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: [PATCHv4 bpf-next 25/25] selftests/bpf: Add tracing multi attach rollback tests
Date: Wed, 25 Mar 2026 14:45:59 +0800 [thread overview]
Message-ID: <f222748c-69ce-4c63-826b-4f2d67fd4ec9@linux.dev> (raw)
In-Reply-To: <20260324081846.2334094-26-jolsa@kernel.org>
On 24/3/26 16:18, 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 | 213 ++++++++++++++++++
> .../bpf/progs/tracing_multi_rollback.c | 43 ++++
> 2 files changed, 256 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 6917471e329c..6ff0f72f8c46 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[] = {
> @@ -669,6 +670,218 @@ 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);
> +}
> +
> +
NIT: keep one blank line here.
> +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 *extra_load_and_link(void)
> +{
> + struct tracing_multi_rollback *skel;
> + int err;
> +
> + skel = tracing_multi_rollback__open();
> + if (!ASSERT_OK_PTR(skel, "tracing_multi_rollback__open"))
> + goto cleanup;
> +
> + bpf_program__set_autoload(skel->progs.extra, true);
> +
> + err = tracing_multi_rollback__load(skel);
> + if (!ASSERT_OK(err, "tracing_multi_rollback__load"))
> + goto cleanup;
> +
> + skel->links.extra = bpf_program__attach_trace(skel->progs.extra);
> + if (!ASSERT_OK_PTR(skel->links.extra, "bpf_program__attach_trace"))
> + goto cleanup;
> +
> + return skel;
> +
> +cleanup:
> + tracing_multi_rollback__destroy(skel);
> + return NULL;
> +}
> +
> +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)
> +{
> + struct tracing_multi_rollback *skel, *extra;
> + LIBBPF_OPTS(bpf_tracing_multi_opts, opts);
> + struct tracing_multi_rollback **fillers;
> + 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;
> +
> + extra = extra_load_and_link();
> + if (!ASSERT_OK_PTR(extra, "extra_load_and_link"))
Should cleanup fillers here?
Thanks,
Leon
> + return;
> +
> + skel = tracing_multi_rollback__open();
> + if (!ASSERT_OK_PTR(skel, "tracing_multi_rollback__open"))
> + goto cleanup;
> +
[...]
next prev parent reply other threads:[~2026-03-25 6:46 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-24 8:18 [PATCHv4 bpf-next 00/25] bpf: tracing_multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 01/25] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 02/25] ftrace: Make ftrace_hash_clear global Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 03/25] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 04/25] bpf: Add struct bpf_trampoline_ops object Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 05/25] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 06/25] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 07/25] bpf: Add multi tracing attach types Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 08/25] bpf: Move sleepable verification code to btf_id_allow_sleepable Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 09/25] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-03-24 8:58 ` bot+bpf-ci
2026-03-24 14:29 ` Jiri Olsa
2026-03-27 4:18 ` kernel test robot
2026-03-24 8:18 ` [PATCHv4 bpf-next 10/25] bpf: Add support for tracing multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 11/25] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 12/25] bpf: Add support for tracing_multi link session Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 13/25] bpf: Add support for tracing_multi link fdinfo Jiri Olsa
2026-03-25 6:43 ` Leon Hwang
2026-03-25 21:49 ` Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 14/25] libbpf: Add bpf_object_cleanup_btf function Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 15/25] libbpf: Add bpf_link_create support for tracing_multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 16/25] libbpf: Add btf_type_is_traceable_func function Jiri Olsa
2026-03-24 8:58 ` bot+bpf-ci
2026-03-24 14:29 ` Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 17/25] libbpf: Add support to create tracing multi link Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 18/25] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 19/25] selftests/bpf: Add tracing multi skel/pattern/ids module " Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 20/25] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 21/25] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 22/25] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 23/25] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 24/25] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
2026-03-25 6:45 ` Leon Hwang
2026-03-25 15:11 ` Alexei Starovoitov
2026-03-25 21:48 ` Jiri Olsa
2026-03-25 21:48 ` Jiri Olsa
2026-03-24 8:18 ` [PATCHv4 bpf-next 25/25] selftests/bpf: Add tracing multi attach rollback tests Jiri Olsa
2026-03-25 6:45 ` Leon Hwang [this message]
2026-03-25 21:49 ` Jiri Olsa
2026-03-25 6:42 ` [PATCHv4 bpf-next 00/25] bpf: tracing_multi link Leon Hwang
2026-03-25 14:58 ` Leon Hwang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f222748c-69ce-4c63-826b-4f2d67fd4ec9@linux.dev \
--to=leon.hwang@linux.dev \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=eddyz87@gmail.com \
--cc=jolsa@kernel.org \
--cc=kafai@fb.com \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=menglong8.dong@gmail.com \
--cc=rostedt@kernel.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox