On Sun, Oct 9, 2022 at 3:00 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Adding kprobe_multi kmod link api tests that attach bpf_testmod
> functions via kprobe_multi link API.
>
> Running it as serial test, because we don't want other tests to
> reload bpf_testmod while it's running.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> .../prog_tests/kprobe_multi_testmod_test.c | 94 +++++++++++++++++++
> .../selftests/bpf/progs/kprobe_multi.c | 51 ++++++++++
> 2 files changed, 145 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c
> new file mode 100644
> index 000000000000..5fe02572650a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <test_progs.h>
> +#include "kprobe_multi.skel.h"
> +#include "trace_helpers.h"
> +#include "bpf/libbpf_internal.h"
> +
> +static void kprobe_multi_testmod_check(struct kprobe_multi *skel)
> +{
> + ASSERT_EQ(skel->bss->kprobe_testmod_test1_result, 1, "kprobe_test1_result");
> + ASSERT_EQ(skel->bss->kprobe_testmod_test2_result, 1, "kprobe_test2_result");
> + ASSERT_EQ(skel->bss->kprobe_testmod_test3_result, 1, "kprobe_test3_result");
> +
> + ASSERT_EQ(skel->bss->kretprobe_testmod_test1_result, 1, "kretprobe_test1_result");
> + ASSERT_EQ(skel->bss->kretprobe_testmod_test2_result, 1, "kretprobe_test2_result");
> + ASSERT_EQ(skel->bss->kretprobe_testmod_test3_result, 1, "kretprobe_test3_result");
> +}
> +
> +static void test_testmod_link_api(struct bpf_link_create_opts *opts)
> +{
> + int prog_fd, link1_fd = -1, link2_fd = -1;
> + struct kprobe_multi *skel = NULL;
> +
> + skel = kprobe_multi__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load"))
> + goto cleanup;
> +
> + skel->bss->pid = getpid();
> + prog_fd = bpf_program__fd(skel->progs.test_kprobe_testmod);
> + link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, opts);
> + if (!ASSERT_GE(link1_fd, 0, "link_fd1"))
> + goto cleanup;
> +
> + opts->kprobe_multi.flags = BPF_F_KPROBE_MULTI_RETURN;
> + prog_fd = bpf_program__fd(skel->progs.test_kretprobe_testmod);
> + link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, opts);
> + if (!ASSERT_GE(link2_fd, 0, "link_fd2"))
> + goto cleanup;
> +
any reason to not use bpf_program__attach_kprobe_multi_ops() and
instead use low-level bpf_link_create?
> + ASSERT_OK(trigger_module_test_read(1), "trigger_read");
> + kprobe_multi_testmod_check(skel);
> +
> +cleanup:
> + if (link1_fd != -1)
> + close(link1_fd);
> + if (link2_fd != -1)
> + close(link2_fd);
you don't need to even do this if you stick to high-level attach APIs
> + kprobe_multi__destroy(skel);
> +}
> +
> +#define GET_ADDR(__sym, __addr) ({ \
> + __addr = ksym_get_addr(__sym); \
> + if (!ASSERT_NEQ(__addr, 0, "kallsyms load failed for " #__sym)) \
> + return; \
> +})
macro for this? why? just make understanding the code and debugging
it, if necessary, harder. You don't even need that return, just lookup
and ASSERT_NEQ(). Go to symbol #2 and do the same. If something goes
wrong you'll have three failed ASSERT_NEQs, which is totally fine.
> +
> +static void test_testmod_link_api_addrs(void)
> +{
> + LIBBPF_OPTS(bpf_link_create_opts, opts);
> + unsigned long long addrs[3];
> +
> + GET_ADDR("bpf_testmod_fentry_test1", addrs[0]);
> + GET_ADDR("bpf_testmod_fentry_test2", addrs[1]);
> + GET_ADDR("bpf_testmod_fentry_test3", addrs[2]);
> +
> + opts.kprobe_multi.addrs = (const unsigned long *) addrs;
> + opts.kprobe_multi.cnt = ARRAY_SIZE(addrs);
> +
> + test_testmod_link_api(&opts);
> +}
> +
> +static void test_testmod_link_api_syms(void)
> +{
> + LIBBPF_OPTS(bpf_link_create_opts, opts);
> + const char *syms[3] = {
> + "bpf_testmod_fentry_test1",
> + "bpf_testmod_fentry_test2",
> + "bpf_testmod_fentry_test3",
> + };
> +
> + opts.kprobe_multi.syms = syms;
> + opts.kprobe_multi.cnt = ARRAY_SIZE(syms);
> + test_testmod_link_api(&opts);
> +}
> +
> +void serial_test_kprobe_multi_testmod_test(void)
> +{
> + if (!ASSERT_OK(load_kallsyms_refresh(), "load_kallsyms_refresh"))
> + return;
> +
> + if (test__start_subtest("testmod_link_api_syms"))
> + test_testmod_link_api_syms();
> + if (test__start_subtest("testmod_link_api_addrs"))
> + test_testmod_link_api_addrs();
> +}
> diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c
> index 98c3399e15c0..b3c54ec13a45 100644
> --- a/tools/testing/selftests/bpf/progs/kprobe_multi.c
> +++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c
> @@ -110,3 +110,54 @@ int test_kretprobe_manual(struct pt_regs *ctx)
> kprobe_multi_check(ctx, true);
> return 0;
> }
> +
> +extern const void bpf_testmod_fentry_test1 __ksym;
> +extern const void bpf_testmod_fentry_test2 __ksym;
> +extern const void bpf_testmod_fentry_test3 __ksym;
> +
> +__u64 kprobe_testmod_test1_result = 0;
> +__u64 kprobe_testmod_test2_result = 0;
> +__u64 kprobe_testmod_test3_result = 0;
> +
> +__u64 kretprobe_testmod_test1_result = 0;
> +__u64 kretprobe_testmod_test2_result = 0;
> +__u64 kretprobe_testmod_test3_result = 0;
> +
> +static void kprobe_multi_testmod_check(void *ctx, bool is_return)
> +{
> + if (bpf_get_current_pid_tgid() >> 32 != pid)
> + return;
> +
> + __u64 addr = bpf_get_func_ip(ctx);
> +
> +#define SET(__var, __addr) ({ \
> + if ((const void *) addr == __addr) \
> + __var = 1; \
> +})
> +
same feedback, why macro for this? There is nothing repetitive done in it at all
> + if (is_return) {
> + SET(kretprobe_testmod_test1_result, &bpf_testmod_fentry_test1);
> + SET(kretprobe_testmod_test2_result, &bpf_testmod_fentry_test2);
> + SET(kretprobe_testmod_test3_result, &bpf_testmod_fentry_test3);
> + } else {
> + SET(kprobe_testmod_test1_result, &bpf_testmod_fentry_test1);
> + SET(kprobe_testmod_test2_result, &bpf_testmod_fentry_test2);
> + SET(kprobe_testmod_test3_result, &bpf_testmod_fentry_test3);
> + }
> +
> +#undef SET
> +}
> +
> +SEC("kprobe.multi")
> +int test_kprobe_testmod(struct pt_regs *ctx)
> +{
> + kprobe_multi_testmod_check(ctx, false);
> + return 0;
> +}
> +
> +SEC("kretprobe.multi")
> +int test_kretprobe_testmod(struct pt_regs *ctx)
> +{
> + kprobe_multi_testmod_check(ctx, true);
> + return 0;
> +}
> --
> 2.37.3
>
