched_ext/scx_pair.c
+++ b/tools/sched_ext/scx_pair.c
@@ -53,6 +53,7 @@ int main(int argc, char **argv)
 	signal(SIGINT, sigint_handler);
 	signal(SIGTERM, sigint_handler);
 restart:
+	optind = 1;
 	skel = SCX_OPS_OPEN(pair_ops, scx_pair);
 
 	skel->rodata->nr_cpu_ids = libbpf_num_possible_cpus();
diff --git a/tools/sched_ext/scx_sdt.c b/tools/sched_ext/scx_sdt.c
index b0363363476d..d8ca9aa316a5 100644
--- a/tools/sched_ext/scx_sdt.c
+++ b/tools/sched_ext/scx_sdt.c
@@ -51,6 +51,7 @@ int main(int argc, char **argv)
 	signal(SIGINT, sigint_handler);
 	signal(SIGTERM, sigint_handler);
 restart:
+	optind = 1;
 	skel = SCX_OPS_OPEN(sdt_ops, scx_sdt);
 
 	while ((opt = getopt(argc, argv, "fvh")) != -1) {
diff --git a/tools/sched_ext/scx_simple.c b/tools/sched_ext/scx_simple.c
index 06d4b13bf76b..c3b48611712b 100644
--- a/tools/sched_ext/scx_simple.c
+++ b/tools/sched_ext/scx_simple.c
@@ -71,6 +71,7 @@ int main(int argc, char **argv)
 	signal(SIGINT, sigint_handler);
 	signal(SIGTERM, sigint_handler);
 restart:
+	optind = 1;
 	skel = SCX_OPS_OPEN(simple_ops, scx_simple);
 
 	while ((opt = getopt(argc, argv, "fvh")) != -1) {
-- 
2.51.0