selftests/bpf: Add stress test for maximum number of progs

Add stress test for maximum number of attached BPF programs per BPF trampoline.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-13-ast@kernel.org

diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_stress.c b/tools/testing/selftests/bpf/prog_tests/fexit_stress.c
new file mode 100644 (file)
index 0000000..3b9dbf7
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_stress.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook */
+#include <test_progs.h>
+
+/* x86-64 fits 55 JITed and 43 interpreted progs into half page */
+#define CNT 40
+
+void test_fexit_stress(void)
+{
+       char test_skb[128] = {};
+       int fexit_fd[CNT] = {};
+       int link_fd[CNT] = {};
+       __u32 duration = 0;
+       char error[4096];
+       __u32 prog_ret;
+       int err, i, filter_fd;
+
+       const struct bpf_insn trace_program[] = {
+               BPF_MOV64_IMM(BPF_REG_0, 0),
+               BPF_EXIT_INSN(),
+       };
+
+       struct bpf_load_program_attr load_attr = {
+               .prog_type = BPF_PROG_TYPE_TRACING,
+               .license = "GPL",
+               .insns = trace_program,
+               .insns_cnt = sizeof(trace_program) / sizeof(struct bpf_insn),
+               .expected_attach_type = BPF_TRACE_FEXIT,
+       };
+
+       const struct bpf_insn skb_program[] = {
+               BPF_MOV64_IMM(BPF_REG_0, 0),
+               BPF_EXIT_INSN(),
+       };
+
+       struct bpf_load_program_attr skb_load_attr = {
+               .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
+               .license = "GPL",
+               .insns = skb_program,
+               .insns_cnt = sizeof(skb_program) / sizeof(struct bpf_insn),
+       };
+
+       err = libbpf_find_vmlinux_btf_id("bpf_fentry_test1",
+                                        load_attr.expected_attach_type);
+       if (CHECK(err <= 0, "find_vmlinux_btf_id", "failed: %d\n", err))
+               goto out;
+       load_attr.attach_btf_id = err;
+
+       for (i = 0; i < CNT; i++) {
+               fexit_fd[i] = bpf_load_program_xattr(&load_attr, error, sizeof(error));
+               if (CHECK(fexit_fd[i] < 0, "fexit loaded",
+                         "failed: %d errno %d\n", fexit_fd[i], errno))
+                       goto out;
+               link_fd[i] = bpf_raw_tracepoint_open(NULL, fexit_fd[i]);
+               if (CHECK(link_fd[i] < 0, "fexit attach failed",
+                         "prog %d failed: %d err %d\n", i, link_fd[i], errno))
+                       goto out;
+       }
+
+       filter_fd = bpf_load_program_xattr(&skb_load_attr, error, sizeof(error));
+       if (CHECK(filter_fd < 0, "test_program_loaded", "failed: %d errno %d\n",
+                 filter_fd, errno))
+               goto out;
+
+       err = bpf_prog_test_run(filter_fd, 1, test_skb, sizeof(test_skb), 0,
+                               0, &prog_ret, 0);
+       close(filter_fd);
+       CHECK_FAIL(err);
+out:
+       for (i = 0; i < CNT; i++) {
+               if (link_fd[i])
+                       close(link_fd[i]);
+               if (fexit_fd[i])
+                       close(fexit_fd[i]);
+       }
+}