Here we add support for testing the attach and detach of a BPF program to a tracepoint through tracefs.
Signed-off-by: Joel Fernandes (Google) joel@joelfernandes.org --- .../raw_tp_writable_test_ftrace_run.c | 89 +++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/raw_tp_writable_test_ftrace_run.c
diff --git a/tools/testing/selftests/bpf/prog_tests/raw_tp_writable_test_ftrace_run.c b/tools/testing/selftests/bpf/prog_tests/raw_tp_writable_test_ftrace_run.c new file mode 100644 index 000000000000..7b42e3a69b71 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/raw_tp_writable_test_ftrace_run.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <test_progs.h> +#include <linux/nbd.h> + +void test_raw_tp_writable_test_ftrace_run(void) +{ + __u32 duration = 0; + char error[4096]; + int ret; + + const struct bpf_insn trace_program[] = { + BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, 0), + BPF_MOV64_IMM(BPF_REG_0, 42), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_0, 0), + BPF_EXIT_INSN(), + }; + + struct bpf_load_program_attr load_attr = { + .prog_type = BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, + .license = "GPL v2", + .insns = trace_program, + .insns_cnt = sizeof(trace_program) / sizeof(struct bpf_insn), + .log_level = 2, + }; + + int bpf_fd = bpf_load_program_xattr(&load_attr, error, sizeof(error)); + + if (CHECK(bpf_fd < 0, "bpf_raw_tracepoint_writable loaded", + "failed: %d errno %d\n", bpf_fd, errno)) + return; + + 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 v2", + .insns = skb_program, + .insns_cnt = sizeof(skb_program) / sizeof(struct bpf_insn), + }; + + int 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_bpffd; + + ret = bpf_raw_tracepoint_ftrace_attach("bpf_test_run", + "bpf_test_finish", + bpf_fd); + if (CHECK(ret < 0, "bpf_raw_tracepoint_ftrace_attach", + "failed: %d errno %d\n", ret, errno)) + goto out_filterfd; + + char test_skb[128] = { + 0, + }; + + __u32 prog_ret; + int err = bpf_prog_test_run(filter_fd, 1, test_skb, sizeof(test_skb), 0, + 0, &prog_ret, 0); + CHECK(err != 42, "test_run", + "tracepoint did not modify return value\n"); + CHECK(prog_ret != 0, "test_run_ret", + "socket_filter did not return 0\n"); + + ret = bpf_raw_tracepoint_ftrace_detach("bpf_test_run", + "bpf_test_finish", + bpf_fd); + if (CHECK(ret < 0, "bpf_raw_tracepoint_ftrace_detach", + "failed: %d errno %d\n", ret, errno)) + goto out_filterfd; + + err = bpf_prog_test_run(filter_fd, 1, test_skb, sizeof(test_skb), 0, 0, + &prog_ret, 0); + CHECK(err != 0, "test_run_notrace", + "test_run failed with %d errno %d\n", err, errno); + CHECK(prog_ret != 0, "test_run_ret_notrace", + "socket_filter did not return 0\n"); + +out_filterfd: + close(filter_fd); +out_bpffd: + close(bpf_fd); +}