From 23cf7aa539dc26f45e42ef6303613f03f4ae2142 Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sun, 13 Aug 2023 14:19:00 +0000 Subject: [PATCH] selftests/bpf: Add selftest for fill_link_info Add selftest for the fill_link_info of uprobe, kprobe and tracepoint. The result: $ tools/testing/selftests/bpf/test_progs --name=fill_link_info #79/1 fill_link_info/kprobe_link_info:OK #79/2 fill_link_info/kretprobe_link_info:OK #79/3 fill_link_info/kprobe_invalid_ubuff:OK #79/4 fill_link_info/tracepoint_link_info:OK #79/5 fill_link_info/uprobe_link_info:OK #79/6 fill_link_info/uretprobe_link_info:OK #79/7 fill_link_info/kprobe_multi_link_info:OK #79/8 fill_link_info/kretprobe_multi_link_info:OK #79/9 fill_link_info/kprobe_multi_invalid_ubuff:OK #79 fill_link_info:OK Summary: 1/9 PASSED, 0 SKIPPED, 0 FAILED The test case for kprobe_multi won't be run on aarch64, as it is not supported. Signed-off-by: Yafang Shao Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20230813141900.1268-3-laoar.shao@gmail.com --- tools/testing/selftests/bpf/DENYLIST.aarch64 | 3 + .../selftests/bpf/prog_tests/fill_link_info.c | 342 ++++++++++++++++++ .../selftests/bpf/progs/test_fill_link_info.c | 42 +++ 3 files changed, 387 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/fill_link_info.c create mode 100644 tools/testing/selftests/bpf/progs/test_fill_link_info.c diff --git a/tools/testing/selftests/bpf/DENYLIST.aarch64 b/tools/testing/selftests/bpf/DENYLIST.aarch64 index 3b61e8b35d62..7f768d335698 100644 --- a/tools/testing/selftests/bpf/DENYLIST.aarch64 +++ b/tools/testing/selftests/bpf/DENYLIST.aarch64 @@ -12,3 +12,6 @@ kprobe_multi_test/skel_api # libbpf: failed to load BPF sk module_attach # prog 'kprobe_multi': failed to auto-attach: -95 fentry_test/fentry_many_args # fentry_many_args:FAIL:fentry_many_args_attach unexpected error: -524 fexit_test/fexit_many_args # fexit_many_args:FAIL:fexit_many_args_attach unexpected error: -524 +fill_link_info/kprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95 +fill_link_info/kretprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95 +fill_link_info/kprobe_multi_invalid_ubuff # bpf_program__attach_kprobe_multi_opts unexpected error: -95 diff --git a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c new file mode 100644 index 000000000000..9d768e083714 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c @@ -0,0 +1,342 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 Yafang Shao */ + +#include +#include +#include +#include +#include "trace_helpers.h" +#include "test_fill_link_info.skel.h" + +#define TP_CAT "sched" +#define TP_NAME "sched_switch" + +static const char *kmulti_syms[] = { + "bpf_fentry_test2", + "bpf_fentry_test1", + "bpf_fentry_test3", +}; +#define KMULTI_CNT ARRAY_SIZE(kmulti_syms) +static __u64 kmulti_addrs[KMULTI_CNT]; + +#define KPROBE_FUNC "bpf_fentry_test1" +static __u64 kprobe_addr; + +#define UPROBE_FILE "/proc/self/exe" +static ssize_t uprobe_offset; +/* uprobe attach point */ +static noinline void uprobe_func(void) +{ + asm volatile (""); +} + +static int verify_perf_link_info(int fd, enum bpf_perf_event_type type, long addr, + ssize_t offset, ssize_t entry_offset) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + char buf[PATH_MAX]; + int err; + + memset(&info, 0, sizeof(info)); + buf[0] = '\0'; + +again: + err = bpf_link_get_info_by_fd(fd, &info, &len); + if (!ASSERT_OK(err, "get_link_info")) + return -1; + + if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type")) + return -1; + if (!ASSERT_EQ(info.perf_event.type, type, "perf_type_match")) + return -1; + + switch (info.perf_event.type) { + case BPF_PERF_EVENT_KPROBE: + case BPF_PERF_EVENT_KRETPROBE: + ASSERT_EQ(info.perf_event.kprobe.offset, offset, "kprobe_offset"); + + /* In case kernel.kptr_restrict is not permitted or MAX_SYMS is reached */ + if (addr) + ASSERT_EQ(info.perf_event.kprobe.addr, addr + entry_offset, + "kprobe_addr"); + + if (!info.perf_event.kprobe.func_name) { + ASSERT_EQ(info.perf_event.kprobe.name_len, 0, "name_len"); + info.perf_event.kprobe.func_name = ptr_to_u64(&buf); + info.perf_event.kprobe.name_len = sizeof(buf); + goto again; + } + + err = strncmp(u64_to_ptr(info.perf_event.kprobe.func_name), KPROBE_FUNC, + strlen(KPROBE_FUNC)); + ASSERT_EQ(err, 0, "cmp_kprobe_func_name"); + break; + case BPF_PERF_EVENT_TRACEPOINT: + if (!info.perf_event.tracepoint.tp_name) { + ASSERT_EQ(info.perf_event.tracepoint.name_len, 0, "name_len"); + info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf); + info.perf_event.tracepoint.name_len = sizeof(buf); + goto again; + } + + err = strncmp(u64_to_ptr(info.perf_event.tracepoint.tp_name), TP_NAME, + strlen(TP_NAME)); + ASSERT_EQ(err, 0, "cmp_tp_name"); + break; + case BPF_PERF_EVENT_UPROBE: + case BPF_PERF_EVENT_URETPROBE: + ASSERT_EQ(info.perf_event.uprobe.offset, offset, "uprobe_offset"); + + if (!info.perf_event.uprobe.file_name) { + ASSERT_EQ(info.perf_event.uprobe.name_len, 0, "name_len"); + info.perf_event.uprobe.file_name = ptr_to_u64(&buf); + info.perf_event.uprobe.name_len = sizeof(buf); + goto again; + } + + err = strncmp(u64_to_ptr(info.perf_event.uprobe.file_name), UPROBE_FILE, + strlen(UPROBE_FILE)); + ASSERT_EQ(err, 0, "cmp_file_name"); + break; + default: + err = -1; + break; + } + return err; +} + +static void kprobe_fill_invalid_user_buffer(int fd) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + int err; + + memset(&info, 0, sizeof(info)); + + info.perf_event.kprobe.func_name = 0x1; /* invalid address */ + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "invalid_buff_and_len"); + + info.perf_event.kprobe.name_len = 64; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EFAULT, "invalid_buff"); + + info.perf_event.kprobe.func_name = 0; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "invalid_len"); + + ASSERT_EQ(info.perf_event.kprobe.addr, 0, "func_addr"); + ASSERT_EQ(info.perf_event.kprobe.offset, 0, "func_offset"); + ASSERT_EQ(info.perf_event.type, 0, "type"); +} + +static void test_kprobe_fill_link_info(struct test_fill_link_info *skel, + enum bpf_perf_event_type type, + bool invalid) +{ + DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts, + .attach_mode = PROBE_ATTACH_MODE_LINK, + .retprobe = type == BPF_PERF_EVENT_KRETPROBE, + ); + ssize_t entry_offset = 0; + int link_fd, err; + + skel->links.kprobe_run = bpf_program__attach_kprobe_opts(skel->progs.kprobe_run, + KPROBE_FUNC, &opts); + if (!ASSERT_OK_PTR(skel->links.kprobe_run, "attach_kprobe")) + return; + + link_fd = bpf_link__fd(skel->links.kprobe_run); + if (!invalid) { + /* See also arch_adjust_kprobe_addr(). */ + if (skel->kconfig->CONFIG_X86_KERNEL_IBT) + entry_offset = 4; + err = verify_perf_link_info(link_fd, type, kprobe_addr, 0, entry_offset); + ASSERT_OK(err, "verify_perf_link_info"); + } else { + kprobe_fill_invalid_user_buffer(link_fd); + } + bpf_link__detach(skel->links.kprobe_run); +} + +static void test_tp_fill_link_info(struct test_fill_link_info *skel) +{ + int link_fd, err; + + skel->links.tp_run = bpf_program__attach_tracepoint(skel->progs.tp_run, TP_CAT, TP_NAME); + if (!ASSERT_OK_PTR(skel->links.tp_run, "attach_tp")) + return; + + link_fd = bpf_link__fd(skel->links.tp_run); + err = verify_perf_link_info(link_fd, BPF_PERF_EVENT_TRACEPOINT, 0, 0, 0); + ASSERT_OK(err, "verify_perf_link_info"); + bpf_link__detach(skel->links.tp_run); +} + +static void test_uprobe_fill_link_info(struct test_fill_link_info *skel, + enum bpf_perf_event_type type) +{ + int link_fd, err; + + skel->links.uprobe_run = bpf_program__attach_uprobe(skel->progs.uprobe_run, + type == BPF_PERF_EVENT_URETPROBE, + 0, /* self pid */ + UPROBE_FILE, uprobe_offset); + if (!ASSERT_OK_PTR(skel->links.uprobe_run, "attach_uprobe")) + return; + + link_fd = bpf_link__fd(skel->links.uprobe_run); + err = verify_perf_link_info(link_fd, type, 0, uprobe_offset, 0); + ASSERT_OK(err, "verify_perf_link_info"); + bpf_link__detach(skel->links.uprobe_run); +} + +static int verify_kmulti_link_info(int fd, bool retprobe) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + __u64 addrs[KMULTI_CNT]; + int flags, i, err; + + memset(&info, 0, sizeof(info)); + +again: + err = bpf_link_get_info_by_fd(fd, &info, &len); + if (!ASSERT_OK(err, "get_link_info")) + return -1; + + if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_KPROBE_MULTI, "kmulti_type")) + return -1; + + ASSERT_EQ(info.kprobe_multi.count, KMULTI_CNT, "func_cnt"); + flags = info.kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN; + if (!retprobe) + ASSERT_EQ(flags, 0, "kmulti_flags"); + else + ASSERT_NEQ(flags, 0, "kretmulti_flags"); + + if (!info.kprobe_multi.addrs) { + info.kprobe_multi.addrs = ptr_to_u64(addrs); + goto again; + } + for (i = 0; i < KMULTI_CNT; i++) + ASSERT_EQ(addrs[i], kmulti_addrs[i], "kmulti_addrs"); + return 0; +} + +static void verify_kmulti_invalid_user_buffer(int fd) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + __u64 addrs[KMULTI_CNT]; + int err, i; + + memset(&info, 0, sizeof(info)); + + info.kprobe_multi.count = KMULTI_CNT; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "no_addr"); + + info.kprobe_multi.addrs = ptr_to_u64(addrs); + info.kprobe_multi.count = 0; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "no_cnt"); + + for (i = 0; i < KMULTI_CNT; i++) + addrs[i] = 0; + info.kprobe_multi.count = KMULTI_CNT - 1; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -ENOSPC, "smaller_cnt"); + for (i = 0; i < KMULTI_CNT - 1; i++) + ASSERT_EQ(addrs[i], kmulti_addrs[i], "kmulti_addrs"); + ASSERT_EQ(addrs[i], 0, "kmulti_addrs"); + + for (i = 0; i < KMULTI_CNT; i++) + addrs[i] = 0; + info.kprobe_multi.count = KMULTI_CNT + 1; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, 0, "bigger_cnt"); + for (i = 0; i < KMULTI_CNT; i++) + ASSERT_EQ(addrs[i], kmulti_addrs[i], "kmulti_addrs"); + + info.kprobe_multi.count = KMULTI_CNT; + info.kprobe_multi.addrs = 0x1; /* invalid addr */ + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EFAULT, "invalid_buff"); +} + +static int symbols_cmp_r(const void *a, const void *b) +{ + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; + + return strcmp(*str_a, *str_b); +} + +static void test_kprobe_multi_fill_link_info(struct test_fill_link_info *skel, + bool retprobe, bool invalid) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + int link_fd, err; + + opts.syms = kmulti_syms; + opts.cnt = KMULTI_CNT; + opts.retprobe = retprobe; + skel->links.kmulti_run = bpf_program__attach_kprobe_multi_opts(skel->progs.kmulti_run, + NULL, &opts); + if (!ASSERT_OK_PTR(skel->links.kmulti_run, "attach_kprobe_multi")) + return; + + link_fd = bpf_link__fd(skel->links.kmulti_run); + if (!invalid) { + err = verify_kmulti_link_info(link_fd, retprobe); + ASSERT_OK(err, "verify_kmulti_link_info"); + } else { + verify_kmulti_invalid_user_buffer(link_fd); + } + bpf_link__detach(skel->links.kmulti_run); +} + +void test_fill_link_info(void) +{ + struct test_fill_link_info *skel; + int i; + + skel = test_fill_link_info__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + /* load kallsyms to compare the addr */ + if (!ASSERT_OK(load_kallsyms_refresh(), "load_kallsyms_refresh")) + goto cleanup; + + kprobe_addr = ksym_get_addr(KPROBE_FUNC); + if (test__start_subtest("kprobe_link_info")) + test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, false); + if (test__start_subtest("kretprobe_link_info")) + test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KRETPROBE, false); + if (test__start_subtest("kprobe_invalid_ubuff")) + test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, true); + if (test__start_subtest("tracepoint_link_info")) + test_tp_fill_link_info(skel); + + uprobe_offset = get_uprobe_offset(&uprobe_func); + if (test__start_subtest("uprobe_link_info")) + test_uprobe_fill_link_info(skel, BPF_PERF_EVENT_UPROBE); + if (test__start_subtest("uretprobe_link_info")) + test_uprobe_fill_link_info(skel, BPF_PERF_EVENT_URETPROBE); + + qsort(kmulti_syms, KMULTI_CNT, sizeof(kmulti_syms[0]), symbols_cmp_r); + for (i = 0; i < KMULTI_CNT; i++) + kmulti_addrs[i] = ksym_get_addr(kmulti_syms[i]); + if (test__start_subtest("kprobe_multi_link_info")) + test_kprobe_multi_fill_link_info(skel, false, false); + if (test__start_subtest("kretprobe_multi_link_info")) + test_kprobe_multi_fill_link_info(skel, true, false); + if (test__start_subtest("kprobe_multi_invalid_ubuff")) + test_kprobe_multi_fill_link_info(skel, true, true); + +cleanup: + test_fill_link_info__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_fill_link_info.c b/tools/testing/selftests/bpf/progs/test_fill_link_info.c new file mode 100644 index 000000000000..564f402d56fe --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_fill_link_info.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 Yafang Shao */ + +#include "vmlinux.h" +#include +#include + +extern bool CONFIG_X86_KERNEL_IBT __kconfig __weak; + +/* This function is here to have CONFIG_X86_KERNEL_IBT + * used and added to object BTF. + */ +int unused(void) +{ + return CONFIG_X86_KERNEL_IBT ? 0 : 1; +} + +SEC("kprobe") +int BPF_PROG(kprobe_run) +{ + return 0; +} + +SEC("uprobe") +int BPF_PROG(uprobe_run) +{ + return 0; +} + +SEC("tracepoint") +int BPF_PROG(tp_run) +{ + return 0; +} + +SEC("kprobe.multi") +int BPF_PROG(kmulti_run) +{ + return 0; +} + +char _license[] SEC("license") = "GPL";