From 1e8611bbdfc99faf8c9670dbbe582129a9a29973 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 1 Jul 2019 16:59:02 -0700 Subject: [PATCH] selftests/bpf: add kprobe/uprobe selftests Add tests verifying kprobe/kretprobe/uprobe/uretprobe APIs work as expected. Signed-off-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- .../selftests/bpf/prog_tests/attach_probe.c | 166 +++++++++++++++++++++ .../selftests/bpf/progs/test_attach_probe.c | 55 +++++++ 2 files changed, 221 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/attach_probe.c create mode 100644 tools/testing/selftests/bpf/progs/test_attach_probe.c diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c new file mode 100644 index 0000000..a468639 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +ssize_t get_base_addr() { + size_t start; + char buf[256]; + FILE *f; + + f = fopen("/proc/self/maps", "r"); + if (!f) + return -errno; + + while (fscanf(f, "%zx-%*x %s %*s\n", &start, buf) == 2) { + if (strcmp(buf, "r-xp") == 0) { + fclose(f); + return start; + } + } + + fclose(f); + return -EINVAL; +} + +#ifdef __x86_64__ +#define SYS_KPROBE_NAME "__x64_sys_nanosleep" +#else +#define SYS_KPROBE_NAME "sys_nanosleep" +#endif + +void test_attach_probe(void) +{ + const char *kprobe_name = "kprobe/sys_nanosleep"; + const char *kretprobe_name = "kretprobe/sys_nanosleep"; + const char *uprobe_name = "uprobe/trigger_func"; + const char *uretprobe_name = "uretprobe/trigger_func"; + const int kprobe_idx = 0, kretprobe_idx = 1; + const int uprobe_idx = 2, uretprobe_idx = 3; + const char *file = "./test_attach_probe.o"; + struct bpf_program *kprobe_prog, *kretprobe_prog; + struct bpf_program *uprobe_prog, *uretprobe_prog; + struct bpf_object *obj; + int err, prog_fd, duration = 0, res; + struct bpf_link *kprobe_link = NULL; + struct bpf_link *kretprobe_link = NULL; + struct bpf_link *uprobe_link = NULL; + struct bpf_link *uretprobe_link = NULL; + int results_map_fd; + size_t uprobe_offset; + ssize_t base_addr; + + base_addr = get_base_addr(); + if (CHECK(base_addr < 0, "get_base_addr", + "failed to find base addr: %zd", base_addr)) + return; + uprobe_offset = (size_t)&get_base_addr - base_addr; + + /* load programs */ + err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd); + if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) + return; + + kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name); + if (CHECK(!kprobe_prog, "find_probe", + "prog '%s' not found\n", kprobe_name)) + goto cleanup; + kretprobe_prog = bpf_object__find_program_by_title(obj, kretprobe_name); + if (CHECK(!kretprobe_prog, "find_probe", + "prog '%s' not found\n", kretprobe_name)) + goto cleanup; + uprobe_prog = bpf_object__find_program_by_title(obj, uprobe_name); + if (CHECK(!uprobe_prog, "find_probe", + "prog '%s' not found\n", uprobe_name)) + goto cleanup; + uretprobe_prog = bpf_object__find_program_by_title(obj, uretprobe_name); + if (CHECK(!uretprobe_prog, "find_probe", + "prog '%s' not found\n", uretprobe_name)) + goto cleanup; + + /* load maps */ + results_map_fd = bpf_find_map(__func__, obj, "results_map"); + if (CHECK(results_map_fd < 0, "find_results_map", + "err %d\n", results_map_fd)) + goto cleanup; + + kprobe_link = bpf_program__attach_kprobe(kprobe_prog, + false /* retprobe */, + SYS_KPROBE_NAME); + if (CHECK(IS_ERR(kprobe_link), "attach_kprobe", + "err %ld\n", PTR_ERR(kprobe_link))) { + kprobe_link = NULL; + goto cleanup; + } + kretprobe_link = bpf_program__attach_kprobe(kretprobe_prog, + true /* retprobe */, + SYS_KPROBE_NAME); + if (CHECK(IS_ERR(kretprobe_link), "attach_kretprobe", + "err %ld\n", PTR_ERR(kretprobe_link))) { + kretprobe_link = NULL; + goto cleanup; + } + uprobe_link = bpf_program__attach_uprobe(uprobe_prog, + false /* retprobe */, + 0 /* self pid */, + "/proc/self/exe", + uprobe_offset); + if (CHECK(IS_ERR(uprobe_link), "attach_uprobe", + "err %ld\n", PTR_ERR(uprobe_link))) { + uprobe_link = NULL; + goto cleanup; + } + uretprobe_link = bpf_program__attach_uprobe(uretprobe_prog, + true /* retprobe */, + -1 /* any pid */, + "/proc/self/exe", + uprobe_offset); + if (CHECK(IS_ERR(uretprobe_link), "attach_uretprobe", + "err %ld\n", PTR_ERR(uretprobe_link))) { + uretprobe_link = NULL; + goto cleanup; + } + + /* trigger & validate kprobe && kretprobe */ + usleep(1); + + err = bpf_map_lookup_elem(results_map_fd, &kprobe_idx, &res); + if (CHECK(err, "get_kprobe_res", + "failed to get kprobe res: %d\n", err)) + goto cleanup; + if (CHECK(res != kprobe_idx + 1, "check_kprobe_res", + "wrong kprobe res: %d\n", res)) + goto cleanup; + + err = bpf_map_lookup_elem(results_map_fd, &kretprobe_idx, &res); + if (CHECK(err, "get_kretprobe_res", + "failed to get kretprobe res: %d\n", err)) + goto cleanup; + if (CHECK(res != kretprobe_idx + 1, "check_kretprobe_res", + "wrong kretprobe res: %d\n", res)) + goto cleanup; + + /* trigger & validate uprobe & uretprobe */ + get_base_addr(); + + err = bpf_map_lookup_elem(results_map_fd, &uprobe_idx, &res); + if (CHECK(err, "get_uprobe_res", + "failed to get uprobe res: %d\n", err)) + goto cleanup; + if (CHECK(res != uprobe_idx + 1, "check_uprobe_res", + "wrong uprobe res: %d\n", res)) + goto cleanup; + + err = bpf_map_lookup_elem(results_map_fd, &uretprobe_idx, &res); + if (CHECK(err, "get_uretprobe_res", + "failed to get uretprobe res: %d\n", err)) + goto cleanup; + if (CHECK(res != uretprobe_idx + 1, "check_uretprobe_res", + "wrong uretprobe res: %d\n", res)) + goto cleanup; + +cleanup: + bpf_link__destroy(kprobe_link); + bpf_link__destroy(kretprobe_link); + bpf_link__destroy(uprobe_link); + bpf_link__destroy(uretprobe_link); + bpf_object__close(obj); +} diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c new file mode 100644 index 0000000..7a7c5cd --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2017 Facebook + +#include +#include +#include "bpf_helpers.h" + +struct { + int type; + int max_entries; + int *key; + int *value; +} results_map SEC(".maps") = { + .type = BPF_MAP_TYPE_ARRAY, + .max_entries = 4, +}; + +SEC("kprobe/sys_nanosleep") +int handle_sys_nanosleep_entry(struct pt_regs *ctx) +{ + const int key = 0, value = 1; + + bpf_map_update_elem(&results_map, &key, &value, 0); + return 0; +} + +SEC("kretprobe/sys_nanosleep") +int handle_sys_getpid_return(struct pt_regs *ctx) +{ + const int key = 1, value = 2; + + bpf_map_update_elem(&results_map, &key, &value, 0); + return 0; +} + +SEC("uprobe/trigger_func") +int handle_uprobe_entry(struct pt_regs *ctx) +{ + const int key = 2, value = 3; + + bpf_map_update_elem(&results_map, &key, &value, 0); + return 0; +} + +SEC("uretprobe/trigger_func") +int handle_uprobe_return(struct pt_regs *ctx) +{ + const int key = 3, value = 4; + + bpf_map_update_elem(&results_map, &key, &value, 0); + return 0; +} + +char _license[] SEC("license") = "GPL"; +__u32 _version SEC("version") = 1; -- 2.7.4