selftests/bpf: Test for syscall program type

bpf_prog_type_syscall is a program that creates a bpf map,
updates it, and loads another bpf program using bpf_sys_bpf() helper.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-6-alexei.starovoitov@gmail.com

diff --git a/tools/testing/selftests/bpf/prog_tests/syscall.c b/tools/testing/selftests/bpf/prog_tests/syscall.c
new file mode 100644 (file)
index 0000000..1badd37
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/syscall.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <test_progs.h>
+#include "syscall.skel.h"
+
+struct args {
+       __u64 log_buf;
+       __u32 log_size;
+       int max_entries;
+       int map_fd;
+       int prog_fd;
+};
+
+void test_syscall(void)
+{
+       static char verifier_log[8192];
+       struct args ctx = {
+               .max_entries = 1024,
+               .log_buf = (uintptr_t) verifier_log,
+               .log_size = sizeof(verifier_log),
+       };
+       struct bpf_prog_test_run_attr tattr = {
+               .ctx_in = &ctx,
+               .ctx_size_in = sizeof(ctx),
+       };
+       struct syscall *skel = NULL;
+       __u64 key = 12, value = 0;
+       int err;
+
+       skel = syscall__open_and_load();
+       if (!ASSERT_OK_PTR(skel, "skel_load"))
+               goto cleanup;
+
+       tattr.prog_fd = bpf_program__fd(skel->progs.bpf_prog);
+       err = bpf_prog_test_run_xattr(&tattr);
+       ASSERT_EQ(err, 0, "err");
+       ASSERT_EQ(tattr.retval, 1, "retval");
+       ASSERT_GT(ctx.map_fd, 0, "ctx.map_fd");
+       ASSERT_GT(ctx.prog_fd, 0, "ctx.prog_fd");
+       ASSERT_OK(memcmp(verifier_log, "processed", sizeof("processed") - 1),
+                 "verifier_log");
+
+       err = bpf_map_lookup_elem(ctx.map_fd, &key, &value);
+       ASSERT_EQ(err, 0, "map_lookup");
+       ASSERT_EQ(value, 34, "map lookup value");
+cleanup:
+       syscall__destroy(skel);
+       if (ctx.prog_fd > 0)
+               close(ctx.prog_fd);
+       if (ctx.map_fd > 0)
+               close(ctx.map_fd);
+}

diff --git a/tools/testing/selftests/bpf/progs/syscall.c b/tools/testing/selftests/bpf/progs/syscall.c
new file mode 100644 (file)
index 0000000..865b526
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/syscall.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <linux/stddef.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <../../../tools/include/linux/filter.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct args {
+       __u64 log_buf;
+       __u32 log_size;
+       int max_entries;
+       int map_fd;
+       int prog_fd;
+};
+
+SEC("syscall")
+int bpf_prog(struct args *ctx)
+{
+       static char license[] = "GPL";
+       static struct bpf_insn insns[] = {
+               BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+               BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+               BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+               BPF_LD_MAP_FD(BPF_REG_1, 0),
+               BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+               BPF_MOV64_IMM(BPF_REG_0, 0),
+               BPF_EXIT_INSN(),
+       };
+       static union bpf_attr map_create_attr = {
+               .map_type = BPF_MAP_TYPE_HASH,
+               .key_size = 8,
+               .value_size = 8,
+       };
+       static union bpf_attr map_update_attr = { .map_fd = 1, };
+       static __u64 key = 12;
+       static __u64 value = 34;
+       static union bpf_attr prog_load_attr = {
+               .prog_type = BPF_PROG_TYPE_XDP,
+               .insn_cnt = sizeof(insns) / sizeof(insns[0]),
+       };
+       int ret;
+
+       map_create_attr.max_entries = ctx->max_entries;
+       prog_load_attr.license = (long) license;
+       prog_load_attr.insns = (long) insns;
+       prog_load_attr.log_buf = ctx->log_buf;
+       prog_load_attr.log_size = ctx->log_size;
+       prog_load_attr.log_level = 1;
+
+       ret = bpf_sys_bpf(BPF_MAP_CREATE, &map_create_attr, sizeof(map_create_attr));
+       if (ret <= 0)
+               return ret;
+       ctx->map_fd = ret;
+       insns[3].imm = ret;
+
+       map_update_attr.map_fd = ret;
+       map_update_attr.key = (long) &key;
+       map_update_attr.value = (long) &value;
+       ret = bpf_sys_bpf(BPF_MAP_UPDATE_ELEM, &map_update_attr, sizeof(map_update_attr));
+       if (ret < 0)
+               return ret;
+
+       ret = bpf_sys_bpf(BPF_PROG_LOAD, &prog_load_attr, sizeof(prog_load_attr));
+       if (ret <= 0)
+               return ret;
+       ctx->prog_fd = ret;
+       return 1;
+}