selftests/bpf: Convert glob_match() to bpf arena

Increase arena test coverage.
Convert glob_match() to bpf arena in two steps:
1.
Copy paste lib/glob.c into bpf_arena_strsearch.h
Copy paste lib/globtests.c into progs/arena_strsearch.c

2.
Add __arena to pointers
Add __arg_arena to global functions that accept arena pointers
Add cond_break to loops

The test also serves as a good example of what's possible
with bpf arena and how existing algorithms can be converted.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20251111032931.21430-1-alexei.starovoitov@gmail.com

1 files changed, 30 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/arena_strsearch.c b/tools/testing/selftests/bpf/prog_tests/arena_strsearch.c
new file mode 100644
index 000000000000..f81a0c066505
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/arena_strsearch.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
+#include <test_progs.h>
+#include "arena_strsearch.skel.h"
+
+static void test_arena_str(void)
+{
+	LIBBPF_OPTS(bpf_test_run_opts, opts);
+	struct arena_strsearch *skel;
+	int ret;
+
+	skel = arena_strsearch__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "arena_strsearch__open_and_load"))
+		return;
+
+	ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.arena_strsearch), &opts);
+	ASSERT_OK(ret, "ret_add");
+	ASSERT_OK(opts.retval, "retval");
+	if (skel->bss->skip) {
+		printf("%s:SKIP:compiler doesn't support arena_cast\n", __func__);
+		test__skip();
+	}
+	arena_strsearch__destroy(skel);
+}
+
+void test_arena_strsearch(void)
+{
+	if (test__start_subtest("arena_strsearch"))
+		test_arena_str();
+}