From: Leon Hwang <leon.hwang@linux.dev>
To: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
Martin KaFai Lau <kafai@fb.com>,
Eduard Zingerman <eddyz87@gmail.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
Menglong Dong <menglong8.dong@gmail.com>,
Steven Rostedt <rostedt@kernel.org>
Subject: Re: [PATCHv3 bpf-next 24/24] selftests/bpf: Add tracing multi attach rollback tests
Date: Tue, 17 Mar 2026 11:20:59 +0800 [thread overview]
Message-ID: <d1bfc6ec-3234-4515-a68f-ff48ab9c1570@linux.dev> (raw)
In-Reply-To: <20260316075138.465430-25-jolsa@kernel.org>
On 16/3/26 15:51, Jiri Olsa wrote:
> Adding tests for the rollback code when the tracing_multi
> link won't get attached, covering 2 reasons:
>
> - wrong btf id passed by user, where all previously allocated
> trampolines will be released
> - trampoline for requested function is fully attached (has already
> maximum programs attached) and the link fails, the rollback code
> needs to release all previously link-ed trampolines and release
> them
>
> We need the bpf_fentry_test* unattached for the tests to pass,
> so the rollback tests are serial.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> .../selftests/bpf/prog_tests/tracing_multi.c | 181 ++++++++++++++++++
> .../bpf/progs/tracing_multi_rollback.c | 38 ++++
> 2 files changed, 219 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_rollback.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> index a0fcda51bb6c..10b8cc6b368b 100644
> --- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> +++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> @@ -10,6 +10,7 @@
> #include "tracing_multi_session.skel.h"
> #include "tracing_multi_fail.skel.h"
> #include "tracing_multi_bench.skel.h"
> +#include "tracing_multi_rollback.skel.h"
> #include "trace_helpers.h"
>
> static __u64 bpf_fentry_test_cookies[] = {
> @@ -649,6 +650,186 @@ void serial_test_tracing_multi_bench_attach(void)
> free(ids);
> }
>
> +static void tracing_multi_rollback_run(struct tracing_multi_rollback *skel)
> +{
> + LIBBPF_OPTS(bpf_test_run_opts, topts);
> + int err, prog_fd;
> +
> + prog_fd = bpf_program__fd(skel->progs.test_fentry);
> + err = bpf_prog_test_run_opts(prog_fd, &topts);
> + ASSERT_OK(err, "test_run");
> +
> + /* make sure the rollback code did not leave any program attached */
> + ASSERT_EQ(skel->bss->test_result_fentry, 0, "test_result_fentry");
> + ASSERT_EQ(skel->bss->test_result_fexit, 0, "test_result_fexit");
> +}
> +
> +static void test_rollback_put(void)
> +{
> + LIBBPF_OPTS(bpf_tracing_multi_opts, opts);
> + struct tracing_multi_rollback *skel = NULL;
> + size_t cnt = FUNCS_CNT;
> + __u32 *ids = NULL;
> + int err;
> +
> + skel = tracing_multi_rollback__open();
> + if (!ASSERT_OK_PTR(skel, "tracing_multi_rollback__open"))
> + return;
> +
> + bpf_program__set_autoload(skel->progs.test_fentry, true);
> + bpf_program__set_autoload(skel->progs.test_fexit, true);
> +
> + err = tracing_multi_rollback__load(skel);
> + if (!ASSERT_OK(err, "tracing_multi_rollback__load"))
> + goto cleanup;
> +
> + ids = get_ids(bpf_fentry_test, cnt, NULL);
> + if (!ASSERT_OK_PTR(ids, "get_ids"))
> + goto cleanup;
> +
> + /*
> + * Mangle last id to trigger rollback, which needs to do put
> + * on get-ed trampolines.
> + */
> + ids[9] = 0;
> +
> + opts.ids = ids;
> + opts.cnt = cnt;
> +
> + skel->bss->pid = getpid();
> +
> + skel->links.test_fentry = bpf_program__attach_tracing_multi(skel->progs.test_fentry,
> + NULL, &opts);
> + if (!ASSERT_ERR_PTR(skel->links.test_fentry, "bpf_program__attach_tracing_multi"))
> + goto cleanup;
> +
> + skel->links.test_fexit = bpf_program__attach_tracing_multi(skel->progs.test_fexit,
> + NULL, &opts);
> + if (!ASSERT_ERR_PTR(skel->links.test_fexit, "bpf_program__attach_tracing_multi"))
> + goto cleanup;
> +
> + /* We don't really attach any program, but let's make sure. */
> + tracing_multi_rollback_run(skel);
> +
> +cleanup:
> + tracing_multi_rollback__destroy(skel);
> + free(ids);
> +}
> +
> +
> +static void fillers_cleanup(struct tracing_multi_rollback **skels, int cnt)
> +{
> + int i;
> +
> + for (i = 0; i < cnt; i++)
> + tracing_multi_rollback__destroy(skels[i]);
> +
> + free(skels);
> +}
> +
> +static struct tracing_multi_rollback **fillers_load_and_link(int max)
> +{
> + struct tracing_multi_rollback **skels, *skel;
> + int i, err;
> +
> + skels = calloc(max + 1, sizeof(*skels));
> + if (!ASSERT_OK_PTR(skels, "calloc"))
> + return NULL;
> +
> + for (i = 0; i < max; i++) {
> + skel = skels[i] = tracing_multi_rollback__open();
> + if (!ASSERT_OK_PTR(skels[i], "tracing_multi_rollback__open"))
> + goto cleanup;
> +
> + bpf_program__set_autoload(skel->progs.filler, true);
> +
> + err = tracing_multi_rollback__load(skel);
> + if (!ASSERT_OK(err, "tracing_multi_rollback__load"))
> + goto cleanup;
> +
> + skel->links.filler = bpf_program__attach_trace(skel->progs.filler);
> + if (!ASSERT_OK_PTR(skels[i]->links.filler, "bpf_program__attach_trace"))
> + goto cleanup;
> + }
> +
> + return skels;
> +
> +cleanup:
> + fillers_cleanup(skels, i);
> + return NULL;
> +}
> +
> +static void test_rollback_unlink(void)
> +{
> + LIBBPF_OPTS(bpf_tracing_multi_opts, opts);
> + struct tracing_multi_rollback **fillers;
> + struct tracing_multi_rollback *skel;
> + size_t cnt = FUNCS_CNT;
> + __u32 *ids = NULL;
> + int err, max;
> +
> + max = get_bpf_max_tramp_links();
> + if (!ASSERT_GE(max, 1, "bpf_max_tramp_links"))
> + return;
> +
> + /* Attach maximum allowed programs to bpf_fentry_test10 */
> + fillers = fillers_load_and_link(max);
> + if (!ASSERT_OK_PTR(fillers, "fillers_load_and_link"))
> + return;
> +
> + skel = tracing_multi_rollback__open();
> + if (!ASSERT_OK_PTR(skel, "tracing_multi_rollback__open"))
> + goto cleanup;
> +
> + bpf_program__set_autoload(skel->progs.test_fentry, true);
> + bpf_program__set_autoload(skel->progs.test_fexit, true);
> +
> + /*
> + * Attach tracing_multi link on bpf_fentry_test1-10, which will
> + * fail on bpf_fentry_test10 function, because it already has
> + * maximum allowed programs attached.
> + *
> + * The rollback needs to unlink already link-ed trampolines and
> + * put all of them.
> + */
> + err = tracing_multi_rollback__load(skel);
> + if (!ASSERT_OK(err, "tracing_multi_rollback__load"))
> + goto cleanup;
> +
> + ids = get_ids(bpf_fentry_test, cnt, NULL);
> + if (!ASSERT_OK_PTR(ids, "get_ids"))
> + goto cleanup;
> +
> + opts.ids = ids;
> + opts.cnt = cnt;
> +
> + skel->bss->pid = getpid();
> +
> + skel->links.test_fentry = bpf_program__attach_tracing_multi(skel->progs.test_fentry,
> + NULL, &opts);
> + if (!ASSERT_ERR_PTR(skel->links.test_fentry, "bpf_program__attach_tracing_multi"))
> + goto cleanup;
> +
> + skel->links.test_fexit = bpf_program__attach_tracing_multi(skel->progs.test_fexit,
> + NULL, &opts);
> + if (!ASSERT_ERR_PTR(skel->links.test_fexit, "bpf_program__attach_tracing_multi"))
> + goto cleanup;
> +
> + tracing_multi_rollback_run(skel);
> +
> +cleanup:
tracing_multi_rollback__destroy(skel); is missed to destroy skel?
Thanks,
Leon
> + fillers_cleanup(fillers, max);
> + free(ids);
> +}
> +
> +void serial_test_tracing_multi_attach_rollback(void)
> +{
> + if (test__start_subtest("put"))
> + test_rollback_put();
> + if (test__start_subtest("unlink"))
> + test_rollback_unlink();
> +}
> +
> void test_tracing_multi_test(void)
> {
> #ifndef __x86_64__
> diff --git a/tools/testing/selftests/bpf/progs/tracing_multi_rollback.c b/tools/testing/selftests/bpf/progs/tracing_multi_rollback.c
> new file mode 100644
> index 000000000000..eb27869f551a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/tracing_multi_rollback.c
> @@ -0,0 +1,38 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <stdbool.h>
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +
> +char _license[] SEC("license") = "GPL";
> +
> +int pid = 0;
> +
> +__u64 test_result_fentry = 0;
> +__u64 test_result_fexit = 0;
> +
> +SEC("?fentry.multi")
> +int BPF_PROG(test_fentry)
> +{
> + if (bpf_get_current_pid_tgid() >> 32 != pid)
> + return 0;
> +
> + test_result_fentry++;
> + return 0;
> +}
> +
> +SEC("?fexit.multi")
> +int BPF_PROG(test_fexit)
> +{
> + if (bpf_get_current_pid_tgid() >> 32 != pid)
> + return 0;
> +
> + test_result_fexit++;
> + return 0;
> +}
> +
> +SEC("?fentry/bpf_fentry_test10")
> +int BPF_PROG(filler)
> +{
> + return 0;
> +}
next prev parent reply other threads:[~2026-03-17 3:21 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-16 7:51 [PATCHv3 bpf-next 00/24] bpf: tracing_multi link Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 01/24] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 02/24] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-03-16 8:35 ` bot+bpf-ci
2026-03-16 21:16 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 03/24] bpf: Add struct bpf_trampoline_ops object Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 04/24] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 05/24] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 06/24] bpf: Add multi tracing attach types Jiri Olsa
2026-03-19 16:31 ` kernel test robot
2026-03-19 18:29 ` kernel test robot
2026-03-16 7:51 ` [PATCHv3 bpf-next 07/24] bpf: Move sleepable verification code to btf_id_allow_sleepable Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 08/24] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-03-16 8:35 ` bot+bpf-ci
2026-03-16 21:16 ` Jiri Olsa
2026-03-20 10:18 ` kernel test robot
2026-03-16 7:51 ` [PATCHv3 bpf-next 09/24] bpf: Add support for tracing multi link Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 10/24] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 11/24] bpf: Add support for tracing_multi link session Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 12/24] bpf: Add support for tracing_multi link fdinfo Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 13/24] libbpf: Add bpf_object_cleanup_btf function Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 14/24] libbpf: Add bpf_link_create support for tracing_multi link Jiri Olsa
2026-03-16 8:35 ` bot+bpf-ci
2026-03-16 21:16 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 15/24] libbpf: Add btf_type_is_traceable_func function Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 16/24] libbpf: Add support to create tracing multi link Jiri Olsa
2026-03-16 8:35 ` bot+bpf-ci
2026-03-16 21:16 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 17/24] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-03-17 3:04 ` Leon Hwang
2026-03-17 17:18 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 18/24] selftests/bpf: Add tracing multi skel/pattern/ids module " Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 19/24] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-03-17 3:05 ` Leon Hwang
2026-03-17 17:18 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 20/24] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-03-17 3:06 ` Leon Hwang
2026-03-17 17:18 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 21/24] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 22/24] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-03-17 3:06 ` Leon Hwang
2026-03-17 17:19 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 23/24] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
2026-03-17 3:09 ` Leon Hwang
2026-03-17 17:19 ` Jiri Olsa
2026-03-16 7:51 ` [PATCHv3 bpf-next 24/24] selftests/bpf: Add tracing multi attach rollback tests Jiri Olsa
2026-03-17 3:20 ` Leon Hwang [this message]
2026-03-17 17:19 ` Jiri Olsa
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